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Biomedical subjects

G K Sethi

Publications and source records attributed to G K Sethi.

At least 55 records · Page 3Linked to original sources
PubMed1993

Clinical significance of weight difference between donor and recipient in heart transplantation.

A standard and important criterion for donor acceptance is to match the donor's body weight to within 20% of the recipient's body weight. However, to meet the increasing demand of patients who need heart transplantation, frequently a heart that is below the standard criteria for donation is accepted. Of the 200 consecutive patients who underwent heart transplantation at the University of Arizona, 27 patients received a heart from a smaller donor with a weight difference of more than 30% (range 30% to 46%). The early mortality and late survival of these 27 patients were not different when compared with those of the patients who received transplants from donors with a weight difference of less than 30%. The probability of freedom from rejection and infection and postoperative ejection fraction were also similar between the two groups. Therefore, we believe that the widely accepted donor-recipient weight-match criterion of 20% can be safely extended.

Adult↗
PubMed1993

Central retinal vein occlusion after heart-lung transplantation.

We report two cases of central retinal vein occlusion occurring after heart-lung transplantation in young adults. The patients underwent cardiopulmonary bypass during heart-lung transplantation, which may produce systemic hypotension and increased intraocular pressure. In addition, cardiopulmonary bypass is associated with disturbances in hemostasis and alterations in platelet function. Clotting factors frequently are administered during and after transplantation. Systemic hypothermia also is induced during cardiopulmonary bypass. Postoperatively, these patients developed hypertension and hyperlipidemia secondary to the immunosuppressive therapy used to help prevent rejection. It was postulated that these conditions may predispose a patient to having a central retinal vein occlusion.

Adult↗
PubMed1992

Implications of third heart sounds in patients with valvular heart disease. The Veterans Affairs Cooperative Study on Valvular Heart Disease.

BACKGROUND: The presence of third heart sounds in patients with valvular heart disease is often regarded as a sign of heart failure, but it may also depend on the type of valvular disease. METHODS: We assessed the prevalence of third heart sounds and the relation between third heart sounds and cardiac function in 1281 patients with six types of valvular heart disease. RESULTS: The prevalence of third heart sounds was higher in patients with mitral regurgitation (46 percent) or aortic regurgitation (28 percent) than in those with aortic stenosis (11 percent) or mitral stenosis (8 percent). The left ventricular ejection fraction was significantly lower (P less than 0.001) when a third heart sound was detected in patients with aortic stenosis (0.38, vs. 0.56 in those without third heart sounds) or mixed aortic valve disease (0.40 vs. 0.55). However, the ejection fraction was only slightly lower in patients with mitral regurgitation and third heart sounds (0.51 vs. 0.57, P = 0.03). The pulmonary-capillary wedge pressure was higher (P less than 0.001) when a third heart sound was detected in patients with aortic stenosis (18.6 mm Hg, vs. 12.1 mm Hg in those without third heart sounds). There was no association between the wedge pressure and third heart sounds in patients with mitral regurgitation. The prevalence of third heart sounds increased with the severity of mitral regurgitation. CONCLUSIONS: In patients with mitral regurgitation, third heart sounds are common but do not necessarily reflect left ventricular systolic dysfunction or increased filling pressure. In patients with aortic stenosis, third heart sounds are uncommon but usually indicate the presence of systolic dysfunction and elevated filling pressure.

Adult↗
PubMed1992

Improved sterile technique diminishes the incidence of positive line cultures in cardiovascular patients.

In order to determine the incidence of positive line cultures, especially as affected by differing protocols for line insertion, cultures were obtained from lines in residence for up to 4 days from cardiac patients (who received Cefuroxime) and vascular patients (who received Cefazolin) as prophylaxis perioperatively. Positive cultures were obtained from 95 (19%) of 496 lines in cardiac patients and 83 (31%) of 261 lines in vascular patients. There was a linear relationship between duration of line residence and the incidence of positive line cultures, increasing from 14% on Day 1 to 33% on Day 4. The use of full sterile technique at the time of insertion halved the incidence of subsequent positive line cultures. Four of the 403 (1%) patients each had a single episode of postoperative line sepsis. Another four patients developed wound infections with the same organisms as cultured from their lines. One patient has had a vascular graft infection with the same organism cultured as was isolated from a Swan-Ganz line 1 year previously. These data suggest that monitoring lines should be inserted using full sterile technique and removed as soon as the patient is hemodynamically stable.

Cardiac Surgical Procedures↗
PubMed1992

Peripheral vascular disease in heart transplant recipients.

The improved longevity of heart transplant recipients demands heightened awareness of the long-term complications of the procedure. Between 1979 and 1990, 232 patients received 241 heart transplants at our institution. Accelerated coronary atherosclerosis occurred in 45 (19%) of the 232 patients, typically appearing within 2 years of transplantation, whereas peripheral vascular disease (PVD) appeared in 23 (10%) of the 232 patients, usually within 3 years of transplantation. In the patients with PVD, 13 had occlusive disease, nine had aneurysms, and one patient suffered a vertebral artery dissection. Accelerated coronary atherosclerosis afflicted 12 (52%) of the 23 patients affected by PVD (p < 0.05) and preceded the development of PVD in all 12. Logistic regression analysis revealed risk factors predictive of the development of PVD after transplantation to be a pretransplant history of ischemic cardiomyopathy and posttransplant hypertension and hypertriglyceridemia (p < 0.05), with the presence of more than one risk factor increasing the probability of development of PVD. Those patients thus identified as at risk should be closely monitored for the development of PVD. Aggressive medical management of hypertension and hyperlipidemia in this subpopulation may forestall or prevent the development of peripheral vascular disease after heart transplantation.

Adult↗
PubMed1992

Futility of yearly heart biopsies in patients undergoing heart transplantation.

Three hundred thirty-eight endomyocardial biopsies, performed as part of the routine annual evaluation at 1 or more years after transplantation in 211 patients, were reviewed. In only two instances (0.6%) were the histologic findings suggestive, but not pathognomonic, of acute rejection. Both patients were treated for rejection and are doing well at 4 and 6 years postoperatively. On the basis of the results of this study, we believe that routine yearly heart biopsies in asymptomatic patients are not necessary for long-term care of patients after heart transplantation, and we believe they should be performed only if there is clinical suspicion of rejection or as part of a research protocol.

Actuarial Analysis↗
PubMed1991

Lipid peroxidation: a possible factor in late graft failure of coronary artery bypass grafts.

Atherosclerosis is the paramount cause of late vein graft failure after coronary artery bypass grafting. Lipid peroxidation, which may play a significant role in the initiation and progression of atherosclerosis, was examined in segments of vein grafts (n = 6) harvested at reoperation for coronary disease. These were analyzed for cholesterol, phospholipid, triglyceride, and lipid peroxides. Nonatherosclerotic vascular tissues, including coronary arteries (n = 6), saphenous veins (n = 9), and donor aortic specimens (n = 11) were analyzed for comparison. Risk factors for atherosclerosis including elevated serum cholesterol and triglycerides, smoking, and hypertension were more frequent in patients with coronary artery disease compared to organ donors. Lipid peroxides were elevated in explanted vein grafts when compared to either saphenous vein, coronary artery or donor aorta. Lipid peroxides were not significantly different in saphenous vein when compared to coronary artery, but levels in both of these tissues were greater than in donor aorta. Although increased levels of lipid peroxides in explanted veins may simply reflect morphologic changes in these grafts, the known effects of lipid peroxides on a number of biochemical events suggest that they may contribute directly to graft failure after coronary artery bypass grafting.

Adolescent↗
PubMed1991

Abdominal aortic aneurysm in the patient undergoing cardiac transplantation.

In the past 3 years at our institution 130 patients have undergone cardiac transplantation for ischemic cardiomyopathy in 49 (38%), idiopathic cardiomyopathy in 42 (32%), viral cardiomyopathy in 9 (6.9%), pulmonary hypertension in 8 (6%), and graft atherosclerosis in 2 (1.5%). Routine preoperative abdominal ultrasonography was performed on 98 (75%) of these patients with specific visualization of the abdominal aorta in 93 (95%). Abdominal aortic aneurysms (all infrarenal) were found before operation in four patients and only in the subgroup undergoing transplantation for ischemic heart disease (10.5%). They measured 3.4, 4.5, 3.6, and 3.8 cm before transplantation. Periodic evaluation by ultrasonography was carried out after transplantation during the 3-year period of this study. One aneurysm that was initially 3.6 cm increased to 4.0 cm and ruptured 2 months after transplantation. The patient died despite emergent surgery. Aneurysms in three patients who demonstrated rapid aneurysm expansion after transplantation were successfully repaired at 5, 20, and 33 months after transplantation when the lesions reached 5.5, 5.9, and 4.8 cm. A fifth patient with an initially normal (1.5 cm) aorta developed a symptomatic aneurysm of 4.1 cm, which was repaired uneventfully. The average expansion rate of these aneurysms after transplantation was 0.74 +/- 0.15 cm/year. This experience suggests that aneurysms are limited to patients undergoing transplantation for ischemic heart disease. Ultrasound examination may be appropriate for preoperative screening. Careful aortic surveillance after transplantation is important in patients having transplantation for ischemic cardiomyopathy because of the apparent rapid expansion rate compared to aneurysms in the population not receiving transplants.

Aorta, Abdominal↗
PubMed1991

Comparison of postoperative complications between saphenous vein and IMA grafts to left anterior descending coronary artery.

Considerable controversy exists regarding relative morbidity associated with the saphenous vein graft (SVG) and internal mammary artery (IMA) graft in patients undergoing myocardial revascularization. As a part of the cooperative study on use of antiplatelet drugs for graft patency, operative and postoperative data were prospectively collected on 1,150 patients who underwent either SVG (n = 656) or IMA anastomosis (n = 494) to the left anterior descending coronary artery. There were no differences in baseline characteristics of patients, distribution of randomization among treatment groups, and total number of distal anastomoses performed between the two groups. The aortic cross-clamp time, cardiopulmonary bypass duration, operative time, and chest tube drainage were greater (p = 0.0001) in the patients with IMA grafts compared with SVG. However, there was no difference in the operative mortality rate, the amount of blood and blood products received, the reoperation rate for control of postoperative bleeding, and incidence of wound complications between the two groups. The early and 1-year patency rates for the IMA were slightly but not significantly better than the SVG patency rates (92.8% versus 90.1% for 1-year patency; p = 0.309). In conclusion, use of IMA is associated with a longer operative time as well as increased postoperative bleeding compared with the SVG. It, however, does not increase operative mortality or postoperative morbidity.

Aged↗
PubMed1991

Impact of resident training on postoperative morbidity in patients undergoing single valve replacement. Department of Veterans Affairs Cooperative Study on Valvular Heart Disease.

As one of the requirements of the Department of Veterans Affairs cooperative study on valvular heart disease, operative and postoperative data were prospectively collected in 964 patients undergoing single valve replacement. The procedure was performed either by a resident under the direct supervision of an attending surgeon (49.5%) or by an attending surgeon (50.5%). There was no difference in operative mortality between the two groups of surgeons when adjusted for patient-related and disease-related risk factors. The proportion of patients who had at least one postoperative complication was slightly but not significantly higher in the attending group (35.8% versus 30.4% for aortic valve replacement, 38% versus 28% for mitral valve replacement, and 36% versus 30% for all single valve replacement procedures). As the significance of each complication varies, we weighted each complication to the associated operative mortality to formulate the morbidity score. An expected complication rate for each group was derived from a multivariate logistic model, and the ratio of observed to expected morbidity was calculated to adjust observed morbidity according to the risk of patients. There was no difference in the observed/expected morbidity ratio between the two groups of surgeons. We conclude that currently used teaching techniques and philosophy to educate cardiac surgical residents, which allow them to take progressive responsibility for cardiac surgical procedures, are well justified, and patient care does not suffer when resident training is enhanced.

Aortic Valve↗
PubMed1990

Implications of preoperative administration of aspirin in patients undergoing coronary artery bypass grafting. Department of Veterans Affairs Cooperative Study on Antiplatelet Therapy.

The perioperative consequences of preoperative aspirin administration were assessed in a large prospective cooperative study of 772 patients undergoing coronary artery bypass grafting. The 772 patients were randomized to receive either aspirin (325 mg once a day), aspirin (325 mg three times a day), aspirin plus dipyridamole (325 and 75 mg together three times a day) (aspirin group), sulfinpyrazone (267 mg three times a day) or placebo (nonaspirin group). The therapy, except in the aspirin group, was started 48 h before the operation. In all aspirin subgroups, one 325 mg aspirin dose was given 12 h before surgery and maintained thereafter according to the assigned regimen. Patients in the aspirin group had significantly more postoperative bleeding and received more packed blood cells and blood products than did patients in the nonaspirin group. Although total operative duration and cardiopulmonary bypass duration were not different, the interval between completion of cardiopulmonary bypass and wound closure was significantly longer (p = 0.035) in the aspirin group. Thirty-one (6.6%) of 471 patients in the aspirin group and 5 (1.7%) of 301 patients in the nonaspirin group also required reoperation for control of postoperative bleeding (p = 0.002). The site of bleeding found at reoperation was not different between the two groups. There was no difference in operative mortality rates, incidence of other bleeding complications or occurrence of other post-operative complications between the two groups. Thus, antiplatelet regimens involving preoperative initiation of aspirin therapy, which has been shown to improve graft patency, increase the risk of abnormal postoperative bleeding and the need for reoperation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspirin↗
PubMed1990

Left atrial dimension and risk of systemic embolism in patients with a prosthetic heart valve. Department of Veterans Affairs Cooperative Study on Valvular Heart Disease.

The relation between left atrial dimension measured by M-mode echocardiography and systemic embolization after valve replacement was examined prospectively among 397 patients with a prosthetic valve enrolled in the Department of Veterans Affairs Cooperative Study on Valvular Heart Disease. Baseline characteristics including several measures of left atrial enlargement were compared for 31 patients who developed systemic embolism and 366 who did not develop embolism during a 5 year follow-up period. Variables that were significantly related to left atrial dimension or systemic embolization in univariate analyses were included with several others in a multiple logistic regression model. The incidence rate of systemic embolism was more than three times higher after mitral valve replacement than after aortic valve replacement (4.4 and 1.3 per 100 patient-years, respectively); this difference persisted after adjustment for other factors. Univariate analysis indicated a threefold higher incidence of systemic embolism in patients with a left atrial dimension greater than or equal to 4 cm compared with that in patients with a dimension less than 4 cm (3 versus 1 per 100 patient-years, respectively). However, when the effect of valve location (mitral versus aortic) was taken into account using either univariate or multivariate techniques, left atrial dimension was found not to be associated with systemic embolism. In multivariate analysis, atrial fibrillation, age, ejection fraction and location of the prosthetic valve were significantly associated with embolism. Results of this multicenter study suggest that left atrial dimension is not independently related to the development of systemic embolism in patients undergoing valve replacement.

Aortic Valve↗
PubMed1990

Rabbit antithymocyte globulin. A 10-year experience in cardiac transplantation.

Rabbit antithymocyte globulin, a "custom-made" pan-anti-T-cell antibody produced in rabbits, is currently being evaluated in the United States and may, within several years, become approved by the Food and Drug Administration. Because we have used this agent for induction of immunosuppression for 10 years in cardiac recipients and because the results appear to be more favorable than those obtained with other agents (horse antithymocyte globulin, antilymphocyte globulin, OKT3), we have reviewed our experience. For the purpose of analysis, all non-bridge-to-transplant cardiac recipients have been divided into three groups on the basis of immunosuppression protocol: group I (March 1979 to January 1983), 28 patients treated with rabbit antithymocyte globulin, steroids, and azathioprine; group II (January 1983 to March 1985), 29 patients treated with rabbit antithymocyte globulin, cyclosporine, and steroids; and group III (March 1985 to January 1989), 98 patients treated with rabbit antithymocyte globulin, cyclosporine, steroids, and azathioprine. Actuarial data showed advantage for group III in survival rate (1 year 94%, 2 years 91%, 3 years 88%), freedom from rejection (30% free at 1 year), freedom from infection (50% free at 1 year), freedom from death from rejection (99% free at 1 year), and freedom from death from infection (97% freedom at 1 year). Actuarial survival rates and freedom from death from rejection and infection are comparable for any of our groups with contemporary published data. In the past 3 years, we have had no death from acute rejection or from posttransplant infection. Time-related rates of infection by etiologic agents have shown a significant reduction in early bacterial, viral, and nocardial infections between groups I and III. With rabbit antithymocyte globulin 200 mg intramuscularly every day for 3 days, our current protocol, T-cells are significantly reduced and local and systemic toxicity is almost unnoticeable. A progressively increasing cyclosporine dose along with rapid tapering steroid and maintenance azathioprine immunosuppressive induction appears to be the therapy of choice in cardiac transplantation.

Actuarial Analysis↗
PubMed1989

Thromboembolic complications of the Symbion AVAD System.

The Symbion Acute Ventricular Assist Device (AVAD) System is an experimental paracorporeal pulsatile ventricular assist device (VAD) for single or biventricular assist. Eleven patients were implanted but 2 died within 24 h and were excluded from the study. Nine patients, four with left ventricular assist devices (LVADs) and five with biventricular assist devices (BIVADs), with a mean implant time of 24 days, were studied to determine the incidence and site of thrombus formation within the device and the incidence of thromboembolic complications. Anticoagulation consisted of heparin titrated to keep the partial thromboplastin time (PTT) twice control and dipyridamole 50 to 200 mg q6h p.o. Seven of nine patients (78%) developed thrombus; five had thrombus visible within the clear housing of the device during the implant period, and two patients had thrombus discovered only after VAD explantation. Common sites of formation were the diaphragm-housing junction, the housing near the outflow orifice, and the de-airing port. Three patients with thrombus developed thromboembolic complications; two suffered strokes and one had multiorgan emboli. The Symbion AVAD System has significant thrombogenic properties that may limit its clinical application.

Cerebrovascular Disorders↗
PubMed1989

Heart-lung transplantation: the initial Arizona experience.

Since November 1985, cardiopulmonary transplantation has been performed at the University of Arizona heart transplant program. Seven patients, five women and two men, have undergone heart-lung transplantation. Five patients had primary pulmonary hypertension, and two patients had Eisenmenger's complex. The mean age was 31 years (range, 17 to 43 years). Average follow-up was 15 months (range, 3 to 34 months), with a total of 115 patient-months. There have been no operative or late deaths. Immunosuppression consisted of rabbit antithymocyte globulin, cyclosporine (Cyclosporin A), azathioprine, methylprednisolone, and prednisone. Our first five patients were aggressively diagnosed and treated for rejection by endomyocardial biopsy, with each patient having one or several treatments for acute rejection. These five patients had one or several episodes of severe infection, particularly cytomegalovirus. In our last two patients we omitted routine heart biopsies. Only those rejection episodes diagnosed by chest x-ray films are considered significant. Our last two patients have not been treated for acute rejection and have had no infections. Presently our immunologic surveillance consists only of careful clinical examination and frequent chest x-ray films. Any changes in the patient's condition are aggressively investigated, searching for infection or rejection. Two patients have been used as domino donors of their native heart.

Acute Disease↗