Electrocardiographic correlates of microalbuminuria in adult Nigerians with essential hypertension

Abstract

Microalbuminuria (MA) is a predictor of excess cardiovascular morbidity and mortality in non-diabetic hypertensive patients. This study evaluated the electrocardiographic correlates of MA in adult non-diabetic Nigerians with essential hypertension. Ninety-six newly diagnosed hypertensive patients who consented and met the inclusion criteria for the study were recruited. Ninety-six age- and gender-matched normotensive controls were also studied. Resting 12-lead electrocardiogram of all patients and controls was done and the tracings analyzed by the authors for left ventricular hypertrophy with or without repolarization abnormalities, QTc prolongation, conduction abnormalities and cardiac arrhythmias such as atrial fibrillation. MA was present in 31 (32.3%) of the hypertensive patients and in only six (6.25%) of the normotensive controls. Electrocardiographic left ventricular hypertrophy (ECG LVH) was significantly more commonly found in patients with MA than in patients without it (74.2% vs 40%, p = 0.002). Left ventricular hypertrophy with ischemic pattern was significantly more frequent in the microalbuminuric hypertensive subset than in non-microalbuminuric patients (32.3% vs 13.8%, p = 0.03). The mean QTc were 0.464 ± 0.02 s and 0.428 ± 0.017 s for microalbuminuric and non-microalbuminuric patients respectively (p = 0.01). This study shows that MA is associated with ECG abnormalities such as left ventricular hypertrophy, ischemic pattern ST-T changes and QTc prolongation. This subset of hypertensive patients constitutes a higher risk group and needs intensive monitoring and follow-up. Screening for MA should constitute part of the routine investigation of adult Nigerians with hypertension.
(Cardiol J 2010; 17, 3: 281-287)