The Arrhythmic Phenotype in Cardiomyopathy

Abstract

In the wide phenotypic spectrum of cardiomyopathies, sudden cardiac death (SCD) has always been the most visible and devastating disease complication. The introduction of implantable cardioverter-defibrillators for SCD prevention by the late 1980s has moved the question from how to whom we should protect from SCD, leaving clinicians with a measure of uncertainty regarding the most reliable option to guide identification of the highest-risk patients. In this review, we will go through all the available evidence in the field of arrhythmic expression and arrhythmic risk stratification in the different phenotypes of cardiomyopathies to provide practical suggestions in daily clinical management.

Keywords: Arrhythmic risk stratification; Cardiomyopathies; Sudden cardiac death.

Fig. 1.

ECG of a 43-year-old male patient with FLNC mutation showing low–voltage QRS complexes in peripheral leads and negative T waves in the inferolateral leads.

Fig. 2.

Modified algorithm for DCM patient selection for ICD implantation based on current ESC guidelines combined with the most recent evidence. ^aDesmosomal mutations, family history of SCD, ECG abnormalities, syncope, NSVT, LGE extension.

Fig. 3.

Acute myocarditis with infarct-like presentation. (A) Extensive myocardial edema of the inferior wall; and (B) nonischemic LGE matching areas of edema. (From Porcari A, De Luca A, Grigoratos C, Biondi F, Faganello G, Vitrella G, Nucifora G, Aquaro GD, Merlo M, Sinagra G. Arrhythmic risk stratification by cardiac magnetic resonance tissue characterization: disclosing the arrhythmic substrate within the heart muscle. Heart Fail Rev. 2020 Jun 20.)

Fig. 4.

Cardiac magnetic resonance imaging of AC with biventricular involvement, showing right ventricular free wall aneurysm, irregular epicardial profile of the left ventricle and extensive fibrofatty replacement. (A) Cine steady-state free precession imaging, 4-chamber view; areas of “India ink” artifact evident. (B) Proton density–weighted black blood imaging, bright areas of the septum and left ventricular wall are evident, consistent with fatty substitution. (C) Late gadolinium enhancement imaging, showing extensive fibrotic areas of both ventricles.

Fig. 5.

Modified algorithm for AC patient selection for ICD implantation based on 2019 expert consensus^, combined with the most recent evidence. EPS, electrophysiology study; SVT, sustained ventricular tachycardia. ^aEstimated risk of major ventricular arrhythmias/y; ^bEspecially if hemodynamically not tolerated.

Fig. 6.

Modified algorithm for HCM patient selection for ICD implantation based on current ESC guidelines combined with the most recent evidence. LA, left atrial; LVOT, left ventricular outflow tract.