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Biomedical subjects

J J Gallagher

Publications and source records attributed to J J Gallagher.

At least 145 records · Page 8Linked to original sources
PubMed1980

Catecholamine induced double tachycardia: case report in a child.

A six-year-old girl with syncope in association with atrial flutter-fibrillation and ventricular tachycardia produced by exercise or emotion is presented. The tachycardias could be reproduced by low-dose isoproterenol infusion and were blocked by high dose propranolol therapy. Catecholamine-induced tachyarrhythmias should be suspected in children with unexplained syncope in association with exercise or emotion.

Atrial Fibrillation↗
PubMed1980

Use of the esophageal lead in the diagnosis of mechanisms of reciprocating supraventricular tachycardia.

Recent studies have emphasized the role of concealed accessory pathways in reciprocating supraventricular tachycardia. Diagnosis has generally required multicatheter electrophysiologic study. We recorded esophageal electrograms during study in 16 patients with reciprocating tachycardia due to reentry using an accessory atrioventricular pathway, and in 12 patients with reciprocating tachycardia due to reentry in the AV node. The interval from onset of ventricular depolarization to earliest atrial activation (V-AMIN), earliest atrial activity on the esophageal lead (V-AESO), and high right atrium (V-HRA) was measured. No patient with RT due to an accessory atrioventricular pathway had a V-AMIN or V-AESO less than 70 ms, or a V-HRA less than 95 ms. In contrast, 11 of 12 patients with reentry in the AV node had V-AESO intervals less than 70 ms. Esophageal recording during reciprocating tachycardia provides a simple screening procedure available to all practicing physicians to exclude the diagnosis of accessory atrioventricular pathways in the genesis of paroxysmal supraventricular tachycardia.

Adolescent↗
PubMed1980

The sock electrode array: a tool for determining global epicardial activation during unstable arrhythmias.

The conventional technique for mapping the sequence of epicardial activation uses a hand-held electrode moved over the heart to record from a number of epicardial sites one at a time, and requires 5-15 minutes to record from 50 or more sites distributed over the entire ventricular epicardium. This method is inadequate for arrhythmias that are transient or vary from beat to beat. To overcome these limitations the "sock electrode array," a contour-fitting sock containing 26 or 52 electrodes, has been developed. The nylon mesh sock is pulled over the heart and permits simultaneous recording of potentials from electrodes distributed over the entire ventricular epicardium. The electrograms are recorded and converted to digital form for computer generation of isochronous maps. Most of the epicardial activation sequence derived from the sock electrode were compared to those obtained by the hand-held electrode in six normal dogs during sinus rhythm and ventricular pacing. The sequence of local activation times acquired by both methods showed similar areas of early and late activation and comparable isochronous maps. The hand-held electrode technique required 10-15 minutes for data acquisition and another 15-30 minutes for analysis. The sock electrode array allowed electrograms from 26 epicardial electrodes to be recorded simultaneously during one cardiac cycle and computer generated isochronous maps could be displayed within 10 minutes. This method allows rapid recording and analysis of epicardial electrical phenomena and should meet the time constraints imposed during the intraoperative study of ventricular tachyarrhythmias in patients.

Animals↗
PubMed1980

'Dual atrioventricular nodal pathways" in patients with Wolff-Parkinson-White syndrome.

'Dual atrioventricular nodal pathways" were found in five patients who also had the Wolff-Parkinson-White syndrome. All five patients had a re-entrant tachycardia that used the atrioventricular node for conduction in the anterograde direction and an accessory atrioventricular pathway for conduction in the retrograde direction. One of the patients also had a re-entrant tachycardia that originated within the atrium or the atrioventricular node. Dual atrioventricular nodal pathways were identified in three of the five patients during their first electrophysiological study because the effective refractory period of the accessory atrioventricular pathway in the anterograde direction was longer than the effective refractory period of the fast atrioventricular nodal pathway. In the other two patients the dual atrioventricular nodal pathways were found only after operative division of an accessory atrioventricular pathway. Re-entrant tachycardia that uses an accessory pathway may be cured by operative division of the accessory pathway. Tachycardia resulting from re-entry within the atrioventricular node cannot be cured by an operation unless the normal conduction system is divided and a permanent pacemaker implanted. These five patients indicate the importance of determining the aetiology of tachycardia by studying the tachycardia itself and not only the type of atrioventricular conduction present.

Atrioventricular Node↗
PubMed1980

Cryosurgical ablation of the atrioventricular node-His bundle: long-term follow-up and properties of the junctional pacemaker.

We used a cryosurgical technique to ablate the atrioventricular (AV) node-His bundle in twenty-two selected patients with disabling supraventricular tachyarrhythmias unresponsive to medical management. Successful AV block was achieved in seventeen. There was no intraoperative mortality and significant surgical complications were not encountered. Electrophysiologic studies performed 7-10 days after surgery revealed that the subsidiary pacemaker had a narrow QRS complex morphology and a mean cycle length of 1244 msec. Isoproterenol (1-4 microgram/min i.v.) significantly increased (p less than 0.01) the rate of the subsidiary pacemaker (mean maximum response 1008.3 msec); atropine (2 mg i.v.) had no effect on its rate. The cycle length of the subsidiary pacemaker during long-term follow-up (mean 14.8 months) showed a small but significant (p = 0.024) increase (mean cycle length 1430 msec). Treadmill exercise in seven patients did not result in the subsidiary pacemaker exceeding the rate of the implanted demand pacemaker set at 70 beats/min. The properties of the subsidiary pacemaker suggest an intra-Hisian site of impulse formation.

Adult↗
PubMed1980

Origin of the atrial electrogram recorded from the esophagus.

The purpose of this study was to ascertain the origin of the atrial electrogram recorded on the esophageal lead. The atria and esophagus were mapped during reciprocating tachycardia in 11 patients with the Wolff-Parkinson-White syndrome and one patient with atrioventricular nodal reentry, and during right ventricular pacing in four additional patients. The esophagus was mapped by recording atrial electrograms at 1-cm intervals throughout the esophagus beginning at the most distal area where atrial depolarization was seen. The retrograde atrial activation time recorded on the esophageal lead in its distal position occurred at the same time as atrial septal depolarization in all patients. In 14 of 16 patients, the distal esophageal ventriculoatrial (VA) conduction time was also the shortest esophageal VA conduction time recorded. In two of five patients with left lateral accessory pathways, the shortest esophageal VA conduction time was noted during pullback of the lead from the esophagus instead of at the most distal area. The most likely explanation for this was an unusual anatomic relationship between the esophagus and left atrium in these two patients. We conclude that 1) the most distal esophageal atrial electrogram probably records posterior paraseptal atrial depolarization; 2) it is unusual to record clearly identifiable left atrial activation in the esophagus; and 3) the esophageal lead is not useful in locating left-sided accessory pathways.

Atrioventricular Node↗
PubMed1980

Anatomic substrate of impaired antegrade conduction over an accessory atrioventricular pathway in the Wolff-Parkinson-White syndrome.

We present a patient with Wolff-Parkinson-White syndrome who died of a myocardial infarction 19 months after clinical electrophysiologic studies. These studies suggested the presence of a left atrioventricular accessory pathway that sustained conduction well in the retrograde direction but only intermittently in the antegrade direction. Postmortem examination of the heart revealed three accessory atrioventricular pathways in proximity to each other in the posterolateral atrioventricular region. One pathway showed complete fibrosis and two showed patchy fibrosis. The fibrosis suggests an anatomic basis for the impaired antegrade conduction observed in life.

Atrioventricular Node↗
PubMed1980

Corrected transposition with severe intracardiac deformities with Wolff-Parkinson-White syndrome in a child. Electrophysiologic investigation and surgical correction.

This is a report of a 10-year-old child who underwent surgery for complex congenital heart disease consisting of corrected transposition of the great vessels, ventricular septal defect, patent ductus arterisus, severe left-sided atrioventricular (AV) valve insuffieicney (Ebstein's deformity) and Wolff-Parkinson-White syndrome. The site of his accessory AV connection was localized preoperatively at a left anterolateral site by isopotential body surface maps and by intracardiac electrophysiologic studies. He successfully underwent surgery for closure of the ventricular septal defect, ligation of the patent ductus arteriosus, replacement of the left-sided AV valve, and interruption of the accessory AV pathway. Unavoidable complete AV block acquired at surgery required subsequent permanent pacemaker therapy.

Cardiac Catheterization↗
PubMed1980

The "compensatory pause" of atrial fibrillation.

A long pause after an abnormal heat during atrial fibrillation has been called a "compensatory pause" and has been used to identify premature ventricular complexes (PVCs) and to differentiate them from supraventricular beats with aberration. The diagnostic value of the compensatory pause is controversial and has not been tested systematically with programmed stimulation and intracardiac recordings. In this study we used these methods to determine if PVCs induced during atrial fibrillation were followed by compensatory pauses. Five patients were studied who had ECGs with a normal PR interval and a normal QRS duration and morphology during sinus rhythm. Atrial fibrillation was induced by rapid atrial pacing. PVCs were induced by coupling a ventricular extrastimulus to every eighth or tenth QRS complex during atrial fibrillation. The coupling interval of the PVC was changed in 10- or 20-msec increments until the entire cardiac cycle was scanned. The mean duration of recorded atrial fibrillation was 15.7 minutes. Fifty-seven to 163 PVCs were induced in each patient. The mean cycle after the induced PVC was calculated and compared with the mean control cycle. The mean cycle after the PVC was 107-136 msec longer than the mean control cycle (p < 0.001 in every patient). This study confirms the presence of a compensatory pause after stimulated PVCs in atrial fibrillation.

Adult↗
PubMed1980

Accessory atrioventricular pathways that conduct only in the antegrade direction.

Patients with accessory atrioventricular pathways that conduct only in the antegrade direction represent an unusual variant of the Wolff-Parkinson-White syndrome. This report describes such patients and compares them with patients with accessory pathways that demonstrate bidirectional conduction. Of 143 patients with single accessory pathways, seven demonstrated exclusive antegrade conduction (study group), 111 demonstrated bidirectional conduction (control group), and 25 demonstrated exclusive retrograde conduction. Study group patients were significantly older than patients in the control group (42 +/- 9.8 years and 31.4 +/- 13.9 years, respectively, p < 0.0001). Refractoriness and conduction characteristics of the accessory pathways in the antegrade direction in the study group were not different from those in the control group. Control group patients presented with atrioventricular reentrant tachycardia (58 of 111), atrial fibrillation (23 of 111), both of these arrhythmias (19 of 111), or no documented arrhythmia (11 of 111). Study group patients presented with only atrial fibrillation (six of seven). An accessory pathway with only antegrade conduction is a rare cause of symptoms in the Wolff-Parkinson-White syndrome. These patients are asymptomatic until atrial fibrillation develops as the patient ages. Despite the absence of retrograde conduction over the accessory pathway, its antegrade functional properties are similar to pathways that demonstrate bidirectional conduction.

Adolescent↗
PubMed1980

Electrophysiologic evaluation and surgical correction of Wolff-Parkinson-White syndrome in children.

The Wolff-Parkinson-White syndrome is due to a congenital heart malformation that is the result of one or more persistent anomalous atrioventricular pathway(s). While supraventricular tachycardia is the most commonly associated arrhythmia, there is a wide spectrum of associated arrhythmias including fatal ventricular fibrillation. It is now known that surgical ablation of the anomalous pathway(s) can result in complete cure of arrhythmias in some patients. The purpose of this report is to describe the current methods used for the preoperative and operative electrophysiologic evaluation and surgical treatment in children with the Wolff-Parkinson-White syndrome, as illustrated by the case presentation of a normal eight-year-old patient who had ventricular fibrillation.

Cardiac Pacing, Artificial↗
PubMed1980

"Les torsades de pointes": an unusual ventricular arrhythmia.

Since the original description by Dessertenne, predominantly European literature has reported the features of the unusual ventricular arrhythmia "les torsades de pointes." Named because of the way the polarity of the QRS complexes seems to spiral around the baseline of the ECG, this arrhythmia is virtually always associated with prolongation of the Q-T interval. Its importance lies not in its unusual structure but in the potentially fatal outcome if conventional treatment is administered. Antiarrhythmic drugs that further prolong the Q-T interval frequently aggravate the arrhythmia and are contraindicated. Overdrive pacing, preferably atrial, is the treatment of choice with attention to any correctable causes of associated Q-T prolongation. Electrophysiologic studies so far favor a re-entrant cause for the arrhythmia, but the exact mechanism and its true relation to both conventional ventricular tachycardia and ventricular fibrillation remain to be defined.

Adult↗
PubMed1980

The surgical approach to the septal area of the heart based on experiences with 45 patients with Kent bundles.

Experience gained from interruption of 45 anterior and posterior septal Kent bundles has permitted the formulation of a safe surgical approach to the anterior and posterior divisions of the septal area. To clarify the surgical anatomy of this difficult region, the posterior space has been likened to a trihedral pyramid, toppled on its side, with the apex the right fibrous trigone, the right and left atria making two of its sides, and the muscular ventricular septum and the left ventricle or third side, the floor. The pyramidal space contains fat, the atrioventricular (AV) nodal artery, and coronary sinus. The anterior division extends from the right fibrous trigone anteriorly to the free wall. The right atrium is connected to the anulus fibrosus, which rests upon the muscular septum and infundibulum. The AV node and His bundle are protected from dissections in both divisions by the atrial septum and right fibrous trigone. The cases of 31 patients with posterior septal Kent bundles in whom interruption was attempted resulted in division in 20, forced His division in four, and failure in seven. Elective His interruption was done in three. Success occurred in the last 10. Three failures at interruption occurred in 14 anterior septal Kent bundles.

Arrhythmias, Cardiac↗
PubMed1980

Attentiveness and responsiveness to auditory stimuli of children at risk for mental retardation.

The major hypothesis in the present study was that differences between high-risk and low-risk children in performance on standardized tests of cognitive ability would be explained, in part, by differences in attentiveness to auditory stimuli and differences in task orientation. The data collected revealed the anticipated higher standardized test scores for low-risk children. Within the high-risk sample, few differences were found between children who attended an intervention day-care program and those who did not. Measures from a laboratory task and a free-play observation suggested that attention is a key factor in understanding the high-risk child's development and also that differences in attention between high- and low-risk children can be reliably obtained as early as 3 years of age. A lessened attention span was demonstrated by high-risk children to both auditory and visual stimuli if either were complex or demanding.

Attention↗
PubMed1979

Ventricular fibrillation in the Wolff-Parkinson-White syndrome.

To examine the risk of ventricular fibrillation in patients with the Wolff-Parkinson-White syndrome, we compared patients who had this syndrome and a history of ventricular fibrillation related to preexcitation with patients who had the syndrome without this history. Ventricular fibrillation occurred during atrial fibrillation, with rapid conduction over the accessory pathway, and these patients had a higher prevalence of both reciprocating tachycardia and atrial fibrillation (14 of 25 vs. 18 of 73, P = 0.004) and multiple accessory pathways (five of 25 vs. four of 73, P = 0.012). The shortest preexcitation R-R interval during atrial fibrillation was less in the group with ventricular fibrillation (mean shortest R-R, 180 vs. 240 milliseconds, P less than 0.0001) as was the average R-R interval (mean average R-R, 269 vs 340 milliseconds, P less than 0.0001). Patients with Wolff-Parkinson-White syndrome who are most susceptible to ventricular fibrillation have a history of atrial fibrillation and reciprocating tachycardia, demonstrate rapid conduction over an accessory pathway during atrial fibrillation and have multiple accessory pathways.

Adolescent↗
PubMed1979

Giant diverticular of the sigmoid colon: a review of differential diagnosis and operative management.

Giant sigmoid diverticula ("giant gas cysts," "giant sigmoid cysts") are an unusual complication of diverticulitis. We have recently seen two patients with such lesions, bringing the total number of reported cases to 48. Most patients are elderly and complain of abdominal pain or the presence of an abdominal mass. Air trapping by a ball-valve mechanism may be responsible for formation of the fibrous cysts. The gas-filled structures can usually be differentiated from other conditions by contrast studies. Excision of the cyst and adjacent colon with anastomosis can usually be accomplished safely under elective circumstances.

Adult↗
PubMed1979

Transfer of coupling of premature ventricular contractions to an ectopic ventricular tachycardia: a mechanism for atypical bidirectional tachycardia.

Bidirectional tachycardia was observed on Holter tracings recorded from a dog three days after the production of a small freeze lesion on the wall of the left ventricle. A bigeminal rhythm with fixed coupling of ventricular premature contractions was interrupted by a burst of ventricular tachycardia of different morphology. The ventricular premature contractions, originally coupled to the sinus beats, became coupled to the new ventricular tachycardia with an identical coupling interval. This resulted in a dibirectional tachycardia, created by the "transfer" of coupling of premature ventricular contractions to a separate ectopic ventricular tachycardia.

Animals↗