title: Selective beta-1 receptor blockade further reduces the mechanically stabilized target coronary artery motion during beating heart surgery.
abstract: OBJECTIVE
  Adequate stabilization of anastomosis sites during off-pump coronary artery bypass is essential to obtain excellent graft patency. We examined the effect of beta-1 adrenergic receptor blockade on the target coronary artery motion by three-dimensional (3D) digital motion capture and reconstruction technology.
  
  
  METHODS
  Eight pigs underwent a sternotomy. Reflection markers were attached to the surface coronary arteries, followed by a mechanical stabilizer application. Two high-speed digital cameras captured two-dimensional (2D) motion of the markers from different angles. These 2D data were reconstructed into 3D data points, representing the motion of each coronary artery. Landiolol hydrochloride, a novel selective beta-1 receptor blocker, was infused intravenously after acquisition of control data.
  
  
  RESULTS
  Beta-1 receptor blockade decreased heart rate (105 ± 16 vs. 90 ± 9 beat/min; P = 0.007) without decreasing arterial blood pressure. The 3D distance moved (millimeter) during one cardiac cycle was significantly reduced on the left anterior descending (9.6 ± 2.8 vs. 6.6 ± 1.9 mm; P = 0.003), left circumflex (10.5 ± 6.3 vs. 6.4 ± 2.6 mm; P = 0.038), and right coronary (8.3 ± 3.6 vs. 6.5 ± 2.1 mm; P = 0.028) arteries. Reduction in the maximal velocity, maximal acceleration, and maximal deceleration of the anastomosis site in all coronary arteries was also found in a quantitative fashion.
  
  
  CONCLUSIONS
  Selective beta-1 receptor blockade significantly reduces the 3D motion at anastomosis sites on the beating heart, with stable systemic blood pressure. Further quantitative investigations of pharmacological stabilization are warranted to achieve better outcome of the patients undergoing off-pump coronary artery bypass surgery.
authors.affiliation: Department of Cardiovascular Surgery, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Wakamatsu
authors.forename: Toshiki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Sato
authors.forename: Shinya
authors.initials: S
authors.lastname: Takase
authors.forename: Sadao
authors.initials: S
authors.lastname: Omata
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yokoyama