Exercise cross-sectional echocardiography in ischemic heart disease.

We performed cross-sectional echocardiograms at rest, during supine bicycle exercise, and after sublingual nitroglycerin administration in 28 patients suspected of having ischemic heart disease. Technically adequate exercise cross-sectional echocardiograms were obtained in 20 patients (71%). Ten patients had new areas of reversible segmental dysynergy, and all 10 had significant stenoses of coronary arteries supplying areas of the heart corresponding to the location of reversible dysynergy. Six of these 10 patients also underwent exercise thallium-201 perfusion scanning, and all six had reversible perfusion defects in the area that demonstrated reversible dysynergy on exercise cross-sectional echocardiography. At least two of the remaining 10 patients who did not have reversible segmental dysynergy on exercise cross-sectional echocardiography probably experienced myocardial ischemia that we did not detect. We conclude that exercise cross-sectional echocardiography is technically difficult but feasible. The mechanical consequences of exercise-induced regional myocardial ischemia can be detected noninvasively by real-time, two-dimensional, cross-sectional echocardiography.

Left ventricular function in patients with chronic obstructive pulmonary disease.

Left ventricular function was assessed in six patients with essentially normal cardiopulmonary function, in five patients with primary myocardial disease, and in 16 patients with chronic obstructive pulmonary disease by determining the response of the ventricle to an increased resistance to ejection. Studies were performed at the time of cardiac catheterization and increased resistance to left ventricular ejection was produced by the intravenous infusion of methoxamine. In the control patients, methoxamine produced an increase in stroke volume index (SVI), in stroke work index (SWI), and stroke power index (SPI), whereas left ventricular end-diastolic pressure (LVEDP) increased only moderately. In contrast SVI, SWI, and SPI fell, whereas LVEDP increased inordinately in the patients with myocardiopathy. The patients with chronic obstructive pulmonary disease responded to the infusion with an increase in SVI, SWI, SPI, and LVEDP comparable to the control patients. Furthermore, in this latter group of patients, a quantitatively similar response was observed in those with essentially normal resting hemodynamics, in those with resting pulmonary hypertension, and in those whose disease had progressed to the stage of right ventricular failure. This study provides no evidence that chronic obstructive pulmonary disease results in chronic impairment of left ventricular function, but on the contrary, has demonstrated that the left ventricle responds normally to an increased pressure load in these patients.