Mitral valve prolapse secondary to right ventricular enlargement in patients with pulmonary hypertension after toxic rapeseed oil ingestion.

A high incidence of mitral valve prolapse (MVP) has been reported in various entities which produce important right ventricular (RV) enlargement with normal or decreased left ventricular (LV) volume. To evaluate the importance of RV enlargement in the genesis of MVP in these cases, we analyzed the echocardiographic studies from 176 patients with 'Síndrome Tóxico'. These patients underwent M-mode, cross-sectional and pulsed Doppler examination because of the suspicion of having dietary pulmonary hypertension, a complication which occurred in almost 20% of patients with this epidemic poisoning and which showed a course of gradual resolution in most of them. RV size was classified according to the RV/LV maximal short-axis dimension ratio as normal, border-line, moderately enlarged and severely enlarged. MPV was diagnosed according to standard M-mode and cross-sectional echocardiographic criteria. A second echocardiographic examination was obtained in 38 patients 12.5 +/- 5.3 months after the first one. The incidence of MVP was 9.3% in patients with normal RV size (N = 107), 9.5% in patients with border-line RV size (N = 23), 30% in patients with moderate RV enlargement (N = 30) and 56% in patients with severe RV enlargement (N = 16) (P less than 0.001). Fourteen (77%) of the 18 patients with MVP and moderate or severe RV enlargement (N = 16) (P less than 0.001). Fourteen (77%) of the 18 patients with MVP and moderate or severe RV enlargement had holosystolic MVP. At pulsed Doppler examination, no patient showed signs of mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)