BACKGROUND Impaired left ventricular (LV) contraction and relaxation may further promote adverse remodeling and may increase the risk of ventricular arrhythmia (VA) in ischemic cardiomyopathy. We aimed to examine the association of cardiovascular magnetic resonance (CMR)-derived circumferential strain parameters for LV regional systolic function, LV diastolic function and mechanical dispersion with the risk of VA in patients with prior myocardial infarction and primary prevention implantable cardioverter defibrillator (ICD). METHODS Patients with an ischemic cardiomyopathy who underwent CMR prior to primary prevention ICD implantation, were retrospectively identified. LV segmental circumferential strain curves were extracted from short-axis cine CMR. For LV regional strain analysis, the extent of moderately and severely impaired strain (percentage of LV segments with strain between - 10% and - 5% and > - 5%, respectively) were calculated. LV diastolic function was quantified by the early and late diastolic strain rate. Mechanical dispersion was defined as the standard deviation in delay time between each strain curve and the patient-specific reference curve. Cox proportional hazard ratios (HR) (95%CI) were calculated to assess the association between LV strain parameters and appropriate ICD therapy. RESULTS A total of 121 patients (63 ± 11 years, 84% men, LV ejection fraction (LVEF) 27 ± 9%) were included. During a median (interquartile range) follow-up of 47 (27;69) months, 30 (25%) patients received appropriate ICD therapy. The late diastolic strain rate (HR 1.1 (1.0;1.2) per - 0.25 1/s, P = 0.043) and the extent of moderately impaired strain (HR 1.5 (1.0;2.2) per + 10%, P = 0.048) but not the extent of severely impaired strain (HR 0.9 (0.6;1.4) per + 10%, P = 0.685) were associated with appropriate ICD therapy, independent of LVEF, late gadolinium enhancement (LGE) scar border size and acute revascularization. Mechanical dispersion was not related to appropriate ICD therapy (HR 1.1 (0.8;1.6) per + 25 ms, P = 0.464). CONCLUSIONS In an ischemic cardiomyopathy population referred for primary prevention ICD implantation, the extent of moderately impaired strain and late diastolic strain rate were associated with the risk of appropriate ICD therapy, independent of LVEF, scar border size and acute revascularization. These findings suggest that disturbed LV contraction and relaxation may contribute to an increased risk of VA after myocardial infarction.

中文翻译：

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既往有心肌梗死和一级预防性植入式心脏复律除颤器的患者，心血管磁共振衍生的圆周应变参数与室性心律失常的风险和全因死亡率的关联。

背景技术受损的左心室（LV）收缩和舒张可能进一步促进不良重塑，并可能增加缺血性心肌病中室性心律不齐（VA）的风险。我们的目的是检查在先前有心肌梗死和一级预防性植入式心脏复律除颤器（ICD）的患者中，源自心血管磁共振（CMR）的圆周应变参数与LV区域收缩功能，LV舒张功能和机械分散性与VA风险的关系。 。方法回顾性分析在一级预防性ICD植入前接受过CMR的缺血性心肌病患者。从短轴电影CMR中提取LV节段的圆周应变曲线。对于LV区域应变分析，计算了中度和重度损伤的程度（应变分别为-10％和-5％和>-5％的LV段的百分比）。左室舒张功能通过早期和晚期舒张应变率来量化。机械分散被定义为每条应变曲线和患者特定参考曲线之间的延迟时间的标准偏差。计算Cox比例风险比（HR）（95％CI），以评估LV应变参数与适当的ICD治疗之间的关联。结果共纳入121例患者（63±11岁，男性84％，左室射血分数（LVEF）为27±9％）。在47（27; 69）个月的中位（四分位间距）随访中，有30（25％）患者接受了适当的ICD治疗。舒张末期应变率（HR 1.1（1.0; 1.2）per-0.25 1 / s，P = 0。043）和中度受损的程度（HR + 1.5（1.0; 2.2）每+ 10％，P = 0.048）但不是严重受损的程度（HR 0.9（0.6; 1.4）/ + 10％，P = 0.685 ）与适当的ICD治疗相关，独立于LVEF，晚期g增强（LGE）疤痕边界大小和急性血运重建。机械分散与适当的ICD治疗无关（HR + 1.1（0.8; 1.6）每+ 25毫秒，P = 0.464）。结论在被称为一级预防性ICD植入的缺血性心肌病人群中，中度受损的程度和舒张末期晚期应变率与适当的ICD治疗的风险有关，而与LVEF，瘢痕边界大小和急性血运重建无关。