Search PubMed⌕ Search

Biomedical subjects

D C Sabiston

Publications and source records attributed to D C Sabiston.

At least 73 records · Page 4Linked to original sources
PubMed1983

The role of radionuclide angiocardiography in the preoperative prediction of pain relief and prolonged survival following coronary artery bypass grafting.

Radionuclide angiocardiography (RNA) provides noninvasive measurements of left ventricular function during rest and exercise, which appear to reflect the magnitude of fibrosis and ischemia in patients with coronary artery disease. This investigation evaluated the usefulness of these measurements for providing prognostic information, useful in selecting therapy. The RNA study group included 278 patients with a low resting ejection fraction and coronary artery disease documented by angiography. Patients were followed for up to three years to define survival and incidence of complete pain relief. The 172 patients treated medically had less favorable survival and pain relief than the 106 surgically treated patients. In the medically treated patients, a positive RNA defined a subgroup of 113 patients, with a 20% lower 3-year survival than the 59 patients with a negative RNA. Moreover, comparison of patients receiving medical and surgical therapy following a positive RNA documented a clear improvement in both survival and pain relief for those who showed significant ischemia during exercise and subsequently underwent coronary bypass procedures. In patients with a negative RNA, medical and surgical therapy resulted in a similar survival rate and little difference in pain relief. Calculations comparing the maximal potential increase in survival and complete pain relief, using multiple criteria known to provide prognostic information, identified the exercise response on RNA as the single most important variable for selection of therapy. Therefore, the left ventricular response to exercise provides important prognostic information in patients with low resting ejection fractions, and the results of this procedure can be used to define subgroups of patients who will and will not benefit from coronary artery bypass grafting.

Cardiac Catheterization↗
PubMed1982

Cardiovascular effects of ventilation with positive expiratory airway pressure.

The broad clinical application of positive and expiratory pressure (PEEP) in the treatment of a variety of respiratory disorders has led to the observation that positive airway pressure can result in cardiac dysfunction. Recent attempts to integrate and extend the results of past research have led to diverse explanations of the overall cardiopulmonary effects of PEEP. This review summarizes previous work in the field and attempts to explain the basis of the divergent conclusions of previous investigators. Data are presented from several experimental models, as well as studies in postoperative patients to formulate an overall analysis of the influence of airway pressure on the central circulation. It appears that the effects of PEEP are primarily mechanical and are mediated through a combination of right ventricular preload limitation and outflow obstruction. Both effects are additive in limiting left ventricular preload and can be ameliorated by volume loading in the absence of significant right ventricular or pulmonary vascular disease. Neural, humoral and ventricular interactive forces appear to be insignificant under most circumstances. The clinical implications of these advances in the current understanding of PEEP are reviewed.

Animals↗
PubMed1982

An ultrastructural analysis of breast carcinoma presenting as isolated axillary adenopathy.

Metastatic adenocarcinoma in the axillary lymph nodes of a female patient often originates from a primary tumor in the ipsilateral breast. Mastectomy may be recommended if adenocarcinoma is found in the axillary nodes even when the primary tumor is not clinically detectable. In these circumstances, the recommendation for mastectomy should be based on the firm histologic diagnosis of adenocarcinoma. In the present report, five female patients are discussed who presented with axillary lymphadenopathy without clinically evident breast masses or mammographic evidence of malignancy. Axillary lymph node biopsies, performed in each patient, were inconclusive after conventional light microscopic examination. Electron microscopy established the diagnosis of adenocarcinoma. These findings were complemented by sex steroid analyses of the tumors where possible. Each patient underwent ipsilateral mastectomy, and in each specimen an occult breast carcinoma was found. The necessity of making a precise tissue diagnosis in all cases of metastatic cancer from an unknown primary is stressed, and special techniques to accomplish this must be considered preoperatively. This is particularly important in the female patient with metastatic breast carcinoma in an isolated axillary lymph node, since ipsilateral mastectomy may be curative.

Aged↗
PubMed1982

Surgical correction of congenital malformations of the coronary circulation.

Although a number of congenital malformations of the coronary circulation have been recognized for many years, only in the recent past have these been diagnosed and surgically corrected. These lesions include origin of the left coronary artery from the pulmonary artery, coronary arterial fistulas, coronary arterial aneurysms, origin of the right coronary artery from the pulmonary artery, and membranous obstruction of the ostium of the left main coronary artery. Specific symptom complexes and complications are apt to be associated with each of these conditions. Coronary arteriography is usually diagnostic, and surgical correction is indicated in many instances to prevent serious and often fatal complications. The clinical manifestations, physical findings, diagnosis, and management of these lesions are reviewed. Fortunately, the surgical results are usually quite good.

Adolescent↗
PubMed1982

The effects of airway pressure on cardiac function in intact dogs and man.

Ventilation with positive end-expiratory pressure (PEEP) is associated with reduced cardiac output, but the mechanisms involved are controversial. Possible explanations include increased intrathoracic pressure, reflex changes in myocardial inotropism, pulmonary vascular obstruction and abnormal ventricular interaction. Three types of conscious canine preparations were developed to examine simultaneously each of these factors during ventilation with PEEP. In addition, similar measurements were obtained in patients after cardiac surgical procedures and compared with the results of animal experiments. The primary cause of reduced cardiac output during PEEP appeared to be a diminished end-diastolic volume of the left ventricle, and this appeared to be the result of elevated intrathoracic pressure and increased impedance to blood flow through the lungs. Abnormal interventricular septal shifting and reflex autonomic alterations did not appear to be significant in the normal cardiovascular system. These data provide insight into the cardiac effects of PEEP and emphasize the importance of simultaneous quantification of biventricular performance when assessing cardiopulmonary function.

Animals↗
PubMed1982

Dimensional characteristics of left ventricular function after coronary artery bypass grafting.

During coronary artery bypass grafting, 20 patients underwent epicardial placement of miniature ultrasonic dimension transducers across the minor-axis diameter of the left ventricle to monitor cardiac function postoperatively. Left atrial or left ventricular pressure was measured in all patients, and thermodilution cardiac outputs were obtained routinely. Data from 1, 6, 12 and 20 hours postoperatively were analyzed. Directional changes in systolic shortening of the left ventricular diameter correlated well with stroke volume measured by thermodilution techniques and could be used as an on-line index of cardiac output. In five patients who had preoperative abnormalities in wall motion, systolic bulging of the minor-axis diameter was seen initially after revascularization and then gradually resolved over the next 12 hours. Systolic bulging that did not resolve was the earliest indication of a perioperative myocardial infarction in another patient. The end-diastolic diameter increased progressively in all patients in the first 12 hours postoperatively and was associated with stabilization of cardiac function. This improvement in diastolic left ventricular filling was not reflected (p greater than 0.2) by changes in mean left atrial pressure. Therefore, ultrasonic assessment of left ventricular diameter is a simple, precise and safe method of monitoring systolic and diastolic ventricular function postoperatively.

Adult↗
PubMed1982

The role of bronchoplastic procedures in the surgical management of benign and malignant pulmonary lesions.

Conservative pulmonary resection is appropriate for the majority of patients with endobronchial neoplasms of low-grade malignant potential in the proximal airways and for a small but significant number of patients with carcinoma. A portion of the bronchus is removed, with or without lobectomy, as a sleeve resection and a primary bronchial reanastomosis is performed to preserve ventilatory function. Bronchoplastic techniques can also be used to repair traumatic airway injuries and benign strictures. The present series of bronchoplastic procedures consists of 28 patients undergoing operation with pathological diagnoses of carcinoma in 20, adenoma in six, hamartoma in one, and a post-traumatic laceration in one. There were minimal morbidity and no deaths. From 1947 to 1981 a total of 565 bronchoplastic procedures have been reported in the literature. Of these, 504 were sleeve resections for carcinoma. The remaining 61 bronchoplastic procedures were for either excision of endobronchial adenomas or repair of airway injuries of strictures. It appears that bronchoplastic procedures are the ideal surgical therapy for benign endobronchial lesions, tumors of low-grade malignant potential, such as adenomas, and for repair of airway injuries. This approach is also applicable to a select group of patients with carcinoma of th lung, and long-term survival periods comparable to those achieved by pneumonectomy can be demonstrated.

Adenoma↗
PubMed1981

Syndrome of congenital internal mammary-to-pulmonary arteriovenous fistula associated with mitral valve prolapse.

Congenital fistulas of the internal mammary artery to the pulmonary circulation are rare, with only 12 patients described in the world literature. Two additional patients are now described who have an associated prolapse of the mitral valve, one of whom had mitral insufficiency. In most instances, the arteriovenous fistula is essentially asymptomatic and is often discovered when a continuous murmur is heard on routine chest examination. The definitive diagnosis is made best by selective arteriography. The embryologic origin of these fistulous communications may be the maldevelopment of accessory bronchial arteries arising from the internal mammary artery. In view of the potential risks of congestive heart failure as well as proximal dilation and degeneration of the parent artery, secondary hypertension, and endocarditis, operative closure of the arteriovenous fistula is recommended.

Adolescent↗
PubMed1981

Radionuclide angiocardiography in the diagnosis of congenital heart disorders.

Radionuclide angiocardiography provides a noninvasive assessment of cardiac function and blood flow through the heart and lungs. During the past three years, this procedure has been used at the Duke University Medical Center for evaluation of 343 patients with congenital heart disorders. A review of this experience shows tat the resulting data were frequently useful in the surgical management of these patients. In patients with abnormal blood flow patterns, noninvasive imaging of blood flow was useful before and after operative correction. Radionuclide measurements of left-to-right intracardiac shunts were sufficiently accurate for use in the initial evaluation of patients with murmurs and to document the absence of shunt after operative closure of intracardiac septal defects. Moreover, measurements of right-to-left cardiac shunts were of benefit in the management of children with cyanotic heart disease. Measurements of left ventricular function obtained during rest and exercise were most useful in patients with origin of the left coronary artery from the pulmonary artery and in patients with congenital valvular insufficiency. This experience demonstrates that radionuclide angiocardiography provides important measurements of central hemodynamics and cardiac function which are useful in the management of patients with congenital heart disorders.

Adolescent↗
PubMed1981

Surgical management of congenital coronary artery fistulas.

Congenital fistulas are the most common of the coronary arterial malformations and with the widespread use of selective coronary arteriography are being recognized with increasing frequency. Twenty-eight patients with congenital coronary fistulas have been evaluated at the Duke University Medical Center between 1960 and 1981. An additional 258 patients have previously been reported in the literature, making a total of 286 available for review. The right coronary artery is most commonly involved, and the fistulous communication is most often to the right ventricle, right atrium or pulmonary artery. Slightly more than half of the patients with coronary fistulas are symptomatic at the time the diagnosis is made. Surgical correction is strongly recommended to prevent the development of congestive heart failure, angina, subacute bacterial endocarditis, myocardial infarction, and pulmonary hypertension, as well as coronary aneurysm formation, with subsequent rupture or embolization. There were no operative or late deaths in the patients who underwent operations. Moreover, there have been no recurrent fistulas during a mean follow-up period of ten years. The risks of operative correction appear to be considerably less than the potential for development of serious and potentially fatal complications, even in asymptomatic patients.

Adolescent↗
PubMed1981

Accuracy of diagnosis of coronary artery disease by radionuclide management of left ventricular function during rest and exercise.

Rest and exercise radionuclide angiocardiographic measurements of left ventricular function were obtained in 496 patients who underwent cardiac catheterization for chest pain. Two hundred forty-eight of these patients also had an exercise treadmill test. An ejection fraction less than 50% was the abnormality of resting left ventricular function that provided the greatest diagnostic information. In patients with normal resting left ventricular function, exercise abnormalities that were optimal for diagnosis of coronary artery disease were an injection fraction at least 6% less than predicted, an increase greater than 20 ml in end-systolic volume and the appearance of an exercise-induced wall motion abnormality. The sensitivity and specificity of the test were lower in patients who were taking propranolol at the time of study and in patients who failed to achieve an adequate exercise end point. In the 387 patients with an optimal study, the test had a sensitivity of 90% and a specificity of 58%. Radionuclide angiocardiography was more sensitive and less specific than the exercise treadmill test. The high degree of sensitivity of the radionuclide test suggests that it is most appropriately applied to patient groups with a high prevalence of disease, including those considered for cardiac catheterization.

Adult↗
PubMed1981

Function of the secretory immune system in bronchogenic carcinoma. Immunoglobulin A levels in respiratory secretions.

This study was designed to investigate the association between bronchogenic carcinoma of the lung and elevated immunoglobulin A (IgA) levels in respiratory secretions. Sixty-nine patients underwent bronchoscopic examination for evaluation of benign and malignant pulmonary diseases. The concentration of IgA in bronchoscopic washings was determined by a radioimmunoassay (RIA) procedure. The average IgA concentration in 20 washings from patients with benign disease was 171 micrograms/ml and agreed with reported IgA values in normal human volunteers undergoing bronchoscopic examination. In contrast, the average IgA concentration from patients with non--oat cell bronchogenic carcinoma was greater than 1,000 micrograms/ml, and 80% of these patients had values exceeding 300 micrograms/ml. Furthermore, in 16 of these patients, selectively collected washings had been obtained from the tumor-bearing lung and contralateral normal lung. In this group, elevated levels localized to the tumor-bearing side. In contrast, eight patients with extrathoracic cancer metastatic to the chest had an average IgA value of 160 micrograms/ml, and seven of eight (87%) had concentrations below 300 micrograms/ml. Aside from the association of cigarette smoking and pulmonary cancer, we found no clear relationship between smoking history and the concentration of IgA measured in secretions. Finally, biochemical analysis established that the changes in immunoglobulin levels were specific to the secretory immune system. In conclusion, measurement of secretory immune system components may be useful in the early diagnosis of malignant bronchogenic disease. Biological mechanisms and suggested clinical application are discussed.

Adolescent↗
PubMed1981

Extraction of intramyocardial foreign body utilizing operative ultrasonography.

Technical advances in cardiac surgery have made accessible previously remote regions within the heart and great vessels; nevertheless, limitations in the ability to locate intramyocardial foreign bodies with precision utilizing conventional radiographic techniques, together with the frequent inability to palpate a foreign body located within the walls of the heart chambers, has dampened early enthusiasm for their removal. Despite this, the recognized complications associated with nonoperative management continue to militate for an aggressive approach. The following case illustrates the use of operative high-frequency ultrasonography in the exact localization of an intramyocardial foreign body. The precision thus afforded minimizes operative time, confines the size of the necessary ventriculotomy, and greatly facilitates successful removal.

Adult↗
PubMed1980

Quantitative radionuclide angiocardiography.

This study introduces a new method for calculating actual left ventricular volumes and cardiac output from data recorded during a single transit of a radionuclide bolus through the heart, and describes in detail current radionuclide angiocardiography methodology. A group of 64 healthy adults with a wide age range were studied to define the normal range of hemodynamic parameters determined by the technique. The normal radionuclide cardiac index averaged 3.25 +/- 0.75 liters/min/m2, the end-diastolic volume index was 62 +/- 16 ml/m2, the stroke volume index was 40 +/- 9 ml/m2, and the ejection fraction was 0.66 +/- 0.07. Radionuclide angiocardiograms were performed in patients undergoing cardiac catheterization to validate the measurements. In 33 patients studied by both techniques on the same day, a close correlation was documented for measurement of ejection fraction (r = 0.89) and end-diastolic volume (r = 0.89). Determination of the linear regression equation for the end-diastolic volumes obtained by the two methods (EDVcath = 1.26 x EDVRN - 7.56) permitted correction of end-diastolic volume and provided an approach for calculation of stroke volume and cardiac output. To validate the method of volumetric cardiac output calculation, 33 simultaneous radionuclide and indocyanine green dye determinations of cardiac output were performed in 18 normal young adults and correlated closely over a range of 4-17 liters/min (r = 0.94). These independent comparisons of radionuclide measurements with two separate methods document that initial transit radionuclide angiocardiography accurately assesses left ventricular function.

Adolescent↗