Surgical closed atrial septotomy under transesophageal guidance.

An infant with pulmonary atresia and intact ventricular septum is presented who, after initial patch reconstruction of the right ventricular outflow tract and bidirectional cavopulmonary anastomosis through a fifth median sternotomy, underwent an echocardiographically guided closed atrial septotomy, which resulted in marked long-term clinical improvement. The technique of intraoperative transesophageal echocardiography as used in the presented case represents an expanded role for this diagnostic modality in congenital cardiac surgery.

Cardiovascular surgery in patients with congenital plasma coagulopathies.

From 1978 to 1986, fifteen cardiovascular operations were performed on 13 patients with known congenital bleeding disorders. The patients (10 men and 3 women) had a mean age of 51.1 +/- 3.4 years. Four were seen with cardiovascular lesions and documented hemophilia A (Factor VIII deficiency); 3 had hemophilia B (Factor IX deficiency); 3 had Factor XI deficiency; 2 had von Willebrand's disease, and 1 had dysfibrinogenemia. All patients had a history of major hemorrhage after dental extractions or general surgical procedures, and had clearly documented coagulation disorders on hematological evaluation. Elective cardiovascular procedures performed in these patients included aortocoronary bypass grafting (eight), cardiac valve replacement or repair (five), aortic graft placement (one), and carotid endarterectomy (one). The mainstay of perioperative management included appropriate replacement therapy with blood components. Coagulation factor levels were measured routinely to guide therapy. There were no deaths. Two hemorrhagic complications necessitated reexploration. We conclude that in patients known to have congenital coagulation disorders, cardiovascular operations using systemic heparinization can be performed with minimal morbidity and mortality when carried out with preoperative and perioperative support from the hematology service, adequate replacement therapy using blood components, and careful monitoring of the coagulation status.

Imidazole-buffered cardioplegic solution. Improved myocardial preservation during global ischemia.

Progressive acidosis is a constant finding in global myocardial ischemia and is associated with reduced myocardial contractility after ischemia. The hypothesis tested in these experiments was that imidazole (pKa = 6.7 at 37 degrees C), a commonly used buffer in physiology and microbiology, would provide superior buffering capacity when used in lieu of bicarbonate (pKa = 6.1 at 37 degrees C) in a cardioplegic solution. Twenty-eight isolated, working rabbit hearts were perfused, and preischemic and postischemic determinants of performance were measured. The 30 minute interval of normothermic global ischemia was altered by the injection at 0 and 15 minutes of 2 ml/gm wet weight of a buffered cardioplegic solution. Control hearts received a bicarbonate-buffered cardioplegic solution and experimental hearts received a solution buffered with imidazole. In the imidazole-buffered group, there was a superior recovery of coronary flow, developed left ventricular pressure, peak rate of rise of left ventricular pressure, peak rate of relaxation, and stroke work indices (p less than 0.05). Recovery of mechanical parameters was coincident with an improved acid-base status of the coronary sinus effluent at the end of ischemia. Coronary sinus effluents in the imidazole group had significantly higher pH values and lower partial pressures of carbon dioxide than coronary sinus effluents in the bicarbonate-buffered group (p less than 0.001). The data suggest that improved buffering of the extracellular and possibly intracellular space during global ischemia with a nonbicarbonate buffer is beneficial and provides improved postischemic myocardial recovery.