ABSTRACT
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.