Pulmonary vein flow pattern in mitral stenosis before and after commissurotomy

Pulmonary vein flow (PVF) pattern was studied with an electromagnetic flowmeter in 15 patients with mitral stenosis. ECG, left atrial and left ventricular pressure were recorded simultaneously. Commissurotomy was performed in 8 patients and prosthetic valve replacement in the others. Measurements were performed before and after the intracardiac procedure. The predominating forward flow occurred in ventricular diastole, in contrast to ventricular systole in normal hearts. A small retrograde PVF was observed in 11/15 patients in early ventricular systole, coinciding with the c-wave in left atrial pressure (LAP). The reversed flow did not exceed 13% and showed no correlation to a slight regurgitation demonstrated at left ventricular angiography. The maximum delay in forward systolic PVF after onset of ventricular systole was 0.10 sec. The PVF pattern remained unchanged after commissurotomy in the majority of patients, even after reduction of the mitral valve gradient to less than 5 mmHg. However, holosystolic reversed PVF occurred in one patient, indicating a severe mitral regurgitation. The method of PVF recording is simple and proved useful for haemodynamic analysis and as a control after mitral valve surgery for evaluating the degree of mitral regurgitation.