Background: Left ventricular hypertrophy (LVH) is an independent risk factor for adverse cardiac outcomes in hypertensive patients.
Objective: This study is designed to assess the cardiovascular responses to treadmill exercise among Nigerian hypertensives with echocardiographically proven LVH.
Materials and methods: Fifty hypertensive patients with LVH (27 males and 23 females) between 30 and 65 years of age were studied in Nigeria. 50 hypertensive patients without LVH and 50 normal subjects who were age and sex matched served as controls. All patients and control subjects underwent M-mode, 2-D and Doppler ECHO-studies and the Bruce protocol treadmill exercise test.
Results: The study showed that the estimated maximal oxygen consumption (MVO2) in MET reduced progressively from 8.39 ± 1.26 (normotensive control) to 7.62 ± 1.33 (hypertensive without LVH), 6.27 ± 0.99 (hypertensive with LVH) (P<0.0001ANOVA). The duration of exercise (s) was also reduced in that order from 455.4 ± 79.1 to 411.6 ±8 2.3, 315.8 ± 75.6 respectively (P<0.0001). The systolic blood pressure (SBP) and pressure rate product (PRP) during maximal exercise were also increased in hypertensives with LVH and hypertensive without LVH when compared to normotensive controls. The hypertensives with LVH and hypertensives without LVH also showed significant limitation to heart rate increase with exercise compared to normotensive controls (P<0.003).
Conclusion: This study demonstrated significant impairment of exercise capacity in hypertensives with or without LVH compared to normotensive subjects. Both earlier recognition and improved understanding of LVH may lead to more effective therapeutic strategies for this cardiovascular risk factor.