Worsening of left ventricular diastolic dysfunction during exercise causes decreased exercise tolerance in hypertension.
BACKGROUND
Exercise tolerance is reduced in hypertension. Hypertension affects left ventricular (LV) diastolic filling by causing abnormal relaxation and decreasing compliance.


OBJECTIVE
This study was designed to determine whether worsening of LV diastolic dysfunction during exercise causes decreased exercise tolerance in hypertension.


METHODS
Left ventricular diastolic filling parameters were examined at mitral valve by Doppler echocardiography at rest and at peak exercise in hypertensive patients and were compared with those of age- and gender-matched normotensive individuals. Treadmill exercise stress test was performed according to the Bruce protocol and the exercise time was recorded.


RESULTS
Exercise time was significantly shorter in the hypertensive group than that in the normotensive group (320 +/- 29 vs. 446 +/- 38 s, p 0.03). The hypertensive group demonstrated abnormal relaxation pattern of diastolic mitral inflow at rest, which became pseudonormal at peak exercise (E/A velocity ratio, rest 0.86 +/- 0.06 vs. exercise 1.19 +/- 0.09, p < 0.001). The diastolic mitral inflow pattern remained normal at peak exercise in the normotensive group. The deceleration time and the pressure half time of early mitral inflow at peak exercise were significantly shorter in the hypertensive group than those in the normotensive group (deceleration time, 182 +/- 20 vs. 238 +/- 22 ms, p 0.02: pressure half time, 54 +/- 5 vs. 70 +/- 12 ms, p 0.01).


CONCLUSIONS
This study demonstrates that reduced exercise tolerance in hypertension is associated with worsening of diastolic dysfunction during exercise consistent with an increase in left atrial pressure.
Nair
V M
VM
Division of Cardiology, Long Island College Hospital, Brooklyn, New York, USA.
Tekin
U N
UN
Khan
I A
IA
Rahmatullah
S I
SI
Arora
P
P
Mahankali
B D
BD
Sacchi
T J
TJ
Vasavada
B C
BC
D003187:Compliance; D003971:Diastole / Q000502:physiology; D015150:Echocardiography, Doppler; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D016555:Matched-Pair Analysis; D008875:Middle Aged; D012146:Rest; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology*