Effects Of Hypertension On Left Ventricular Wall Size In Nigerians From The Owerri Heart Study

Abstract

Background and Purpose: The rising prevalence of hypertension in Nigerians may account for the increase in rate of cardiac diseases, most often associated with left ventricular hypertrophy(LVH), an end-point measure of cardiac end-organ damage. The study cohort drawn from the Owerri Heart Study (OHS) were examined to determine the left ventricular posterior wall thickness (LVPWT) at the different levels of blood pressure according to the classification of the Seventh Joint National Committee (JNC 7) report.

Methods: One hundred and eighty consecutive patients including 108 men and 72 women of mean age 53.214 years, were clinically evaluated by measurements of systolic (SBP) and diastolic (DBP) blood pressure using mercury sphygmomanometer. The blood pressures were classified according to the JNC 7 report. The LVH was determined by measurement of feft ventricular posterior wall
thickness (LVPWT) using two dimensional (2-D)} Color Flow Echocardiography.

Results: Patients with normal blood pressure (SBP = 114.7+11.7 mmHg, DBP = 69.43 mmHg) were n=17, the LVPWT = 14.142.2mm. Patients with Pre-hypertension (SBP = 133.8218.5 mmHg, DBP = 80.1£0.85 mmHg) were n = 33, LVPWT = 15.442.74mm. Patients with Stage 1 hypertension (SBP = 144£13.9 mmHg, DBP = 90.1+0.9 mmHg) were n = 59, LVPWT = 15.2+£2.6mm. Patients with Stage 2 hypertension (SBP = 159.6220.6 mmHg, DBP = 106.7+10.4 mmHg) were n=71, LVPWT = 16.67£3.5mm. Analysis of variance (ANOVA) revealed significant differences in SBP F(3, 176) = 37.68, p< 0.0001, DBP F(3, 176) = 217.7, p< 0.0001, and LVPWT F(3, 176) = 4.66, p< 0.01.

Conclusion: The LVPWT at prehypertension did not differ significantly (p> 0.05) with the LVPWT of normatensives, hypertension Stage 1 and Stage 2. This may suggest that the distinction of prehypertension may include patients with blunted nocturnal fall in BP defined as ‘non-dippers’ that has been associated with increase in left ventricular mass index. This may suggest that, patients with prehypertension should be evaluated for LVH and if present, there should be no delay in early therapeutic intervention with antihypertensive drugs along lifestyle modification.