Shorter RSPV cryoapplications result in less phrenic nerve injury and similar 1-year freedom from atrial fibrillation.

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 (<2 minutes) resulted in less phrenic nerve injury (PNI) without compromising acute isolation efficacy for the right PVs. We now report the 1-year follow-up results regarding safety and efficacy of shorter cryoballoon applications. METHODS: A total of 222 patients with AF were randomized to two applications of 1 min "short," 2 min "medium," or 3 min "long" duration, 74 per group. Recurrence of AF and PV reconduction at 1-year follow-up were assessed. RESULTS: The overall 1-year freedom from AF was 79% and did not differ significantly between the short, medium, and long application groups (77%, 74%, and 85% for short, medium, and long application groups, respectively; P = 0.07). In 30 patients, a redo PVI procedure was performed. For all four PVs, there was no significant difference in reconduction between the three groups. Reconduction was most common in the left superior PV (57%). The right superior PV (RSPV) showed significantly less reconduction (17%) compared to the other PVs. CONCLUSIONS: Shortening cryoballoon applications of the RSPV to <2 minutes results in less PNI, while acute success and 1-year freedom from AF are not compromised. Therefore, shorter cryoballoon applications (especially) in the RSPV could be used to reduce PNI.

Mechanical circulatory support for life-threatening arrhythmia: A systematic review.

BACKGROUND: The use of temporary mechanical circulatory support (tMCS) during arrhythmia is increasing, although available evidence for this indication is limited, with significant gaps of knowledge regarding appropriate timing, management and configuration. This systematic review sought to analyze the use of tMCS in patients with life-threatening arrhythmia. METHODS: A systematic literature search identified 2529 references published until September 2019. Adult and pediatric patients diagnosed with all kind of life-threatening arrhythmia were included. tMCS was primarily compared to conventional non-tMCS therapies. Primary outcome measure was in-hospital or 30-day mortality. RESULTS: 19 non-randomized studies were selected, including 2465 adult and 82 pediatric patients. Primary outcome in tMCS patients varied widely (4-62%) with differences based on the use of prophylactic tMCS (4-21%) or rescue tMCS (58-62%). A substantial mortality benefit was observed among high-risk patients, as identified with PAINESD risk score or suffering from electrical storm and treated with prophylactic tMCS. During ablation procedures, tMCS patients showed higher rates of induced ventricular tachycardias (VTs), ablated VTs, VT termination and non-inducibility after ablation. Extracorporeal membrane oxygenation (ECMO) was applied in pediatric cases as hemodynamic protection for aggressive antiarrhythmic medical treatment with >80% survival. CONCLUSIONS: Prophylactic tMCS is associated with improved survival as compared to rescue or no-tMCS in patients with life-threatening arrhythmia, and may be considered in patients with high PAINESD risk score or suffering from electrical storm. ECMO can be advised as rescue and support therapy in pediatric cases requiring aggressive antiarrhythmic medical treatment.

Shorter cryoballoon applications times do effect efficacy but result in less phrenic nerve injury: Results of the randomized 123 study.

BACKGROUND: The second-generation cryoballoon significantly improves outcome of pulmonary vein isolation (PVI) but may cause more complications than the first generation. Currently, no consensus regarding optimal cryoballoon application time exists. The 123-study aimed to assess the minimal cryoballoon application duration necessary to achieve PVI (primary endpoint) and the effect of application duration on prevention of phrenic nerve injury (PNI). METHODS: Patients <75 years of age with paroxysmal atrial fibrillation, normal PV anatomy, and left atrial size <40 cc/m² or <50 mm were randomized to two applications of different duration: "short," "medium," or "long." A total of 222 patients were enrolled, 74 per group. RESULTS: Duration per application was 105 (101-108), 164 (160-168), and 224 (219-226) s and isolation was achieved in 79, 89, and 90% (P < 0.001) of the PVs after two applications in groups short, medium, and long, respectively. Only for the left PVs, the success rate of the short group was significantly less compared to the medium- and long-duration groups (P < 0.001). PNI during the procedure occurred in 19 PVs (6.5%) in the medium and in 20 PVs (6.8%) in the long duration groups compared to only five PVs (1.7%) in the short duration group (P < 0.001). CONCLUSIONS: Short cryoballoon ablation application times, less than 2 min, did affect the success for the left PVs but not for the right PVs and resulted in less PNI. A PV tailored approach with shorter application times for the right PVs might be advocated.

Hemoptysis After Cryoablation for Atrial Fibrillation.

AIM: Cryoballoon is a widely used tool for ablation for atrial fibrillation (AF). There are several complications after cryoablation. This paper assesses the incidence rate and severity of hemoptysis after cryo ablation for AF. METHODS: For current systemic review and meta-analysis, literature has been reviewed from 2008 to 2019 focusing on the incidence of hemoptysis after cryoballoon ablation for atrial fibrillation catheter ablation in PubMed, Cochrane library and EMBASE databases. RESULTS: This meta-analysis included 3534 patients from 20 studies; of mean age 54.0 ± 10.9 years. All patients had cryoballoon ablation for paroxysmal or persistent AF refractory to treatment and follow up duration for 8.2 ± 5.9 months with mean procedure duration of 153.4± 65.4 minutes. The mean cryoablation duration was 869.4 ± 148 sec with mean temperature of -59.7 ± 5.1 °C and a total of 109 patients (3.08%) had hemoptysis which was mild in the majority of cases (76.1%), mild to moderate in 20.2% and severe in only 3.7%. Hemoptysis onset was at 29.0 ± 56.5 day with median of 7 days, range (2 hours to 210 days). In 11 studies hemoptysis occurred early in 51 patients (95% CI for I2 was 0.0% to 0.0, P =0.95, I2 was 0.0%), but in 9 studies, hemoptysis occurred late in 58 patients (95% CI for I2 was 0.0% to 0.0, P =0.96, I2 was 0.0%). CONCLUSIONS: Mild hemoptysis is experienced by significant number of cryoballoon AF ablation patients and severe type in 3.5 % attributed to significantly lower temperature in inferior pulmonary veins and is more often associated with bigger cryoballoon.

Headache during cryoballoon ablation for atrial fibrillation.

AIMS: Headache has been reported to occur during cryoballoon ablation for atrial fibrillation (AF). No study has systematically analysed this phenomenon. METHODS AND RESULTS: Twenty consecutive patients with symptomatic AF underwent cryoballoon ablation without sedation. Headache was evaluated before, during, and after the first cryoapplication in every pulmonary vein (PV) using a visual representation of a head for location of the headache, a numerical rating scale (NRS) for measuring pain intensity and the short-form McGill pain questionnaire (MPQ) for qualitative analysis of pain. The order in which the PVs were ablated was randomized. Sixteen (80%) patients perceived mainly frontal headache during cryoablation. The overall NRS scores were significantly higher during (5.1 ± 1.7), compared with before (2.7 ± 1.4), and after (3.5 ± 2.2) a cryoapplication (P < 0.05). The NRS score was significantly higher during ablation of the first PV. The intensity of the perceived headache was not related to the temperature reached 150 s after initiation of a cryoapplication (P = 0.81). Of the MPQ, three sensory adjectives and one affective adjective averaged between scores 1 and 2, representing mild-to-moderate severity of pain. CONCLUSION: The majority of patients treated by balloon cryoablation experienced headache during a cryoapplication. There was no correlation between the temperature reached during a cryoballoon freeze and the intensity of the headache. Cryoballoon ablation of the first PV was significantly more painful than the remaining PVs.

Adenosine testing after second-generation cryoballoon ablation (ATSCA) study improves clinical success rate for atrial fibrillation.

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.

Failure to reach the optimal temperature during cryoablation due to refrigerant cylinder problem.

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.

Adenosine testing after second-generation balloon devices (cryothermal and laser) mediated pulmonary vein ablation for atrial fibrillation.

AIMS: 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. METHODS: 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. RESULTS: 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 %). CONCLUSION: 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.

Is the 12-lead electrocardiogram during antidromic circus movement tachycardia helpful in predicting the ablation site in atriofascicular pathways?

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 (<-30°). During ADT axis was superior (-57° ± 10°) in 15 (31%), horizontal (-11° ± 14°) in 22 (46%), and normal (+45° ± 16°) in 11 (23%) patients. The correct ablation site did not differ between the different groups of QRS axis. QRS width during ADT was narrower in patients with a normal when compared with a horizontal and leftward axis (127 ± 14 vs. 145 ± 12 ms, P < 0.0001), and the V-H interval was shorter (4 ± 3 ms vs. 19 ± 22 ms, P = 0.03). CONCLUSIONS: There was no correlation between the AF pathway ablation site and the QRS axis during ADT. The 12-lead ECG during maximal pre-excitation does not predict the proper site of tricuspid annulus ablation in patients with A-V conduction over an AF pathway.

Coronary spasm during cardiac electrophysiological study following isoproterenol infusion.

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.

Management Of Pulmonary Vein Stenosis Following Catheter Ablation Of Atrial Fibrillation.

There is limited literature available regarding PV (pulmonary vein) stenosis management. Starting from its incidence, subsequent follow up using imaging technologies to monitor the success and the way of managing different groups pose varied opinions. However, with newer technological advancements and better understanding of mechanism of the atrial fibrillation ablation, the incidence of PV stenosis secondary to catheter ablation is declining. This paper highlights the current trends and future of management of PV stenosis secondary to catheter ablation for atrial fibrillation.

Atrial premature beats during decrementally conducting antidromic tachycardia.

BACKGROUND: Advancement of ventricular activation by an atrial premature beat (APB) given during His bundle refractoriness followed by resetting of an antidromic tachycardia (AT) in patients with decrementally conducting accessory pathway (DAP) is a helpful maneuver to prove pathway existence and participation in the circuit. We aim to assess in a large cohort the role of APB during AT in patients with a DAP. METHODS AND RESULTS: Thirty-three patients with a DAP having 34 AT were included in the study: 29 patients had an atriofascicular pathway, 1 had a long atrioventricular DAP, and 4 had a short atrioventricular fiber. APBs were delivered initially from the lateral right atrium, scanning diastole with a 10-ms decrement until AT termination or refractoriness. We observed 4 patterns of response after APB during AT: advancement of activation (29 cases), delay (2), advancement followed by delay (3), and termination (7). Eight patients required an earlier APB to advance or delay ventricular activation. These 8 patients had a shorter AT cycle length (median of 273 versus 315 ms; P=0.003) and had a shorter resetting zone (median coupling interval of 30 versus 50 ms; P=0.01). CONCLUSIONS: APB delivered during AT in patients with a DAP advanced and/or delayed ventricular activation in all patients. In 1 of 5 of cases the AT was terminated by a single APB. In approximately a quarter of the patients an earlier coupled APB was needed to reset AT. The high RA was an adequate stimulation site in all right-sided DAP.

Patients originally diagnosed with idiopathic atrial fibrillation more often suffer from insidious coronary artery disease compared to healthy sinus rhythm controls.

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 <.001), had a higher prevalence of smoking (25% vs 14%, P = .021), higher fasting blood glucose levels (5.5 ± 0.7 mmol/L vs 5.4 ± 0.6 mmol/L, P = .025), and smaller atrial diameters (37 ± 4 mm vs 40 ± 5 mm, P <.001) compared to AF patients. Notwithstanding the above, idiopathic AF patients significantly more often suffered from subclinical CAD compared to controls (49% vs 34%, P = .008). Multivariable regression analysis revealed that beside (as expected) age and gender, a history of AF and left atrial diameter were significant predictors of underlying CAD. CONCLUSION: Half of patients originally diagnosed with idiopathic paroxysmal AF show concealed underlying CAD. The detection and treatment of CAD at an early stage could improve the prognosis of these patients.

Comparison of a 6.5, 10, and 15 mm cryoablation catheter-tip for the treatment of common atrial flutter.

AIM: Only a few studies have investigated the effect of large tip sizes for catheter-based cryoablation (cryo). This study evaluates the safety and efficacy of cryo of the cavotricuspid isthmus (CTI) using three cryocatheter-tip sizes. METHODS AND RESULTS: Forty-five consecutive patients with common atrial flutter (AFL) underwent cryo of the CTI using a 6.5, a 10, or a novel 15 mm catheter-tip. Single applications of 3 min were delivered at each site along the CTI. Baseline characteristics of the three groups were comparable. The overall acute success rate was 89% and there was no difference with respect to the tip electrode size (P > 0.05). Fewer applications were required for a 10 mm (6 ± 2, range 3-7) and a 15 mm (6 ± 1, range 4-8) compared with a 6.5 mm catheter-tip (8 ± 3, range 4-14; P < 0.05). Procedure time was significantly shorter with the largest tip electrode (89 ± 26 min vs. 132 ± 28 min (6.5 mm tip), P < 0.05). No complications occurred. After a mean follow-up of 51 ± 5 months, 43 patients (96%) were without recurrence of AFL. CONCLUSIONS: A large (10 or 15 mm) cryoablation catheter-tip requires significantly fewer applications to create bidirectional CTI block compared with a 6.5 mm tip. A significant decrease in procedure time with preservation of the overall safety and efficacy supports the preference of a 15 over a 6.5 mm catheter-tip for cryoablation of AFL.

A suddenly lethal accessory pathway.

A 17-year-old girl was diagnosed with an asymptomatic Wolff-Parkinson-White pattern just before a major orthopedic operation. Three months after the surgery, she developed ventricular fibrillation-being the first manifestation of her Wolff-Parkinson-White syndrome. The patient was successfully reanimated. radiofrequency ablation permanently interrupted conduction over a right posteroseptal accessory pathway.

Patients using vitamin K antagonists show increased levels of coronary calcification: an observational study in low-risk atrial fibrillation patients.

AIMS: Vitamin K antagonists (VKA) are currently the most frequently used drug to prevent ischaemic stroke in atrial fibrillation (AF) patients. However, VKA use has been associated with increased vascular calcification. The aim of this study was to investigate the contribution of VKA use to coronary artery calcification in low-risk AF patients. METHODS AND RESULTS: A prospective coronary calcium scan was performed in 157 AF patients without significant cardiovascular disease (108 males; mean age 57 ± 9 years). A total of 71 (45%) patients were chronic VKA users. The duration of VKA treatment varied between 6 and 143 months (mean 46 months). No significant differences in clinical characteristics were found between patients on VKA treatment and non-anticoagulated patients. However, median coronary artery calcium scores differed significantly between patients without and patients with VKA treatment [0, inter-quartile range (IQR) 0-40, vs. 29, IQR 0-184; P = 0.001]. Mean coronary calcium scores increased with the duration of VKA use (no VKA: 53 ± 115, 6-60 months on VKA: 90 ± 167, and >60 months on VKA: 236 ± 278; P < 0.001). Multivariable logistic regression analysis revealed that age and VKA treatment were significantly related to increased coronary calcium score. CONCLUSION: Patients using VKA show increased levels of coronary calcification. Age and VKA treatment were independently related to increased coronary calcium score.