Search

Background: In the 123-study, we prospectively assessed, in a randomized fashion, the minimal cryoballoon application time necessary to achieve pulmonary vein (PV) isolation (PVI) in patients with paroxysmal atrial fibrillation (AF) with the aim to reduce complications by shortening the application duration. The first results of this study demonstrated that shortened cryoballoon applications (

Aims Adenosine administration after pulmonary vein (PV) isolation using radiofrequency, laser, and cryoablation can cause acute recovery of conduction to the PVs and predict atrial fibrillation (AF) recurrence. This study evaluates whether ablation of dormant potentials post-adenosine administration following second-generation cryoballoon (CB-2G) ablation may improve the success rate for AF. Methods and results In 45 of 90 patients after a waiting period of 30 min, a bolus 15-21 mg of adenosine was administered followed by rapid saline flush. The response was assessed for each PV using a circular octapolar catheter. If needed, further ablation using a cryoballoon and/or cryocatheter was performed until no reconduction was observed after repeat adenosine administration. The remaining 45 patients did not receive adenosine after the procedure. Acute PV isolation was achieved in 352 of 358 PVs (98.3%) of 86 of 90 patients (95.6%) using CB-2G. The adenosine group showed dormant reconduction in 5 of 45 patients (11%), 8 of 179 PVs (4.5%), including 1 left superior pulmonary vein, 3 left inferior pulmonary vein, 1 right superior pulmonary vein, and 3 right inferior pulmonary vein. The success rate for adenosine and without adenosine group was 84 and 79%, respectively, after a mean follow-up of 397 +/- 47 and 349 +/- 66 days, without any AF recurrence in patients in whom adenosine-induced dormant conduction was ablated. Conclusion Adenosine testing after second-generation cryoballoon ablation study showed that reablation of initially isolated PVs increases the clinical success rate for AF.

Aims Unlike in the Wolff–Parkinson–White syndrome, there has been no systematic study on the role of the pre-excitation pattern in predicting the ablation site in patients with atriofascicular (AF) pathways. We assessed in a large cohort the value of the 12-lead electrocardiogram (ECG) during antidromic tachycardia (ADT) to predict the site of ablation. Methods and results Forty-five patients were studied, 23 males (51%), mean age of 27 ± 12 years with 46 AF pathways and 48 ADT using the AF pathway for A–V conduction. Inclusion required induction of a sustained ADT and successful ablation. Ablation site was assessed during LAO 45° projection and clockwise classified as hours in posteroseptal, posterolateral, lateral, anterolateral, and anteroseptal tricuspid annulus as follows: 05:00–07:00, >07:00–08:00, >08:00–09:00, >09:00–11:00, and >11:00–13:00 o'clock. The QRS axis was assessed during ADT and classified as normal (>+15°), horizontal (+15° to −30°), and superior (

Adenosine administration after pulmonary vein (PV) isolation using radiofrequency and cryoablation can cause acute recovery of conduction to the PVs and predicts atrial fibrillation (AF) recurrence. This study evaluated whether adenosine testing after second-generation balloon devices (cryothermal and laser) could reveal dormant PV reconduction and recurrence rate of AF. Out of total 60 patients, 20 patients underwent PV isolation using laser balloon and for the remaining patients, the cryoballoon was used. Following PVI, waiting period of 30 min was obtained. Thereafter, a bolus 15-21 mg of adenosine was injected followed by rapid saline flush. The subsequent response was assessed for each vein using an in situ lasso catheter. Further ablation (if needed) using laser balloon and cryocatheter respectively was done, until no reconduction occurred after repeat adenosine. Acute PV isolation was achieved in all 80 PVs of 20 patients (100 %) using laser device and in 151 PVs (96.2 %) of 38 patients (95 %) using cryoballoon. However, in seven patients (35 %), 11 PVs (13.7 %) (4 LSPV, 2 LIPV, 4 RSPV, and 1 RIPV) showed dormant PV potentials after adenosine administration in laser group. Cryoballoon group showed dormant reconduction in four patients (10 %), four PVs (5 %) [one LSPV, one LIPV, and two RIPV]. The follow-up of 337 +/- 92.4 days for cryoballoon and 267 +/- 76.9 days for laser balloon group demonstrated similar success rates (85 %). Adenosine testing after PV isolation using second-generation balloon based energy devices (laser and cryothermal) reveals dormant conduction in initially isolated PVs with similar long-term success rate.

BACKGROUND Idiopathic atrial fibrillation (AF) refers to a clinically lacking cardiovascular or pulmonary disease generating the pathophysiologic substrate for the arrhythmia. However, because idiopathic AF is associated with an increased event rate, it could be a harbinger of as-yet undetected underlying heart disease. OBJECTIVE The purpose of this study was to determine the prevalence of coronary artery disease (CAD) in patients diagnosed with idiopathic paroxysmal AF. METHODS Of the 3243 patients who underwent cardiac computed tomographic angiography (CTA) in our center between January 2008 and March 2011, we identified a total of 115 consecutive idiopathic paroxysmal AF patients who underwent CTA before electrophysiologic ablation. Patients were compared with 275 age-, sex-, and PROCAM risk score-matched healthy controls in permanent sinus rhythm. All patients were free of hypertension, diabetes, congestive heart failure, previous known coronary artery and peripheral vascular disease, previous stroke, thyroid, pulmonary, and renal disease, and structural abnormalities on echocardiography. RESULTS Controls more often showed a family history of CAD (38% vs 15%, P

Purpose The frequent occurrence of ventricular tachycardia can create a serious problem in patients with an implantable cardioverter defibrillator. We assessed the long-term efficacy of catheter-based substrate modification using the voltage mapping technique of infarct-related ventricular tachycardia and recurrent device therapy. Methods The study population consisted of 27 consecutive patients (age 68 +/- 8 years, 25 men, mean left ventricular ejection fraction 31 +/- 9%) with an old myocardial infarction and multiple and/or hemodynamically not tolerated ventricular tachycardia necessitating repeated device therapy. A total of 31 substrate modification procedures were performed using the three-dimensional electroanatomical mapping system. Patients were followed up for a median of 23.5 (interquartile range 6.5-53.2) months before and 37.8 (interquartile range 11.7-71.8) months after ablation. Antiarrhythmic drugs were not changed after the procedure, and were stopped 6 to 9 months after the procedure in patients who did not show ventricular tachycardia recurrence. Results Median ventricular tachycardias were 1.6 (interquartile range 0.7-6.7) per month before and 0.2 (interquartile range 0.00-1.3) per month after ablation (P = 0.006). Nine ventricular fibrillation episodes were registered in seven patients before and two after ablation (P = 0.025). Median antitachycardia pacing decreased from 1.6 (interquartile range 0.01-5.5) per month before to 0.18 (interquartile range 0.00-1.6) per month after ablation (P = 0.069). Median number of shocks decreased from 0.19 (interquartile range 0.04-0.81) per month before to 0.00 (interquartile range 0.00-0.09) per month after ablation (P = 0.001). One patient had a transient ischemic attack during the procedure, and another developed pericarditis. Nine patients died during follow-up, eight patients due to heart failure and one patient during valve surgery. Conclusion Catheter-based substrate modification using voltage mapping results in a long-lasting reduction of cardioverter defibrillator therapy in patients with multiple and/or hemodynamically not tolerated infarct-related ventricular tachyarrhythmia.

Sudden cardiac death (SCD) remains the leading cause of death in industrialized world. The majority of SCD is caused by ventricular fibrillation associated with structural and/or ischemic heart disease. Ventricular fibrillation represents the final common pathway for SCD and, thus, is an attractive target for ablation. According to class I recommendation level of evidence A, an implantable cardioverter defibrillator (ICD) should be implanted for such patients [1]. Other than programmed electrical extrastimulus technique, isoproterenol infusion is commonly used in invasive cardiac electrophysiology labs for arrhythmia induction. We hereby report a rare case of transient coronary spasm during isoproterenol infusion for ventricular tachycardia induction testing.disorder is very rare and usually appears in middle aged patients. It is a clinical diagnosis. It could cause a variety of symptoms, especially, acute appendicitis and unidentified lesion in the right iliac fossa. According to the reasons, it could be just a curiosity without any relevancy or the sign of a malignant lesion with bad prognostic factors. The histopathological findings prove the origin.

Gal et al. [1] reported the results of the 50 patients treated for atrial fibrillation (AF) using the endoscopic laser balloon ablation system (EAS) in the Netherlands, who were recruited for the study between December 2011 and December 2013. The second-generation EAS uses a compliant balloon to improve balloon/tissue contact, which improves the energy delivery to create consistent lesions and, ultimately, to achieve durable pulmonary vein (PV) isolation. The study’s mean procedure and fluoroscopy time were 171 and 36 min, respectively. Temporary phrenic nerve palsy was observed during a single procedure. After a median follow-up of 17.3 (12.9–19.5) months, 58 % of the patients remained free of AF, after a single EAS PV isolation without the use of antiarrhythmic drugs. Between November 2012 and July 2013, 24 patients underwent PV isolation using the second-generation EAS at the Maastricht University Medical Center. Oesophageal temperature monitoring was adopted for all patients to avoid undesired excessive oesophageal thermal injury. Acute PV isolation was achieved in all 80 PVs of 20 patients (100 %). The mean procedure and fluoroscopy time were comparable with that of Gal et al., 180 ± 44 and 25 ± 10 min, respectively. In all of these patients except four, a bolus of 15–21 mg of adenosine was injected followed by a rapid saline flush, 30 min after the last energy application [2]. Restoration of electrical conduction by adenosine-mediated hyperpolarisation occurred in 11 PVs (13.7 %) in seven patients (35 %), namely the left superior PV in four, the left inferior PV in two, the right superior PV in four, and the right inferior PV in one. Additional EAS-guided ablation was performed in these veins achieving complete isolation. We did not observe any oesophageal temperature rise above 39 °C for any of the patients. The complication rate was relatively low with one case of spontaneously resolving phrenic nerve palsy, one patient with transient ST-segment elevation conservatively managed by sublingual nitroglycerin, and one groin haematoma. After a 3-month blanking period, patients received a 24–48 h Holter monitor every 3 months for 1 year to assess AF recurrence. Previously, we have reported that of these patients, 85 % were free of AF without antiarrhythmic drugs, after a median follow-up of 267 ± 76.9 days [3]. Currently, after a follow-up of 18.9 ± 2.3 months, the success rate is 81 % [4]. The higher medium-term AF-free survival after EAS-PV isolation at Maastricht may be partly explained by a potentially shorter learning curve due to prior experience with a similar balloon-based ablation system, i.e. cryoballoon. In addition, the elimination of adenosine-mediated PV reconnections may have contributed to the clinical benefit, although the incremental value remains to be resolved. In addition, elimination adenosine-mediated PV reconnections may have increased the overall success rate [5, 6].

Cryoablation of Ventricular Tachycardia. Introduction: Transvenous cryoablation has proven to be safe and effective for the treatment of supraventricular arrhythmias. The aim of this prospective study was to report the feasibility and safety of catheter-based cryoablation for the treatment of postinfarction and idiopathic ventricular tachycardia (VT). Methods and Results: Catheter-based cryoablation was performed in 17 patients (15 men, 58 ± 18 years). VT occurred after a prior myocardial infarction in 10 and was idiopathic in 7 patients. Cryoablation was performed with a 10-F, 6.5-mm tipped catheter. The ablation site was selected using entrainment mapping techniques for postinfarction VT. The site of the earliest activation time with optimal pace mapping was used for ablation of idiopathic VT. All targeted VTs (12 postinfarction and 7 idiopathic) were acute successfully ablated after a median number of 2 applications of 5 minutes with an average temperature of –82 ± 4°C. Mean procedure and fluoroscopy times were 204 ± 52 and 52 ± 20 minutes for postinfarction VT and 203 ± 24 and 38 ± 15 minutes for idiopathic VT. No cryocatheter or cryoenergy complications were observed. After a follow-up of 6 months, 4 of the 10 patients with postinfarction VT had a recurrence. In 1 of the 7 patients with idiopathic VT the index arrhythmia recurred. Conclusion: In this small patient population, catheter-based cryoablation of VT was safe and effective. Future studies are needed to evaluate the effect of cryothermy in a larger group of patients, especially those with postinfarction VT. (J Cardiovasc Electrophysiol, Vol. 21, pp. 255–261, March 2010)

INTRODUCTION: Pulmonary vein (PV) isolation is considered as a key to atrial fibrillation (AF) treatment. Cryoballoon ablation is an effective therapy for PV isolation for AF with minimal side effects and was approved by the US Food and Drug Administration (FDA) several years ago. Successful isolation of PVs during cryoablation depends on the balloon temperature and helps in early identification of noneffective cryoballoon applications. A lower balloon temperature has been associated with long-term success in isolation of PVs.CASE PRESENTATION: At the start of the procedure, the cryoconsole displayed "low refrigerant level". After a few cycles of successful cryoballoon applications, for a fresh application for a new PV, the optimal temperature was not obtained in spite of obtaining good grade of occlusion and ostial positioning for right inferior pulmonary vein (RIPV). Later, immediately after changing the refrigerant cylinder, suitable temperature was obtained. We faced this situation thrice in a span of eight months.CONCLUSION: Low refrigerant level may cause nonoptimal temperature during cryoablation, which can be resolved by premature change of a gas cylinder.

Background— Idiopathic left bundle-branch block (LBBB)–like ventricular tachycardia (VT) is considered to originate in the right ventricular outflow tract (RVOT) or from the aortic root. Both regions are derived from the embryonic outflow tract. We now report that also the pulmonary trunk can give rise to VT, suggesting a common etiology of these tachycardias. Methods and Results— We studied 6 patients with symptomatic idiopathic LBBB-VT using electrophysiological mapping techniques. The VT origin was determined by analyzing the electrograms and the angiographic location of the catheter tip at the successful ablation site or the earliest activation site. Eight VTs were induced. Two VTs, with a mean earliest endocardial activation time of −5 and −20 ms and optimal pace mapping, were successfully ablated in the RVOT. In the remaining 6 VTs, the earliest activation site was found in the pulmonary artery, and, at this site, a sharp potential was present −38±12 ms before the QRS in 5 VTs. The mean earliest endocardial activation time in the RVOT was −1±2 ms. Ablation was attempted in 5 of 6 VTs and resulted in an acutely successful procedure. After a mean follow-up of 10±4 months, 1 of 5 patients had a recurrence. Conclusions— The site of origin of idiopathic LBBB-VT can be in the root of the pulmonary artery, suggesting a myocardial connection from this site to the RVOT. If no good criteria for ablation in the RVOT are found, detailed mapping of the pulmonary artery should be performed.

OBJECTIVE—To describe the electrocardiographic and electrophysiological findings of new atrial flutter developing in patients taking class IC antiarrhythmic drugs for recurrent atrial fibrillation, and to report the long term results of right atrial isthmus ablation in relation to the ECG pattern of spontaneous atrial flutter. DESIGN—Retrospective analysis. SETTING—Tertiary care academic hospital. PATIENTS—24 consecutive patients with atrial fibrillation (age 54 (12) years; 5 female, 19 male) developing atrial flutter while taking propafenone (n = 12) or flecainide (n = 12). RESULTS—The ECG was classified as typical (n = 13; 54%) or atypical atrial flutter (n = 8) or coarse atrial fibrillation (n = 3). Counterclockwise atrial flutter was the predominant arrhythmia. Acute success after isthmus ablation was similar in patients with typical (12/13) and atypical (8/8) atrial flutter. After long term follow up (13 (6) months, range 6-26 months), continuation of antiarrhythmic drug treatment appeared to result in better control of recurrences of atrial fibrillation in patients with typical atrial flutter (11/13) than in those with atypical atrial flutter (4/8), but the difference was not significant. Ablation for coarse atrial fibrillation was unsuccessful. CONCLUSIONS—New atrial flutter developing in patients taking class IC antiarrhythmic drugs for recurrent atrial fibrillation has either typical or atypical flutter wave morphology on ECG. The endocardial activation pattern and the acute results of ablation suggest that the flutter circuit was located in the right atrium and that the isthmus was involved in the re-entry mechanism. There appeared to be better long term control of recurrent atrial fibrillation in patients with typical (85%) as compared with atypical atrial flutter (50%). Patients developing coarse atrial fibrillation may not be candidates for this strategy. Keywords: atrial flutter; antiarrhythmic agents; fibrillation; ablation

Cryoablation of the Proximal AV Node. Introduction: Radiofrequency (RF) is the most commonly used energy source for the treatment of cardiac arrhythmias. Surgical experience has shown that cryoablation also is effective for ablating arrhythmias. The aims of this study were to (I) investigate the feasibility of inducing permanent complete AV block (CAVB). (2) investigate the value of cold mapping to select the cryoablation site to produce permanent CAVB, (3) study the macro- and microscopic lesion characteristics 6 weeks later, and (4) compare them to those produced with RF energy. Methods and Results: A new steerable 8.5-French bipolar electrode catheter having a thermocouple with a 3-mm tip using N2O as the refrigerant controlled by a cryoconsole was used. Six mongrel dogs were anesthetized, and the catheter was positioned via the femoral vein across the tricuspid valve to record a large low right atrial and a small His-bundle potential. After cold mapping (-15° to -20°C tip temperature) resulted in ECG modifications, cryothermia (-70°C) was given twice, lasting 5 minutes each, to create permanent CAVB (Cryo group). Additionally, RF catheter ablation of the AV node was performed in two anesthetized mongrel dogs (RF group). In the Cryo group, a permanent proximal CAVB was created in four dogs (block occurred within 10 to 20 sec of cryothermia). Permanent right bundle branch block was obtained in one dog and transient CAVB in the remaining dog. In both dogs of the RF group, permanent CAVB was obtained. The cryolesions consisted of well-circumscribed, homogeneous areas of fibrotic tissue without viable cardiomyocytes. Lesions produced with RF were less circumscribed and inhomogeneous, with clear evidence of viable cardiomyocytes and cartilage formation (patchy lesions). Conclusions: (1) Permanent CAVB can he created by using a steerable cryoablation catheter. (2) Histologically, cryoablated sites were homogeneous and showed fibrotic tissue without signs of chronic inflammation and no evidence of viable myocytes. (3) Lesions created with RF were less homogenous and still contained viable myocytes within the lesion and cartilage formation. (4) The arrhythmogenic significance of these differences requires further study. (5) The technology of using reversible cold mapping has the potential to identify the successful ablation site and warrants further clinical study.

Purpose Catheter-based cryoablation (cryo) has proven to be as effective as radiofrequency energy (RF) ablation for the treatment of arrhythmias. Nevertheless, the duration of cryoapplications has been reported as being significantly longer than RF applications. Methods Thirty-seven consecutive patients (28 men; mean age 59 ± 14 years) with typical atrial flutter (AFL) underwent cryo of the cavotricuspid isthmus (CTI). Applications of 1 min were delivered with a 10-French, 10-mm tipped catheter (CryoCor™). If bidirectional CTI block was not obtained after 12 1-min applications, applications of 3 min were selectively delivered to areas of conduction breakthrough. The endpoint of the procedure was creation of bidirectional CTI block and non-inducibility of AFL. Results A median of 7 (range 3 to 12) 1-min applications were given along the CTI with a mean temperature of −88.6 ± 2.3°C. Mean fluoroscopy and procedure time were 27 ± 14 min and 110 ± 28 min respectively. Five patients required additional 3-min applications; in one patient an overextended ablation catheter prevented the completion of the index-procedure. The acute success rate of the index-procedure was 97%. In 12/24 patients, two with AFL recurrence, resumption of CTI conduction was found 4 months post-ablation. In all patients bidirectional CTI block was re-obtained after a median of one 1-min application. No additional AFL recurrences occurred, after a mean follow-up of 37 ± 3 (range 30 to 44) months. Conclusions Cryo of AFL can successfully be performed using the same application duration as used for RF ablation. Both acute and long-term results are comparable to RF ablation. AFL recurrences occurred in only a minority of patients with resumption of CTI conduction.

Objective Recent literature has shown that common type atrial flutter (AFL) can recur late after cavotricuspid isthmus (CTI) catheter ablation using radiofrequency energy (RF). We report the long term outcome of a large group of patients undergoing CTI ablation using cryothermy for AFL in a single center. Methods Patients with AFL referred for CTI ablation were recruited prospectively from July 2001 to July 2006. Cryoablation was performed using a deflectable, 10.5 F, 6.5 mm tip catheter. CTI block was reassessed 30 min after the last application during isoproterenol infusion. Recurrences were evaluated by 12-lead ECG and 24 h Holter recording every clinic visit (1/3/6/9 and 12 months after the procedure and yearly thereafter) or if symptoms developed. Results The 180 enrolled patients had the following characteristics: 39 women (22%), mean age 58 years, no structural heart disease in 86 patients (48%), mean left atrium diameter 44 ± 7 mm and mean left ventricular ejection fraction 57 ± 7%. The average number of applications per patient was 7 (3 to 20) with a mean temperature and duration of −88°C and 3 min, respectively. Acute success was achieved in 95% (171) of the patients. There were no complications. After a mean follow-up of 27 ± 17 (from 12 to 60) months, the chronic success rate was 91%. The majority of the recurrences occurred within the first year post ablation. One hundred and twenty three patients had a history of atrial fibrillation (AF) prior to CTI ablation and 85 (69%) of those remained having AF after cryoablation. In 20 of 57 (35%) patients without a history of AF prior to CTI ablation, AF occurred during follow-up. Conclusions This prospective study showed a 91% chronic success rate (range 12 to 60 months) for cryoablation of the CTI in patients with common type AFL and ratified the frequent association of AF with AFL.