Table 4.

Left Ventricular Scars in the Lateral Region With Specific Disease Characteristics

LV Scar	Distribution	Phenotype	Red Flags		Etiologies	Further Investigation
Lateral region	Subepicardial/mid-wall	NDLVC/DCM/ARVC	CLINICAL:	•Family history of SCD	Arrhythmogenic cardiomyopathy	Genetic testing
			ECG:	•Low limb voltage •Fragmented QRS
				•Ventricular arrhythmias with a RBBB morphology of the ectopic QRS
			ECHO:	•Systolic LV dysfunction related to the global extent of LGE
		NDLVC/DCM	CLINICAL:	•Recent influenza-like illness	Myocarditis (including SARS-CoV-2, see above)	Laboratory testsb Endomyocardial biopsyc
			ECG:	•Sinus tachycardia •Nonspecific ST alterations
			ECHO:	•Regional thickening of LV wall (without coronary distribution)
		NDLVC/DCM/HCM	CLINICAL:	•Gait disturbance •Myotonia/muscle weakness •Visual impairment	Neuromuscular disorders	Genetic testing Muscle biopsya
			ECG:	•AV nodal and infra-nodal disease
			ECHO:	•Regional wall motion abnormalities
				•Regional wall thinning or thickening
		HCM	CLINICAL:	•X-linked transmission •Juvenile stroke •Angiokeratomas	Anderson-Fabry disease	Genetic testing for glycosphingolipid metabolism
				•Visual impairment •Neuropathic pain •Renal failure
			ECG:	•Progression of ECG: alterations together with persisting LVH signs
				•Short PR interval •RBBB •Chronotropic incompetence
				•Inferolateral TWI
			ECHO:	•Symmetric LVH •RVH •Thickening of mitral valve
	Subepicardial/transmural	DCM	CLINICAL:	•Origin from endemic countries •Previous flulike illness (chagoma)	Chagas Disease	Testing for parasite specific antibodies
			ECG:	•Normal ECG (2/3 of patients) •Infra-nodal disease
			ECHO:	•Regional wall-motion abnormalities •Apical aneurysms •Mural thrombi
		DCM/HCM	CLINICAL:	•Pulmonary disease •Unexplained brady or tachyarrhythmia	Sarcoidosis	Thoracic FDG-PET imaging
			ECG:	•PR prolongation •Advanced AV blocks •RBBB/LBBB
			ECHO:	•Basal septum thinning •Regional LV thickening
				•RV dysfunction in absence of PH
				•Regional wall motion abnormalities (without coronary distribution)

ARVC = arrhythmogenic right ventricular cardiomyopathy; AV = atrioventricular; DCM = dilated cardiomyopathy; ECG = electrocardiogram; FDG-PET = fluorodeoxyglucose positron emission tomography; HCM = hypertrophic cardiomyopathy; LGE = late gadolinium enhancement; LBBB = left bundle branch block; LVEF = left ventricular ejection fraction; LVH = left ventricular hypertrophy; NDLVC = nondilated left ventricular cardiomyopathy; PH = pulmonary hypertension; RBBB = right bundle branch block; RV = right ventricular; RVH = right ventricular hypertrophy; SAM = systolic anterior motion; SARS-CoV-2 = severe acute respiratory syndrome-coronavirus-2; SCD = sudden cardiac death; STEMI = ST-segment elevation myocardial infarction; TWI = T-wave inversion.

^aIndicated when genetic testing is negative and clinical suspicion remains high.

^bIncluding inflammatory and cardiac markers and rheumatologic screening.

^cIn case of suspected fulminant myocarditis or acute myocarditis with acute heart failure, left ventricular dysfunction, and/or rhythm disorders; setting of immune checkpoint inhibitor therapy; acute myocarditis associated with peripheral eosinophilia.