Myocardial anaerobic metabolism during isoprenaline infusion in a cyanotic animal model: possible cause of myocardial dysfunction in cyanotic congential heart disease.

Mongrel dogs were made acutely cyanotic by anastomosis of the inferior vena cava to the left atrium and measurements of high fidelity left ventricular pressure, arterial pressure, blood gases, and myocardial lactate arteriovenous differences were determined before pacing, with atrial pacing at a rate of approximately 240 per minute, and during an infusion of isoprenaline to increase myocardial oxygen demands. The animals were divided into two groups on the basis of the arterial PO2 during isoprenaline: acyanotic or control dogs (n = 4, PO2 greater than or equal to 6.7 kPa [50 mmHg], mean = 52) and cyanotic dogs (n = 5, PO2 less than or equal to 4.7 kPa (35 mmHg), mean = 32). Myocardial lactate arterio-venous difference showed no significant changes in the control dogs with pacing or isoprenaline, but myocardial lactate production occurred in all five cyanotic dogs with isoprenaline infusion. These studies demonstrate that myocardial anaerobic metabolism can be produced during times of stress with isoprenaline infusion in a cyanotic animal model at systemic oxygen levels that can occur clinically.

Left ventricular function in cyanotic congenital heart disease.

Left ventricular function was studied with quantitative biplane cineangiocardiography in 39 preoperative and 23 postoperative patients with cyanotic congenital heart disease. Diagnoses included pulmonary atresia or critical pulmonary stenosis with intact ventricular septum (group 1), tricuspid atresia (group 2) and pulmonary atresia with ventricular septal defect (group 3). Preoperative patients ranged in age from 1 day to 7 years and postoperative patients from 7 weeks to 23 years. Left ventricular end-diastolic volume was increased in preoperative patients in groups 1 and 2 (132 and 136 percent of normal, respectively) but was normal in patients in group 3. Left ventricular ejection fraction was decreased to a similar extent in preoperative groups 1 to 3: 0.54, 0.55 and 0.56, respectively. After a shunt procedure left ventricular end-diastolic volume increased to 228 and 266 percent of normal in groups 1 and 2, respectively, but remained within normal limits in group 3. Left ventricular ejection fraction was normal in postoperative group 1 patients, whose ages averaged 1.8 years, but remained decreased in group 2 and 3 patients, whose ages averaged 8.1 and 5.6 years, respectively. Duration of cyanosis and degree of left ventricular dilatation appear to be important variables in regard to pump function in patients with cyanotic congenital heart disease.

Comparative right and left ventricular volumes and pump function in the newborn lamb.

A quantitative cineangiographic method is presented for studying neonatal lamb ventricular volumes and pump function without thoracotomy or surgical instrumentation of the heart. When this method was employed in lambs with a mean age of 24.4 hours it was found that the right and left ventricular end-diastolic volumes, ejection fractions and systolic outputs did not differ significantly at this early postnatal time. Restudy of these lambs at a mean age of 15.6 days showed that right and left ventricular end-diastolic volumes, normalized for body weight, and ejection fractions had not changed significantly. Although systolic outputs decreased, the difference was not significant. Thus there is early postnatal equalization of left and right heart volumes, and deviations from this relation should suggest abnormal hemodynamic function.

Hypoplasia of the systemic ventricle in congenitally corrected transposition of the great arteries: preoperative documentation and possible implications of operation.

This article describes the determination of small systemic ventricular volume by quantitative cineangiocardiography in two patients with congenitally corrected transposition of great arteries, Ebstein's malformation of the systemic atrioventricular valve, and ventricular septal defect. A subjectively small systemic ventricle and an Ebstein-like abnormality of the systemic atrioventricular valve have been described previously in association with congenitally corrected transposition, but in vivo quantification of ventricular size and pump function has not been reported. An initial palliative rather than a totally corrective procedure is probably desirable in patients with this combination of findings. Ventricular volume calculations may prove useful as an aid in selection of operation in this setting.

Total anomalous pulmonary venous connection in infancy. Ten years' experience including studies of postoperative ventricular function.

The surgical experience with total anomalous pulmonary venous connection (TAPVC) at the Venderbilt Hospital between the years 1969 and 1979 was reviewed. Twenty-five patients with TAPVC were studied. All but one patient presented at less than 1 year of age, and 11 patients were operated upon in the first 2 weeks of life. Operative mortality rate was 20% (5/25). Four of the five deaths were in critically ill neonates requiring preoperative ventilatory support. All operative deaths were in patients with pulmonary venous obstruction. All operative survivors have been followed for a mean 4.5 years (6 months to 10 years). There have been no late deaths or cases of symptomatic pulmonary venous obstruction. All children have had normal growth patterns. Ten patients have been recatheterized. Pulmonary artery systolic pressure, which was markedly elevated prior to operation, fell to normal levels after operation. Ventricular function has been evaluated by quantitative angiocardiography in nine patients before and after operation. Left ventricular size and function were markedly depressed preoperatively and rose to normal levels in postoperative survivors. Left atrial maximal volume was found to be 94% of normal values. These data support the contention that preoperative pulmonary venous obstruction is the single risk factor predicting higher risk of operative death. The presence of severe depression of left ventricular size and function preoperatively does not predict a higher operative risk, and postoperative survivors can expect normal ventricular function.

Balloon catheter occlusion of the ascending aorta.

Dense calcification of the ascending aorta predisposes to aortic injury and distal embolization when the aorta is cross-clamped or partially clamped in the performance of cardiac operations. We occluded the ascending aorta with a Foley balloon catheter in 2 patients undergoing aortocoronary bypass grafting. The technique used is described in this report.

Morbidity and mortality of coronary bypass grafting in patients 70 years of age and older.

The hospital mortality and major factors contributing to hospital morbidity and postoperative length of stay were examined in 597 consecutive patients 70 years of age and older who underwent isolated coronary artery bypass grafting (CABG) between January, 1978, and December, 1983. The mean age of the patients was 73 years, and 66% were men. Unstable angina was present in 59% of patients, left main coronary disease in 13%, and moderate or severe left ventricular dysfunction in 10%. The mean number of arteries grafted per patient was 3.4. The hospital mortality was 2.7% (16 patients) and was higher than the mortality among 4,125 patients less than 70 years of age (0.4% in 18 patients) operated on during the same interval (p less than 0.001). In multivariate regression analyses, age of 80 years or greater, evolving myocardial infarction, serious coexisting illness, major left ventricular dysfunction, emergent operation, and the development of major postoperative complications were significant (p less than 0.05) independent predictors of increased hospital mortality. Major complications occurred in 135 patients (23%). In multivariate analyses, the presence of vascular disease, serious concomitant illness, and the need for urgent or emergent operation were significant independent predictors of the development of major postoperative complications. The mean duration of postoperative hospital stay was 10.6 +/- 6 (standard deviation) days. In multivariate analyses, the development of major postoperative complications was the only variable independently predictive of prolonged hospital stay. With current techniques, CABG procedures can be safely performed in the elderly with mortality and morbidity rates only slightly higher than those in younger patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Obturator foramen grafts: the preferable alternate route?

Although the femoral canal is the standard entrance route for vascular grafts to the lower extremity, several situations may arise that preclude the use of this route. In these circumstances an alternate pathway for revascularization is required. Experience in our center with the use of obturator foramen grafts for revascularization of nine limbs in eight patients is reported and underscores the value of this pathway as an alternative route for limb revascularization. The obturator foramen was employed to circumvent an infected arterial prosthesis at the groin level in seven patients (eight limbs) from 12 days to 4.5 years after the initial vascular procedure. The organisms responsible for graft infection included Staphylococcus aureus, Enterobacter cloacae, and Bacteroides fragilis. The final patient required iliac to superficial femoral artery bypass via the obturator foramen to manage occlusion and autolysis of the femoral artery by a mycotic embolus containing beta-hemolytic Streptococcus. Graft material used for these remedial procedures, included saphenous vein (three), Gore-Tex (three), and Dacron (three). Revascularization was satisfactory in each case. Each groin infection healed. Two patients died of unrelated causes at 1.5 and 5 months after operation. The seven remaining grafts at risk (six patients) remained patent 12 months in each case. Four grafts were doing well at 18, 36, 50, and 52 months. Three grafts failed at 13, 19, and 28 months; one was revised successfully, one was re-done and failed again. Obturator foramen bypass grafting provides satisfactory and durable revascularization when an alternate route to the lower extremity is required.

Functional significance of reduced cardiac sympathetic innervation in the newborn dog.

The functional significance of anatomically reduced cardiac sympathetic innervation in the newborn is not known. This problem was investigated by examining ventricular contractile responses to repeated maximal left stellate ganglion stimulation in adrenalectomized and sham-adrenalectomized newborn (4-12 days of age) and adult dogs. At the end of five periods (5 min/period) of stimulation, sham-adrenalectomized puppies were still able to augment left ventricular force 13.0 +/- 3.8% (mean +/- SE; P less than 0.05) above control values. However, adrenalectomized puppies did not maintain their ability to enhance left ventricular force after the first period of stimulation. Similar results were obtained with measurements of the first time derivative of left ventricular force (dF/dt), right ventricular force, right ventricular dF/dt, and peak left ventricular pressure. Adult dogs were able to augment these measurements of cardiac function significantly throughout five stimulation periods whether or not their adrenal glands were intact. After five stimulation periods, adrenalectomized newborn dogs responded to isoproterenol, indicating that their cardiac beta-adrenergic receptors remained functional. We conclude that the known sparse ventricular sympathetic innervation in the newborn dog is associated with inability to maintain significant cardiac functional responses after repeated sympathetic stimulation and that adrenal integrity is required in the newborn to maintain appropriate ventricular responses to sympathetic stimulation.

A reproducible model of chronic hypoxemia.

This report presents our experience with producing a stable chronic hypoxemia preparation in the dog without the disadvantages of prosthetic graft insertion or sacrifice of pulmonary tissue. In 28 adult dogs, the intrapericardial inferior vena cava and the area of junction of the right and left inferior pulmonary veins were exposed through a right thoracotomy. The cava was clamped at the diaphragm and at the right atrium, divided at the atrial clamp, and quickly anastomosed to the inferior pulmonary veins. The mean arterial O2 tension (PaO2) decreased from 83.2 +/- 1.6 mmHg preoperatively in mechanically ventilated (room air) animals to 35.3 +/- 1.5 mmHg postoperatively in awake animals spontaneously breathing room air (P less than 0.001). There was persistent depression of the PaO2 (49.1 +/- 1.8 mmHg) and elevation of the hematocrit (64.8 +/- 2.0%) in six animals tested at 18.5 mo postoperatively. Shunt patency without significant stenosis was confirmed in each animal at autopsy. This method attains predictable and persistent hypoxemia and polycythemia and is simple to perform. It may be useful in studying various aspects of ventricular function and ventricular histological and biochemical changes with chronic cyanosis.

Major hepatic resection.

Among 75 major hepatic resections from 1968 to 1978, 58 were done for severe, devitalizing hepatic trauma, two thirds of which was blunt trauma. Anatomic lobectomies were done in 32 of the trauma cases. Of the 42 patients who survived, 17 had complications postoperatively. Five patients died intraoperatively of exsanguinating hemorrhage. Eleven additional patients died between days 1 and 42, four of them within two days of cardiovascular collapse. Seventeen major resections for tumor and other conditions carried a 12% mortality; four patients each had one complication postoperatively. These cases were compared with the 50 cases previously reported from this institution, totaling 125 major hepatic resections. Despite increasing severity of injury, mortality in such trauma victims has improved from 33% in the previous series to 28% in this series; it was 24% in the latter half of this series. Mortality for elective resections has improved from 23% in the earlier series to 12% in this series. Postoperative morbidity also was reduced.

Restrictive cardiomyopathy in an infant with massive biatrial enlargement and normal ventricular size and pump function.

Restrictive cardiomyopathy in an infant with massive biatrial enlargement and normal ventricular size has been reported only once previously [3]. We now present a 13-month-old patient with severe and progressive congestive heart failure who demonstrated normal ventricular cavity size with biatrial enlargement. Ejection fraction and echocardiographic ventricular function studies were normal.