Spectrum of hypertensive heart disease in Nigerians: cross-sectional study of echocardiographic indices and their correlation with treadmill exercise capacity

OBJECTIVES: The aims of this study were to provide cross-sectional data on echocardiography in Nigerians with normotension, essential hypertension and hypertensive heart failure, and to correlate the echocardiographic indices with treadmill functional capacity. METHODS: M-mode and two-dimensional echocardiography and a Bruce protocol treadmill test were undertaken in Nigerians with essential hypertension (n = 22) and hypertensive heart failure (n = 12), and in matched healthy volunteers (n = 15). RESULTS: A striking echocardiographic feature was the tendency to eccentric or asymmetric left ventricular hypertrophy in Nigerians. The septum to posterior wall ratios were 1.4 +/- 0.1 in the normotensives, 1.6 +/- 0.1 in the hypertensives and 1.5 +/- 0.1 in the heart failure group. There was a progressive increase in left ventricular mass index and a reduction in fractional fibre shortening in the hypertensive spectrum. Treadmill exercise capacity also showed a progressive fall from normotensives through hypertensives to the heart failure group. A significant positive correlation was found between fractional fibre shortening and treadmill time in the heart failure group. CONCLUSION: In Nigerians with hypertensive heart disease, there was a striking tendency for eccentric (asymmetric) rather than concentric left ventricular hypertrophy. Systolic left ventricular contractility may be predictive of treadmill exercise capacity in hypertensives.