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Biomedical subjects

J J Gallagher

Publications and source records attributed to J J Gallagher.

At least 127 records · Page 7Linked to original sources
PubMed1982

Localization of the site of ventricular preexcitation with body surface maps in patients with Wolff-Parkinson-White syndrome.

Forty-nine patients with Wolff-Parkinson-White syndrome, ages 7 weeks to 51 years, were studied with isopotential body surface maps during normal sinus rhythm, atrial pacing or induced atrial fibrillation. The location of the accessory pathway was determined by multicather electrophysiologic study or surgical ablation of the accessory pathway. When fusion was minimized and ventricular activation primarily controlled by a single accessory pathway, the distribution of positive and negative potentials on the anterior and posterior torso during QRS (observed at 40 msec) and the ST segment were an excellent index of the location of the site of the accessory pathway. The relationship between a specific sequence of QRS-T wave body surface maps and a specific preexcitation site was similar from patient to patient in the presence of marked differences in age, size, and different cardiac status due to structural congenital cardiac defects. The localization of the site of the accessory pathway using distributions too early in QRS (before 40 msec) was unreliable because the early distributions varied from patient to patient for the same preexcitation site; however, the potential distributions during the ST segment were both stable and consistent from patient to patient for the same preexcitation site. The presence of significant fusion of ventricular activation initiated via a single accessory pathway and the normal conduction system or via multiple accessory pathways complicated the interpretation of body surface distributions. Thus, one can predict accurately at least seven preexcitation sites by the combined use of QRS and ST-segment body surface maps.

Adolescent↗
PubMed1982

Changes in ventriculoatrial intervals with bundle branch block aberration during reciprocating tachycardia in patients with accessory atrioventricular pathways.

During reciprocating tachycardia in patients with accessory atrioventricular pathways, the observation of changes in ventriculoatrial (VA) intervals with bundle branch block (BBB) aberration has been used to localize the site of the pathway and prove the participation of the pathway in the tachycardia. In this report we present the changes observed during BBB in 93 patients with single atrioventricular pathways in whom the site of their pathways was subsequently proved at the time of their surgical interruption. In patients with left or right free wall pathways, the minimum VA interval (VA min) increased by 61 +/- 19 msec with ipsilateral BBB, whereas no change occurred with contralateral BBB. The smallest increase in the VA interval was 35 msec. In 14 patients, shortening of the AH intervals resulted in changes in overall cycle length that were less than 35 msec. Patients with septal pathways all had changes in VA min of 25 msec or less with either right or left bundle branch block (RBBB or LBBB), which suggests that a clear differentiation between septal and free wall pathways can be made on the basis of changes in VA min. In patients with anteroseptal pathways, VA min intervals frequently prolonged with RBBB (16 +/- 9 msec) but not with LBBB. In patients with posteroseptal pathways, VA min frequently prolonged with LBBB (13 +/- 8 msec) but not with RBBB. Therefore, the observed changes in VA min with BBB may serve as an important indicator of the site of an accessory pathway and may provide guidance in the choice of surgical therapy.

Adolescent↗
PubMed1982

[Closed chest interruption of A-V conduction in the treatment of refractory supraventricular tachyarrhythmias. A clinical contribution].

The AA. describe a technique for interrupting the A-V conduction using a direct-current shock delivered from a cardioversion unit to the A-V junctional tissue by means of a conventional electrode-catheter. The method was used in 2 patients with refractory supraventricular tachycardias. After the procedure both patients received a programmable A-V sequential pacemaker. The first patient, with cardiomyopathy and intermittent W-P-W syndrome, had a 2-year history of iterative reciprocating tachycardia and occasional episodes of atrial flutter-fibrillation. The second patient, with coronary heart disease, had recurrent episodes of atrial flutter for at least 2 years. In patient 1 the shock caused a suprahisian first-degree block. Atrial pacing at 580 ms cycle length provoked a 2:1 block and ventricular pacing showed no retrograde conduction. The patient, who is not pacemaker-dependent, is now free from reciprocating tachycardia and, during atrial flutter-fibrillation episodes, the ventricular rate varies from 62 to 75 bpm. In patient 2 the shock caused a persistent complete A-V block and neither antegrade nor retrograde conduction was observed during atrial and ventricular pacing. During a long episode of atrial flutter, there was a complete A-V block with a ventricular rate between 40 and 48 bpm. The follow-up is 9 months in both patients. We conclude that the technique used, which does not require open heart surgery, can be effectively used in patients with disabling supraventricular tachyarrhythmias resistant to drug treatment.

Amiodarone↗
PubMed1981

A comparison of clinical electrophysiologic studies in different institutions.

Although electrophysiologic studies have been used to evaluate tachycardia and AV conduction for over 10 years, there are no data comparing measurements obtained on the same patient studied in two institutions. We compared the records of 27 patients who underwent electrophysiologic studies at two different institutions and one patient studied twice in the same institution by two different investigators. We sought to determine if basic intervals, observed tachycardia, and diagnoses were comparable. We found no significant difference between the reported sinus cycle length, atrial-His interval, and His-ventricular interval when the patients were evaluated as a group. However, there were important measurement differences between the two studies in individual patients. The cycle length of induced tachycardias having similar QRS morphology and AV relation was also similar for the group, but individual patients again demonstrated important differences between the two studies. The diagnosis of the tachycardia varied in four patients. This report suggests that intracardiac recordings and the diagnosis of observed tachycardias are comparable among institutions studying the same patient when the group results are compared. However, individual patients demonstrate important measurement differences between the two institutions.

Adolescent↗
PubMed1981

His bundle interruption for control of inappropriate ventricular responses to atrial arrhythmias.

Forty-two patients with life-threatening or disabling atrial arrhythmias are discussed. Fifteen had Kent bundles as the basis for the reentry tachycardia, while 27 had arrhythmias that originated in or above the atrioventricular (AV) node. Nineteen of the latter had an AV node that conducted atrial impulses rapidly to the ventricle. These patients were classified as having enhanced conduction through the AV node, a diagnosis based on clinical and electrophysiological studies. Initially, the technique employed for His bundle interruption was, either separate or in combination, blind suture, electrocauterization, and incision of the septal portion of the right atrium. The technique later adopted was sharp division of the atrial septum at its attachment to the right fibrous trigone. Cryothermia was used in 31 patients. There were four failures. In the group in whom sharp division was used. there were two failures among 11 patients. Two patients, however, had to have a second operation. Following AV node-His bundle interruption, a junctional rhythm resulted and a pacemaker was always installed. Our studies indicate that interruption of atrial to ventricular conduction is a satisfactory operation for atrial arrhythmias that are disabling or life threatening and that are refractory to vigorous medical therapy. Cryothermic ablation is the preferable technique. However, if this is not successful, then division is required of the AV nod-His bundle junction by interruption of the insertion of the atrial septum into the right fibrous trigone.

Adolescent↗
PubMed1981

A digital timer for on-line interval measurement.

A digital timer suitable for on-line timing of cardiac intervals on a beat-by-beat basis is described in detail. The device expedites the process of on-line data acquisition and analysis of mapping and timing of atrial and/or ventricular multiple data points for electrophysiologic surgery. An unusual feature allows interval measurement between a fixed reference point and varying data points to be expressed as a positive value regardless of whether the data point occurs before or after the reference. This low-cost device is simple to operate and adds versatility to any existing analog recording system.

Electrocardiography↗
PubMed1981

The transition to ventricular fibrillation induced by reperfusion after acute ischemia in the dog: a period of organized epicardial activation.

Ventricular fibrillation was induced in eight of 10 open-chest dogs by reperfusion after a 15-minute occlusion of the proximal circumflex coronary artery. Simultaneous recordings were made from 27 epicardial electrodes spaced over both ventricles. Analysis of the initial 1.5--2.5 seconds of the transition from sinus rhythm or ventricular tachycardia to fibrillation revealed that ventricular activation occurred in an orderly, rapidly repeating sequence in all hearts. Each activation from arose near the border of the ischemic-reperfused region and passed across the nonischemic portion of the ventricles to the opposite side of the heart as a single, organized wavefront. As the arrhythmia progressed, the time between the appearance of successive activation fronts on the epicardium decreased. Concurrently, the time for each activation front to traverse the ventricles increased. The stimulation increase in rate of appearance and decrease in conduction velocity for each successive cycle resulted in overlapping cycles in which a new activation front arose from the ischemic-reperfused region before the previous front terminated over the right ventricle. The overlap between successive activation fronts increased as the arrhythmia continued. Thus, ventricular activation during the transition to ventricular fibrillation arose near the border of the ischemic-reperfused region and was organized as it passed across the nonischemic tissue, but the body surface ECG appeared disorganized because of variable spacing between successive, coexistent activation fronts.

Acute Disease↗
PubMed1981

Role of Mahaim fibers in cardiac arrhythmias in man.

Twelve patients with evidence of Mahaim fibers are reported, six with nodoventricular (NV) fibers and six with fasciculoventricular (FV) fibers. All patients with NV fibers had left bundle branch block morphology, and a sustained reentrant tachycardia with this morphology was proved in each case. In three of the six, ventriculoatrial dissociation occurred during tachycardia. We postulate that the mechanism of this tachycardia is a macroreentry circuit using the NV fiber for the antegrade limb and the His-Purkinje system with a portion of the atrioventricular node for the retrograde limb. ECGs of patients with FV fibers were varied, suggesting a functional relation to the right or left side of the septum. No direct relationship of FV fibers to observed arrhythmias could be found.

Adolescent↗
PubMed1981

Coronary sinus atrial pacing: radiographic considerations.

Transvenous atrial pacing via an electrode placed in the coronary sinus has become an increasingly frequent procedure during the past 10 years for both diagnosis and therapy of cardiac arrhythmias. The coronary sinus has five major venous tributaries, any one of which can be entered by a pacing catheter. A catheter in the middle cardiac vein can mimic the usual ventricular pacemaker position, while an electrode in the coronary sinus or in a persistent left superior vena cava may be mistaken for myocardial perforation. A persistent left superior vena cava may also be catheterized. This anomaly is associated with a tenfold increased incidence of congenital atrioventricular conduction abnormalities and, therefore, is surprisingly common in patients having coronary sinus pacers placed because of cardiac arrhythmias.

Adult↗
PubMed1981

The surgical approach to supraventricular arrhythmias.

The relatively small amount of experience with the surgical treatment of supraventricular tachycardias due to abnormalities other than a Kent bundle has been reviewed. The surgical procedure is direct but may not be definitive. With increasing knowledge concerning the nature of the arrhythmias as well as the identification of the site of the heart from which they originate, it is hoped that definitive operation will be possible. The experience at Duke with the surgical interruption of Kent pathways has now evolved to the point that the patient can be successfully treated at a low risk and with the promise of a satisfactory result.

Arrhythmias, Cardiac↗
PubMed1981

Surgical treatment of left free wall accessory pathways of atrioventricular conduction of the Kent type.

This report relates the surgical experience with 79 patients with arrhythmias who had 82 left free wall accessory pathways of atrioventricular conduction of the Kent type. The current operation for the interruption of the pathway consists of two steps. First, the localization of the pathway is done by mapping the epicardial excitation sequence of the atria and the ventricles. This is followed by a set group of maneuvers needed to divide the pathway, which is not visible or palpable. First, an endocardial atrial incision is made just above the anulus fibrosus extending 1.5 to 2.0 cm on each side of the pathway's crossing point. Then, a wide separation of the coronary sulcus fat from the atria and ventricles is done. Finally, superficial fibers of the ventricular myocardium are separated from the anulus fibrosus. The surgical problems such as the possible coronary sinus origin of a pathway and the proximity of pathways to the left fibrous trigone are discussed, both from the electrophysiological and the surgical standpoints. The overall success rate for interruption of left free wall pathways has been 90% with no failure in the last 34 patients.

Adolescent↗
PubMed1981

Surgical problems with multiple accessory pathways of atrioventricular conduction.

Thirty-six accessory pathways of atrioventricular conduction of the Kent type were found in 17 patients in a series of 161 patients subjected to direct operation for arrhythmias caused by the pathways. Careful preoperative studies detected the multiple pathways in 11 patients. In four patients, the additional pathways were found at operation, and in two patients they were found after operation. The operation successfully interrupted 32 of the 36 pathways. Multiple pathways must be sought for in all patients who are operated upon for arrhythmias caused by accessory pathways.

Adolescent↗
PubMed1981

[Familial sudden death in preexcitation syndrome. Surgical interruption of the anomalous pathways in two brothers (author's transl)].

We describe the results of surgical dissection of multiple accessory pathways in two brothers. A significant family history of pre-excitation syndrome was present: two children died suddenly and at the autopsy of one of them an accessory atrioventricular connection was found. In the first patient the preoperative electrophysiologic study showed anterior septal and posterior septal accessory pathways, and enhanced conduction in the A-V node. The second patient had the following anomalous connections: enhanced conduction in the A-V node; anterior septal, posterior septal and right lateral accessory pathways; Mahaim fiber. Intraoperative mapping, performed during pacing from different sites at different cycle length, was used to define the atrial and ventricular insertions of the accessory pathways as well as to confirm the surgical success.

Adolescent↗
PubMed1980

Arrhythmogenic epilepsy: an hypothesis.

This report describes a clinical syndrome of arrhythmias that may have neural origin. Two patients presented with episodes of loss of consciousness, disorientation, and paroxysmal supraventricular tachycardia (PSVT). One patient reported experiencing neurologic symptoms without tachycardia. When electrophysiologic testing with intracardiac recordings and programmed stimulation yielded no abnormalities that could account for the arrhythmias, a primary neurologic abnormality was sought. The electroencephalograms of both patients showed epileptiform discharges that supported this hypothesis. Arrhythmias and neurologic symptoms were controlled by treatment with the antiepileptic drug carbamazepine in one patient. Findings in these two patients suggest that in some patients arrhythmias may be a manifestation of seizures.

Adolescent↗
PubMed1980

Accessory atrioventricular pathway in an infant: prediction of location with body surface maps and ablation with cryosurgery.

A 10-month-old infant with multiple muscular ventricular septal defects, congestive heart failure, Wolff-Parkinson-White syndrome, and supraventricular tachycardia is presented. The site of ventricular pre-excitation was predicted by analysis of ST-T wave isopotential body surface maps to be in the posterior free wall of the right ventricle. The site was confirmed by epicardial mapping of the ventricles during surgery. The pathyway was cryoblated and the ventricular defects were closed. The patient has been free of pre-excitation and supraventricular tachycardia for over two years since surgery.

Animals↗