Mechanism of hemodynamic improvement by dual-chamber pacing for severe left ventricular dysfunction: An acute Doppler and catheterization hemodynamic study

摘要: Objectives.This study was undertaken to determine the mechanism by which improvement in hemodynamic variables may occur with dual-chamber pacing patients severe left ventricular dysfunction. Background.Dual-chamber has recently been proposed as a therapeutic alternative for relief of symptoms dilated cardiomyopathy. Methods.Fifteen systolic dysfunction were studied acutely during atrioventricular (AV) sequential at various AV intervals (60, 100, 120, 140, 180 and 240 ms) use combined Doppler velocity curves pressures obtained high fidelity manometer-tipped catheters thermodilution cardiac output. Results.Neither output nor mean atrial pressure significantly different when baseline state compared those all patients. The classified into two groups. In group I (eight PR >200 ms on rest 12-lead electrocardiogram), increased optimal interval that (3.0 ± 1.0 vs. 3.9 0.43 liters/min, p ≈ 0.005) because timing mechanical synchrony optimized. addition, end-diastolic duration diastolic filling increased, mitral regurgitation abolished. II (seven who had normal conduction rest), decreased from value withcut change period. Conclusions.Dual-chamber any improve acute selecetd cardiomyopathy, mainly optimization synchrony. Reestablishment also contribute improvement.