Home About us Contact
|
Home About us Contact | ||
|
|
||
RV
Terms modified by RV Selected AbstractsRegional variations in action potential alternans in isolated murine Scn5a+/, hearts during dynamic pacingACTA PHYSIOLOGICA, Issue 2 2010G. D. K. Matthews Abstract Aim:, Clinical observations suggest that alternans in action potential (AP) characteristics presages breakdown of normal ordered cardiac electrical activity culminating in ventricular arrhythmogenesis. We compared such temporal nonuniformities in monophasic action potential (MAP) waveforms in left (LV) and right ventricular (RV) epicardia and endocardia of Langendorff-perfused murine wild-type (WT), and Scn5a+/, hearts modelling Brugada syndrome (BrS) for the first time. Methods:, A dynamic pacing protocol imposed successively incremented steady pacing rates between 5.5 and 33 Hz. A signal analysis algorithm detected sequences of >10 beats showing alternans. Results were compared before and following the introduction of flecainide (10 ,m) and quinidine (5 ,m) known to exert pro- and anti-arrhythmic effects in BrS. Results:, Sustained and transient amplitude and duration alternans were both frequently followed by ventricular ectopic beats and ventricular tachycardia or fibrillation. Diastolic intervals (DIs) that coincided with onsets of transient (tr) or sustained (ss) alternans in MAP duration (DI*) and amplitude (DI,) were determined. Kruskal,Wallis tests followed by Bonferroni-corrected Mann,Whitney U -tests were applied to these DI results sorted by recording site, pharmacological conditions or experimental populations. WT hearts showed no significant heterogeneities in any DI. Untreated Scn5a+/, hearts showed earlier onsets of transient but not sustained duration alternans in LV endocardium compared with RV endocardium or LV epicardium. Flecainide administration caused earlier onsets of both transient and sustained duration alternans selectively in the RV epicardium in the Scn5a+/, hearts. Conclusion:, These findings in a genetic model thus implicate RV epicardial changes in the arrhythmogenicity produced by flecainide challenge in previously asymptomatic clinical BrS. [source] Downregulation of oxytocin receptors in right ventricle of rats with monocrotaline-induced pulmonary hypertensionACTA PHYSIOLOGICA, Issue 2 2010T. L. Broderick Abstract Aim:, Pulmonary hypertension (PH) in the rat leads to right ventricular (RV) hypertrophy, inflammation and increased natriuretic peptide (NP) levels in plasma and RV. Because the release of nitric oxide (NO) and atrial natriuretic peptide (ANP) is a function of the oxytocin receptor (OTR), we examined the effect of PH on gene and protein expression of OTR, NP (A, atrial; B, brain) and receptors (NPRs), nitric oxide synthases (NOS), interleukin (IL)-1,, IL-6 and tumour necrosis factor-, in the hypertrophied RV in a model of PH. Methods:, RV hypertrophy was induced in male Sprague,Dawley rats with monocrotaline (MCT; 60 mg kg,1) and was confirmed by the presence of an increased RV weight and RV-to-[left ventricle (LV) and septum] ratio. Results:, In the RV of MCT-treated rats, a ,40% reduction in OTR mRNA and protein was observed compared with the RV of control rats. This reduction was associated with increased transcripts of ANP and BNP in both ventricles and a corresponding increase in NP receptor mRNA expression for receptors A, B and C. Protein expression of inducible NOS was increased in the RV, whereas endothelial NOS transcripts were increased only in the LV of MCT-treated rats. In the RV of MCT-treated rats, downregulation of OTR was also associated with increased mRNA expression of IL-1, and IL-6. Conclusion:, Our results show that downregulation of the OTR in the RV of MCT-treated rats is associated with increased expression of NP and their receptors as well as IL-1, and IL-6. This reduction in OTR in RV myocardium may have an impact on cardiac function in the MCT-induced model of PH. [source] Right Ventricular Function in Congenital Heart Defects Assessed by Regional Wall MotionCONGENITAL HEART DISEASE, Issue 3 2010FSCAI, Michael R. Nihill MB ABSTRACT Objectives., To develop a simple method to assess right ventricular function by angiography. Background., Conventional methods of evaluating right ventricular function are inaccurate, cumbersome, and expensive. Methods., We analyzed biplane right ventricular angiograms taken in the posterior,anterior and lateral projections using software to measure right ventricular volumes and regional wall motion in 78 patients with normal hearts (n = 29), atrial septal defects (ASD n = 13), pulmonary valve stenosis (PVS n = 21), and postoperative atrial switch patients (n = 15). We also measured the shortening fraction (SF) from the midtricuspid annulus to the septum and correlated various angiographic measurements with the right ventricular (RV) ejection fraction. Results., The volume-overloaded patients (ASD) had larger end diastolic volumes and increased SF compared with normal patients, while the pressure-loaded patients (PVS) had normal volumes and SF. The postoperative atrial switch patients had decreased systolic function and increased end diastolic volume. The SF for all of the patients correlated with the ejection fraction (r= 0.785, P, .0001). Conclusions., A simple measurement of the end diastolic and end systolic distance from the midtricuspid annulus to the septum (SF) provides a good index of RV function by angiography and correlates well with RV ejection fraction. [source] Outcome of Pulmonary Valve Replacements in Adults after Tetralogy Repair: A Multi-institutional StudyCONGENITAL HEART DISEASE, Issue 3 2008Thomas P. Graham Jr. MD ABSTRACT Objective., The purpose of this study was to assess the outcome of pulmonary valve replacement (PVR) in adults with moderate/severe pulmonary regurgitation after tetralogy repair, with particular emphasis on patient outcome, durability of valve repair, and improvement in symptomatology. Design/Setting/Patients., The project committee of the International Society of Congenital Heart Disease undertook a retrospective multi-institutional analysis of PVR. Seven centers participated in submitting data on 93 patients >18 years of age who had the operation performed and follow-up obtained. The average age of PVR was 26± years (median 27 years). Time of follow-up after replacement was 3 years (range 4 days,28 years). Outcomes/Measures/Results., Kaplan,Meier estimates of durability of PVR showed approximately 50% replacement at 11 years. There were two deaths at 6 and 12 months after valve replacement. Right ventricular (RV) size estimated by echocardiography from pre- to postoperative studies decreased in 81% (P < 0.001 testing for equal proportions), but RV systolic function increased in only 36% (P = 0.09). Ability index improved in 59% (P < 0.001) and clinical heart failure status improved in 57% with this problem before PVR. PVR did not improve arrhythmia status in a small group of patients. Conclusions., PVR is associated with low mortality, decrease in RV size and improvement in ability index, and uncertain effects on RV systolic function. Average valve durability was approximately 11 years. Criteria for PVR that will preserve RV function are not clearly identified, and management of these patients remains a difficult enterprise. [source] Large Apical Muscular Ventricular Septal Defect: Asymptomatic due to Anomalous Muscle Bundles in the Right VentricleCONGENITAL HEART DISEASE, Issue 1 2007Anant Khositseth MD ABSTRACT This case report demonstrated an apical muscular ventricular septal defect (VSD) that was a large defect but behaved like a small defect because of the restrictive flow across the anomalous muscle bundles in the right ventricular (RV) apex. The anomalous muscle bundles separated the RV sinus into two parts: the RV apex connecting with the left ventricle through the apical muscular VSD on one side, and the rest of the RV sinus connecting with RV inflow and RV outflow on the other side. These findings explained why the 11-year-old girl in this study remained asymptomatic without evidence of volume load. Thus far, it was not necessary to close her defect because of the hemodynamic insignificance. [source] Short-Term Effects of Right Ventricular Pacing on Cardiorespiratory Function in Patients With a Biventricular PacemakerCONGESTIVE HEART FAILURE, Issue 6 2008Stefan Toggweiler MD The intention of this study was to evaluate the short-term effect of right ventricular (RV) pacing on cardiorespiratory function in patients with a biventricular pacemaker. A group of 26 patients with a biventricular pacemaker was enrolled in this cross-over, single-blind study. All patients underwent spiroergometry and electrocardiography in RV and biventricular pacing mode. Peak work capacity (102±32 W and 107±34 W for RV and biventricular pacing mode, respectively; P<.01) and peak oxygen consumption (21.4±6.7 mL/min/kg and 22.6±7.0 mL/min/kg for RV and biventricular pacing mode, respectively; P<.01) were significantly lower in the RV pacing mode. Heart rate at rest was significantly higher with active RV pacing. Short-term RV pacing in patients with a biventricular pacemaker resulted in a higher heart rate at rest, a lower peak work capacity, and a lower peak oxygen consumption compared with that in the biventricular pacing mode. [source] Presence of Biventricular Dysfunction in Patients With Type II Diabetes MellitusCONGESTIVE HEART FAILURE, Issue 2 2007Mohammad-Reza Movahed MD Diabetes mellitus (DM) has been found to be associated with depressed left ventricular (LV) function. Right ventricular (RV) function in DM patients, however, has not been well studied. The goal of this study was to evaluate the occurrence of LV and RV dysfunction in patients with DM. A series of 157 patients underwent simultaneous measurement of LV ejection fraction (LVEF) and RV ejection fraction (RVEF). Four of 26 DM patients had RVEF <30% (15.4%) vs 4 of 126 controls (3.2%) (P=.01). Eleven of 27 (40.7%) patients with DM had LVEF <30% vs 9 of 128 controls (7%) (P<.0001). Using multivariate analysis, DM remained independently associated with severely decreased biventricular function (RVEF <30%; odds ratio, 5.7; confidence interval, 1.3,25.4 [P=.02] and LVEF <30%; odds ratio, 12.9; confidence interval, 3.8,43.7 [P<.0001]). These results suggest that diabetic cardiomyopathy involves both ventricles as an independent pathologic process. [source] Protein kinase C mRNA and protein expressions in hypobaric hypoxia-induced cardiac hypertrophy in ratsACTA PHYSIOLOGICA, Issue 4 2010M. Uenoyama Abstract Aim:, Protein kinase C (PKC), cloned as a serine/threonine kinase, plays key roles in diverse intracellular signalling processes and in cardiovascular remodelling during pressure overload or volume overload. We looked for correlations between changes in PKC isoforms (levels and/or subcellular distributions) and cardiac remodelling during experimental hypobaric hypoxic environment (HHE)-induced pulmonary hypertension. Methods:, To study the PKC system in the heart during HHE, 148 male Wistar rats were housed for up to 21 days in a chamber at the equivalent of 5500 m altitude level (10% O2). Results:, At 14 or more days of exposure to HHE, pulmonary arterial pressure (PAP) was significantly increased. In the right ventricle (RV): (1) the expression of PKC-, protein in the cytosolic and membrane fractions was increased at 3,14 days and at 5,7 days of exposure respectively; (ii) the cytosolic expression of PKC-, protein was increased at 1,5, 14 and 21 days of exposure; (3) the membrane expressions of the proteins were decreased at 14,21 (PKC-,II), 14,21 (PKC-,), and 0.5,5 and 21 (PKC-,) days of exposure; (4) the expression of the active form of PKC-, protein on the plasma membrane was increased at 3 days of exposure (based on semiquantitative analysis of the immunohistochemistry). In the left ventricle, the expressions of the PKC mRNAs, and of their cytosolic and membrane proteins, were almost unchanged. The above changes in PKC-,, which were strongly evident in the RV, occurred alongside the increase in PAP. Conclusion:, PKC-, may help to modulate the right ventricular hypertrophy caused by pulmonary hypertension in HHE. [source] Electrophysiological determinants of hypokalaemia-induced arrhythmogenicity in the guinea-pig heartACTA PHYSIOLOGICA, Issue 4 2009O. E. Osadchii Abstract Aim:, Hypokalaemia is an independent risk factor contributing to arrhythmic death in cardiac patients. In the present study, we explored the mechanisms of hypokalaemia-induced tachyarrhythmias by measuring ventricular refractoriness, spatial repolarization gradients, and ventricular conduction time in isolated, perfused guinea-pig heart preparations. Methods:, Epicardial and endocardial monophasic action potentials from distinct left ventricular (LV) and right ventricular (RV) recording sites were monitored simultaneously with volume-conducted electrocardiogram (ECG) during steady-state pacing and following a premature extrastimulus application at progressively reducing coupling stimulation intervals in normokalaemic and hypokalaemic conditions. Results:, Hypokalaemic perfusion (2.5 mm K+ for 30 min) markedly increased the inducibility of tachyarrhythmias by programmed ventricular stimulation and rapid pacing, prolonged ventricular repolarization and shortened LV epicardial and endocardial effective refractory periods, thereby increasing the critical interval for LV re-excitation. Hypokalaemia increased the RV-to-LV transepicardial repolarization gradients but had no effect on transmural dispersion of APD90 and refractoriness across the LV wall. As determined by local activation time recordings, the LV-to-RV transepicardial conduction and the LV transmural (epicardial-to-endocardial) conduction were slowed in hypokalaemic heart preparations. This change was attributed to depressed diastolic excitability as evidenced by increased ventricular pacing thresholds. Conclusion:, These findings suggest that hypokalaemia-induced arrhythmogenicity is attributed to shortened LV refractoriness, increased critical intervals for LV re-excitation, amplified RV-to-LV transepicardial repolarization gradients and slowed ventricular conduction in the guinea-pig heart. [source] Kinetic studies on the influence of temperature and growth rate history on crystal growthCRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2008P. M. Martins Abstract Crystallization experiments of sucrose were performed in a batch crystallizer to study the effect of temperature and growth rate history on the crystal growth kinetics. In one of the growth methods adopted, the isothermal volumetric growth rate (RV) is determined as a function of supersaturation (S) at 35, 40 and 45 ºC. In the other, crystals are allowed to grow at constant supersaturation by automatically controlling the solution temperature as the solute concentration decreased. Using the latter method RV is calculated as the solution is cooled. The obtained results are interpreted using empirical, engineering and fundamental perspectives of crystal growth. Firstly, the overall activation energy (EA) is determined from the empirical growth constants obtained in the isothermal method. The concept of falsified kinetics, widely used in chemical reaction engineering, is then extended to the crystal growth of sucrose in order to estimate the true activation energy (ET) from the diffusion-affected constant, EA. The differences found in the isothermal and constant supersaturation methods are explained from the viewpoint of the spiral nucleation mechanism, taking into account different crystal surface properties caused by the growth rate history in each method. Finally, the crystal growth curve obtained in the batch crystallizer at 40 ºC is compared with the one obtained in a fluidized bed crystallizer at the same temperature. Apparently divergent results are explained by the effects of crystal size, hydrodynamic conditions and growth rate history on the crystallization kinetics of sucrose. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Respiratory muscle performance with stretch-shortening cycle manoeuvres: maximal inspiratory pressure,flow curvesACTA PHYSIOLOGICA, Issue 3 2005G. E. Tzelepis Abstract Aim:, To test the hypothesis that the maximal inspiratory muscle (IM) performance, as assessed by the maximal IM pressure,flow relationship, is enhanced with the stretch-shortening cycle (SSC). Methods:, Maximal inspiratory flow,pressure curves were measured in 12 healthy volunteers (35 ± 6 years) during maximal single efforts through a range of graded resistors (4-, 6-, and 8-mm diameter orifices), against an occluded airway, and with a minimal load (wide-open resistor). Maximal inspiratory efforts were initiated at a volume near residual lung volume (RV). The subjects exhaled to RV using slow (S) or fast (F) manoeuvres. With the S manoeuvre, they exhaled slowly to RV and held the breath at RV for about 4 s prior to maximal inspiration. With the F manoeuvre, they exhaled rapidly to RV and immediately inhaled maximally without a post-expiratory hold; a strategy designed to enhance inspiratory pressure via the SSC. Results:, The maximal inspiratory pressure,flow relationship was linear with the S and F manoeuvres (r2 = 0.88 for S and r2 = 0.88 for F manoeuvre, P < 0.0005 in all subjects). With the F manoeuvre, the pressure,flow relationship shifted to the right in a parallel fashion and the calculated maximal power increased by approximately 10% (P < 0.05) over that calculated with the S manoeuvre. Conclusion:, The maximal inspiratory pressure,flow capacity can be enhanced with SSC manoeuvres in a manner analogous to increases in the force,velocity relationship with SSC reported for skeletal muscles. [source] New Annular Tissue Doppler Markers of Pulmonary HypertensionECHOCARDIOGRAPHY, Issue 8 2010Angel López-Candales M.D., F.A.C.C., F.A.S.E. Background: Tissue Doppler imaging (TDI) of mitral (MA) and tricuspid annulus (TA) events characterizes systolic and diastolic properties of each respective ventricle. However, the effect of chronic pulmonary hypertension (cPH) on these TDI annular events has not been well described. Methods: Measurements of right ventricular (RV) performance with TDI of the lateral mitral and tricuspid annuli, to measure isovolumic contraction (IVC) and systolic (S) signals were recorded from 50 individuals without PH and from 50 patients with cPH. To avoid confounding variables, all patients had normal left ventricular ejection fraction and were in normal sinus rhythm at the time of the examination. Results: As expected, markers of RV systolic performance were markedly reduced while LV systolic function remained largely unaffected in cPH patients when compared to patients without PH. TDI interrogation of the MA revealed lengthening of the time interval between IVC and systolic signal (70 ± 17 msec) when compared to individuals without PH (43 ± 8 msec; P < 0.0001). In contrast, cPH markedly shortened the time interval between IVC and the TA systolic signal (34 ± 12 msec) when compared to individuals without PH (65 ± 17 msec; P < 0.0001). Conclusions: cPH lengthens time interval between the IVC and the MA systolic signal while shortening this same interval when the TA is interrogated with TDI; reflecting the potential influence that cPH exerts in biventricular performance. Whether measuring these intervals be routinely used in the follow-up of cPH patients will require further study. (Echocardiography 2010;27:969-976) [source] Incremental Value of Live/Real Time Three-Dimensional Transthoracic Echocardiography in the Assessment of Right Ventricular MassesECHOCARDIOGRAPHY, Issue 5 2009Venkataramana K. Reddy M.D. This case series demonstrates the incremental value of three-dimensional transthoracic echocardiography (3D TTE) over two-dimensional transthoracic echocardiography (2D TTE) in the assessment of 11 patients with right ventricular (RV) masses or mass-like lesions (three cases of RV thrombus, one myxoma, one fibroma, one lipoma, one chordoma, and one sarcoma and three cases of RV noncompaction, which are considered to be mass-like in nature). 3D TTE was of incremental value in the assessment of these masses in that 3D TTE has the capacity to section the mass and view it from multiple angles, giving the examiner a more comprehensive assessment of the mass. This was particularly helpful in the cases of thrombi, as the presence of echolucencies indicated clot lysis. In addition, certainty in the number of thrombi present was an advantage of 3D TTE. Also, sectioning of cardiac tumors allowed more confidence in narrowing the differential diagnosis of the etiology of the mass. In addition, 3D TTE allowed us to identify precise location of the attachments of the masses as well as to determine whether there were mobile components to the mass. Another noteworthy advantage of 3D TTE was that the volumes of the masses could be calculated. Additionally, the findings by 3D TTE correlated well with pathologic examination of RV tumors, and some of the masses measured larger by 3D TTE than by 2D TTE, which was also validated in one case by surgery. As in the case of RV fibroma, another advantage was that 3D TTE actually identified more masses than 2D TTE. RV noncompaction was also well studied, and the assessment with 3D TTE helped to give a more definitive diagnosis in these patients. [source] Right Ventricular Adaptations Along with Left Ventricular Remodeling in Older AthletesECHOCARDIOGRAPHY, Issue 3 2009Oner Ozdogan M.D. Background: Afterload changes and anatomic interaction between the ventricles cause right ventricle (RV) adaptation along with left ventricle (LV) remodeling. This study was designed to evaluate RV adaptations along with LV remodeling and to determine the effect of aging on both ventricles in a population of older athletes. Methods: Echocardiographic characteristics of 48 endurance trained older athletes were examined by tissue Doppler imaging (TDI) and integrated backscatter (IBS). Results: Mean LV mass index was calculated as 107.8±17.0 g/m2. Twenty-two athletes were > 55 years old. Age was found to be a risk factor for diastolic dysfunction regarding lateral TDI velocities (Em < Am) (r = 0.385, P < 0.001). RV long-axis (LAX) diameters were associated with LA volumes and LV masses (r = 0.380, P < 0.01 and r = 0.307, P < 0.05). RV LAX diameters were correlated with RV TDI E-wave (r =,0.285, P < 0.05), RV LAX average, and peak IBS values (r = 0.36, P < 0.05 and r = 0.348, P < 0.05). Conclusions: TDI and IBS are applicable methods to evaluate the relationship between the two ventricles in athletes' heart. Increased RV LAX IBS values indicate increased LV mass and LA volume as a result of RV changes along with LV remodeling. Our data suggest that RV TDI E-wave and average RV IBS values reflect cardiac adaptations of both RV and LV in older athletes. [source] Effects of Continuous Positive Airway Pressure Therapy on Right Ventricular Function Assessment by Tissue Doppler Imaging in Patients with Obstructive Sleep Apnea SyndromeECHOCARDIOGRAPHY, Issue 10 2008Nihal Akar Bayram M.D. Objectives: The effects of continuous positive airway pressure (CPAP) therapy on right ventricular (RV) function in patients with obstructive sleep apnea syndrome (OSAS) has not been previously studied by tissue Doppler imaging (TDI). The aim of this study was to assess RV function using TDI in patients with OSAS before and after CPAP therapy. Methods: Twenty-eight patients with newly diagnosed OSAS in the absence of any confounding factors and 18 controls were included in this study. The peak systolic velocity (S,m), early (E,m) and late (A,m) diastolic myocardial peak velocities at tricuspid lateral annulus, isovolumic acceleration (IVA), myocardial precontraction time (PCT,m), myocardial contraction time (CT,m), and myocardial relaxation time (RT,m) were measured. All echocardiographic parameters were calculated 6 months after CPAP therapy. Results: The RV diastolic parameters such as E,m velocity and E,m-to-A,m ratio were significantly lower, RT,m was significantly prolonged, A,m velocity was similar in patients with OSAS compared to controls; and the RV systolic parameters such as IVA and CT,m were significantly lower and S,m was similar in patients with OSAS compared to controls. At the end of the treatment, 20 of 28 patients were compliant with CPAP therapy. E,m velocity, E,m-to-A,m ratio, IVA, and CT,m increased, PCT,m, PCT,m-to-CT,m ratio, and RT,m decreased significantly after therapy, whereas S,m velocity and A,m velocity did not change after CPAP treatment in the compliant patients. Conclusion: OSAS is associated with RV systolic and diastolic dysfunction, and 6 months of CPAP therapy improves the RV systolic and diastolic dysfunction. [source] Right Ventricular Dimensions and Function in Isolated Left Bundle Branch Block: Is There Evidence of Biventricular Involvement?ECHOCARDIOGRAPHY, Issue 5 2008Jeroen Van Dijk M.D. Background: Isolated left bundle branch block (LBBB) may be an expression of idiopathic cardiomyopathy affecting both ventricles. The present study was conducted to evaluate right ventricular (RV) dimensions and function in asymptomatic LBBB patients with mildly depressed left ventricular (LV) function. Methods: Fifteen patients with asymptomatic LBBB in whom coronary artery disease, hypertension, and valvular pathology was excluded were studied. Fifteen healthy volunteers and 15 idiopathic dilated cardiomyopathy LBBB patients served as controls. RV long axis and tricuspid annulus diameter were obtained, as were tricuspid annular plane systolic excursion (TAPSE) and peak systolic velocity (Sm) of the RV free wall annulus. Tricuspid regurgitation (TR) jets (peak TR jets) were used for RV pressure assessment. Results: RV dimensions were comparable between the asymptomatic LBBB patients and controls. RV functions of healthy volunteers and asymptomatic LBBB patients were similar (TAPSE: 24 ± 3 and 24 ± 4 mm, Sm: 13 ± 2 and 13 ± 3 cm/s, respectively), whereas functional parameters in idiopathic dilated cardiomyopathy patients were significantly reduced (TAPSE: 19 ± 5 mm, Sm: 9 ± 2 cm/s, both P < 0.01 by analysis of variance [ANOVA]). For the three groups combined, a significant inverse correlation between RV pressure (peak TR jets) and RV function (Sm) was observed (r =,0.52, P = 0.017). Conclusions: In patients with an asymptomatic LBBB, RV dimensions and function are within normal range. The present study suggests that screening of RV functional parameters in asymptomatic LBBB patients is not useful for identification of an early-stage cardiomyopathy, and RV dysfunction is merely a consequence of increased RV loading conditions caused by left-sided heart failure and does not indicate a generalized cardiomyopathy affecting both ventricles. [source] Detection of Subclinical Cardiac Involvement in Systemic Sclerosis by Echocardiographic Strain ImagingECHOCARDIOGRAPHY, Issue 2 2008Alper Kepez M.D. Background: Cardiac involvement is one of the major problems in systemic sclerosis (SSc). Subclinical cardiac involvement has a higher frequency than thought previously. In this study we investigated whether subclinical cardiac involvement can be detected by using echocardiographic strain imaging in SSc patients without pulmonary hypertension. Methods: Echocardiographic examinations were performed to 27 SSc patients and 26 healthy controls. Left ventricular strain parameters were obtained from apical views and average strain value was calculated from these measurements. Results: There were no significant differences between patients and controls regarding two-dimensional (2D), conventional Doppler and tissue Doppler velocity measurements. Strain was reduced in 6 of 12 segments of the left ventricle (LV) and in 1 of 2 segments of the right ventricle (RV). Strain rate (SR) was reduced in 2 of 12 segments of the LV and 1 of 2 segments of the RV in SSc patients as compared to controls (P < 0.05 for all). These involvements did not match any particular coronary artery distribution. More important differences were detected by average strain and SR values of the LV between patients and controls (19.78 ± 3.00% vs 23.41 ± 2.73%, P < 0.001; 2.01 ± 0.41 vs 2.23 ± 0.27/sec, P = 0.026, respectively). Furthermore, carbon monoxide diffusion capacity (DLCO) in scleroderma patients significantly correlated with LV average strain (r = 0.59; P = 0.001). Conclusion: Evaluation of ventricular function by using echocardiographic strain imaging appears to be useful to detect subclinical cardiac involvement in SSc patients with normal standard echocardiographic and tissue Doppler velocity findings. [source] Right Ventricular Function Assessment: Comparison of Geometric and Visual Method to Short-Axis Slice Summation MethodECHOCARDIOGRAPHY, Issue 10 2007Daniel Drake M.D. Background: Short-axis summation (SAS) method applied for right ventricular (RV) volumes and right ventricular ejection fraction (RVEF) measurement with cardiac MRI is time consuming and cumbersome to use. A simplified RVEF measurement is desirable. We compare two such methods, a simplified ellipsoid geometric method (GM) and visual estimate, to the SAS method to determine their accuracy and reproducibility. Methods: Forty patients undergoing cine cardiac MRI scan were enrolled. The images acquired were analyzed by the SAS method, the GM (area and length measurement from two orthogonal planes) and visual estimate. RVEF was calculated using all three methods and RV volumes using the SAS and GM. Bland,Altman analysis was applied to test the agreement between the various measurements. Results: Mean RVEF was 49 ± 12% measured by SAS method, 54 ± 12% by the GM, and 49 ± 11% by visual estimate. There were similar bias and limits of agreement between the visual estimate and the GM compared to SAS. The interobserver variability showed a bias close to zero with limits of agreement within ±10% absolute increments of RVEF in 35 of the patients. The RV end-diastolic volume by GM showed wider limits of agreement. The RV end-systolic volume by GM was underestimated by around 10 ml compared to SAS. Conclusion: Both the visual estimate and the GM had similar bias and limits of agreement when compared to SAS. Though the end-systolic measurement is somewhat underestimated, the geometric method may be useful for serial volume measurements. [source] Two-Dimensional Assessment of Right Ventricular Function: An Echocardiographic,MRI Correlative StudyECHOCARDIOGRAPHY, Issue 5 2007Nagesh S. Anavekar M.D. Background: While echocardiography is used most frequently to assess right ventricular (RV) function in clinical practice, echocardiography is limited in its ability to provide an accurate measure of RV ejection fraction (RVEF). Hence, quantitative estimation of RV function has proven difficult in clinical practice. Objective: We sought to determine which commonly used echocardiographic measures of RV function were most accurate in comparison with an MRI-derived estimate of RVEF. Methods: We analyzed RV function in 36 patients who had cardiac MRI studies and echocardiograms within a 24 hour period. 2D parameters of RV function,right ventricular fractional area change (RVFAC), tricuspid annular motion (TAM), and transverse fractional shortening (TFS) were obtained from the four-chamber view. RV volumes and EFs were derived from volumetric reconstruction based on endocardial tracing of the RV chamber from the short axis images. Echocardiographic assessment of RV function was correlated with MRI findings. Results: RVFAC measured by echocardiography correlated best with MRI-derived RVEF (r = 0.80, P < 0.001). Neither TAM (r = 0.17; P = 0.30) nor TFC (r = 0.12; p< 0.38) were significantly correlated with RVEF. Conclusions: RVFAC is the best of commonly utilized echocardiographic 2D measure of RV function and correlated best with MRI-derived RV ejection fraction. Condensed Abstract: While echocardiography is used most frequently to assess RV function in clinical practice, echocardiography is limited in its ability to provide an accurate measure of RV ejection fraction (RVEF). Using cardiac MRI, RV fractional area change (RVFAC), determined either by MRI or echocardiography, was found to correlate best with MRI-derived RVEF. [source] An Abnormal Right Ventricular Apical Angle is Indicative of Global Right Ventricular ImpairmentECHOCARDIOGRAPHY, Issue 5 2006Angel López-Candales M.D. The presence of right ventricular (RV) dysfunction is an adverse prognostic indicator but current echocardiographic methods have some limitations. RV apical angles in systole and diastole were correlated with known parameters of RV function in patients without pulmonary hypertension (Group 1) and in patients with pulmonary hypertension (Group 2). RV apical angles were significantly smaller in both systole (22 ± 7°) and diastole (33 ± 6°) in Group 1 patients when compared to Group 2 (54 ± 18°, p < 0.0001 and 59 ± 17°, p < 0.0001, respectively). RV apical angles, both in systole and diastole, were strongly correlated with RV end-systolic area (R = 0.89, p < 0.0001) and end-diastolic area (R = 0.81, p < 0.0001), respectively. Similarly, the apical systolic and diastolic angle correlated well with decreased tricuspid annular plane systolic excursion (TAPSE, R =,0.76 and R =,0.73, p < 0.001) as well as with decreased RV fractional area change (R =,0.81 and R =,0.77, p < 0.001). Therefore, we conclude that this new measurement of RV apical angle is simple and useful to quantify RV apical structural and functional abnormalities that are well correlated with global RV impairment in patients with chronic pulmonary hypertension. [source] Hepatopulmonary Syndrome and Right Ventricular Diastolic Functions: An Echocardiographic ExaminationECHOCARDIOGRAPHY, Issue 4 2006Aziz Karabulut M.D. Aim: Liver functions are affected in the course of cardiac diseases, and similarly, liver diseases affect cardiac functions. Many studies in the literature have shown that left ventricular systolic and/or diastolic dysfunction may develop during chronic liver disease. However, there are limited studies investigating right ventricular functions during chronic liver diseases. Methods: A total of 84 patients who had no systolic and/or diastolic dysfunction in the left ventricle (LV) were evaluated; 46 patients with liver cirrhosis; 10 (21.74%) cirrhotic patients with hepatopulmonary syndrome (HPS) (group 1), 36 (78.26) cirrhotic patients without HPS (group 2), and 38 healthy individuals were treated as control. Results: Right ventricular diastolic dysfunction was determined in all patients of group 1 (100%), 26 of group 2 (72.22 %), and 4 of the controls (10.52%) (P < 0.05). Tricuspid deceleration time (dt) was significantly different between the groups (P < 0.05). In addition, right atrium (RA) diameters, right ventricle (RV) diameters, and RV wall thickness were significantly different between the groups (P < 0.05). Pulmonary artery pressure (P < 0.05) and pulmonary vascular resistance (P < 0.05) were also seen to be higher in group 1 than those in group 2 and control group. Conclusions: Right ventricular diastolic dysfunction rate is high in chronic liver diseases. In the presence of HPS, right ventricular diastolic dysfunction is more remarkable in patients than those without HPS. Right ventricular diastolic dysfunction may result in dilatation and hypertrophy in the right heart. [source] Correlation between Right Ventricular Indices and Clinical Improvement in Epoprostenol Treated Pulmonary Hypertension PatientsECHOCARDIOGRAPHY, Issue 5 2005Jayant Nath M.D. The aim of this study was to evaluate which parameter of right ventricular (RV) echocardiographic best mirrors the clinical status of patients with pulmonary arterial hypertension. Patients with pulmonary arterial hypertension on epoprostenol therapy were identified via hospital registry. Twenty patients, (16 females, 4 males) were included in the study, 9 with primary pulmonary hypertension and 11 with other diseases. Echocardiograms before therapy and at 22.7 (±9.3) months into therapy were compared. The right ventricular myocardial performance index (RVMPI) was measured as the sum of the isometric contraction time and the isometric relaxation time divided by right ventricular ejection time. Other measures included peak tricuspid regurgitation jet velocity (TRV), pulmonary artery systolic pressure (PASP), pulmonary valve velocity time integral (PVVTI), PASP/PVVTI (as an index of total pulmonary resistance) and symptoms by New York Heart Association (NYHA) functional class. Echo parameters of right ventricular function were analyzed in patients, before and during therapy. There was significant improvement of NYHA class in patients following epoprostenol therapy (P < 0.0001). Peak tricuspid regurgitant jet velocity (pre 4.2 ± 0.6 m/sec, post 3.8 ± 0.7 m/sec, P = 0.02) and PASP/PVVTI (pre 6.7 ± 3.3 mmHg/m per second, post 4.8 ± 2.2 mmHg/m per second, P < 0.0001) were significantly improved during treatment. RVMPI did not improve (pre 0.6 ± 0.3, post 0.6 ± 0.3, P = 0.54). Changes in NYHA class did not correlate with changes in RVMPI (P = 0.33) or changes in PASP/PVVTI (P = 0.58). Despite significant improvements in TRV, PASP/PVVTI, and NYHA class, there was no significant change in RVMPI on epoprostenol therapy. Changes in right ventricular indices were not correlated with changes in NYHA class. [source] Noncompaction of the Ventricular Myocardium: Report of Two Cases With Bicuspid Aortic Valve Demonstrating Poor Prognosis and With Prominent Right Ventricular InvolvementECHOCARDIOGRAPHY, Issue 4 2003Yuksel Cavusoglu Noncompaction of the ventricular myocardium is a rare, unclassified cardiomyopathy due to an arrest of myocardial morphogenesis. The characteristic echocardiographic findings consist of multiple, prominent myocardial trabeculations and deep intertrabecular spaces communicating with the left ventricular (LV) cavity. The disease typically involves the LV myocardium, but right ventricular (RV) involvement is not uncommon. The clinical manifestations include heart failure (HF) signs, ventricular arrhythmias and cardioembolic events. Noncompacted myocardium may occur as an isolated cardiac lesion, as well as it can be in association with congenital anomalies. We describe two illustrative cases of noncompaction of the ventricular myocardium, a 19-year-old male with bicuspid aortic valve and progressive worsening of HF, and a 61-year-old male with marked RV involvement in addition to LV apical involvement, both with the typical clinical and echocardiographic features of the disease. (ECHOCARDIOGRAPHY, Volume 20, May 2003) [source] Echocardiographic Features of Patients With Heart Failure Who May Benefit From Biventricular PacingECHOCARDIOGRAPHY, Issue 3 2003Amgad N. Makaryus Background: Recent studies suggest that cardiac resynchronization therapy through biventricular pacing (BVP) may be a promising new treatment for patients with advanced congestive heart failure (CHF). This method involves implantation of pacer leads into the right atrium (RA), right ventricle (RV), and coronary sinus (CS) in patients with ventricular dyssynchrony as evidenced by a bundle branch block pattern on electrocardiogram (ECG). Clinical trials are enrolling stable patients with ejection fractions (EF) , 35%, left ventricular end-diastolic diameters (LVIDd) , 54 mm, and QRS duration ,140 msec. We compared echocardiography features of these patients (group 1) with other patients with EF , 35%, LVIDd , 54 mm, and QRS < 140 msec (group 2 = presumably no dyssynchrony). Methods: Nine hundred fifty-one patients with CHF, LVID 54 mm, EF 35% by echocardiography were retrospectively evaluated. One hundred forty-five patients remained after those with primary valvular disease, prior pacing systems, or chronic atrial arrhythmias were excluded. From this group of 145 patients, a subset of 50 randomly selected patients were further studied (25 patients [7 females, 18 males] from group 1, and 25 patients [7 females, 18 males] from group 2). Mean age group 1 = 75 years old, mean age group 2 = 67 years old. Mean QRS group 1 = 161 msec, mean QRS group 2 = 110 msec. Each group was compared for presence of paradoxical septal motion, atrial and ventricular chamber sizes, LV mass, LVEF, and RV systolic function. Results: Of the initial group of 951 patients, 145 (15%) met inclusion criteria. In the substudy, 20/25 (80%) of group l and 7/25 (28%) of group 2 subjects had paradoxical septal motion on echo (Fisher's exact test, P = 0.0005). The t-tests performed on the other echocardiography variables demonstrated no differences in chamber size, function, or LV mass. Conclusions: Cardiac resynchronization therapy with BVP appears to target a relatively small population of our advanced CHF patients (15% or less). Although increasing QRS duration on ECG is associated with more frequent paradoxical septal motion on echo, it is not entirely predictive. Paradoxical septal motion on echo may therefore be more sensitive at identifying patients who respond to BVP. Further prospective studies are needed. (ECHOCARDIOGRAPHY, Volume 20, April 2003) [source] Assessment of Acute Right Ventricular Dysfunction Induced by Right Coronary Artery Occlusion Using Echocardiographic Atrioventricular Plane DisplacementECHOCARDIOGRAPHY, Issue 6 2000Alpesh R. Shah M.D. Right ventricular (RV) systolic function analysis by echocardiography has traditionally required RV endocardial border definition with subsequent tracing and is often inaccurate or impossible in technically poor studies. The atrioventricular plane displacement (AVPD) method attempts to use the descent of the tricuspid annular ring, a reflection of the longitudinal shortening of the right ventricle, as a surrogate marker for RV systolic function. We hypothesized that RV ischemia induced during right coronary artery occlusion proximal to the major right ventricular branches would result in severe right ventricular systolic dysfunction detectable by the AVPD method. During this pilot study, seven patients undergoing elective proximal RCA angioplasty had echocardiographic measurement of RV AVPD performed at baseline (i.e., immediately prior to RCA balloon inflation), during the last 30 seconds of first RCA balloon inflation, and at 1 minute after balloon deflation (recovery). Lateral and medial RV AVPD were significantly reduced from baseline values during intracoronary balloon inflation. (Lateral: 2.45 cm ± 0.22 vs 1.77 cm ± 0.13, P < 0.001; medial: 1.46 cm ± 0.37 vs 1.28 cm ± 0.32, P < 0.05). Additionally, lateral and medial RV AVPD significantly returned towards baseline values during recovery. (Lateral: 2.39 cm ± 0.20, P < 0.001; medial: 1.58 cm ± 0.27, P = 0.01). At baseline, all lateral RV AVPD values were > 2.0 cm, whereas during balloon inflation all were < 2.0 cm. No such clear distinction was found in medial RV AVPD values. Proximal RCA angioplasty is associated with a significant reduction in lateral and medial RV AVPD. Thus RV AVPD may serve as a marker for RV systolic dysfunction. [source] Reliability of Intraoperative Transesophageal Echocardiography During Tetralogy of Fallot RepairECHOCARDIOGRAPHY, Issue 4 2000JAMES J. JOYCE M.D. There is limited information available concerning the accuracy of intraoperative transesophageal echocardiography (TEE) in predicting the extent of residual abnormalities after recovery from surgical repair of tetralogy of Fallot. Therefore, we investigated differences between the results of final postbypass TEE and those of postrecovery (mean, 6 days after surgery) transthoracic echocardiography in a total of 28 consecutive pediatric patients who underwent repair of tetralogy of Fallot with biplane or multiplane TEE. Both postbypass and postrecovery echocardiographic examinations included measurements of the right ventricle (RV)-main pulmonary artery (PA) and the main PA-branch PA peak instantaneous gradients, the degree of pulmonary valvar insufficiency, and color Doppler interrogation of the ventricular septum for residual defects. The RV-main PA gradient did not change significantly: 15 ± 13 vs 18 ± 14 mmHg (postbypass versus postrecovery, mean ± SD). None of the patients had a decrease of , 10 mmHg; and only one patient had an increase of ,: 15 mmHg. There also was no change in the degree of pulmonary insufficiency (3.0 ±1.2 versus 3.1 ± 1.1, using a scale of 0 to 4). Only one of the seven very small (, 2 mm) residual ventricular septal defects was not discovered during postbypass TEE. However, postrecovery transthoracic echocardiography detected significant branch PA stenosis (peak gradient, , 15 mmHg) in five patients (18%) that was not detected during postbypass TEE (P < 0.03). Of the branch PA stenoses that were not detected during TEE, four were left and one was right. Conclusions: Postbypass TEE after tetralogy of Fallot repair reliably predicts residual postrecovery hemodynamic abnormalities, except for branch PA stenosis. [source] An echocardiographic and auscultation study of right heart responses to training in young National Hunt Thoroughbred horsesEQUINE VETERINARY JOURNAL, Issue S36 2006G. LIGHTFOOT Summary Reasons for performing study: There are few data available to determine the effect of training on cardiac valve function. Objectives: To investigate the effect of commercial race training on right ventricular (RV) and tricuspid valve function in an untrained group of National Hunt Thoroughbreds (TB). Material and methods: Cardiac auscultation, guided M-mode echocardiography of the RV, and colour flow Doppler (CFD) tricuspid valve and right atrium were performed in 90 TB horses (age 2,7 years) 1998,2003. Forty horses were examined at least once and 48 horses were examined on at least 2 occasions. Examinations were then classified as: i) before commencement of race training, ii) after cantering exercise had been sustained for a period of 8,12 weeks and iii) at full race fitness. Tricuspid valve regurgitation (TR) murmurs were graded on a 1,6 scale and CFD echocardiography TR signals were graded on a 1,9 scale. Right ventricular internal diameter (RVID) in diastole and systole (RVIDd and RVIDs) was measured by guided M-mode. Associations between continuous RVID and TR measures and explanatory covariates of weight, age, heart rate, yard and stage of training were examined using general linear mixed models with horse-level random effects. Results: On average, RVIDd and RVIDs increased by 0.08 and 0.1 cm, respectively, per year increase in age (P=0.1 and 0.02) and by 0.3 and 0.4 cm, respectively between pre-training and race fitness (P = 0.07 and 0.005). Tricuspid regurgitation score by colour flow Doppler increased by 0.6/year with age (P<0.0001) and by 1.8 between pre-training and race fitness (P< 0.0001). No significant associations were found between any outcomes and weight, heart rate and training yard. Due to the high level of co-linearity between age and training, multivariable models including both terms were not interpretable. Conclusions and clinical relevance: Athletic training of horses exerts independent effects on both severity and prevalence of tricuspid valve incompetence. This effect should therefore be taken into account when examinations are performed. Dimensions of RV increase with age and training in TB horses in a manner that appears to be similar to that of the LV. [source] Does Host Value Influence Female Aggressiveness, Contest Outcome and Fitness Gain in Parasitoids?ETHOLOGY, Issue 4 2007Marlene Goubault Intraspecific competition for resources is common in animals and may lead to physical contests. Contest outcomes and aggressiveness can be influenced by the resource holding potential of contestants but also by their perception of the resource value (RV). Competitors may assess resource quality directly (real RV) but may also estimate it according to their physiological status and their experience of the habitat quality (subjective RV). In this article, we studied contests between females of the solitary parasitoid Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae) when exploiting simultaneously a host, a Delia radicum L. (Diptera: Anthomyiidae) pupa. We tested the effect of factors modifying host value on the occurrence of agonistic behaviours, contest outcomes and host exploitation. The factors tested were: the quality of the previous habitat experienced by females, female egg load, host parasitism status and the stage reached by the owner female in her behavioural oviposition sequence. Females successfully protected their host against intruders during its exploitation, but not after oviposition, and their aggressiveness did not seem to be influenced by their perception of the RV. The fact that the host is subsequently parasitized by the opponent females appears to mainly depend on the host selectiveness of females. [source] Chamber-specific effects of hypokalaemia on ventricular arrhythmogenicity in isolated, perfused guinea-pig heartEXPERIMENTAL PHYSIOLOGY, Issue 4 2009Oleg E. Osadchii Diuretic-induced hypokalaemia has been shown to promote cardiac arrhythmias in hypertensive patients. The present study was designed to determine whether hypokalaemia increases arrhythmic susceptibility of the left ventricle (LV) or the right ventricle (RV), or both. Proarrhythmic effects of hypokalaemic perfusion (2.5 mm K+ for 30 min) were assessed in isolated guinea-pig heart preparations using simultaneous recordings of volume-conducted electrocardiogram and monophasic action potentials from six ventricular epicardial sites. Effective refractory periods, ventricular fibrillation thresholds and inducibility of tachyarrhythmias by programmed electrical stimulation and tachypacing were determined at the LV and the RV epicardial stimulation sites. Hypokalaemia promoted spontaneous ventricular ectopic activity, an effect attributed to non-uniform prolongation of ventricular repolarization resulting in increased RV-to-LV transepicardial dispersion of refractoriness and action potential duration. Furthermore, hypokalaemic perfusion was associated with reduced ventricular fibrillation threshold and increased inducibility of tachyarrhythmias by programmed electrical stimulation and tachypacing as determined at the LV stimulation site. In contrast, the RV stimulation revealed no change in arrhythmic susceptibility of the RV chamber. Consistently, hypokalaemia reduced the LV effective refractory period but had no effect on the RV refractoriness. This change enabled generation of premature propagating responses by extrastimulus application at earlier time points during LV repolarization. Increased prematurity of extrastimulus-evoked propagating responses was associated with exaggerated local inhomogeneities in intraventricular conduction and action potential duration in hypokalaemic LV, thus creating a favourable stage for re-entrant tachyarrhythmias. Taken together, these findings suggest that proarrhythmic effects of hypokalaemia are mostly attributed to increased LV arrhythmogenicity in the guinea-pig heart. [source] Remote myocardium gene expression after 30 and 120 min of ischaemia in the ratEXPERIMENTAL PHYSIOLOGY, Issue 2 2006Miguel S. Guerra The aim of the present study was to investigate how early the onset of ischaemia-induced changes in gene expression is in remote myocardium, and whether these changes would be different for left and right ventricles. Wistar rats (n= 27) were randomly assigned to left coronary artery (LCA) ligation for 30 or 120 min and sham groups. Evans Blue infusion revealed antero-apical left ventricle (LV) and left intraventricular (IV) septal ischaemia (35.5 ± 0.6% of LV mass). LCA ligation induced transient LV systolic dysfunction and sustained biventricular slowing of relaxation. Regarding mRNA levels, type B natriuretic peptide (BNP) was upregulated in the LV at 30 (+370 ± 191%) and 120 min (+221 ± 112%), whilst in the right ventricle (RV) this was only significant at 120 min (+128 ± 39%). Hipoxia-inducible factor 1, and interleukin 6 overexpression positively correlated with BNP. Inducible NO synthase upregulation was present in both ventricles at 120 min (LV, +327 ± 195%; RV, +311 ± 122%), but only in the RV at 30 min (+256 ± 88%). Insulin-like growth factor 1 increased in both ventricles at 30 (RV, +59 ± 18%; LV, +567 ± 192%) and 120 min (RV, +69 ± 33%; LV, +120 ± 24%). Prepro-endothelin-1 was upregulated in the RV at 120 min (+77 ± 25%). Ca2+ -handling proteins were selectively changed in the LV at 120 min (sarcoplasmic reticulum Ca2+ ATPase, 53 ± 7%; phospholamban, +31 ± 4%; Na+,Ca2+ exchanger, 31 ± 6%), while Na+,H+ exchanger was altered only in the RV (,79 ± 5%, 30 min; +155 ± 70%, 120 min). Tumour necrosis factor-, and angiotensin converting enzyme were not significantly altered. A very rapid modulation of remote myocardium gene expression takes place during myocardial ischaemia, involving not only the LV but also the RV. These changes are different in the two ventricles and in the same direction as those observed in heart failure. [source] | ||||||||||||||||||||||||||||||||||||||||