Yves Van Belle

Remote magnetic navigated ablation has proven its feasibility in a large group of arrhythmias. Until now only scarce data are available on the use for atrial flutter. In this study we compared remote magnetic navigation (RMN), using non-irrigated and irrigated tip catheters, to manual radiofrequency ablation for ablating typical atrial flutter. The 3 study groups consisted of 17 patients treated with RMN 8-mm tip; 14 patients with RMN irrigated tip; and 24 patients with a manual 8-mm tip. The primary outcome was the number of patients in whom bidirectional isthmus block could be obtained with < or = 15 applications. Secondary end points were the median number of applications needed, the need to switch to a manual irrigated tip catheter, the procedural and fluoroscopy times. There was no significant difference in the primary end point (RMN 8 mm-tip group: 59%, RMN irrigated tip group: 64% and manual group: 83%). The median number of applications needed to obtain block was higher in the RMN groups compared to the manual group. In 5 patients from the RMN 8-mm tip group, 1 in the RMN irrigated tip group and 1 in the manual group, a switch to a manually irrigated tip catheter was performed.There was no difference in fluoroscopy time, but procedural time was significantly longer in the RMN groups compared to the manual group (P= 0.03). The use of magnetic navigation for the ablation of atrial flutter is feasible but not superior to a manual approach. There was no difference concerning the primary end point of acute success within 15 applications. Overall, more applications were needed and procedure times were longer with RMN but RMN with the irrigating tip is promising.

The book is divided into several parts, dealing with central themes: the value of ECG in clinical practice, cardinal clinical presentations, the acute coronary syndromes, dysrhythmias, critical care, toxicology, and a differential diagnosis section. Each part contains chapters around a central question relevant to the main theme (for example: ‘How should the ECG be used in the syncope patient?’, or ‘Can the ECG guide in the treatment of narrow QRS tachycardia?’). The structure of the book therefore easily lends itself as a quick reference. It makes it easy for the reader to find the relevant chapter giving information about the clinical problem he is confronted with, whether it is a symptom, an ECG abnormality, or a general question about electrocardiography. The chapters start with one or more case presentations, accompanied by clear ECG tracings. After the cases, a general review is given of the available ECG literature answering the questions related to the chapter question, to end with the conclusions of the cases presented at the beginning.

The 28 mm cryoballoon catheter is a device used for pulmonary vein isolation (PVI). The aim of this study was to evaluate the extent of the ablation in the antral regions of the left atrium. Eighteen patients with drug refractory, symptomatic, paroxysmal AF were enrolled. A 3D electroanatomic reconstruction of the left atrium was made before and after successful PVI with the 28 mm cryoballoon. Markers were placed at the ostium. Sixteen patients were mapped. Fourteen patients had 4 veins each, and 2 patients had a common ostium of the left sided veins. All separate ostia were isolated in the antral region. The two common ostia showed ostial isolation. There was a significant difference in vein size between the common (29 and 31 mm) and the separate ostia (19 ± 4 mm) (p < 0.01). The performance of an additional segmental ablation if balloon PVI did not eliminate all electrical activity, did not influence the extent of the ablation. The earliest left atrial activation during sinus rhythm was located in the superior septal region before ablation in all patients. After ablation, two patients showed a substantial downward shift towards the middle and inferior septal region respectively (NS). Four patients demonstrated a slight downward shift of the first activation. In cryoballoon PVI, the majority of the veins undergo antral isolation. Veins with a diameter larger than the balloon, are isolated ostially. In individual cases, the left atrial activation sequence appears to be altered after ablation.

A 42‐year‐old man, with a history of hypertrophic cardiomyopathy (HCM), an electrocardiogram pattern of ventricular preexcitation typical for mutations in the PRKAG2 gene, and highly symptomatic paroxysmal drug‐resistant atrial fibrillation (AF), underwent successful circumferential isolation of his pulmonary veins using a 28‐mm double lumen cryoballoon. Because AF was still inducible with programmed stimulation, fractionated signals were targeted in the left atrium with a conventional cryocatheter. Ablation of an endocardial focus with fractionated potentials at the base of the left appendage terminated the episode and rendered AF noninducible. No recurrence of AF was observed during a 10‐month follow‐up period.

Pulmonary vein isolation (PVI) with cryoenergy delivered through a balloon is a new approach in the treatment of atrial fibrillation (AF), but long-term follow-up is lacking. The aim of this study was to provide insight in the success rate and the incidence of recurrences. Patients with symptomatic AF despite anti-arrhythmic drugs (AADs) were treated with cryoballoon PVI. Daily transtelephonic ECG monitoring, 24 h Holter-ECG, and an arrhythmia-focused questionnaire were used to document AF. One hundred and forty-one patients completed a follow-up of 457 +/- 252 days. Before ablation, Holter-ECG showed AF in 45%, including 16% continuous AF throughout the recording. Event recording revealed a median AF burden of 26%. The questionnaire showed a median of weekly AF complaints lasting for hours. All but one patient had successful PVI with a single procedure. After ablation, AF (defined as lasting for more than 30 s) was seen in 11% of Holter-ECGs, with 1% continuous AF. The event recording showed an AF burden of 9%. The median patient reported no more AF-related symptoms. Recurrence during the first 3 months was predictive for later recurrence. A second procedure was performed in 24 patients. The freedom of AF was 59% without AADs after 1,2 procedures. Four right phrenic nerve paralyses occurred, all resolving within 6 months. No PV stenoses were observed. Pulmonary vein isolation with a cryothermal balloon is an effective treatment for paroxysmal AF, resulting in a clinical success rate comparable to studies involving radiofrequency ablation. Temporary right phrenic nerve paralysis is the most important complication.

To assess safety, feasibility and short term outcome of pulmonary vein (PV) isolation in paroxysmal atrial fibrillation (AF) with a cryoballoon. We consecutively treated 57 patients with a double lumen 23 or 28 mm cryoballoon. The acute results, complications and follow-up over the first three months were analysed, using a comprehensive and intensive follow-up period. During 57 procedures, 185 of 220 targeted PV's were successfully isolated using the cryoballoon (84%) (balloon group, 33 patients). In 33 veins (15%) an additional segmental isolation (hybrid group, 24 patients) was necessary with a standard cryocatheter to achieve isolation. The average procedure times were respectively 211 ± 108 and 261 ± 83 minutes (NS), the average fluoroscopy times 52 ± 36 and 66 ± 33 minutes (NS). The number of balloon applications did not differ between both groups: respectively a median 9 (4–18) and 10 (5–17) (NS). We observed four phrenic nerve paralysis after ablation of the right superior PV: two resolved immediately after cessation of the cryoenergy, one recovered after 3 months, one persisted up to 6 months. A daily transtelephonic rhythm recording showed a significant drop in mean AF burden from 24% to 10%, 8% and 5% during the three consecutive months of follow-up (p < 0.01 versus baseline). No differences were observed between the treatment groups. 34 patients (60%) were completely free from AF after a single procedure. Balloon cryoablation of the pulmonary veins with additional segmental isolation if necessary, is a good approach for patients presenting with paroxysmal AF, showing a significant reduction in AF burden after a single procedure. The major complication seems to be phrenic nerve paralysis after ablation of the right superior PV, but this is potentially reversible over several months.