The determinants of diastolic dysfunction in patients with systemic hyperte
nsion are not completely known. To evaluate the possible role of age, arter
ial blood pressure, and baroreflex heart rate response impairment in causin
g diastolic dysfunction, we studied 61 patients (42 male; mean+/-SD age, 43
.9+/-12 years) with newly recognized and therefore previously untreated sys
temic hypertension, Diastolic dysfunction was evaluated by means of Doppler
echocardiography (and diagnosed as such when the early to atrial peak velo
city ratio corrected to heart rate was <1), arterial blood pressure by 24-h
our ambulatory monitoring, and baroreflex heart rate response by means of t
he spectral technique (alpha index) during paced (0.27 Hz) and spontaneous
breathing (in a supine position and during tilt). Nineteen patients had dia
stolic dysfunction, the most powerful predictor of which was age (r=-0.63,
P<0.001). The patients with diastolic dysfunction had significantly lower v
alues for spectral baroreflex gain in the high-frequency band than those wi
thout (5.2+/-3 versus 8.4+/-5 ms/mm Hg during paced breathing, P<0.05; 7.4/-4 versus 13.3+/-7 ms/mm Hg in a supine position, P<0.05; 4.3+/-4 versus 5
+/-2 ms/mm Hg during tilt, P<NS). Ambulatory blood pressure values were not
significantly different in the patients with (137+/-14 and 89+/-9 mm Hg) a
nd without (144+/-11 and 82+/-24 mm Hg) diastolic dysfunction. In conclusio
n, age and impaired baroreflex heart rate response (but not pressure overlo
ad) are determinants of left ventricular diastolic dysfunction in patients
with newly recognized and untreated systemic hypertension.