Effect of a Meal on Cardiac Performance in Patients with Coronary Artcry Disease

BACKGROUND: It has been well recognized that exercise tolerance and angina threshold in patients with coronary artery disease (CAD) are reduced after a meal. But precise mechanism leading to the postprandial worsening of angina has yet to be adequately defined. This study was undertaken to determine the effect of a mixed meal on cardiac performance and heart rate variability (HRV) in patients with CAD. METHODS: 24 patients with angina or myocardial infarction were studied. Echocardiographic examination and heart rate variability test were performed in the fasting state and the other 40-60 minutes after a 600-800 kcal mixed meal. RESULTS: In the postprandial state, resting heart rate was significantly increased by 5.2% from 64.8+/-10.69 beats/min to 68.2+/-10.2 beats/min (p<0.01), stroke volume by 8.1% from 59.6+/-17.3 ml to 64.4+/-18.1 ml (p<0.01), cardiac output by 14.2% from 3.8+/-1.06 to 4.3+/-1.21 (p<0.01). E wave and A wave of mitral filling flow and E/A ratio were not significantly different in the fasting and postprandial tests. But DT and IVRT were significantly increased in the postprandial state (p<0.05, p<0.01 respectively). HRV was not different in the fasting and postprandial state. CONCLUSIONS: In patients with CAD, a 600-800 kcal mixed meal significantly increased resting heart rate, stroke volume, cardiac output, DT and IVRT.

Differences in Left and Right Ventricular Function between Different Infarct Sites: An ECG-Gated Blood Pool Study

BACKGROUND: Ventricular function is one of the important prognostic factors in patients with coronary artery disease. Among noninvasive approaches for the evaluation of ventricular performance, radionuclide ventriculo-graphy has shown to be of particular values in the patients with myocardial infarction. We have evaluated ven-tricular function with ECG-gated blood pool scan (GBPS) in patients with myocardial infarction of different locations and compared right and left ventricular functions. METHOD: Left and right ventricular function was assessed with multigated blood pool scan in 49 patients at 2-3 weeks after acute myocardial infarction (anterior infarction=23, inferior infarction=19, and lateral infarction=7). Left ventricular ejection fraction (LVEF), right ventricular ejection fraction (RVEF), maximal emptying rate, maximal filling rate, phase angle and full width at half maximum (FWHM) of phase angles were measured during rest. RESULTS: 1) LVEF was signifi-cantly lower in the patients with anterior myocardial infarction (32.2%) than that of inferior (46.5%, p<0.001) or lateral infarction (45.5%, p<0.05), but not different between inferior and lateral infarction. 2) RVEF was significantly lower in the patients with inferior myocardial infarction (24.6%) than that of anterior (30.5%, p<0.05) or lateral infarction (36.1%, p<0.001), and RVEF of anterior infarction was significantly lower than that of lateral infarction (p<0.05). 3) Phase angle and FWHM of left ventricle and right ventricle phase histogram were not significantly different among the patients groups with different infarct sites. CONCLUSIONS: Ventricular function was differently affected by different infarct sites. Inferior infarction resulted in a greater reduction in right ventricular ejection fraction. In contrast, LVEF was greatly depressed in anterior infarction than in inferior infarction.