Right ventricular size, dynamics and function: Its impact on health and disease

Abstract

Accurate assessment of right ventricular (RV) size and function is challenging due to its complex shape and position. RV dysfunction has prognostic significance independent of left ventricular function in many conditions. The research studies constituted this PhD involved non-invasive evaluation of the RV. The aim of our first study was to determine the effects of age and gender on RV systolic and diastolic function using traditional and newer techniques of stain. We recruited 142 healthy adult volunteers over a wide age range, who had transthoracic echocardiograms (TTE) with RV emphasis. There was a decrease in RV systolic and diastolic strain with age, with a differential reduction in basal and mid segmental strain. Males had lower RV function. We then determined the effect of exercise on RV function and changes in pulmonary artery pressure (PAP) in a healthy cohort ascertain the effects of gender and age. 121 healthy volunteers had resting and post exercise TTE. There was augmentation of RV function with exercise, with decreasing augmentation with increasing age, corresponding to an increase in PAP. Males had greater augmentation, however, this was negated when corrected for workload. Pulmonary hypertension (PHT) is a complication of systemic sclerosis (SSc). Exercise testing may be used to identify at risk patients. We examined 25 SSc patients with no PHT and compared them with 23 patients with PHT and controls. We found lower contractile reserve with lower S-Sr and s'. Despite a normal PAP at rest there was higher exercise PAP indicating early RV dysfunction and pulmonary vascular disease. Finally, we examined RV function in amyloidosis, an infiltrative process. AL amyloidosis patients were divided into those with and without overt cardiac involvement (NCA). NCA patients had reduced RV function as evidenced by decreased global and segmental systolic strain and diastolic strain rate. AL patients with normal LV diastolic function demonstrated early impairment of RV drastic function with impaired RV e'. RV function although challenging is feasible with newer echocardiographic techniques both in health and disease. As the RV pressures are ow at rest, exercise testing is useful for unmasking early dysfunction.