P324 Left Ventricular Isolated Cardiomyopathy or Dilated Cardiomyopathy: The Role of Genetic Analysis

Abstract

Introduction arrhytmogenic cardiomyopathy (ACM) is a genetic heart muscle disease caracterized by substitution of the ventricular myocardium with fibrofatty tissue. The disease was originally termed “arrhytmogenic right ventricular (dysplasia)/cardiomyopathy” to define a condition which distinctively affected the right ventricle and predisposed to fatal ventricular arrhythmias. New insights led to comprehending that the left ventricle is also frequently affected. Clinical case 62 yo, male, no cardiovascular risk factors, positive history for frequent ventricular premature beats treated with Sotalol 40 mg twice a day. No other previous cardiological events. Accesses the ER with suddenly occured dyspnea for minimal exertion, without palpitation, chest discomfort or loss of consciousness. EKG: synus rhythm, low voltages, negative V4–V6 T waves, fragmented QRS. Blood testing: TnI 0,532 ng/ml (n.v. 0–0.034) NTproBNP 3840. Echocardiography: dilated left ventricle. 20% EF due to infero–lateral wall akynesia. Coronary angiography was performed and showed no coronary stenosis. Considered the frequent NSVTs showed by the telemetry, he was admitted to ICU and treated with Amiodarone, Atenolol 100 mg, Sacubistril/Valsartan 24/26 mg, diuretic therapy showing good control of major arrhytmic events. To evaluate characterize heart tissue, a magnetic resonance was performed, which showed: scalloping of the mid and apical left ventricular lateral wall, with fibrofatty substitution. Subepicardial, mid–wall and transmural LGE of the LV anterior, lateral and inferior walls. No RV abnormalities. Considered the reduced EF and the presence of arrhytmic substratum, an ICD was implanted. Finally, a genetic evaluation was discussed with the patient, but was declined. Discussion in patients presenting with typical LV abnormalities, without RV involvement, the phenotipic Padua criterias are not enough for a certain diagnosis. This is because of the phenotipic overlap between ACM and other diseases, such as dilated cardiomyopathy, myocarditis and cardiac sarcoidosis. In the presence of LV involvement, consistent with ACM, the evidence of a pathogenetic mutation is key for the diagnosis.