Brugada phenocopy in pulmonary embolism - clinicopathological case study and literature review

Brugada syndrome (BrS) is an inherited channelopathy characterized on ECG by coved (type 1) or saddle-back (type 2) ST-segment elevation (STE) of 2 or more mm in the right precordial leads and is associated with an increased risk of malignant ventricular arrhythmias. The term Brugada phenocopy (BrPh) indicates conditions that may reversibly induce Brugada-like ECG pattern in patients without true BrS; e.g.: metabolic abnormalities, mechanical heart compression, ischemia, myocarditis/pericarditis, and pulmonary embolism (PE). Only 9 cases of BPh associated with PE have been described so far. The authors present another case of a 41-year-old-male and analyze the clinical data of all 10 subjects (7 males and 3 females). Type 1 of ECG Brugada pattern was present in 7 patients (including ours), type 2 was found in 2 persons; in 1 case ECG pattern was not defined. In 7 patients STE was prominent (5 mm or more in at least 1 lead). STE was limited to V1-V2 leads in 4 persons, extended to V3 in 3 patients and even to V4 in 3 other patients, which correlated with the significant right ventricular (RV) dilatation. Concomitant left ventricular (LV) systolic dysfunction was reported only in 1 patient, which suggested that paradoxical embolization of coronary artery was not the mechanism of BrS-like STE. Clinical course of PE was usually severe (5 individuals were treated with thrombolysis) and in 3 cases it ended with death. The autopsy was only performed on our patient. It showed diffuse (ischemic) injury of RV and LV secondary to RV overload, decreased cardiac output and severe oxygen deficiency in myocardium, which could have led to BrS pattern in ECG.