PubMed Health⌕ Search

Biomedical subjects

O H Frazier

Publications and source records attributed to O H Frazier.

At least 235 records · Page 13Linked to original sources
PubMed1992

Device-supported myocardial revascularization: safe help for sick hearts.

Although advances in both the technology of artificial oxygenation and our understanding of myocardial preservation have made aortocoronary bypass operations safer, clinical settings remain where even these improvements have limited efficacy. We have recently treated 43 severely ill patients with aortocoronary bypass, using a ventricular assist device for intraoperative hemodynamic support and ventricular decompression. For 34 of the patients, preoperative ejection fractions (multigated acquisition) ranged from 0.12 to 0.28 (average, 0.22); 6 patients manifested cardiogenic shock preoperatively, and emergency operations precluded multigated acquisition studies. Twenty-nine patients had preoperative evidence of congestive heart failure, 10 had a prior bypass operation, 9 had major chronic obstructive pulmonary disease, and 2 were Jehovah's Witnesses. The operative technique involved minimal doses of heparin (1 to 1.5 mg/kg), no cardioplegia, and no cardiopulmonary bypass. Revascularization was accomplished on beating, nonworking hearts, with right (40 of 43) and left (43 of 43) ventricles supported by Nimbus Hemopumps (4 of 43) or Bio-Medicus centrifugal ventricular assist devices for an average of 112 minutes. In each case, the patient's lungs were used as the oxygenator. An average of 3.7 bypass grafts per patient were constructed. The left internal mammary artery was used in 41 patients, whereas at least one coronary endarterectomy was required in 20. Six patients had concomitant placement of an automatic implantable cardioverter defibrillator. Two patients (4.6%) died: 1 (with preoperative cardiogenic shock) of low cardiac output on postoperative day 1, and 1 of a severe neurologic deficit on day 8. Follow-up ranged from 2 to 18 months (average, 8.9 months), with all survivors demonstrating improvement in cardiac function in both the early and late postoperative periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Comorbidity↗
PubMed1992

Multicenter clinical evaluation of the HeartMate 1000 IP left ventricular assist device.

The Thermo Cardiosystems Inc (Woburn, MA) HeartMate 1000 IP left ventricular assist device (LVAD) has been evaluated as a bridge to transplantation in 34 patients for up to 324 days at seven clinical centers in the United States. Sixty-five percent of the patients underwent transplantation, 80% of whom were discharged from the hospital. Six additional control patients, transplant candidates who met the entrance criteria but who did not receive the device, were also included in the study. Although 3 (50%) of the control patients received transplants, all 6 died within 77 days of having met the LVAD inclusion criteria (100% mortality). Complications resulting from use of the device were comparable with those previously reported for all ventricular assist devices, except for thromboembolic events: bleeding, 39%; infection, 25%; and right heart failure, 21%. No device-related thromboembolic events occurred, although 1 patient experienced an event related to a mechanical aortic valve in the native heart. None of the complications had a significant negative association with outcome of the patient except for right heart failure. All survivors had a significant improvement in hepatic function before transplantation. Total bilirubin values were reduced by 60% during LVAD support. No significant differences were observed when total bilirubin values were compared at 30 and 60 days after LVAD support and at 30 and 60 days after transplantation in a cohort of 15 patients (p greater than 0.05). The improvement in renal function was less predictable than that of hepatic function. Creatinine values decreased significantly before transplantation; however, the values measured at 30 and 60 days after transplantation were higher than those measured at the same intervals after LVAD support had been initiated, and this increase is presumably related to the immunosuppressive drugs. In conclusion, the HeartMate 1000 IP LVAD has been shown to be effective in supporting end-stage cardiomyopathy patients to transplantation. Thromboembolism, previously regarded as a serious complication with such devices, has not been a problem with this device. Additional patients are being enrolled into the study to further document the safety and effectiveness of this technology.

Adolescent↗
PubMed1992

True aneurysm of the saphenous vein graft stump associated with CABG in a cardiac transplant patient.

Aneurysm of a saphenous vein graft after coronary artery bypass requires surgical resection because of its potential for rupture. This report describes a case of aneurysm formation in a 55-year-old man who underwent coronary artery bypass operation in 1977 and orthotopic heart transplantation 7 years later. A proximal vein graft remnant that had been ligated at the time of transplantation developed into a 5-cm aneurysm. In patients who have undergone previous coronary artery bypass operation, we recommend that the entire vein graft stump be excised and oversewn at the aortosaphenous anastomosis at the time of transplantation.

Aneurysm↗
PubMed1992

Preoperative and postoperative Hemopump support for patients undergoing orthotopic heart transplantation.

The Hemopump (Johnson & Johnson Interventional Systems, Rancho Cordova, CA) can be used successfully as a bridge to cardiac transplantation in patients with advanced cardiogenic shock that proves to be irreversible. Some patients, however, may also benefit from maintaining Hemopump support for a period of time after transplantation. A technique has been developed for continuing Hemopump support after transplantation that does not require repositioning of the device.

Adult↗
PubMed1992

Hyperlipidemia after heart transplantation: report of a 6-year experience, with treatment recommendations.

Mean plasma lipid values in 100 patients who survived greater than 3 months after heart transplantation increased significantly at 3 months over pretransplantation values: total cholesterol from 168 +/- 7 to 234 +/- 7 mg/dl, low density lipoprotein (LDL) cholesterol from 111 +/- 6 to 148 +/- 6 mg/dl, high density lipoprotein (HDL) cholesterol from 34 +/- 1 to 47 +/- 1 mg/dl and triglycerides from 107 +/- 6 to 195 +/- 10 mg/dl. There were no significant increases after this time. The LDL cholesterol values reamined greater than or equal to 130 mg/dl in 64% of patients and triglyceride values remained greater than or equal to 200 mg/dl in 41% of patients 6 months after postoperative dietary instructions. Beginning in 1985, select patients whose total cholesterol values remained greater than 300 mg/dl despite 6 months of dietary intervention were treated with lovastatin given alone in a high dose (40 to 80 mg/day) or in combination with another hypolipidemic agent. Four of the five patients so treated developed rhabdomyolysis; two of the four had acute renal failure. Beginning in 1988, a second protocol--lovastatin at 20 mg/day as monotherapy--was used in patients who despite dietary intervention had total cholesterol greater than 240 mg/dl (mean follow-up 13 months). In the 15 patients so treated, mean total cholesterol decreased from 299 +/- 10 mg/dl before treatment with lovastatin to 235 +/- 9 mg/dl during treatment (21% reduction, p less than 0.001) and mean LDL cholesterol was reduced from a baseline value of 190 +/- 10 to 132 +/- 12 mg/dl during treatment (31% reduction, p less than 0.001). In this study, lovastatin at a dose of less than or equal to 20 mg/day as monotherapy was a well tolerated, effective treatment for hyperlipidemia after heart transplantation. It did not result in rhabdomyolysis and required no alteration in immunosuppressive therapy. However, the dose should not exceed 20 mg/day and combination therapy with either gemfibrozil or nicotinic acid should be avoided, even if the target LDL cholesterol value is not reached.

Analysis of Variance↗
PubMed1992

Intracavitary repair of ventricular aneurysm and regional dyskinesia.

Myocardial damage after infarction is a common sequela in patients with coronary occlusive disease. The extent of injury varies and may be localized or diffuse. Since March 1989, the authors have used a new surgical repair technique that employs an intracavitary patch of Dacron fabric or glutaraldehyde-treated pericardium to exclude the hypokinetic or fibrotic myocardial segment. An elliptical configuration preserves the contour and volume of the ventricular cavity. After securing the patch, the ventriculotomy is closed with a simple continuous suture. Through July 31, 1991, 136 patients underwent repair using this technique. Of these patients, 100 (group I) had neither sustained an acute myocardial infarction (within 30 days before surgery) nor had undergone previous cardiac surgery, whereas 36 (group II) had sustained an acute myocardial infarction or had undergone previous cardiac surgery. In group I, four (4%) died within 30 days of surgery, and seven died later, resulting in a 6-month survival of 90.5% and a 1-year survival of 85.3%. In group II, 11 (30.6%) died within 30 days of surgery, and three died later. Functional class improved after repair in 95.7% of patients in group I and all patients in group II. In both groups, ejection fraction improved significantly (p less than 0.0001, group I; p less than 0.0001, group II). By eliminating the need for epicardial buttresses to repair the ventriculotomy, myocardial revascularization has been possible in most patients. This method of intraventricular repair is also appropriate for patients with calcified aneurysms, acquired ventricular septal defects, and acute ventricular rupture.

Bioprosthesis↗
PubMed1992

Implantation technique for the HeartMate left ventricular assist device.

The technique for implanting the HeartMate, an intraabdominally placed, pulsatile left ventricular assist device, is described. This device, which has been developed for potential use in patients requiring permanent left ventricular assistance, is currently undergoing clinical investigation in patients requiring temporary support as they await cardiac transplantation. This clinical experience has demonstrated device safety and efficacy, even for patients requiring extended periods of support.

Abdomen↗
PubMed1992

Recovery of pulmonary function in patients undergoing extended left ventricular assistance.

Heart transplantation should follow the implantation of a left ventricular assist device (LVAD) only after optimal postoperative recovery of pulmonary function. We reviewed hospital records of 12 patients who underwent extended (greater than 30 days) left ventricular support before transplantation to determine the rate of return of pulmonary function. The mean cardiac index and pulmonary capillary wedge pressure returned to normal in all patients within three days after LVAD implantation. The mean pulmonary artery pressure and pulmonary vascular resistance decreased but did not return to normal. The mean central venous pressure remained elevated throughout the first month but decreased by the time of transplantation. Supplemental oxygen requirements and peak airway pressures improved, and ten of the 12 patients were extubated by the fifth postoperative day. Preoperative roentgenographic evidence of pulmonary edema was present in eight patients, and pulmonary hilar prominence was present in the remaining four patients. Roentgenographic resolution of the pulmonary edema occurred slowly, persisting for one week after surgery in seven of eight patients. Ten patients were able to exercise strenuously 30 days after surgery, and 11 were returned to excellent condition before undergoing heart transplantation. Although the hemodynamic status in these patients significantly improved shortly after LVAD implantation, optimal recovery of pulmonary function required several weeks. Therefore, we advocate delaying transplantation after LVAD implantation to allow optimal pulmonary recovery.

Adult↗
PubMed1992

Management of patients supported on the Hemopump cardiac assist system.

The Hemopump Cardiac Assist System is a relatively new intraarterial, axial-flow circulatory assist device that offers temporary left ventricular support to patients in refractory cardiogenic shock, without requiring major surgery for insertion. Use of the Hemopump is associated with a low complication rate. Device-related morbidity is extremely rare. Because the Hemopump is safe for use in community hospitals, the number of patients supported by this device is expected to increase. In this report, we present general guidelines for the care of patients supported by the Hemopump. We describe techniques for the management of afterload reduction, supravalvular dislodgement, device malfunction, ventricular ectopy, intracardiac shunting, and inflow cannula obstruction.

Journal Article↗
PubMed1992

Clinical evaluation of right ventricular function in patients with left ventricular assist device (LVAD).

Right ventricular function (RVF) during LVAD support can be a threat for patient survival. Despite extensive research, RVF and its interference with left heart function is unclear. This study examines RVF in a retrospective analysis of 14 patients. Hemodynamic data were collected, including heart rate (HR), central venous pressure (CVP), mean pulmonary artery pressure (mPAP), total cardiac output (CO), calculated stroke volume index (SVI) and right ventricular stroke work index (RVSWI). In all patients, CO increased gradually throughout the study period; CVP showed no significant decrease; mPAP and PCWP decreased significantly over the time period; SVI improved and RVSWI increased from the starting level prior to implantation of the LVAD. We conclude that the CO improved with a lowering of the right ventricular afterload combined with a decrease in total circulating volume. The improvement of RVF with LV assist makes this device an option as a bridge to transplant.

Blood Pressure↗
PubMed1991

Treatment of cardiogenic shock with the Hemopump left ventricular assist device.

A multiinstitutional study is in progress to evaluate the Hemopump in the treatment of cardiogenic shock. Fifty-three patients with refractory cardiogenic shock were selected for Hemopump assistance. The hemodynamic definition of cardiogenic shock included (1) a cardiac index of less than 2.0 L.min-1.m-2, (2) pulmonary capillary wedge pressure of greater than 18 mm Hg, and (3) a systolic blood pressure of less than 90 mm Hg or a left ventricular work index of less than 1,500 g-m.m-2.min-1. The Hemopump was successfully inserted in 41 of 53 patients (77.3%). A significant improvement in the hemodynamic status was seen during Hemopump assistance. A minimal level of hemolysis was observed. No leg ischemia was observed. The 30-day overall survival of the Hemopump group was 31.7%. Criteria establishing indications for use and clinical utility are proposed. We conclude that the Hemopump provides significant hemodynamic support of the patient in cardiogenic shock allowing for recovery from ventricular stunning in marginal ventricles, and that in select patients the Hemopump may offer a major improvement in survival over conventional therapy.

Cardiac Output↗
PubMed1991

Myocardium-sparing cannulation technique for left ventricular assist device support.

The left atrium and the left ventricular apex are the most commonly used sites of inflow cannulation for postcardiotomy left ventricular support. A new cannulation technique that requires only an ascending aortotomy is introduced. This procedure can be undertaken with equipment present in any cardiac operating room and may prove to cause fewer complications than conventional cannulation techniques.

Aorta↗
PubMed1991

Primary cardiac sarcomas.

In marked contrast to benign cardiac tumors, primary cardiac sarcomas occur infrequently. Moreover, there is no uniform approach to treating such patients, and the benefits of postoperative chemotherapy are unclear. Between 1964 and 1989, 21 patients with primary cardiac sarcomas underwent surgical resection alone (n = 7), chemotherapy alone (n = 1), or combined operation and postoperative chemotherapy based on adriamycin (n = 13). Twenty-four operations were performed on 20 patients with relief of symptoms in all. Eleven patients had complete resection. Operative mortality was 8.3% (2/24). Histology and originating chamber(s) included angiosarcoma (n = 7; 6/7 in right atrium, 1 in left atrium), malignant fibrous histocytoma (7; all in left atrium), fibrosarcoma (2; 2/2 in left atrium), rhabdomyosarcoma (2; 1 in left atrium, 1 in right ventricle), leiomyosarcoma (2; 1 in left atrium, 1 in left ventricle); and one undifferentiated sarcoma (right atrium). Overall actuarial survival was 14% at 24 months after resection. Patients with complete resection had a median survival of 24 months compared with only 10 months in all other patients (p = 0.035). Postoperative chemotherapy did not enhance survival in patients with incomplete resection. At this time, aggressive and complete surgical resection seems to offer the best hope for palliation and survival in an otherwise fatal disease.

Adolescent↗
PubMed1991

Patent foramen ovale: a cause of hypoxemia in patients on left ventricular support.

We describe 2 patients who experienced right-to-left shunting during support with a left ventricular assist device as a result of patent foramen ovale. In the first patient, the patent foramen ovale was not found until autopsy. In the second patient, fluctuations in continuous mixed venous oxygen saturations caused us to suspect a patent foramen ovale, which was confirmed with transesophageal contrast echocardiography. We promptly repaired the defect and this patient survived. When patients on assist devices experience unexplained arterial hypoxemia, a patent foramen ovale should be considered. If a patent foramen ovale is found, surgical correction should be done early.

Adult↗