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Biomedical subjects

J A Elefteriades

Publications and source records attributed to J A Elefteriades.

At least 19 recordsLinked to original sources
PubMed1997

Results of coronary artery bypass grafting by a single surgeon in patients with left ventricular ejection fractions < or = 30%.

Despite the ominous prognosis of severe left ventricular (LV) dysfunction from coronary artery disease, coronary artery bypass grafting (CABG) in this setting remains controversial because of concerns over high operative risk and low likelihood of functional or survival benefit. We analyzed 135 consecutive patients (113 men, 22 women; age 42 to 87 years, mean 66.5) with LV ejection fraction (EF) < or =30% undergoing isolated CABG by 1 surgeon over an 8-year period. LVEF ranged from 10% to 30% (mean 23.6%). Preoperatively, 63% of patients had angina, 61% had heart failure (23% with pulmonary edema), and 24% manifested severe ventricular arrhythmia. The mean number of grafts was 2.7 per patient. The internal mammary artery was used in 103 of the 120 grafts (86%) to the left anterior descending coronary artery. Seven patients (5.2%) died in hospital. Only 2 of 99 patients (2%) not in intensive care preoperatively died in hospital. Angina class improved by 2.0 categories and congestive heart failure class by 1.5 categories. LVEF (assessed in 104 of 128 hospital survivors) improved from 24% preoperatively to 34% postoperatively (p <0.0001). At 1, 3, and 4.5 years respectively, all-cause survival was 87%, 81%, and 71%, and freedom from cardiac death was 90%, 85%, and 80%. CABG in patients with coronary artery disease and advanced LV dysfunction: (1) can be performed relatively safely, (2) achieves good long-term survival, (3) improves LVEF, (4) improves quality of life, and (5) can safely utilize the internal mammary artery as a conduit. The use of CABG is encouraged for patients with advanced LV dysfunction and may provide a viable alternative to transplantation in selected patients.

Adult↗
PubMed1997

What is the appropriate size criterion for resection of thoracic aortic aneurysms?

Although many articles have described techniques for resection of thoracic aortic aneurysms, limited information on the natural history of this disorder is available to aid in defining criteria for surgical intervention. Data on 230 patients with thoracic aortic aneurysms treated at Yale University School of Medicine from 1985 to 1996 were analyzed. This computerized database included 714 imaging studies (magnetic resonance imaging, computed tomography, echocardiography). Mean size of the thoracic aorta in these patients at initial presentation was 5.2 cm (range 3.5 to 10 cm). The mean growth rate was 0.12 cm/yr. Overall survivals at 1 and 5 years were 85% and 64%, respectively. Patients having aortic dissection had lower survival (83% 1 year; 46% 5 year) than the cohort without dissection (89% 1 year; 71% 5 year). One hundred thirty-six patients underwent surgery for their thoracic aortic aneurysms. For elective operations, the mortality was 9.0%; for emergency operations, 21.7%. Median size at time of rupture or dissection was 6.0 cm for ascending aneurysms and 7.2 cm for descending aneurysms. The incidence of dissection or rupture increased with aneurysm size. Multivariable regression analysis to isolate risk factors for acute dissection or rupture revealed that size larger than 6.0 cm increased the probability by 32.1 percentage points for ascending aneurysms (p = 0.005). For descending aneurysms, this probability increased by 43.0 percentage points at a size greater than 7.0 cm (p = 0.006). If the median size at the time of dissection or rupture were used as the intervention criterion, half of the patients would suffer a devastating complication before the operation. Accordingly, a criterion lower than the median is appropriate. We recommend 5.5 cm as an acceptable size for elective resection of ascending aortic aneurysms, because resection can be performed with relatively low mortality. For aneurysms of the descending aorta, in which perioperative complications are greater and the median size at the time of complications is larger, we recommend intervention at 6.5 cm.

Adolescent↗
PubMed1997

Reduction ventriculoplasty for the cardiomyopathic heart: a case report.

A 44-year-old morbidly obese and hypertensive woman had been diagnosed with idiopathic cardiomyopathy seven years previously. She was referred for consideration for heart transplantation because of progression of symptoms to class IV. Massive obesity and pulmonary hypertension were strong relative contraindications to transplantation. During outpatient evaluation, the patient developed pulmonary edema, was hospitalized, and became intensive care unit-bound and immobile. Exercise radionuclide angiocardiography revealed left ventricular ejection fraction of 17%, and left ventricular end-diastolic volume of 408 mL. A reduction ventriculoplasty procedure was performed by resection of the lateral wall of the left ventricle. The patient did very well, and was discharged on postoperative day nine. Two weeks after the procedure, exercise radionuclide angiocardiography demonstrated left ventricular ejection fraction of 30% (76% increase) and left ventricular end-diastolic volume of 293 mL (28% decrease). The patient remains in stable New York Heart Association class II, now three months postprocedure. This initial positive experience in New England encourages-continued investigation of the reduction ventriculoplasty procedure, either as a bridge or as an alternative to heart transplantation in patients with dilated cardiomyopathy.

Adult↗
PubMed1997

Minimally invasive coronary artery bypass grafting: initial Connecticut experience.

We report the initial Connecticut experience with minimally invasive coronary artery bypass grafting. This procedure allows bypass grafting to the left anterior descending coronary artery utilizing the internal mammary artery as the conduit. The procedure is minimally invasive because it is performed through a mini-thoracotomy incision in the fourth anterior intercostal space and it is conducted without the use of cardiopulmonary bypass. The procedure has been applied to 13 patients operated between February and October 1996. All but one patient selected were poor candidates for conventional coronary artery bypass surgery because of advanced age (6), chronic renal failure/dialysis/kidney transplant (4), redo status with vulnerable grafts (1), severe peripheral vascular disease (6), severe chronic obstructive pulmonary disease (4). All patients survived operation and were discharged in good condition. Mean postoperative intubation time was seven hours and mean hospital stay was 4.5 days despite the very high pre-existing comorbidity of these patients. All patients are alive at the current follow-up time. Two patients required a conventional bypass procedure for occlusion of the minimally invasive graft, the first because of diffuse disease in the target artery and the second attributable to the technical limitations of minimally invasive coronary artery bypass grafting; both tolerated the subsequent procedure well. All patients are now angina-free. All four grafts studied by routine postoperative angiography were widely patent. Routine post-operative exercise nuclear imaging was normal in an additional patient. This procedure of minimally invasive coronary artery bypass grafting offers significant advantages compared to the conventional bypass procedure (short hospital stay, quick recovery, and, especially, avoidance of cerebrovascular accidents caused by the heart-lung machine). This minimally invasive procedure is expected to apply to a growing percentage of patients. The procedure, especially vis-à-vis angioplasty, may well offer the superior long-term patency of the mammary conduit achieved with a modest initial "investment" in hospital stay, costs of medical care, and discomfort and disability. A prospective, randomized trial comparing angioplasty and minimally invasive coronary artery bypass grafting is warranted.

Aged↗
PubMed1996

Diaphragm pacing with a quadripolar phrenic nerve electrode: an international study.

We sought to determine the international experience with the quadripolar diaphragm pacer system and to test two hypotheses: the incidence of pacer complications would be (1) increased among pediatric as compared to adult patients; and (2) highest among active pediatric patients with idiopathic congenital central hypoventilation syndrome (CCHS). Data were collected via a questionnaire coupled with the Atrotech Registry data for a total of 64 patients (35 children and 29 adults) from 14 countries. Thoracic implantation of electrodes and bilateral pacer use each occurred in 94% of all subjects. Tetraplegic (vs pediatric CCHS) patients were more typically paced 24 hours/day (P = 0.001). Pacing duration averaged 2.0 +/- 1.0 years among children and 2.2 +/- 1.1 years among adults. Infections occurred among 2.9% of surgical procedures, all in pediatric CCHS patients (vs pediatric tetraplegic patients, P = 0.01). The incidence of mechanical trauma was 3.8%, without significant differences among patient groups. The incidence of presumed electrode and receiver failure were 3.1% and 5.9%, respectively, with internal component failure greater among pediatric CCHS than pediatric tetraplegic patients (P < 0.01). Intermittent or absent function of 0-4 electrode combinations occurred among 19% of all patients, with increased frequency among pediatric CCHS than pediatric tetraplegic patients (P < 0.03). Complication-free successful pacing occurred in 60% of pediatric and 52% of adult patients. In all, 94% of the pediatric and 86% of the adult patients paced successfully after the necessary intervention. Although pacer complications were not increased among pediatric as compared to adult patients, the incidence of complications was highest among the active pediatric patients with CCHS. Longitudinal study of these patients will provide invaluable information for modification and improvement of the quadripolar system.

Adult↗
PubMed1996

Reoperative mitral valve surgery via right thoracotomy: decreased blood loss and improved hemodynamics.

BACKGROUND AND AIMS OF THE STUDY: Reoperative mitral surgery via sternotomy can be associated with significant complications, including excessive blood loss and injuries to the heart, great vessels and patent coronary artery grafts. The right antero-lateral thoracotomy offers excellent exposure with less risk from re-entry. MATERIALS AND METHODS: Between 1982 and 1992, 221 patients had repeat mitral valve procedures at our institution. Fifteen of these 221 underwent mitral valve replacement via right thoracotomy. Indications for surgery in each group included bioprosthetic valve failure, paravalvular leak and bacterial endocarditis. Fifteen patients having reoperative mitral valve surgery via right thoracotomy approach were compared with a control group of 33 patient who underwent surgery via repeat sternotomy. All thoracotomy patients underwent mitral replacement or repair with ventricular fibrillation without aortic cross-clamping. Operative time, cardiopulmonary bypass time, requirement for inotropic support, blood loss within the first six postoperative hours, number of blood units transfused, length of ICU stay, days to discharge, and 30-day survival were compared between the two groups. In addition, the preoperative PaO2/FiO2 (P/F) ratio was evaluated as a prognostic indicator. RESULTS: Bypass time (162 +/- 43 min thoracotomy group vs. 131 +/- 34 min sternotomy group), operative time (389 +/- 100 min thoracotomy group vs. 450 +/- 25 min sternotomy group), ICU stay (6 +/- 8 days thoracotomy group vs. 5 +/- 6 days sternotomy group), P/F ratio (352 +/- 142 thoracotomy group vs. 423 +/- 108 sternotomy group), and 30-day survival (93% thoracotomy group vs. 91% sternotomy group) were not found to be significantly different between groups. Of great significance was the reduction in blood loss (277 +/- 152 ml thoracotomy vs. 651 +/- 504 ml sternotomy, p < 0.05) and blood transfused (2.0 +/- 1.7 units thoracotomy vs. 6.5 +/- 3.3 units sternotomy, p < 0.01) with the thoracotomy approach. Also of significance was a reduction in frequency with which significant inotropic support was needed to separate from cardiopulmonary bypass (26% vs. 63%, p < 0.05). Despite decreased access to the heart for de-airing maneuvers, no cerebrovascular events whatsoever were noted with the thoracotomy approach. CONCLUSION: The right thoracotomy approach is recommended for redo mitral valve surgery. Despite these advantages, severe pulmonary dysfunction (as indicated by a P/F ratio less than 300) correlated with a prolonged hospital course in four thoracotomy patients; such patients should have repeat sternotomy.

Blood Loss, Surgical↗
PubMed1995

Optimal timing of coronary artery bypass graft surgery after acute myocardial infarction.

BACKGROUND: To assess optimal timing for coronary artery bypass graft surgery (CABG) after an acute myocardial infarction (AMI), all patients undergoing CABG without associated procedures at our institution from January 1, 1991, to July 30, 1992, were reviewed. Patients were divided into three groups based on time from infarct to revascularization. The control group consisted of patients operated on for angina refractory to medical management. Relative risks (incident infarction group divided by incident control group) were established for need of vasopressors, new balloon to separate from bypass, perioperative myocardial infarction, and hospital mortality. METHODS AND RESULTS: One hundred sixteen patients underwent CABG within 6 weeks of infarction. In the experimental group, 58 patients underwent CABG for non-Q-wave infarction, and 58 patients underwent CABG for Q-wave infarction. In the control group, 255 patients underwent surgery for angina without infarction. Patients were analyzed by group relative to the time between infarction and CABG. Patients were analyzed between infarction and CABG and assigned to one of three groups. Group 1 patients were revascularized within 48 hours; group 2, between 3 and 5 days; and group 3, after 5 days. Significance was determined by Fisher's exact or Mantel-Haenszel chi 2 test where appropriate. Multivariate analysis was performed on statistics that were significant. All patients within all groups after Q-wave or non-Q-wave myocardial infarction had a significantly higher risk of needing an intra-aortic balloon pump and vasopressors to be weaned from bypass and a greater incidence of perioperative MI compared with control patients. Surgical mortality is highest immediately after Q-wave infarctions. CONCLUSIONS: Patients with non-Q-wave infarction may undergo CABG relatively safely at any time. Acceptable timing for CABG after Q-wave infarction is after 48 hours.

Aged↗
PubMed1995

Simplified method of reinforced sternal closure.

A simplified method of reinforcement for closure of the precarious sternum is described. This method uses a longitudinal sternal wire on each side, which lies within the transverse wires when they are approximated. The longitudinal wires serve as impenetrable reinforcements for the sternal halves, resulting in tight, secure approximation and preventing the transverse wires from tearing through the bone. The technique has been found quick and extremely effective.

Bone Wires↗
PubMed1995

Dynamic cardiomyoplasty.

Dynamic cardiomyoplasty is a promising new technique that appears to effect symptomatic improvement in patients with NYHA class III heart failure. Objective improvement in systolic performance of the left ventricle appears small but remains to be further defined. No survival advantage has yet been realized, although this may be seen as the technique is further refined and operative risk curtailed. Mechanism of action may include a girdling effect that prevents progressive left ventricular dilatation. This effect may be independent of any role in augmenting systolic performance. Randomized clinical trials currently in progress will provide definitive answers within the next few years to these important questions.

Adult↗
PubMed1995

Skeletal muscle for cardiac assist.

Although current efforts at cardiomyoplasty have not produced the anticipated clear-cut benefits in cardiac function, replicable improvements in subjective function have resulted. Efforts at optimizing conditioning protocols, skeletal muscle strength, and timing of skeletal muscle assist devices should provide further improvements in cardiomyoplasty. Further work with alternative ways of configuring skeletal muscle for cardiac assist is extremely promising. SMVs, in particular, offer potential to augment cardiac function directly or indirectly powering pumps. Work in all these areas is in early stages, but the future is bright.

Animals↗
PubMed1995

CABG in advanced left ventricular dysfunction.

Concurrent, independent clinical series at Yale University and the University of Virginia demonstrate an important role for CABG in patients with advanced ischemic cardiomyopathy. It is found that CABG can be performed safely in these patients, both angina and congestive heart failure states improve, ejection fraction increases substantially, and good long-term longevity is achieved. Despite prior concerns, the internal mammary conduit can be used safely in these patients. It appears that CABG serves to protect viable noninfarcted muscle and to recruit hibernating ischemic muscle. CABG is suggested as an alternative to heart transplantation in this patient group.

Aged↗
PubMed1995

Left ventricular aneurysmectomy in advanced left ventricular dysfunction.

Despite widespread application in clinical practice and extensive laboratory investigations, many basic issues regarding left ventricular aneurysmectomy remain to be resolved. Analysis of clinical data from the authors' three centers and application of powerful modern imaging techniques provide important information to resolve these issues.

Aged↗
PubMed1995

Valve replacement for regurgitant lesions of the aortic or mitral valve in advanced left ventricular dysfunction.

Patients with aortic regurgitation and severe left ventricular dysfunction remain candidates for aortic valve replacement, as long as the risks of late left ventricular dysfunction and congestive heart failure have been fully discussed with the patient, the patient's family, and the referring physician. In contrast, patients with mitral regurgitation and severe systolic dysfunction are at considerable risk of more severe left ventricular dysfunction after operation, especially if mitral valve repair or chordal-sparing procedure cannot be performed. In patients who are candidates for such procedures that preserve the integrity of the subvalvular mitral apparatus, operation may be successful in selected patients despite moderate-to-severe depression of systolic function. Prognosis is guarded to poor in patients with regurgitant valvular lesions and advanced left ventricular dysfunction, and the emerging alternative treatments discussed in other articles in this Cardiology Clinics deserve consideration in these patients.

Aortic Valve↗
PubMed1995

Ventricular arrhythmias in heart failure.

The management of ventricular arrhythmias in patients with heart failure continues to pose many challenges. Three principles of therapy can be identified: (1) Empiric therapy is not warranted for asymptomatic ventricular arrhythmias. (2) Therapy for asymptomatic ventricular arrhythmias must be individualized. Appropriate management of the underlying cardiac disease is critical, and careful identification of therapeutic goals is necessary. (3) Patients at high risk should be included in prospective, controlled clinical trials whenever possible.

Anti-Arrhythmia Agents↗
PubMed1994

Latency of skeletal muscle contraction after pulse train stimulation: an important factor in correct timing of skeletal muscle cardiac assist devices.

Various configurations of conditioned skeletal muscle are under investigation for cardiac assistance in patients with end-stage cardiac failure. Optimal timing of conditioned skeletal muscle contraction is essential for effective cardiac augmentation. However, unlike mechanical methods of assistance, skeletal muscle requires time to develop peak tension. We measured "time to 50% peak tension" and "time to 90% peak tension" using an electrical strain gauge in 12 canine latissimus dorsi muscles (6 untrained controls and 6 trained with 3 months of electrical stimulation at 25 Hz with a 15% duty cycle). The "time to 50% relaxation" and the "time to 90% relaxation" after discontinuation of the stimulus were also measured. Conditioned skeletal muscle required significantly more time to develop peak tension than unconditioned skeletal muscle. Relaxation was also significantly prolonged in conditioned muscle. Notably, conditioned lattisimus needed, on average, 0.35 sec to develop peak tension and 0.20 sec for 90% relaxation. Thus, 0.55 sec of each muscle contraction/relaxation cycle was devoted to development of peak tension and subsequent relaxation. At normal canine heart rates of approximately 120 beats per minute (0.50 sec per cardiac cycle), conditioned skeletal muscle may take up to 70% of each cardiac cycle (0.35 sec) to develop 90% of peak tension. The recognition of this phenomenon in conditioned skeletal muscle is important for effective contraction timing of both human and animal skeletal muscle assist devices. Development of proper conditioning regimens for such devices may benefit from identification of those training parameters which produce a minimal "time to peak tension."

Animals↗
PubMed1994

The aortic bodice: a life-saving maneuver.

A technique is described for control of bleeding from the site of aortic cannulation after removal of the cannula. The technique employs a Dacron graft wrapped under some tension around the site.

Aorta↗