| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Laboratoire de Pharmacologie, INSERM E 00.01, Faculté de Médecine Paris Sud, 94270 Le Kremlin-Bicêtre, 2 Service de Cardiologie, Hôpital Antoine Béclère, 92140 Clamart; and 3 Fédération de Cardiologie, Hôpital Henri Mondor, 94000 Créteil, France
The respective contributions of heart
rate (HR) reduction and left ventricular (LV) negative inotropy to the
effects of antianginal drugs are debated. Accordingly, eight
instrumented dogs were investigated during exercise at spontaneous and
paced HR (250 beats/min) after administration of either saline,
atenolol, or ivabradine (selective pacemaker current channel blocker).
During exercise, atenolol and ivabradine (both 1 mg/kg iv) similarly
reduced HR (
30% from 222 ± 5 beats/min), and LV mean ejection
wall stress was not altered. LV dP/dtmax was
reduced by atenolol but not ivabradine. Diastolic time (DT) was
increased by atenolol versus saline (195 ± 6 vs. 123 ± 4 ms, respectively) and to a greater extent by ivabradine (233 ± 11 ms). Myocardial oxygen consumption
(M
O2) was lower under ivabradine and
atenolol versus saline (6.7 ± 0.6 and 4.7 ± 0.4 vs.
8.1 ± 0.6 ml/min, respectively, P < 0.05). Under
pacing, DT and MO2 were similar
between ivabradine and saline but significantly reduced with atenolol.
Thus HR reduction and negative inotropy equally contribute to the
reduction in MO2 during exercise in the normal heart. The negative inotropy limits the increase in DT
afforded by HR reduction.
metabolic demand; chronotropy; inotropy; diastolic time
This article has been cited by other articles:
|
|
 |
|
  L. P. Christensen, R.-l. Zhang, W. Zheng, J. J. Campanelli, E. I. Dedkov, R. M. Weiss, and R. J. Tomanek Postmyocardial infarction remodeling and coronary reserve: effects of ivabradine and beta blockade therapy Am J Physiol Heart Circ Physiol, July 1, 2009; 297(1): H322 - H330. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Milliez, S. Messaoudi, J. Nehme, C. Rodriguez, J.-L. Samuel, and C. Delcayre Beneficial effects of delayed ivabradine treatment on cardiac anatomical and electrical remodeling in rat severe chronic heart failure Am J Physiol Heart Circ Physiol, February 1, 2009; 296(2): H435 - H441. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Logeart, J.-P. Gueffet, F. Rouzet, F. Pousset, C. Chavelas, A. C. Solal, and G. Jondeau Heart rate per se impacts cardiac function in patients with systolic heart failure and pacing: a pilot study Eur J Heart Fail, January 1, 2009; 11(1): 53 - 57. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Heusch, A. Skyschally, P. Gres, P. van Caster, D. Schilawa, and R. Schulz Improvement of regional myocardial blood flow and function and reduction of infarct size with ivabradine: protection beyond heart rate reduction Eur. Heart J., September 2, 2008; 29(18): 2265 - 2275. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. E. Mangoni and J. Nargeot Genesis and Regulation of the Heart Automaticity Physiol Rev, July 1, 2008; 88(3): 919 - 982. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Ciobotaru, M. Heimburger, L. Louedec, C. Heymes, R. Ventura-Clapier, P. Bedossa, B. Escoubet, J.-B. Michel, J.-J. Mercadier, and D. Logeart Effect of Long-Term Heart Rate Reduction by If Current Inhibition on Pressure Overload-Induced Heart Failure in Rats J. Pharmacol. Exp. Ther., January 1, 2008; 324(1): 43 - 49. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Heusch and R. Schulz The role of heart rate and the benefits of heart rate reduction in acute myocardial ischaemia Eur. Heart J. Suppl., September 1, 2007; 9(suppl_F): F8 - F14. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Lucats, B. Ghaleh, X. Monnet, P. Colin, A. Bize, and A. Berdeaux Conversion of post-systolic wall thickening into ejectional thickening by selective heart rate reduction during myocardial stunning Eur. Heart J., April 1, 2007; 28(7): 872 - 879. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Cook, M. Togni, M. C. Schaub, P. Wenaweser, and O. M. Hess High heart rate: a cardiovascular risk factor? Eur. Heart J., October 2, 2006; 27(20): 2387 - 2393. [Full Text] [PDF]
|
|
|
|
|
|
J.-C. Tardif and C. Berry From coronary artery disease to heart failure: potential benefits of ivabradine Eur. Heart J. Suppl., September 1, 2006; 8(suppl_D): D24 - D29. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. Borer Heart rate slowing by If inhibition: therapeutic utility from clinical trials Eur. Heart J. Suppl., September 1, 2005; 7(suppl_H): H22 - H28. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. I. Dedkov, L. P. Christensen, R. M. Weiss, and R. J. Tomanek Reduction of heart rate by chronic {beta}1-adrenoceptor blockade promotes growth of arterioles and preserves coronary perfusion reserve in postinfarcted heart Am J Physiol Heart Circ Physiol, June 1, 2005; 288(6): H2684 - H2693. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
