Echocardiographic evaluation and monitoring of right ventricular function and pulmonary artery pressures

Abstract

Right ventricular (RV) dysfunction is common in critically ill patients. It is associated with multiple clinical scenarios frequently encountered by the intensivist, including acute cor pulmonale, acute RV dysfunction of sepsis, and acute RV infarction. In addition, assessment of right-heart function is essential to assess a subject's preload responsiveness since acute cor pulmonale is also associated with respiratory variations in pulse pressure or stroke volume. Finally, the clinical symptoms of tamponade and acute RV failure are very similar. Echocardiography is the best available method to diagnose and monitor right-heart function at the bedside. When evaluating RV dysfunction, we have to evaluate its severity and differentiate impairment in RV contractility from an increased RV afterload. Pulmonary artery pressure (usually systolic pulmonary artery pressure from tricuspid regurgitant flow with continuous Doppler), can be measured, but it can be underestimated in low-flow conditions. Septal dyskinesia is the echocardiographic hallmark of sudden elevations of RV systolic overload. Septal dyskinesia can be assessed qualitatively (observation of paradoxical septal motion) and quantitatively (measurement of the systolic EI). This sign differentiates RV dysfunction, which does not always impair cardiac output, from RV failure. RV diastolic overload is synonymous with RV dilation, which is best assessed semiquantitatively (characterized as normal, moderately, or severely dilated, based on the ratio of RV to left ventricular end-diastolic areas). RV contractility can be assessed by visual inspection or by systolic movement of the tricuspid annulus (time-movement mode or tissue Doppler imaging), but these indices are also affected by left atrial pressure. © 2011 Springer-Verlag Berlin Heidelberg.