The Relationship Between Carotid Blood-Flow Velocity and the Left Ventricular Area During Acute Regional Ischemia

Broscheit, Jens-Albert; Weidemann, Frank; Strotmann, Jörg; Steendijk, Paul; Eberbach, Nicole; Karle, Holger; Schuster, Frank; Roewer, Norbert; Greim, Clemens A.

doi:10.1053/j.jvca.2008.02.003

« Previous Next »Journal of Cardiothoracic and Vascular Anesthesia
Volume 22, Issue 6 , Pages 823-831, December 2008

The Relationship Between Carotid Blood-Flow Velocity and the Left Ventricular Area During Acute Regional Ischemia

Jens-Albert Broscheit, MD
- Department of Anesthesiology, University of Wuerzburg, Wuerzburg, Germany
- Address reprint requests to Jens-Albert Broscheit, MD, Department of Anesthesiology, University of Wuerzburg, Josef-Schneider-Strasse 2, D-97080 Wuerzburg, Germany
Frank Weidemann, PhD
- Department of Internal Medicine, University of Wuerzburg, Wuerzburg, Germany
Jörg Strotmann, PhD
- Department of Internal Medicine, University of Wuerzburg, Wuerzburg, Germany
Paul Steendijk, PhD
- Laboratory of Cardiovascular Research, University of Leiden, Leiden, the Netherlands
Nicole Eberbach, MD
- Department of Anesthesiology, University of Wuerzburg, Wuerzburg, Germany
Holger Karle, MD
- Department of Anesthesiology, University of Wuerzburg, Wuerzburg, Germany
Frank Schuster, MD
- Department of Anesthesiology, University of Wuerzburg, Wuerzburg, Germany
Norbert Roewer, PhD
- Department of Anesthesiology, University of Wuerzburg, Wuerzburg, Germany
Clemens A. Greim, PhD
- Department of Anesthesiology, University of Wuerzburg, Wuerzburg, Germany

published online 12 May 2008.

Objective

Myocardial contractility can be described by the relationship between blood-flow velocity in the carotid artery and the left ventricular cross-sectional area. The authors investigated whether critical myocardial ischemia influences the derived contractility index, E′_es.

Design

A prospective animal study.

Setting

A university research laboratory.

Participants

Eleven Göttinger minipigs.

Interventions

Within the closed-chest model, the authors placed a U-shaped 8-MHz miniature Doppler probe around the left internal carotid artery and inserted a combined pressure-conductance catheter into the left ventricular cavity via the right internal carotid artery. A balloon occlusion catheter was placed into the inferior caval vein from a femoral vein and acquired transthoracic-view echocardiographic images. An active coronary perfusion catheter was positioned in the proximal left circumflex coronary (LCx) artery. The LCx bed was perfused with blood from the contralateral femoral artery by using a high-precision–output roller pump.

Measurements and Main Results

Stage analysis during normal perfusion revealed evidence for the following function: E′_es = 0.066 + 0.121 E_es (R = 0.96, R² = 0.92, and p < 0.0001), which agrees with previously determined equations. Under ischemic conditions, the relationship changed to E′_es = 0.048 + 0.196·E_es (R = 0.83, R² = 0.69, and p < 0.0001). The limits of precision to detect changes in contractility by E′_es increased from 16% to 45%; the bias did not notably deviate from zero. The indexes of mechanical dyssynchrony (mechanical dyssynchrony and internal flow fraction) derived from conductance catheter measurements increased significantly.