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Biomedical subjects

B Olshansky

Publications and source records attributed to B Olshansky.

At least 37 records · Page 2Linked to original sources
PubMed1999

Case 2: a patient with an intermittent racing heartbeat.

Most clinicians currently rely on patient history and specific electrocardiographic criteria to establish the diagnosis of arrhythmias. However, as illustrated by this case, the physical examination-especially auscultation of the first heart sound-can also provide useful diagnostic clues.

Adolescent↗
PubMed1999

A practical approach to atrial fibrillation.

Management of atrial fibrillation is still an individualized proposition, requiring considerable clinical judgment to select the most effective means of controlling cardiac rate and rhythm and preventing thromboembolism and stroke. The advantages and disadvantages of electric shock cardioversion, catheter ablation, and several medicinal and mechanical agents are discussed.

Adult↗
PubMed1999

Catheter ablation of accessory pathways, atrioventricular nodal reentrant tachycardia, and the atrioventricular junction: final results of a prospective, multicenter clinical trial. The Atakr Multicenter Investigators Group.

BACKGROUND: The purpose of this study was to evaluate the safety and efficacy of a temperature-controlled radiofrequency catheter ablation system. METHODS AND RESULTS: The patient population included 1050 patients who had undergone ablation of atrioventricular nodal reentrant tachycardia (AVNRT), an accessory pathway (AP), or the atrioventricular junction (AVJ). Ablation was successful in 996 patients. The probability of success was highest among patients who had undergone ablation of the AVJ, lowest in patients who had undergone ablation of an AP, and in between for patients who had undergone ablation of AVNRT. A major complication occurred in 32 patients. Four variables predicted ablation success (AVJ, AVNRT, or left free wall AP ablation and an experienced center). Four factors predicted arrhythmia recurrence (right free wall, posteroseptal, septal, and multiple APs). Two variables predicted development of a complication (structural heart disease and the presence of multiple targets), and 3 variables predicted an increased risk of death (heart disease, lower ejection fraction, and AVJ ablation). CONCLUSIONS: These findings may serve as a guide to clinicians considering therapeutic options in patients who are candidates for ablation.

Adolescent↗
PubMed1999

Atrial Flutter.

Atrial flutter can have serious short- and long-term consequences. Treatment options for an acute attack include direct-current cardioversion, atrial pacing, and intravenous drug therapy. For chronic disease or for recurrence, treatment options include ablation of the flutter, rate-controlling therapy, and antiarrhythmic drugs. Anticoagulation should be considered.

Journal Article↗
PubMed1999

Clinical significance of syncope in the electrophysiologic study versus electrocardiographic monitoring (ESVEM) trial. The ESVEM Investigators.

BACKGROUND: Syncope may portend risk of death, but which patients with syncope are at high risk remains unclear. OBJECTIVE: The ESVEM trial, a multicenter randomized prospective trial, provided the opportunity to compare mortality rates of patients enrolled with syncope to those enrolled with spontaneous ventricular arrhythmias. METHODS: Patients enrolled in the ESVEM trial presenting with syncope alone (25 patients) or in combination with ventricular tachycardia (24 patients) were compared with patients with spontaneous ventricular tachycardia alone (332 patients) or ventricular fibrillation (105 patients). All patients had ventricular tachyarrhythmias induced at electrophysiology testing of >/=10 premature ventricular complexes per hour on Holter monitor. RESULTS: Of all patients randomly assigned, arrhythmic death and total mortality rates were the same for those with syncope alone, with ventricular tachycardia and syncope, with ventricular tachycardia alone, or with ventricular fibrillation. At 1 year, arrhythmic and total mortality rate for all patients was 21% and 24%, respectively; for patients with syncope alone, 30% and 29%, respectively (P = NS). At 4 years, arrhythmic death and total mortality rate for all patients was 33% and 42%, respectively; for patients with syncope alone, 37% and 42%, respectively (P = NS). CONCLUSION: Syncope, associated with induced ventricular tachyarrhythmias at electrophysiologic testing, indicates high risk for death, similar to that of patients with documented spontaneous ventricular tachyarrhythmias.

Aged↗
PubMed1999

Cardiac arrhythmias and the athlete.

Athletes, although the healthiest segment of society, can develop cardiac arrhythmias. Benign bradycardias and atrial and ventricular premature contractions are common and seldom require treatment. Supraventricular tachycardias are less common and are usually not life-threatening, but do require treatment. Ventricular arrhythmias, although uncommon, are life-threatening and require treatment. Most athletes with ventricular arrhythmias have structural cardiac abnormalities, and further competitive play is usually prohibited. Commotio cordis, which is a recently described syndrome of sudden death caused by low-energy chest wall impact, may account for a significant percentage of the sudden deaths in athletes.

Arrhythmias, Cardiac↗
PubMed1997

Thromboembolism in chronic atrial flutter: is the risk underestimated?

OBJECTIVES: We sought to evaluate the risk of thromboembolic events in the presence of chronic atrial flutter and to determine the impact of anticoagulation therapy, if any, on this risk. BACKGROUND: Thromboembolic events are thought to be rare after cardioversion of atrial flutter. METHODS: This study was a retrospective analysis of 110 consecutive patients referred to the electrophysiology laboratory for cardioversion of chronic atrial flutter from 1986 to 1996. Atrial flutter was present for at least 6 months. Of the 110 patients reviewed, 100 had adequate information available regarding the effectiveness of anticoagulation (mean age 64 years, range 27 to 86; 75 men, 25 women; mean left ventricular ejection fraction 42%). RESULTS: Thirteen patients (13%) had a thromboembolic event. Of these, seven were attributable to causes other than atrial flutter. In the remaining six patients (6%), thromboembolic events occurred during a rhythm of atrial flutter or after cardioversion to sinus rhythm. Other causes of thromboembolism were excluded. Effective anticoagulation was associated with a decreased risk of thromboembolism (p = 0.026). CONCLUSIONS: Patients with chronic atrial flutter are at an increased risk of thromboembolic events. Effective anticoagulation may decrease this risk.

Adult↗
PubMed1997

Autonomic influences in atrial ischemia: vagally mediated atrial conduction improvement.

To investigate the effects of autonomic nerve activation on electrophysiological properties of ischemic atrial myocardium, experiments were performed in 10 open chest adult dogs anesthetized with xylazine and alpha-chloralose. Ischemia was created in the right atrial free wall by ligation of one or more branches of the right coronary artery. Bipolar electrograms were recorded from multiple sites in the ischemic and non-ischemic zones. The atria were paced at 400 ms and 180 ms to assess conduction properties. One hour after ligation, delayed activation, electrogram fractionation, and electrogram alternans were observed in the ischemic zone. All local conduction abnormalities were heart rate dependent in that they were only observed at a pacing cycle length of 180 ms. The average duration of ischemic zone electrograms was significantly prolonged from 17.7+/-1.6 ms to 26.4+/-1.6 ms (P<0.001). Right and left vagal stimulation significantly shortened the electrogram duration in the ischemic zone from 26.4+/-1.6 ms to 19.7+/-1.1 ms (P<0.01) and 20.0+/-1.1 ms (P<0.01), respectively. Ischemia-induced electrogram alternans was eliminated completely. During right and left stellate stimulation, electrogram duration was not altered and alternans was still present. In conclusion, vagal stimulation in this canine model improves local conduction in ischemic myocardium in the right atrium. This effect may be mediated by a reversal of the ischemia-induced membrane depolarization and a shortening of refractoriness in the atrium during vagal activation.

Animals↗
PubMed1997

Teletronics 330-801 atrial lead extraction via the subclavian approach.

BACKGROUND: The Telectronics 330-801 atrial J (801) lead was recalled after reports implicated lead fracture/retention wire protrusion in patient mortality and morbidity. Recent reports suggest that 801 lead extraction may be associated with substantial morbidity and, possibly, excess mortality. We hypothesized that the 801 lead could be extracted using the subclavian approach with a high success rate and acceptable morbidity. METHODS: We analyzed the clinical outcomes in 60 consecutive patients who underwent 801 lead extraction. RESULTS: Sixty patients (34 women) with a mean age of 67 +/- 14.8 years had 18 class I, 13 class II, and 29 class III fractures. The lead age was 39 +/- 17 months. The subclavian approach was successful in 58 of 60 patients (96%). Complications, three major and eight minor, occurred in 10 of 60 patients (16%). All complications were successfully treated. There were no deaths. Only concurrent ventricular lead extraction was associated with complications (p = 0.008 by Fisher's exact test). CONCLUSIONS: Telectronics 801 leads can be successfully extracted using the subclavian approach with acceptable short-term morbidity, low mortality, and excellent long-term results.

Adult↗
PubMed1997

Symptomatic atrioventricular block in an atriofascicular pathway inserting into the left bundle branch without apparent atrioventricular node function.

We report a patient with symptomatic AV block associated with conduction solely through an atriofascicular pathway that inserted into the left bundle branch. There was no apparent conduction present through the AV node. There was, however, passive activation through the His-Purkinje system. His-bundle pacing demonstrated normal conduction through both right and left bundles. This is the first report of such a case.

Atrioventricular Node↗