CONTRAST ECHOCARDIOGRAPHY DISPLAYS INCREASED SUBENDOCARDIAL PERFUSIONAFTER NITROGLYCERIN ADMINISTRATION

A mechanism proposed to contribute to the antianginal effect of nitrog lycerin is a redistribution of coronary blood flow to the subendocardi um. Contrast echocardiography combines ultrasound with echogenic contr ast agents to assess regional myocardial perfusion. This study aims to assess the effect of nitroglycerin on myocardial transmural perfusion with contrast echocardiography in humans. Nine patients scheduled for coronary angiography received 300 mu g intracoronary nitroglycerin. C ontrast echocardiographic studies were performed before and immediatel y after the administration of intracoronary nitroglycerin. Videodensit ometric analysis was performed off-line to measure subendocardial and subepicardial opacification. Subendocardial opacification greater than subepicardial opacification increased from six of 13 patients before nitroglycerin administration of 11 of 13 after nitroglycerin administr ation (p < 0.05). Similarly, these observations increased from nine of 13 patients to 13 of 13 after nitroglycerin administration during dia stole (p < 0.05). Contrast echocardiography demonstrates increased sub endocardial perfusion after the administration of nitroglycerin in the se patients.