EVALUATION OF RIGHT VENTRICULAR PERFORMANCE IN PATIENTS WITH
POSTOPERATIVE CONGENITAL HEART DISEASES USING DOPPLER TISSUE IMAGING AND
CARDIOPULMONARY BYPASS INDICES
Abstract
The RV is considered “the forgotten side of the heart”; however,
limited studies have focused on its evaluation . The RV helps manage
various cardiovascular diseases. Its function is a strong determinant of
the prognosis for patients with congenital heart defects, ischemic heart
disease, pulmonary arterial hypertension, congestive heart failure, and
cardiomyopathy. Therefore, its function should be assessed accurately.
Although cardiac magnetic resonance imaging remains the gold standard
for the noninvasive measurements of RV size and function, it is
time-consuming, expensive, and sometimes not feasible in everyday
clinical practice. Echocardiography is the first and the only method
used frequently for RV evaluation because of its availability and
cost-effectiveness. The complex anatomy of the RV and its trabeculated
myocardium that impedes clear endocardial border tracing, unfavorable
position within the thoracic cavity, and high dependence on the loading
conditions of traditional RV systolic function indices make the
echocardiographic analysis of the RV somewhat challenging. The RV
primarily helps pump blood coming from the systemic venous system to the
pulmonary trunk. The first parts to contract are the inlet and
trabeculated myocardium, and, after 25–50 ms, the conus contracts. The
RV functions as a high-volume, low-pressure pump; the contraction of
predominantly longitudinal fibers as well as afterload and preload
influence the RV’s performance. In addition, RV systolic synchrony,
atrioventricular synchrony, and ventricular interdependence. A previous
study has reported that 20%–40% of the RV volume outflow and systolic
pressure is caused by the contraction of the left ventricle (LV). RV
dyssynchrony potentially reduces the cardiac output or increases the
filling pressure. Thus, maintaining the sinus rhythm and
atrioventricular synchrony is crucial for the performance of the RV,
particularly in the case of chronic RV failure and acute RV infarction.
The current guidelines for cardiac chamber quantification suggest
sonographers to use multiple acoustic windows to precisely observe the
right heart from various perspectives. Because no single index of
contractility that perfectly describes RV performance exists, various
parameters need to be measured. In the clinical practice, the most
common and feasible indices that can be used to evaluate the RV systolic
function are Doppler tissue imaging, tricuspid annular plane systolic
excursion (TAPSE), derived tricuspid lateral annular systolic velocity
(S′ wave), and fractional area change (FAC).