Echocardiographic Assessment of Cardiac Changes During Normal Pregnancy Among Nigerians.

BACKGROUND: Pregnancy is a physiological process associated with an increased hemodynamic load and cardiac structural remodeling. Limited echocardiographic information exists on cardiac chambers, left ventricular (LV) systolic and diastolic functions, and LV mass during trimesters of normal pregnancy among African women. MATERIALS AND METHODS: Echocardiography was done at the beginning of the second trimester, beginning of the third trimester, and middle of the third trimester for 100 normal pregnant women and at one visit for age-matched 100 nonpregnant women. The data were analyzed using the Statistical Package for Social Sciences (SPSS) version 17 software. Analysis of variance was used to compare within trimesters, and a P value of <0.05 was considered significant. RESULTS: The mean (SD) ages of the patients and controls were 28.20 (±5.91) and 28.35 (±6.06) years, respectively (age range = 19-44 years, P = 0.86). Cardiac chambers, LV systolic function, and LV mass and its index increased significantly during pregnancy. A significant increase in A-wave velocity but slight increase in E-wave velocity and a reduction in tissue e' velocity at the septal margin but a progressive increase in a' velocity were also observed (P < 0.05). CONCLUSION: Cardiac chamber dimensions, LV wall thickness, and mass, most indices of LV systolic and diastolic function, though within normal range, were significantly higher in pregnant than in nonpregnant Nigerian women.

Cardiovascular responses to treadmill exercise in Nigerian hypertensives with left ventricular hypertrophy.

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.

Ambulatory blood pressure profile and left ventricular geometry in Nigerian hypertensives.

BACKGROUND: Left ventricular hypertrophy (LVH) is an independent cardiac risk factor in hypertensives and the structural classification of left ventricular (LV) geometry provides additional prognostic information. Ambulatory blood pressure (ABP) monitoring has been shown to be superior to office blood pressure (BP) in relation to hypertension LVH. We investigated ambulatory BP variables in relation to LV geometric patterns in Nigerian hypertensives. MATERIALS AND METHODS: A total of 130 patients (males = 96, females = 34) with hypertension had their 24-hours ambulatory BP and trans-thoracic 2D/M- mode echocardiography. Data were analyzed with SPSS 13.0. P < 0.05 was considered statistically significant. RESULTS: The mean age of the patients was 54.08±11.88 years. The prevalence rate of abnormal LV geometry was 48.4%. Mean ambulatory Systolic BP (day time, night time and 24-hour-average) was significantly higher in patients with LVH compared with those without LVH. Day-night systolic and diastolic BP decay (i.e. percentage nocturnal decline in BP) was also significantly lower in LVH group than in the group without LVH. Patients with eccentric LVH had abnormal day time mean ambulatory systolic BP, night time mean ambulatory systolic BP, elevated day time and night time systolic BP loads, as well as non-dipping diastolic BP pattern. Significant correlates of LV mass index in this study population were mean ambulatory systolic BP (day time: r = 0.355, P = 0.004; night time: r = 0.343, P = 0.005; 24- hour average: r = 0.358, P = 0.004) and day-night decay (systolic: r = -0.388, P = 0.007; diastolic: r = -0.290, P = 0.022) as well as 24-hour systolic BP variability. CONCLUSION: The presence of LVH in hypertension was associated with higher mean ambulatory systolic BP and lower percentage nocturnal decline in systolic and diastolic BP than its absence which appeared to be worse in patients with eccentric LV geometry when compared with other geometric patterns.

Blood pressure response to an exercise treadmill test, and echocardiographic left ventricular geometry in Nigerian normotensive diabetics.

OBJECTIVES: This study evaluated normotensive diabetic patients' blood pressure response to graded exercise and their echocardiographic pattern of left ventricular geometry. METHODS: A descriptive, cross-sectional, hospital-based study was carried out on 30 normotensive type 2 diabetic patients and 34 controls, aged 30 to 60 years. The outcome measures were to determine the exercise-related variable, blood pressure response, and left ventricular geometry by means of echocardiography. RESULTS: Nineteen (29.7%) and 11 (17.2%) normotensive diabetic subjects had normal left ventricular geometry and concentric left ventricular remodelling, respectively. None of the subjects had concentric or eccentric left ventricular hypertrophy. On this basis, the normotensive diabetic subjects were divided to two groups: G1 (normal) and G2 (concentric left ventricular remodelling). The groups had comparable mean age, body mass index (BMI), fasting blood glucose (FBG) and two-hour post-prandial blood glucose values, and heart rate, systolic (SBP) and diastolic blood pressure (DBP) at rest. G2 patients had higher mean duration of diabetes than G1 subjects (69.0 +/- 9.48 vs 18.7 +/- 8.7 months; p = 0.007). Peak systolic blood pressure was significantly higher in G2 than G1 subjects (213.6 +/- 20.1 vs 200.0 +/- 15.3 mmHg; p = 0.04). Although there was no statistically significant difference in the left ventricular (LV) mass index between the groups, G2 patients had significantly higher relative wall thicknesses than G1 patients (0.53 +/- 0.03 vs 0.41 +/- 0.04; p < 0.001). CONCLUSION: Normotensive diabetic subjects with concentric left ventricular remodelling have increased blood pressure reactivity to exercise. It is probable, as suggested in earlier studies, that increased blood pressure reactivity to exercise is an indicator of target-organ damage, particularly in normotensive diabetics.