Left-dominant arrhythmogenic cardiomyopathy: an under-recognized clinical entity.
OBJECTIVE
We sought to investigate the clinical-genetic profile of left-dominant arrhythmogenic cardiomyopathy (LDAC).


BACKGROUND
In the absence of coronary disease and left ventricular (LV) systolic dysfunction, lateral T-wave inversion and arrhythmia of LV origin are often considered benign. Similarly, chest pain with enzyme release might be attributed to viral myocarditis. We hypothesized that these abnormalities might be manifestations of the "left-dominant" subtype of arrhythmogenic right ventricular cardiomyopathy.


METHODS
The 42-patient cohort was established through clinical evaluation of individuals with unexplained (infero)lateral T-wave inversion, arrhythmia of LV origin, and/or proven LDAC/idiopathic myocardial fibrosis in the family.


RESULTS
Patients presented from adolescence to age >80 years with arrhythmia or chest pain but not heart failure. Desmosomal mutations were identified in 8 of 24 families (15 of 33 patients). Magnetic resonance findings included LV late-enhancement in a subepicardial/midwall distribution, corresponding to fibrofatty replacement and fibrosis on histopathology. Fifty percent had previously been misdiagnosed with viral myocarditis, dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy, or idiopathic ventricular tachycardia. Arrhythmic events included presentation with ventricular fibrillatory arrest in 1 patient and 2 instances of sudden cardiac death during follow-up.


CONCLUSIONS
Arrhythmogenic cardiomyopathy is distinguished from DCM by a propensity towards arrhythmia exceeding the degree of ventricular dysfunction. The left-dominant subtype is under-recognized owing to misattribution to other disorders and lack of specific diagnostic criteria. Clinicians are alerted to the possibility of LDAC in patients of any age with unexplained arrhythmia of LV origin, (infero)lateral T-wave inversion, apparent DCM (with arrhythmic presentation), or myocarditis (chest pain and enzyme rise with unobstructed coronary arteries).
Sen-Chowdhry
Srijita
S
Inherited Cardiovascular Disease Group, The Heart Hospital, London, United Kingdom. srijita@aol.com
Syrris
Petros
P
Prasad
Sanjay K
SK
Hughes
Siân E
SE
Merrifield
Robert
R
Ward
Deirdre
D
Pennell
Dudley J
DJ
McKenna
William J
WJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D009202:Cardiomyopathies / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D015331:Cohort Studies; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000473:pathology; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*; D055815:Young Adult