Anti-Arrhythmia Agents ; therapeutic use ; Child ; Humans ; Tachycardia, Atrioventricular Nodal Reentry ; drug therapy ; Tachycardia, Ectopic Atrial ; drug therapy ; Tachycardia, Ectopic Junctional ; drug therapy ; Tachycardia, Supraventricular ; drug therapy ; Tachycardia, Ventricular ; drug therapy

BACKGROUND AND OBJECTIVES: The mechanisms of supraventricular tachycardia (SVT) in children are known to have age-dependent distributions. However, the distribution of the mechanisms of tachyarrhythmia, as a whole, is not known in infants and children. The aim of this study was to evaluate the mechanisms of tachyarrhythmia in infants with a structurally normal heart. SUBJECTS AND METHODS: We retrospectively reviewed the mechanisms of tachycardia in 56 children with structurally normal hearts, who had had a tachyarrhythmia in infancy. The mechanisms of tachycardia were confirmed in surface electrocardiogram and by transesophageal, or transvenous, electrophysiological study. RESULTS: The majority of tachycardia during infancy were SVT, in 50 of the 56 (89%). In the infants with SVT, 29 (58%) had atrioventricular reentrant tachycardia using an accessory pathway, With a manifested accessory pathway were in 13 of the 29. Primary atrial tachycardia was found in 19 (38%: a chaotic atrial tachycardia in 10, an atrial flutter in 5 and an atrial ectopic tachycardia in 4). 6 (11%) had a ventricular tachycardia, and of these 5 had a verapamil-sensitive idiopathic left ventricular tachycardia. The most infrequent tachycardia during infancy was an atrioventricular nodal reentrant tachycardia, which occurred in only 2 (4%). 39% of the tachycardia during infancy occurred in the neonatal period. Atrioventricular nodal reentrant and ventricular tachycardia were not found during the neonatal period. CONCLUSION: The most frequent mechanism of tachycardia during infancy was SVT related, with an accessory pathway. Primary atrial and ventricular tachycardia were also found in nearly half the infants, and these were sometimes difficult to manage without understanding their precise mechanism.
Atrial Flutter ; Child ; Electrocardiography ; Heart* ; Humans ; Infant* ; Retrospective Studies ; Tachycardia* ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Ectopic Atrial ; Tachycardia, Supraventricular ; Tachycardia, Ventricular

Among patients with Wolff-Parkinson-White syndrome, atrioventricular reciprocating tachycardia (AVRT) and atrioventricular nodal reentrant tachycardia (AVNRT) can coexist in a single patient. Direct transition of both tachycardias is rare; however, it can occur after premature atrial or ventricular activity if the cycle lengths of the two tachycardias are similar. Furthermore, persistent atrial activation by an accessory pathway (AP) located outside of the AV node during ongoing AVNRT is also rare. This article describes a case of uncommon atrial activation by an AP during AVNRT and gradual transition of the two supraventricular tachycardias without any preceding atrial or ventricular activity in a patient with preexcitation syndrome.
Atrioventricular Node ; Humans ; Pre-Excitation Syndromes ; Tachycardia* ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Paroxysmal ; Tachycardia, Reciprocating ; Tachycardia, Supraventricular ; Wolff-Parkinson-White Syndrome*

OBJECTIVES: Accurate diagnosis of the mechanism and origin site of paroxysmal supraventricular tachycardia(PSVT) can be made using electrophysiologic study(EPS). Recently, radiofrequency catheter ablation technique has been introduced and widely used for the definitive treatment of various forms of PSVT, thereby precise determination of the mechanism of PSVT can be possible. It has been known that atrioventricular reentry tachycardia (AVRT) using concealed bypass tract is more frequent than atrioventricular nodal reentry tachycardia (AVNRT) in Korea. But it is not certain that those studies represent actual distribution of PSVT in Korea. This study was designed to determine the mechanism and clinical characteristics of PSVT in Korea. METHODS: We investigated 136patients in whom electrophysiolosic study was performed from October 1992 through October 1994 at the Chonnam National University Hospital, the only tertiary referral center of the Kwangju-Chonnam area of Korea. RESULTS: 1) The electrophysiologic mechanism of PSVT was AVNRT in 44patients(32.4%), WPW syndrome in 46(33.8%), AVRT using concealed bypass tract in 40(29.4%), sinoatrial nodal reentry tachycardia (SANRT) in 4(2.9%), and automatic atrial tachycardia(AAT) in 2(1.5%), ensuing that AVNRT is most common mechanism of PSVT with no preexcitation during sinus rhythm. 2) Male is more frequent than female in AVNRT, WPW syndrome, and AVRT, which was most prominent in WPW syndrome. 3) The first episode of symptom occured at the age of 34.9 +/- 17.3 years in AVNRT, 25.5 +/- 13.3 years in WPW and 26.3 +/- 15.0 years in AVRT(p<0.05). There was no significant difference in the duration of symptom. The tachycardia rate in WPW syndrome was 183.6 +/- 23.9 per minute and AVRT was 186.7 +/- 38.0 per minute, which were faster than that of AVNRT(161.7 +/- 28.6/min)(p<0.05). 4) There was no significant difference in the presenting symptoms and in the provocation factors between AVNRT and AVRT. CONCLUSION: AVNIlT is most common mechanism of PSVT with no preexcitation during sinus rhythm, developed at older age than WPW syndorme and AVRT, and had lower tachycardia rate than WPW syndrome and AVRT.
Catheter Ablation ; Diagnosis ; Female ; Humans ; Jeollanam-do ; Korea ; Male ; Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Sinoatrial Nodal Reentry ; Tachycardia, Supraventricular* ; Tertiary Care Centers ; Wolff-Parkinson-White Syndrome

The delivery of single His-refractory ventricular extra-stimulus during supraventricular tachycardia is useful to identify the mechanism of the tachycardia. We present the different responses based on the ventricular extra-stimulus site. Our findings demonstrate that the atrial activation via an accessory pathway was not advanced based on the ventricular pacing site. Therefore, atrioventricular tachycardia could masquerade as atrioventricular nodal reentrant tachycardia.
Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Supraventricular*

Anterograde and retrograde conduction properties of dual AV nodal pathways were analyzed in 15 patients having no accessory pathway and showing dual AV nodal pathways during extrastimulation. Four patients in whom the supraventricular tachycardia of common type (common type SVT) was induced during electrophysiological study were classified into group A. The remained 11 patients in whom the common type SVT was not induced were classified into group B. There was a history of paroxysmal supraventricular tachycardia(PSVT) in all of group A but none of group B. Among the properties of dual AV nodal pathways, effective refractory period (ERP) of anterograde fast pathway (FP) and retrograde FP were not different in both group. Maximal AH interval of anterograde slow pathway (SP) was significantly shorter in group A than in group B (P<0.01). In group A, all patients had intact ventriculoatrial (VA) conduction, but in group B, 5 patients had no VA conduction. The paced atrial cycle length producing Wenckebach block (WBCL) and the paced ventricular cycle length producing retrograde VA block (VABCL) were significantly shorter in group A the in group B (p<0.05). There were two patients showing retrograde dual AV nodal pathways. The common type SVT was not induced in both of them probably due to long ERP of retrograde FP. In conclusion, in patients with anterograde dual AV nodal pathways, the occurrence of common type SVT is highly related to anterograde slow pathway refractoriness (WBCL) and retrograde fast patway refactoriness (VABCL).
Humans ; Tachycardia, Atrioventricular Nodal Reentry* ; Tachycardia, Supraventricular

BACKGROUND AND OBJECTIVES: We performed a retrospective study to elucidate the frequency of tachycardia mechanisms and the characteristics of accessory pathways (APs), confirmed by radiofrequency catheter ablation (RFCA) in pediatric tachycardia. In addition, we analyzed the efficacy and safety of pediatric RFCA. SUBJECTS AND METHODS: The authors retrospectively reviewed the records of a total of 260 patients (aged 2 to 18 years) who had undergone RFCA between August 1993 and July 2011 at two medical centers in Daegu. RESULTS: Two hundred and sixty patients underwent 272 RFCAs at less than 18 years of age. Of these 260 patients, 9 patients (3%) were younger than 6 years, and 175 patients (67%) were older than 12 years. The tachycardia mechanisms observed were atrioventricular reentry tachycardia (AVRT) in 175 patients (65%), atrioventricular nodal reentry tachycardia (AVNRT) in 83 patients (30%), ventricular tachycardia in 12 patients (4%), and atrial tachycardia in 2 patients (0.7%). Among the patients with AVRT, there were 94 concealed APs and 81 manifest APs. Left-side APs were more common in concealed APs than in manifest APs (72/94, 77% vs. 33/81, 41%, p<0.001). Sixty-six percent (55/83) of AVNRT cases were located at the M1 and/or M2 sites. Four patients had multiple tachycardia mechanisms (AVNRT+AVRT) and 9 patients had multiple APs. The recurrence rate was 5% (13/272). Of these recurrent cases, 12 patients had AVRT. The overall success rate was 95%. CONCLUSION: Pediatric RFCA provides a good success rate and an acceptable recurrence. In addition, we suggest that the APs location may be associated with concealed or manifest property of APs.
Catheter Ablation ; Catheters ; Humans ; Pediatrics ; Recurrence ; Retrospective Studies ; Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Supraventricular ; Tachycardia, Ventricular

Atrioventricular nodal reentrant tachycardia is the most common type of supraventricular tachycardia. The initiation and maintenance of tachycardia is caused by the characteristic anatomic and electrophysiologic properties of the atrioverntricular node. Acute management for the termination of tachycardia includes pharmacologic and non-pharmacologic management. There are several options for preventing recurrence of tachycardia, and radiofrequency ablation for modulation of tachycardia circuit can be considered as a primary strategy. A thorough understanding of the unique electrophysiologic features is very essential for optimal management and best possible outcome in cases of invasive management.
Catheter Ablation ; Recurrence ; Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry* ; Tachycardia, Supraventricular

BACKGROUND: Retrograde P wave can be found not only in atrioventricular reentrant tachycardia (AVRT) but also in atrioventricular nodal reentrant tachycardia (AVNRT), especially of posterior-type. This study evaluated the usefulness of retrograde P wave for differentiating AVNRT from concealed AVRT and for localization of accessory pathway(AP). METHODS: Twelve lead ECGs were analyzed in patients with AVNRT (n=41) and concealed AVRT (n=53) who have taken successful ablation. Presence of pseudo r' in V1, pseudo S in II, III, aVF, and configuration and polarity of presumed retrograde P waves were evaluated. RP was obtained by subtracting RP interval in III from that in V1. RESULTS: In anterior-type AVNRTs (n=38), there were no retrograde P wave in 53% and the pseudo r' and/or S in 47%. Retrograde P waves in V1 were positive in 67% (2/3 cases) of posterior-type AVNRTs and 97.4% (37/38 cases) of AVRTs with left free wall AP, but negative in 83.3% (5/6 cases) of AVRTs with right free wall AP. Retrograde P waves in II, III, aVF were negative in all of posterior-type AVNRTs, all with left and right posteroseptal AP, right posterior AP, and 90% (9/10 cases) with left posterior AP. All with left anterior and right anteroseptal AP showed positive P wave in III. RP of posterior-type AVNRT was significantly larger than those with left posteroseptal or left posterior AP (p<0.01). Sensitivity of newly developed stepwise algorithm was 50-100%. CONCLUSION: Retrograde P wave during tachycardia on standard ECG is very useful for differentiation of AVNRT from concealed AVRT and also for localization of APs.
Electrocardiography ; Humans ; Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Supraventricular*

Reentrant tachycardias can often be terminated by discrete pacing stimuli that penetrate the reentrant circuit. Antitachycardia pacemaker PASAR 4172 (Programmable Automatic Scanning Arrhythmia Reversion, Model 4172, Telectronics) is designed to detect tachycardia automatically and subsequently to deliver programmed one or two extrastimuli to revert to sinus rhythm. We experienced two patients, one paroxysmal supraventricular tachycardia and one paroxysmal ventricular tachycardia, who had had frequent and often prolonged episodes of tachycardia that responded poorly to pharmacologic antiarrhythmic therapy. Each patient underwent a detailed preimplantation clinical electrophysiological study in order to determine the number of stimuli required for termination of tachycardia, the most satisfactory site for electrode placement, and the tachycardia termination zone. During the follow-up period of 7 to 11 months after implantation of PASAR 4172, no patient complained of an episode of sustained tachycardia although they experienced symptoms of an impending attack. We conclude that antitachycardia pacemaker PASAR 4172 is a safe, effective, and well tolerated method for the therapy of drug resistant paroxysmal supraventricular tachycardia and paroxysmal ventricular tachycardia.
Arrhythmias, Cardiac ; Electrodes ; Follow-Up Studies ; Humans ; Tachycardia ; Tachycardia, Paroxysmal* ; Tachycardia, Supraventricular ; Tachycardia, Ventricular