Resynchronization Therapy (resynchronization + therapy)

Distribution by Scientific Domains

Kinds of Resynchronization Therapy

  • cardiac resynchronization therapy

  • Selected Abstracts

    Heart Failure and Cardiac Resynchronization Therapies: U.S. Experience in the Year 2000

    Leslie A. Saxon M.D.
    Controlled U.S. trials of cardiac resynchronization therapy (CRT) for improvement of heart failure status are in progress. This article provides the current year 2000 status of all clinical trials in the United States evaluating CRT with and without an ICD. [source]

    Statin Use Is Associated With Improved Survival in Patients With Advanced Heart Failure Receiving Resynchronization Therapy

    Andrew D. Sumner MD
    It is unknown whether statin use improves survival in patients with advanced chronic heart failure (HF) receiving cardiac resynchronization therapy (CRT). The authors retrospectively assessed the effect of statin use on survival in patients with advanced chronic HF receiving CRT alone (CRT-P) or CRT with implantable cardioverter-defibrillator therapy (CRT-D) in 1520 patients with advanced chronic HF from the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) trial database. Six hundred three patients (40%) were taking statins at baseline. All-cause mortality was 18% in the statin group and 22% in the no statin group (hazard ratio [HR] 0.85; confidence interval (CI), 0.67,1.07; P=.15). In a multivariable analysis controlling for significant baseline characteristics and use of CRT-P/CRT-D, statin use was associated with a 23% relative risk reduction in mortality (HR, 0.77; CI, 0.61,0.97; P=.03). Statin use is associated with improved survival in patients with advanced chronic HF receiving CRT. No survival benefit was seen in patients receiving statins and optimal pharmacologic therapy without CRT. [source]

    Optimal Left Ventricular Lead Position Predicts Reverse Remodeling and Survival After Cardiac Resynchronization Therapy

    David Tepper MD
    Background., A nonoptimal LV pacing lead position may be a potential cause for nonresponse to CRT. Methods., The site of latest mechanical activation was determined by speckle tracking radial strain analysis and related to the LV lead position on chest x-ray in 244 CRT candidates. Echocardiographic evaluation was performed after 6 months. Long-term follow-up included all-cause mortality and hospitalizations for heart failure. Results., Significant LV reverse remodeling (reduction in LV end-systolic volume from 189±83 mL to 134±71 mL, P<.001) was noted in the group of patients with a concordant LV lead position (n=153, 63%), whereas patients with a discordant lead position showed no significant improvements. In addition, during long-term follow-up (32±16 months), less events (combined for heart failure hospitalizations and death) were reported in patients with a concordant LV lead position. Moreover, a concordant LV lead position appeared to be an independent predictor of hospitalization-free survival after long-term CRT (hazard ratio: 0.22, P=.004). Conclusions., Pacing at the site of latest mechanical activation, as determined by speckle tracking radial strain analysis, resulted in superior echocardiographic response after 6 months of CRT and better prognosis during long-term follow-up. [source]

    Comparison of the Effects of Cardiac Resynchronization Therapy in Patients With Class II vs Class III and IV Heart Failure (From the InSync/InSync ICD Italian Registry)

    Scott Harris DO
    No abstract is available for this article. [source]

    Combined Longitudinal and Radial Dyssynchrony Predicts Ventricular Response After Resynchronization Therapy

    Article first published online: 2 MAY 200
    No abstract is available for this article. [source]

    Brain Natriuretic Peptide Levels and Response to Cardiac Resynchronization Therapy in Heart Failure Patients

    Reynolds M. Delgado MD
    The authors used brain natriuretic peptide (BNP) as a reliable marker to identify nonresponders to cardiac resynchronization therapy (CRT) in patients with advanced heart failure. The study included 70 patients with left ventricular dysfunction (mean ejection fraction, 21±4%) and left bundle branch block (QRS duration, 164±25 milliseconds) treated with CRT. The authors reviewed data on New York Heart Association functional class, baseline ejection fraction, sodium, creatinine, QRS duration, and BNP levels 3 months before and after CRT therapy. The authors compared results of 42 patients who survived (973+192 days) after CRT implantation (responders) to those of 28 patients (nonresponders) who either expired (n=21) or underwent heart transplantation (n=5) or left ventricular assist device implantation (n=2) after an average of 371+220 days. Mean BNP levels after 3 months of CRT decreased in responders from 758±611 pg/mLto 479±451 pg/mL (P=.044), while in nonresponders there was increase in BNP levels from 1191 ±466 pg/mL to 1611 ±1583; P=.046. A rise in BNP levels was associated with poor response (death or need for transplantation or left ventricular assist device and impaired long-term outcome), which makes it a good predictor to identify such patients. [source]

    Contractile Reserve Assessed Using Dobutamine Echocardiography Predicts Left Ventricular Reverse Remodeling after Cardiac Resynchronization Therapy: Prospective Validation in Patients with Left Ventricular Dyssynchrony

    ECHOCARDIOGRAPHY, Issue 6 2010
    F.R.C.P.C., Mario Sénéchal M.D.
    Background: The presence of viable myocardium may predict response to cardiac resynchronization therapy (CRT). The aim of this study is to evaluate in patients with left ventricular (LV) dyssynchrony whether response to CRT is related to myocardial viability in the region of the pacing lead. Methods: Forty-nine consecutive patients with advanced heart failure, LV ejection fraction < 35%, QRS duration > 120 ms and intraventricular asynchronism , 50 ms were included. Dobutamine stress echocardiography was performed within the week before CRT implantation. Resting echocardiography was performed 6 months after CRT implantation. Viability in the region of LV pacing lead was defined as the presence of viability in two contiguous segments. Response to CRT was defined by evidence of reverse LV remodeling (,15% reduction in LV end-systolic volume). Results: Thirty-one patients (63%) were identified as responders at follow-up. The average of viable segments was 5.9 ± 2 in responders and 3.2 ± 3 in nonresponders (P = 0.0003). Viability in the region of the pacing lead had a sensitivity of 94%, a specificity of 67%, a positive predictive value of 83%, and a negative predictive value of 86% for the prediction of response to CRT. Conclusions: In patients with LV dyssynchrony, reverse remodeling after CRT requires viability in the region of the pacing lead. This simple method using echocardiography dobutamine for the evaluation of local viability (i.e., viability in two contiguous segments) may be useful to the clinician in choosing the best LV lead positioning. (Echocardiography 2010;27:668-676) [source]

    Usefulness and Limitation of Dobutamine Stress Echocardiography to Predict Acute Response to Cardiac Resynchronization Therapy

    ECHOCARDIOGRAPHY, Issue 1 2010
    F.R.C.P.C., Mario Sénéchal M.D.
    Background: It has been hypothesized that a long-term response to cardiac resynchronization therapy (CRT) could correlate with myocardial viability in patients with left ventricular (LV) dysfunction. Contractile reserve and viability in the region of the pacing lead have not been investigated in regard to acute response after CRT. Methods: Fifty-one consecutive patients with advanced heart failure, LV ejection fraction , 35%, QRS duration > 120 ms, and intraventricular asynchronism , 50 ms were prospectively included. The week before CRT implantation, the presence of viability was evaluated using dobutamine stress echocardiography. Acute responders were defined as a ,15% increase in LV stroke volume. Results: The average of viable segments was 5.8 ± 1.9 in responders and 3.9 ± 3 in nonresponders (P = 0.03). Viability in the region of the pacing lead had an excellent sensitivity (96%), but a low specificity (56%) to predict acute response to CRT. Mitral regurgitation (MR) was reduced in 21 patients (84%) with acute response. The presence of MR was a poor predictor of response (sensibility 93% and specificity 17%). However, combining the presence of MR and viability in the region of the pacing lead yields a sensibility (89%) and a specificity (70%) to predict acute response to CRT. Conclusion: Myocardial viability is an important factor influencing acute hemodynamic response to CRT. In acute responders, significant MR reduction is frequent. The combined presence of MR and viability in the region of the pacing lead predicts acute response to CRT with the best accuracy. (Echocardiography 2010;27:50-57) [source]

    Worsening of Left Ventricular End-Systolic Volume and Mitral Regurgitation without Increase in Left Ventricular Dyssynchrony on Acute Interruption of Cardiac Resynchronization Therapy

    ECHOCARDIOGRAPHY, Issue 7 2009
    Suman S. Kuppahally M.D.
    Background: Responders to cardiac resynchronization therapy (CRT) have greater left ventricular (LV) dyssynchrony than nonresponders prior to CRT. Aim: We conducted this study to see whether the long term responders have more worsening of LV dyssynchrony and LV function on acute interruption of CRT. Materials and Methods: We identified 22 responders and 13 nonresponders who received CRT as per standard criteria for 23.73 ± 7.9 months (median 24.5 months). We assessed the acute change in LV function, mitral regurgitation (MR) and compared LV dyssynchrony in CRT on and off modes. Results: On turning off CRT, there was no significant worsening of LV dyssynchrony in both responders and nonresponders. The dyssynchrony measurements by SPWMD, TDI and 3D echocardiography did not correlate significantly. LVESV increased (p = 0.02) and MR (p = 0.01) worsened in CRT-off mode in responders only without significant change in LVEF or LV dimensions. Discussion and Conclusion: In long-term responders to CRT, there is alteration in the function of remodeled LV with acute interruption of CRT, without significant worsening of LV dyssynchrony. The role of different echocardiographic parameters in the assessment of LV dyssynchrony remains controversial. Even after long-term CRT reversely remodels the LV, the therapy needs to be continued uninterrupted for sustained benefits. [source]

    Limited Response to Cardiac Resynchronization Therapy in Patients with Concomitant Right Ventricular Dysfunction

    Limited Response to CRT in Patients with RVD.,Introduction: Patients with left ventricular dysfunction (LVD) and LV dyssynchrony may respond to cardiac resynchronization therapy (CRT). However, right ventricular dysfunction (RVD) is a predictor of decreased survival in patients with LVD, and its influence on clinical response to CRT is unknown. The purpose of this study was to examine the effect of RVD on the clinical response to CRT. Methods and Results: A retrospective cohort of consecutive patients who underwent implantation of a CRT implantable cardioverter-defibrillator (ICD) were included and deemed to have RVD based on a RV ejection fraction <0.40. A lack of response to CRT was defined as: death, heart transplantation, implantation of an LV assist device, absent improvement in NYHA functional class at 6 months or hospice care. Among 130 patients included (mean age 58 ± 11 years, 68.5% male, 87.7% Caucasian, 51.5% nonischemic cardiomyopathy), 77 (59.2%) had no response to CRT as defined above. Of the nonresponders, 43 (56%) had RVD and 34 (44%) did not have RVD (P = 0.02). After adjustment for age, race, gender, cardiomyopathy type, atrial fibrillation, serum sodium, and severe mitral regurgitation, RVD (adjusted OR = 0.34, 95%CI 0.14,0.82), female gender (adjusted OR = 0.36, 95%CI 0.14,0.95), and serum creatinine (adjusted OR = 0.25, 95%CI 0.09,0.71) were independently associated with decreased odds of response to CRT. There was a significant difference in survival of patients with and without RVD after CRT (log rank P = 0.01). Conclusion: RVD represents a strong predictor of lack of clinical response to CRT in patients with CHF due to LVD and should be considered when prescribing CRT. (J Cardiovasc Electrophysiol, Vol. 21, pp. 431,435, April 2010) [source]

    Effect of Left Ventricular Lead Concordance to the Delayed Contraction Segment on Echocardiographic and Clinical Outcomes after Cardiac Resynchronization Therapy

    Introduction: The optimal left ventricular (LV) pacing site for cardiac resynchronization therapy (CRT) is unclear. The current study aims to explore the clinical significance of LV lead concordance to delayed contraction segment in CRT. Methods and Results: Concordant LV lead position was defined as the lead tip located by fluoroscopy at or immediately adjacent to the LV segment with latest contraction determined by tissue Doppler imaging. Echocardiographic and clinical outcomes among 101 consecutive patients with or without concordant LV lead positions were compared. There was no significant difference in changes in LV volumes and clinical parameters between patients with concordant (n = 46) or nonconcordant (n = 55) LV lead positions at 3 and 6 months. In multivariate analysis, the baseline asynchrony index (,= 1.092, 95% CI: 1.050,1.114; P < 0.001), but not LV lead concordance, was the only independent predictor of LV reverse remodeling. By Cox regression analysis, ischemic etiology, and LV reverse remodeling, but not LV lead concordance, were independent predictors of mortality (,= 2.475, 95% CI: 1.183,5.178; P = 0.016, and ,= 0.272, 95% CI: 0.130,0.567; P < 0.001, respectively), cardiovascular hospitalization (,= 1.551, 95% CI: 1.032,2.333; P = 0.035, and ,= 0.460, 95% CI: 0.298,0.708; P < 0.001, respectively), and heart failure hospitalization (,= 0.486, 95% CI: 0.320,0.738; P = 0.001 for LV reverse remodeling). Conclusion: LV lead concordance to the delayed contraction segment may not be a major determining factor for favorable echocardiographic and clinical outcomes after CRT. [source]

    The Role of Positron Emission Tomography in Evaluation of Alterations in Cardiac Efficiency after Cardiac Resynchronization Therapy

    No abstract is available for this article. [source]

    Response to Cardiac Resynchronization Therapy Predicts Survival in Heart Failure: A Single-Center Experience

    Objective: To determine whether survival after cardiac resynchronization therapy (CRT) is related to improvement in clinical or echocardiographic parameters. Background: In clinical trials, CRT improved symptoms, left ventricular (LV) structure, function, and survival. In clinical practice, response to CRT is highly variable and whether survival benefit is confined to those patients who experience improvement in clinical status or cardiac structure and function is unclear. Methods: This is a single-center study of patients receiving clinically indicated CRT between January 2002 and December 2004. Results: Of 309 patients (age 68 ± 11 years, 83% male) receiving CRT at our institution during the study period, 174 returned for follow-up and 127 had repeat echocardiography. Baseline clinical characteristics and survival were similar among those who did or did not return for follow-up. In paired analyses, New York Heart Association (NYHA) class (,0.56 ± 0.07, p < 0.0001), ejection fraction (EF, 6.3 ± 0.7%, P < 0.0001), LV dimension (,2.7 ± 0.6 mm, P < 0.0001), pulmonary artery systolic pressure (PASP, ,4.6 ± 1.3 mm Hg, P = 0.0007), and MR severity grade (,0.20 ± 0.05, P = 0.0002) improved after CRT. Survival after CRT was associated with decrease in NYHA class (risk ratio [RR]= 0.43, P = 0.0004), increase in EF (RR = 0.94, P = 0.02), and decrease in PASP (RR = 0.96, P = 0.03). Change in EF and NYHA class were correlated (r =,0.46, P < 0.0001) and, adjusting for this covariance, change in NYHA (P = 0.04) but not EF (P = 0.12) was associated with improved survival. Conclusion: Patients who experience improved symptoms, ventricular function, and/or hemodynamics have better survival after CRT. These data enhance understanding of the relationship between CRT clinical response and survival benefit in clinical practice. [source]

    Successful Catheter Ablation of Two Types of Ventricular Tachycardias Triggered by Cardiac Resynchronization Therapy: A Case Report

    We report a case of a patient with nonischemic dilated cardiomyopathy and implantable cardioverter-defibrillator, in whom an upgrade to biventricular pacing triggered multiple episodes of ventricular tachycardias (VTs) of two morphologies. First VT presented as repetitive nonsustained arrhythmia of the same morphology as isolated ectopic beats, suggesting its focal origin. Second VT was reentrant and was triggered by the former ectopy, leading to a therapy from the device. Electroanatomical mapping of the left ventricle revealed relatively small low voltage area in the left ventricular outflow tract and identified both an arrhythmogenic focus as well as critical isthmus for reentrant VT. Radiofrequency catheter ablation successfully abolished both VTs. After the procedure, biventricular pacing was continued without any recurrences during a period of 24 months. The report emphasizes the role of catheter ablation in management of VTs triggered by cardiac resynchronization therapy. [source]

    Left Ventricular Lead Proximity to an Akinetic Segment and Impact on Outcome of Cardiac Resynchronization Therapy

    Background: Previous studies report that the optimal pacing site for cardiac resynchronization therapy (CRT) is along the left ventricular (LV) lateral and postero-lateral (PL) wall. However, little is known regarding whether pacing over an akinetic site impacts the contractile response and long-term outcome from CRT. Methods and Results: A total of 38 patients with ischemic cardiomyopathy were studied for their acute hemodynamic and 12-month clinical response to CRT. The intraindividual percentage change in dP/dt (%,dP/dt), over baseline, was derived from the mitral regurgitation (MR) Doppler profile with CRT on versus off. Two-dimensional echocardiography was used for myocardial segmentation and determinination of akinetic sites. LV lead implant site was determined using angiographic and radiographic data and categorized as being "on" (group 1) or "off" (group 2) an akinetic site. Long-term response was measured as a combined endpoint of hospitalization for heart failure and/or all cause mortality at 12 months. Time to primary endpoint was estimated by the Kaplan-Meier method. Clinical characteristics and acute hemodynamic response was similar in both (group 1 [n = 14]; %,dP/dt 48.8 ± 67.4% vs group 2 [n = 24]; %,dP/dt 32.2 ± 40.1%, P = 0.92). No difference in long-term outcome was observed (P = 0.59). In contrast, lead placement in PL or mid-lateral (ML) positions was associated with a better acute hemodynamic response when compared to antero-lateral (AL) positions (PL, %,dP/dt 45.7 ± 50.7% and ML, %,dP/dt 45.1 ± 58.8% vs AL, %,dP/dt 2.9 ± 30.9%, respectively, P = 0.014). Conclusion: LV lead proximity to an akinetic segment does not impact acute hemodynamic or 12-month clinical response to CRT. [source]

    Acceleration-Dependent Left Bundle Branch Block with Severe Left Ventricular Dyssynchrony Results in Acute Heart Failure: Are There More Patients Who Benefit from Cardiac Resynchronization Therapy?

    Cardiac resynchronization therapy (CRT) has been proposed to improve hemodynamics in patients with heart failure and left bundle branch block (LBBB) by resynchronization of left ventricular (LV) dyssynchrony. The current report concerns a patient with narrow QRS complex without LV dyssynchrony who experienced an acute exacerbation of heart failure following exercise. Careful analysis revealed that an increase of heart rate induced acceleration-dependent LBBB with severe LV dyssynchrony and mitral regurgitation followed by acute heart failure and hemodynamic collapse. CRT prevented these adverse reactions. Accordingly, optimal evaluation for CRT may include testing for LV dyssynchrony during exercise. [source]

    Noninvasive Assessment of Cardiac Resynchronization Therapy for Congestive Heart Failure Using Myocardial Strain and Left Ventricular Peak Power as Parameters of Myocardial Synchrony and Function

    Resynchronization Therapy for Heart Failure.Introduction: Although invasive studies have shown that cardiac resynchronization therapy by biventricular pacing improves left ventricular (LV) function in selected heart failure patients, it is impractical to apply such techniques in the clinical setting. The aim of this study was to assess the acute effects of cardiac resynchronization therapy by noninvasive techniques. Methods and Results: Twenty-two patients enrolled in the InSync trial (age 64 ± 9 years, 18 men and 4 women; all with ejection fraction <35% and QRS >130 msec) were studied 1 to 12 months after pacemaker implantation during pacing, and while ventricular pacing was inhibited. Regional myocardial strains of the interventricular septum, LV free wall, and right ventricular free wall were derived from color Doppler tissue echocardiography. Peak power index was calculated as a product of simultaneously recorded noninvasive blood pressure and pulse-wave (PW) Doppler velocity of the LV outflow tract. The Z ratio (sum of LV ejection and filling times divided by RR interval) and tei index were calculated from PW Doppler data. During pacing, overall regional strain improved (P = 0.01), while the LV strain coefficient of variation decreased from 2.7 ± 2.4 to 1.3 ± 0.7 (P = 0.009). Additionally, peak power index improved from 84 ± 24 to 94 ± 27 cm· mmHg/sec (P = 0.004). The Z ratio increased from 0.71 ± 0.08 to 0.78 ± 0.07 (P = 0.0005), while the tei index decreased from 0.86 ± 0.33 to 0.59 ± 0.16 (P = 0.0002). Conclusion: Using novel noninvasive indices, we demonstrated that cardiac resynchronization therapy improves LV performance. [source]

    Utilization of Defibrillators and Resynchronization Therapy at the Time of Evaluation at a Heart Failure and Cardiac Transplantation Center

    Background: Internal cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT) reduce mortality, but are underutilized in routine clinical practice. The use of these devices in patients at the time of an initial evaluation at an advanced heart failure and cardiac transplantation center is unknown. Methods: We retrospectively analyzed consecutive patients who were enrolled in a database examining parameters of cardiopulmonary exercise testing in chronic heart failure (CHF) patients at the time of an initial outpatient evaluation at a tertiary care center. Rates of ICD and CRT use in eligible patients were determined. Results: Two hundred two patients had an average age of 54 ± 13 years and an average peak oxygen consumption (pVO2) of 12.5 ± 4.5 mL/kg/min. Of 97 patients eligible for an ICD only, 57% had an ICD at the time of evaluation. Sixty-four percent of ICD-eligible male patients had an ICD compared to 36% of ICD-eligible female patients (P = 0.015). Of 105 patients meeting criteria for CRT, 54% had a CRT device. There was no difference between CRT use in eligible male and female patients. Conclusions: ICDs and CRT are underutilized in patients with severe CHF at the time of evaluation at a tertiary care center despite young age, objective functional limitation, and active consideration for advanced CHF therapies. Female patients have lower rates of ICD use than male patients. (PACE 2010; 988,993) [source]

    Long-Term Effects of Upgrading to Biventricular Pacing: Differences with Cardiac Resynchronization Therapy as Primary Indication

    Background: Few studies have assessed the long-term effects of cardiac resynchronization therapy (CRT) in patients with advanced heart failure (HF) and previously right ventricular apical pacing (RVAP). Aims: To assess the clinical and hemodynamic impact of upgrading to biventricular pacing in patients with severe HF and permanent RVAP in comparison with patients who had CRT implantation as initial therapy. Methods and Results: Thirty-nine patients with RVAP, advanced HF (New York Heart Association [NYHA] III,IV), and severe depression of left ventricular ejection fraction (LVEF) were upgraded to biventricular pacing (group A). Mean duration of RVAP before upgrading was 41.8 ± 13.3 months. Clinical and echocardiographic results were compared to those obtained in a group of 43 patients with left bundle branch block and similar clinical characteristics undergoing "primary" CRT (group B). Mean follow-up was 35 ± 10 months in patients of group A and 38 ± 12 months in group B. NYHA class significantly improved in groups A and B. LVEF increased from 0.23 ± 0.07 to 0.36 ± 0.09 (P < 0.001) and from 0.26 ± 0.02 to 0.34 ± 0.10 (P < 0.001), respectively. Hospitalizations were reduced by 81% and 77% (P < 0.001). Similar improvements in echocardiographic signs of ventricular desynchronization were also observed. Conclusion: Patients upgraded to CRT exhibit long-term clinical and hemodynamic benefits that are similar to those observed in patients treated with CRT as initial strategy. (PACE 2010; 841,849) [source]

    Response to Cardiac Resynchronization Therapy in Patients with Heart Failure and Renal Insufficiency

    Background: Renal insufficiency (RI) adversely impacts prognosis in heart failure (HF) patients, partly because renal and cardiac dysfunction are intertwined, yet few cardiac resynchronization therapy (CRT) studies have examined patients with moderate-to-severe RI. Methods: We analyzed 787 CRT-defibrillator (CRT-D) recipients with a glomerular filtration rate (GFR) measured prior to implant. Patients were grouped by GFR (in mL/min/1.73 m2): ,60 (n = 376), 30,59 (n = 347), and <30 (n = 64). Overall survival, changes in left ventricular (LV) ejection fraction and LV end-systolic diameter, and GFR change at 3,6 months were compared among CRT-D groups and with a control cohort (n = 88), also stratified by GFR, in whom LV lead implant was unsuccessful and a standard defibrillator (SD) was placed. All patients met clinical criteria for CRT-D. Results: Among CRT-D recipients, overall survival improved incrementally with higher baseline GFR (for each 10 mL/min/1.73 m2 increase, corrected hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.13,1.30, P < 0.0001). Survival among SD and CRT-D patients within GFR < 30 and GFR , 60 groups was similar, whereas CRT-D recipients with GFR 30,59 had significantly better survival compared to SD counterparts (HR 2.23, 95% CI 1.34,3.70; P = 0.002). This survival benefit was associated with improved renal and cardiac function. CRT recipients with GFR , 60 derived significant echocardiographic benefit but experienced a GFR decline, whereas those with GFR < 30 had no echocardiographic benefit but did improve GFR. Conclusions: CRT may provide the largest survival benefit in HF patients with moderate RI, perhaps by improving GFR and LV function. Severe baseline RI predicts poor survival and limited echocardiographic improvement despite a modest GFR increase, such that CRT may not benefit those with GFR < 30 mL/min/1.73 m2. CRT recipients with normal renal function derive echocardiographic benefit but no overall survival advantage. (PACE 2010; 850,859) [source]

    Cardiac Resynchronization Therapy in Non-Left Bundle Branch Block Morphologies

    Introduction: In select patients with systolic heart failure, cardiac resynchronization therapy (CRT) has been shown to improve quality of life, exercise capacity, ejection fraction (EF), and survival. Little is known about the response to CRT in patients with right bundle branch block (RBBB) or non-specific intraventricular conduction delay (IVCD) compared with traditionally studied patients with left bundle branch block (LBBB). Methods: We assessed 542 consecutive patients presenting for the new implantation of a CRT device. Patients were placed into one of three groups based on the preimplantation electrocardiogram morphology: LBBB, RBBB, or IVCD. Patients with a narrow QRS or paced ventricular rhythm were excluded. The primary endpoint was long-term survival. Secondary endpoints were changes in EF, left ventricular end-diastolic and systolic diameter, mitral regurgitation, and New York Heart Association (NYHA) functional class. Results: Three hundred and thirty-five patients met inclusion criteria of which 204 had LBBB, 38 RBBB, and 93 IVCD. There were 32 deaths in the LBBB group, 10 in the RBBB, and 27 in the IVCD group over a mean follow up of 3.4 ± 1.2 years. In multivariate analysis, no mortality difference amongst the three groups was noted. Patients with LBBB had greater improvements in most echocardiographic endpoints and NYHA functional class than those with IVCD and RBBB. Conclusion: There is no difference in 3-year survival in patients undergoing CRT based on baseline native QRS morphology. Patients with RBBB and IVCD derive less reverse cardiac remodeling and symptomatic benefit from CRT compared with those with a native LBBB. (PACE 2010; 590,595) [source]

    Response to Cardiac Resynchronization Therapy: Is It Time to Expand the Criteria?

    Background: Cardiac resynchronization therapy (CRT) is a promising treatment for a subgroup of patients with advanced congestive heart failure and a prolonged QRS interval. Despite the majority of patients benefiting from CRT, 10,40% of patients do not respond to this treatment and are labeled as nonresponders. Given that there is a lack of consensus on how to define response to CRT, the purpose of this viewpoint is to discuss currently used definitions and their shortcomings, and to provide recommendations as to how an expansion of the criteria for CRT response may be useful to clinicians. Methods and Results: Analysis of the literature and case reports indicates that the majority of established measures of CRT response, including New York Heart Association functional class and echocardiographic, hemodynamic, and neurohormonal parameters, are poor associates of patient-reported symptoms and quality of life. Moreover, the potential moderating role of psychological factors in determining health outcomes after CRT has largely been neglected. Conclusions: It is recommended to routinely assess health status after CRT with a disease-specific questionnaire in standard clinical practice and to examine its determinants, including psychological factors such as personality traits and depression. This may lead to improved (secondary) treatment and prognosis in CHF patients treated with CRT. [source]

    Magnetic Resonance Imaging is Superior to Cardiac Scintigraphy to Identify Nonresponders to Cardiac Resynchronization Therapy

    Background: Left ventricular (LV) postero-lateral scar and total scar burden are factors responsible for a poor response to cardiac resynchronization therapy (CRT). Contrast-enhanced magnetic resonance imaging (CMR) and 99mTc-2-methoxy isobutyl isonitrile single photon emission computed tomography (SPECT) perfusion imaging are widely used to detect myocardial scar tissue; however, their ability to detect regional scars and predict a positive response to CRT has not been fully evaluated. Methods: CMR and SPECT were performed in 17 patients with dilated cardiomyopathy (DCM) and seven patients with ischemic cardiomyopathy (ICM) before CRT. All images were scored, using a 17-segment model. To analyze the LV scar regions by CMR, we assessed the transmural delayed enhancement extent as the transmural score in each segment (0 = no scar, 4 = transmural scar). Similarly, a perfusion defect score was assigned to each segment by SPECT (0 = normal uptake, 4 = defect). Results: By both SPECT and CMR imaging, the total scar score was significantly higher in the ICM than in the DCM group. An LV postero-lateral wall scar region was detected using both imaging modes. By SPECT imaging, the percentage of regional scar score in the LV inferior wall was significantly higher in the DCM than in the ICM group. Conclusions: By SPECT imaging in the DCM group, severe perfusion defects, due to attenuation artifacts, were frequently observed in the LV inferior wall, resulting in the overestimation of scar tissue. CMR identified nonresponders to CRT more reliably than SPECT in patients with DCM. [source]

    Cardiac Resynchronization Therapy in Patients with Mildly Impaired Left Ventricular Function

    Aims: We sought to determine the unknown effects of cardiac resynchronization therapy (CRT) in patients with a left ventricular ejection fraction (LVEF) >35%. Because of its technical limitations, echocardiography (Echo) may underestimate LVEF, compared with cardiovascular magnetic resonance (CMR). Methods: Of 157 patients undergoing CRT (New York Heart Association [NYHA] functional class III or IV, QRS , 120 ms), all of whom had a preimplant Echo-LVEF ,35%, 130 had a CMR-LVEF ,35% (Group A, 19.7 ± 7.0%[mean ± standard deviation]) and 27 had a CMR-LVEF >35% (Group B, 43.6 ± 7.7%). All patients underwent a CMR scan at baseline and a clinical evaluation, including a 6-minute walk test and a quality of life questionnaire, at baseline and after CRT. Results: Both groups derived similar improvements in NYHA functional class (A =,1.3, B =,1.2, [mean]), quality of life scores (A =,21.6, B =,33.0; all P < 0.0001 for changes from baseline), and 6-minute walking distance (A = 64.5, B = 70.1 m; P < 0.001 and P < 0.0001, respectively). Symptomatic response rates (increase by ,1 NYHA classes or 25% 6-minute walking distance) were 79% in group A and 92% in group B. Over a maximum follow-up period of 5.9 years for events, patients in group A were at a higher risk of death from any cause, hospitalization for major cardiovascular events (P = 0.0232), or cardiovascular death (P = 0.0411). There were borderline differences in the risk of death from any cause (P = 0.0664) and cardiovascular death or hospitalization for heart failure (P = 0.0526). Conclusions: This observational study suggests that the benefits of CRT extend to patients with a LVEF > 35%. [source]

    Alleviation of Pulmonary Hypertension by Cardiac Resynchronization Therapy is Associated with Improvement in Central Sleep Apnea

    Background: Recent studies have demonstrated that cardiac resynchronization therapy (CRT) reduces sleep apnea in heart failure (HF); however, the mechanism of benefit remains unclear. Methods: Overnight polysomnography (PSG) was performed in consecutive HF patients who were scheduled for CRT implant. Patients with sleep apnea defined by an apnea-hypopnea index (AHI) of >10/hour were recruited and underwent echocardiogram examination at baseline and 3 months after CRT. Results: Among 37 HF patients screened, 20 patients (54%) had sleep apnea and 15 of them consented for the study. After 3 months of CRT, there was a significant improvement in New York Heart Association functional class (3.1 ± 0.1 vs 2.1 ± 0.1, P < 0.01), quality-of-life (QoL) score (62.9 ± 3.3 vs 56.1 ± 4.5, P = 0.02), left ventricular ejection fraction (LVEF, 28.8 ± 2.5% vs 38.1 ± 2.3%, P < 0.01), and reduction in pulmonary artery systolic pressure (PASP, 41.0 ± 2.7 vs 28.6 ± 2.2 mmHg; P < 0.01) compared with baseline. Repeated PSG after CRT demonstrated a reduction in the duration of arterial oxygen desaturation ,95% (251.2 ± 36.7 vs 141.0 ± 37.1 minutes), AHI (27.5 ± 4.7 vs 18.1 ± 3.0, P = 0.05), and number of central sleep apnea (CSA) (7.8 ± 2.6 vs 3.0 ± 1.3/hour, P = 0.03), but not number of obstructive sleep apnea (OSA, 8.6 ± 3.3 vs 7.2 ± 2.3/hour, P = 0.65) compared to baseline. Percentage change in PASP was significantly correlated with percentage changes in LVEF (r=,0.57, P = 0.04), AHI (r = 0.5, P = 0.05), and number of CSA episodes (r = 0.55, P = 0.02). Conclusions: The results demonstrated that CRT significantly reduces CSA in patients with HF. Importantly, we have noted a decrement of PASP correlated to drop in CSA which maybe one of the mechanisms explaining this observation. Future studies are required to confirm our finding and elucidate other possible mechanisms in this regard. [source]

    When Is It Too Late for Cardiac Resynchronization Therapy?

    First page of article [source]

    Cardiac Resynchronization Therapy in Patients with Atrial Fibrillation: Is Atrial Lead Implantation Necessary?

    No abstract is available for this article. [source]

    Removal of Coronary Sinus Intima by a Guidewire during Cardiac Resynchronization Therapy

    Previously, complications associated with the placement of the left ventricular pacing lead were reported in 1.9,6% of cases. We describe a case with a stripping of venous intima from the coronary sinus by a guidewire during a left ventricular lead implantation. Judging from this case, the firm guidewire and coronary catheter should not be used within the coronary sinus. [source]

    Evidence for Electrical Remodeling of the Native Conduction System with Cardiac Resynchronization Therapy

    Background:Cardiac resynchronization therapy (CRT) improves hemodynamics and decreases heart failure symptoms. However, the potential of CRT to bring about electrical remodeling of the heart has not been investigated. Methods and Results:We studied 25 patients, of whom 17 had a nonischemic cardiomyopathy, and 8 had an ischemic cardiomyopathy; 16 had left bundle branch block (LBBB), 1 right bundle branch block (RBBB), and 8 nonspecific intraventricular conduction delay. During routine device clinic visits, patients with chronic biventricular pacing (>6 months) were reprogrammed to VVI 40 to allow for native conduction to resume. After 5 minutes of native rhythm, a surface electrocardiogram (ECG) was recorded, and then the previous device settings were restored. This ECG was compared to the preimplant ECG. Preimplant mean ejection fraction was 19% (range, 10%,35%), and follow-up mean ejection fraction was 35% (12.5%,65%). Mean time from implant to follow-up ECG was 14 months (range, 6,31). The QRS interval prior to CRT was 155 ± 29 ms, and shortened to 144 ± 31 ms (P = 0.0006), and the QRS axis shifted from ,1 ± 59 to ,26 ± 53 (P = 0.03). There was no significant change in PR or QTc interval, or in heart rate. Conclusion:CRT leads to a decrease in the surface QRS duration, without affecting other surface ECG parameters. The reduced electrical activation time may reflect changes in the specialized conduction system or in intramyocardial impulse transmission. [source]

    Long-Term Survival in Patients Treated with Cardiac Resynchronization Therapy: A 3-Year Follow-Up Study from the InSync/InSync ICD Italian Registry

    Background: Studies reporting the long-term survival of patients treated with cardiac resynchronization therapy (CRT) outside the realm of randomized controlled trials are still lacking. The aim of this study was to quantify the survival of patients treated with CRT in clinical practice and to investigate the long-term effects of CRT on clinical status and echocardiographic parameters. Methods: The study population consisted of 317 consecutive patients with implanted CRT devices from eight Italian University/Teaching Hospitals. The patients were enrolled in a national observational registry and had a minimum follow-up of 2 years. A visit was performed in surviving patients and mortality data were obtained by hospital file review or direct telephone contact. Results: During the study period, 83 (26%) patients died. The rate of all-cause mortality was significantly higher in ischemic than nonischemic patients (14% vs 8%, P = 0.002). Multivariate analysis showed that ischemic etiology (HR 1.72, CI 1.06,2.79; P = 0.028) and New York Heart Association (NYHA) class IV (HR 2.87, CI 1.24,6.64; P = 0.014) were the strongest predictors of all-cause mortality. The effects of CRT persisted at long-term follow-up (for at least 2 years) in terms of NYHA class improvement, increase of left ventricular ejection fraction, decrease of QRS duration (all P = 0.0001), and reduction of left ventricular end-diastolic and end-systolic diameters (P = 0.024 and P = 0.011, respectively). Conclusions: During long-term (3 years) follow-up after CRT, total mortality rate was 10%/year. The outcome of ischemic patients was worse mainly due to a higher rate of death from progressive heart failure. Ischemic etiology along with NYHA class IV was identified as predictors of death. Benefits of CRT in terms of clinical function and echocardiographic parameters persisted at the time of long-term follow-up. [source]