Table 2.

Echocardiographic parameters associated with an increased risk of malignant ventricular arrhythmias.

Echocardiography	Pathophysiologic Background	Clinical Setting	Information
LVEF	Left ventricular systolic function	ICM NICM Myocarditis ARVC LVNC	Severe LV systolic dysfunction, of any cause, identified by measuring the LVEF, is associated with an increased risk of SCD (LVEF < 35%)
LV GLS/RLS	Measure of LV systolic function (indirect reflector of myocardial fibrosis/scar)	ICM NICM HCM	GLS is associated with SCD, appropriate ICD therapy and VA
Mechanical dispersion	Slow and heterogeneous electrical conduction of the LV myocardium (indirect reflector of myocardial fibrosis/scar)	ICM NICM HCM ARVC	Predictor of VA in patients with moderate and severe LV systolic dysfunction (despite the etiology of LV dysfunction) and in HCM patients. Predictor of VT/VF (in patients with ARVC)
LV wall thickness	Left ventricular hypertrophy	HCM Myocarditis	Independent predictor of SCD
RVEF, RV diameter, regional RV akinesia, dyskinesia or aneurism	RV remodeling and dysfunction	ARVC	Correlated with more frequent sustained ventricular arrhythmias and ICD appropriate shocks

CMR: cardiac magnetic resonance; LV: left ventricular; GLS/RLS: left ventricular global longitudinal strain/regional longitudinal strain; ICD: implantable cardioverter defibrillator; ICM: ischemic cardiomyopathy; NICM: non-ischemic cardiomyopathy; HCM: Hypertrophic cardiomyopathy; ARVC: arrhythmogenic right ventricular cardiomyopathy; LVNC: left ventricular noncompaction; RV: right ventricular; RVEF: right ventricular ejection fraction; SCD: sudden cardiac death.