Abstract book RHYTHM 2015

8th EDITION

Palais du Pharo, Marseille, France

May 28-30, 2015 Arrhythmias & Heart Failure: New Insights & Technological Advances Congress directors

Fiorenzo Gaita Franck Halimi Jean-François Leclercq André Pisapia Julien Seitz Jérôme Taieb

Honorary directors Patrick Attuel Claude Barnay

15 CME credit hour(s)

ABSTRACT BOOK www.rhythmcongress.com

Abstracts of the conferences Thursday May 28

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NEW ANTICOAGULANTS NOAC Indications  Jean-Yves LE HEUZEY Georges Pompidou Hospital, René Descartes University, Paris, France

Indications of direct oral anticoagulants in atrial fibrillation After the results of RE-LY, ROCKET AF, ARISTOTLE and ENGAGE AF TIMI 48, it has been clearly demonstrated that direct oral anticoagulants (Dabigatran, Rivaroxaban, Apixaban and Edoxaban) are, at least, non inferior to Warfarin to prevent stroke and systemic embolisms in patients with atrial fibrillation.

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In some cases it has been demonstrated that these drugs could be superior and could decrease mortality as compared to Warfarin. Consequently the European guidelines on the management of atrial fibrillation have considered that the first choice could be one of these direct oral anticoagulants. In some countries there are limitations mainly due to medico-economic considerations.

Oral anticoagulants are indicated in all patients with atrial fibrillation and CHA2DS2-VASc score ≥ 2. For patients with CHA2DS2-VASc 1 it is necessary to discuss the benefit/risk ratio of the anticoagulation. These indications concerns non valvular atrial fibrillation. In valvular atrial fibrillation (patients with mechanic prothetic valves or mitral stenosis) these drugs are contra-indicated and vitamin K antagonists must be used.

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NEW ANTICOAGULANTS NOAC Surveillance follow up  Laurent FAUCHIER Hopital Trousseau, Tours, France

The follow-up of patients with atrial fibrillation (AF) taking anticoagulant therapy should be carefully specified and communicated among the different caretakers of the patient. All anticoagulants have some drug– drug interactions and they may cause serious bleeding. Therapy prescription with this new anticoagulants requires vigilance because AF patient may be fragile, new oral anticoagulants (NOACs) are drugs with potentially severe complications and a significant risk of lawsuits based on medical malpractice exists. Patients should return on a regular basis for on-going review of their treatment, preferably every 3 months. This review may be undertaken by general practitioners with experience in this field and/or by appropriate secondary care physicians. Regular review has to systematically document (1) therapy adherence with appropriate questioning); (2) any thromboembolic event in either the cerebral or systemic circulations; (3) any adverse effects, but particularly (4) bleeding events (which may be occult and revealed by falling haemoglobin levels); (5) co-medications, prescribed or over-the-counter; and (6) blood sampling for renal (and hepatic) function and haemoglobin. Renal function should be assessed more frequently in potentially compromised patients such as the elderly, frail patients, or in those where an intercurring condition may affect renal function, since all NOACs require dose reductions depending on renal function. A dose reduction is needed in patients with kidney disease and a CrCl of 30–50 ml/min or when HAS-BLED ≥3. Minor bleeding is a particular problem in patients treated with any anticoagulant. It is usually dealt with by standard methods to control bleeding, but should not lead promptly to discontinuation or dose adjustment of therapy. Minor bleeding is not necessarily predictive of major bleeding risk. Most minor bleeding is temporary and is best classified as ‘nuisance’ in type. When such bleeding occurs frequently, the patient’s quality of life might be degraded and the specific therapy or dose of medication may require review, but this should be undertaken very carefully to avoid depriving the patient of the highly valuable thromboprophylactic effect of the therapy.

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ABLATION OF ATRIAL FIBRILLATION Contact force technology: closing the missing gaps! ď Ž Franck HALIMI CMC Parly II, Le Chesnay, France

Contact force technology appears to be a major technological innovation for 3D ablation of atrial fibrillation.

It allows creating a true and accurate geometry of the left atrium, delivering efficient radiofrequency ablation pulses and improving catheter ablation security. Contact force reduces total RF delivery energy, X-ray exposure and procedure time and improves patient outcomes. This new feature soon became a new standard for complex RF catheter ablation.

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ABLATION OF ATRIAL FIBRILLATION Comparison of “nearly-missed” versus “on-target” rotor ablation: are movies of the atrial electrical activation sufficient to tell us where to ablate?  Jérôme Kalifa University of Michigan, Ann Arbor, United States

Amongst the electrogram analytical features proposed to unravel the atrial regions that perpetuate atrial fibrillation (AF), complex fractionated atrial electrograms (CFAEs), highest dominant frequency sites (DFmax) and, more recently, phase analysis-enabled rotor mapping have received the largest attention.

Still, the mechanisms by which these approaches modulate AF dynamics and lead to AF termination are unknown.

OBJECTIVE

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Here, we employed advanced optical mapping techniques to examine AF dynamics before and after two distinct electrogram-based ablation strategies: CFAEs and DFmax/rotor ablation.

METHODS

In Langendorff-perfused sheep hearts, AF was maintained by the continuous perfusion of acetylcholine and high-resolution endocardial-epicardial optical movies were recorded from the left atrial free wall (LAFW) and the PLA. Then DFmax/rotor regions (n=7), or CFAE regions harboring the highest wavebreak density (HWD, n=5), were targeted with a 4F ablation catheter (5-15W, 30-60 sec/point). Thereafter, we examined the changes in AF dynamics and whether AF terminated.

RESULTS

DFmax/rotor point ablation resulted in a significant decrease in DFmax values. In 2 animals AF terminated, while in the remainder 5 animals the post-ablation DFmax domain remained in the vicinity of its preablation location. After HWD/CFAEs density ablation, however, DFmax values did not change, AF did not terminate, and post-ablation DFmax domains relocated from the LAFW to the PV-PLA region. In another group of hearts (n=12), we observed that upon a progressive increase in acetylcholine concentration — mimicking the acute electrophysiological changes occurring after ablation — three-dimensional rotors drifted from one atrial region to another along large gradients of myocardial thickness.

CONCLUSIONS

“On-target” DFmax/rotor ablation leads to the annihilation of the fibrillation-driving rotor. This translates into large decreases in AF frequency or AF termination. In contrast, “nearly-missed” HWD/CFAEs ablation spares the fibrillation-driving rotor, and set the stage for rotor drift along large myocardial thickness gradients.

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ABLATION OF ATRIAL FIBRILLATION Atrial tachycardia ablation from the noncoronary aortic cusp ď Ž Robert Pap University of Szeged, Szeged, Hungary

INTRODUCTION

Focal atrial tachycardia (FAT) demonstrating earliest activation in the peri-AV nodal region during right atrial (RA) mapping might require catheter ablation from the left atrium (LA) or the non-coronary aortic cusp (NCC).

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METHODS AND RESULTS

Retrospective analysis of a contemporary, consecutive series of 147 patients undergoing catheter ablation for FAT in our institution was carried out. Earliest activation was recorded in the peri-AV nodal region during RA mapping in 35 (24%) patients. Out of these 7 (20%) patients had successful ablation at the RA septum using either radiofrequency (4 patients) or cryoenergy (3 patients). Nine FATs (26%) were ablated on the LA septum or anteroseptal mitral ring and 19 (54%) patients had successful ablation in the NCC, including one patient with a recurrence after a temporarily successful cryoablation from the RA. The relative frequencies of the three approaches in this series showed significantly more common successful ablation in the NCC (p=0.023). There were two cases of atrioventricular block during RA ablation versus none during NCC ablation.

CONCLUSION

Successful ablation of peri-AV nodal FAT from the NCC is more common, safer and more effective than ablation from RA or LA approaches. Therefore mapping of the NCC should be strongly considered before performing ablation in the His region or transseptal puncture.

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Abstracts of the conferences Friday May 29

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VENTRICULAR ARRHYTHMIAS Ablation within the aortic sinus of valsalva for the treatment of ventricular arrhythmias: role of a surface electrocardiogram algorithm in directing the procedures  Phong Phan Vietnam Heart Institute, Hanoi, Vietnam

OBJECTIVES

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This study investigated the effectiveness and safety of catheter ablation for VT/PVCs originating from the aortic cusps and the role of surface ECG in directing the ablation procedure.

METHODS

This single-center study consisted of 99 consecutive patients with symptomatic ventricular tachycardia and/or premature ventricular contractions (VT/PVCs) with left bundle branch block and inferior axis who underwent radiofrequency (RF) catheter ablation within aortic sinus cusps (ASCs) from April 2010 to Jan 2015. All the procedures were performed with a conventional EP and ablation system. Aortic root angiography was used to define coronary cusps and catheter position. Surface ECGs from the initial 49 VT/PVCs patients with ASC origin were compared with that of 287 consecutive VT/PVCs patients with right ventricular outflow tract (RVOT) origin. Based on the surface ECG criteria, an ECG algorithm was developed to differentiate between the two origins and was used to guide mapping and RF ablation within the ASCs in the next 50 patients.

RESULTS

Of the 99 patients (44 men, mean age 52.6 ± 13.2 years), the sites of origin were the left coronary cusp (LCC) in 60 (60,6%), the right coronary cusp (RCC) in 20 (20.2%), the noncoronary cusp (NCC) in 6 (6,1%), and the junction between the LCC and RCC (L-RCC) in 13 (13.1%) cases. After a mean follow-up of 19.2 ± 10.1 months, 91/99 (91.2%) were free of VT/PVCs without anti-arrhythmic drugs. No severe complications were documented. The ECG criteria which suggest ASC origin included: (1) The R-wave duration index ≥ 50% (calculated by dividing the QRS duration by the longer R wave duration in lead V1 or V2) (sensitivity 49% and specificity 98%). (2) The R/S wave amplitude index ≥ 30% (calculated as the greater value for the R/S wave amplitude ratio in lead V1 or V2) (sensitivity 67% and specificity 94%). (3) QRS transition < V3 (sensitivity 69% and specificity 90%). (4) Presence of small S waves (≤ 40 ms) in leads after transition (sensitivity of 71% and specificity of 90%). Using the ECG algorithm (attached figure) to direct ablation procedure was associated with significant reduction in procedure and fluoroscopy time (69 ± 17 vs 81 ± 25 mins and 11 ± 5 vs 16 ± 8 mins, respectively, p < 0.05) and total time of RF application (263 ± 237 vs 383 ± 237 secs, p < 0.05).

CONCLUSION

Ablation within the aortic sinus of Valsalva is safe and effective for the treatment of ventricular arrhythmias.

Initial differentiation between ASC and RVOT origin of VT/PVCs using surface ECG can significantly reduce procedure and fluoroscopy time and reduce RF ablation time.

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CHANNELOPATHIES CPVT: update on diagnosis and therapy  Christian van der Werf Academic Medical Center, Amsterdam, The Netherlands

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by bidirectional or polymorphic ventricular arrhythmias under conditions of increased sympathetic activity in young patients with structurally normal hearts.1 CPVT can by diagnosed through cardiologic examination, in particular exercise testing, Holter monitoring and adrenaline provocation testing.2 In adults other causes of exercise-induced polymorphic ventricular arrhythmias, in particular ischemic heart disease, need to be excluded. In addition, the diagnosis can be made or confirmed by genetic testing. Mutations in the cardiac ryanodine receptor and calsequestrin genes have been associated with CPVT for almost 15 years. Recently, mutations in several other genes have been associated with CPVT or CPVT phenocopies.3 Patients with CPVT are at risk of developing life-threatening ventricular arrhythmias when untreated.4 This risk is presumably higher in symptomatic patients with a CPVT phenotype than in asymptomatic patients in whom a familial CPVT-causing mutation is identified.5 However, in comparison to other primary arrhythmia syndromes, very little is known about risk stratification in CPVT. ß-blockers are recommended in all patients with a clinical or genetic diagnosis of CPVT,2 but are insufficiently effective in a significant proportion of patients.4 In these patients, the addition of flecainide6,7 and cardiac sympathetic denervation8 are effective adjunctive therapies. The use of implantable-cardioverter defibrillators should be restricted, because ICDs may have harmful effect in CPVT patients.4

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References 1. Van der Werf C, Wilde AAM. Catecholaminergic polymorphic ventricular tachycardia: from bench to bedside. Heart.

2013;99:497–504.

2. Priori SG, Wilde AA, Horie M, Cho Y, Behr ER, Berul C, Blom N, Brugada J, Chiang C-E, Huikuri H, Kannankeril P, Krahn A, Leenhardt A, Moss A, Schwartz PJ, Shimizu W, Tomaselli G, Tracy C. HRS/EHRA/APHRS expert consensus statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes: document endorsed by HRS, EHRA, and APHRS in May 2013 and by ACCF, AHA, PACES, and AEPC in June 2013. Heart Rhythm. 2013;10:1932–1963.

3. Swan H, Amarouch MY, Leinonen J, Marjamaa A, Kucera JP, Laitinen-Forsblom PJ, Lahtinen AM, Palotie A, Kontula K, Toivonen L, Abriel H, Widen E. Gain-of-function mutation of the SCN5A gene causes exercise-induced polymorphic ventricular arrhythmias. Circ Cardiovasc Genet. 2014;7:771–781.

4. Van der Werf C, Zwinderman AH, Wilde AAM. Therapeutic approach for patients with catecholaminergic polymorphic ventricular tachycardia: state of the art and future developments. Europace. 2012;14:175–183.

5. Van der Werf C, Nederend I, Hofman N, van Geloven N, Ebink C, Frohn-Mulder IME, Alings AMW, Bosker HA, Bracke FA, van den Heuvel F, Waalewijn RA, Bikker H, van Tintelen JP, Bhuiyan ZA, van den Berg MP, Wilde AAM. Familial evaluation in catecholaminergic polymorphic ventricular tachycardia: disease penetrance and expression in cardiac ryanodine receptor mutation-carrying relatives. Circ Arrhythm Electrophysiol. 2012;5:748–756.

6. Van der Werf C, Kannankeril PJ, Sacher F, Krahn AD, Viskin S, Leenhardt A, Shimizu W, Sumitomo N, Fish FA, Bhuiyan ZA, Willems AR, van der Veen MJ, Watanabe H, Laborderie J, Haïssaguerre M, Knollmann BC, Wilde AAM. Flecainide therapy reduces exercise-induced ventricular arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia. J Am Coll Cardiol. 2011;57:2244–2254.

7. Watanabe H, van der Werf C, Roses-Noguer F, Adler A, Sumitomo N, Veltmann C, Rosso R, Bhuiyan ZA, Bikker H, Kannankeril PJ, Horie M, Minamino T, Viskin S, Knollmann BC, Till J, Wilde AAM. Effects of flecainide on exerciseinduced ventricular arrhythmias and recurrences in genotype-negative patients with catecholaminergic polymorphic ventricular tachycardia. Heart Rhythm. 2013;10:542–547.

8. Wilde AAM, Bhuiyan ZA, Crotti L, Facchini M, De Ferrari GM, Paul T, Ferrandi C, Koolbergen DR, Odero A, Schwartz PJ. Left cardiac sympathetic denervation for catecholaminergic polymorphic ventricular tachycardia. N Engl J Med. 2008;358:2024–2029.

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FREE PAPERS abstracts Friday May 29

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FREE PAPER Catheter ablation for paroxysmal atrial fibrillation: the vietnam heart institute experience  Pham Tran Linh, Pham Quoc Khanh, Phan Dinh Phong, Le Vo Kien Vietnam Heart Institute, Hanoi, Vietnam

OBJECTIVES

In this study using radiofrequency current and the electroanatomic mapping system CARTO, ablated in 50 patients suffering from drug-refractory atrial fibrillation (paroxysmal AFib).

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BACKGROUND

We treated atrial fibrillation (AFib) with radiofrequency (RF) catheter ablation by creating long linear lesions in the atria. To achieve line continuity, a 3D electroanatomic nonfluoroscopic mapping system was used (CARTO).

METHODS AND RESULTS

In 50 patients with recurrent AF, a catheter incorporating a passive magnetic field sensor was navigated in left atria to construct a 3D activation map. RF energy was delivered to create continuous linear lesions: a long line encircling the pulmonary veins in the left atrium. After RF application, the atria were remapped to validate completeness of the block lines, demonstrated by late activation of the areas circumscribed by the lines. The mean procedure duration was 320,5±30,1minutes , with mean fluoroscopy time of 55,7±7,9 minutes. 02 cases acute complications occurred was tamponate, but success by drain cardiac epicardium. After procedure, 41 patients were in sinus rhythm (81,4%). After a follow-up of 6.0 to 48.0 months (average, 20,0±9,3 months), 43 patients are asymptomatic with Beta blocker (85.3%) and no AFib evidence in holter ECG 24h.

CONCLUSIONS

Recurrent drug-refractory AFib can be treated by RF catheter ablation. Creation of long continuous linear lesions necessary to compartmentalize the atria is facilitated by a nonfluoroscopic electroanatomic mapping system.

Key word: fibrillation – atrial – catheter ablation – paroxysmal – mapping.

References 1.

Anton A.W. Mulder JCB, Maurits C.E.F. Wijffels, Eric F.D. Wever, and Lucas V.A. Boersma (2012 ), “Safety of pulmonary vein isolation and left atrial complex fractionated atrial electrograms ablation for atrial fibrillation with phased radiofrequency energy and multi-electrode catheters”, Europace, 14 (10), pp. 1433 - 1440 2. Calkins H, Kuck KH, Cappato R, et al. (2012), “2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design”, Europace: European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology, 14 (4), pp. 528-606.

3. Chang HY, Lin YJ, Lo LW, et al. (2013), “Sinus node dysfunction in atrial fibrillation patients: the evidence of regional atrial substrate remodelling”, Europace, 15 (2), pp. 205 - 211 4.

Friedman (2002), “Pulmonary Vein Exit-Block During Radio-Frequency Ablation of Paroxysmal Atrial Fibrillation “, Circulation, 105, pp. e124 - e125.

3. Hocini M, Ho SY, Kawara T, et al. (2002 ), “Electrical conduction in canine pulmonary veins. Electrophysiological and anatomical correlation”, Circulation, 105, pp. 2442 - 2448.

4. Oral H, Sharf C, Chugh A, et al. (2003), “Catheter ablation for paroxysmal atrial fibrillation. Segmental pulmonary vein ostial ablation versus left atrial ablation. “, Circulation 108 pp. 2355 - 2360.

5. Pappone C,Giuseppe Oreto FL, Gabriele Vicedomini et al (1999), “Catheter Ablation of Paroxysmal Atrial Fibrillation Using a 3D Mapping System”, Circulation, 100, pp. 1203 - 1208.

6. Yoshida K, Tada H, Ogata K, et al. (2012), “Electrogram organization predicts left atrial reverse remodeling after the restoration of sinus rhythm by catheter ablation in patients with persistent atrial fibrillation”, Heart rhythm : the official journal of the Heart Rhythm Society, 9 (11), pp. 1769-78.

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FREE PAPER Endo-epicardial ablation of ventricular tachycardia in idiopathic dilated cardiomyopathy: a case report ď Ž Soufia Naccache, Franck Halimi, Jean-François Leclercq, Pierre Fiorello CMC Parly II, Le Chesnay, France

Radiofrequency (RF) catheter ablation of ventricular tachycardia (VT) remains a challenging task because of its low success rates. It has become clear that both endocardial and epicardial approaches may be required for an effective treatment of VT, especially in patients with non ischemic cardiomyopathy.

Epicardial ablation is still limited to few high volume centers because of its complexity and potential risks.

This is a case of a 63 year-old man with family history of ventricular arrythmias, folllowed-up for an idiopathic dilated cardiomypathy with low ejection fraction (33%). He was implanted, 8 years ago, with a biventricular defibrillator for ventricular fibrillation. He presented a clinical incessant VT with right bundle-branch block morphology. An endocardial ablation in the postero-lateral wall of the left ventricle was performed. Few days later, he was admitted in our center for recurrence of VT with right bundlebranch block morphology but slightly different from the first one. An epicardial origin was suspected.

The VT stopped spontaneously after pericardial puncture. First, we proceed to an epicardial mapping with Carto 3D system, a substrate-based ablation was performed in the anterior wall of RV. Ventricular stimulation induced the first clinical VT. A postero-basal circuit with slight early activation was defined on the epicardial wall of the LV. Ablation with RF irrigated catheters was accomplished but failed to stop the tachycardia. A complementary mapping of the endocardial myocardium localised an area of early activation with diastolic ventricular potentials in the postero-basal wall of the LV, just opposite the ablated epicardial area. Endocardial RF ablation stopped the tachycardia. Five days later, the patient presented a recurrence of the same clinical VT, so a complementary substrate-based ablation of the endocardial site was performed allowing total extinction of the tachycardia.

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The epicardial ablation is an essential approach for VT, that must be available in an electrophysiology laboratory. In the decision-making strategy, the most important rule is carried out by the type of cardiomyopathy. For idiopathic dilated cardiomyopathy, an endo-epicardial approach should be considered as a first line approach.

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FREE PAPER Effects of primary pci on QTC and QT dispersion in stemi patients  Ouafa Hamza, Salim Benkhedda Cardiologie A2, CHU Mustapha, Alger, Algeria

BACKGROUND

QT dispersion (Qtd) is defined as the difference between the maximal and the minimal values of the QT through the peripheral and precordial leads. It is considered as an arrhythmogenic indice and reflects the inhomogeneity of repolarization.

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AIM

To investigate the effect of revascularization on corrected QT interval (QTc) and Qtd in acute STEMI patients.

METHODS

We conducted a prospective study in which patients presenting with acute STEMI who underwent primary percutaneous coronary intervention (PCI) with successful recanalization were enrolled. QTc and QTd were calculated before, 90 minutes and 24 hours after the procedure. ST resolution was estimated at 90 minutes in the worst lead.

RESULTS

82 patients (70 males, 12 females) with a mean age of 56,9 ± 12,7 years were evaluated. The results showed significant reduction in both Qtc (mean 460.81 ± 26.17 ms vs 439.19 ± 18.43 ms ; p < 0,001) and Qtd (mean 60.68 ± 7.57 ms vs 35.78 ± 10.25 ms; p < 0,001) before and 24 hours after primary PCI while no significant difference was noticed in the Qtc (460.81 ± 26.17 vs 454.39 ± 35.89 ; p = 0.19) and Qtd (60.68 ± 7.57 vs 59.17 ± 7.54; p = 0.20) before and 90 minutes after the procedure.

Preprocedural QTd values were similar in patients with and without ST resolution (67 ± 5.77 vs 62 ± 7.53; p = 0.10). 24h after PPCI QTd decreased only in patients with ST resolution (34.61 ± 9.04 vs 58.5 ± 4.12; p <0.001). Multivariate analysis showed that ST resolution was an independent predictor of QTd after successful recanalization (standardized regression coefficient = -0.684; p = 0.004)

CONCLUSIONS

In addition to a successful opening of the culprit artery, myocardial reperfusion must be achieved to improve electrical stability and reduce repolarization heterogeneity. Recovery of myocardial electrical homogeneity is not immediate and begins 24 hours after revascularization as assessed by QTc and QTd.

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FREE PAPER Mechanism of Torsades de Pointes Elucidated in Human AV Block  Guy Fontaine1, Li G2 1. Hôpital de la Pitié-Salpêtrière, Université Pierre et Marie Curie, Paris, France 2. The First hospital, Xi’an Jiaotong University and College of Medicine, Xi’an, China

OBJECTIVE

Torsades de Pointes (TdP) is the cause of SCD in Long QT syndrome. It is also observed in complete heart block as originally denominated and described by Dessertenne in 1966. Its mechanism was considered as the result of two foci with opposite direction and different rates. This phenomenon has been reproduced in the laboratory. Here we demonstrate by two independent methods that a reentrant phenomenon and not ectopic foci is the mechanism of TdP in patients with complete AV block.

METHOD

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ECG strips were selected from several hours of tape recordings from 1 2 patients with 39x short lasting episodes of TdP TdP (1.9 ± 0.7 seconds). The almost same morphology of the initial TdP beats Torsades can were be identified and classified in different subgroups. In 9 patients’ endocardial recordings (EGM) from regular USCI bipolar catheters positioned at the apex of the right ventricle were synchronously recorded with ECG lead II.

RESULTS

Patient 1: Three subgroups (a-c) of similar initial beats of TdP can be identified Subgroup (a): 3-5 QRs QRS complexes occurred after a long QT interval of 600ms. Subgroup (b): 3-13 QRS complexes occurred with a QT interval of 560ms. Subgroup (c): 4-17 QRS complexes of a different morphology occurred after the same QT interval of 560ms 560ms. One episode of this group leads to ventricular fibrillation needing DC shock. The end of 11 episodes out of 15 is were announced by an increase in the amplitude of the QRS complexes. In four tracings the initial QRS complexesx with the longest QT (660ms) was followed by identical large amplitude PVC but a possible start of TdP is was aborted. Patient 2: A constant coupling of 600ms precedes the Torsade TdP made of 2-6 consecutive almost identical QRS complexes. Final increase of amplitude was observed on 7 out of 13 tracings. Endocardial signals recorded in 5 out of 9 patients showed at the beginning or inside the T wave EGMs with a coupling interval (160-180ms) preceding fragmentation.

DISCUSSION

The classification in subgroups of TdP morphologies indicates that initial bradycardia predetermined identical pathways are present at the beginning of torsade TdP and subsequently follow different routes with a decreased QRS amplitude and increasing fragmentation which can lead to VF. This is in agreement with the (non-tested) mathematical Chaos Theory. The increased amplitude at the end of TdP suggests a better organization and resynchronization of activation from fragmented activation. The intervals of EGM shorter than the effective ventricular refractory period at the beginning of TdP demonstrates a phenomenon of slow conduction. This slow conduction may lead to a large phenomenon of reentry within depressed ventricular myocardium. The EGMs of the two opposite foci would have shown a phenomenon of pseudofusion with successive alternating predominance of each origin of activation without fragmentation.

CONCLUSION

Predetermined variable initial conditions of long QT initiated by bradycardia in complete AV block demonstrate specific preferential pathways of activations durind during the start of short lasting episodes of TdP. Immediate reactivation of endocardial potentials before the end of refractory period suggest that TdP is the result of slow conduction leading to a large unstable reentrant phenomenon.

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FREE PAPER Assessment of sinoatrial node function in patients with persistent and long-standing persistent forms of atrial fibrillation after maze III procedure combined with mitral valve operation ď Ž Aleksei Kulikov Bakoulev Scientific Center for Cardiovascular Surgery, Moscow, Russia

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RESEARCH OBJECTIVE

Assessment of sinoatrial node function after Maze III procedure combined with a mitral valve operation.

METHODS

100 patients were included in the research with persistent and long-standing persistent forms of atrial fibrillation (AF) and need of operative treatment concerning valve disease.

The following preoperative preparation methods were executed to all patients: 1. Electrocardiogram in 12 standard assignments; 2. Two-dimensional echocardiographic 3. Transesophageal echocardiography 4.

Coronary angiography; 5. Computer tomography.

Electric cardioversion in X-ray operating room conditions was performed on all patients. After successful restoration of sinus rhythm, electrophysiological examination (EP) of heart was carried out. Then, on the first or second day after EP study, Maze III procedure combined with a mitral valve operation was performed.

RESULTS

Following the results of Maze III procedure combined with correction of valve disease, disposal of AF was observed in 95% of patients. 46% of patients had stable sinus rhythm to the moment of discharge from the hospital. 24% of patients had atrial rhythm with the maximum heart rate of 80-110 bpm (according to results of 24-hour Holter monitoring). For 25% of patients, it was necessary to implant a pacemaker.

According to results of EP study, 13% of these patients suffered from sick sinus syndrome before operation.

For 9% of the remaining 12% of patients, the indications for pacemaker implantation were atrioventricular nodal rhythm with low heart rate and pauses more than 3 sec long. For 1% of patients the indication was second degree AV block (type 2) and second degree SA block (type 2); for 1% the indication was complete heart block, and for 1% it was atrial rhythm and pauses more than 3 sec long.

13% of patients with an atrial rhythm and normal heart rate developed typical atrial flutter (AFL) in the early postoperative period. For all of them the RF catheter ablation with linear ablation of the right atrial isthmus and creation of isthmus block was effective, and further recurrence of AFL was not observed.

CONCLUSIONS

In the early postoperative period Maze III procedure combined with a mitral valve operation proved to be an effective surgical technique of treatment of persistent and long-standing persistent forms of AF. Only 12% of patients had dysfunction of sinus node work due to iatrogenesis.

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FREE PAPER Mid-term outcome after ablation of atrial fibrillation with second-generation cryoballoon; prediction of recurrence  Alexander Berkowitsch, Ersan Akkaya, Harald Greiss, Nicklaus Deubner, Lars Bodammer, Helge Moellmann, Thomas Neumann, Malte Kuniss Kerckhoff Heart and Thorax Centre, Bad Nauheim, Germany

AIM

Factors predicting outcome after pulmonary vein isolation (PVI) with second-generation cryoballoon (CBA) have not been sufficiently investigated. The aim of this study was to evaluate the impact of several clinical and procedural parameters on outcome after PVI with CBA.

METHODS

Consecutive patients (pts) ablated in our institution with CBA since May 2012 were enrolled in the study.

After a single transseptal access and PV angiography PVI was performed using a 28-mm CBA. Mapping of PV signals before, during, and after each cryo application was performed with a 3F lasso catheter.

The procedural endpoint after PVI was defined as complete elimination of all fragmented signals at the PV antrum with verification of entrance and exit block. The primary endpoint of this study was the first documented recurrence of atrial fibrillation (AF), atrial tachycardia, or atrial flutter (>30 sec.). The impact of variables (gender, age, type of AF, history of AF, hypertension, LVEF, CHA2DS2-VASc-Score, common ostium, left atrial size, intra-procedural cardioversion, nadir temperature, number of applications and application time ) was investigated with univariate Cox regression analysis. All pts were followed prospectively with 7-day Holter ECG recordings every three months.

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RESULTS

The study group consisted of 391 pts with following characteristics: 242 male, paroxysmal AF (PAF) 296(76.2%), median age (IQR)=60(53-66)y, LVEF 62 (59-62)%, history of AF 3.5(1.9-8.2) years, CHA2DS2-VASc-Score 1(1-2), hypertension 262(67.0%) pts, left atrial area (LA area) 19.6 (17.4-22.5) cm². Common ostium was observed in 41 (10.5%) pts. Nadir temperature was -46 (-49/-43)/pat and number of application was 9 (8-10) /pat with application time 220 (180-240) sec. In 53 (13.6%) pts intra-procedural cardioversion was performed to restore sinus rhythm. After a median follow up of 14 (8/21) months the primary endpoint was reached in 50 of 391 pts (12.8%).There was no significant difference in clinical outcome between patients with PAF (258/296 (87.2%) pts free of recurrence) and persistent AF ((83/95) 87.4%), p=.743. Among all parameters analyzed only LA area was found to be predictive of outcome. The optimal cut-off point for LA area was defined at 23 cm². Among 310 pts with LA area < 23 cm² recurrences were noted in 33 (10.6%) vs. 17(21%) in 81 pts with increased LA area ≥23 cm² (p=0.001), HR=2.27 (95% CI: 1.26-4.07)). (Figure 1).

CONCLUSIONS

PVI with CBA in patients with persistent AF seems to be as effective as in patients with PAF. LA area was revealed to be only one predictor of outcome after PVI with CBA in our cohort.

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FIGURE Impact of LA size on outcome after CBA

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FREE PAPER Focal atrial tachycardia originating from the coronary sinus ostium: shall we think about the mitral annulus? ď Ž Soufia Naccache, Franck Halimi, Jean-François Leclercq CMC parly II, Le Chesnay, France

Focal atrial tachycardia (AT) is relatively uncommon cause of supraventricular tachycardia and is difficult to treat medically. Originating from the left or right atrium, catheter ablation has become the treatment of choice of this atrial arrythmia.

This is a case of a 33-year old man with long medical history of incessant atrial tachycardia. He consulted for palpitation and dyspnea. The transthoracic echocardiography showed a dilated cardiomyopathy with low left ventricular ejection fraction (LVEF=25%). The cardiac magnetic resonnance imaging eliminated an underlying cardiomyopathy. Focal atrial tachyacardia arising from the coronary sinus (CS) ostium was suspected on the surface ECG: negative P waves in inferior leads and positive P waves in V1.

Radiofrequency (RF) catheter ablation of atrial arrythmia was adopted since it was responsible of rythmic dilated cardiomyopathy. Left and right atria were mapped showing a foci of origin in the CS ostium.

Ablation in the right atrium failed and the patient was discharged with medical treatment.

Four months later, he was hospitalized in our center for the same symptomatology. A bi-atrial mapping was performed with Carto 3 D system. The earliest arising site was localised to the septal mitral annulus area in the vicinity of the upper segment of the CS ostium. RF ablation in the left atrium with irrigated tips interrupts the atrial tachycardia. The LVEF was normalized within 3 months.

Anatomical proximity of the cardiac structures may make difficult the localisation of the foci of origin of the atrial tachycardia. In case of ablation failure, a changement of anatomical approach should be considered.

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Acknowledgements

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