Progressive heart failure and ventricular fibrillation are major causes of death in patients with chronic heart failure. Mechanical alternans (pulsus alternans) has been observed in patients with severe congestive heart failure. Visible T wave alternans occasionally is a precursor of ventricular fibrillation. We investigated the occurrence of both cardiac alternans in 94 patients with chronic heart failure. Mean left ventricular ejection fraction (LVEF) of the study population was 35 +/- 10%. Mechanical alternans was detected in left ventricular pressure during diagnostic cardiac catheterization. Only sustained mechanical alternans was included in the study. Visible T wave alternans, not microvolt alternans, was noted on standard surface ECG. Cardiac alternans was examined at rest, during physiologic tachycardia, and during stepwise dobutamine loading (2-4-8 microg/kg/min). Prevalences of mechanical and electrical alternans were 19.1% and 4.4% at rest, 45.5% and 8.0% during physiologic tachycardia, and 62.1% and 9.5% under dobutamine loading. Overall, 70 patients (74.5%) showed mechanical alternans and 10 patients (10.6%) showed T wave alternans. T wave alternans always appeared with large mechanical alternans. Among patients w...Continue Reading
Effect of enalapril on mortality and the development of heart failure in asymptomatic patients with reduced left ventricular ejection fractions
Effect of enalapril on survival in patients with reduced left ventricular ejection fractions and congestive heart failure
Effects of enalapril on mortality in severe congestive heart failure. Results of the Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS)
Premature beats elicit a phase reversal of mechanoelectrical alternans in cat ventricular myocytes. A possible mechanism for reentrant arrhythmias
Electrical and mechanical alternans in canine myocardium in vivo. Dependence on intracellular calcium cycling
Changes in the occurrence of mechanical alternans after long-term beta-blocker therapy in patients with chronic heart failure
Onset heart rate of microvolt-level T-wave alternans provides clinical and prognostic value in nonischemic dilated cardiomyopathy
Mechanical alternans in human idiopathic dilated cardiomyopathy is caused with impaired force-frequency relationship and enhanced poststimulation potentiation
Dobutamine-induced mechanical alternans is a marker of poor prognosis in idiopathic dilated cardiomyopathy
Crescendo in depolarization and repolarization heterogeneity heralds development of ventricular tachycardia in hospitalized patients with decompensated heart failure
Microscopic systolic pressure alternans in human cardiomyopathy: noninvasive evaluation of a novel risk marker and correlation with microvolt T-wave alternans
Comparison of patients with pulmonary arterial hypertension with versus without right-sided mechanical alternans
Prominent J-wave and T-wave alternans associated with mechanical alternans in a patient with takotsubo cardiomyopathy
Enhanced predictive power of quantitative TWA during routine exercise testing in the Finnish Cardiovascular Study
Relative refractoriness of left ventricular contraction underlies human tachycardia-induced mechanical and electrical alternans
Symbolic analysis detects alterations of cardiac autonomic modulation in congestive heart failure rats
Detection and evaluation of ventricular repolarization alternans: an approach to combined ECG, thoracic impedance, and beat-to-beat heart rate variability analysis
Failing Left Ventricles Have an Enhanced Post-Stimulation Potentiation Despite Their Impaired Force Frequency Relationship
Utility of heart rate turbulence and T-wave alternans to assess risk for readmission and cardiac death in hospitalized heart failure patients
Assessing risk for rehospitalization and cardiac death in patients with heart failure: Can the dynamic duo of heart rate turbulence and T-wave alternans help?
Distinct U wave changes in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT)
Mechanistic investigation of Ca2+ alternans in human heart failure and its modulation by fibroblasts
Modulation of Cardiac Alternans by Altered Sarcoplasmic Reticulum Calcium Release: A Simulation Study
Cardiac Transmembrane Ion Channels and Action Potentials: Cellular Physiology and Arrhythmogenic Behavior
Cardiac Conduction System
The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Discover the latest research on the cardiac conduction system here.
Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.
Atrial fibrillation is a common arrhythmia that is associated with substantial morbidity and mortality, particularly due to stroke and thromboembolism. Here is the latest research.