Kevin Turley

The pathophysiology of failure in acute right ventricular hypertension: hemodynamic and biochemical correlations.

SUMMARY Acute right ventricular (RV) hypertension and failure occur clinically. In this study we examined the mechanism of RV failure. Adult dogs were studied acutely under anesthesia; dogs were instrumented for measurement of pressures and right coronary artery blood flow. Myocardial blood flow and cardiac output were determined with radionuclide-labeled microspheres, and the presence of ischemia was determined by biochemical analysis of ventricular biopsies. RV hypertension was produced by constricting the pulmonary artery and was increased until RV failure occurred, as evidenced by decreased aortic pressure and cardiac output and increased RV end-diastolic pressure. With increasing RV systolic pressure, RV myocardial blood flow failed to increase in proportion to demand. At the onset of RV failure, there was no reactive hyperemia of right coronary flow compared with control, indicating the absence of further coronary vascular reserve; biochemical analysis demonstrated that the RV free wall was ischemic; the LV free wall was not. Infusion of phenylephrine raised aortic pressure and hence, myocardial perfusion pressure; RV failure reversed as shown by decreased RV end-diastolic pressure and increased cardiac output and RV systolic pressure; reactive hyperemia of right coronary flow was restored and the biochemical indexes of ischemia were reversed, demonstrating that ischemia is the cause of failure in acute RV hypertension.

Aortic implantation is possible in all cases of anomalous origin of the left coronary artery from the pulmonary artery

BACKGROUND Anomalous origin of the left coronary artery from the pulmonary artery (PA) optimally is treated by creation of a multiple coronary system. This study explores the use of aortic implantation employing alternative methods to achieve coronary transfer in all patients, regardless of the site of origin of the anomalous coronary artery, avoiding the problems of bypass grafts and tunnel procedures. METHODS During the period 1986 to 1994, 11 patients aged 6 months to 8 years (mean age, 2.6 years) underwent repair. Coronary artery origin from the PA included left sinus in 3, posterior in 2, right sinus in 2, intramural aorta with its orifice at the bifurcation of the main and right PA in 1, high left main PA in 1, high at the bifurcation of main and right PA in 1, and anterior in 1. Findings included angina in 4, prior infarctions in 3, ischemia in 7, left ventricular dysfunction in 6, mitral regurgitation in 5, atrial septal defect in 2, and echocardiograms suggestive of endocardial fibrosis in 4. One patient had prior ligation with ventricular dysfunction and collateralization and recanalization. A single patient was asymptomatic. Repair was accomplished by direct transfer using the PA sinus of Valsalva as a button in only 6; tubular reconstruction was used in 4 when the distance was too great to avoid tension; 2 short tubes were constructed with PA wall in 2 of the 3 left sinus origins, whereas 2 long tubes of PA wall were used (1 high on the left side of the main PA and 1 with left anterior descending origin from the anterior sinus of Valsalva in a patient with malrotation [end neo-artery to side aortic reconstruction]); finally, in situ transfer and intraaortic reconstruction (unroofing and anastomosis) was performed in 1 intramural coronary artery. Division of the PA, mobilization of the distal PA, division of the ductus, and direct reanastomosis of the PA was performed in 3 tubular reconstructions, as well as all 6 direct coronary transfers. RESULTS There were no operative or late deaths. Follow-up of 2 to 100 months (mean, 46 months) revealed no new angina or infarctions, improved function and decreased mitral regurgitation. Echocardiographic and angiographic studies demonstrated patency and prograde flow in the new coronary systems. CONCLUSIONS Aortic implantation is the treatment of choice for anomalous origin of the left coronary artery. Methods such as direct transfer, tubular reconstruction, and in situ transfer make such implantation possible in all patients regardless of the site of coronary origin, distance from the aorta, or coronary artery configuration.

Surgical treatment of truncus arteriosus in the first 6 months of life.

One hundred six infants were seen at the University of California Medical Center between 1974 and 1981 with the diagnosis of truncus arteriosus. One hundred of these underwent physiologic correction prior to 6 months of age. Six infants died prior to operation while undergoing intense medical therapy to improve their basic condition. There were 11 operative deaths with a mortality rate of 11%. Of the 86 long-term survivors, 55 have returned for conduit change because of either body growth or pseudointima proliferation of the conduit. There had been no mortalities at the time of conduit change, and 29 of these were repaired using a straight tube between the ventricle and pulmonary trunk, while 26 had valve conduits placed. Physiologic correction in the first 6 months of life has been accomplished with a low mortality rate and apparent good long-term results with none of the survivors having evidence of elevated pulmonary vascular resistance.

Intraoperative echocardiography for evaluation of congenital heart defects in infants and children

To determine the accuracy, utility, and limitations of intraoperative transesophageal echocardiography (TEE) in infants and children, we performed prebypass and postbypass TEE in 90 children undergoing surgical repair of congenital heart lesions, comparing the results to those obtained using intraoperative epicardial echocardiography and pre- and postoperative precordial echocardiography. Patients ranged in age from 4 days to 21 yr (mean 4.1 yr) and in weight from 3 to 68 kg (mean 15.4 kg). Prebypass, we obtained high-quality, two-dimensional TEE images in 86 patients, with correction of the preoperative precordial diagnosis in 3 and confirmation of the preoperative diagnosis in the rest. Adequate epicardial images were obtained in 78 patients, with confirmation of the preoperative diagnosis in all. Shunt lesions that were well delineated prebypass by both TEE and epicardial imaging included interatrial, interventricular, and atrioventricular septal defect lesions. TEE failed to detect the exact size and location of lesions involving the right ventricular outflow tract, i.e., doubly committed subarterial (supracristal) ventricular septal defects. Regurgitant lesions (n = 30) were identified and their severity evaluated in all patients by both TEE and epicardial imaging. Obstructive lesions (n = 33), excluding those involving the right ventricular outflow tract, were well defined by both echocardiographic approaches. Postbypass, we obtained high-quality, two-dimensional, color and Doppler TEE images in 86 patients and epicardial images in 78 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of coronary artery fistula by two-dimensional echocardiography, pulsed doppler ultrasound and color flow imaging

Ten consecutive patients with a coronary artery fistula, aged 1 day to 4 years, were studied by two-dimensional echocardiography, pulsed Doppler ultrasound and color flow imaging. All patients underwent cardiac catheterization, and seven patients had surgical closure of the fistula. The origin, course and site of drainage of the coronary artery fistula were correctly identified prospectively by echocardiographic examination in all patients. Color flow imaging was particularly helpful in visualizing the site of drainage of the fistula. Diameters of the right and left coronary arteries at their origin and of the aortic root were measured from two-dimensional echocardiographic frames and compared with measurements obtained in normal children. The ratio of coronary artery diameter to aortic root diameter in normal children was 0.14 +/- 0.03 (mean +/- SD) for the right coronary artery and 0.17 +/- 0.03 for the left coronary artery. These normal ratios were greatly exceeded for coronary arteries feeding the fistula, and ranged from 0.68 to 0.84 for the right coronary artery and from 0.34 to 0.52 for the left coronary artery. All anatomic information needed for surgical treatment of coronary artery fistula was consistently obtained by echocardiography with color flow imaging. The fistula was closed from within the heart in five patients and by ligation from the epicardial surface in two patients. In these latter patients, intraoperative color flow imaging at the time of ligation proved to be extremely valuable in achieving complete closure.

Intraoperative echocardiography in infants and children with congenital cardiac shunt lesions: Transesophageal versus epicardial echocardiography

To determine the utility and limitations of intraoperative transesophageal echocardiography in infants and children with congenital intracardiac shunts, intraoperative transesophageal (n = 50) and epicardial (n = 49) echocardiograms were performed before and after cardiopulmonary bypass in children from 4 days to 16 years old and 3 to 45 kg in body weight. A miniaturized transesophageal probe (6.9 mm maximal diameter) was used in 36 patients weighting less than or equal to 20 kg. Epicardial imaging was performed with a 5 MHz precordial probe. The intraoperative transesophageal echocardiographic findings before and after cardiopulmonary bypass were correct and complete in 94% of patients. Transesophageal echocardiography correctly identified atrial septal defects, most types of ventricular septal defects, anomalous pulmonary veins, atrioventricular septal defects, tetralogy of Fallot, truncus arteriosus and double inlet ventricles. It failed to provide a correct diagnosis in only three patients, all of whom had doubly committed subarterial ventricular septal defects. Epicardial echocardiography identified all cases that had a doubly committed subarterial ventricular septal defect. A correct and complete intraoperative diagnosis was obtained with the use of epicardial imaging in 92% before and after cardiopulmonary bypass, but this technique required interruption of surgery and could not be completed in three patients because of induced arrhythmias and hypotension. These results demonstrated that intraoperative transesophageal echocardiography consistently defined important morphologic, color and pulsed Doppler ultrasound features of most congenital shunt lesions. Lesions that involved the right ventricular outflow tract are sometimes difficult to image with uniplane transesophageal echocardiography. There were no complications in any of the 50 subjects.

Iodine Toxicity in a Patient Treated by Continuous Povidone-Iodine Mediastinal Irrigation

Continuous povidone-iodine irrigation is frequently used to treat mediastinitis after median sternotomy and has been considered safe and effective. We describe a 34-month-old patient with mediastinitis after median sternotomy who was treated with continuous povidone-iodine irrigation and who absorbed toxic quantities of iodine (total serum iodine, 9,375 micrograms/dl; normal range, 4.5 to 9.0 micrograms/dl). An unexplained metabolic acidosis developed, along with changes in mental status, and the patient died. This experience and a thorough review of the literature lead us to believe that continuous povidone-iodine irrigation of the mediastinum is contraindicated.

Critical pathway methodology: Effectiveness in congenital heart surgery

Critical pathway methodology has been demonstrated to provide producible reduction in average length of stay (ALOS) in adults in certain diagnostic-related groups and operations such as coronary artery bypass grafting. The efficacy of this approach in congenital heart surgery was explored. Two hundred eighty-six consecutive patients from a health maintenance organization treated by a single surgeon since the institution of diagnostic-related group coding at that health maintenance organization constituted the study group. One hundred fourteen patients were treated at a university hospital without critical pathway methodology (group 1) and 172, subsequently at the health maintenance organization institution using the methodology (group 2). Operation/lesion, age, and diagnostic-related group matching was possible in 61 pairs. Examination of the ALOS Hospital (operative and postoperative days) for the entire cohort revealed a 43.8% reduction in ALOS Hospital (p < 0.0001) and a 39.0% reduction in ALOS Intensive Care Unit (p < 0.0001). There was also significant reduction in ALOS Hospital and ALOS Intensive Care Unit in the operation/lesion-matched subsets. Outcome measures including operative and late mortality, readmission, unscheduled emergency room and clinic visits, and health maintenance organization family assessment survey demonstrated no improvement in outcome with increased hospital stay. Thus, critical pathway methodology when used in patients undergoing a congenital heart operation produces a significant reduction in hospital stay and intensive care unit stay as well as quality patient care with uniformity of outcome.

Pulmonary Valve Replacement for Regurgitation after Repair of Tetralogy of Fallot

In general, it has been thought that pulmonary valve insufficiency is well tolerated when the valve is excised or when the pulmonary annulus has been widened with an outflow patch during repair of tetralogy of Fallot. However, when pulmonary regurgitation is massive or when it is combined with other causes of right ventricular failure, progressive right ventricular dilation may occur in some patients. Pulmonary valve replacement has not been commonly used in the past. From January, 1980, to August, 1982, 12 patients, 11 months to 17 years old, had pulmonary regurgitation treated by insertion of a valve in the pulmonary position 4 1/2 months to 11 years after initial repair of tetralogy of Fallot. All patients had progressive right ventricular failure not responsive to medical management. There were no major outflow tract obstructions, residual ventricular septal defects, or persistent aortopulmonary shunts. All 12 patients underwent patch reconstruction of the right ventricular outflow tract that allowed placement of a larger valve. There have been no operative or late deaths, and each patient has had improvement in functional status. One patient required tricuspid valve replacement 1 1/2 years after pulmonary valve replacement to achieve sustained relief of symptoms. Only 1 other patient required subsequent operation; this was for pacemaker lead changes. These early results suggest that in patients with right ventricular failure, attention should be directed to pulmonary regurgitation since this is a component of failure that is reversible; pulmonary valve replacement carries a low risk, and it can relieve symptoms and prevent further deterioration of right ventricular function.

Intraoperative transesophageal echocardiography of atrioventricular septal defect

To determine the accuracy and utility of single-plane transesophageal echocardiography in analyzing atrioventricular (AV) septal defect, intraoperative transesophageal echocardiography was performed before and after institution of cardiopulmonary bypass in 16 patients (age 24 days to 14 years, weight 3 to 47 kg). Prebypass transesophageal echocardiography (including two-dimensional echocardiography, Doppler color flow mapping and pulsed wave Doppler ultrasound) correctly diagnosed divided AV valve, common AV valve and unbalanced AV valve, as well as atrial or ventricular septal defect, or both, in all cases. It correctly analyzed AV valve regurgitation in all 10 patients with right and all 14 with left AV valve regurgitation and correctly analyzed 30 of 33 additional cardiac anomalies. Transesophageal echocardiography was able to detect the absence of normal pulmonary venous connections but failed to demonstrate all of the complex anomalous pulmonary venous connections in three patients with atrial isomerism. Postbypass transesophageal echocardiography documented the absence of a significant residual shunt in 11 of 11 patients undergoing corrective surgery and verified residual AV valve regurgitation in 7 of 9 patients with tricuspid regurgitation and 11 of 13 with mitral regurgitation. Transesophageal echocardiographic information that altered or refined the surgical treatment was obtained in 5 (31%) of 16 patients. Epicardial and transesophageal echocardiography results were concordant in all 13 patients in whom both were performed. Transesophageal echocardiography provides useful and accurate imaging of the important two-dimensional, pulsed wave Doppler ultrasound and Doppler color flow mapping features in AV septal defect.