Objective: To determine the echocardiographic end-systolic ventricular geometry value in evaluating right ventricular systolic pressure (RVSP).
Material and methods: We studied prospectively 68 patients (mean age = 6.0 +/- 5.0 years), submitted to cardiac catheterization for cardiac disorders not involving left ventricular (LV) outflow tract obstruction, within 24 hours after two-dimensional echocardiographic (2D echo) examination. 2D echo evaluation of RVSP was performed using end-systolic LV transverse orthogonal diameters (TDR). The LV transverse orthogonal diameters (antero-posterior and supero-inferior) were measured on a parasternal short-axis image, at the tips of papillary muscles. 2D echo semi-quantitative evaluation of RVSP was tested correlating TDR with hemodynamic RVSP/LV systolic pressure (LVSP) ratio--group 1. We also used regression equation derived from the first 35 patients to quantify RVSP in the last 33 patients--group 2. In these cases, systolic systemic arterial pressure measured by sphygmomanometry was taken as LVSP.
Results: The TDR ranged from 1.0 to 2.1 (mean = 1.5 +/- 0.3) and the RVSP/LVSP ratio from 0.3 to 1.7 (mean = 0.7 +/- 0.4). All patients with RVSP/LVSP greater than or equal to 65% have TDR greater than or equal to 1.3 and when RVSP less than or equal to 35 mmHg we always obtained TDR less than or equal to 1.2. The correlation between 2D echo estimated and catheter measured RVSP shows, for group 1, r = 0.88 and y = 1.1X-0.88 and, for group 2'. r = 0.88.
Conclusion: In the absence of LV systolic obstruction, TDR is a reliable non invasive method in evaluating the RVSP.