Pulmonary venous flow pattern in various grades of mitral regurgitation and the effect of mitral surgery on flows in severe regurgitation

Abstract

OBJECTIVE: Firstly, to describe pulmonary venous flow patterns in various grades of mitral regurgitation and secondly, to determine effect of mitral valve surgery on these flows. DESIGN: Descriptive study for the first objective and open randomised intervention for the second objective. SETTING: Mater Misericordiae Hospital Heart Unit, Nairobi (1996-1997). PATIENTS: Thirty eight consecutive patients referred to the unit with various grades of mitral regurgitation from any cause. INTERVENTION: Sixteen patients with severe mitral valve regurgitation underwent mitral valve surgery. MAIN OUTCOME MEASURES: Peak forward flow systolic velocity and peak forward flow diastolic velocity plus their velocity time integrals (VTI). Atrial contraction peak reverse flow velocity and its VTI. RESULTS: Seventy eight per cent of patients with mild (2+) mitral regurgitation (MR) had normal pulmonary venous flow. All patients with moderate (3+) MR had blunted forward systolic flow. Eighty eight per cent of patients with severe (4+) MR had reversal of the normally forward systolic flow. For the patients who had mitral valve surgery, reversed systolic flow of severe MR converted to blunted flow in 12 out of 14 patients. CONCLUSION: Pulmonary venous flow by Doppler echocardiography has potential of being a useful additional index in the grading of MR.