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M Eldar

Publications and source records attributed to M Eldar.

At least 73 records · Page 4Linked to original sources
PubMed1994

A closed-chest pig model of sustained ventricular tachycardia.

The goal of this study was to develop and explore a closed-chest animal model of sustained VT. Seven of 11 domestic pigs had successful induction of myocardial infarction by injection of agarose gel microbeads into the left anterior descending coronary artery through an inflated balloon angioplasty catheter. Four of the first five pigs died and seem to represent a "learning experience." During a 3- to 50-day follow-up period, each pig underwent 1-3 electrophysiological studies. Sustained, monomorphic VT was induced 1-4 times in 5 of the 7 pigs (a total of 19 episodes), was reproducible during the same study in all pigs, and could be repetitively induced during successive studies in some. Ventricular fibrillation was induced less frequently (nine episodes) and was successfully terminated by DC shock in eight episodes. We conclude that a closed-chest pig model of VT is feasible and is associated with a relatively high induction rate of sustained, monomorphic, and reproducible VT and a relatively low mortality rate.

Animals↗
PubMed1993

[Radiofrequency ablation of idiopathic ventricular tachycardia].

Ablation by radiofrequency has recently come into use to treat cardiac arrhythmias, mostly supraventricular tachycardia. We describe 2 males aged 14 and 24, respectively, with idiopathic ventricular tachycardia. They underwent endocardial mapping and the exit points of the tachycardia were identified. In 1 of them tachycardia originated in the left ventricle, and the other in the outflow tract of the right ventricle. Radiofrequency ablation of the arrhythmia was successful in both.

Adolescent↗
PubMed1993

[Tachycardia].

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Electrocardiography↗
PubMed1993

Intracoronary injection of basic fibroblast growth factor enhances angiogenesis in infarcted swine myocardium.

OBJECTIVES: This study was performed to examine the effect of intracoronary exogenous basic fibroblast growth factor (bFGF) on angiogenesis in infarcted myocardial regions. BACKGROUND: Exogenous bFGF is a potent promoter of angiogenesis. Little information is available on its effect on myocardial angiogenesis. METHODS: Myocardial infarction was induced in 10 pigs by intracoronary injection of microscopic beads. Four pigs served as a control group; in six pigs slow-release bFGF was delivered by the beads. Cardiac performance was evaluated by repeated echocardiographic measurement and angiogenesis was evaluated by immunohistochemical studies 14 days later. RESULTS: As compared with control pigs, pigs treated with bFGF had higher microvessel counts (mean +/- SEM) in both viable tissue (141 +/- 27 per field vs. 39 +/- 4, p = 0.01) and nonviable tissue (329 +/- 26 per field vs. 95 +/- 7, p < 0.001) within the infarct area. No significant differences in total regional left ventricular wall motion were noted between the two groups throughout the 14-day study period. CONCLUSIONS: In the swine, direct intracoronary application of bFGF to infarcted myocardium enhances myocardial neovascularization within 2 weeks.

Animals↗
PubMed1993

Evaluation of a new mechanical atherectomy system (TRAC) in normal canine coronary arteries. Transluminal Rotary Atherectomy System.

BACKGROUND: The feasibility and safety of a new mechanical atherectomy device, the Transluminal Rotary Atherectomy System (TRAC), for coronary application was examined in vivo in eight dogs. The system operates over a standard balloon coronary guide wire and excises and removes the atherosclerotic material in a single application. METHODS: The TRAC was introduced percutaneously using routine cardiac catheterization technique in four open-chest dogs (acute experiments) and in four closed-chest dogs (chronic experiments). RESULTS: Coronary angiography at the end of the procedure and 1-3 days later demonstrated normal coronary arteries without evidence of dissection, perforation, spasm, or thrombus formation. Macroscopic examination revealed perivascular bleeding along the treated coronary arteries in two out of eight dogs. Microscopic examination of these arteries demonstrated minimal endothelial peeling. Histology of the other coronary arteries demonstrated normal intact blood vessels without evidence for thrombus formation. CONCLUSIONS: These results demonstrate that it is feasible and relatively safe to introduce and operate the new TRAC mechanical atherectomy system in the normal coronary arteries of a beating dog heart.

Animals↗
PubMed1993

The Bard Rotary Atherectomy System (BRAS): initial experience in patients with peripheral vascular disease.

Sixteen patients with a mean age of 65.4 +/- 9.8 years and suffering from peripheral vascular disease underwent peripheral atherectomy using a new mechanical device--the BARD Rotary Atherectomy System (BRAS). The BRAS is an "over the wire" system that consists of a spiral guidewire and a handheld motor drive unit, which rotates at 1,500 rpm. Prior to the procedure angiography demonstrated the presence of 18 obstructions (1 tibial, 2 popliteal, 15 superficial femoral arteries) with a mean stenosis of 95.7 +/- 8%. Successful atherectomy was achieved in 16 of 18 lesions and resulted in an 89% immediate success rate and a significant (P less than 0.01) reduction of stenosis to 37.8 +/- 12.5%. There were no significant complications. The excised and removed material embedded over the spiral guidewire demonstrated the presence of fibrotic tissue, fatty lesions, and calcium deposits. Medial or adventitial layers were not present in the removed atherosclerotic material. Mean ABI was significantly (P less than 0.01) increased from 0.38 +/- 0.17 to 0.55 +/- 0.21 following atherectomy. Angiographic follow-up obtained in ten patients 8.8 +/- 5.2 months following the procedure demonstrated restenosis in six of those ten patients. The ABI at this time remained unchanged. These results demonstrated that the new BRAS mechanical atherectomy system is feasible and safe for recanalization of severely stenosed arteries in patients with peripheral vascular disease.

Aged↗
PubMed1992

[Tachycardia].

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Electrocardiography↗
PubMed1992

Primary ventricular tachycardia in acute myocardial infarction: clinical characteristics and mortality. The SPRINT Study Group.

OBJECTIVE: To examine the immediate and long-term clinical and prognostic significance of primary ventricular tachycardia, defined as tachycardia of ventricular origin occurring within 48 hours of acute myocardial infarction in patients without hemodynamic compromise (Killip class I). DESIGN: Prospective cohort study. SETTING: Intensive coronary care units in eight regional, referral, and university hospitals. PATIENTS: A total of 162 patients with primary ventricular tachycardia, both sustained and nonsustained (study group), and 2578 counterparts without ventricular tachycardia (reference group). MEASUREMENTS: In-hospital rates of atrial fibrillation, atrioventricular block, congestive heart failure, cardiogenic shock, and cardiac arrest. In-hospital and 1-year follow-up rates of sudden death, nonsudden cardiac death, and noncardiac death. RESULTS: The study and reference groups had similar mortality (in-hospital, 6.8% and 9.6%, P greater than 0.2 and at 1 year after discharge, 3.7% and 5.4%, P greater than 0.2, respectively) and in-hospital complication rates (atrioventricular block, 13.0% and 9.7%, P greater than 0.2; cardiogenic shock, 3.7% and 3.0%, P greater than 0.2; cardiac arrest, 1.8% and 4.4%, P greater than 0.2, respectively). Patients with sustained ventricular tachycardia (28 patients) compared with those with nonsustained ventricular tachycardia (134 patients) had higher rates of polymorphic tachycardia (50% compared with 6%, P = 0.001), in-hospital total cardiac mortality (21% compared with 4%, P = 0.003) and sudden-death mortality (14% compared with 2%, P = 0.001); they also showed a trend toward a higher in-hospital mortality than the reference group (21.4% compared with 9.6%, P = 0.15) but had no increased mortality 1 year after discharge (4.6% compared with 5.4%, P greater than 0.2). CONCLUSIONS: As a group, patients with primary ventricular tachycardia do not differ from counterparts without primary ventricular tachycardia in their in-hospital clinical course and 1-year prognosis. Primary sustained ventricular tachycardia is often polymorphic and carries worse in-hospital prognosis than nonsustained tachycardia. However, it does not predict recurrent ventricular tachycardia or increased sudden-death rates during the next year.

Coronary Care Units↗
PubMed1992

[Tachycardia].

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Electrocardiography↗
PubMed1992

Combined use of beta-adrenergic blocking agents and long-term cardiac pacing for patients with the long QT syndrome.

OBJECTIVE: The objective of this study was to review our current experience using a combination of beta-adrenergic blocking agents and long-term cardiac pacing to treat patients with the idiopathic long QT syndrome. BACKGROUND: Patients with the idiopathic long QT syndrome are at high risk for sudden cardiac death. Before combination therapy, 20 of the 21 study patients experienced either cardiac arrest (n = 8) or syncope (n = 18) and 11 had documented polymorphous ventricular tachycardia. Nine of these patients had not responded to isolated beta-blocker therapy and five had not responded to isolated left cervicothoracic sympathectomy. METHOD: All patients were treated with combined beta-blocker therapy and long-term cardiac pacing at a rate designed to normalize the QT interval. RESULTS: Cardiac pacing at rates of 70 to 125 beats/min resulted in shortening of the QT and corrected QT (QTc) intervals from 517 +/- 78 and 541 +/- 62 ms to 404 +/- 37 and 479 +/- 41 ms, respectively. The mean follow-up interval after institution of pacing was 55 +/- 45 months. The only sudden death occurred in a patient who had discontinued beta-blocker therapy. Syncope occurred in four patients, two of whom had interrupted pacemaker function due to lead fracture. Pacemaker problems, partly attributable to the specific rate required for QT interval shortening and to avoidance of T wave sensing, were relatively common. No patient who continued the combination therapy died, but 10% of these patients had a recurrence of symptoms. CONCLUSIONS: Combination therapy with a beta-blocker and cardiac pacing appears to be a highly effective primary therapy for symptomatic patients with the long QT syndrome and to provide excellent adjunctive therapy for patients who require insertion of an automatic internal defibrillator.

Adrenergic beta-Antagonists↗