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S S Barold

Publications and source records attributed to S S Barold.

At least 73 records · Page 4Linked to original sources
PubMed1998

Optimal cardiac pacing in patients with coronary artery disease.

Pacemaker patients with coronary artery disease and angina pectoris fare better with devices providing AV synchrony and rate increase on exercise provided the programmed upper rate is not excessive. Optimal programming requires knowledge of the factors influencing pacemaker rate response, MVO2 and cardiac sympathetic activity. Inappropriately high rates during rate adaptive pacing can be controlled by new multisensor systems with sensor cross-checking to avoid false positive responses with inappropriate increases in the pacing rate. Permanent pacing in patients with intractable angina who are unsuitable for interventional procedures permits more aggressive pharmacological therapy.

Angina Pectoris↗
PubMed1998

Prevention of atrial arrhythmias during DDD pacing by atrial overdrive.

We evaluated the effect of atrial overdrive on the incidence of atrial arrhythmias (AA) in 22 patients (67 +/- 9 years, 7 women, 15 men) with Chorus 6234 DDD pacemakers. Atrial overdrive was defined as a programmed paced rate 10 ppm faster than the mean ventricular rate stored for the last 24-hour period in the pacemaker memory. The protocol consisted of three phases of 1 month each. Phase I: observation after discontinuation of antiarrhythmic therapy. Phase II: arrhythmia analysis using the pacemaker memory after programming the lower rate to 55 ppm. The fallback function and histogram data were used to document the number and maximal duration of AA episodes as well as the total AA time in a month. Phase III: atrial overdrive. The mean ventricular heart rate was 65 +/- 4 beats/min before atrial overdrive versus 75 +/- 5 with atrial overdrive (P = 0.02). At the end of phase II, all patients presented with AA episodes (mean number per patient: 42 +/- 78 in one month). In phase III (with atrial overdrive), 14 (64.6%) patients had no recorded AA (group A). In the other eight patients with persistent AA episodes in phase III (group B), there was a significant reduction in the number of AA episodes (90 +/- 106 in phase II vs 38 +/- 87 in phase III; P = 0.01), their total duration (166 +/- 115 in phase II vs 92 +/- 134 hours in phase III; P = 0.03) and their maximal duration (121 +/- 103 in phase II vs 85 +/- 89 min; P = 0.04). Our short-term data suggest that atrial overdrive prevents or reduces AA episodes and demonstrate the feasibility and need of long-term studies to determine whether this benefit is sustained.

Aged↗
PubMed1998

Advanced atrioventricular block in a 39-year-old man with acute rheumatic fever.

This report describes the development of advanced (2:1 and 3:1) AV block in a 39-year-old man with acute rheumatic fever. AV block progressed from first-degree to type I second-degree and finally to advanced AV block. The latter lasted 5 days. AV block regressed in a stepwise fashion via sustained type I second-degree AV block and eventually first-degree AV block. The PR interval returned to normal several weeks after resolution of second-degree AV block. In view of the resurgence of acute rheumatic fever, the diagnosis of acute rheumatic fever should now be considered in young adults or middle-aged patients presenting with second-degree or third-degree AV block of undetermined etiology.

Acute Disease↗
PubMed1997

The pacemaker syndrome -- a matter of definition.

Pacemaker syndrome is an iatrogenic disease that is often underdiagnosed. We propose that pacemaker syndrome represents the clinical consequences of suboptimal atrioventricular (AV) synchrony or AV dyssynchrony, regardless of the pacing mode. Clinicians implanting and programming pacemakers should attempt to optimize AV synchrony to prevent the occurrence of pacemaker syndrome.

Cardiac Output, Low↗
PubMed1997

Contemporary issues in rate-adaptive pacing.

This review addresses a number of questions pertaining to contemporary rate-adaptive pacemakers that include the role of dual sensor systems, sensor blending and cross-checking, automaticity, nonrate-related sensor functions, prevention of arrhythmias, and several other areas of clinical importance.

Algorithms↗
PubMed1997

Pacemaker induced repetitive nonreentrant ventriculoatrial synchrony: initiation and termination by ventricular extrasystole.

During dual chamber pacing, repetitive ventriculoatrial (VA) synchrony secondary to retrograde conduction can occur whenever otherwise effectual atrial stimuli fall continually within the atrial myocardial refractory period generated by preceding unsensed retrograde atrial depolarization. The latter falls within the pacemaker atrial refractory period and cannot initiate endless loop tachycardia, another form of repetitive VA synchrony secondary to a reentrant process through the pacemaker and the heart. This report describes the usefulness of Holter recordings in the diagnosis of repetitive nonreentrant VA synchrony and documents initiation and termination of this process by a ventricular extrasystole.

Aged↗
PubMed1997

Analysis of electrophysiological activity in Koch's triangle relevant to ablation of the slow AV nodal pathway.

Atrioventricular junctional reentrant tachycardia (AVJRT) is the most common form of paroxysmal regular supraventricular tachycardia. In patients with disabling, drug refractory AVJRT, catheter ablation has evolved rapidly from a last-resort treatment in the form of interruption of atrioventricular (AV) conduction to selective modification of AV nodal function as an ideal treatment. This article will focus on the frequently unappreciated electrophysiological activities recordable in man in Koch's triangle during ablation of the so-called slow pathway.

Atrioventricular Node↗
PubMed1997

Failure of automatic mode switching: recognition and management.

Dual chamber pacing is desirable to optimize AV synchrony and to potentially decrease the incidence of supraventricular tachyarrhythmias. Patients with alternating periods of both supraventricular tachyarrhythmias and bradycardia pose a difficult challenge when standard dual chamber pacemakers are implanted. The automatic mode switching mode algorithm was introduced to prevent tracking of paroxysmal supraventricular tachyarrhythmias and avoid the adverse hemodynamic and symptomatic consequences of a rapid ventricular response. In some cases, failure to mode switch may take place when the atrial signal during tachycardia is of insufficient amplitude to be sensed. Failure to mode switch may also occur when the atrial signal periodically occurs in the atrial blanking period(s). In this article, we describe failure to mode switch in seven patients with paroxysmal supraventricular tachyarrhythmias after a Telectronics Meta DDDR 1254 device was implanted. Each patient had paroxysmal atrial flutter and/or atrial fibrillation and presented with either repetitive episodes of oscillation between atrial tracking and mode switching to a nonatrial tracking pacing mode or complete failure to mode switch. Six of seven patients were taking antiarrhythmic drugs that resulted in slowing of the atrial cycle length. Pacemaker reprogramming was required in each case to restore reliable mode switching during subsequent recurrences of the atrial tachyarrhythmias. We conclude that careful pacemaker programming of patients with paroxysmal atrial flutter and the Telectronics Meta DDDR 1254 is necessary when patients are taking an antiarrhythmic drug that slows atrial cycle length.

Aged↗
PubMed1996

Cardiac pacing.

Explore the source record for details and available documents.

Heart Block↗
PubMed1996

Treatment of refractory ventricular fibrillation by combined internal (epicardial) and external (transthoracic) defibrillation.

This report describes a modified defibrillation technique used successfully in a patient with an implanted epicardial cardioverter defibrillator who developed refractory ventricular fibrillation. During operative testing at the time of generator replacement, two episodes of intractable ventricular fibrillation were terminated by using a combined internal (epicardial)-external (transthoracic) defibrillation system that delivered a 360-J shock between the anterior epicardial patch and a large posterior skin electrode.

Defibrillators, Implantable↗