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Biomedical subjects

Louis E Samuels

Publications and source records attributed to Louis E Samuels.

At least 19 recordsLinked to original sources
PubMed2006

Cognitive dysfunction in advanced heart failure and prospective cardiac assist device patients.

BACKGROUND: Extended periods of hypoperfusion in an advanced heart failure (HF) places patients at high risk for neurobehavioral compromise, which has not been studied systematically. It is also not clear how intravenous inotropic therapy and mechanical cardiac assist devices (MCAD) affect cognitive function. METHODS: This prospective cross-sectional cognitive preliminary study evaluated 252 potential heart transplant candidates assessing functions in memory, motor, and processing speed. Patients were divided into three HF groups based on severity of disease: group 1 outpatients (n = 113), group 2 in-patients requiring inotropic infusion (n = 83), and group 3 inpatients likely requiring MCAD support (n = 56). Aggregate z-scores for memory, motor, and processing speed and independent samples t tests assessed intergroup differences on 13 cognitive measures. RESULTS: A broad pattern of cognitive impairment was observed within the advanced HF group; fewer deficits were found in group 1 outpatients and more severe deficits in group 3 MCAD subjects. A difference in motor functions was observed as the earliest abnormality, with group 3 showing significant changes compared with group 1. The most dramatic changes were seen in domain mental processing speed along with specific verbal and visual memory functions, which were slower in group 3 compared with groups 1 and 2. CONCLUSIONS: Cognitive deficits are common in advanced HF and worsen with increasing severity of HF. Appropriately designed and randomized studies will be needed to demonstrate if earlier MCAD implantation is warranted to arrest cognitive dysfunction and better postimplantation adaptation.

Adult↗
PubMed2006

Outcome improvement and cost reduction in an increasingly morbid cardiac surgery population.

Two studies assessed initiatives to improve the quality and the cost-effectiveness of cardiac surgery. The first evaluated a system for access and stabilization (SAS), with coronary stabilization, and a clinical effectiveness quality initiative (CEQI) in off-pump coronary artery bypass grafting. The SAS + CEQI cohort showed significantly lower mortality, a lower percentage of patients requiring prolonged ventilation, and a shorter mean postoperative length of hospital stay than the pre-SAS cohort who underwent on-pump coronary artery bypass grafting. The second study assessed the potential for noninvasive cerebral oximetry to reduce strokes related to all cardiac surgery by optimizing cerebral oxygen delivery. The incidence of permanent stroke was significantly lower in the cerebral oximetry group than in an earlier control group in which cerebral oximetry was not used, despite the fact that the study group had a significantly greater number of patients in New York Heart Association classes III and IV. The proportion of patients requiring prolonged ventilation was significantly lower, and the length of postoperative hospital stay was significantly shorter in the study group than in the control group. The incidence of cerebrovascular accident in the study group was 0.97%, compared with 2.03% in the controls. This translated to a potential avoidance of 12 cerebrovascular accidents and approximately $254,214 in direct costs and more than $425,000 in total costs. The results show that specific measures can improve outcomes and reduce costs in cardiac surgery. Therefore, the use of a clinical effectiveness quality initiative and cerebral oximetry in all cardiac surgery, with the SAS system for off-pump surgery, should be advocated.

Coronary Artery Bypass, Off-Pump↗
PubMed2006

The Thoratec Implantable Ventricular Assist Device (IVAD): initial clinical experience.

BACKGROUND: The Thoratec Implantable Ventricular Assist Device (IVAD) is the only FDA-approved intracorporeal biventricular cardiac assist device. It is a titanium-coated version of its predecessor, the Paracorporeal Ventricular Assist Device (PVAD). The blood pump is compatible with the portable TLC-II driver, making home discharge feasible. METHODS: Nine consecutive patients were implanted with the IVAD from June 2005 through March 2006. The indications for support were acute heart failure in 6 cases and chronic heart failure in 3 cases. All patients were managed with maximal medical therapies including intravenous inotropic drugs prior to implant. RESULTS: All patients survived the surgical implant. Six patients were considered successful: 3 patients discharged to home and subsequently received transplantation, 2 are awaiting transplantation (1 at home and 1 in-house), and 1 patient was successfully explanted. Three patients expired postoperatively because of multiple organ system failure (2 patients) and pulmonary hemorrhage (1 patient). There were no device malfunctions. There was 1 localized driveline site infection and 1 thromboembolic event with partial visual loss. CONCLUSIONS: The IVAD is a unique device capable of providing uni- or bi-ventricular support for either acute or chronic heart failure conditions. Its versatility permits bridge to transplant or recovery options. Home discharge is feasible.

Adult↗
PubMed2005

Selective use of amiodarone and early cardioversion for postoperative atrial fibrillation.

BACKGROUND: Postoperative atrial fibrillation (AF) occurs in 20%-40% of patients undergoing open-heart surgery. Numerous pharmacological and electrical therapies have been used as a prophylaxis to prevent this dysrhythmia. The purpose of this study was to examine the selective use of amiodarone and early cardioversion (CVN) postoperatively to restore normal sinus rhythm (NSR). METHODS: A retrospective nonrandomized review of patients who received amiodarone and early electrical CVN (study group) for postoperative AF after coronary artery bypass grafting (CABG) were compared with patients who received nonamiodarone therapies (control group). The study group received 150 mg of amiodarone bolus intravenously and thereafter received an infusion of 1 g over a 24-hour period. If NSR was established within 24 hours, then the intravenous (IV) infusion was continued for another 24 hours with concomitant oral amiodarone overlap. If NSR was not established within 24 hours, then external electrical CVN was performed. After 48 hours, the IV infusion was discontinued and the oral regimen maintained through discharge. Control group patients received either combination digoxin and procainamide or diltiazem. Postoperative beta-blocker administration was instituted in all patients. RESULTS: Six-hundred forty consecutive CABG patients were examined between July 1995 and June 2003. Postoperative AF developed in 160 of these patients (25%). One-hundred patients constituted the study group and 60 patients represented the control group. Restoration of NSR within 24 and 48 hours occurred in 79 (79%) and 90 patients (90%) for the study group, respectively, compared with 38 (64%) and 44 patients (73%) for the control group, respectively. The presence of NSR at discharge was achieved in 98 study patients (98%) and 50 control patients (83%). The length of stay (LOS) for the study and control patients was 7.4 and 9.1 days, respectively. There was no mortality in either group. CONCLUSIONS: Amiodarone and early CVN was more effective than nonamiodarone therapies with regard to restoring NSR for patients in whom AF developed after elective CABG. A trend toward a decrease in LOS was observed in the study group, but was not statistically significant. The overall LOS using amiodarone therapy with early CVN was similar to postoperative AF for patients in whom the condition did not develop.

Administration, Oral↗
PubMed2005

Initial experience with the Abiomed AB5000 ventricular assist device system.

PURPOSE: We describe our initial experience with the Abiomed AB5000 ventricular assist device (VAD). DESCRIPTION: The Abiomed AB5000 VAD is a system recently approved by the Food and Drug Administration that consists of a fully automatic, vacuum-assisted console and a paracorporeal, pneumatically driven blood pump. The VAD is designed for short or intermediate term use. The console is designed to support the BVS5000 or AB5000 blood pumps. The cannulas and implantation are similar to the BVS5000 system. EVALUATION: Four cases are described in which two AB5000 systems were placed de novo and two were transitioned from previously placed BVS5000 units. Hemolysis was observed in 2 cases. The AB5000 VAD flows were generally 4.0 to 4.5 L/min, approximately 0.5 L/min less than the BVS5000. Echocardiography demonstrated high-velocity jets from the inflow cannula in the 2 hemolysis cases. One patient died of multiorgan system failure while on support, 2 were successfully weaned from support and transferred to long-term care facilities, and 1 was weaned from support and successfully discharged to home. CONCLUSIONS: The AB5000 VAD is a versatile paracorporeal pneumatic VAD that can be placed de novo or transitioned from a previously placed BVS5000 unit without the need for additional surgery. Lower outputs, high-velocity jets, and hemolysis were observed in 2 of 4 cases. Modifications in cannulas design and placement as well as console reconfigurations may be necessary to optimize performance.

Aged↗
PubMed2005

Surgical resection of a lupus-related left ventricular aneurysm in a patient with normal coronary arteries: case report.

A 52-year-old woman with systemic lupus erythematosus (SLE) presented with shortness of breath. Echocardiography and cardiac catheterization demonstrated a discrete left ventricular aneurysm (LVA) with normal coronary arteries. Although her heart failure symptomatically improved with medical therapy, she suffered an embolic stroke from a thrombus within the LVA. She was treated with anticoagulation and rehabilitation for 6 weeks. Reevaluation with echocardiography demonstrated persistent depressed LV function and mural thrombus within the LVA. Surgical resection of the LVA was performed with evacuation of the thrombus and local repair of the LV.

Anticoagulants↗
PubMed2005

Malignant pericardial effusion--an uncommon complication of multiple myeloma: case report.

Multiple myeloma is a condition usually associated with lesions of the skeleton. However, under rare circumstances, the malignant plasma cells may infiltrate the pericardium, resulting in an effusion. If left untreated, the abnormal accumulation of pericardial fluid will result in cardiac tamponade, requiring drainage. The following report describes a multiple myeloma patient who developed secondary pericardial and pleural effusions, which were surgically drained via a pleuropericardial window.

Aged↗
PubMed2005

Videoscopic resection of a giant symptomatic pericardial cyst: case report.

A 47-year-old woman presented with shortness of breath, chest discomfort, and hoarseness. She was found to have an enlarged cardiac silhouette on plain chest radiography. Computed tomographic scan and magnetic resonance imaging were diagnostic of a giant pericardial cyst. The patient underwent successful videoscopic removal of the cyst with complete resolution of her symptoms.

Chest Pain↗
PubMed2004

Aneurysm of aortocoronary saphenous vein graft: case report and literature review.

True aneurysms of aortocoronary saphenous vein bypass grafts are a relatively rare complication of bypass surgery, but because the complications of thrombosis, embolization, or rupture are potentially fatal, this condition requires immediate surgical intervention. We describe a 78-year-old man who had undergone coronary bypass 15 years previously and who presented with a saphenous vein graft that was severely degenerated and aneurysmally enlarged throughout its course, measuring as much as 5 to 6 cm in certain locations. Redo coronary artery bypass grafting using the right and left internal thoracic arteries and resection of the aneurysm were performed. We also present a review of the literature regarding diagnosis, management, and treatment of this condition.

Aged↗
PubMed2004

Psychosocial and sexual concerns of patients with implantable left ventricular assist devices: a pilot study.

OBJECTIVE: We sought to determine the psychosocial and sexual concerns of patients discharged from the hospital with implantable left ventricular assist devices. METHODS: Bridge-to-transplant patients with the Heartmate left ventricular assist device received a psychosocial and sexual survey at 1 month after discharge from the hospital. The survey consisted of 3 parts, with 5 questions in each category. The patients were asked to complete the survey by circling the responses and to provide more detailed answers when necessary. RESULTS: There were 8 male patients who completed the questionnaire. Psychologically, all patients expressed a positive mood and found support from family or religious sources. The majority described a change in attitude and behavior. Socially, all patients described a change in lifestyle, as well as a change in the reaction of family and friends. No patient went back to work or had the desire to return to work until after transplantation. The minority of patients admitted to smoking or drinking. Sexually, the majority had the desire or participated in sexual activities. The majority of patients either used or were interested in using sexual stimulants. There were no mechanical problems with the left ventricular assist devices. CONCLUSIONS: Psychosocial and sexual conditions are altered in patients with heart failure who are discharged with implantable left ventricular assist devices. At 1 month's time interval, there is an improvement in mood, an adjustment in lifestyle, and a positive shift in relations with family and friends. There is sexual desire, with interest in sexual-enhancing medication. The most common concern is related to the pump, such as the durability of the device or damage to the components.

Adult↗
PubMed2004

Complications following placement or extraction of endovascular pacemaker and defibrillator leads--cardiothoracic surgical intervention: case reports.

Complications related to the insertion or removal of permanent pacemakers and implantable cardiac defibrillators are rare events. However, when adverse events occur, their severity may be life threatening. Rapid recognition of a problem followed by prompt consultation with a cardiothoracic surgeon is necessary to stabilize potentially catastrophic events. The immediate availability of surgical instruments as well as a formalized algorithm for management is necessary to control hemorrhagic situations. Four case reports illustrate these points.

Adult↗
PubMed2003

Total artificial heart: destination therapy.

The AbioCor is a revolutionary device. It is the only device of its kind in the clinical world. The role of the AbioCor is to provide permanent replacement of the failing heart for patients who are not transplant candidates. The clinical trial has been successful in the majority (four of seven) of patients implanted thus far. Eight more patients are required to complete the initial feasibility phase of the trial, afterwhich it remains to be seen if the trial will expand to additional patient populations. The powerful features of the pump have been demonstrated in the extremely sick group of candidates that enrolled in the study. The TET system has worked extremely well. Lastly, the milestone of discharging a patient to home on a completely internal artificial heart has been realized. The profile of CardioWest is very different from AbioCor. Although both were initially designed as permanent replacement therapies, the CardioWest has been extremely useful as a bridging device, and it may have a broader application in the future. For the CardioWest, the most favorable groups are patients with cardiomyopathy who decompensate while awaiting transplantation. On the other hand, the AbioCor is indicated in nontransplant candidates with biventricular failure who have a less than 30-day predicted survival. Proper patient selection is critical to achieving success with either device.

Equipment Design↗
PubMed2003

Management of acute cardiogenic shock.

The present state of the art in mechanical cardiac assist technology has permitted application of machines to a variety of conditions that confound the cardiologist and cardiac surgeon alike. Decades of research and development have allowed the present devices to be used as bridges to native heart recovery and bridges to transplantation. We are now entering the era in which devices are being placed for permanent assist or replacement. Although the acute cardiogenic shock patient remains problematic, we now have at our disposable a variety of tools that have enabled us to salvage more patients than ever before. The experience with these systems continues to grow, with leading centers and investigators contributing meaningful information toward the application and development of the latest technologies. It has been said that mechanical therapies precede biological therapies. We are at the crossroads in which a combination of biological therapies with mechanical therapies is underway. Current research is investigating the role of mechanical cardiac support while biological therapies are introduced into the failing heart. In the meantime, the role of mechanical cardiac assist and replacement has matured into an effective means of treating acute cardiogenic shock of any variety.

Acute Disease↗