ABSTRACT
BACKGROUND: Distinguishing between junctional tachycardia (JT) and atrioventricular nodal reentrant tachycardia (AVNRT) is essential to minimize unnecessary catheter ablation and the risk of heart block during treatment of AVNRT. OBJECTIVE: The purpose of this study was to investigate whether the tachycardia response to atrial overdrive pacing at a cycle length (CL) slightly shorter than tachycardia CL can differentiate between JT and AVNRT. We hypothesized that atrial overdrive pacing would transiently suppress JT but would entrain AVNRT. METHODS: Twenty-one patients in whom AVNRT was induced and atrial overdrive pacing during either AVNRT or JT was attempted were included in the study. We predicted that, upon cessation of atrial overdrive pacing, an atrial-His-His-atrial (AHHA) response would identify JT and an atrial-His-atrial (AHA) response would identify AVNRT. RESULTS: A total of 8 JT and 21 typical AVNRT were induced. Atrial overdrive pacing was attempted in all cases of JT and in 16 cases of AVNRT. An AHHA response was observed in 100% (8/8) of JT cases. In 2 cases of AVNRT, atrial overdrive pacing repetitively terminated the tachycardia. In the remaining patients with AVNRT, an AHA response was observed in 100% (14/14) of cases. When a response was able to be elicited, atrial overdrive pacing was 100% sensitive and 100% specific for differentiating JT from AVNRT. CONCLUSION: Atrial overdrive pacing during tachycardia can rapidly differentiate JT from AVNRT, which can improve the safety and efficiency of catheter ablation of these arrhythmias.
Subject(s)
Cardiac Pacing, Artificial/methods , Catheter Ablation/methods , Tachycardia, Atrioventricular Nodal Reentry/diagnosis , Tachycardia, Ectopic Junctional/diagnosis , Adult , Aged , Aged, 80 and over , Diagnosis, Differential , Electrophysiologic Techniques, Cardiac/methods , Female , Humans , Male , Middle Aged , Tachycardia, Ectopic Junctional/physiopathology , Tachycardia, Ectopic Junctional/therapy , Treatment OutcomeSubject(s)
Tachycardia, Supraventricular , Anti-Arrhythmia Agents/therapeutic use , Atrial Flutter/diagnosis , Atrial Flutter/therapy , Cardiac Pacing, Artificial , Catheter Ablation , Costs and Cost Analysis , Diagnosis, Differential , Electrocardiography , Electrophysiologic Techniques, Cardiac , Female , Heart Conduction System/physiopathology , Heart Defects, Congenital/complications , Humans , Male , Pregnancy , Pregnancy Complications, Cardiovascular/diagnosis , Pregnancy Complications, Cardiovascular/therapy , Quality of Life , Tachycardia, Atrioventricular Nodal Reentry/diagnosis , Tachycardia, Atrioventricular Nodal Reentry/therapy , Tachycardia, Ectopic Atrial/diagnosis , Tachycardia, Ectopic Atrial/therapy , Tachycardia, Ectopic Junctional/diagnosis , Tachycardia, Ectopic Junctional/therapy , Tachycardia, Paroxysmal/diagnosis , Tachycardia, Paroxysmal/therapy , Tachycardia, Sinus/diagnosis , Tachycardia, Sinus/therapy , Tachycardia, Supraventricular/diagnosis , Tachycardia, Supraventricular/epidemiology , Tachycardia, Supraventricular/therapyABSTRACT
Focal junctional tachycardia (FJT) is characterized by a rapid often irregular narrow complex tachycardia with episodes of atrioventricular (AV) dissociation. This uncommon arrhythmia is most likely due to abnormal automaticity or triggered activity. The patients are often quite symptomatic and if left untreated may develop heart failure particularly if their tachycardia is incessant. In patients refractory to medical management, the role of radiofrequency ablation involves either (1) selective ablation of the tachycardia focus while preserving AV conduction or as a last resort (2) AV junction ablation followed by pacemaker implantation. The clinician should first assess whether ventriculoatrial (VA) conduction is present or absent during tachycardia. If present, radiofrequency ablation should be applied at the site of earliest retrograde atrial activation. In the absence of VA conduction and hence an atrial target site, sequential lesions should be applied in the posterior septum (slow pathway region) followed by lesions applied in midseptum and anteroseptum respectively if tachycardia persists. To further minimize the risk of AV nodal block, some authors delivered radiofrequency energy during atrial overdrive pacing to assess AV conduction during ablation. Others recommended mapping the perinodal region and applying radiofrequency ablation at the site where catheter manipulation resulted in tachycardia termination. Using this ablative approach, the risk of AV block is around 5-10%.
Subject(s)
Atrioventricular Node/surgery , Catheter Ablation/methods , Electrophysiologic Techniques, Cardiac/methods , Tachycardia, Atrioventricular Nodal Reentry/diagnosis , Tachycardia, Ectopic Junctional/diagnosis , Tachycardia, Ectopic Junctional/therapy , Adult , Atrioventricular Node/physiopathology , Catheter Ablation/adverse effects , Controlled Clinical Trials as Topic , Diagnosis, Differential , Electrocardiography/methods , Evaluation Studies as Topic , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pacemaker, Artificial , Recurrence , Risk Assessment , Sensitivity and Specificity , Severity of Illness Index , Treatment OutcomeABSTRACT
Junctional ectopic tachycardia (JET) is one of the most life-threatening postoperative arrhythmias in children with congenital heart disease, and medical management is difficult. Paired ventricular pacing (PVP) may provide a safe alternative mode of management. We evaluated the safety and efficacy of PVP for the management of postoperative JET in patients with congenital heart disease. A retrospective collection of data was done from 1981-1995. PVP was successfully tried in five postoperative patients (age range: 37 days to 22 years, median: 10 months). Onset of JET was 3-60 hours (mean +/- SD, 19 +/- 23 hours) postoperatively. The maximal JET rate was 261 +/- 39 beats/min. PVP was used as the first line of management in three patients and was successful in all patients. It resulted in an instantaneous increase in blood pressure from 66 +/- 9 to 94 +/- 15 mmHg (42% increase) and was required for 12 +/- 14 hours (range 2-36 hours). No complications were noted. Therefore, in our experience, this is a safe alternative modality for the control of postoperative JET.
Subject(s)
Cardiac Pacing, Artificial/methods , Cardiac Surgical Procedures/adverse effects , Heart Defects, Congenital/surgery , Tachycardia, Ectopic Junctional/therapy , Adult , Child , Electrocardiography , Female , Follow-Up Studies , Heart Rate , Humans , Infant , Postoperative Complications/etiology , Postoperative Complications/therapy , Retrospective Studies , Tachycardia, Ectopic Junctional/etiology , Tachycardia, Ectopic Junctional/physiopathologyABSTRACT
The ability of four vagotonic physical manoeuvres to terminate paroxysmal junctional tachycardias was tested in 35 patients with inducible and sustained arrhythmia. Each manoeuvre was used up to three times in an attempt to terminate an induced tachycardia and was judged to be effective if it terminated two out of the three induced episodes. The Valsalva manoeuvre in the supine position was effective in 19 (54%), right carotid sinus massage in 6 (17%), left carotid sinus massage in 2 (5%), and the diving reflex in 6 (17%) cases. 4 of the 6 patients who responded to right carotid sinus massage and all patients who responded to the diving reflex also responded to the Valsalva manoeuvre. The Valsalva manoeuvre while standing was effective in 9 (20%) patients only. Patients in whom the manoeuvres terminated the tachycardias were significantly younger than those who did not respond (median age: 30 vs 45 years, p less than 0.01). Physical manoeuvres were much more successful in terminating atrioventricular re-entry tachycardias (19/24) than atrioventricular nodal re-entry tachycardias (3/11, p less than 0.01). Efficacy of the manoeuvres was related to their bradycardic effect in sinus rhythm.