Discontinuation of cardiac implantable electronic device therapy after transvenous lead extraction

BACKGROUND

Patients with cardiac implantable electronic devices (CIEDs) may no longer be eligible for continued therapy.

AIMS

The study aimed to assess the circumstances under which CIED reimplantation may not be necessary after transvenous lead extraction (TLE).

METHODS

A retrospective analysis of 3646 TLE procedures was performed with assessment of indications for device reimplantation.

RESULTS

Reimplantation was not performed immediately after TLE in 169 (4.6%) and, in long-term follow-up, in 146 (4.0%) of patients. No further need for CIED reimplantation was mostly associated with establishment of stable sinus rhythm (2.4%), conversion of sinus node dysfunction to chronic atrial fibrillation (AF; 1.4%), or improvement in left ventricular ejection fraction (LVEF) (0.9%). Independent prognostic factors were in the pacing groups: LVEF (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.05; P <0.001), AF (OR, 3.8; 95% CI, 2.4-15.7; P <0.001), patients' age during first CIED implantation (OR, 0.97; 95% C, 0.96-0.98; P <0.001), and New York Heart Association (NYHA) class (OR, 0.616; 95% CI, 0.43-0.86; P <0.01); in the cardioverter-defibrillator group: LVEF (OR, 1.06; 95% CI, 1.04-1.09; P <001). Non-reimplanted patients had more complex procedures and more frequent complications, but survival after TLE was better in this group of patients.

CONCLUSIONS

Reassessment of the need for continuation of CIED therapy should be considered in all patients following lead extraction and also before planned device replacement as TLE delay increases implant duration, complexity, and procedural risk. The predictors of non-reimplantation are a younger age during the first CIED implantation, lower NYHA class, presence of AF, and higher LVEF in pacemaker carriers, and, in the defibrillator group, only higher LVEF. A decision not to reimplant does not negatively affect the long-term prognosis.

Shared Decision Making and Cardioneuroablation Allow Discontinuation of Permanent Pacing in Patients with Vagally Mediated Bradycardia

BACKGROUND

Safe discontinuation of pacemaker therapy for vagally mediated bradycardia is a dilemma. The aim of the study was to present the outcomes of a proposed diagnostic and therapeutic process aimed at discontinuing or not restoring pacemaker therapy (PPM) in patients with vagally mediated bradycardia.

METHODS

The study group consisted of two subgroups of patients with suspected vagally mediated bradycardia who were considered to have PPM discontinued or not to restore their PPM if cardioneuroablation (CNA) would successfully treat their bradycardia. A group of 3 patients had just their pacemaker explanted but reimplantation was suggested, and 17 patients had preexisting pacemakers implanted. An invasive electrophysiology study was performed. If EPS was negative, extracardiac vagal nerve stimulation (ECVS) was performed. Then, patients with positive ECVS received CNA. Patients with an implanted pacemaker had it programmed to pace at the lowest possible rate. After the observational period and control EPS including ECVS, redo-CNA was performed if pauses were induced. The decision to explant the pacemaker was obtained based on shared decision making (SDM).

RESULTS

After initial clinical and electrophysiological evaluation, 17 patients were deemed eligible for CNA (which was then performed). During the observational period after the initial CNA, all 17 patients were clinically asymptomatic. The subsequent invasive evaluation with ECVS resulted in pause induction in seven (41%) patients, and these patients underwent redo-CNA. Then, SDM resulted in the discontinuation of pacemaker therapy or a decision to not perform pacemaker reimplantation in all the patients after CAN. The pacemaker was explanted in 12 patients post-CNA, while in 2 patients explantation was postponed. During a median follow-up of 18 (IQR: 8-22) months, recurrent syncope did not occur in the CNA recipients.

CONCLUSIONS

Pacemaker therapy in patients with vagally mediated bradycardia could be discontinued safely after CNA.

Amateur Athlete with Sinus Arrest and Severe Bradycardia Diagnosed through a Heart Rate Monitor: A Six-Year Observation-The Necessity of Shared Decision-Making in Heart Rhythm Therapy Management

Heart rate monitors (HRMs) are used by millions of athletes worldwide to monitor exercise intensity and heart rate (HR) during training. This case report presents a 34-year-old male amateur soccer player with severe bradycardia who accidentally identified numerous pauses of over 4 s (maximum length: 7.3 s) during sleep on his own HRM with a heart rate variability (HRV) function. Simultaneous HRM and Holter ECG recordings were performed in an outpatient clinic, finding consistent 6.3 s sinus arrests (SA) with bradycardia of 33 beats/min. During the patient's hospitalization for a transient ischemic attack, the longest pauses on the Holter ECG were recorded, and he was suggested to undergo pacemaker implantation. He then reduced the volume/intensity of exercise for 4 years. Afterward, he spent 2 years without any regular training due to depression. After these 6 years, another Holter ECG test was performed in our center, not confirming the aforementioned disturbances and showing a tendency to tachycardia. The significant SA was resolved after a period of detraining. The case indicates that considering invasive therapy was unreasonable, and patient-centered care and shared decision-making play a key role in cardiac pacing therapy. In addition, some sports HRM with an HRV function can help diagnose bradyarrhythmia, both in professional and amateur athletes.

Association between the geographic region and the risk of familial atrioventricular nodal reentrant tachycardia in the Polish population

INTRODUCTION Atrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common regular supraventricular arrhythmias referred for catheter ablation (CA). In Poland, several families with familial AVNRT (FAVNRT) were reported in Podkarpacie Province (PP). OBJECTIVES We aimed to determine the frequency of FAVNRT in PP compared with other south‑eastern provinces of Poland. PATIENTS AND METHODS Clinical data of 1544 patients with AVNRT diagnosed by invasive electrophysi-ological study between 2010 and 2019 were screened for FAVNRT. From January 2017 to June 2019, patients were asked to provide details on family history and origin to obtain 3‑generation pedigrees. Families with at least 2 members with previous CA of AVNRT were divided into those from south‑eastern provinces (SEPs; including PP and bordering provinces [BPs]) and the remaining parts of Poland (RPP). RESULTS There were 932 patients from SEPs and 612 from RPP. FAVNRT was reported in 45 patients (2.91%) from 27 families, with a higher frequency in SEPs than RPP (4.02% vs 1.17%; P = 0.002) and the highest frequency in PP (6.33% vs 2.47% in BPs; P = 0.004). The risk of FAVNRT was higher in PP compared with BPs (odds ratio, 2.67; 95% CI, 1.36-5.23; P = 0.004) and similar in BPs compared with RPP (odds ratio, 2.14; 95% CI, 0.86-5.34; P = 0.1). CONCLUSIONS A relationship exists between the geographic region and frequency of FAVNRT. A greater distance from PP was associated with less frequent FAVNRT. International cooperation and genetic test-ing are needed to confirm the genetic impact of FAVNRT in this part of Central Europe.

Implementation of zero or near-zero fluoroscopy catheter ablation for idiopathic ventricular arrhythmia originating from the aortic sinus cusp

Complete elimination of fluoroscopy during radiofrequency ablation (RFA) of idiopathic ventricular arrhythmias (IVAs) originating from the aortic sinus cusp (ASC) is challenging. The aim was to assess the feasibility, safety and a learning curve for a zero-fluoroscopy (ZF) approach in centers using near-zero fluoroscopy (NOX) approach in IVA-ASC. Between 2012 and 2018, we retrospectively enrolled 104 IVA-ASC patients referred for ZF RFA or NOX using a 3-dimensional electroanatomic (3D-EAM) system (Ensite, Velocity, Abbott, USA). Acute, short and long-term outcomes and learning curve for the ZF were evaluated. ZF was completed in 62 of 75 cases (83%) and NOX in 32 of 32 cases (100%). In 13 cases ZF was changed to NOX. No significant differences were found in success rates between ZF and NOX, no major complications were noted. The median procedure and fluoroscopy times were 65.0 [45-81] and 0.0 [0-5] min respectively, being shorter for ZF than for NOX. With growing experience, the preference for ZF significantly increased-43% (23/54) in 2012-2016 vs 98% (52/53) in 2017-2018, with a simultaneous reduction in the procedure time. ZF ablation can be completed in almost all patients with IVA-ASC by operators with previous experience in the NOX approach, and after appropriate training, it was a preferred ablation technique. The ZF approach for IVA-ASC guided by 3D-EAM has a similar feasibility, safety, and effectiveness to the NOX approach.

Ultrasound-guided imaging for vagus nerve stimulation to facilitate cardioneuroablation for the treatment of functional advanced atrioventricular block

We present a case study article demonstrating successful implementation of ultrasound guided extra cardiac vagus nerve stimulation during cardioneuroablation.

To our knowledge it is first published description of this technique, as most ECVS are done in the internal jugular vein bulb area. This method allows for reduction of fluoroscopy time, and most importantly reproducible vagus nerve capture especially after full bi-nodal (sinus and atrioventricular) cardioneuroablation when stimulation of vagus nerve may not give any effect in the heart. This article includes a case study with “dual component” atrioventricular block, where functional component is cured with cardioneuroablation, but structural (PR elongation) remains after procedure.

Non-invasive and invasive autonomic tests to facilitate cardioneuroablation and complex indications for transcutaneous lead extraction and discontinuation of permanent pacing

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Rare-A-Care registry

Background

 Extracardiac vagal nerve stimulation (ECANS) and cardioneuroablation (CNA) are promising methods to cure vagally mediated bradycardia and validate indications for permanent pacing for sinus node dysfunction (SND), atrioventricular blocks (AVB), tachycardia-bradycardia syndrome (TBS) and cardio-inhibitory or mixed reflex syncope (VVS). There are limited information on clinical utility of those procedures in validation of indication for continuation of permanent pacing (PM) and transcutaneous lead extraction (TLE).

Methods

 Data were collected from prospective multicentre registry of CNA facilitated by interdisciplinary consultations, state-of-art autonomic tests, atropine/propranolol tests, electrophysiologic study as well as ECANS. Share-decision making were used by EP-HEART-TEAM to developed patient-oriented therapy.

Results

 Between June 2018-Jan 2021 the first 102 consecutive patients underwent interdisciplinary approach before invasive EPS and/or invasive ECANS, to consider biatrial, binodal CNA, if possible to cure functional bradycardia. Eleven (10%) patients had implanted permanent PM"s due to SND/AVB/TBS/CI-VVS and were considered for TLE. In 2 out of 11 cases CNA was not performed due to: 1) structural advanced 2nd and 3rd degree AVB with indication for TLE and permanent HBP (no.1), 2) incidental severely symptomatic persistent 3rd degree AVB more than 15 year ago without any further bradycardia episodes (only TLE, no.2). In further 9 of 11 cases with PM CNA was performed, however TLE was not attempted in 2 patients [(SND + PVC ablation + indication for beta-blocker therapy due to IHD in older male. TLE had not yet been attempted to confirm long-term success therapy by patient and/or physician (no.3); two periprocedural successful CNA resulted in disappearance of CI reflex however  despite pacing syncopal events persist due to mixed etiology (no.4)]. In further 7/11 cases TLE-s were performed. Three cases had TLE prior to CNA [VVS-CI + advanced functional AVB - prior 3 pacemaker reimplantations and further "rescue" CNA, (no.5); CI-VVS + pacemaker infection (no.6); TLE of PM + TBS no.7]. Finally, in 4 cases TLE was recommended after CNA [CI-VVS (no.8, no.9 and no.10); mixed etiology: TBS + VVS-CI + intermittent, recurrent pericardial efffusion due to lead perforation, PM syndrome, (no. 11)]. 

Conclusions

 Interdisciplinary and comprehensive autonomic approach with ECANS and CNA enable EP-HEART-TEAM to offer patient-oriented therapy with a complex clinical scenarios before final decision about TLE and discontinuation of permanent pacing therapy.

Cardiac parasympathetic modulation in the setting of radiofrequency ablation for atrial fibrillation

The cardiac autonomic nervous system plays an important role in the genesis and maintenance of atrial fibrillation. Although, pulmonary vein isolation is the cornerstone in today's approach to atrial fibrillation ablation, a considerable proportion of patients will recur with atrial arrhythmias following this procedure, especially in the non-paroxysmal forms. The pulmonary vein isolation indirectly targets and ablate the ganglionated plexi. This might ultimately enhance the efficacy of the procedure, but an optimal ablation strategy and a reliable method to confirm and quantify the efficacy of vagal denervation following the procedure might be necessary, thus leading to significantly better results.

Fluoroless catheter ablation of supraventricular and ventricular arrhythmias in pregnancy: validation of a standard approach in a large multicenter registry

Background

An increasing experience in zero- (ZF) or near-zero fluoroscopy catheter ablation (CA) supports the implementation of early, fluoroless approach for recurrent, symptomatic arrhythmias in pregnancy.

Purpose

The aim of the study was to evaluate the feasibility, efficacy, and safety of CA with a standardized ZF approach during pregnancy.

Methods

Data were derived from a large prospective multicenter registry (ELEKTRO-RARE-A-CAREgistry). Between 2012 and 2019, more than 2655 CA procedures were performed in women in intention-to-treat using a ZF fluoroscopy approach. The procedures were performer using: 1) femoral access, 2) double-catheter technique, without intracardiac echocardiography, 3) electroanatomic mapping system (Ensite, Abbott, USA) for mapping and navigation, 4) conscious, light sedation. Shared decision making approach was applied, including a pregnancy heart team consultations.

Results

The study group consisted of 18 pregnant women (mean age: 30.3±5.0 years; range: 19–38 years; mean gestational age during CA: 21.4±9.2 weeks; range: 7–36 weeks). All pregnant women had no overt structural heart disease. Among women in reproductive age, pregnant women referred for ZF-CA approach accounted for approximately 2% of procedures. In the study group, the major indications for

CA included: AVNRT (n=10); OAVRT/WPW (n=2); focal idiopathic ventricular arrhythmia (n=4), AT (n=1) and AF (n=1). Five women had double substrate for CA. In AF case general anesthesia and transesophageal echocardiography were used to monitor ZF-transseptal puncture and right-sided pulmonary vein isolation. All procedures were successfully completed without fluoroscopy, and without serious maternal or fetal complications. The procedure and ablation application times were 55.0±30.0 min and 394±338 s, respectively. In one patient second procedure for idiopathic ventricular arrhythmia was postponed after delivery.

Conclusion

Implementation of pregnancy heart team and a standard fluoroless protocol for CA in daily electrophysiological practice allowed an early, safe, and effective CA of maternal supraventricular tachycardia and idiopathic ventricular arrhythmias in pregnancy.

Funding Acknowledgement

Type of funding source: None

Catheter ablation of the cavotricuspid isthmus in patients with atrial flutter: predictors of long-term outcomes

BACKGROUND

Predictors of long‑term outcomes and an optimal catheter set for ablation of the cavotricuspid isthmus in patients with atrial flutter (AFL) are not well known.

AIMS

This study aimed to identify predictors of clinical events following ablation.

METHODS

We studied 741 patients (mean [SD] age, 62.2 [10.8] years; 248 women) who were followed for a mean (SD) time of 4.4 (2.7) years. The 2- versus 3‑electrode approach and clinical predictors ofclinical events during follow‑up were analyzed.

RESULTS

The 2‑electrode approach was faster (mean [SD] time, 62.5 [30.3] vs 101.4 [51] min; P <0.001), associated with shorter fluoroscopy time (13.1 [9.3] vs 20.3 [12.4] min; P < 0.001), cost‑effective (8.29 [2.82] vs 11.89 [2.51] units; P <0.001), and more effective (92.1% vs 86.1%; P = 0.012). The independent predictors of AFL recurrence were: calcium blocker use (hazard ratio [HR], 3.24; 95% CI, 1.64-6.4), mitral valve disease (HR, 1.82; 95% CI, 1.12-2.95), previous stroke and/ or TIA (HR, 2.38; 95% CI, 1.21-4.65), pulmonary artery dilatation (HR, 3.94; 95% CI, 1.22-12.73), and previous pulmonary embolism (HR, 3.77; 95% CI, 1.14-12.43); of atrial fibrillation (AF): previous AF (HR, 6.054; 95% CI, 4.58-8), left atrial enlargement (HR, 1.43; 95% CI, 1.12-1.81), number of antiarrhythmic drugs used (HR, 1.16; 95% CI, 1.05-1.28), and mitral valve disease (HR, 1.28; 95% CI, 1.04-1.58); of pacemaker implantation: tachycardia‑bradycardia syndrome (HR, 6.17; 95% CI, 3.16-12.05), previous second-/third‑degree atrioventricular block (HR, 29.4; 95% CI, 7.37-117.28), centrally acting hypotensive drugs (HR, 29.55; 95% CI, 6.14-142.25), aortic dilatation or aneurysm (HR, 2.58; 95% CI, 1.06-6.3), a labile international normalized ratio (HR, 3.45; 95% CI, 1.72-6.93), left bundle branch block (HR, 4.7; 95% CI, 1.49-14.82), the shortest R‑R interval during AFL (HR, 1.003; 95% CI, 1.001-1.005), previous cardiac surgery (HR, 2.69; 95% CI, 1.27-5.7), and aortic valve disease (HR, 2.22; 95% CI, 1.08-4.59).

CONCLUSION

Ablation of cavotricuspid isthmus with a minimal number of electrodes is safe and effective. Specific predictors of clinical events during long‑term follow-up can be determined.

Cough as a Cause and Consequence of Heart Dysfunction - Current State of Art

The cough reflex is an airway defensive process that can be modulated by afferent inputs from organs located also out of the respiratory system. A bidirectional relationship between cough and heart dysfunctions are presented in the article, with the special insights into an arrhythmia-triggered cough. Albeit rare, cough induced by cardiac pathologies (mainly arrhythmias) seems to be an interesting and underestimated phenomenon. This condition is usually associated with the presence of abnormal heart rhythms and ceases with successful treatment of arrhythmia either by pharmacotherapy or by radiofrequency ablation of arrhythmogenic substrate. The two main hypotheses on cough-heart relationships - reflex and hemodynamic - are discussed in the review, including the authors' perspective based on the experiences with an arrhythmia-triggered cough.

Outcomes in patients with dual antegrade conduction in the atrioventricular node: insights from a multicentre observational study

BACKGROUND

Supraventricular tachycardias induced by dual antegrade conduction via the atrioventricular (AV) node are rare but often misdiagnosed with severe consequences for the affected patients. As long-term follow-up in these patients was not available so far, this study investigates outcomes in patients with dual antegrade conduction in the AV node.

METHODS AND RESULTS

In this multicentre observational study, patients from six European centres were studied. Catheter ablation was performed in 17 patients (52 ± 16 years) with dual antegrade conduction via both AV nodal pathways between 2012 and 2018. Patients with the final diagnosis of a manifest dual AV nodal non-re-entrant tachycardia had a mean delay of the correct diagnosis of over 1 year (range 2-31 months). Two patients received prescription of non-indicated oral anticoagulation, two further patients suffered from inappropriate shocks of an implantable cardioverter defibrillator. In 12 patients, a co-existence of dual antegrade and re-entry conduction in the AV node was present. Mean fast pathway conduction time was 138 ± 61 ms and mean slow pathway conduction time was 593 ± 134 ms. Successful radiofrequency catheter ablation was performed in all patients. Post-procedurally oral anticoagulation was discontinued, without detection of cerebrovascular events or atrial fibrillation during a long-term follow-up of median 17 months (range 6-72 months).

CONCLUSION

This first multicentre study investigating patients with supraventricular tachycardia and dual antegrade conduction in the AV node demonstrates that catheter ablation is safe and effective while long-term patient outcome is good. Autonomic tone dependent changes in ante- vs. retrograde conduction via slow and/or fast pathway can challenge the diagnosis and therapy in some patients.

Feasibility and performance of catheter ablation with zero-fluoroscopy approach for regular supraventricular tachycardia in patients with structural and/or congenital heart disease

Patients with structural heart disease (SHD) are more difficult to ablate than those with a structurally healthy heart. The reason may be technical problems. We compared periprocedural data in unselected patients (including SHD group) recruited for zero-fluoroscopy catheter ablation (ZF-CA) of supraventricular arrhythmias (SVTs).Consecutive adult patients with atrioventricular nodal reentry tachycardia (AVNRT), accessory pathways (AP), atrial flutter (AFL), and atrial tachycardia (AT) were recruited. A 3-dimensional electroanatomical mapping system (Ensite Velocity, NavX, St Jude Medical, Lake Bluff, Illinois) was used to create electroanatomical maps and navigate catheters. Fluoroscopy was used on the decision of the first operator after 5 minutes of unresolved problems.Of the 1280 patients ablated with the intention to be treated with ZF approach, 174 (13.6%) patients with SHD (age: 58.2 ± 13.6; AVNRT: 23.9%; AP: 8.5%; AFL: 61.4%; and AT: 6.2%) were recruited. These patients were compared with the 1106 patients with nonstructural heart disease (NSHD) (age: 51.4 ± 16.4; AVNRT: 58.0%; AP: 17.6%; AFL: 20.7%; and AT: 3.7% P ≤ .001). Procedural time (49.9 ± 24.6 vs 49.1 ± 23.9 minutes, P = .55) and number of applications were similar between groups (P = 0.08). The rate of conversion from ZF-CA to fluoroscopy was slightly higher in SHD as compared to NSHD (13.2% vs 7.8%, P = .02) while the total time of fluoroscopy and radiation doses were comparable in the group of SHD and NSHD (P = .55; P = .48).ZF-CA is feasible and safe in majority of patients with SHD and should be incorporated into a standard approach for SHD; however, the procedure requires sufficient experience.

5202Zero- or near-zero fluoroscopy radiofrequency catheter ablation for aortic sinus cusp idiopathic ventricular arrhythmias

Background

Complete elimination of fluoroscopy during radiofrequency catheter ablation (RFCA) of idiopathic ventricular arrhythmias (IVA) originating from aortic sinus cusp (ASC) may be challenging, requires confirmation of coronary arteries ostia and could be associated with potential risk of collateral damage and severe complications.

Purpose

To validate the implementation, feasibility, learning curve, safety and efficacy of zero-fluoroscopy (ZF) approach in centers using near-zero fluoroscopy (NOX) approach for RFCA of idiopathic premature ventricular complexes/ventricular tachycardias (PVCs/VTs) from ASC.

Methods

From 2012 to 2018, we prospectively enrolled 106 consecutive patients (age: 49±19, males: 58%, children: 7%, 108 PVC/VT focuses from ASC, PVCs/24h: 23808±22006) with ASC-IVA. Patients were unselected and referred for ZF or NOX approach using three dimensional electroanatomic system- 3D EAM without intracardiac or transesophageal echocardiography. The choice of ZF and NOX was based on the first operator experience and from 2014 three experienced operators and three fellows performed ZF as an intention-to-treat approach. The peri-procedural, short-term outcome as well as learning curve of ZF in ASC were evaluated with documentation of reasons for cross-over to NOX approach.

Results

Out of 108 focuses there were majority of left coronary cusps and left/right junctions sites of origin [other rare locations: right coronary cusp (n=7); non-coronary cusp, n=6)]. On intention-to-treat 61/76 (80%) cases were completed without fluoroscopy in ZF-approach. Additionally, 30/30 (100%) cases were completed with NOX. The main reasons for fluoroscopy use in ZF approach (conversion to NOX) were: the need for elective valsalvography plus coronary angiography (n=6), urgent coronary angiography due to validation of transient uncomplicated coronary spasms and ST elevation (n=2), catheter stability checking (n=2), femoral access site confirmation (n=1) and navigation problem (n=1). No significant differences were found in the acute and short-term success rates between ZF and NOX (90% vs 88%, P=NS) and no major complications occurred. The procedure time, fluoroscopy time and ablation time were 66.8±26.9; 3.6±7.2 and 7.3±5.5 min, respectively. The gathering experience of ZF approach, computer-assisted ECG analysis and 3D-EAM reconstruction of aortic root and coronary artery ostia resulted in significant reduction of NOX approach between early and late period [median (n=53): 2012–2016 vs 2017–2018, 40/53 (76%) vs 5/53 (8%), p<0.001].

Conclusion

ZF can be completed in majority of patients with ASC-IVA especially after appropriate training and operators' experience with NOX. ZF approach guided by 3D-EAM is feasible, safe, and effective for treatment of ASC-IVA with importance of training and preprocedural imaging for exclusion of coronary anomalies or validation of coronary arteries ostia by 3D-EAM.

A simplified approach for evaluating sustained slow pathway conduction for diagnosis and treatment of atrioventricular nodal reentry tachycardia in children and adults

PURPOSE

During incremental atrial pacing in patients with atrioventricular nodal reentrant tachycardia, the PR interval often exceeds the RR interval (PR > RR) during stable 1:1 AV conduction. However, the PR/RR ratio has never been evaluated in a large group of patients with pacing from the proximal coronary sinus and after isoproterenol challenge. Our study validates new site of pacing and easier method of identification of PR > RR.

MATERIAL AND METHODS

A prospective protocol of incremental atrial pacing from the proximal coronary sinus was carried out in 398 patients (AVNRT-228 and control-170). The maximum stimulus to the Q wave interval (S-Q = PR), SS interval (S-S), and Q-Q (RR) interval were measured at baseline and 10 min after successful slow pathway ablation and after isoproterenol challenge (obligatory).

RESULTS

The mean maximum PR/RR ratios at baseline were 1.17 ± 0.24 and 0.82 ± 0.13 (p < 0.00001) in the AVNRT and controls respectively. There were no PR/RR ratios ≥1 at baseline and after isoproterenol challenge in 12.3% of the AVNRT group and in 95.9% of the control group (p < 0.0001). PR/RR ratios ≥1 were absent in 98% of AVNRT cases after slow pathway ablation/modification in children and 99% of such cases in adults (P = NS). The diagnostic performance of PR/RR ratio evaluation before and after isoproterenol challenge had the highest diagnostic performance for AVNRT with PR/RR > = 1 (sensitivity: 88%, specificity: 96%, PPV-97%, NPV-85%).

CONCLUSIONS

The PR/RR ratio is a simple tool for slow pathway substrate and AVNRT evaluation. Eliminating PR/RR ratios ≥1 may serve as a surrogate endpoint for slow pathway ablation in children and adults with AVNRT.

Noninvasive assessment of left atrial fibrosis. Correlation between echocardiography, biomarkers, and electroanatomical mapping

AIM

Left atrial (LA) fibrosis promotes atrial fibrillation (AF), may predict poor radiofrequency catheter ablation (RFCA) outcome, and may be assessed invasively using electroanatomical mapping (EAM). Speckle tracking echocardiography (STE) enables quantitative assessment of LA function. The aim was to assess the relationship between LA fibrosis derived from EAM and LA echocardiographic parameters as well as biomarkers of fibrosis in patients with AF.

METHODS

Sixty-six patients (64% males, mean age 56 ± 10) with nonvalvular AF treated with first RFCA were prospectively studied. Seventy-three percent of patients were in sinus rhythm at the time of examination. LA geometry, systolic, and diastolic function were assessed. In STE global, peak atrial longitudinal (PALS) and contractile (PACS) strain were calculated. LA stiffness index (LAs) - the ratio of E/e' to PALS - was assessed. The EAM of LA was build using Carto System before RFCA. Low amplitude potentials area (LAPA) was quantitatively analyzed and expressed as a percentage of LA surface using the cut-off <0.5 mV to detect potential sites of fibrosis. The serum concentrations of MMP-9, PIIINP, and TGFβ1were estimated before RFCA.

RESULTS

Pearson correlation analysis showed a significant correlation between LA diastolic function parameters: PALS (-0.54, P < .001), LAs (0.65, P < .001), and LAPA in patients who were in sinus rhythm. Also LA volume significantly correlated with LAPA (0.44, P < .002). None of biomarkers correlated with LAPA.

CONCLUSION

Left atrial diastolic parameters derived from STE correlate well with the extent of LA fibrosis. Thus, STE may be useful in the noninvasive assessment of LA fibrosis and selection of candidates for RFCA.

Maximum voltage gradient technique for optimization of ablation for typical atrial flutter with zero-fluoroscopy approach

Radiofrequency catheter ablation (RFCA) is an established effective method for the treatment of typical cavo-tricuspid isthmus (CTI)-dependent atrial flutter (AFL). The introduction of 3-dimensional electro-anatomic systems enables RFCA without fluoroscopy (No-X-Ray [NXR]). The aim of this study was to evaluate the feasibility and effectiveness of CTI RFCA during implementation of the NXR approach and the maximum voltage-guided (MVG) technique for ablation of AFL.Data were obtained from prospective standardized multicenter ablation registry. Consecutive patients with the first RFCA for CTI-dependent AFL were recruited. Two navigation approaches (NXR and fluoroscopy based as low as reasonable achievable [ALARA]) and 2 mapping and ablation techniques (MVG and pull-back technique [PBT]) were assessed. NXR + MVG (n  =  164; age: 63.7 ± 9.5; 30% women), NXR + PBT (n  =  55; age: 63.9 ± 10.7; 39% women); ALARA + MVG (n  =  36; age: 64.2 ± 9.6; 39% women); and ALARA + PBT (n  =  205; age: 64.7 ± 9.1; 30% women) were compared, respectively. All groups were simplified with a 2-catheter femoral approach using 8-mm gold tip catheters (Osypka AG, Germany or Biotronik, Germany) with 15 min of observation. The MVG technique was performed using step-by-step application by mapping the largest atrial signals within the CTI.Bidirectional block in CTI was achieved in 99% of all patients (P  =  NS, between groups). In NXR + MVG and NXR + PBT groups, the procedure time decreased (45.4 ± 17.6 and 47.2 ± 15.7 min vs. 52.6 ± 23.7 and 59.8 ± 24.0 min, P < .01) as compared to ALARA + MVG and ALARA + PBT subgroups. In NXR + MVG and NXR + PBT groups, 91% and 98% of the procedures were performed with complete elimination of fluoroscopy. The NXR approach was associated with a significant reduction in fluoroscopy exposure (from 0.2 ± 1.1 [NXR + PBT] and 0.3 ± 1.6 [NXR + MVG] to 7.7 ± 6.0 min [ALARA + MVG] and 9.1 ± 7.2 min [ALARA + PBT], P < .001). The total application time significantly decreased in the MVG technique subgroup both in NXR and ALARA (P < .01). No major complications were observed in either groups.Complete elimination of fluoroscopy is feasible, safe, and effective during RFCA of CTI in almost all AFL patients without cardiac implanted electronic devices. The most optimal method for RFCA of CTI-dependent AFL seems to be MVG; however, it required validation of optimal RFCA's parameters with clinical follow-up.

Electrocardiographic Parameters Indicating Worse Evolution in Patients with Acquired Long QT Syndrome and Torsades de Pointes

BACKGROUND

Acquired long QT syndrome (a-LQTS) is associated with life-threatening ventricular arrhythmias, mainly torsades de pointes (TdP). ECG parameters predicting evolving into ventricular fibrillation (VF) are ill defined.

AIMS

To determine ECG parameters preceding and during TdP associated with higher risk of developing VF.

METHODS

We analyzed 151 episodes of TdP, recorded in 28 patients with a-LQTS (mean QTc 638 ms ± 57).

RESULTS

All 28 patients had prolonged QT interval, (mean QTc 638 ms ± 57) ranging from 502 ms to 858 ms correcting by Bazett's formula. The mean TdP heart rate was 218 bpm ± 38 (mean cycle length of TdP 274 ± 47 ms). We classified TdPs episodes into "slower"-TdP (s-TdP) < 220 bpm (range from 145-220 bpm) observed in 81 (53.6%) episodes and "faster"-TdP (f-TdP) ≥ 220 bpm (ranged from 221-281 bpm) observed in 70 (46.4%) episodes. Among 151 episodes of TdP, 21 (13.9%) were unstable (converted into VF). Out of 81 episodes of "slower"-TdP only 2 (2.5%) episodes converted into VF. The mean coupling interval (CI) of the PVC initiating TdP was 510 ms ± 118, the pause-RR interval was 1147 ms ± 335, the prematurity index (PI) of PVC that initiated TdP was 0.45 ± 0.13. The mean cycle length variability of TdP (VRV-TdP) was 30.79 ms ± 19.7. U wave was observed in 86 episodes (56.9%), among that in 69 episodes, the U/T wave ratio was > 1. Macro T wave alternans was observed in 4 patients. The QT interval was not different in patients with VF(+) and VF(-) episodes, 633 ± 60 and 639 ± 57, respectively.

CONCLUSIONS

Some electrocardiographic parameters can be helpful in determining the risk of TdP evolving into VF. The slower ventricular rate (< 220 bpm), the higher rate instability (VRV > 30 ms) and the short episodes < 20 beats could predict benign evolution.

Left Ventricular Diastolic Dysfunction Assessed by Conventional Echocardiography and Spectral Tissue Doppler Imaging in Adolescents With Arterial Hypertension

Compared to conventional echocardiography, spectral tissue Doppler imaging (s-TDI) allows more precise evaluation of diastolic cardiac function. The purpose of this study was to conduct s-TDI to analyze the slow movement of the left ventricular (LV) myocardium in adolescents with systemic arterial hypertension (HT) and to determine whether patients with HT suffer from LV diastolic dysfunction. The study group comprised 69 consecutive patients (48 boys and 21 girls aged 14-17 years [mean, 15.5 ± 1.1 years]) with primary HT, and the control group comprised 48 healthy participants (24 boys and 24 girls aged 14-17 years [mean, 15.8 ± 1.3 years]). Physical examinations, 24-hour arterial blood pressure monitoring, conventional 2-dimensional and Doppler echocardiography, and s-TDIs were performed. Analysis revealed that study group participants were significantly heavier and had greater LV mass indices than controls (P < 0.001). There were no differences between the velocities of E waves (peak early filling of mitral inflow), but the deceleration times of the mitral E waves were significantly shorter whereas the A waves survived longer in the study group than in the control group. The velocities of A waves (peak late filling of mitral inflow) were elevated (P = 0.041), and the E/A wave pattern (E/A = 1.8 ± 0.4) was normal. These results suggest pseudonormalization, a type of LV diastolic dysfunction in adolescents with HT.In the study group, when the sample volume was positioned at the septal or lateral insertion site of the mitral leaflet, the e' wave velocity was significantly depressed whereas the a' wave velocity was elevated, compared to those of the control group (P < 0.001).The e'/a' ratios from the septal and lateral insertion sites were lower, whereas the E/e' ratio from the septal insertion site was significantly higher in the study group, similar to that seen in atrial reversal velocity (P < 0.001).These findings indicate that using sTDI to find and measure diastolic LV failure is valuable when the probe is placed at the septal and lateral mitral valve annuli during examination.Changes in the myocardium appear similar to those seen in adults.

Validation of Standard and New Criteria for the Differential Diagnosis of Narrow QRS Tachycardia in Children and Adolescents

To establish an appropriate treatment strategy and determine if ablation is indicated for patients with narrow QRS complex supraventricular tachycardia (SVT), analysis of a standard 12-lead electrocardiogram (ECG) is required, which can differentiate between the 2 most common mechanisms underlying SVT: atrioventricular nodal reentry tachycardia (AVNRT) and orthodromic atrioventricular reentry tachycardia (OAVRT). Recently, new, highly accurate electrocardiographic criteria for the differential diagnosis of SVT in adults were proposed; however, those criteria have not yet been validated in a pediatric population.All ECGs were recorded during invasive electrophysiology study of pediatric patients (n = 212; age: 13.2 ± 3.5, range: 1-18; girls: 48%). We assessed the diagnostic value of the 2 new and 7 standard criteria for differentiating AVNRT from OAVRT in a pediatric population.Two of the standard criteria were found significantly more often in ECGs from the OAVRT group than from the AVNRT group (retrograde P waves [63% vs 11%, P < 0.001] and ST-segment depression in the II, III, aVF, V1-V6 leads [42% vs 27%; P < 0.05]), whereas 1 standard criterion was found significantly more often in ECGs from the AVNRT group than from the OAVRT group (pseudo r' wave in V1 lead [39% vs 10%, P < 0.001]). The remaining 6 criteria did not reach statistical significance for differentiating SVT, and the accuracy of prediction did not exceed 70%. Based on these results, a multivariable decision rule to evaluate differential diagnosis of SVT was performed.These results indicate that both the standard and new electrocardiographic criteria for discriminating between AVNRT and OAVRT have lower diagnostic values in children and adolescents than in adults. A decision model based on 5 simple clinical and ECG parameters may predict a final diagnosis with better accuracy.

Risk of left atrial appendage thrombus in patients scheduled for ablation for atrial fibrillation: beyond the CHA2DS2VASc score

INTRODUCTION

Atrial fibrillation (AF) increases the risk of thromboembolic events by promoting clot formation in the left atrial appendage (LAA). Transesophageal echocardiography (TEE) is routinely used to exclude the presence of an LAA thrombus before AF ablation. So far, it has not been established what is the optimal combination of noninvasive parameters for thromboembolic risk stratification in this setting and whether patients at very low risk require TEE.

OBJECTIVES

The aim of the study was to assess predisposing factors for an LAA thrombus in patients scheduled for AF ablation and to identify those patients in whom preprocedural TEE is not necessary.

PATIENTS AND METHODS

In consecutive 151 patients (107 men; mean age, 57 ±10 years) the type of AF and renal function were assessed in addition to the CHA2DS2VASc score to improve thromboembolic risk stratification.

RESULTS

An LAA thrombus or dense echo contrast with a strong suspicion of a probable thrombus was detected in 15 patients (10%). Diabetes, age of 65 years or older, persistent AF, and estimated glomerular filtration rate (eGFR) of less than 60 ml/min/1.73 m2 were predictors of the LAA thrombus. A multivariate logistic regression analysis showed that only persistent AF and an eGFR of less than 60 ml/min/1.73 m2 were independent predictors of the LAA thrombus. The receiver operating characteristic curves showed that the greatest area under the curve (0.845) was achieved for the CHA2DS2VASc-AFR (CHA2DS2VASc plus the type of AF and renal function); the difference was not significant. A CHA2DS2VASc-AFR score of 2 or greater or a CHA2DS2VASc score of 1 or greater identified patients with the LAA thrombus with a sensitivity of 100% (and specificity of 54% and 36%, respectively).

CONCLUSIONS

In patients scheduled for AF ablation, an LAA thrombus or dense echo contrast is a relatively common finding despite routine anticoagulant treatment. The addition of AF type and renal function to the CHA2DS2VASc score slightly improves thromboembolic risk stratification and may help identify patients who do not need preprocedural TEE.

Feasibility of implementation of a "simplified, No-X-Ray, no-lead apron, two-catheter approach" for ablation of supraventricular arrhythmias in children and adults

INTRODUCTION

Although the "near-zero-X-Ray" or "No-X-Ray" catheter ablation (CA) approach has been reported for treatment of various arrhythmias, few prospective studies have strictly used "No-X-Ray," simplified 2-catheter approaches for CA in patients with supraventricular tachycardia (SVT). We assessed the feasibility of a minimally invasive, nonfluoroscopic (MINI) CA approach in such patients.

METHODS

Data were obtained from a prospective multicenter CA registry of patients with regular SVTs. After femoral access, 2 catheters were used to create simple, 3D electroanatomic maps and to perform electrophysiologic studies. Medical staff did not use lead aprons after the first 10 MINI CA cases.

RESULTS

A total of 188 patients (age, 45 ± 21 years; 17% <19 years; 55% women) referred for the No-X-Ray approach were included. They were compared to 714 consecutive patients referred for a simplified approach using X-rays (age, 52 ± 18 years; 7% <19 years; 55% women). There were 9 protocol exceptions that necessitated the use of X-rays. Ultimately, 179/188 patients underwent the procedure without fluoroscopy, with an acute success rate of 98%. The procedure times (63 ± 26 vs. 63 ± 29 minutes, P > 0.05), major complications (0% vs. 0%, P > 0.05) and acute (98% vs. 98%, P > 0.05) and long-term (93% vs. 94%, P > 0.05) success rates were similar in the "No-X-Ray" and control groups.

CONCLUSIONS

Implementation of a strict "No-X-Ray, simplified 2-catheter" CA approach is safe and effective in majority of the patients with SVT. This modified approach for SVTs should be prospectively validated in a multicenter study.

Antazoline for rapid termination of atrial fibrillation during ablation of accessory pathways

BACKGROUND AND AIM

To assess safety and efficacy of antazoline for termination of atrial fibrillation (AF) occurring during ablation of accessory pathways (AP).

METHODS

We analyzed electrophysiological mechanism of antazoline (changes in A-A interval) and the percentage of pre-excited QRS complexes before and after antazoline administration. The total dose administered and the time from the start of injection to sinus rhythm restoration were also measured.

RESULTS

Out of consecutive 290 patients with Wolff-Parkinson-White syndrome undergoing radiofrequency (RF) ablation, 12 (4.1%) (4 females, mean age 36 ± 20 years) developed sustained AF which did not stop spontaneously within 10 min, and antazoline in 100 mg repeated boluses was administered. In all 12 patients the drug restored sinus rhythm after a mean of 425 ± 365 s (range 43-1245 s) using a mean cumulative dose of 176 ± 114 mg (range 25-400 mg). The drug slightly prolonged R-R intervals during AF (from 383 ± 106 to 410 ± 70 ms) and reduced the percentage of fully pre-excited QRS complexes (from 35% to 26%). Intracardiac recordings showed gradual increase in A-A intervals, as well as regularization and decreasing fractionation of atrial activity following drug injection (mean A-A interval of 162 ± 30 ms at baseline vs. 226 ± 26 ms shortly before sinus rhythm restoration, p < 0.001). AP was not completely blocked in any patient which enabled continuation of ablation.

CONCLUSIONS

Antazoline safely and rapidly converts AF into sinus rhythm during ablation of AP. The drug does not block AP completely, enabling continuation of ablation. The drug converting AF into more organized atrial activity (atrial flutter/tachycardia) before sinus rhythm resumption.