G.B. Chierchia

Pulmonary vein ostium shape and orientation as possible predictors of occlusion in patients with drug-refractory paroxysmal atrial fibrillation undergoing cryoballoon ablation

AIMS No specific data are available on the influence of pulmonary vein (PV) anatomy and shape on cryoballoon ablation (CA) catheter efficacy in delivering cryothermal energy and, consequently, in obtaining PV isolation. METHODS AND RESULTS Among a larger series of patients (68) with drug-refractory paroxysmal atrial fibrillation who underwent CA in our department, 52 patients were included in our study. All of them had a multislice cardiac computed tomography (MSCT) before the procedure. We retrospectively evaluated their MSCT scans focusing our attention on PV ovality and orientation in the frontal plane. A fair inverse association was documented between the ovality index of the left PVs and the degree of occlusion (r=-0.486 and P<0.003 for the LSPV and r=-0.360 and P=0.033 for the LIPV), whereas no association was found between the ovality index of the right PVs and the degree of occlusion (r=-0.283 and P=0.083 for the RSPV and r=0.235 and P=0.093 for RIPV). Nevertheless, a strong inverse association was found between the orientation of the PV ostia and the degree of occlusion in each vein (r=-0.804 and P<0.001 for the LSPV, r=-0.415 and P=0.013 for LIPV, r=-0.798 and P<0.001 for the RSPV, and r=-0.867 and P<0.001 for RIPV). CONCLUSION Pulmonary vein ostium shape and orientation evaluated by MSCT proved to be useful in predicting the degree of occlusion obtained during CA.

Feasibility, safety, and outcome of a challenging transseptal puncture facilitated by radiofrequency energy delivery: a prospective single-centre study.

AIMS Although it has been shown that a transseptal (TS) puncture in the electrophysiology laboratory is associated with a high success and a low complication rate, this procedure remains challenging particularly in difficult septum anatomies (aneurismal septum and thick septum) and during repeat TS catheterization. Radiofrequency (RF) electrocautery current delivery through the TS needle has been shown to facilitate the TS puncture. The aim of this study was to verify prospectively the feasibility, safety, and outcome of RF energy delivery associated with the standard TS technique in patients undergoing a challenging TS puncture. METHODS AND RESULTS Over a 14-month period, 162 consecutive patients underwent left atrial (LA) arrhythmia ablation in our centre. Among them, we enrolled 18 patients who failed LA access after two TS puncture attempts. In these patients, an RF delivery through TS (RF-TS) needle approach was used to reach the LA. All 18 patients had a successful RF-TS at the first attempt. A transoesophageal echocardiography (TEE) guidance and fluoroscopy views were used in all patients. No acute complications were reported. There have been no clinical sequelae after 10 +/- 4 months of follow-up following the RF-TS approach. Challenging TS punctures were more frequent in repeat LA catheterization when compared with the first LA catheterization, respectively, in 35% (13 of 37) and 4% (5 of 125) of the patients. CONCLUSION Radiofrequency electrocautery delivery associated with the standard TS approach is a safe and reproducible technique to reach the left atrium, using the TEE guidance. This technique is helpful during repeat TS catheterization and in the presence of anatomical atrial septum abnormalities.

Added value of transoesophageal echocardiography during transseptal puncture performed by inexperienced operators

AIMS Transseptal puncture (TP) appears to be safe in experienced hands; however, it can be associated with life-threatening complications. The aim of our study was to demonstrate the added value of routine use of transoesophageal echocardiography (TEE) for the correct positioning of the transseptal system in the fossa ovalis, thus potentially preventing complications during fluoroscopy-guided TP performed by inexperienced operators. METHODS AND RESULTS Two hundred and five patients undergoing pulmonary vein isolation procedure (PVI) for drug-resistant paroxysmal or persistent atrial fibrillation were prospectively included. When the operator (initially blinded to TEE) assumed that the transseptal system was in a correct position according to fluoroscopical landmarks, the latter was then checked with TEE unblinding the physician. If necessary, further refinement of the catheter position was performed. Refinement >10 mm, or in case of catheter pointing directly at the aortic root or posterior wall were considered as major repositioning. Thirty-four patients required major repositioning. Regression analysis revealed age (P: 0.0001, Wald: 12.9, 95% confidence interval: 1.04-1.16), left atrial diameter (P: 0.01, Wald: 6.6, 95% confidence interval: 1.04-1.34), previous PVI (P: 0.01, Wald: 6.3, 95% confidence interval: 1.31-8.76), and atrial septal thickness (P: 0.03, Wald: 4.5, 95% confidence interval: 1.05-3.4) as independent predictors of major revision with TEE. CONCLUSION Routine 2D TEE in addition to traditional fluoroscopic TP appears to be very useful to guide the TP assembly in a correct puncture position and thus, to avoid TP-related complications. However, further randomized prospective comparative studies are necessary to support these suggestions.

Complications of atrial fibrillation ablation: when prevention is better than cure.

As atrial fibrillation ablation is becoming increasingly popular in many cardiac electrophysiological laboratories around the world, preventing, avoiding, or treating procedure-related complications is of utmost importance. In our review of the literature regarding this issue, we addressed in detail all the potential collateral and undesired effects associated to this intervention.

First experience of monitoring with cardiac event recorder electrocardiography Omron system in childhood population for sporadic, potentially arrhythmia-related symptoms

AIMS To document symptomatic episodes of palpitations with traditional methods such as24 h Holter monitoring (HM) or loop recorders remains a big challenge in clinical practice. Clinical trials with patient-activated electrocardiography (ECG) recorders show increased diagnostic yield in such patients. However, studies in the paediatric population are limited. We want to present a first experience with an event-recording system Omron HeartScan in children with symptomatic palpitations. METHODS AND RESULTS Thirty paediatric patients (age 4-16 years) were followed with the Omron at our centre. All patients had a normal echocardiogram, a normal baseline 12-lead ECG and a normal 24 h HM. Indications with regard to monitoring were palpitations (n = 30). Two of them also had episodes of pre-syncope. The average of palpitation episodes in the past 3 months was 13.2 ± 8.3. The mean age of the study population was 9.7 ± 2.3 years [17 males (56.7 %)]. In all patients (n = 30) a diagnostic event could be recorded with the studied system. Four patients were diagnosed with supraventricular tachycardia (SVT) and underwent catheter ablation. The remaining patients (n = 26; 87%) were diagnosed with sinus tachycardia. Two patients with SVT additionally had episodes of pre-syncope. None of the patients could be diagnosed with previous 24 h HM. CONCLUSION This event recorder has a high diagnostic yield in the childhood population. The children enjoyed the ease of using the system under daily-life conditions. In this study the system was able to record a diagnostic event in all patients with palpitations.

Diagnosis-to-ablation time as a predictor of success: early choice for pulmonary vein isolation and long-term outcome in atrial fibrillation: results from the Middelheim-PVI Registry

Aims The aim of the study is to define long-term outcome of pulmonary vein isolation (PVI) in atrial fibrillation (AF) and to determine whether time window between AF diagnosis and PVI affects outcome. Methods and results Consecutive AF patients undergoing PVI (2006-14) were followed for 5 years. Primary outcome was clinical success, defined as freedom of documented AF without anti-arrhythmic drugs respecting a 1-month blanking period. A 1000 patients were included (age 60 ± 10 years, CHA2DS2-VASc score 1 ± 1). The cohort was divided in four quartiles (Q) according to the diagnosis-to-ablation time (DAT): Q1 DAT 0-11 months (N = 244), Q2 DAT 12-≤33 months (N = 254), Q3 DAT 34-≤70 months (N = 252) and Q4 DAT 71-360 months (N = 250). Mean follow-up was 44.3±21.0 months. At 5 years, clinical success was achieved in 45.2 ± 2.0% of patients. Independent predictors of clinical success were AF type (HR = 0.61; 95%CI 0.50-0.74; P < 0.0001), left atrial size (HR = 1.03; 95%CI 1.02-1.05; P < 0.0001), DAT (HR = 1.00; 95%CI 1.00-1.00; P = 0.001), ablation technique (P = 0.012), and year of ablation (HR = 0.93; 95%CI 0.86-1.00; P = 0.045) in multivariable-adjusted analysis. The highest clinical success was achieved when PVI was performed within the first year, and gradually declined with increasing DAT: 55.9 ± 4.6% for Q1, 46.9 ± 4.0% for Q2, 45.5 ± 3.6% for Q3, and 35.5 ± 3.6% for Q4 (P < 0.001). Conclusion Long-term success rate of PVI is 45.2 ± 2.0%. Shorter diagnosis-to-ablation times are associated with better clinical success. Our data advocate for early PVI following diagnosis of AF.

Only a boost away from re-entry

Looking closely, the dual atrioventricular nodal (AVN) physiology is evident with a ‘jump’ into the slow pathway (SP) and a crossing over phenomenon, before retrograde conduction over the fast pathway (FP) initiating typical AVN reentrant tachycardia (AVNRT) (Fig. 1). A new electrophysiological study (EPS) was performed, but attempts to induce the tachycardia were again unsuccessful, even under isoproterenol. However, after delivering a lowwatt (20W), low-temperature (40°) radiofrequency application into the SP region, sustained AVNRT started within 30 s. Successful SP ablation was achieved at higher power/ temperature (50W/55°). This case underlines the importance of the atrial lead in patients with Brugada syndrome, in view of the higher risk of developing atrial arrhythmias including AVNRT [1]. In our case, the atrial lead did not contribute to arrhythmia discrimination by the device, but had its value in the posthoc analysis, which prompted the repeated EPS. Misclassification resulted from the high rate (ventricular fibrillation [VF] zone), but would still have occurred in the ventricular tachycardia (VT) zone (‘dual-chamber detection’), as it cannot differentiate AVNRT from VT with 1:1 retrograde conduction (Biotronik, SMART). To avoid further inappropriate shocks, a strategy might be dual-zone programming with a VF zone at even higher rate limits, longer detection counters, and anti-tachycardia pacing (ATP) during capacitator charging (possibility to stop AVNRT before shock

Anaesthetic considerations for hybrid atrial fibrillation surgery

Editor—Hybrid atrial fibrillation surgery consists of simultaneous epicardial and endocardial ablation of the beating heart by thoracoscopy and percutaneous femoral approaches, respectively, without cardiopulmonary bypass support. The epicardial ablation may be bilateral or unilateral. A joint effort of different teams is required: cardiologist, cardiac surgeon, anaesthetists, respiratory therapists, and nurses. The cardiopulmonary bypass team is on standby. Anaesthetic considerations for hybrid surgery involve control of perioperative haemodynamic and respiratory stability and postoperative pain control. We review our institutional approach here for the benefit of new programmes. Hypotension, attributable to the loss of atrial kick, carbon dioxide insufflation in the thoracic, mediastinal, and pericardial cavities, and the effect of surgery during ablation on pulmonary venous return, is frequently observed after the onset of singlelung ventilation. Carbon dioxide insufflation pressures should be limited to avoid a tamponade effect. Judicious titration of