Do beta-adrenergic blocking agents increase coronary flow reserve?
Michael Billinger, MDa,
Christian Seiler, MD, FACCa,
Martin Fleisch, MDa,
Franz R. Eberli, MDa,
Bernhard Meier, MD, FACCa and
Otto M. Hess, MD*,a
a Department of Cardiology, Swiss Cardiovascular Center, Bern, Switzerland
View larger version (110K):
[in a new window]
|
Figure 1 Representative recordings of coronary flow velocity signal in a patient with single-vessel disease undergoing percutaneous transluminal coronary angioplasty. The tracings are shown in the panels from top to bottom: electrocardiogram, aortic pressure, instantaneous flow velocity and flow velocity trend. Pharmacologic coronary flow velocity reserve (CFVR) (left): flow velocity at rest = 9.1 cm/s, maximal flow velocity after administration of 18 µg adenosine = 28 cm/s; CFVR: 28/9.1 = 3.1. Determination of postischemic CFVR (right): flow velocity after 1-min balloon occlusion = 28 cm/s; CFVR: 28/9.1 = 3.1. Pharmacologic CFVR after metoprolol (lower panels): flow velocity at rest = 9.7 cm/s, maximal flow velocity after adenosine = 36 cm/s; CFVR: 36/9.7 = 3.7. Postischemic CFVR: postischemic flow velocity = 41 cm/s; CFVR: 41/9.7 = 4.2.
|
|
View larger version (25K):
[in a new window]
|
Figure 2 Rate-pressure product: before (left) and after (right) 5 mg metoprolol, intravenous, at rest as well as during hyperemia. There is a significant reduction in the rate-pressure product after beta-blockade. ADO = adenosine.
|
|
View larger version (29K):
[in a new window]
|
Figure 3 Pharmacologic and postischemic coronary flow velocity reserve (CFVR) increased significantly from 2.1 ± 0.6 to 2.6 ± 0.9, respectively, from 2.7 ± 0.8 to 3.3 ± 1.0 after intravenous administration of 5 mg metoprolol. In two patients, there was no change in pharmacologic CFVR, but in another two patients there was even a decrease in CFVR after beta-blockade. Postischemic CFVR was generally higher than pharmacologic CFVR.
|
|
View larger version (37K):
[in a new window]
|
Figure 4 Coronary vascular resistance was slightly lower (NS) after metoprolol but significantly lower during pharmacologic, respectively, postischemic vasodilation. ADO = adenosine.
|
|
|
