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Biomedical subjects

R B Griepp

Publications and source records attributed to R B Griepp.

At least 163 records · Page 9Linked to original sources
PubMed1975

The superiority of aortic cross-clamping with profound local hypothermia for myocardial protection during aorta-coronary bypass grafting.

Two different operative techniques for aorta-coronary bypass grafting were utilized in two comparable groups of patients. In one group (155 patients) distal anastomoses were carried out with the aorta cross-clamped and myocardial protection provided by profound local hypothermia (clamped group). In a second group (149 patients) distal anastomoses were carried out with the aorta unclamped and the left ventricle fibrillating and vented (unclamped group). Mortality rates were similar in the two groups (0.6 per cent in clamped group versus 1.3 per cent in unclamped group). The incidence of perioperative infarction was 15 per cent in the unclamped group and 8 per cent in the clamped group (p less than 0.05). Postoperative serum glutamic oxaloacetic transaminase (SGOT) and lactic dehydrogenase (LDH) levels were significantly higher for the first 4 postoperative days in the unclamped group than in the clamped group. Hemodynamic studies in a subset of each group revealed no important differences in left ventricular function in the immediate postoperative period. The data demonstrate that in patients undergoing aorta coronary bypass grafting, performance of distal anastomoses with aortic cross-clamping and profound local hypothermia results in less intraoperative myocardial injury than performance of distal anastomoses in the perfused, fibrillating, and vented left ventricle.

Aspartate Aminotransferases↗
PubMed1975

Hemodynamic observations in the early period after human heart transplantation.

Serial hemodynamic measurements, including determination of cardiac output by the Fick technique, were obtained in 10 human cardiac recipients for intervals up to 38 days after transplantation. Immediately postoperatively, donor cardiac output was severely depressed because of limitation of stroke volume. Spontaneous recovery of cardiac output and stroke volume then occurred gradually over the first 4 postoperative days to normal or nearly normal levels. Rate augmentation by arterial and/or ventricular pacing early after transplantation had little effect on donor heart performance, but isoproterenol caused significant enhancement of graft function and is now used routinely in postoperative management. Serial hemodynamic monitoring proved to be of little use in the prediction or confirmation of acute graft rejection episodes.

Blood Pressure↗
PubMed1975

Postoperative hemodynamics following aortic cross-clamping during aortocoronary bypass surgery.

Forty-one patients undergoing aortocoronary bypass surgery were divided into two groups: an "unclamped" group (17 patients) in whom the aorta was not cross-clamped during operation and a "clamped" group (24 patients) in whom the ascending aorta was cross-clamped during performance of distal anastomoses. Myocardial protection was provided during aortic clamping by cooling the anoxic heart with cold saline immersion. Immediate postoperative hemodynamic function was assayed in both groups, as was cardiopulmonary bypass time and cardiopulmonary bypass time/graft. Cardiopulmonary bypass time was 107 minutes in the unclamped group and 87 minutes in the clamped group (P less than 0.05). Cardiopulmonary bypass time/graft was 48 minutes in the unclamped group and 40 minutes in the clamped group (P less than 0.01). Results of hemodynamic studies with values for the unclamped group listed first were as follows: cardiac index (L/min/m2) 2.3 and 2.5 (NS), stroke index (ml/beat/m2) 23 and 25 (NS), left ventricular minute work index (kg-m/min/m2) 3.03 and 2.81 (NS), and stroke work index (g-m/min/m2) 31 and 30 (NS). These data indicate that aortic cross-clamping during performance of distal anastomoses expedites the performance of aortocoronary bypass surgery and does not adversely affect postoperative hemodynamics.

Adult↗
PubMed1975

Surgical treatment of chronic constrictive pericarditis using cardiopulmonary bypass.

The results of operative treatment of 11 patients with chronic constrictive pericarditis with the aid of cardiopulmonary bypass are described. Ten of the 11 patients had Functional Class III or IV disability preoperatively, and all had evidence of severe constrictive disease on physical examination and cardiac catheterization. Pericardiectomy, performed on cardiopulmonary bypass through a median sternotomy incision, required an average total perfusion time of 80 minutes. There were no intraoperative or hospital deaths, and none of the patients required prolonged postoperative hospitalization, All patients except 1, who died 4 weeks postoperatively of pulmonary embolism, have enjoyed marked functional improvement. The technical advantages of pericardiectomy performed on cardiopulmonary bypass are presented.

Adult↗
PubMed1975

Aortic valve allografts for mitral valve replacement.

Between May, 1967, and April, 1971, 122 patients underwent mitral valve replacement with fresh aortic valve allografts mounted on rigid support rings. The operative mortality rate was 6.6 percent. Current evaluation was obtained on all patients; the average postoperative follow-up interval for surviving patients is 4.8 years (range, 3.3 to 7.1). Survival rates 1, 2, and 5 years after mitral valve replacement are 89, 86, and 71 percent, respectively. The average functional class of 90 current survivors is 1.6, as compared to 2.9 preoperatively. Thirty-six thromboembolic episodes have occurred in 28 patients, generating a thromboembolism rate of 7 percent per patient year of analysis. Allograft valve dysfunction has occurred in 64 patients, requiring reoperation in 16 and causing death in two. The linearized valve dysfunction rate is 13 percent per patient year. Pathological examination of recovered allograft valves revealed predominantly leaflet fibrosis and calcification, acellular collagenous valve matrix, and infiltration with chronic inflammatory cells. The results of this long-term analysis indicate that mitral valve replacement with fresh aortic allografts provides significant functional improvement and an acceptably low rate of thromboembolism. However, the time-related rate of allograft valve dysfunction is unacceptably high and does not justify further clinical use of this type of bioprosthesis.

Adolescent↗
PubMed1975

Prosthetic replacement of the aortic arch.

Four patients are reported in whom the aortic arch and variable portions of the ascending and descending aorta were replaced with a prosthesis. In three patients the preoperative diagnosis was dissecting aneurysm of the aortic arch and in one an arteriosclerotic aneurysm of the aortic arch was present. A combination of surface cooling and cardiopulmonary bypass was utilized to produce total body hypothermia. Arch replacement was carried out during a period of total circulatory arrest. Cardiopulmonary bypass was then utilized to warm the patient and resuscitate the heart. The average duration of cerebral ischemia was 43 minutes and the average duration of myocardial ischemia was 74 minutes. The average lowest esophageal temperature was 14 degrees C., and the average lowest rectal temperature was 18 degrees C. Three patients are alive and well 4 to 13 months following surgery. One patient died 4 days postoperatively of pulmonary insufficiency. This experience indicates that by utilizing total body hypothermia and circulatory arrest aortic arch replacement can be carried out with an acceptable mortality rate. Corrective surgery could be offered to patients with life-threatening enlarging aneurysms of the aortic arch.

Aortic Aneurysm↗
PubMed1975

Comparative hemodynamic responses to chlorpromazine, nitroprusside, nitroglycerin, and trimethaphan immediately after open-heart operations.

The hemodynamic effects of intravenous chlorpormazine, nitroprusside, nitroglycerin, and trimethaphan camsylate were studied in 51 patients with high mean arterial pressures immediately after open-heart operations. Chlorpromazine was given by bolus intravenous injection to 24 patients (average dose 10.3 mg); nitroprusside (17 patients), nitroglycerin (8 patients), and trimethaphan (12 patients) were administered by constant intravenous infusion at average doses of 77 mug/min, 59 mug/min, and .097 mg/min, respectively. Measured or derived variables included right atrial pressure, pulmonary artery pressure, left atrial pressure, systemic arterial pressure, heart rate (HR), cardiac index (CI), stroke index (SI), stroke work index (SWI), and systemic vascular resistance index (SVRI). All four vasodilators significantly reduced systemic and intracardiac pressures and SWI (P less than 0.01). Associated changes in left ventricular pumping performance, however, differed importantly between groups. Chlorpromazine caused a significant rise (+19%) in HR with preservation of SI; thus, CI rose significantly (P less than 0.01). Only nitroprusside, however, resulted in enhancement of SI (P less than 0.05) at the lowered left atrial pressure; CI increased by 19% (P less than 0.01), HR rose minimally (6.5%), and calculated SVRI diminished 33% (P less than 0.01). Both nitroglycerin and trimethaphan caused decreases in SI and CI. These results indicate that in general, among the vasodilators studied, nitroprusside is associated with the most favorable hemodynamic responses in early postoperative cardiac surgical patients.

Blood Pressure↗
PubMed1974

Lymphocyte tissue culture studies on human heart transplant recipients. I. Screening recipients for serum factors which inhibit the mixed lymphocyte reaction.

The sera of 20 random human heart transplant recipients, drawn before the administration of immunosuppressive medications, were screened for the presence of factors that might inhibit the mixed lymphocyte reaction. The donors for the lymphocyte cultures were unrelated both to one another and to the heart donor and recipient. Inhibition was defined as a reduction of the number of transformed cells produced in vitro to less than one-third of that produced in autologous serum. It appears that patients who have had previous heart surgery on bypass fare better with heart transplants than those who have not had surgery. This may indicate some change in the overall physiology of the former class of patients resulting in better acceptance of the transplant. In turn, this could be due to the development of a serum factor or an impairment in the patients' cellular immune systems. In the series of recipients studied, the majority possessed serum inhibitory factors possibly non-specific by-products of their heart failure. The precise nature of these factors has yet to be determined. Future research is planned to determine whether bypass surgery is responsible for the stimulation of new immuno-depressive factors or if in some way it boosts the titer of pre-existing factors.

Antibody Formation↗