R. Nagano et al., CONTRIBUTION OF ATRIAL RESERVOIR FUNCTION TO VENTRICULAR FILLING IN HYPERTENSIVE PATIENTS - EFFECTS OF NIFEDIPINE ADMINISTRATION, Hypertension, 26(5), 1995, pp. 815-819
We designed this study to assess the importance of left atrial functio
n as a contributor to mitral flow velocity pattern in hypertensive pat
ients. In hypertensive patients the early diastolic flow velocity and
ratio of early to late diastolic flow velocity in the mitral flow velo
city pattern increase in association with sublingual administration of
nifedipine. These changes have been interpreted as signs of improved
left ventricular diastolic function; however, the mitral flow velocity
pattern is also affected by various other factors. Thus, the nifedipi
ne-induced changes may not necessarily indicate the improvement of lef
t ventricular diastolic function. Transthoracic Doppler echocardiograp
hic parameters of mitral and pulmonary venous flow velocity patterns a
nd left ventricular M-mode echograms were obtained in 16 untreated hyp
ertensive patients before and after sublingual administration of nifed
ipine (10 mg). Normal values of the parameters were determined in 50 a
ge-matched healthy subjects. After nifedipine peak early diastolic mit
ral flow velocity increased beyond the normal value, although the peak
increasing rate of left ventricular inner dimension, another index of
left ventricular diastolic function, did not recover to the normal va
lue. Peak systolic velocity in the pulmonary venous flow velocity patt
ern increased beyond the normal value, indicating improvement of the r
eservoir function of the left atrium during systole. Nifedipine-induce
d normalization of the mitral flow velocity pattern was associated wit
h further abnormalities of the pulmonary venous flow velocity pattern,
indicating enhanced left atrial reservoir function. Thus, nifedipine-
induced normalization of the mitral flow velocity pattern should be ex
plained not only by the normalization of left ventricular diastolic fu
nction but also by another adaptive alteration in left atrial reservoi
r function in hypertensive patients. Combined analysis of mitral and p
ulmonary venous flow velocity patterns may be useful in avoiding the m
isinterpretation of the mitral flow velocity pattern.