Chronic Hypoxemia Depresses Global Ventricular Function and Predisposes to the Depletion of High-Energy Phosphates during Cardioplegic Arrest: Implications for Surgical Repair of Cyanotic Congenital Heart Defects

• Published in: The Annals of thoracic surgery Vol. 37; no. 4; pp. 304 - 308
• Main Authors: Silverman, Norman A., Kohler, John, Levitsky, Sidney, Pavel, Dan G., Fang, Rong B., Feinberg, Harold
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.04.1984; Elsevier Science
• Subjects: Adenosine Triphosphate - metabolism; Anesthesia; Anesthesia depending on type of surgery; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Biological and medical sciences; Cardiopulmonary Bypass; Dogs; Heart - physiopathology; Heart Arrest, Induced; Heart Defects, Congenital - physiopathology; Heart Defects, Congenital - surgery; Heart Ventricles - physiopathology; Hypoxia - physiopathology; Medical sciences; Myocardium - metabolism; Phosphocreatine - metabolism; Stroke Volume; Thoracic and cardiovascular surgery. Cardiopulmonary bypass; Heart; Fissipedia; Carnivora; Energy metabolism; Congenital; General anesthesia; Experimental study; Induced cardiocirculatory arrest; Vertebrata; Mammalia; Hypoxemia; Heart disease; Surgery; Myocardium; Left ventricle performance; Dog
• ISSN: 0003-4975; 1552-6259
• DOI: 10.1016/S0003-4975(10)60735-7

Persistence of impaired ventricular function after repair of cyanotic congenital heart defects may be due to previous exposure to chronic hypoxemia or to perioperative ischemic injury. Clarification of this phenomenon was sought in a canine model of cyanotic cardiovascular disease (Group I), in which the left atrium was anastomosed proximal to the banded pulmonary artery. Animals that had pulmonary artery banding alone (Group II) or no prior surgical intervention (Group III) served as controls. All Group I animals became cyanotic during the study period (arterial oxygen tension, 38 ± 4 mm Hg; hematocrit, 55 ± 5%). Radionuclide-determined ejection fractions performed three months after operation showed significant depression of global biventricular function by 16 to 29% ( p < 0.05) compared with groups II and III. On cardiopulmonary bypass, all hearts were subjected to 4°C potassium cardioplegic arrest and reperfusion with serial assays for myocardial adenosine triphosphate (ATP) and creatine phosphate (CP) levels. The ATP and CP stores in each ventricle were similar at all sampling intervals, and preischemic levels were comparable in cyanotic and control groups. However, ATP levels were significantly depressed 37 to 43% from preischemic levels ( p < 0.02) after arrest and reperfusion in cyanotic dogs, but they were preserved in Groups II and III. During ischemia, CP stores were depleted to 27% of preischemic values in Group I but only to 46 to 63% of preischemic levels in the control groups ( p < 0.05). These data indicate that chronic hypoxemia impairs global ventricular function and predisposes to the accelerated depletion of high-energy phosphates during cardioplegic arrest. The formulation of new intracoronary perfusates for the cyanotic myocardium seems warranted.