Background: We hypothesized that the post-operative aorto-mitral angle might relate to the occurrence of post-operative atrial arrhythmia (AA), including atrial fibrillation and atrial tachycardia, after mitral valve repair in patients with mitral regurgitation (MR). The purpose of the present study was to determine the effects of the post-operative aorto-mitral angle on new onset AA after mitral valve repair with mitral annuloplasty for treating MR. Methods: One-hundred seventy-two patients without any history of AA underwent mitral valve repair with mitral annuloplasty in our institution between 2008 and 2017. Patient information, including medical records and echocardiographic data, were retrospectively studied. Results: AA occurred in 15 (8.7%) patients during the follow-up period (median, 35.7 months; range, 0.5-132 months). The patients with AA had a longer cardiopulmonary bypass time and a smaller aorto-mitral angle at post-operative TTE than the others (119 ± 6 degrees vs. 125 ± 10 degrees, P = 0.003). There was no significant difference in the degree of post-operative residual MR or functional MS between the groups. In a multivariate Cox proportional hazards analysis, the longer cardiopulmonary bypass time and the smaller post-operative aorto-mitral angle were independent predictors of the occurrence of AA during the follow-up period (odds ratio per 10 minutes 1.11; 95% CI 1.02-1.22, P = 0.019: odds ratio 0.91; 95% CI 0.85-0.98, P = 0.012). Conclusion: A small aorto-mitral angle at post-operative TTE was a predictor of new onset AA after a mitral valve repair for treating MR.

It has been reported that the prevalence of cases whose leads were located in the right ventricular lateral wall (RVLW), even though we intended to implant the leads in the right ventricular septum (RVS), is not uncommon. Among the cases whose leads were assumed to be implanted in the RVS, we experienced three cases whose leads were confirmed to be located in the RVLW by postoperative CT. We investigated the intra-operative fluoroscopic index common to these three leads. In the left anterior oblique view (LAO), the transverse movement of the lead-tip seemed to be exceptionally large in all cases. To assess this index, we compared to the consecutive twenty leads confirmed to be located in the RVS. The transverse movement of the lead-tip in the RVLW was clearly greater than that in the RVS (12.8±1.7 mm vs. 4.2±0.9 mm). This difference was large enough to be judged visually. Large transverse movement of the lead-tip in LAO may be a new visual fluoroscopic index that predicts anchoring to the RVLW.