Table 2.

Differential diagnosis between ALVC and DCM

	ALVC	DCM
Predominant genetic background	Mutations of genes encoding for desmosomal proteins, phospholamban and filamin C.	Mutations of genes encoding for cytoskeleton, muscular sarcomere and nuclear envelope proteins.
Main clinical manifestations	Palpitations, syncope and cardiac arrest.	Heart failure and cardiac arrest.
ECG abnormalities	Low QRS voltages in limb leads; negative T-waves in (infero-)lateral leads.	Left ventricular hypertrophy with a strain pattern of ST segment; LBBB.
Echocardiography and CMR imaging features	Non-dilated and hypokinetic LV with a large amount of non-ischaemic (subepicardial) LGE (inferolateral LV wall). Regional wall motion abnormalities (common). Systolic LV dysfunction related to the global extent of LGE.	Dilated and hypokinetic LV with no or patchy non-ischaemic (mid-myocardial) LGE (septum). Regional wall motion abnormalities (uncommon). Systolic LV dysfunction unrelated to the global extent of LGE.
Histopathological features	Fibrofatty myocardial replacement.	Non-specific myocardial abnormalities±fibrosis.
Types of ventricular arrhythmias	PVBs, NSVT and monomorphic sustained VT (RBBB pattern; both LBBB and RBBB patterns in biventricular form); VF.	PVBs and NSVT (RBBB pattern); uncommon sustained VT; VF.
Mechanism of VT	Scar-related re-entry.	Scar-related or functional re-entry (branch to branch re-entry).
Most common site of VT origin	Subepicardial inferolateral LV free wall.	Intramural septum.

ALVC, arrhythmogenic left ventricular cardiomyopathy; CMR, cardiac magnetic resonance; DCM, dilated cardiomyopathy; LBBB, left bundle branch block; LGE, late gadolinium enhancement; LV, left ventricle; NSVT, non sustained ventricular tachycardia; PVBs, premature ventricular beats; RBBB, right bundle branch block; VF, ventricular fibrillation; VT, ventricular tachycardia.