Significant functional MR and TR are seen in a substantial proportion of patients with longstanding AF, despite preserved LVEF. This MR/TR combination predicts poor outcome for AF patients, who may have to be treated more intensively.
Multichannel Holter ECG recording in the third intercostal space is more sensitive and useful for the diagnosis of type 1 Brugada ECG than repeated 12-lead ECGs or multichannel Holter ECG in the standard position.
Introduction: Recently, output-dependent QRS transition was reported to be required to confirm left bundle branch (LBB) capture in LBB area pacing (LBBAP) procedure. This study aimed to evaluate the achievement rate and the learning curve of LBB capture in LBBAP procedure performed with the goal of demonstrating output-dependent QRS transition, and investigate predictors of LBB capture.
Methods and Results:The LBBAP procedure was performed in 126 patients with bradyarrhythmia. LBB capture was defined as a demonstration of output-dependent QRS transition. The following pacing definitions were used for evaluation: (1) LBBAP, which met the previously reported LBBAP criteria, (2) LBB pacing (LBBP), LBB capture was confirmed, and (3) available LBBP, LBB threshold was clinically usable (<3 V at 0.4 ms). The learning curve was evaluated by division into three timeperiods. The achievement rates of LBBAP, LBBP, and available LBBP were 88.1%, 41.2%, and 35.7%, respectively. The achievement rates of all three pacing definitions significantly increased with experience (p < .01), but the achievement rate of available LBBP was still 50% in the third period. As predictors of LBB capture, the interval between LBB-Purkinje potential and QRS onset ≥22 ms had high specificity of 98.3%, while R wave peak time in V6 < 68 ms had insufficient sensitivity of 79% and specificity of 68%.
Conclusion:Even if LBB capture was aimed in LBBAP procedure, it was not easy to achieve, and there was a clear learning curve. Much of LBBAP may be left ventricular septal pacing that does not capture LBB.
Background: Left atrial (LA) dilatation in patients with atrial fibrillation (AF) can induce functional mitral regurgitation (MR) despite a preserved left ventricular ejection fraction (LVEF). The purpose of this study was to investigate the etiology of this functional MR. Methods: We retrospectively examined clinical and echocardiographic data from 5,202 consecutive cases that underwent transthoracic echocardiography. AF appeared in 544 patients, and we selected 159 with AF and LVEF ≥50% after excluding patients with other underlying heart diseases. Results: Significant (moderate or greater) degrees of functional MR were seen in 13 (8.2%) patients and were more frequently seen in patients with an AF duration of > 10 years than in others (27 vs. 4%, p = 0.0057). Multiple regression analysis revealed that both the LA dimension index and the left ventricular (LV) systolic dimension index were independent determinants of the MR grading. Among the mitral morphologic parameters, the mitral annular (MA) dimension index and the hamstringing phenomenon of the posterior mitral leaflet were independent determinants of MR grading. Significant MR was not seen in patients without LA dilatations, but it occurred in 14% of patients with LA dilatation alone and in 55% with both LA and LV dilatations; the MA dimension index increased in this order. Conclusions: The grading of functional MR occurring in patients with AF and preserved LVEF depends on both the LA dimension and the LV systolic dimension. The MR grading also depends on both the MA dilatation and the hamstringing phenomenon of the posterior mitral leaflet.
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