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Low Cardiac Output (low + cardiac_output)
Selected AbstractsTricuspid Valve Malfunction and Ventricular Pacemaker Lead: Case Report and Review of the LiteratureECHOCARDIOGRAPHY, Issue 8 2006Said B. Iskandar M.D. Pacemaker implantation can be associated with several complications, including myocardial perforation with or without pericardial effusion, venous thrombosis, vegetations of the tricuspid valve (TV) or pacing lead, and tricuspid regurgitation (TR). The TR is thought to be derived from deformity or perforation of the TV by the pacing lead or secondary to atrioventricular discordance with asynchronous ventricular pacing. Severe TR can be deleterious to the patient because it raises the central venous pressure by increasing the right sided preload. Chronically, the increase in right sided blood volume can result in an increase in the right atrial pressure leading to a decrease in venous return and low cardiac output. Severe TR from leaflet adhesion to the pacemaker lead has not been reported before. With the aging of the population and the expanding use of pacemakers and implantable cardioverter defibrillators (ICD) in clinical practice, this complication may be seen more frequently. We present a patient diagnosed with severe TR, years after his pacemaker implantation. His TR was thought to be caused by adhesion of the tricuspid valve to his pacemaker lead. [source] Central venous oxygen saturation for the diagnosis of low cardiac output in septic shock patientsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2010A. PERNER Background: Simple diagnostic tests are needed to screen septic patients for low cardiac output because intervention is recommended in these patients. We assessed the diagnostic value of central venous oxygen saturation in the superior vena cava (ScvO2) for detecting low cardiac output in patients with septic shock. Methods: We conducted a prospective observational study in three general intensive care units (ICUs) of adult patients with septic shock, who were to have a catheter inserted for thermodilution measurement of cardiac index (CITD). Paired measurements of CITD and central venous oximetry values were obtained when the clinician first measured CITD. Results: We included 56 patients with septic shock and a mean sequential organ failure assessment score of 12 (range 3,20). Baseline CITD was 3.5 l/min/m2 (1.0,6.2) and ScvO2 of 70% (33,87). The best cut-off of ScvO2 for CITD>2.5 l/min/m2 (n=42) was a value ,64% with positive and negative predictive values of 91% (95% confidence interval 79,98) and 91% (59,100), respectively. The diagnostic values were not improved by using instead central venous O2 tension or the difference between arterial and central venous O2 saturation. Conclusions: This prospective, observational study found that a ScvO2 measurement of ,64% indicated CITD>2.5 l/min/m2 in ICU patients with septic shock. [source] Perioperative Ventricular Arrhythmias in Patients Undergoing Partial Left VentriculectomyJOURNAL OF CARDIAC SURGERY, Issue 2 2001Toshimi Ujiie M.D. Background: Although incidence of ventricular arrhythmias after partial left ventriculectomy (PLV) has been reported, there are no studies comparing incidence before and after PLV. Although operative scars may give rise to arrhythmias, improved energetic efficiency after PLV may decrease their incidence. Methods: Pre- and postoperative ventricular arrhythmias were monitored by Holter ECG and analyzed in 17 patients undergoing PLV in Curitiba, Brazil. Results: Although total 24-hour heart beat (THB) increased significantly (p = 0.018), ventricular premature contractions (VPCs) decreased markedly (p = 0.036), excluding one patient dying in low cardiac output (LOS) who had terminal arrhythmias increased multifold. In the remaining 16 patients, VPC pairs were also reduced significantly on the average (p = 0.038). In contrast, ventricular tachycardia (VT; more than three consecutive VPCs) disappeared in five patients, decreased in two patients, and newly occurred in four patients, with five patients showing no change; one of them developed a prolonged VT, successfully reversed by external cardioversion. Conclusions: Despite notable significant increase in THB immediately after PLV, PVC and PVC pairs were significantly decreased in contrast to VT, which disappeared in some patients and newly occurred in other patients, remaining constant on the average. Sustained VT occurring in a patient with all other arrhythmias suppressed may suggest a unique electrophysiological substrate, may justify prophylactic use of amiodarone or an implantable cardioverter-defibrillator, and may underscore the importance of further and extended studies. [source] Does Simultaneous Antegrade and Retrograde Cardioplegia Improve Functional Recovery and Myocardial Homeostasis?JOURNAL OF CARDIAC SURGERY, Issue 5 2000F.E.T.C.S., M. J. Jasinski M.D. Methods: Forty patients who underwent elective coronary artery bypass grafting (CABG) were prospectively assigned to two clinically matched groups and analyzed in respect to cardioplegia protocol. Group I consisted of 24 patients who received continuous retrograde blood cardioplegia; Group II consisted of 16 patients who received simultaneous continuous ante- and retrograde cardioplegia. Hydrogen ion release, carbon dioxide, lactate concentration oxygen content, and oxygen extraction were measured from coronary sinus effluent and from the arterial line before and after cross-clamping of the aorta. Median changes of these parameters were reported. Cardiac output was measured and left and right ventricle stroke works were calculated. Incidence of low cardiac output, ventricular fibrillation, raised cardiac enzymes, and ischemic changes on electrocardiogram (ECG) were noted. Results: In the simultaneous group, oxygen content and oxygen extraction recovered well after cross-clamping. The same parameters did not recover to the same extent in the retrograde group. These changes were notable between groups. Hydrogen ion, carbon dioxide, and lactate releases were comparable between groups. Trend toward better recovery of left ventricle stroke work index was encountered in the simultaneous group. Conclusions: Viability of myocardium measured with oxygen utilization and functional recovery is better preserved with simultaneous antegrade and retrograde cardioplegia. However, there is no difference in anaerobic metabolism markers. Thus simultaneous ante- and retrograde cardioplegia is probably advantageous over retrograde alone. [source] Heart failure: a hemodynamic disorder complicated by maladaptive proliferative responsesJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1 2003A. M. Katz Abstract Heart failure has traditionally been viewed as a hemodynamic syndrome characterized by fluid retention, high venous pressure, and low cardiac output. Over the past decade, however, it has become clear that because of deterioration and progressive dilatation (remodeling) of the diseased heart, this is also a rapidly fatal syndrome. The importance of prognosis came to be appreciated when clinical trials showed that therapy which initially improves such functional abnormalities, as high venous pressure and low cardiac output, often fail to improve survival, and that some drugs which improve hemodynamics worsen long-term prognosis. The latter is true for most vasodilators which, in spite of alleviating the adverse short-term consequences of high afterload, shorten survival. Notable exceptions are ACE inhibitors, whose vasodilator effects do not explain their ability to prolong survival; instead, these drugs slow both deterioration and remodeling of the failing heart. Inotropic agents, while providing immediate relief of symptoms, generally shorten long-term survival, whereas ,-blockers slow deterioration and remodeling, and reduce mortality. Aldosterone antagonists exert beneficial effects on prognosis that are not easily explained by their diuretic effects, but instead can be explained by their ability to inhibit signaling pathways that stimulate maladaptive hypertrophy, remodeling, apoptosis and other deleterious responses that cause deterioration of the failing heart. These and other findings demonstrate that heart failure is more than a hemodynamic disorder; these patients suffer from maladaptive proliferative responses that cause cardiac cell death and progressive dilatation that play a key role in determining the poor progressive in this syndrome. [source] Tezosentan normalizes hepatomesenteric perfusion in a porcine model of cardiac tamponadeACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2009A. ÅNEMAN Background: To investigate endothelin-1 (ET-1)-dependent hepatic and mesenteric vasoconstriction, and oxygen and lactate fluxes in an acute, fixed low cardiac output (CO) state. Methods: Sixteen anesthetized, mechanically ventilated pigs were studied. Cardiac tamponade was established to reduce portal venous blood flow (QPV) to 2/3 of the baseline value. CO, hepatic artery blood flow (QHA), QPV, hepatic laser-Doppler flow (LDF), hepatic venous and portal pressure, and hepatic and mesenteric oxygen and lactate fluxes were measured. Hepatic arterial (RHA), portal (RHP) and mesenteric (Rmes) vascular resistances were calculated. The combined ETA,ETB receptor antagonist tezosentan (RO 61-0612) or normal saline vehicle was infused in the low CO state. Measurements were made at baseline, after 30, 60, 90 min of tamponade, and 30, 60, 90 min following the infusion of tesozentan at 1 mg/kg/h. Results: Tamponade decreased CO, QPV, QHA, LDF, hepatic and mesenteric oxygen delivery, while hepatic and mesenteric oxygen extraction and lactate release increased. RHA, RHP and Rmes all increased. Ninety minutes after tesozentan, QPV, LDF and hepatic and mesenteric oxygen delivery and extraction increased approaching baseline values, but no effect was seen on CO or QHA. Hepatic and mesenteric handling of lactate converted to extraction. RHA, RHP and Rmes returned to baseline values. No changes were observed in these variables among control animals not receiving tesozentan. Conclusion: In a porcine model of acute splanchnic hypoperfusion, unselective ET-1 blockade restored hepatomesenteric perfusion and reversed lactate metabolism. These observations might be relevant when considering liver protection in low CO states. [source] B-type natriuretic peptide is related to cardiac function and prognosis in hospitalized patients with decompensated cirrhosisLIVER INTERNATIONAL, Issue 7 2010Joana Pimenta Abstract Background: B-type natriuretic peptide (BNP) concentrations are high in cirrhosis, possibly related to volume status and cirrhotic cardiomyopathy. The prognostic significance of BNP in cirrhosis is unknown. Aims: We aimed to evaluate (i) the influence of haemodynamic parameters and volaemia, assessed by impedance cardiography (ICG), in BNP levels, (ii) the performance of BNP as a prognostic marker, in a cohort of cirrhotic patients. Methods: Patients consecutively hospitalized with decompensated cirrhosis during 1 year were evaluated. At admission, ICG and BNP measurements were performed in 83 patients (median age 56 years; median Child,Pugh score=10). The 70 patients discharged were followed for the occurrence of death within 6 months. Results: Median BNP levels were 130.3 (65.2,363.3) pg/ml. Independent BNP predictors in multivariate linear regression analysis were cardiac output, age and haemoglobin (R2=36.7%). The 24 patients with cardiac systolic dysfunction, defined by low cardiac output, had higher BNP concentrations than the other patients (230.8 vs 98.5 pg/ml, P=0.003). BNP levels above median were associated with an increased occurrence of death within 6 months of discharge (log rank P=0.023). Cardiac output and BNP were predictors of survival in univariate Cox regression analysis. Only BNP remained independently related to the outcome in multivariate analysis [hazard ratio=2.86 (1.11,7.38), P=0.03]. Conclusions: BNP levels in cirrhosis reflect cardiac systolic function and non-cardiac variables that should be considered in their interpretation. BNP is an independent predictor of medium-term survival in advanced cirrhosis, suggesting its utility in risk stratification of decompensated cirrhotic patients. [source] Anesthesia for free vascularized tissue transferMICROSURGERY, Issue 2 2009Natalia Hagau M.D., Ph.D. Anesthesia may be an important factor in maximizing the success of microsurgery by controlling the hemodynamics and the regional blood flow. The intraanesthetic basic goal is to maintain an optimal blood flow for the vascularized free flap by: increasing the circulatory blood flow, maintaining a normal body temperature to avoid peripheral vasoconstriction, reducing vasoconstriction resulted from pain, anxiety, hyperventilation, or some drugs, treating hypotension caused by extensive sympathetic block and low cardiac output. A hyperdynamic circulation can be obtained by hypervolemic or normovolemic hemodilution and by decrease of systemic vascular resistance. The importance of proper volume replacement has been widely accepted, but the optimal strategy is still open to debate. General anesthesia combined with various types of regional anesthesia is largely preferred for microvascular surgery. Maintenance of homeostasis through avoidance of hyperoxia, hypocapnia, and hypovolemia (all factors that can decrease cardiac output and induce local vasoconstriction) is a well-established perioperative goal. As the ischemia,reperfusion injury could occur, inhalatory anesthetics as sevoflurane (that attenuate the consequences of this process) seem to be the anesthetics of choice. © 2008 Wiley-Liss, Inc. Microsurgery, 2009. [source] Decreased 2,3-Diphosphoglycerate Concentration in Low Cardiac Output Patients and Its Influence on the Determination of In Vivo P50ARTIFICIAL ORGANS, Issue 8 2003Marilde A. Piccioni Abstract:, We investigated whether 2,3-diphosphoglycerate (2,3-DPG) is altered in patients with low cardiac output and the influence of its concentration on the calculation of in vivo P50. Biochemical and blood gas analysis were performed along with the measurement of cardiac output and body temperature in 13 patients submitted to cardiopulmonary bypass surgeries without the use of donor blood. In vivo P50 was calculated using the measured (P50m) and the estimated 2,3-DPG (P50e). 2,3-DPG concentration was lower in these patients when compared to the values obtained in normal volunteers (6.9 ± 2.2 vs. 11.9 ± 2.4 ,mol/gHb). P50m was lower than P50e (21.6 ± 1.1 vs. 30.1 ± 1.2 mm Hg) at all time points. Our data show that in patients with low cardiac output, 2,3-DPG concentration is reduced. Therefore, in these patients, the use of standard values for this variable may introduce an error in the calculation of in vivo P50. [source] Use of mechanical assist during high-risk PCI and STEMI with cardiogenic shock,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue S1 2010Tillmann Cyrus MB Abstract Infarct size may be reduced by left ventricular unloading after ST-segment elevation MI (STEMI) in addition to reperfusion therapy. Likewise, high-risk percutaneous coronary intervention (PCI) may benefit from periprocedural support especially in patients with low cardiac output at baseline or when periprocedural hemodynamic deterioration is anticipated. Traditionally, intraaortic balloon-pumps have been used in acute MI with cardiogenic shock. As this modality has limited hemodynamic benefits, new developments have focused on active hemodynamic assist devices. These devices actively unload the left ventricle increasing cardiac output by 2.5,5 L/min and are increasingly easier to implant and monitor. Thus, interventional cardiologists will be able to offer a safer more effective alternative to an increasing patient population with complex cardiac conditions and high-risk PCI. © 2010 Wiley-Liss, Inc. [source] | ||||||||||