Simultaneous assessment of left ventricular systolic and diastolic dysfunction during pacing-induced ischemia.

Abstract

Both systolic and diastolic dysfunction have been described during pacing-induced ischemia, but the temporal sequence of systolic and diastolic impairment has not been established. Accordingly, 22 patients with coronary artery disease were paced at increasing heart rates and studied with simultaneous hemodynamic monitoring, electrocardiographic recording, and radionuclide ventriculography. In addition, with synchronized left ventricular pressure tracings and radionuclide volume curves, three sequential pressure-volume diagrams were constructed for each patient corresponding to baseline, intermediate, and maximum pacing levels. Eleven patients (group I) demonstrated a nonischemic response to pacing tachycardia without chest pain, significant electrocardiographic changes, or significant rise in left ventricular end-diastolic pressure (LVEDP) in the immediate postpacing period. These patients demonstrated a progressive decrease in LVEDP, end-diastolic volume, and end-systolic volume, no change in cardiac output or left ventricular ejection fraction, and a progressive increase in left ventricular diastolic peak filling rate and the end-systolic pressure-volume ratio. Pressure-volume diagrams shifted progressively leftward and slightly downward, suggesting both an increase in contractility and a mild increase in left ventricular distensibility. The remaining 11 patients (group II) exhibited an ischemic response to pacing tachycardia, with each patient experiencing angina pectoris, demonstrating greater than 1 mm ST segment depression on the electrocardiogram, and exhibiting greater than 5 mm Hg rise in LVEDP immediately after pacing. LVEDP, end-diastolic volume, and end-systolic volume in these patients initially decreased and then subsequently increased during angina, with no change in cardiac output but a decrease in ejection fraction. Left ventricular peak diastolic filling rate and the left ventricular end-systolic pressure-volume ratio both increased at the intermediate pacing rate but fell at maximum pacing. Pressure-volume diagrams for these patients shifted leftward initially, then back to the right, during intermediate and peak pacing levels, often with an upward shift in the diastolic pressure-volume relationship. LVEDP in group 1I was significantly higher than that in group I at the intermediate pacing level with no difference in end-diastolic or endsystolic volumes, suggesting decreased left ventricular distensibility in these patients before the onset of systolic dysfunction at the maximum pacing level. We conclude that an ischemic response to pacing tachycardia involves both systolic and diastolic dysfunction, with diastolic impairment often preceding systolic depression. Circulation 71, No. 5, 889-900, 1985

Correlation Between Late Gadolinium Enhancement and Diastolic Function in Hypertrophic Cardiomyopathy Assessed by Magnetic Resonance Imaging

“…Diastolic dysfunction is a feature of HCM and explained by increased chamber stiffness and impaired LV relaxation, while systolic function usually remains normal to supranormal. 5 Diastolic dysfunction often precedes systolic dysfunction 30 and heart failure dominates the clinical status in the progressive stage. HCM patients with heart failure have dilated ventricular cavities and commonly exhibit transmural scarring in the ventricular septum.…”

Systolic and Diastolic Properties of Univentricular Hearts in Children: Insights from Physiologic Indices That Reflect Calcium Cycling

“…This, however, underscores that in univentricular hearts, HR crit is significantly shifted to the left. At the ultrastructural level, studies on transgenic models of phospholamban overexpression (21) have elegantly shown that when the HR crit is shifted to the left, it indicates impaired Ca 2ϩ uptake by the SR. At the physiologic level, the decrease in HR crit may represent inadequate myocardial perfusion at faster HRs (29).…”

Heart rate and force-frequency effects on diastolic function of the left ventricle in exercising dogs.

“…the inotropic state, suction effects in the ventricle,7,8 and the heart rate. 9 These factors are interrelated and can affect filling dynamics in both early and late diastole. Under resting conditions, increasing heart rate by atrial pacing augments early diastolic filling and shifts the LV diastolic pressure-volume relation downward.9 During exercise, increased heart rate has an important role in increasing the cardiac output.10"'1 Recent studies from this laboratory show that exercise in normal conscious dogs also markedly enhances early diastolic LV filling with a downward shift of the early portion of the LV diastolic pressure-volume curve, the average value of the pressure nadir being negative despite a marked increase in diastolic filling and considerable reduction of the filling time compared with resting conditions."…”