TY - JOUR
T1 - Effects of calcium entry blockers on distribution of blood volume
AU - Oren, Shmuel
AU - Gossman, Ehud
AU - Frohlich, Edward D.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1996/7
Y1 - 1996/7
N2 - To evaluate the effects on hemodynamics and the distribution of blood volume of various calcium entry blocker (CEB) agents, we invasively studied 24 hypertensive patients before and after treatment with isradipine, diltiazem, and verapamil. All three agents reduced arterial pressure through a significant fall in total peripheral resistance without causing reflex tachycardia, while preserving stroke volume and cardiac output. Verapamil reduced the central blood volume (CBV) and the ratio of CBV to total blood volume (TBV) in the supine position (P < .05), suggesting peripheral venodilatation. Isradipine and verapamil modified the responses to head-up tilt. The orthostatic decrease in stroke volume was accentuated following treatment, and it was associated with a greater fall in the ratio of CBV to TBV, suggesting that these two agents attenuate the reflex venoconstriction induced by postural change. In contrast to verapamil and isradipine, diltiazem did not affect volume distribution in the supine or head-up positions. These results suggest that the effect of CEBs varies in order of venodilatory effect from verapamil to isradipine to diltiazem, with verapamil having the greatest effect.
AB - To evaluate the effects on hemodynamics and the distribution of blood volume of various calcium entry blocker (CEB) agents, we invasively studied 24 hypertensive patients before and after treatment with isradipine, diltiazem, and verapamil. All three agents reduced arterial pressure through a significant fall in total peripheral resistance without causing reflex tachycardia, while preserving stroke volume and cardiac output. Verapamil reduced the central blood volume (CBV) and the ratio of CBV to total blood volume (TBV) in the supine position (P < .05), suggesting peripheral venodilatation. Isradipine and verapamil modified the responses to head-up tilt. The orthostatic decrease in stroke volume was accentuated following treatment, and it was associated with a greater fall in the ratio of CBV to TBV, suggesting that these two agents attenuate the reflex venoconstriction induced by postural change. In contrast to verapamil and isradipine, diltiazem did not affect volume distribution in the supine or head-up positions. These results suggest that the effect of CEBs varies in order of venodilatory effect from verapamil to isradipine to diltiazem, with verapamil having the greatest effect.
KW - arterial hypertension
KW - calcium entry blocker
KW - diltiazem
KW - Hemodynamics
KW - isradipine
KW - venodilatation
KW - verapamil
UR - http://www.scopus.com/inward/record.url?scp=0030199276&partnerID=8YFLogxK
U2 - 10.1016/0895-7061(96)00034-9
DO - 10.1016/0895-7061(96)00034-9
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C2 - 8806974
AN - SCOPUS:0030199276
SN - 0895-7061
VL - 9
SP - 628
EP - 632
JO - American Journal of Hypertension
JF - American Journal of Hypertension
IS - 7
ER -