Clinical Study Of Atrioventricular Nodal Diameter

Part I Long-Term Efficacy of Empirical Slow Pathway Ablation in Noninducible and Suspected Atrioventricular Nodal Reentry TachycardiaBackground:The empirical slow pathway ablation(ESPA) is often applied to noninducible and suspected atrioventricular nodal reentrant tachycardia(AVNRT) patients. The long-term efficacy of ESPA in these patients is not entirely clear.Methods:From January 2005 through December 2013, all patients underwent slow pathway ablation were evaluated. Based on whether AVNRT could be induced, patients were divided into group A(AVNRT inducible) and group B(AVNRT noninducible). Telephone communication, letter questionnaire and clinic visit were conducted for long-term follow up, Recurrence was based on symptoms and/or ECG documentation.Results:622 patients underwent slow pathway ablation (median age 48 years old,56.8% female) were included in the study.488 patients were divided into group A and 134 into group B. In a median follow up of 31 mouths, the recurrence rate was similar between group A(7.4%) and group B(9.0%) (p>0.05), the recurrence rate due to supraventricular tachycardia (SVT) and other arrhythmias respectively was also similar between groups(P>0.05). In group B, the recurrence rate of patients without tachycardia ECG documentation before ablation was higher than those with tachycardia ECG documentation(p=0.033), Logistic regression analyses showed that no tachycardia ECG documentation before ablation was a significant prognostic predictor for recurrence(P=0.019).1 major complication occurred in group A and no complication occurred in group B.Conclusion:ESPA can be performed safely and effectively in noninducible and suspected AVNRT patients with good long-term results, no tachycardia ECG documentation before ablation is predictive for recurrence in these patients.Part II The clinical significance of dual atrioventricular node physiology in atrioventricular reentry tachycardiaIntroduction:The coexistence of dual atrioventricular node physiology(DAVNP) in invasive electrophysiological study (EPS) is not uncommon in atrioventricular nodal reentrant tachycardia (AVRT) patients. Whether this phenomenon increase the risk of recurrence of superventricular tachycardia is not unknown.Methods:From September 2014 through Augest 2015, all AVRT patients underwent accessory pathways ablation were evaluated. Based on whether DAVNP was exist, patients were divided into group A(DAVNP existence) and group B(DAVNP nonexistence). Telephone communication, letter questionnaire and clinic visit were conducted for long-term follow up, Recurrence was based on symptoms and/or ECG documentation.Results:123 patients underwent accessory pathways ablation(median age 41 years old,44.7% female) were included in the study.51 patients were divided into group A and 72 patients were divided into group B. The baseline characteristics reveal 39% of which are overt accessory pathways,66.7% of the accessory pathways located in left side and 66.7% in right side.41.5% were coexistence with DAVNP. The acute success rate is 99.2%.In a median follow up of 368 days, there were 2(1.6%) recurrence due to PSVT. the recurrence rate was similar between group A and group B (2.0% vs.1.4%) (P=1.000). no complication occurred in both groups.Conclusions:The coexistence of DAVNP in EPS is not uncommon in AVRT patients which does not increase the risk of recurrence of superventricular tachycardia.Part III Fixed HV interval and Pre-excitation Degree during AH Interval Jumps Help to Confirm the Diagnosis of Fasciculoventricular PathwayIntroduction:Fasciculoventricular(FV) pathway is an uncommon pre-excitation variant. We reported a case of FV pathway, concomitant atrioventricular accessory pathway as well as dual atrioventricular node physiology(DAVNP).Methods and results:A 32-year-old woman was admitted to our hospital with a chief complain of intermittent palpitation for 15 years. Physical examination as well as chest X-ray and transthoracic echocardiogram were normal.12-lead electrogram showed minimal pre-excitation. Tachycardia was induced by invasive electrophysiology examination demonstrating atrioventricular reentrant tachycardia. After the left side atrioventricular accessory pathway was successfully ablated minimal preexcitation on 12-lead ECG still exists. Intracardiac electrogram revealed that HV interval=24 ms. The ablation catheter was then placed to high right atrium and programmed atrial stimulation was applied from the ablation catheter demonstrating DAVNP with AH interval jumps of 120 ms without change in the degree of HV interval and pre-excitation degree, furthermore, adenosine was administered to block atrioventricular node conduction and the junctional rhythm was presented, the pre-excitation morphology in 12-lead electrogram was not changed compared with those in sinus rhythm, suggesting a FV pathway.Conclusions:We reported a case of FV pathway, atrioventricular accessory pathway as well as AVNDP. Fixed HV interval and Pre-excitation degree during AH interval jumps help to confirm the diagnosis of fasciculoventricular pathway.