Noninvasive evaluation of right ventricular function

Abstract

Numerous technologic advances have greatly facilitated the noninvasive analysis of right ventricular function. Nevertheless, important clues continue to be available to the astute clinician by physical examination. The chest x-ray is of rather limited utility. The electrocardiogram can show evidence of right atrial enlargement or right ventricular hypertrophy. Unfortunately, both sensitivity and specificity are deficient. Echocardiography is a widely available and potentially very accurate source of information concerning right ventricular dysfunction. Careful temporal analysis of the M-mode echocardiogram can give information beyond chamber size and wall thickness. Two-dimensional echocardiography allows more accurate determination of chamber size and wall thickness and also permits analysis of segmental wall motion and chamber contour. Doppler echocardiography allows measurement of pressure differences and flow kinetics. Preliminary data indicate that one can accurately assess pulmonary artery pressure and possibly right ventricular diastolic function. Color-flow mapping allows for accurate determination of valvular regurgitation and enhances the accuracy of standard Doppler echocardiographic techniques. Radionuclide analysis of the right ventricle by blood-pool imaging allows accurate determination of ejection fraction and wall motion. In addition, it may be possible to estimate pulmonary artery pressure. Use of short-acting radionuclides allows for serial imaging of the right ventricle after pharmacologic intervention or exercise. Perfusion scanning can show evidence of exercise-induced ischemia, although applicability to the right ventricle is somewhat limited. Avid scanning allows localizing of myocardial injury to the right ventricle. CT scanning of the heart is of limited clinical utility, because cardiac motion occurs too rapidly for accurate imaging. The advent of the cine-CT may overcome this problem and allow evaluation of right ventricular volumes and wall motion. Digital subtraction imaging allows for accurate video densitometric calculation of ejection fractions, but offers no advantage over other currently available techniques. Magnetic resonance imaging may prove to be the methodology of choice for analysis of right ventricular function, because it can give accurate measurement of right ventricular wall motion, ejection fraction, and (similar to Doppler flow studies) some indication of flow within the right-sided chambers. It will soon be possible to generate information concerning the biochemical content of the right ventricular myocardium, perhaps providing early evidence of hypertrophy or myopathy.(ABSTRACT TRUNCATED AT 400 WORDS)