ABC | Volume 110, Nº2, February 2018

Anatomopathological Correlation Favarato & Benvenuti Cardiomyopathy with arrhythmia and syncope Arq Bras Cardiol. 2018; 110(2):195-200 be asked about the symptoms of syncope, presyncope and heart palpitations. The ECG is mandatory in all patients with sarcoidosis, and if any abnormality is found, echocardiography and other imaging tests, such as magnetic resonance imaging and 14-fluorodeoxyglucose PET, can be useful. 3 The present case could be perfectly diagnosed as sarcoidosis, except for the lack of extracardiac sarcoidosis findings, mainly pulmonary impairment, which is the most common finding. Hypertrophic cardiomyopathy can cause syncope and sudden death. However, our patient showed no cardiac hypertrophy with at least one wall with minimal thickness of 15 mm. 4 Arrhythmogenic ventricular cardiomyopathy is a genetic disease due to mutations in the genes encoding desmosine, characterized by fibrofatty infiltration of the right ventricular myocardium. The changes can begin in three regions of the right ventricle: ventricular inlet, outflow tract and tip. The diagnostic criteria of arrhythmogenic ventricular cardiomyopathy were reviewed by a Task Force in 2010. They comprise electrocardiographic, echocardiographic, magnetic resonance imaging and right ventriculographic findings, family history, and histologic changes on endomyocardial biopsy. On ECG at rest, the major criteria are: T-wave inversion in V 1 to V 3 in individuals aged over 14 years, in absence of right bundle branch block (QRS ≥ 120 ms), epsilon waves at the end of the QRS complex in V 1 to V 2 . The minor criteria are: T-wave inversion in V 1 and V 2 , in absence of right bundle branch block, or in V 4 to V 6 ; or T-wave inversion in V 1 to V 4 at that same age group with right bundle branch block, high-resolution ECG lasting ≥ 114 ms, and low-voltage late potentials (< 40 µV), at the end of the QRS complex, > 38 ms. Regarding the presence of arrhythmia, a major criterion is the occurrence of sustained or nonsustained ventricular tachycardia with morphology of left bundle branch block with superior axis. The minor criteria are: ventricular tachycardia with QRS morphology of left bundle branch block with inferior axis or frequent ventricular extrasystoles > 500/24 hours. On two-dimensional echocardiography, the major criteria are regional right ventricular akinesia, dyskinesia or aneurysm, accompanied by one of the following changes: ventricular outflow tract dilatation (≥ 32 mm) or with correction for body surface ≥ 19mm/m² in parasternal long-axis view; ≥ 26 mm or with correction for body surface ≥ 21 mm/m² in parasternal short-axis view or ejection fraction ≤ 33%. The minor criteria are: regional right ventricular akinesia or dyskinesia and one of the following changes: ventricular outflow tract dilatation ≥ 29 and < 32 mm or with correction for body surface ≥ 16 and < 19 mm/m² in parasternal long‑axis view; or ≥ 32 and < 36 mm in parasternal short‑axis view or with correction for body surface ≥ 18 and < 21 mm/m²; or ejection fraction > 33% and ≤ 40%. On magnetic resonance imaging, the major criteria are akinesia or dyskinesia or dyssynchronous right ventricular contraction, in addition to one of the following changes: right ventricular end-diastolic index ≥ 110 mL/m² (male) and ≥ 100mL/m² (female); right ventricular ejection fraction ≤ 40%. The minor criteria are the motion changes already described as major criteria accompanied by right ventricular end-diastolic index ≥ 100 and < 110 mL/m² (male) and ≥ 90 and < 100mL/m² (female), or ejection fraction > 40% and ≤ 45%. The family history has the strength of a major criterion when arrhythmogenic right ventricular cardiomyopathy is diagnosed in first-degree relatives both by meeting the above-mentioned criteria and by a positive biopsy or postmortem examination, or even when mutations related to the development of cardiomyopathy are confirmed. The minor criteria are: suspected disease in a first-degree relative that cannot be confirmed; sudden death probably due to that cardiomyopathy in a first-degree relative before the age of 35 years; or confirmed diagnosis in a second-degree relative. Regarding endomyocardial histopathology, the major criterion is less than 60% of the myocardial area occupied by cardiomyocytes at morphometric analysis (or <50% if estimated) with fibrous replacement of the right ventricular free wall in at least two endocardial samples, with or without fatty replacement. The minor criteria comprise the same changes described above and a residual myocyte rate between 60% and 75% by morphometric analysis (or between 50% and 65% if estimated). 5 In our patient, we had no access to the original ECG tracing, and, thus, could not use it as a diagnostic method. However, on the electrophysiological study, ventricular tachycardia with morphology of left bundle branch block and superior axis was triggered, a major criterion for that disease diagnosis. The echocardiogram evidenced a dilated and hypokinetic right ventricle, but provided no detail to confirm the diagnosis. Magnetic resonance imaging could not be performed because of the presence of the cardioverter defibrillator, implanted on the beginning of the clinical findings, when syncope was attributed to arrhythmia, which, along with left ventricular dysfunction, would be sequelae of a previous episode of myocarditis. Although magnetic resonance imaging is considered the gold-standard test for the non-invasive diagnosis of that disease, the false-positive rate has been very high. 6 The therapy of choice for patients with arrhythmogenic right ventricular cardiomyopathy is cardioverter defibrillator implantation, because neither the use of antiarrhythmic agents nor ablation on electrophysiological study proved to be reliable alternatives to reduce sudden death. 7 (Desiderio Favarato, MD) Diagnostic hypothesis: arrhythmogenic right ventricular cardiomyopathy. (Desiderio Favarato, MD) Anatomopathological examination The explanted heart weighed 576 g, lacked a large part of the left atrium, was very enlarged and ball-shaped, and had abundant subepicardial fat. Therewas a bulging area of imprecise limits in the right ventricular outflow tract, corresponding to an aneurysmal formation (Figure 1). The right ventricle was markedly dilated and exhibited a metallic lead (cardioverter defibrillator lead) anchored in its apex, focally adhered to the free margin of the tricuspid valve. Extensive, diffuse fatty 197