HAEMODYNAMIC EVIDENCE OF A DISPARITY IN THE
DEGREE OF DIASTOLIC DYSFUNCTION IN WOMEN WITH HYPERTENSION. C.S.
Hayward*, W.V. Kalnins, R.P. Kelly. Cardiology Department, St Vincent's Hospital, Sydney, NSW. Women are more
likely to develop left ventricular hypertrophy and diastolic heart failure in
response to hypertension than men. Seventy percent of patients with
hypertensive hypertrophic cardiomyopathy are women. We examined diastolic LV
function using pressure-volume (PV) loops obtained
by simultaneous micromanometer pressure and conductance catheter
volume recordings in 8 postmenopausal hypertensive women with normal
systolic function at routine coronary angiography. Passive diastolic function
was defined by end-diastolic PV relations (EDPVR) during intermittent IVC
occlusion, and active diastolic function by time constant of relaxation, Tau,
and rate of pressure decline, dP/dtmin. In 4 of the women, resting
LVEDP was significantly greater compared to the remainder (17±1 vs 9±1mmHg, p<0.01, mean±SEM). These women were also characterised by smaller indexed LV volumes when compared to the 4
remaining hypertensive women (49±3 vs 59±3 mL/m2, p=0.04). Despite these differences, systolic
pressure (160±6 vs 159±11mmHg) and duration of hypertension (14±7 vs 11±5 years, p=0.70) were remarkably
similar. Those with elevated LVEDP tended to be slightly older (66±4 vs 59±4yrs, p=0.24). Passive diastolic LV
compliance was significantly lower in those with elevated resting EDP (3.0±0.4 vs 4.2±0.4mL/mmHg/m2,
p<0.05). Active diastolic relaxation was also impaired, Tau (53.7 ±1.0 vs 37.9±2.9msec,
p=0.005) and dP/dtmin (-1528±140 vs -1840±96mmHg/sec,
p=0.06). Load-independent indices of systolic function were the similar in the
two groups. Whether these changes are a
manifestation of the aging process or related to individual propensity to
diastolic dysfunction in response to hypertension requires further
investigation.
