Magrì Damiano, Piccirillo Gianfranco, Ricotta Agnese, De Cecco Carlo Nicola, Mastromarino Vittoria, Serdoz Andrea, Muscogiuri Giuseppe, Gregori Mario, Casenghi Matteo, Cauti Filippo Maria, Oliviero Giada, Musumeci Maria Beatrice, Maruotti Antonello, Autore Camillo
Department of Clinical and Molecular Medicine, 'Sapienza' University, Rome, Italy.
Cardiology. 2015;131(2):122-9. doi: 10.1159/000377622. Epub 2015 Apr 23.
An increased dispersion of myocardial repolarization represents one of the mechanisms underlying the arrhythmic risk in hypertrophic cardiomyopathy (HCM). We investigated spatial myocardial repolarization dispersion indices in HCM patients with nonsustained ventricular tachycardia (NSVT) and, contextually, their main clinical determinants.
Fifty-two well-matched HCM outpatients were categorized into two groups according to the presence or the absence of NSVT at 24-hour Holter electrocardiogram (ECG) monitoring. Each patient underwent a clinical examination, including Doppler echocardiogram integrated with tissue Doppler imaging, cardiac magnetic resonance, and 12-lead surface ECG to calculate the dispersion for the following intervals: QRS, Q-Tend (QTe), Q-Tpeak, Tpeak-Tend (TpTe), J-Tpeak, and J-Tend.
The NSVT group showed only QTe dispersion and TpTe dispersion values to be significantly higher than their counterparts. NSVT occurrence was independently predicted by late gadolinium enhancement presence (p=0.021) and QTe Bazett dispersion (p=0.030), the latter strongly associated with the myocardial performance index (MPI) obtained at the basal segment of the interventricular septum (p=0.0004).
Our data support QTe dispersion as an easy and noninvasive tool for identifying HCM patients with NSVT propensity. The strong relationship between QTe dispersion and MPI allows us to hypothesize an intriguing link between electrical instability and confined myocardial areas of systodiastolic dysfunction.
心肌复极离散度增加是肥厚型心肌病（HCM）心律失常风险的潜在机制之一。我们研究了非持续性室性心动过速（NSVT）的HCM患者的空间心肌复极离散度指标及其主要临床决定因素。
52例匹配良好的HCM门诊患者根据24小时动态心电图（ECG）监测有无NSVT分为两组。每位患者均接受临床检查，包括结合组织多普勒成像的多普勒超声心动图、心脏磁共振成像和12导联体表心电图，以计算以下间期的离散度：QRS、Q-Tend（QTe）、Q-Tpeak、Tpeak-Tend（TpTe）、J-Tpeak和J-Tend。
NSVT组仅QTe离散度和TpTe离散度值显著高于对照组。钆延迟强化的存在（p=0.021）和QTe Bazett离散度（p=0.030）可独立预测NSVT的发生，后者与室间隔基底段获得的心肌性能指数（MPI）密切相关（p=0.0004）。
我们的数据支持将QTe离散度作为识别有NSVT倾向的HCM患者的一种简单且无创的工具。QTe离散度与MPI之间的密切关系使我们能够推测电不稳定与收缩舒张功能障碍局限心肌区域之间存在有趣的联系。
