title: The influence of collateral flow on the antegrade and retrograde distribution of cardioplegia in patients with an occluded right coronary artery.
abstract: BACKGROUND
  The predictive value of electrocardiography (ECG) and coronary angiography for cardioplegia distribution in patients with an occluded right coronary artery was evaluated.
  
  
  METHODS
  Coronary angiograms and ECGs were evaluated in 15 patients with right coronary artery occlusion. Prediction of antegrade cardioplegia distribution was based on ECG evidence of infarction and coronary collateral flow determined from the angiogram. Antegrade and retrograde delivery of cardioplegia was directly assessed in all patients by myocardial contrast echocardiography. Intraoperative transesophageal echocardiographic images of the right ventricular free wall, the apex, and the intraventricular septum were recorded while 4 ml of Albunex (Mallinckrodt Medical, St. Louis, MO) was injected into antegrade and retrograde cardioplegic catheters during cardioplegia delivery. The observed (myocardial contrast echocardiography) cardioplegia distribution was compared to the predicted cardioplegia distribution. Sensitivity, specificity, positive predictive values, and negative predictive values were calculated.
  
  
  RESULTS
  Eighty seven of 90 (97%) segments were analyzed. Angiography and ECG poorly predicted incomplete cardioplegia distribution. Electrocardiography was a better predictor of inadequate cardioplegia distribution to the right ventricle than was angiography. The negative predicted values of cardioplegia distribution ranged from 20 to 50% for the septum and right ventricle, respectively, with ECG criteria and from 0 to 33% for the septum and apex, respectively, with angiographic criteria. Antegrade cardioplegia delivery was distributed to the right ventricle in 31% of patients, despite 100% occlusion of the right coronary artery; whereas retrograde cardioplegia delivery to the right ventricle occurred 20% of the time.
  
  
  CONCLUSIONS
  In the presence of 100% right coronary artery occlusion, retrograde cardioplegia delivery is not often observed and antegrade delivery of cardioplegia to the right ventricle is not easily predicted. The preoperative angiography and ECG are not predictive of coronary collateral circulation and therefore not predictive of cardioplegia distribution to the right ventricle.
authors.affiliation: Department of Anesthesia and Critical Care, The University of Chicago, Illinois, USA. aronson@dacc.uchicago.edu
authors.forename: S
authors.initials: S
authors.lastname: Aronson
authors.forename: E
authors.initials: E
authors.lastname: Jacobsohn
authors.forename: R
authors.initials: R
authors.lastname: Savage
authors.forename: M
authors.initials: M
authors.lastname: Albertucci
mesh_terms: D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003097:Collateral Circulation / Q000502:physiology*; D017023:Coronary Angiography; D001026:Coronary Artery Bypass; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004452:Echocardiography; D017548:Echocardiography, Transesophageal; D004562:Electrocardiography; D006324:Heart Arrest, Induced / Q000009:adverse effects*; D006801:Humans