Initial experience of a cohort of XXXX with @entity1121 undergoing biventricular pacing.

@entity1 @entity281 @entity3032 @entity1121
BACKGROUND: Dual chamber pacing improves functional status and reduces left ventricular outflow tract gradients in some, but not all @entity1 with @entity1121 ( @entity1121 ) by altering ventricular depolarisation. We investigated the use of biventricular ( @entity3032 ) pacing in symptomatic @entity1 with @entity1121 . METHOD: 8 @entity1 aged 58  7yrs with symptomatic @entity1121 underwent @entity3032 pacing. 5 @entity1 had LVOT gradients >30mmHg. Ventricular electrodes were placed in the right ventricle (RV) and a branch of the coronary sinus. An atrial electrode was inserted to achieve @entity3032 pacing with a short AV delay. The short-term effects of different pacing modalities were assessed using 2-D and Doppler echocardiography. Symptoms and exercise tolerance were assessed after a month of each pacing mode. Long-term follow up data was available for 5 years. RESULTS: Baseline EF was 67  14% and mean QRS duration was 132  26msecs. @entity3032 pacing reduced QRS duration compared to RV pacing (129  46 vs. 205  54msecs, p<0.005). Five of the seven @entity1 had baseline LVOT gradients (mean 67  25mmHg) that decreased to 41  15mm Hg with RV pacing (p<0.01) and 25  15mmHg with @entity3032 pacing (p<0.005). Improvements in exercise time with active pacing occurred in six out of eight @entity1 (75%), three (37.5%) had optimal exercise times with RV pacing and three with @entity3032 pacing. Of the three @entity1 with short term improvements with @entity3032 pacing, one died 4 years post implant, one deteriorated with LV dilatation and one had the system explanted for @entity281 . CONCLUSION: @entity3032 pacing showed short-term beneficial effects in some @entity1 over and above RV pacing alone.
