CardioneuROablation for reflex syncope: efficacy and effects on autonoMic cArdiac regulatioN. The Roman 1 study

Purpose

To assess the effects of CNA on syncope recurrences in patients with VVS

Methods

The Roman 1 study was a prospective, randomized, investigator-initiated trial comparing CNA versus optimal standard therapy in patients with asystolic VVS. Patients were included if they had documented symptomatic cardioinhibitory or mixted spontaneous VVS (at least 3 seconds of asystole), frequent and/or severe symptoms (at least one syncope or 3 presyncopal events during preceding 12 months or very severe syncope in the past, leading to injury) and positive atropine test (>30% increase in sinus rate). CNA was performed using RF ablation of the ganlionated plexi from the left and right atrium. Follow-up lasted 2 years. Primary endpoint was time to first syncope recurrence. One of secondary endpoints were changes in quality of life (QoL) assessed using dedicated questionnaire The Impact of Syncope on Quality-of-Life Questionnaire University of Calgary.

Results

48 patients (17 males, mean age 38±10, 24 – CNA group, 24 – control group) entered the study. Baseline demographic and clinical characteristics were similar in both groups. The primary end-point – syncope recurrence, occurred in 2 (8%) patients from the CNA group versus 12 (50%) controls (p=0.00037, see Kaplan-Meier curve). QoL significantly improved in the CNA group (30±10 vs 10±7 points, p=0.0001) whereas remained stable in controls (31±10 vs 30±10 points, p=0.5501).

Conclusion(s)

This is the first randomized study documenting efficacy of CNA in patients with asystolic VVS. Larger studies are needed to confirm these findings.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Centre of Postgraduate Medical Education

Reversed U-curve mapping and ablation of the left pulmonic cusp for treatment of the left ventricular summit arrhythmias

Funding Acknowledgements

Type of funding sources: None.

Introduction

Catheter ablation (CA) of the left ventricular summit (LVS) arrhythmias can be challenging. Close proximity of the left pulmonic cusp (LPC) offers a unique opportunity for targeting the LVS region. Whether LPC can serve as a vantage point for mapping and CA of LVS premature ventricular contractions (PVC) and ventricular tachycardia (VT) has not yet been systematically evaluated.

Methods

This is a retrospective analysis of consecutive patients who underwent CA of LVS PVC/VT and concomitant mapping and/or ablation within the LPC using reversed U-curve technique. PVC/VT activation precocity was determined and CA (unipolar, sequential unipolar and/or bipolar ablation) was performed involving LPC when necessary.

Results

A total number of 18 patients (age 59±15 years, 10 females) were included in this study. LPC mapping using reversed U-curve was successful in 17 (94%) patients. An earliest PVC/VT activation was recorded in LPC in 7 (39%). No early activation in the LPC was found in 5 (28%) patients. Selective LPC ablation (24W, 206s) led to acute suppression with late VT recurrence in one patient, whereas LPC served as an additional ablation target for sequential CA (37±4W, 416±252s) in 11 (61%) patients. 6 (33%) patients required combined sequential unipolar and bipolar CA (37±8W, 690±248s) between LPC and adjacent LVOT and this approach led to PVC/VT elimination in 5 patients. There were no procedure-related complications. During follow up 4 (22%) patients required redo ablation. Ultimately clinical success was achieved in 14 (78%) patients.

Conclusions

LPC mapping of LVS PVC/VT using reversed U-curve is safe and can be helpful for determination of LVS arrhythmia site of origin. While LPC ablation alone is rarely successful in eliminating LVS arrhythmias, it can serve as an anatomical vantage point for additional ablation of LVS PVC/VT as a part of sequential unipolar or bipolar CA.

Optimal catheter-tissue contact value for ablation of ventricular arrythmias originating from the left ventricular papillary muscles

Funding Acknowledgements

Type of funding sources: None.

Background

Good catheter-tissue contact is mandatory to create effective ablation lesions. The minimal contact force (CF) value for successful ablation of arrhythmias originating from the left ventricle (LV) was reported at the 8-10 g level, however, optimal CF values for ablation of arrhythmias arising from papillary muscles (PM) are not known.

Purpose

To determine optimal CF value for ablation of arrhythmias from LV PM.

Methods

Twenty-four consecutive patients (mean age 57,9 ± 11,9 years, 16 males) who from May 2017 to June 2020 underwent ablation of premature ventricular complexes (PVC) originating from LV PM were included. The primary endpoints were an acute procedural success (total elimination of PVC) and long-term success (median 27 months). Ablation was performed with the use of the CARTO electro-anatomical system and intracardiac echocardiography (ICE).

Results

Acute success – complete abolition of PVC, was obtained in 23 (96%) patients. The fluoroscopy time was 3,9 ± 3,5 min and the procedure duration was 114,8 ± 38 min. The mean number of applications was 8,74 ± 6,78 and the mean application time - 518,5 ± 437,25 sec. The mean CF during successful ablations was 3,1 ± 1,5 g, with 3 ± 1,1 g and 3,18 ± 1,8 g for anterolateral and posteromedial PM, respectively (p= 0,809975). The mean CF during one unsuccessful ablation was 3 g. At control Holter ECG, the mean PVC burden in all patients was reduced from 28,36 ± 14,48 % to 2,42 ± 2 %: in the anterolateral PM group from 18 ± 8 % to 2,6 ± 2 % (p= 0,005415) and in the posteromedial PM group - from 34,8 ± 13,7 % to 1,7 ± 1,3 % (p= 0,012694). During long-term follow-up (median 27, IQR 17-34) there was one recurrence among 23 patients who had acutely successful procedures.

Conclusion

The values of CF for successful ablation of PVC originating from LV PM are lower than those for ablation in other parts of LV. The values slightly exceeding 3 g seem to be sufficient to achieve ablation success.

Right anterior ganglionated plexus ablation for the treatment of vagally-mediated atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) is a cornerstone for catheter ablation of atrial fibrillation (AF), however, exact mechanisms of PVI efficacy remain debatable. PVI is an invasive left-atrial procedure which may be associated with complications. It has been postulated that in patients with increased vagal tone AF can be treated by attenuation of parasympathetic drive to the heart using cardioneuroablation (CNA) by means of radiofrequency (RF) ablation of the ganglionated plexi, however, data in literature are lacking.

Objectives

To examine the mid-term efficacy of RF-CNA targeting the right anterior ganglionated plexus (RAGP) in the management of AF using right-atrial (RA) approach only.

Methods

We included consecutive 12 male patients (age 55±11) with vagally-mediated AF (decelaration capacity (DC) >7 ms, mean 11,2±3,7ms) who underwent RF-CNA of RAGP. RAGP was targeted anatomically at the septal area below superior vena cava (SVC) from RA only. The aim was to achieve ≥30% heart rate acceleration (HRA). The follow up consisted of regular visits combined with ECG conducted every 3 months and 24h or 7-day Holter ECG.

Results

The RF time was 126±61 sec, power - 34±7W and procedure time - 44±18 min. The ≥30% HRA was achieved in 7 (58%) patients (pre-RF vs post-RF: 58±7 bpm vs 80±9 bpm, p=0,0000013). There were no complications during procedures. The follow up lasted 11±6 months. All patients reported significant symptom improvement post-CNA. AF-free survival was significantly higher in patients with ≥30% HRA during RF-CNA (≥30% HRA vs <30% HRA, 60% vs 14%, log rank p=0,0203) Conclusions: Right atrial RF-CNA of RAGP can be effective in patients with vagally-mediated AF. Larger prospective studies are needed to confirm these preliminary findings.

Bipolar catheter ablation for highly refractory cardiac arrhythmia - does the success rate depend on arrhythmia origin?

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Despite technological progress, some arrhythmias are still refractory to standard unipolar ablation. They include arrhythmias arising from left ventricular (LV) summit, cardiac crux or epicardium. Bipolar ablation may be useful in some cases, however, data on efficacy of this approach in various arrhythmia localisatons are scarse.

Purpose

Aim of the study was to assess efficacy of bipolar catheter ablation in patients with cardiac arrhythmias refractory to standard ablation approach.

Methods

Observational, single-center study was conducted over 30-month period. Twenty-six consecutive patients (male=18, aged = 54.26 ± 16.4) who were referred for bipolar ablation were included. All patients had a history of previously failed unipolar ablation procedures. Bipolar ablations were performed using dedicated RF generator and electroanatomic mapping system.

Results

Twenty-seven procedures in 26 patients with a mean of 2.52 ± 0.83 previously failed unipolar ablations were included in the final analysis. There were 4 ablations of accessory pathways (3 postero-septal and 1 left free wall) with acute success rate of 100%, 11 procedures of ventricular arrhythmias originating from crux of the heart with acute success rate of 73% and 12 from left ventricular summit (LV summit) with acute success rate of 50%. Mid-term success rate (median follow-up of 182 days) was 100%, 63% and 50% respectively. There was one major complication (not related to RF bipolar ablation): cardiac tamponade due to aortic cusp rupture requiring urgent cardiac surgery procedure.

Conclusions

Bipolar ablation is a promising method of catheter ablation for refractory arrhythmias. The highest success rate was observed in ablation for difficult pathways, followed by ventricular arrhythmias originating from cardiac crux and LV summit.

Catheter ablation of atrial fibrillation without pulmonary vein isolation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) is a cornerstone for catheter ablation (CA) of atrial fibrillation (AF), however, long-term efficacy of PVI is frequently below expectations. PVI is invasive, expensive and may be associated with devastating complications. It has been postulated that vagally-mediated AF can be treated by attenuation of parasympathetic drive to the heart using cardioneuroablation by means of radiofrequency CA (RFCA) of the right anterior ganglionated plexus (RAGP), however, data in literature and guidelines are lacking.

Purpose

To examine the efficacy of RFCA targeting RAGP without PVI in management of vagal AF.

Methods

We included consecutive 9 male patients with vagal AF who underwent RFCA of RAGP without PVI. RAGP was targeted anatomically from the right atrium (RA) at the postero-septal area below superior vena cava (SVC) and from the left atrium (LA) if needed. The aim was to achieve >30% increase in heart rate (HR) . The follow up consisted of regular visits and Holter ECG conducted every 3 months.

Results

A total number of 9 patients (age 52 ± 13) with vagally-mediated AF underwent RFCA of RAGP (mean RAGP RF time 147 ± 85, max power 34 ± 8W). The mean procedure time was 60 ± 29min. HR increase >30% was achieved in 8 (89%) patients (pre-RF vs post-RF: 58 ± 8bpm vs 87 ± 12bpm, p = 0.00002) . Transseptal  to reach RAGP also from the LA was needed in 2 (22%) patients. There were no major complications during the procedures. The follow up lasted 6 ± 2 months. Antiarrhythmic drugs were discontinued in 8 (89%) patients. There was 1 (11%) AF recurrence in the patient in whom targeted HR acceleration during RFCA was not achieved. B-blockers were administered in  6 (67%) patients due to increased HR and such treatment was well tolerated by all.

Conclusions

Catheter ablation of RAGP without performing PVI is feasible and can be effective in majority of patients with vagally-mediated AF. Increased HR after such cardioneuroablation can be well controlled using b-blockers and is usually associated with mild symptoms. The role of cardioneuroablation for treatment of vagally-mediated AF needs to be determined in prospective trials. Abstract Figure. Cardioneuroablation in vagal AF

Ultrasound-guided extra-cardiac vagal stimulation during cardioneuroablationa-a pilot feasibility study

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

N/A

Background. Cardioneuroablation (CNA) is a promising method for treatment of vagally-induced vasovagal syncope or functional atrio-ventricular block. Extra-cardiac vagal stimulation (ECVS) from the internal jugular vein is used during CNA to document asystolic response prior to CNA and lack of effects of vagal stimulation on heart rate after CNA.  The recommended technique is placing the pacing catheter under fluoroscopy in the internal right and left jugular vein up to the level of the upper wisdom tooth. However, this technique has several limitations such as increased radiation exposure, unselective cranial nerves stimulation and lack of visualization of vagal nerve. Ultrasound-guided (USG) approach may be an interesting option because it allows visualization of the vagal nerve and enables selective  stimulation under visual control.

Purpose. To assess the utility of USG-guided ECVS during CNA procedures.

Methods. The study group consisted of 6 patients (4 males, mean age 35 ± 12-year-old) underwent CNA.  Firstly, electrode for ECVS was introduced under fluoroscopy into the right and left jugular veins up to the level of the upper wisdom tooth and ECVS was performed. Next, the USG-guided examinations were performed in supine position with head extension. The probe was placed in the transverse plane above the medial edge of the sternocleidomastoid muscle. The course of vagal nerve was identified and place for imaging in the close neighborhood of the jugular vein was chosen. ECVS was performed when the electrode was in good contact with the vein wall and was in the vicinity of the vagal nerve. In both approaches vagal response (asystole and atrio-ventricular block) during ECVS was assessed before and after CNA.

Results. In all patients ECVS was performed from both right and left jugular vein. Localization of vagal nerve using USG was possible in all patients and took less than one minute (see Figure). The effects of ECVS were identical using standard fluoroscopic and USG-guided approach.

Conclusions. USG-guided ECVS during CNA is easy, results are comparable with standard fluoroscopic approach and is probably associated with less fluoroscopy. Since this non-invasive method is the only one which enables vagal nerve visualization, it should become a preferred approach when using ECVS during CNA procedures. Abstract Figure. A electrode position for USG-guided ECVS

Anterior position of dispersive patch for esophageal protection during atrial fibrillation ablation. A pilot feasibility study

Funding Acknowledgements

Type of funding sources: None.

Introduction

Ablation for atrial fibrillation (AF) carries a significant risk of esophageal injury. Current methods of esophageal protection are invasive, expensive and their cost-effectiveness can be questioned. Standard placement of dispersive patch (DP) at patient’s back exposes esophagus to radio-frequency (RF) current-mediated thermal injury and such complications as esophageal wall ulceration, peri-esophageal injury or life-threatening atrio-esophageal fistula. Redirecting RF current by DP repositioning to anterior chest can theoretically protect oesophagus from thermal injury, however, such an approach has not yet been investigated.

Aim

To determine feasibility of anterior DP position for treatment of AF using RF catheter ablation (RFCA)-based system.

Methods

We retrospectively analysed consecutive patients undergoing  RFCA-based pulmonary vein isolation (PVI) using multi-electrode PVAC catheter with DP located either in anterior or traditional-posterior position. Two additional patients underwent point-by-point RFCA and mapping of PV ostia with impedance measurements during RFCA performed using anterior and posterior DP positioning.

Results

62 patients (25 females, age 60 ± 12 years) underwent PVI using PVAC: 40 patients in posterior and 22 in anterior DP group. There were no major complications during procedures. There was no significant difference in AF recurrence rate between anterior and posterior DP groups during one-year follow up (log rank p = 0.065). In two additional consecutive patients (1 female, age 74 ± 2 years) undergoing point-by-point RFCA a total number of 30 measurements around PV ostia were performed. There was a significant difference between impedance values in anterior vs posterior DP positions (134 ± 7 Ω vs 122 ± 8 Ω, p = 0.0004).

Conclusions

Anterior position of dispersive electrode for PV isolation using RFCA-based systems is safe, feasible, atraumatic and is not associated with any additional cost. Apart from redirecting RF current away from the esophagus, anterior dispersive patch placement is associated with higher impedance values which can act as an additional protection. Possible prevention of esophageal complications using anterior dispersive patch positioning needs to be determined in prospective studies. Abstract Figure. AF-free survival and impedance

Left atrial function after successful catheter ablation for paroxysmal atrial fibrillation: cryoablation versus radiofrequency techniques

Funding Acknowledgements

Type of funding sources: None.

Purpose

It has been suggested that cryoballoon (CB) ablation for paroxysmal atrial fibrillation (PAF) may lead to more extensive left atrial (LA) injury than radiofrequency (RF) ablation, however, results are conflicting. We sought to address this issue using modern echocardiographic techniques.

Methods

We performed transthoracic echocardiography in 90 patients (66% males, mean age 57 ± 10 years) successfully treated  with RF (51%) or CB (49%) ablation for PAF before and 6 months after the procedure. Peak longitudinal LA strain (LAS) and strain rate (LASR) during the reservoir (r), conduit (cd) and contraction (ct) phases were measured during sinus rhythm by speckle tracking. The LA diameter and volume (LAV) index - using biplane area-length method divided by the body surface area were also calculated.

Results

The LA diameter decreased (38.1 ± 4.0 vs 37.2 ± 3.8 mm, p = 0.004), the LAV index did not change (33.5 ± 11.9 vs 34.4 ± 8.9 mL/m², p = 0.272) at 6 months in the whole study group. The LASRr and LASRcd increased, whereas there were no changes in remaining LA function parameters in either ablation strategy (table). The CB subgroup did not differ in LA function parameters comparing to RF subgroup at six months after procedure (table).

Conclusion

CB and RF ablation did not differentially affect the LA function. Successful ablation for PAF resulted in improvement of  rate of deformation during reservoir and conduit LA cycle and stable contractile LA function.

LA function parameters RF N = 46 (51%) CB N = 44 (49%) 6 months RF vs CB Parameter Baseline 6 months p Baseline 6 months p p* Global LASr [%] 27.7 ± 6.35 27.9 ± 6.0 0.833 27.9 ± 7.2 27.0 ± 6.4 0.370 0.539 Global LAScd [%] -14.6 ± 4.1 -14.8 ± 4.6 0.761 -15.3 ± 5.3 -14.1 ± 3.2 0.080 0.399 Global LASct [%] -13.0 ± 4.84 -13.0 ± 3.20 1.00 -12.6 ± 3.81 -12.9 ± 4.18 0.629 0.897 Global LASRr [sˉ¹] 1.18 ± 0.22 1.27 ± 0.26 0.046 1.07 ± 0.27 1.18 ± 0.30 0.041 0.141 Global LASRcd [sˉ¹] -1.11 ± 0.33 -1.25 ± 0.35 0.013 -1.07 ± 0.31 -1.16 ± 0.30 0.044 0.214 Global LASRct [sˉ¹] -1.46 ± 0.40 -1.50 ± 0.31 0.500 -1.42 ± 0.51 -1.39 ± 0.42 0.742 0.187 *p value corrected for baseline values

673Bipolar radiofrequency ablation supported by non-ionic catheter irrigation

Introduction

Bipolar radiofrequency catheter ablation (Bi-RFCA) or irrigation of ablation catheter (AC) using non-ionic coolant, such as dextrose-5 in water (D5W), are novel ways to improve lesion formation in case of arrhythmia refractoriness. Combination of these two methods has not yet been described.

Puprose

To determine feasibility and effectiveness of Bi-RFCA additionally supported by non-ionic catheter irrigation for treatment of refractory premature ventricular complexes (PVC) or ventricular tachycardia (VT).

Methods

Consecutive patients after failed extensive Bi-RFCA or D5W-irrigated ablation for symptomatic PVCs or non-sustained VT (nsVT) underwent Bi-RFCA supported with D5W coolant.

Results

We ultimately enrolled 2 patients (2 males, age 64 ± 12 years) after failed extensive ablations for the left ventricular summit PVCs and nsVT to undergo Bi-RFCA supported with D5W irrigation of both AC and intracardiac return electrode (IRE). Previous pharmacological antiarrhythmic treatment consisting of at least one drug and catheter ablation failed in both patients. Bi-RFCA was delivered between earliest activation sites located in the left/right aortic commissure and the left pulmonic cusp (Figure). Efforts were made to achieve safe distance from coronary arteries, AC, and IRE.  Bipolar RFCA (35 ± 7W power, 8 ± 4 applications, 199 ± 166s RF time)  led to acute elimination of PVCs in both patients. Baseline impedance oscillated around 250Ω and initial 50-70Ω impedance drop was observed during first 20s of bipolar applications, followed by impedance rise up to 350-450Ω. No steam pop occurred and  there were no complications during procedures. All antiarrhythmic drugs were discontinued. Follow-up lasted 8 ± 2 months, there was no nsVT recurrence and 90,4% PVC burden reduction was achieved: from 30000 to 3100 PVC/day in patient #1 and from 39000 to 3500 PVC/day in patient #2. Both patients remained symptom-free.

Conclusion

Bi-RFCA can be additionally supported using non-ionic D5W coolant. Such approach is feasible and can be safe and effective. More data on impedance imbalance during D5W-supported bipolar RF applications is warranted.

Abstract Figure. Fluoroscopic view and 12-lead ECG

P1127Occurrence, management and outcomes of iatrogenic aortic dissections as a complication of catheter ablation. A multicenter study

Background

Data on occurrence, management and outcomes of iatrogenic aortic dissections (IAD) as a complication of catheter ablation (CA) do not exist.

Purpose

To evaluate multicenter data on occurrence, management and outcomes of IAD as a complication of CA.

Methods

Data on occurrence, management and outcomes of documented vascular dissections from 10 centers were evaluated.

Results

IADs occurred in 7 patients (2 females, age 63 ± 8 years). Indications for CA were frequent premature ventricular complexes (PVC)/ventricular tachycardia (VT) in 6 patients (86%) and left-sided accessory pathway in the remaining one (14%). Hypertension was most frequent comorbidity (4 pts, 57%).  All IADs occurred during retrograde advancement of ablation catheter. In the vast majority of patients creation of IAD during catheter advancement was not associated with any symptoms (6 pts, 86%). IAD was initially detected using trans-luminal angiogram in 5 (71%) and further confirmed using computed tomography (CT) (5 pts, 71%), conventional angiography (2 pts, 28%) and ultrasound (2 pts, 28%). One IAD was detected during CT scan performed for other indication after CA. There was one IAD-related death and IAD was evaluated post-mortem. Follow-up lasted 10 ± 19 months. Four patients were treated conservatively, one patient underwent descending aorta stenting and one femoral artery stenting.

Conclusions

IAD during CA is a rare but can be devastating. Early recognition can be difficult. Conservative management of IAD is an option of treatment.

P1096Cardioneuroablation changes the type of vaso-vagal response in patients with asystolic reflex syncope

Funding Acknowledgements

Centre of Postgraduate Medical Education No. 501-1-10-14-19

Background. Cardioneuroablation (CNA) - ablation of ganglionated plexi (GP) to eliminate or reduce parasympathetic overactivity, has been recently proposed as a new therapeutic method in patients with vaso-vagal syncope (VVS) due to cardioinhibitory or mixed mechanism.

Purpose. To assess the impact of CNA on the type of VV response during tilt testing (TT).

Methods. The study group consisted of the first 20 patients (7 males, mean age 38 ± 9 – year – old) enrolled in the ongoing prospective Roman study (NCT 03903744). All patients had a history of ECG documented syncope due to asystole and confirmed asystolic form of VVS at baseline TT. CNA was performed using electroanatomical system Carto 3 and radiofrequency applications delivered in the right and left atrium at the right anterior GP and right inferior GP sites. The second TT was performed three months later. Resting heart rate (HR) and heart rate variability parameter (SDDN) were also assessed.

Results. At baseline TT, nineteen patients had cardioinhibitory syncope (asystole ranging from 3 to 60 s)  (sinus node arrest – 17 patients, A-V block – 2 patients) and 1 had mixed form of VVS (asystole lasting 3 s preceded by hypotension). During three-month follow-up no syncopal episodes were noted. At the 3-month TT, 6 (30 %) patients had no syncope whereas the remaining 13 (65 %)  had syncope – twelve (60 %) due to vasodepressor mechanism and only one (5 %) due to asystole - as before CNA. One patient did not have TT because of pregnancy. Mean resting HR after CNA was significantly faster and SDNN significantly lower than before the procedure (82 ± 9 vs 69 ± 11 beats/min, p = 0.0004 and 74 ± 22 vs 143 ± 40 ms, p = 0.00003, respectively) and these changes were was similar in those who fainted during second TT and those who did not (82 ± 11 vs 81 ± 4 beats/min, p = NS and (75 ± 2 vs 77 ± 18 ms, p = NS, respectively).

Conclusions. CNA profoundly affects the type of VV reaction causing normalization of the response to tilting or changing cardiodepression to vasodepression. These effects are also depicted by changes in HR and heart rate variability. Elimination of TT-induced reflex asystole may prevent clinical recurrences of syncope during short-term follow-up. These findings encourage to conduct further studies involving CNA since this method appears to be effective and obviates the need for pacemaker implantation in young people with reflex asystolic syncope.

133Bipolar ablation of refractory ventricular arrhythmias originating from the close proximity of His bundle

Introduction

Biophysics of bipolar radiofrequency catheter ablation (Bi-RFCA) suggest more condensed and selective lesion formation when compared to conventional-unipolar approach. Whether more selective Bi-RFCA can result in safe and effective ablation of arrhythmic substrates in close proximity of His bundle has not been investigated so far.

Purpose

To determine feasibility and effectiveness of Bi-RFCA in His bundle area.

Methods

Consecutive patients after failed unipolar ablation for symptomatic premature ventricular complexes (PVC) or ventricular tachycardia (VT) originating from the vincity of His bundle underwent Bi-RFCA.

Results

We ultimately enrolled 8 patients (2 females, age 60 ± 15 years) to undergo Bi-RFCA of PVC/VT. Previous pharmacological treatment consisting of at least one antiarrhythmic drug and conventional catheter ablation failed in all. Bi-RFCA using open-irrigated and non-irrigated ablation catheters (AC) was delivered from two earliest PVC/VT activation sites located in the vincity of His bundle (Figure, panels A-B). A total number of 93 bipolar applications were delivered (mean bipolar RF time 508 ± 565s, mean power 35 ± 13W, mean impedance 163 ± 18Ω). Transient conduction disturbances occurred in 2 patients and were associated with mechanical compression of conduction system. No persistent conduction disturbances occurred. Bipolar RFCA led to acute elimination of PVC/VT in 6 (75%) patients. Follow up lasted 11 ± 5 months: two patients underwent repeat procedure using dual-irrigated Bi-RFCA, there was no VT recurrence and 72% PVC burden reduction was achieved (16200 ± 11600 pre-ablation vs 4500 ± 6200 post-ablation PVC/day, p = 0,035) (Figure, panel C).

Conclusion

Bi-RFCA performed in proximity of His bundle can be safe and effective in majority of patients.

Abstract Figure. Bipolar ablation of parahisian PVC/VT

P318 Left atrial dysfunction assessed by echocardiography in relation to left atrial fibrosis in patients undergoing ablation for atrial fibrillation

PURPOSE

Left atrial (LA) fibrosis is the hallmark of LA remodeling in atrial fibrillation (AF), alters LA function and may predict poor catheter ablation (CA) outcome. LA fibrosis may be assessed invasively using electroanatomical mapping (EAM) during electrophysiological study.

The aim was to assess LA function parameters in relation to degree of LA fibrosis derived from EAM in patients with AF.

METHODS

Patients (pts) n = 39 (79% males, mean age 56+/-10) with non-valvular AF were studied with TTE and TEE before first CA during sinus rhythm. LA strain (LAS) and strain rate (LASR) were analyzed in reservoir (r), conduit (cd) and contractile (ct) phases. The velocities of mitral A, E" and A" were measured with Doppler. E/E" and LA stiffness index - the ratio of E/E" to LASr were assessed. LA appendage flow velocity (LAAv) was measured in TEE. LA volume using biplane area-length method was calculated.

The EAM of LA was build using Carto System before CA. 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 sites of fibrosis. LA parameters were compared between mild (LAPA <10%) moderate (LAPA 10-40%) and extensive degree of LA fibrosis (LAPA >40%) (table).

RESULTS

The mean LA volume was 35 ± 11 mL/m². The LAPA ranged from 2 to 78 % of LA surface. Reduced LA function was observed in the LAPA >40% group. Extensive LAPA altered mainly LA compliance parameters. Traditional LA systolic function parameters did not differ in relation to degree of LAPA.

CONCLUSION

LA compliance is mostly affected by LA fibrosis, thus LA diastolic parameters may be useful in the noninvasive assessment of LA fibrosis. Whether these parameters should be a part of the proper selection of candidates for CA requires further studies.

LA function parameters LA parameters Group 1 LAPA <10% n = 13 Group 2 LAPA >10% <40% n = 13 Group 3 LAPA >40% n = 13 P-value Group 1 + 2 vs 3 Mitral A 0.55 ± 0.10 0.55 ± 0.24 0.73 ± 0.32 0.077 A" 9.19 ± 1.74 7.85 ± 1.43 7.92 ± 2.40 0.376 LASr 31.48 ± 4.52 26.48 ± 8.79 19.63 ± 6.76 <0.001 LAScd 17.30 ± 3.05 15.44 ± 6.93 10.91 ± 4.04 0.003 LASct 14.18 ± 5.36 11.05 ± 3.67 8.72 ± 4.78 0.024 LASRr 1.22 ± 0.19 1.24 ± 0.21 0.92 ± 0.20 <0.001 LASRct -1.71 ± 0.46 -1.37 ± 0.34 -1.04 ± 0.33 <0.001 LA stiffness 0.20 ± 0.07 0.34 ± 0.17 0.63 ± 0.29 <0.001 LAAv 0.83 ± 0.18 0.55 ± 0.17 0.60 ± 0.16 0.178

Conflict of interest policies and disclosure requirements among European Society of Cardiology National Cardiovascular Journals

Disclosure of potential conflicts of interest (COI) is used by biomedical journals to guarantee credibility and transparency of the scientific process. COI disclosure, however, is not systematically nor consistently dealt with by journals. Recent joint editorial efforts paved the way towards the implementation of uniform vehicles for COI disclosure. This paper provides a comprehensive editorial perspective on classical COI-related issues. New insights into current COI policies and practices among European Society of Cardiology national cardiovascular journals, as derived from a cross-sectional survey using a standardised questionnaire, are discussed.

Premature ventricular complex-induced chronic cough and cough syncope

The present case study reports a case of chronic cough and cough syncope associated with frequent premature ventricular complexes (PVCs). Careful analysis of cough-related symptoms and ECG monitoring led to the suspicion of PVC-induced cough. A coincidence between PVCs and episodes of cough was also documented by a portable multichannel recorder. Moreover, Doppler echocardiography revealed a PVC-induced transient increase in the pulmonary artery blood flow. After exclusion of other possible aetiologies, complete relief of chronic cough and cough syncope was achieved by radiofrequency ablation of the arrhythmogenic focus located in the right ventricular outflow tract. Premature ventricular complexes should be considered as a cause of chronic cough and cough syncope and an interdisciplinary cooperation can lead to successful diagnosis and treatment of this condition.

Efficacy and safety of dofetilide in the prevention of symptomatic episodes of paroxysmal supraventricular tachycardia: a 6-month double-blind comparison with propafenone and placebo

BACKGROUND

Existing drug therapies for paroxysmal supraventricular tachycardia (PSVT) have potentially serious adverse effects. Dofetilide, a pure class III antiarrhythmic agent, may offer an effective and safe alternative for treating PSVT. This study compared the efficacy and safety of dofetilide with that of propafenone and placebo in the prevention of PSVT.

METHODS

This multicenter, randomized, placebo-controlled, parallel-group study compared the effectiveness of oral dofetilide 500 microg given twice daily with that of propafenone 150 mg given 3 times a day and placebo in preventing the recurrence of PSVT in 122 symptomatic patients. Episodes of PSVT were documented by symptom diaries and Hertcard (Hertford Medical, Hertfordshire, UK) event recorders.

RESULTS

After 6 months of treatment, patients taking dofetilide, propafenone, and placebo had a 50%, 54%, and 6% probability, respectively, of remaining free of episodes of PSVT (P <.001 for both dofetilide and propafenone vs placebo). Both dofetilide and propafenone also decreased the frequency of episodes of PSVT; the median numbers of episodes in the dofetilide- and propafenone-treated groups were 1 and 0.5, respectively, compared with 5 in the placebo-treated group. Dofetilide was well tolerated; no proarrhythmia occurred. Three patients taking propafenone had serious treatment-related adverse effects that required drug discontinuation.

CONCLUSIONS

Dofetilide and propafenone were equally effective in preventing the recurrence of or decreasing the frequency of PSVT.

Extrasystolic beats affect transmural electrical dispersion during programmed electrical stimulation

BACKGROUND

Experimental studies suggest that the electrocardiographic Tpeak-Tend (TpTe) interval reflects transmural dispersion of repolarization (TDR). The genesis and role of the TpTe interval in a clinical setting have not been established. This study aimed to assess the clinical usefulness of the TpTe interval as an index of TDR and a pro-arrhythmic marker.

MATERIALS AND METHODS

Endocardial monophasic action potential (MAP) duration and electrocardiographic QTp, QTe and TpTe intervals were assessed in 13 patients undergoing an electrophysiological study. Surface electrocardiograms were recorded during right ventricular pacing (Basic Cycle Length = 600 ms) before and after single extrastimuli.

RESULTS

Ventricular arrhythmia was induced in six patients. During ventricular pacing, MAP duration and QTp intervals shortened in response to extrastimuli applied at progressively shorter coupling intervals. In contrast, QTe intervals increased in response to premature stimulation and QTe dispersion increased at short coupling intervals. During sinus rhythm, the TpTe interval was greater in the inducible group in leads V3-V4. Premature stimulation increased the duration of TpTe intervals, suggesting an increase in TDR. The maximum TpTe interval was greater in the inducible than in the noninducible group, both during baseline ventricular drive pacing (163 +/- 22 vs. 130 +/- 27 ms, respectively, P < 0.03) and after application of shortly coupled extrastimuli (263 +/- 66 vs. 200 +/- 47 ms, respectively, P < 0.05).

CONCLUSIONS

The TpTe interval of surface ECG is likely to represent TDR. TDR is increased by premature ventricular stimulation and the magnitude of the maximum TpTe interval (i.e. maximum TDR) during ventricular pacing is greater in patients with inducible arrhythmias.

Use of spectral turbulence analysis for the identification of patients at high risk for ventricular fibrillation and sudden death in patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy carries an increased risk of sudden death. The aim of the present study was to assess the predictive value of the signal-averaged ECG, analysed in the time domain and using a new method, spectral turbulence analysis, for the identification of high-risk patients. Two-hundred and forty-six patients with hypertrophic cardiomyopathy were studied. During a mean follow-up of 68 +/- 17 months, 17 patients died suddenly. Patients with sudden death (SD) and/or a history of ventricular fibrillation (VF; n = 25) were compared to patients without SD/VF (n = 221) and to patients without any recognised risk factors for SD (n = 82). There were no differences in mean values of the time domain or spectral turbulence parameters analysed between patients in the SD/VF group and the patients without SD/VF or in the low-risk group. It is concluded that the clinical usefulness of the signal-averaged ECG, analysed in the time domain or as spectral turbulence analysis, is limited in identifying high-risk patients with hypertrophic cardiomyopathy.

Wavelet decomposition analysis of the signal averaged electrocardiogram used for risk stratification of patients with hypertrophic cardiomyopathy

AIMS

To study the predictive value of wavelet decomposition, as demonstrated by the signal-averaged ECG, in order to identify patients with hypertrophic cardiomyopathy at increased risk for malignant ventricular arrhythmias or sudden death.

METHODS AND RESULTS

Two hundred and forty-six patients with hypertrophic cardiomyopathy were studied. During a mean follow-up of 68 +/- 17 months 32 patients died, of whom 17 died suddenly. Patients with sudden death, together with eight patients with a history of ventricular fibrillation (sudden death/ventricular fibrillation group) were analysed and compared to the other 221 patients as well as to a subgroup of 82 patients without a history of syncope, ventricular arrhythmias on a long-term ECG recording or a family history of sudden death. There were no differences in mean values of the four wavelet decomposition parameters among patients in the sudden death/ ventricular fibrillation group, those without sudden death/ ventricular fibrillation or patients in the low risk group. There were, however, significant differences between patients dying non-suddenly and patients being alive at the end of follow-up. Eighty-seven patients (35%) demonstrated evidence of non-sustained ventricular tachycardia on a long-term ECG. Analysis of wavelet decomposition resulted in abnormal findings in these patients more often than in those without ventricular arrhythmias.

CONCLUSION

The usefulness of wavelet decomposition analysis in predicting sudden death or ventricular fibrillation is limited in patients with hypertrophic cardiomyopathy. It may, however, play a role in identifying patients at risk of dying non-suddenly and of patients with non-sustained ventricular tachycardia.

The incidence of asymptomatic paroxysmal atrial fibrillation in patients treated with propranolol or propafenone

Anti-arrhythmic therapy for paroxysmal atrial fibrillation leads to complete symptomatic relief in a number of patients. The elimination of symptoms may be associated either with a complete elimination of arrhythmia or with a conversion of symptomatic atrial fibrillation into asymptomatic episodes of arrhythmia. The aim of the study was to evaluate the occurrence of asymptomatic paroxysmal atrial fibrillation in 52 patients treated with propafenone (35 drug trials) or propranolol (34 drug trials) by means of ambulatory ECG Holter monitoring. Propafenone was clinically effective (complete relief of symptoms) in 26 (74%) patients. However, in 7 cases (27%) asymptomatic episodes of arrhythmia were still recorded when awake. In patients treated with propranolol clinical symptoms were absent in 18 (53%). However, in 4 (22%) patients attacks of paroxysmal atrial fibrillation were present. The mechanism of drug-induced conversion of symptomatic episodes of atrial fibrillation into asymptomatic spells of arrhythmia was a marked shortening in duration of episodes in 7 patients (from 2215 +/- 3843 s to 16 +/- 10 s, N.S.) or by a significant slowing of ventricular response during atrial fibrillation in 4 patients (from 125 +/- 27 to 84 +/- 8 beats/min, P = 0.05). In conclusion, in a significant proportion of patients with symptomatic paroxysmal atrial fibrillation asymptomatic episodes of arrhythmia may occur while on anti-arrhythmic drug therapy. Some of these patients, particularly those with other risk factors for stroke such as advanced age or the presence of organic heart disease, may require anti-coagulant therapy or change in anti-arrhythmic treatment, and can be selected on the basis of ambulatory ECG monitoring.