Accessory Conduction Research Articles

Diagnosis of accessory conduction pathway using ECG-Gated Emission CT analysis

Diagnosis of accessory conduction pathway using ECG-Gated Emission CT analysis

The Cardiac Pathology of Sudden, Unexplained Nocturnal Death in Southeast Asian Refugees

Sudden death during sleep has occurred among previously healthy Southeast Asian male refugees, but routine autopsies have not determined the cause of death in any of these cases. We report the first systematic attempt to define the cardiac abnormalities associated with this syndrome. Among 18 hearts examined, 14 showed slight to significant cardiomegaly, characteristic of increased cardiac work load. The reasons for the cardiomegaly remain unexplained. Conduction system anomalies were present in all but one heart. These included persistent fetal dispersion of the atrioventricular node and/or bundle of His, present in 14 hearts; accessory conduction fiber connections, found in 13 cases; and congenital heart block, observed in one case. These abnormalities were associated with variations in the structure of the cardiac base, suggesting a common aberrant developmental process. Although the functional significance of these findings has not been established, the conduction system anomalies may be the substrate for sleep-related cardiac arrhythmias and sudden death.

Radical surgical cure of Wolff-Parkinson-White syndrome: The Kanazawa experience

Between 1973 and 1983, we operated on 160 patients with Wolff-Parkinson-White syndrome at Kanazawa University Hospital; 126 had Wolff-Parkinson-White syndrome alone, and 34 had combined cardiac diseases. Of the 160 patients, 140 were completely cured; postoperatively, they had no delta wave on electrocardiograms and no tachycardia attacks. In 11 patients, the delta wave reappeared an average of 56 days after operation. They, and three other patients with concealed Wolff-Parkinson-White syndrome, experienced several postoperative episodes of tachycardia. However, in 12 of the 14 patients with postoperative tachycardia attacks, these disappeared completely in the course of a long follow-up period and these patients are also considered to be cured symptomatically. In the two remaining patients, the tachycardia attacks persisted. Of the 126 patients with Wolff-Parkinson-White syndrome alone, none died as a direct result of the operation. Patients with combined cardiac diseases other than cardiomyopathy, mild Ebstein's anomaly, or venous abnormality were treated in one operation. Six of the 34 patients with combined cardiac diseases died. In none of the 160 patients was the His bundle intentionally interrupted as an alternative method of interrupting the accessory conduction pathway. Our study showed that life-threatening arrhythmias occur more often than expected in patients with Wolff-Parkinson-White syndrome and the tolerance for tachycardia attacks differs from patient to patient. Because the surgical treatment of Wolff-Parkinson-White syndrome is safe and reliable, as indicated in this report, the radical correction of this disease should be considered in carefully evaluated patients.

Definitive operation for refractory cardiac tachyarrhythmias in children

A total of 114 children (age range 4 months to 18 years) underwent definitive operation for life-threatening or incessant tachydysrhythmias resulting from accessory conduction pathways (Kent bundle) (79), atrial ectopic foci (18), or ventricular ectopic foci (17). Of the patients with the accessory pathway type of supraventricular tachycardia, 63.3% (50/79) had classical Wolff-Parkinson-White syndrome whereas 36.7% (29/79) had retrograde conduction only across the pathway. Locations of the pathways were as follows: left posterior 48.1% (38/79), right anterior or lateral 27.8% (22/79), posterior septal 16.5% (13/79), anterior septal 3.8% (3/79), and both right and left 3.8% (3/79). With increasing experience, the success rate (cure of tachycardia) improved from 85% in the first 40 patients to 95% in the last 40 patients. One surgical death (1.3%) occurred secondary to a paradoxical air embolus. Atrial ectopic tachycardia was treated by cryoablation (nine), excision (one), combined excision and cryoablation (six), and atrial disconnection (two). The ectopic focus was located on the right atrial wall in 13 patients (72.2%) and cardiopulmonary bypass was required in eight (44.4%). The operation was successful in 89%; two patients with multiple ectopic foci continued to have uncontrolled tachycardia after the operation. Ventricular tachycardia presenting in the first 2 years of life was due to gross tumor in three cases (rhabdomyoma two, fibroma one) or microscopic hamartomatous change (Purkinje tumor) in five cases and was treated by excision alone or with adjuvant cryoablation. In four cases no tumor was found but the area of ectopic focus was successfully cryoablated. One child with diffuse endocardial tumor died of low cardiac output after the operation. Ventricular tachycardia in older children was localized to outflow patch aneurysms or other areas in the right ventricle following tetralogy of Fallot repair (three patients, treated by excision or cryoablation) and arrhythmogenic right ventricular dysplasia (two patients, treated by right ventricular disconnection). We conclude that mapping and operation for supraventricular tachycardia resulting from accessory pathways are predictable and curative in a high percentage of patients. Atrial ectopic tachycardias are more difficult to precisely localize but can be cured by a combination of excisional and cryoablative techniques. Ventricular tachycardia in infants is lethal and is commonly due to ectopic foci or microscopic tumors that may not be apparent on preoperative angiography or echocardiography. Electrophysiologically directed operations in these patients can be lifesaving.

Nuclear tomographic phase analysis: Localization of accessory conduction pathway in patients with Wolff-Parkinson-White syndrome

The purpose of this study was to evaluate the usefulness of tomographic phase analysis in detecting the site of the accessory conduction pathway (ACP) in patients with Wolff-Parkinson-White (WPW) syndrome. Gated emission computed tomography and planar gated blood pool scintigraphy were performed in 20 patients with WPW syndrome, 14 with delta waves and six without delta waves (two intermittent types and four concealed types). The abnormal initial contractions in both planar and tomographic phase images were compared with the sites of ACPs confirmed by epicardial mapping and surgery. The atrioventricular ring was divided into eight segments on each side, and the identification of the initial phase in the segment in which the ACP was located, or that adjacent to it, was considered to be the correct diagnosis. In planar phase analysis, the abnormal initial phase was identified correctly in 8 of 14 patients (57%), whereas in tomographic phase analysis, the site of the ACP was detected in 12 of 14 patients (86%). Tomographic phase analysis can be a helpful adjunctive method in patients with WPW syndrome.

Mechanisms of junctional tachycardia showing ventricular pre-excitation.

Over a period of five years 12 patients underwent electrophysiological studies for the investigation of recurrent tachycardias which showed ventricular pre-excitation. Nine patients had a type B pattern and two a type A. One patient had episodes of both types. Dual atrioventricular nodal pathways were found in six of seven patients with atrioventricular nodal re-entrant tachycardia mechanisms. Single direct atrioventricular accessory pathways were present in four patients, single nodoventricular pathways in five, and multiple pathways in three. Twenty one tachycardias were induced, of which 13 showed ventricular pre-excitation. Five patients had nodoventricular pathway conduction during atrioventricular nodal tachycardia and one during atrioventricular re-entrant tachycardia. Only three patients had simple antidromic tachycardia and one additional atrioventricular nodal tachycardia with bystander atrioventricular accessory conduction. Three patients had three different tachycardias, three had two types, and six had one type. Thus junctional tachycardias showing ventricular pre-excitation are often associated with multiple mechanisms and complex anatomical and functional substrates. An accessory pathway was an essential component in only six of 13 tachycardias showing ventricular pre-excitation. Determination of the tachycardia mechanism requires detailed study and analysis.

Accessory atrioventricular conduction pathway with long conduction time, combined with an antidromic reciprocating tachycardia-an uncommon type in the Wolff-Parkinson-White syndrome

Accessory atrioventricular conduction pathway with long conduction time, combined with an antidromic reciprocating tachycardia-an uncommon type in the Wolff-Parkinson-White syndrome

Surgical treatment of the Wolff-Parkinson-White syndrome in infants and children.

Eleven pediatric Wolff-Parkinson-White (WPW) syndrome patients underwent surgery. Four had left, 5 right cardiac type and 2 had right septal type WPW syndrome. Two patients had 2 accessory conduction pathways (ACP). Ebstein's anomaly and secundum type atrial septal defect were the association congenital cardiac diseases in one patient each. Indications for surgery included repeated and/or long-lasting paroxysmal supraventricular tachycardia (PSVT), ineffective drug therapy, cardiac failure due to frequent tachycardia, short effective refractory period of the ACP, and simultaneous surgery for associated congenital cardiac diseases. Pre- and intra-operative examinations, including ECG, VCG, UCG, body surface mapping, intracavitary recording by catheter electrodes, computerized epicardial mapping, and endocardial mapping, were performed for the precise localization of the ACP. The surgical method was basically the same as is used for adults. Anterior median stermotomy was used primarily in right cardiac and right septal type and left anterior thoracotomy was used in 3 of 4 cases of the left cardiac type. Eight of 11 cases, two of which had 3 ACPs, were completely cured and in 3 there was evidence of postoperative pre-excitation. However, the PSVT attacks disappeared almost completely and drug therapy is not required at present.

Correlation between localization of accessory conduction pathway and body surface maps in the Wolff-Parkinson-White syndrome.

Body surface maps were recorded in 26 patients with Wolff-Parkinson-White syndrome, who underwent successful localization and interruption of the accessory conduction pathway. Five types of body surface maps were classified according to the location of the potential maximum and minimum in the delta wave. These 5 types were left free wall type, left posterior septal type, right posterior septal type, right anterior septal type and right free wall type. Each type correlated well with the location of the accessory pathway, which was determined intraoperatively through epicardial and/or endocardial maps or surgical interruption. The potential minimum zone at 40 msec after the onset of the delta wave appeared at limited areas on the body surface, and this zone was divided into 7 areas which correspond to the location of the accessory pathway.

Interruption of Multiple Accessory Conduction Pathways in the Wolff-Parkinson-White Syndrome

Of 35 patients with Wolff-Parkinson-White syndrome operated on, 5 were seen with two accessory conduction pathways each; all of these were successfully interrupted. In one patient, one accessory conduction pathway each was located in the right and left side of the heart; in the other 4, both pathways were confined to the right side. In 2 patients with unilateral (right side) multiple accessory conduction pathways, Ebstein's anomaly was also present. In 1 patient with Ebstein's anomaly, the second unilateral accessory conduction pathway was discovered intraoperatively and was successfully interrupted. The remaining 4 patients required a second operation to interrupt the other pathway. A delta wave completely different from the preoperative one appeared 4 to 10 days after interruption of the first major pathway, and the second operation was performed 14 days, 42 days, four months, or five years after the first operation. All 5 patients survived, and long-term follow-up revealed no signs of morbidity.

Localization and interruption of accessory conduction pathway in the Wolff-Parkinson-White syndrome

We operated upon 36 patients with Wolff-Parkinson-White (WPW) syndrome between 1969 and July, 1979. The relationship between the electrocardiogram (ECG), particularly the delta wave, and localization of the accessory conduction pathway (ACP) was analyzed, and the value of preoperative examinations such as vectorcardiography, echocardiography, body surface mapping, intracavitary potential study, and cardiac pacing were demonstrated. Epicardial mapping was indispensable as an intraoperative study and represented the most effective method for localizing the ACP. In some cases, endocarial potential study was found to be efficacious. Detachment of the atrium from the ventricle by an incision along the anulus at the area of earliest pre-excitation, resulted in complete correction in 26 of 28 patients operated upon between 1973 and July, 1979. In five patients multiple ACPs was corrected, although four of them required a second operation. The surgical indications in the WPW syndrome should be expanded in view of the high success rate and the safety of the operation.

Interruption of multiple accessory conduction pathways in the Wolff-Parkinson-White syndrome

Interruption of multiple accessory conduction pathways in the Wolff-Parkinson-White syndrome

Predicting the location of accessory atrioventricular conduction pathways in infants and children

Predicting the location of accessory atrioventricular conduction pathways in infants and children

Management of arrhythmias due to accessory conduction pathways.

Pacing and Clinical ElectrophysiologyVolume 1, Issue 4 p. 481-487 Management of Arrhythmias Due to Accessory Conduction Pathways ANDREW M. TONKIN, Corresponding Author ANDREW M. TONKIN Department of Medicine, Flinders Medical Centre. Bedford Park, AustraliaAddress for reprints: Dr. A.M. Tonkin, Department of Medicine. Flinders Medical Centre. Bedford Park SA 5042. Australia.Search for more papers by this author ANDREW M. TONKIN, Corresponding Author ANDREW M. TONKIN Department of Medicine, Flinders Medical Centre. Bedford Park, AustraliaAddress for reprints: Dr. A.M. Tonkin, Department of Medicine. Flinders Medical Centre. Bedford Park SA 5042. Australia.Search for more papers by this author First published: October 1978 https://doi.org/10.1111/j.1540-8159.1978.tb03511.xCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume1, Issue4October 1978Pages 481-487 RelatedInformation

Recurrent tachycardias due to an accessory pathway

A 48 year old female presented with a long history of palpitations and syncopal episodes. His bundle electrogram studies were performed in order to evaluate the conduction system. The electrocardiogram (ECG) revealed normal PR and QRS intervals, while the unpaced His electrogram was normal. With atrial pacing rates of 110 to 180 beats/min, the AH and HV intervals remained essentially unchanged. This signifies that there was an accessory conduction pathway which bypassed the AV node. Thus, pre-excitation can not be eliminated as a diagnostic possibility even if the ECG is normal.

The Electrophysiologic Studies on Wolff-Parkinson-White (WPW) Syndrome : With Special Reference to His Bundle Pacing on WPW Syndrome

For a long time many theories have been postulated with regard to the cause of WPW syndrome, more than 60, according to Scherf and Cohen. But the accessory bundle theory is mostly accepted as the outcome of anatomically proved accessory conduction pathway, the result of epicardial mapping for type B WPW syndrome and the therapeutic results obtained by the interruption of accessory conduction pathway. The author has attempted to examine functional property of the accessory conduction pathway of WP syndrome using the His bundle electrogram, atrial pacing and the His bundle pacing. Functional evaluation on the accessory conduction pathway is not only important for clarifying the mechanism of WPW syndrome, but also it is particularly important when surgical interruption of the accessory conduction pathway is attempted. Up to the present there has been no repot of successful His bundle pacing in many cases of WPW syndrome, so in this paper the author will mainly report the findings obtained by the His bundle pacing on WPW syndrome. Materials and Methods: Twenty patients were studied. All patients had the typical WPW pattern, i.e., a shortened PQ interval, delta wave and a widened QRS complex. It involves 10 cases of type A and 10 cases of type B. the technics of His bundle electrogram recording introduced by Scherlag and co-workers were used. A bipolar electrode catheter (distance between electrodes is 10mm) was introduced through the right femoral vein under local anesthesia and was positioned fluoroscopically close to the septal leaflet of the tricuspid valve. Another bipolar electrode catheter was introduced through the same vein and was positioned above the right atrium, and it was used for atrial pacing the recording of high right atriogram.

The Wolff-Parkinson-White syndrome: problems in evaluation and surgical therapy.

Two patients with WPW syndrome underwent surgery to ablate accessory conduction pathways. Endocardial and epicardial mapping in both patients had indicated an area of early right ventricular depolarization. Surgical transection of the areas of early depolarization failed in both cases to normalize the electrocardiogram. In the first patient, additional resection in the area of the A-V node failed to produce heart block and the ECG remained abnormal. However, the paroxysmal tachycardia ceased, and she has remained asymptomatic and active 12 months after surgery. In the second patient, as the A-V node was about to be sectioned, pressure and procaine near the A-V node caused the ECG to normalize transiently and after resection permanently. Microscopic study of this tissue showed "P cells." Postoperatively the patient demonstrated normal A-V nodal function. He was discharged with a normal ECG but expired soon after discharge. Postmortem examination of the heart demonstrated the A-V node and bundle of His plus the location of the resection adjacent to the bundle of His. These two cases illustrate disparities between electrophysiologic mapping and actual site of the accessory conduction pathway. In one of the cases an accessory bundle was demonstrated histologically.

The Wolff-Parkinson-White syndrome: Problems in evaluation and surgical therapy

Two patients with WPW syndrome underwent surgery to ablate accessory conduction pathways. Endocardial and epicardial mapping in both patients had indicated an area of early right ventricular depolarization. Surgical transection of the areas of early depolarization failed in both cases to normalize the electrocardiogram. In the first patient, additional resection in the area of the A-V node failed to produce heart block and the ECG remained abnormal. However, the paroxysmal tachycardia ceased, and she has remained asymptomatic and active 12 months after surgery. In the second patient, as the A-V node was about to be sectioned, pressure and procaine near the A-V node caused the ECG to normalize transiently and after resection permanently. Microscopic study of this tissue showed P cells. Postoperatively the patient demonstrated normal A-V nodal function. He was discharged with a normal ECG but expired soon after discharge. Postmortem examination of the heart demonstrated the A-V node and bundle of His plus the location of the resection adjacent to the bundle of His. These two cases illustrate disparities between electrophysiologic mapping and actual site of the accessory conduction pathway. In one of the cases an accessory bundle was demonstrated histologically.

Concealed right bundle branch block in the presence of Type B ventricular pre-excitation

A 10-year-old boy is presented in whom complete RBBB is masked by Type B WPW syndrome. The spontaneous occurrence of this phenomenon parallels what has been demonstrated in the catheterization laboratory by stimulating the ventricular septum and producing RBBB only when Type B WPW is absent. This finding supports the contention that pre-excitation is conducted by means of a separate accessory conduction pathway connecting the right atrium and right ventricle. The presence of simultaneous Type B pre-excitation and right intraventricular block reported in patients with Ebstein's disease is explained as resulting from peripheral conduction defects rather than central bundle branch block.

Surgically induced atrioventricular block as treatment for recurrent atrial tachycardia in Wolff-Parkinson-White syndrome.

In a 60-year-old male with WPW syndrome and recurrent PAT refractory to cardiac drugs, surgical creation of complete A-V block without cardiopulmonary bypass has prevented recurrence of the PAT. The findings in this case support the accessory conduction tissue theory as being responsible for WPW conduction in some patients and a circus re-entry movement as responsible for the recurring PAT.