Good Eric, Desjardins Benoit, Jongnarangsin Krit, Oral Hakan, Chugh Aman, Ebinger Matthew, Pelosi Frank, Morady Fred, Bogun Frank
University of Michigan Medical Center, Ann Arbor, Michigan, USA.
Heart Rhythm. 2008 Nov;5(11):1530-7. doi: 10.1016/j.hrthm.2008.08.032. Epub 2008 Sep 3.
The papillary muscles (PAP) have been implicated in arrhythmogenesis, largely based on theoretical considerations and experimental studies. Few clinical studies have described papillary muscle arrhythmias.
This study sought to describe ventricular arrhythmias arising from the left ventricular PAPs in a consecutive series of patients without prior myocardial infarction and to compare these arrhythmias with fascicular arrhythmias.
Nine of 122 consecutive patients (7%) presenting with symptomatic premature ventricular complexes (PVCs) or nonsustained ventricular tachycardia (VT) were found to have a site of origin in the anterolateral or posteromedial left ventricular PAP. Their mean age was 57 +/- 9 years, and the mean ejection fraction was 0.49 +/- 13. Four of 9 patients had idiopathic cardiomyopathy. The PAP involvement was established by intracardiac echocardiography. Eight of the 122 patients (6.5%) had idiopathic VT originating in the left anterior or posterior fascicle, and these patients served as a control group.
Compared with patients with fascicular arrhythmias, the QRS width was significantly greater in patients with PAP arrhythmias (150 +/- 15 ms vs. 127 +/- 11 ms; P = .001). Presystolic Purkinje potentials were identified at all effective ablation sites for fascicular arrhythmias, but in arrhythmias originating from PAPs, more distal Purkinje potentials often were recorded from the Purkinje-myocardial interface located at the PAP. All arrhythmias originating from the PAPs and the fascicles were effectively ablated. Echocardiography before and after radiofrequency ablation did not show new or worsened mitral insufficiency.
The PAPs can give rise to ventricular arrhythmias in normal and structurally abnormal hearts without prior infarcts. Intracardiac echocardiography seems helpful in recognizing and guiding radiofrequency ablation of PAP arrhythmias.
乳头肌（PAP）与心律失常的发生有关，这主要基于理论考量和实验研究。很少有临床研究描述过乳头肌心律失常。
本研究旨在描述一系列无既往心肌梗死患者中源自左心室乳头肌的室性心律失常，并将这些心律失常与束支性心律失常进行比较。
在连续122例出现有症状室性早搏（PVC）或非持续性室性心动过速（VT）的患者中，9例（7%）被发现起源于左心室前外侧或后内侧乳头肌。他们的平均年龄为57±9岁，平均射血分数为0.49±13。9例患者中有4例患有特发性心肌病。通过心腔内超声心动图确定乳头肌受累情况。122例患者中有8例（6.5%）患有起源于左前或后束支的特发性室性心动过速，这些患者作为对照组。
与束支性心律失常患者相比，乳头肌心律失常患者的QRS波宽度明显更宽（150±15毫秒对127±11毫秒；P = 0.001）。在所有有效的束支性心律失常消融部位均识别出收缩前期浦肯野电位，但在起源于乳头肌的心律失常中，常在位于乳头肌的浦肯野 - 心肌界面记录到更远端的浦肯野电位。所有起源于乳头肌和束支的心律失常均被有效消融。射频消融前后的超声心动图未显示新的或加重的二尖瓣反流。
乳头肌可在无既往梗死的正常和结构异常心脏中引发室性心律失常。心腔内超声心动图似乎有助于识别和指导乳头肌心律失常的射频消融。
