Department of Cardiology, University of Michigan Cardiovascular Center, Ann Arbor, Michigan, USA.
J Cardiovasc Electrophysiol. 2010 Sep;21(9):1002-8. doi: 10.1111/j.1540-8167.2010.01771.x.
Premature ventricular complexes (PVCs) occur frequently in patients with heart disease. The sites of origin of PVCs in patients with prior myocardial infarction and the response to catheter ablation have not been systematically assessed.
In 28 consecutive patients (24 men, age 60 ± 10, ejection fraction [EF] 0.37 ± 0.14) with remote myocardial infarction referred for catheter ablation of symptomatic refractory PVCs, the PVCs were mapped by activation mapping or pace mapping using an irrigated-tip catheter in conjunction with an electroanatomic mapping system. The site of origin (SOO) was classified as being within low-voltage (scar) tissue (amplitude ≤1.5 mV) or tissue with preserved voltage (>1.5 mV). The SOO was confined to endocardial scar tissue in 24/28 patients (86%). The SOO was outside of scar in 3 patients and could not be identified in 1 patient. At the SOO, local endocardial activation preceded the PVC by 46 ± 19 ms, and the electrogram amplitude during sinus rhythm was 0.48 ± 0.34 mV. The PVCs were effectively ablated in 25/28 patients (89%), resulting in a decrease in PVC burden on a 24-hour Holter monitor from 15.6 ± 12.3% to 2.4 ± 4.2% (P < 0.001). The SOO most often was confined to scar tissue located in the left ventricular septum and the papillary muscles.
Similar to post-infarction ventricular tachycardia, PVCs after remote myocardial infarction most often originate within scar tissue. Catheter ablation of these PVCs has a high-success rate.
室性期前收缩（PVCs）在心脏病患者中经常发生。既往心肌梗死患者 PVC 的起源部位以及导管消融的反应尚未得到系统评估。
在 28 例连续患者（24 例男性，年龄 60 ± 10 岁，射血分数 [EF] 0.37 ± 0.14）中，进行了导管消融症状性难治性 PVC 的研究，这些患者均有陈旧性心肌梗死，使用带有灌流尖端导管的激活标测或起搏标测，结合电解剖标测系统对 PVC 进行标测。起源部位（SOO）分为低电压（瘢痕）组织（幅度≤1.5 mV）或电压保留组织（>1.5 mV）。28 例患者中有 24 例（86%）SOO 局限于心内膜瘢痕组织内。3 例患者的 SOO 位于瘢痕组织之外，1 例患者无法确定 SOO。在 SOO 处，局部心内膜激动比 PVC 提前 46 ± 19 ms，窦性心律时的电图幅度为 0.48 ± 0.34 mV。28 例患者中有 25 例（89%）有效消融了 PVC，24 小时动态心电图监测的 PVC 负荷从 15.6 ± 12.3%下降到 2.4 ± 4.2%（P < 0.001）。SOO 最常局限于左心室间隔和乳头肌的瘢痕组织。
与梗死后室性心动过速相似，陈旧性心肌梗死后的 PVC 起源于瘢痕组织内。这些 PVC 的导管消融成功率很高。
