Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (F.M.E., K.C.S., J.G., M.J.A., A.M.K., A.J.D., M.M., M.v.Z., V.R.V., R.K., A.T., T.M.M., S.J.A., F.D.-C.M.).
Department of Cardiovascular Medicine, Mayo Clinic, Jacksonville, FL (C.J.M.).
Circ Arrhythm Electrophysiol. 2022 Sep;15(9):e011088. doi: 10.1161/CIRCEP.122.011088. Epub 2022 Sep 8.
Mitral annular disjunction (MAD) has recently been recognized as an arrhythmogenic entity. Data on the electrophysiological substrate as well as the outcomes of catheter ablation of ventricular arrhythmias in patients with MAD is limited.
Forty patients with MAD (mean age 47±15 years; 70% female) underwent catheter ablation for ventricular arrhythmias. Detailed clinical, electrocardiographic, cardiac imaging, and procedural data were collected. Clinical outcomes were compared between patients who had substrate modification in the MAD area and those who did not.
Twenty-three (57.5%) patients had ablation for premature ventricular contractions, 10 (25%) patients for sustained ventricular tachycardia, and 7 (17.5%) patients for premature ventricular contraction-triggered ventricular fibrillation. Mean end-systolic MAD length was 10.58±3.49 mm on transthoracic echocardiography. Seventeen (42.5%) patients had preprocedural cardiac magnetic resonance imaging, and 5 (29%) patients had late gadolinium enhancement. Among the 18 (45%) patients who had abnormal local electrograms (low voltage, long-duration, fractionated, isolated mid-diastolic potentials) during electroanatomical mapping, 10 (25%) patients had abnormal electrograms in the anterolateral mitral annulus and/or MAD area. Substrate modification was performed in 10 (25%) patients. Catheter ablation was acutely successful in 36 (90%) patients (elimination of premature ventricular contraction or noninducibility of ventricular tachycardia). After a median follow-up duration of 54.08 (interquartile range, 10.67-89.79) months, premature ventricular contraction burden decreased from a median of 9.75% (interquartile range, 3.25-14) before the ablation to a median of 4% (interquartile range, 1-7.75) after the ablation (=0.03 [95% CI, 0.055-6.5]). Eight (20.5%) patients had repeat ablation for ventricular arrhythmias. Substrate modification of the MAD was associated with a trend toward lower rates of repeat ablation (0% versus 26.7%; =0.16).
Patients with MAD have a complex arrhythmogenic substrate, and catheter ablation is effective in reducing recurrence of ventricular arrhythmias. Substrate mapping and ablation may be considered in these patients.
二尖瓣环分离（MAD）最近被认为是一种心律失常的实体。关于 MAD 患者的电生理基质以及导管消融治疗室性心律失常的结果的数据有限。
40 名 MAD 患者（平均年龄 47±15 岁；70%为女性）因室性心律失常接受导管消融治疗。收集详细的临床、心电图、心脏成像和程序数据。比较 MAD 区域有基质改变和无基质改变的患者的临床结果。
23 名（57.5%）患者因室性期前收缩而消融，10 名（25%）患者因持续性室性心动过速而消融，7 名（17.5%）患者因室性期前收缩触发的心室颤动而消融。经胸超声心动图显示平均收缩末期 MAD 长度为 10.58±3.49mm。17 名（42.5%）患者有术前心脏磁共振成像，5 名（29%）患者有晚期钆增强。在 18 名（45%）电生理标测时有异常局部电图（低电压、长时程、碎裂、孤立的舒张中期电位）的患者中，10 名（25%）患者在前外侧二尖瓣环和/或 MAD 区域有异常电图。10 名（25%）患者进行了基质改变。36 名（90%）患者导管消融即刻成功（消除室性期前收缩或不能诱发室性心动过速）。在中位随访 54.08 个月（四分位距，10.67-89.79）后，室性期前收缩负荷从消融前的中位数 9.75%（四分位距，3.25-14%）降至消融后的中位数 4%（四分位距，1-7.75%）（=0.03[95%置信区间，0.055-6.5]）。8 名（20.5%）患者因室性心律失常行重复消融。MAD 的基质改变与重复消融的发生率较低有关（0%对 26.7%；=0.16）。
MAD 患者有复杂的致心律失常基质，导管消融可有效减少室性心律失常的复发。这些患者可能需要进行基质标测和消融。
