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Biomedical subjects

L E Samuels

Publications and source records attributed to L E Samuels.

At least 19 recordsLinked to original sources

Mechanical circulatory support for acute heart failure.

Circulatory support devices are frequently required in postcardiotomy shock, postmyocardial infarction shock, and acute myocarditis. A panel of cardiac surgeons addressed the use of these devices in 4 patients. Cardiogenic shock after mitral valve replacement was considered best served by a left ventricular assist device (VAD) with apical rather than atrial cannulation. A left VAD should be placed first and a right VAD only if needed. Acute myocardial infarction shock was considered best treated with a left VAD with left ventricular cannulation to avoid thrombosis. If cardiac transplantation is an option, a long-term device must be considered. Young patients with acute fulminant myocarditis should be implanted with VADs in anticipation of recovery, and transplantation should be delayed. Patients with severe heart failure after coronary bypass grafting were considered best served by an extracorporal membrane oxygenation (ECMO) system or a VAD. Current postcardiotomy survival rates of postcardiotomy patients of 20% to 40% are worthwhile, but can be improved. Temporary devices such as ECMO can be changed to more long-term devices when necessary.

Acute Disease↗

Management of acute cardiac failure with mechanical assist: experience with the ABIOMED BVS 5000.

BACKGROUND: Mechanical circulatory assist industries have developed ventricular assist devices (VAD) for short-, intermediate-, and long-term use. The purpose of this report is to describe the progress made with the ABIOMED Biventricular System (BVS) 5000 (ABIOMED, Inc, Danvers, MA) short-term VAD. METHODS: From June 1994 through August 2000, all cardiogenic shock patients who required short-term mechanical assist were supported with the ABIOMED BVS 5000. Insertion criteria included any condition that may potentially result in cardiac recovery. A formal algorithm for timing of insertion was established to standardize implantation criteria. RESULTS: A total of 45 patients were supported at Hahnemann University Hospital, Philadelphia, PA. There were 26 male and 19 female patients, with a mean age of 57.9 years (range 33 to 80 years). Devices were inserted for postcardiotomy shock in 36 patients (80%) and precardiotomy shock in 9 patients (20%). The average duration of support was 8.3 days (range 1 to 31 days). Overall, there were 22 (49%) patients weaned from support and 14 (31%) discharged from the hospital. For patients in whom the device was implanted in accordance with an established protocol (group A), the wean and discharge rates were 60% and 43%, respectively. The most common morbidities included bleeding and adverse neurologic events. CONCLUSIONS: The ABIOMED BVS 5000 VAD continues to be a valuable form of short-term mechanical assist for acute cardiogenic shock. The formation of a uniform VAD insertion algorithm has helped to standardize protocols in management.

Acute Disease↗

Annexin-V imaging for noninvasive detection of cardiac allograft rejection.

Heart transplant rejection is characterized pathologically by myocyte necrosis and apoptosis associated with interstitial mononuclear cell infiltration. Any one of these components can be targeted for noninvasive detection of transplant rejection. During apoptotic cell death, phosphatidylserine, a phospholipid that is normally confined to the inner leaflet of cell membrane bilayer, gets exteriorized. Technetium-99m-labeled annexin-V, an endogenous protein that has high affinity for binding to phosphatidylserine, has been administered intravenously for noninvasive identification of apoptotic cell death. In the present study of 18 cardiac allograft recipients, 13 patients had negative and five had positive myocardial uptake of annexin. These latter five demonstrated at least moderate transplant rejection and caspase-3 staining, suggesting apoptosis in their biopsy specimens. This study reveals the clinical feasibility and safety of annexin-V imaging for noninvasive detection of transplant rejection by targeting cell membrane phospholipid alterations that are commonly associated with the process of apoptosis.

Adult↗

Coronary artery disease in identical twins.

The incidence of coronary artery disease in identical twins is unknown. The knowledge of ischemic heart disease in this patient population is represented by case reports. There is considerable controversy regarding the environmental and genetic factors that play a role in the pathogenesis of this disorder. The natural history of coronary artery disease in an asymptomatic twin with a symptomatic counterpart is unclear. We present a case report and literature review of coronary artery disease in identical twins. On the basis of our patient and the information of other patients, asymptomatic twins of symptomatic counterparts require aggressive assessment and management for occult coronary artery disease.

Aged↗

Open heart surgery in patients with chronic lymphocytic leukemia.

BACKGROUND: Chronic leukemia is a disease characterized by the malignant proliferation of immunologically incompetent lymphocytes. The knowledge of open heart surgery in patients with this disorder is limited. METHODS: Twelve patients with chronic lymphocytic leukemia underwent open heart surgery (nine coronary artery bypass grafting (CABG), two aortic valve replacement (AVR), one CABG and AVR) from September 1991 to September 1996. There were nine males and three females with a mean age of 68 years (41-81 years). Staging was assigned according to the Rai Classification. There were seven Stage 0, two Stage I, zero Stage II, one Stage III and two Stage IV patients. Cardiopulmonary bypass (CPB) was performed using standard techniques of cannulation, moderate hypothermia and antegrade/retrograde cardioplegia. RESULTS: Hospital mortality occurred in two (17%) patients. Both patients died of sepsis. Hospital morbidity occurred in seven (58%) patients. The most common complications were infections. Five patients were found to have other malignancies (basal cell, laryngeal, prostate, bladder and breast cancers). Transfusion of blood products was required in eight (67%) patients. The average length of stay was 15 days (7-50 days). Follow-up was complete. Late mortality occurred in four patients at a mean of 7 months (1-18 months). All deaths were non-cardiac related (ruptured AAA, kidney failure, respiratory failure and sepsis). Six patients remain alive at a mean of 25 months (1-48 months). CONCLUSION: Hospital mortality and morbidity in patients with chronic lymphocytic leukemia undergoing open heart surgery are high. Infection is the leading cause of hospital death, as well as the most common complication. The majority of patients receive blood products during the course of their hospitalization. Late mortality is high and non-cardiac related. Based on these findings, a re-definition of the aims, goals and expectations of open heart surgery in patients with chronic leukemia is necessary. Suggestions in management are presented.

Aged↗

Coronary artery bypass surgery in nonagenarians.

As the number of nonagenarians increases yearly in the United States, surgeons will be asked more often to evaluate the possibility of intervention for coronary artery disease in this age group. The purpose of this study is to document experience with patients 90 years of age or older in order to determine whether coronary artery bypass grafting surgery is justified. Eleven patients aged 90 years or more underwent cardiac surgery for symptomatic coronary artery disease refractory to medical management between January 1, 1987, and December 31, 1996. All patients were in NYHA Class IV preoperatively. In-hospital death occurred in two patients (18%). In-hospital morbidity occurred in all patients (100%) including seven cardiac, four respiratory, two neurologic, and one infectious. All survivors left the hospital symptomatically improved. The mean length of stay was 28 days. Four patients died at a mean of 2 years and 2 months postoperatively. Five patients remain alive at a mean of 1 year and 7 months. Coronary artery bypass grafting in nonagenarians can be performed successfully in selected cases. However, increased mortality and morbidity rates and length of stay are associated with this age group. For survivors, the quality of life is improved and the projected life expectancy restored.

Aged↗

Surgical treatment of interventional coronary angiographic accidents.

Newer methodologies have increased the incidence of coronary interventions. At the authors' institution, 5,614 coronary interventional procedures (28% of all catheterizations) were performed over a 3-year period, from 1995 to 1997. Eighty-one patients (1.4%) suffered angiographic accidents, including coronary artery dissection, free rupture, tamponade, foreign body embolism, and wire entrapment, and were retrospectively reviewed. All patients were taken for emergency surgery in less than 4 hours. The mean age was 61.2 years, 44 (54%) were men, and 37 (46%) were in cardiogenic shock at the time of surgery. Fifty-seven patients (70%) had intraaortic balloon counterpulsation. The number of previous cardiac interventions ranged from one to four with a mean of 1.9. One to five bypass grafts (mean, 2.2) were performed, and three patients required temporary ventricular assist devices. There were six deaths for a 30-day mortality rate of 7.4%. Thirty-two patients (39.5%) suffered significant morbidity, including cerebrovascular accidents, and renal and respiratory failure. Perioperative myocardial infarctions were diagnosed in 39 (48%) patients. Average length of stay was 12.1 days. One-year survival was satisfactory at 90% (73/81), with 56 survivors (77%) regaining normal everyday activity. Early surgical intervention, rapid revascularization, and temporary mechanical support are keys to low mortality in this high-risk group. Identification of high-risk interventions and significant comorbid conditions, with concomitant surgical consultation, need to be pursued to reduce the high morbidity rate.

Activities of Daily Living↗

Diagnosis and management of traumatic aorto-right ventricular fistulas.

BACKGROUND: Traumatic aorto-right ventricular (Ao-RV) fistulas are rare lesions that result in congestive heart failure if left untreated. Early diagnosis and prompt surgical intervention are required to avoid the natural outcome of cardiac decompensation. METHODS: All cases of traumatic Ao-RV fistula described in the English literature since 1958 were reviewed. The clinical presentation, methods of diagnosis, and treatment strategies were assessed to determine the pathophysiology, natural history, and outcome of surgical intervention. RESULTS: Forty cases of traumatic Ao-RV fistulas were described in the English literature. There were 39 men and 1 woman, with a mean age of 28.3 years (range, 15 to 50 years). Twenty-two (55%) patients had isolated Ao-RV fistulas. Fourteen (35%) had Ao-RV fistulas with aortic insufficiency. Definitive surgical repair was performed in 38 patients. The associated aortic valve injuries were managed with repair techniques or replacement with prosthetic devices. The surgical outcomes in all patients were satisfactory. CONCLUSIONS: The pathophysiology and natural history of Ao-RV fistulas involves the development of congestive heart failure. Traumatic aortic insufficiency frequently is associated with this disorder. Early diagnosis and prompt treatment are necessary to avoid the natural outcome of cardiac decompensation. Definitive repair should be performed with the aid of cardiopulmonary bypass during the same hospitalization.

Adolescent↗

Total simultaneous repair of coarctation and intracardiac pathology in adult patients.

BACKGROUND: Thoracic aortic coarctation accompanied by a second surgically reparable lesion is a rare combination in the adult patient. The simultaneous operative management of both lesions is desirable because of the higher morbidity and mortality that would occur with staged procedures. METHODS: We describe the simultaneous operative management in three adult patients with coarctation and a second cardiac lesion. All 3 patients had intrapericardial ascending aorta-descending aorta bypass and concomitant repair of a cardiac lesion. The attendant repairs in the 3 patients, respectively, were aortic valve replacement, orthotopic heart transplantation, and coronary artery bypass grafting. RESULTS: Double arterial cannulation, retrograde cardioplegia, large-bore aorto-aortic bypass grafts, and early use of alpha-agonists to stabilize systemic pressure were all key to ensuring safe conduct of the operation. Each patient had an essentially uneventful postoperative course. CONCLUSIONS: Thoracic coarctation and concomitant cardiac pathology can be safely and readily managed with a single-stage approach involving cardiac repair and extraanatomic ascending aorta-descending aorta bypass grafting. A review of the English-language literature of patients managed similarly is included.

Adrenergic alpha-Agonists↗

Minimally invasive saphenous vein harvesting.

BACKGROUND: Minimally invasive techniques to harvest the saphenous vein for coronary artery bypass grafting continue to improve and evolve. Smaller cutaneous incisions have been shown to decrease postoperative discomfort and improve healing. We describe a technique involving carbon dioxide insufflation and endoscopic dissection to allow easier and atraumatic dissection. METHODS: The VasoView endoscope system (Origin Medsystems, Inc) was used to harvest the saphenous vein for coronary artery bypass grafting in 27 patients. This group was compared with 24 patients having traditional saphenous vein harvesting. Wounds were examined for complications daily. Pain and postoperative mobility were quantified independently by physical therapists. RESULTS: Comparison of patients in the two groups revealed greater edema in the legs with traditional harvesting. Patients with endoscopic removal also had less pain and increased mobility postoperatively. On average, minimally invasive harvesting allowed patients to ambulate to a predischarge goal of 300 ft 2 days earlier. CONCLUSIONS: Minimally invasive harvesting of the saphenous vein by insufflation techniques is safe, effective, and atraumatic to the conduit. Discomfort is minimized, promoting earlier and improved ambulation.

Aged↗

Temporary epicardial atrial pacing electrodes: duration of effectiveness based on position.

BACKGROUND: To investigate the duration of effectiveness in the postoperative period of temporary epicardial atrial pacing electrodes on the right atrium, based on position. METHODS: The function of temporary epicardial atrial pacing electrodes were examined in 55 patients undergoing coronary artery bypass grafting from March 20, 1996, to July 31, 1996, at Allegheny University Hospitals, Hahnemann Division, Philadelphia, PA. There were 41 male and 14 female patients. The mean age was 71 years (range 35 to 86 years). Two atrial and two ventricular temporary epicardial pacing electrodes were placed at the termination of cardiopulmonary bypass. One atrial electrode was placed on the body of the right atrium at the junction of the superior vena cava (body electrode); the other was passed through the pursestring of the atrial cannulation site (appendage electrode). RESULTS: The mean thresholds for the atrial body electrodes on the operative day and postoperative days 1 and 2 were 4.96, 6.67, and 6.80 mA, respectively. The mean thresholds for the atrial appendage electrodes were 5.98, 7.50, and 8.59 mA, respectively. CONCLUSIONS: Temporary epicardial atrial pacing electrodes are more effective when the wires are placed in the atrial body of the right atrium than if they are wrapped within the pursestring of the right atrial appendage. As a result of these findings, the common practice of placing the pacing wire through pursestring tissue should be abandoned.

Adult↗

Amiodarone-associated hemoptysis.

Amiodarone is a benzofuran derivative with a chemical structure similar to thyroxine. Originally introduced to treat angina pectoris, amiodarone was found to have antiarrhythmic properties, and in 1985, was approved in the United States for treatment of life-threatening ventricular arrhythmias. It is now used for various ventricular and supraventricular arrhythmias refractory to conventional first-line medications, and as a result, side effects have been observed with increased frequency. The most severe and potentially life-threatening of these side effects is the development of pulmonary toxicity. Typically, amiodarone pulmonary toxicity (APT) is manifested by acute pneumonitis and chronic fibrosis. Amiodarone-associated hemoptysis (AAH) is a rare occurrence. The authors describe a case of AAH successfully treated with cessation of drug and steroid therapy.

Amiodarone↗

Coronary artery bypass grafting in patients with COPD.

OBJECTIVE: To more fully define the influence of COPD in patients undergoing coronary artery bypass grafting (CABG). METHODS: One hundred ninety-one patients with COPD underwent CABG from March 1, 1995, to June 21, 1996. There were 129 male and 62 female patients. The mean age was 69 years (45 to 86 years). Patients with COPD were defined according to the Summit Database definition: requires therapy for the treatment of chronic pulmonary compromise or has an FEV1 <75% of predicted value. RESULTS: Hospital mortality was 7%. Hospital morbidity was 50%. Statistically significant (p<0.05) morbidity included general pulmonary complications (12%) and atrial fibrillation (27%). Hospital mortality for COPD patients with postoperative pneumonia was 11%. Hospital mortality for patients with COPD receiving steroids was 19%. The hospital mortality for patients > or = 75 years of age was 17%. The combined mortality for patients with COPD who are > or = 75 years of age and receiving steroid therapy was 50%. The mean length of stay was 12 days. Late mortality was 1% at a mean of 1.5 years. CONCLUSIONS: Hospital mortality in most patients with mild-to-moderate COPD undergoing CABG is similar to those without COPD. In the minority of patients with severe COPD who are receiving steroids and > 75 years, the hospital mortality is exceptionally high. These findings support CABG in patients with mild-to-moderate COPD. Nonsurgical therapy should be considered for elderly COPD patients with severe disease taking steroids.

Aged↗