R. Marazzi

Atrial tachycardias in patients with congenital heart disease: a minimally invasive simplified approach in the use of three-dimensional electroanatomic mapping.

AIMS Atrial tachycardia (AT) is a common complication after repair of congenital heart disease (CHD). This two-centre prospective study evaluated the ability of three-dimensional electroanatomic mapping (EAM) to guide ablation of ATs in this particular population with a minimally invasive simplified approach. METHODS AND RESULTS Thirty-one consecutive patients (mean age 26 ± 17 years) with AT after repair of CHD were treated with a very limited number of intracavitary catheters and a specific setting of the Window of Interest (WoI) for the ablation of post-surgical ATs. A single-intracavitary catheter approach was performed in 22 patients, whereas an overall use of two intracavitary catheters in the other nine patients. Thirty-one patients exhibited 41 ATs. Seventy-six per cent of these were macro-reentrant ATs (MRATs), and 24% were focal ATs (FAT). The mid-diastolic isthmus (MDI) was located in the right atrial free wall (RAFW) in 82.8% of MRATs. Also in FATs, the RAFW was the most common site (77.8%) of the ectopic focus. Fifty-eight per cent of MRATs showed a double-loop reentry, with both loops sharing the same MDI in all cases. In 87% of cases, the abolition of the MRAT was obtained by applying radiofrequency energy to the MDI. Ninety per cent of FATs were successfully ablated. Mean conduction velocity and voltage amplitude had significantly lower values in successfully treated than in unsuccessfully treated MRATs. CONCLUSION Three-dimensional EAM, performed with a minimally invasive simplified approach and by using a specific parameter setting of the WoI, showed to be very effective to guide ablation of ATs in CHD patients.

Left atrial appendage thrombi relate to easily accessible clinical parameters in patients undergoing atrial fibrillation transcatheter ablation: A multicenter study

BACKGROUND Transesophageal echocardiography (TEE) is routinely performed before atrial fibrillation (AF) transcatheter ablation to exclude the presence of left atrial (LA) or LA appendage (LAA) thrombi. The aim of the study is to evaluate if easily accessible clinical parameters may relate to the presence of LA or LAA thrombi to identify patients who could potentially avoid TEE. METHODS AND RESULTS Between January 2012 and September 2014, data from 1539 consecutive patients undergoing TEE, as a work-up before AF transcatheter ablation, in six large volume centers were collected. Baseline clinical features, CHA2DS2-VASc score, transthoracic echocardiography and presence of thrombi at TEE were recorded. Exclusion criteria were valvular, hypertrophic or dilated cardiomyopathy, previous heart surgery or an ejection fraction ≤35%. Mean age was 59.6±10.4years, 1215 (78.9%) were males; 951 (62.9%) presented in sinus rhythm (SR) on admission, 324 (21.1%) had undergone at least one previous ablation and 900 (58.5%) had CHA2DS2-VASc score 0-1. Thrombi were encountered in 12 patients (0.8%). SR at TEE independently related to the absence of thrombi (OR 5.15, 95% CI 1.38-19.02, p=0.015); in addition to this, no patient with a CHA2DS2-VASc score 0-1 and SR on admission presented thrombi at TEE (specificity 100%, p=0.011). CONCLUSION In a selected population of patients referred for AF ablation, LA/LAA thrombi prevalence is low. No patients in SR with CHA2DS2-VASc score 0-1 presented LAA thrombi at TEE, identifying a significant subset of patients who could potentially safely be spared from pre-procedural TEE.

Invasive electrophysiological evaluation and ablation in patients with asymptomatic ventricular pre-excitation persistent at exercise stress test

AIMS In patients with asymptomatic ventricular pre-excitation (VPE) persistent at exercise stress test, this study evaluates the proportion of cases with adverse conduction properties of the atrioventricular accessory pathway (AP) at invasive electrophysiological study and the long-term follow-up after they received treatment according to pre-determined criteria. METHODS AND RESULTS Over 10 years, asymptomatic patients with VPE persistent at exercise stress test referred for invasive electrophysiological evaluation including isoproterenol (IPN) infusion were included. Ablation was planned if they had at least one of the following criteria: (i) shortest pre-excited R-R interval (SPERRI) ≤250 ms and/or (ii) inducible atrioventricular re-entrant tachycardia (AVRT). Cryoablation was electively used in para-hisian and mid-septal APs. Patients non-eligible for ablation received no therapy. Sixty-three patients (45 males; mean age 26 ± 14 years) underwent electrophysiological evaluation: 7 had fasciculo-ventricular fibres and were excluded, whereas 56 had 58 APs. Thirty-one patients (55%) were eligible and underwent successful ablation: 87% had at least the SPERRI ≤ 250 ms and 61% had at least inducible AVRT. In 15 cases (48%) the ablation criteria were met only during IPN infusion. During follow-up (73 ± 33 months), one patient was successfully retreated for resumption of VPE in the ablation group, whereas no event was observed in the group of patients who received no treatment. CONCLUSION In this subset of patients with asymptomatic VPE, invasive electrophysiological evaluation shows fast antegrade conduction over the AP and/or inducible AVRT in about half of the cases. Patients who received no therapy because of a benign electrophysiological profile had an event-free follow-up.

7. Pulmonary Veins: Anatomy and Transcatheter Electrical Isolation7.7 12-Lead Remote ECG Monitoring in Follow-Up of Pulmonary Vein Ablation

Aim to assess usefulness of a 12-lead remote ECG monitoring system (12LRECG) in the follow-up of pts after pulmonary vein ablation (PVA) for atrial fibrillation (AF). Method 5 consecutive pts (4 M, age 52±13 yrs) who underwent PVA for recurrent, drug refractory AF. Four pts with idiopathic AF, one with postsurgical AF for atrial septal defect closure. The 12LRECG is a portable recording device (Aerotel, Heart View 12), transtelephonically downloadable through a call center (Tesan, Vicenza) to a server (Globalcardio), accessible via Internet to authorized personnel. The pts recorded an ECG every day for 40 days after discharge, and in case of palpitations. Results 222 ECG were recorded, all of good quality. AF was documented in 3/5 pts. Pt 1, in a single 12LRECG, with spontaneous sinus rhythm restoration. Pt 2, recurrence of asymptomatic persistent AF preceded by atrial bigeminism from the right superior pulmonary vein. Pt 3, with postsurgical AF, multiple recurrences of paroxysmal AF with few symptoms. Conclusions The 12LRECG is a useful system for the follow-up of pts after PVA, easy to use and with a quality good enough in discriminating arrhythmia morphology.

12-Lead Remote ECG Monitoring in Follow-Up of Pulmonary Vein Ablation

Aim to assess usefulness of a 12-lead remote ECG monitoring system (12LRECG) in the follow-up of pts after pulmonary vein ablation (PVA) for atrial fibrillation (AF). Method 5 consecutive pts (4 M, age 52±13 yrs) who underwent PVA for recurrent, drug refractory AF. Four pts with idiopathic AF, one with postsurgical AF for atrial septal defect closure. The 12LRECG is a portable recording device (Aerotel, Heart View 12), transtelephonically downloadable through a call center (Tesan, Vicenza) to a server (Globalcardio), accessible via Internet to authorized personnel. The pts recorded an ECG every day for 40 days after discharge, and in case of palpitations. Results 222 ECG were recorded, all of good quality. AF was documented in 3/5 pts. Pt 1, in a single 12LRECG, with spontaneous sinus rhythm restoration. Pt 2, recurrence of asymptomatic persistent AF preceded by atrial bigeminism from the right superior pulmonary vein. Pt 3, with postsurgical AF, multiple recurrences of paroxysmal AF with few symptoms. Conclusions The 12LRECG is a useful system for the follow-up of pts after PVA, easy to use and with a quality good enough in discriminating arrhythmia morphology.

7. Pulmonary Veins: Anatomy and Transcatheter Electrical Isolation

Aim to assess usefulness of a 12-lead remote ECG monitoring system (12LRECG) in the follow-up of pts after pulmonary vein ablation (PVA) for atrial fibrillation (AF). Method 5 consecutive pts (4 M, age 52±13 yrs) who underwent PVA for recurrent, drug refractory AF. Four pts with idiopathic AF, one with postsurgical AF for atrial septal defect closure. The 12LRECG is a portable recording device (Aerotel, Heart View 12), transtelephonically downloadable through a call center (Tesan, Vicenza) to a server (Globalcardio), accessible via Internet to authorized personnel. The pts recorded an ECG every day for 40 days after discharge, and in case of palpitations. Results 222 ECG were recorded, all of good quality. AF was documented in 3/5 pts. Pt 1, in a single 12LRECG, with spontaneous sinus rhythm restoration. Pt 2, recurrence of asymptomatic persistent AF preceded by atrial bigeminism from the right superior pulmonary vein. Pt 3, with postsurgical AF, multiple recurrences of paroxysmal AF with few symptoms. Conclusions The 12LRECG is a useful system for the follow-up of pts after PVA, easy to use and with a quality good enough in discriminating arrhythmia morphology.

Complex Supraventricular Tachycardia Ablation: What Is the Role of Alternative Technology?

Radiofrequency catheter ablation is a safe and effective treatment for curing supraventricular tachycardias (SVT), including those related to different forms of atrioventricular (AV) nodal reentry and to the Wolff-Parkinson-White syndrome. Although this treatment is largely considered as a first-line therapy for these tachycardias, under some circumstances the safety and/or the effectiveness of the procedure might be endangered. This review will focus on the difficulties that can be met during SVT catheter ablations, and on the role of special tools and new technologies in improving the success rate and reducing the complications.

Ablation of Atrial Fibrillation: Are We Still “Learning While Burning”?

During the 1990s, the concept of “learning while burning” was introduced and developed by Callans et al. in a series of articles [1–3]. In these papers, the authors expressed the idea that catheter ablation (burning), far from marking the end of pathophysiological investigation, may be viewed as a tool to provide unique and new information (learning) about arrhythmia substrates. Earlier, since with the introduction of catheter ablation electrophysiology had focused more and more on procedural efficacy and case volume, Smith and Cain [4] showed the possible detrimental development from electrophysiology to “electrotechnology,” with loss of research, investigation, and learning-teaching, which has always surrounded the field of cardiac electrophysiology. Recently, the “learning while burning” concept has been revisited and applied [5] to the pathophysiology of atrial fibrillation, where, although the experience of pulmonary vein ablation contributes to the increase of our knowledge day by day, much still remains to be understood of the ultimate mechanism of the arrhythmia. On the other hand, it has been pointed out that trying to elucidate the mechanism of human atrial fibrillation appears as frustrating as being the translator at the Tower of Babel [6], meaning that the pathophysiology of this arrhythmia may present multiple aspects in different clinical and electrophysiological settings, difficult to investigate in humans. In the present paper, we attempt to revisit some aspects of the experience in catheter ablation of atrial fibrillation, trying to point out what we have learnt and what we still have to learn to improve our knowledge and, hopefully, results. For reasons of brevity, only catheter ablation for electrical isolation of the pulmonary veins with an electrophysiological end-point [7] is considered.