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Biomedical subjects

A Appelbaum

Publications and source records attributed to A Appelbaum.

At least 55 records · Page 3Linked to original sources
PubMed1977

Afterload reduction and cardiac ouptut in infants early after intracardiac surgery.

Sixteen infants less than 18 months old were studied within 3 hours of intracardiac surgery. Initial mean arterial pressure and systemic vascular resistance levels were higher than normal in each infant (99 +/- 17.2 mm Hg and 48 +/- 18.1 units'm2', respectively [mean +/- standard deviation]); cardiac index was low (1.9 +/- 0.48 liters'min-1-2) and mean left and right atrial pressures were 11.4 +/- 2.39 and 12.5 +/- 3.10 mm Hg, respectively. Mean pulmonary arterial pressure was 29 mm Hg; pulmonary vascular resistance was 8.6 units'm2'. When nitroprusside was infused to reduce mean arterial pressure to about normal, cardiac index increased 17 percent and mean left and right atrial pressures decreased 25 and 22 percent, respectively. Mean pulmonary arterial pressure decreased 31 percent. When atrial pressures returned to initial values after infusion of blood with continued infusion of nitroprusside, cardiac index increased another 24 percent. When administration of nitroprusside was discontinued, cardiac index decreased to 116 percent of the initial value and mean atrial pressure increased to 90 percent of the initial value. The study demonstrated the favorable effect on cardiac output of vasodilator therapy in combination with blood volume expansion in hypertensive infants early after intracardiac surgery. An empirical equation interrelating atrial and arterial pressures and cardiac index was derived from the data.

Blood Pressure↗
PubMed1977

Hemodynamic responses to dopamine infusion at controlled normal and low cardiac output states in the anesthetized dog.

In order to isolate the renal and pulmonary vascular effects of dopamine, we employed a dog preparation utilizing fixed venous return in order to control cardiac output at either a normal or low flow state. Dopamine infusion was carried out at doses of 8 and 16 microng/Kg./min. Heart rate, mean systemic arterial pressure, mean pulmonary artery pressure, and renal blood flow were measured. Changes in mean systemic arterial pressure, mean pulmonary artery pressure, and renal blood flow were not significant at either doses of dopamine. There was a dose-related increase in heart rate, most significant with a dose of 16 microng/Kg./min. and low cardiac output. No evidence was found to substantiate the existence of a specific dopaminergic receptor in the renal vasculature when cardiac output was controlled.

Animals↗
PubMed1977

Thrombosis on Björk-Shiley aortic valve prosthesis. A case report and review of the literature.

A patient who developed thrombosis on a Björk-Shiley aortic valve prosthesis is reported. The patient presented with severe angina pectoris and the main physical findings were absence of the closing click of the prosthetic valve and the presence of systolic and diastolic aortic murmurs. Echocardiography showed early closure of the mitral valve and depressed left ventricular function. An emergency operation was performed and the clot was removed. The patient's recovery was uneventful and he is well one year after surgery. Awareness of the possibility of valve thrombosis is necessary in view of the need for emergency surgical treatment. The literature on the subject is reviewed.

Adult↗
PubMed1976

Early risks of open heart surgery for mitral valve disease.

During 1972 and 1973, a total of 235 patients had open heart surgery for mitral valve disease unassociated with significant aortic or rheumatic tricuspid valve disease. Thirty-one underwent closed heart mitral commissurotomy, without mortality. Of the 204 patients undergoing open operation, 125 had sequential measurement of cardiac output and mixed venous oxygen pressure. The hospital mortality rate was 6.4 percent in the larger group of 204 patients and in the 125 with cardiac output measurements. The rate was greater in those with class IV disability (New York Heart Association criteria) preoperatively than in those with class III or II disability. The mean +/- standard deviation of the average cardiac index early postoperatively was 2.05 +/- 0.579 liters-min--1-m--2. Cardiac index was lower in the patients who died early postoperatively than in those who did not. The probability of hospital death was a significant function of cardiac index. The predicted probability of death was 10 percent with an average cardiac index of 1.42 liters-min--1-m--2 and increased sharply with lower indexes. Cardiac index was lower early postoperatively than preoperatively, and was lower in patients in class IV than in those in class III. There was no significant difference in cardiac index between patients with mitral valve replacement and those in repair. A history of closed commissurotomy, age, duration of cardiopulmonary bypass, duration of cardiac ischemia and method of myocardial preservation did not significantly influence cardiac index or hospital mortality rate. There was no significant relation between mixed venous oxygen pressure and hospital death. Further improvement in results of mitral valve surgery requires adequate preservation of left ventricular performance before, during and after operation.

Adolescent↗
PubMed1976

Ascending vs descending aortic dissections.

One hundred eight patients with spontaneously developing thoracic aortic dissection were seen between 1966-1973, 78 of whom had acute dissection and 30 chronic. The age (49 vs 60 yrs) and incidence of hypertension (32% vs 71%) were significantly lower in the 56 patients in whom dissection originated in ascending aorta than in the 52 patients in whom the dissection originated in the upper descending aorta. The mortality rate in medically treated patients with acute ascending aortic dissection was 88%. Cardiac tamponade was the major cause of death. The mortality rate was significantly lower in those who were treated surgically (24%). Fifteen (54%) of the patients with ascending aortic dissection and significant aortic incompetence did not have aortic valve replacement and only two subsequently (53 and 92 months later) required valve replacement. Although the initial mortality in patients with acute descending aortic dissection treated medically and surgically was similar, the long term survival rate was higher in the surgically treated group. We conclude that ascending aortic dissection and descending aortic dissection have different clinical profiles and prognoses. Immediate surgical intervention is indicated in patients with acute ascending aortic dissection. Patients with acute descending aortic dissection can be treated medically initially followed by early elective operation.

Acute Disease↗
PubMed1976

Surgical treatment of truncus arteriosus, with emphasis on infants and small children.

Two of 10 children with truncus arteriosus, Type I, II, less than 2 years of age, 6 of 7 between 2 and 5 years of age, and all 5 older than 5 years survived after complete repair. Five of the nine hospital deaths are believed related to inadequate intra- and postoperative management. One late death has occurred 42 months postoperatively. The low hospital mortality rates in those 2 years of age and older, good long-term results to date, and the poor prognosis of children not operated upon indicate the advisability of elective repair at age 2 to 3 years. Although results in infants less than 2 years old have not been good, current improvements of intra- and postoperative care and the lack of a better alternative suggest that prompt primary repair is indicated for infants with intractable heart failure or increasing pulmonary vascular resistance.

Age Factors↗
PubMed1976

Surgical treatment for closed thoracic aortic injuries.

Eighteen patients with acute aortic tear secondary to nonpenetrating thoracic trauma and seven with chronic tears have been operated upon. Of the patients with acute injury, 28% had normal chest x-ray on admission. The diagnosis of acute aortic tear was made by aortography in all patients. Two patients died from causes unrelated to the aortic injury. In the group of 18 patients in which some method of perfusing the distal aorta was used, two developed paraplegia; in the group of 7 treated with simple aortic cross-clamping none occurred. The average aortic cross-clamp time 69 and 23 minutes, respectively, and average blood administration 3,139 and 1,700 ml., respectively. We conclude that the diagnosis of acute aortic tear cannot be reliably made on clinical grounds, and that with properly trained personnel the method of choice is usually simple aortic cross-clamping during repair.

Aorta, Thoracic↗
PubMed1976

Opitmal age and results in repair of large ventricular septal defects.

The hospital mortality rate was 9.1 per cent (three deaths) in 33 patients less than 2 years old undergoing primary repair of single large ventricular septal defects (VSD's) since January 1972, and was not related to age; it was zero in 50 patients older than 2 years (Group A). The mortality rate with multiple VSD's was 36.4 per cent, not related to age. Age at operation, preoperative pulmonary vascular resistance, and pulmonary artery pressure were directly related to mean pulmonary artery pressure 5 or more years later in 74 patients (Group B) operated upon between 1955 and 1968. Over-all probability of "surgical cure" for single large VSD (surviving the early and late postoperative period with normal or near-normal pulmonary artery pressure 5 years later) is 92 per cent when pulmonary vascular resistance is 4 units - sq. M. and operation performed at age 27 months, 87 per cent when resistance is 8 and operation done at age 6 months, and 80 per cent when resistance is 12 and operation done at less than 6 months of age. These and other probability curves are examined and compared with natural history to determine optimal age for elective repair for large VSD's.

Age Factors↗
PubMed1975

Quadruple valve commissurotomy.

A 12-year-old girl in congestive heart failure was diagnosed to be suffering from severe polyvalvular disease due to a combination of congenital and rheumatic lesions. Cardiac catheterization demonstrated stenotic lesions of all the heart valves. The child underwent quadruple valve commissurotomy and is symptom free and thriving 2 years later.

Child↗