Relation of the Brugada Phenocopy to Hyperkalemia (from the International Registry on Brugada Phenocopy)

Brugada phenocopies (BrPs) are clinical entities that differ in etiology from true congenital

Brugada syndrome but have identical electrocardiographic (ECG) patterns. Hyperkalemia

is known to be one of the causes of BrP. The aim of this study was to determine the clinical

characteristics and evolution of hyperkalemia-induced BrP. Data from 27 cases of

hyperkalemia-induced BrP were collected from the International Registry at

www.brugadaphenocopy.com. Data were extracted from publications. Of the 27 patients

included in the analysis, 18 (67%) were male; mean age was 53 ± 15 years (range 31 to 89).

Mean serum potassium concentration was 7.45 ± 0.89 mmol/L. Type-1 Brugada ECG pattern

was observed in 21 cases (78%), whereas 6 cases (22%) showed a type-2 Brugada ECG

pattern. The Brugada ECG pattern resolved once the hyperkalemia was corrected, with

no arrhythmic events. Estimated time to resolution was 7 ± 3 hours. In 4 cases (16%), a

concurrent metabolic abnormality was detected: 3 (11%) presented with acidosis, 2 (7%)

with hyponatremia, 1 (4%) with hypocalcaemia, 1 (4%) with hyperphosphatemia, and 1

(4%) with hyperglycemia. In 7 cases (26%), provocative testing using sodium channel blockers

was performed, and all failed to reproduce a BrS ECG pattern (BrP class A). Additionally,

no sudden cardiac death or malignant ventricular arrhythmias were detected. Hyperkalemia

was found a common cause of BrP in our International Registry. The Brugada ECG

pattern appears to occur at high serum potassium concentrations (>6.5 mmol/L). The ECG

normalizes within hours of correcting the electrolyte imbalance. Importantly, hyperkalemiainduced

BrP has not been associated with sudden cardiac death or ventricular

arrhythmia.