Evaluation of pulmonary hypertension by M-mode echocardiography in children with ventricular septal defect

Abstract

The authors evaluated the ratio of the right ventricular preejection period to the right ventricular ejection time (RVPEP/RVET) as a predictor of pulmonary hypertension in 16 children with ventricular septal defects (VSD) (group 1). The children ranged in age from 5 months to 18 years. The RVPEP/RVET was measured at the time of cardiac catheterization by M-mode echocardiography from the pulmonary valve echogram and from a simultaneously displayed pulmonary arterial pressure signal obtained with a microtip, manometric catheter. The RVPEP/RVET measured by both methods was comparable (r = 0.91). The RVPEP/RVET was compared with the pulmonary artery diastolic pressure (PADP) (r = 0.54). The RVPEP/RVET ratio correlated less well with the pulmonary arterial mean pressure and pulmonary vascular resistance. In a second group of 51 children with VSD, echocardiographic measurement of the right ventricular systolic time intervals was performed within 24 hours before cardiac catheterization. The same variables of pulmonary arterial pressure as for group 1 were compared with the RVPEP/RVET ratio, and the results were similar. These data indicate that, although there is a relationship between the RVPEP/RVET and pulmonary hypertension, the ratio alone is not accurate enough to avoid cardiac catheterization in patients considered at risk for pulmonary vascular disease.