A new two-dimensional echocardiographic technique for evaluating right ventricular size and performance in patients with obstructive lung disease

Abstract

To compare two-dimensional (2-D) echocardiographic estimates of right ventricular size and performance to similar determinations from equilibrium radionuclide angiography (RNA) before and after isosorbide dinitrate, we evaluated 19 patients with severe chronic obstructive pulmonary disease. The end-diastolic and end-systolic volumes estimated from subcostal 2-D echocardiographic views of the right ventricle correlated with the RNA end-diastolic and end-systolic counts (r = 0.76 and 0.82, respectively). The 2-D echocardiographic and RNA right ventricular ejection fraction (EF) estimates also correlated (r = 0.80), and the average right ventricular EF measures of 42 +/- 11% and 40 +/- 12%, respectively, did not differ significantly. Nitrate administration produced a significant increase in heart rate (99 +/- 11 to 108 +/- 14 beats/min, p less than 0.001) and a decrease in systolic arterial pressure (139 +/- 23 to 120 +/- 22 mm Hg, p less than 0.001). Nitrates also significantly decreased the average 2-D echocardiographic end-diastolic and end-systolic volumes (22 +/- 16% and 18 +/- 12%, p less than 0.001), as well as RNA end-diastolic and end-systolic counts (33 +/- 17% and 32 +/- 22%, p less than 0.001), but did not significantly decrease the average right ventricular EF values (4 +/- 12% and 4 +/- 24%, respectively). Nevertheless, after isosorbide dinitrate, the 2-D echocardiographic right ventricular end-diastolic and end-systolic volume estimates continued to correlate with the corresponding RNA count measures (r = 0.76 and 0.79, respectively), as did the 2-D echocardiographic and RNA right ventricular EF values (r = 0.75). We conclude that 2-D echocardiographic evaluation of right ventricular size and performance is feasible in selected patients with chronic obstructive pulmonary disease, and that 2-D echocardiographic measures of right ventricular size and performance compare favorably with similar determinations by RNA at rest and after nitrate administration.