Clinical correlates of left ventricular mass in elderly hypertensives.

We set out to examine the prevalence of echocardiographically-determined left ventricular hypertrophy (LVH) in a hospital-based population of untreated elderly hypertensives and to study the relationship between left ventricular mass index and clinic and 24h ambulatory BP, urinary electrolyte and microalbumin excretion and ECG changes. We studied 52 untreated elderly hypertensives, mean age 76 years, with no evidence of stroke or heart disease. Subjects underwent 24h ambulatory BP recording together with 24h urine collection for electrolytes and microalbumin estimation. A standard ECG was examined for LVH by commonly used criteria. Subjects were examined by 2-dimensional guided M-mode echocardiography; left ventricular mass was calculated from the formula of Devereux and Riechek and corrected for body surface area (left ventricular mass index, LVMI). Mean LVMI was 168 +/- 39 g/m2 for men and 153 +/- 36 g/m2 for women; 43 (83%) subjects had LVH. LVMI was significantly related to clinic SBP (r = 0.27, P = 0.05), ambulatory daytime SBP (r = 0.27, P = 0.05), nighttime SBP (r = 0.41, P = 0.003) and nighttime DBP (r = 0.29, P = 0.04). LVMI was also related to the difference in mean SBP between day and night (r = -0.32, P = 0.02) and subjects with a day-night SBP difference of > or = 10 mmHg (n = 27) had significantly lower LVMI than those with a day-night SBP difference < 10 mmHg (141 +/- 32 g/m2 vs. 176 +/- 35 g/m2, respectively; P = 0.0005). Fifteen subjects had LVH by ECG criteria giving a sensitivity of 28% and specificity of 66%. LVMI was not related to urinary sodium, potassium or albumin excretion. This study shows that in elderly hypertensives it is measures of nighttime BP which are most closely related to LVMI and subjects with a greater nocturnal fall in BP have lower LVMI, presumably reflecting differences in 24h BP load.