[Effects of left bundle branch block on pulmonary vein and transmitral flow].

Doppler evaluation of pulmonary venous flow (PVF) and of mitral flow (MF) can be useful to understand left ventricular function. It is well known that left bundle branch block (LBBB) can influence ventricular function. The aim of the present study was to evaluate the role of LBBB induced by ventricular pacing on cardiac performance. We performed transesophageal echocardiography (TEE) in 10 patients affected by sick sinus syndrome (SSS) treated with a permanent pacemaker (VDD modality). We evaluated PVF and MF and compared the pattern from the same patients in sinus rhythm and during cardiac pacing. We observed an increase in the reversal flow in the pulmonary vein during atrial contraction. The diastolic flow of pulmonary vein increased during cardiac pacing. The MF showed an increase in deceleration time. Our results suggest that LBBB is associated with a reduction in ventricular function. This phenomenon induce a higher contribution of atrial contraction to ventricular function.