Predictors of AVNRT Recurrence After Slow Pathway Modification.

Atrioventricular nodal reentry tachycardia (AVNRT) is the most common regular supraventricular tachycardia (SVT). Slow pathway modification (SPM) is the accepted first line treatment with reported success rates around 95%. Information regarding possible predictors of AVNRT recurrence is scarce.Out of 4170 consecutive patients with SPM in our department from 1993-2018, we identified 78 patients (1.9%) receiving > 1 SPM (69% female, median age 50 years) with a recurrence of AVNRT after a successful SPM. We matched these patients for age, gender and number of radiofrequency applications during first SPM with 78 patients who received one successful SPM in our center without AVNRT recurrence. Both groups were analyzed for possible predictors of a recurrence of AVNRT during long-term follow-up. The recurrence group contained a significantly lower proportion of patients with an occurrence of junctional beats during SPM (69% versus 89%, P = 0.006). Moreover, significantly more cases of previously diagnosed atrial fibrillation/tachycardia (AF/AT; 21% versus 5%, P = 0.007) and inducible AF/AT during electrophysiology study (23% versus 6%, P = 0.006) were present in the recurrence group. While more than half of patients had a recurrence within the first year, in 20% symptoms reappeared ≥ 4 years after ablation.In a small percentage of patients, AVNRT recurs after an initially successful ablation. Interestingly, these patients had significantly fewer junctional beats during ablation and a higher rate of other (inducible) arrhythmias. AVNRT recurrence spanned a considerable timeframe and should remain a differential diagnosis, even years after ablation.

Long-term experience of atrioventricular node ablation in patients with refractory atrial arrhythmias.

Atrial fibrillation and other atrial tachyarrhythmias are increasing with age and concomitant morbidity. First options in symptomatic patients are drug treatment and catheter ablation. Nevertheless, a considerable number of patients suffer from refractory atrial tachyarrhythmias despite treatment. Atrioventricular node ablation (AVNA) may be helpful in many of these patients. Therefore, we investigated AVNA patients with a long-term follow-up. We enrolled 82 patients with a follow-up longer than 1 year receiving AVNA for drug- and ablation-resistant atrial tachyarrhythmias (AA) in a retrospective manner. Mean follow-up duration was 48 ± 24 months. 50% of the patients initially received AVNA to optimize biventricular pacing in cardiac resynchronization therapy, the other 50% because of refractory symptomatic tachyarrhythmias. Persistent AV block was achieved in every patient. Symptom relief and patient satisfaction were high during follow-up. Due to system upgrades there were 63% of patients with a biventricular system during follow-up. In these patients, left-ventricular ejection fraction (LV-EF) increased by 7% (42-49%) after ablation. AVNA is effective in increasing biventricular pacing as well as for symptom relief in patients with refractory atrial tachyarrhythmias. AVNA should be considered as a valuable option in patients with refractory atrial tachyarrhythmias lacking other treatment options.

Inadvertent transseptal puncture into the aortic root: the narrow edge between luck and catastrophe in interventional cardiology.

AIMS: Inadvertent puncture of the aortic root (AR) is a well-known complication of transseptal puncture (TSP). Strategies for handling of this potentially lethal complication have not been identified yet. In this study, we present typical anatomical locations and clinical management of aortic root puncture (ARP) due to TSP. METHODS AND RESULTS: All patients with ARP were retrospectively collected from seven hospitals. Aortic root puncture was identified and classified regarding angiographical and intraoperative findings in cardiac surgery: (i) TSP from the right atrium (RA) to the non-coronary sinus (NCS), (ii) TSP from RA to the non-coronary sinutubular junction (STJ), and (iii) TSP from RA to the ascending aorta (AA). A total of 24 patients with inadvertent ARP were identified. In 19 patients, penetration of the aorta was accomplished by the inner dilator, in 5 patients by the complete sheath. Previous cardiac surgery had been performed in six patients. There were 13 RA-to-NCS punctures, 2 RA-to-STJ punctures, and 9 RA-to-AA punctures. No cardiac tamponade (CT) occurred in patients with RA-to-NCS and RA-to-STJ punctures. In 8 of 9 patients with RA-to-AA puncture, CT occurred immediately requiring urgent pericardiocentesis and surgical repair. Two patients died after surgical repair. In the 16 patients without surgical therapy, no shunt from the AR to the RA was observed 3 months after the procedure. CONCLUSION: Aortic root puncture due to mislead TSP via NCS or STJ is usually not associated with a severe clinical course while ARP into the AA via the epicardial space generally leads to CT requiring surgical repair.

Broad antiarrhythmic effect of mexiletine in different arrhythmia models.

Aims: Experimental studies and clinical reports suggest antiarrhythmic properties of mexiletine in different arrhythmias. We aimed at investigating mexiletine in experimental models of atrial fibrillation (AF) as well as in long-QT- (LQTS) and short-QT-syndrome (SQTS). Methods and results: In 15 isolated rabbit hearts, erythromycin (300 µM) was infused for simulation of long-QT-2-syndrome. In further 13 hearts, veratridine was administered to simulate long-QT-3-syndrome. Both drugs induced a significant QT-prolongation (erythromycin: +87 ms, P < 0.01; veratridine: +19 ms, P < 0.05) and increased dispersion of repolarization (erythromycin: +55 ms, P < 0.01; veratridine +31 ms, P < 0.01). Additional infusion of mexiletine (25 µM) resulted in a significant reduction of dispersion (erythromycin: -43 ms, P < 0.01; veratridine: -26 ms, P < 0.05). Reproducible induction of torsade de pointes was observed in 13 of 15 erythromycin-treated hearts (192 episodes) and 6 of 13 veratridine-treated hearts (36 episodes). Additional infusion of mexiletine significantly reduced ventricular tachycardia (VT) incidence. With mexiletine, only 3 of 15 erythromycin-treated hearts (27 episodes) and 1 of 13 veratridine-treated hearts (2 episodes) presented polymorphic VT. In additional 9 hearts, the IK-ATP-channel-opener pinacidil was employed to simulate SQTS and significantly abbreviated ventricular repolarization (QT-interval: -18 ms, P < 0.05) and enhanced induction of ventricular fibrillation (VF). Mexiletine reversed the effects of pinacidil, increase refractory period (+127 ms, P < 0.01) and significantly suppressed induction of VF. In further 13 hearts AF was induced by combined treatment with acetylcholine/isoproterenol. Mexiletine also increased atrial refractory period (+80 ms, P < 0.01) and thereby effectively suppressed atrial fibrillation. Conclusion: Acute infusion of mexiletine significantly reduced the occurrence of polymorphic VT in the presence of pharmacologically simulated LQTS. Furthermore, mexiletine demonstrated potent antiarrhythmic properties in a model of SQTS and in AF.

Incidence and management of inadvertent puncture and sheath placement in the aorta during attempted transseptal puncture.

AIMS: Transseptal punctures (TSP) are routinely performed in cardiac interventions requiring access to the left heart. While pericardial effusion/tamponade are well-recognized complications, few data exist on accidental puncture of the aorta and its management and outcome. We therefore analysed our single centre database for this complication. METHODS AND RESULTS: We assessed frequency and outcome of inadvertent aortic puncture during TSP in consecutive patients undergoing ablation procedures between January 2005 and December 2014. During the 10-year period, two inadvertent aortic punctures occurred among 2936 consecutive patients undergoing 4305 TSP (0.07% of patients, 0.05% of TSP) and in one Mustard patient during attempted baffle puncture. The first two patients required left ventricular access for catheter ablation of ventricular tachycardia. In both cases, an 11.5F steerable sheath (inner diameter 8.5F) was accidentally placed in the ascending aorta just above the aortic valve. In the presence of surgical standby, the sheaths were pulled back with a wire left in the aorta. Under careful haemodynamic and echocardiographic observation, this wire was also pulled back 30 min later. None of the patients required a closing device or open heart surgery. None of the patients suffered complications from the accidental aortic puncture and sheath placement. CONCLUSION: Inadvertent aortic puncture and sheath placement are rare complications in patients undergoing TSP for interventional procedures. Leaving a guidewire in place during the observation period may allow introduction of sheaths or other tools in order to control haemodynamic deterioration.

Data on procedural handling and complications of pulmonary vein isolation using the pulmonary vein ablation catheter GOLD®.

AIMS: The second-generation multi-electrode-phased radiofrequency pulmonary vein ablation catheter (PVAC GOLD(®)) was redesigned with the intent to improve its safety and efficacy. METHODS AND RESULTS: Using a prospectively designed single-centre database, we retrospectively analysed 128 consecutive patients (102 paroxysmal and 43 female) who underwent their first pulmonary vein isolation with the PVAC GOLD(®). The analysis focused on procedural data as well as in-hospital complications. Baseline characteristics of the patient collective were as follows: mean age 57.9 years, mean CHA2DS2-VASC was 1.73 ± 1.30; structural heart disease was present in seven patients. The PVAC GOLD(®) exhibited procedure durations of 123.1 min ± 27.9, duration of energy delivery was 18.3 min ± 11.4, and fluoroscopy duration was 16.0 min ± 7.7. The redesigned catheter shows major complication [major bleeding, transitory ischaemic attack (TIA), and pericardial tamponade] rates of 2.3% (n = 3). The overall rate of adverse events was 5.4% (n = 7). Bleeding complications were observed in three patients (2.3%), in particular there were two cases (1.6%) of minor bleeding and one case (0.8%) of major bleeding. Two patients suffered pericardial effusion, but there was no need for pericardiocentesis. Besides one TIA, there was no other thrombo-embolic event. Furthermore, one case of post-procedural fever was observed. No deaths, stroke, or haemorrhagic shock occurred. Of the 510 pulmonary veins, 508 could be reached with the PVAC GOLD(®) device using a non-steerable long sheath. CONCLUSION: The PVAC GOLD(®) seems to have an acceptable safety profile. The handling is comparable with the previous generation PVAC(®).

Esophageal and Mediastinal Lesions Following Multielectrode Duty-Cycled Radiofrequency Pulmonary Vein Isolation: Simple Equals Safe?

BACKGROUND: The development of esophageal lesions following atrial fibrillation (AF) ablation has frequently been reported. Mediastinal tissue layers and the posterior wall of the left atrium are in close proximity to the site of ablation. Hence, mucosal lesions might solely represent the "tip of the iceberg." We therefore investigated patients undergoing multielectrode phased radiofrequency (RF) ablation (PVAC®, Medtronic Inc., Minneapolis, MN, USA) for symptomatic AF by radial endosonography (EUS) in conjunction with conventional endoscopy esophago-gastro-duodenoscopy (EGD) to visualize potential mediastinal injuries following pulmonary vein isolation (PVI). METHODS AND RESULTS: Eighteen patients (six women, mean age 52.8 ± 12.8 years, range 32-72 years) underwent PVI using multielectrode phased RF ablation and EGD and EUS following PVI within 48 hours. Postablation periesophageal lesions were detected by EUS in 10 out of 18 patients (56%). Four out of 10 lesions consisted of mild changes like small pericardial effusions, whereas six out of 10 patients had more severe lesions of the mediastinum, including one patient with changes of the esophageal mucosa. No atrio-esophageal fistula developed during follow-up (FU; mean FU 215 ± 105 days). CONCLUSIONS: Mediastinal and esophageal structural changes occurred in a substantial number of patients. These findings highlight the necessity of close FU and the awareness of the potential development of an atrio-esophageal fistula also after multielectrode catheter ablation.

The young patient with asymptomatic atrial fibrillation: what is the evidence to leave the arrhythmia untreated?

Atrial fibrillation (AF) is the most common arrhythmia and has gained increasingly more attention due to new treatment options, particularly catheter ablation. Growing experience with this technique and better AF suppression compared with antiarrhythmic medication have paved the way for its extended use and indication. At this point, it is recommended for symptomatic patients if antiarrhythmic drugs failed and in selected young symptomatic patients as first line therapy. It is a tempting concept to improve prognosis in young AF patients by rhythm control irrespective of symptoms. In this review, we summarize epidemiological data on young AF, efficacy, and limitations of rate and rhythm control by means of medication and catheter ablation in young patients, information on arrhythmia progression and outcome, and the consequences of these data for AF treatment in young, asymptomatic patients.

Modified phased radiofrequency ablation of atrial fibrillation reduces the number of cerebral microembolic signals.

AIMS: Phased radiofrequency (RF) ablation for atrial fibrillation is associated with an increased number of silent cerebral lesions on magnetic resonance imaging and cerebral microembolic signals (MESs) on transcranial Doppler ultrasound imaging compared with irrigated RF. The increased rate of embolic events may be due to a specific electrical interference of ablation electrodes attributed to the catheter design. The purpose of this study was to elucidate the effect of deactivating the culprit electrodes on cerebral MESs. METHODS AND RESULTS: Twenty-nine consecutive patients (60 ± 11 years, 10 female) underwent their first pulmonary vein isolation using phased RF energy. Electrode pairs 1 or 5 were deactivated to avoid electrical interference between electrodes 1 and 10 ('modified'). Detection of MESs by transcranial Doppler ultrasound was performed throughout the procedure to assess cerebral microembolism. Results were compared with the numbers of MESs in 31 patients ablated using all available electrodes ('conventional') and to 30 patients undergoing irrigated RF ablation of a previous randomized study. Ablation with 'modified' phased RF was associated with a marked decrease in MESs when compared with 'conventional' phased RF (566 ± 332 vs. 1530 ± 980; P < 0.001). This difference was mainly triggered by the reduction of MES during delivery of phased RF energy, resulting in MES numbers comparable to irrigated RF ablation (646 ± 449; P = 0.7). Total procedure duration as well as time of RF delivery was comparable between phased RF groups. Both times, however, were significantly shorter compared with the irrigated RF group (123 ± 28 vs. 195 ± 38; 15 ± 4 vs. 30 ± 9; P < 0.001, respectively). CONCLUSION: Pulmonary vein isolation with 'modified' phased RF is associated with a decreased number of cerebral microembolism especially during the delivery of ablation impulses, supporting the significance of electrical interference between ablation electrodes 1 and 10. Deactivation of electrode pairs 1 or 5 might increase the safety of this approach without an increase in procedure duration or RF delivery time.

Role of implantable cardioverter defibrillator therapy in patients with acquired long QT syndrome: a long-term follow-up.

AIMS: The use of implantable cardioverter defibrillators (ICD) in patients with torsade de pointes (TdP) and ventricular fibrillation in the presence of acquired long QT syndrome (aLQTS) is under debate, partly due to the fact that aLQTS is potentially reversible and currently no long-term follow-up data are available. We aimed to evaluate the long-term follow-up of patients with acquired long QT syndrome (aLQTS) who had received an implantable cardioverter defibrillator (ICD) for secondary prevention of sudden cardiac arrest (SCA). METHOD AND RESULTS: Over a 10 year period, 43 patients with an ICD after survived cardiac arrest (SCA) due to an aLQTS were included [female n= 27 (63%); mean age 61 ± 16 years]. There was no clinical evidence for congenital LQTS (Schwartz score 1.25 ± 0.8). Structural heart disease was present in 29 patients (47%; ischaemic n= 13; dilated cardiomyopathy n= 9; mean EF 41%± 12). The most common proarrhythmic trigger happened to be antiarrhythmic drugs (n= 34; 79%). Other triggers included contrast agent (n= 1), haloperidol (n= 2), severe hypokalaemia (n= 2), drug abuse/alcohol (n= 2), and mere severe bradycardia (n= 2). Under trigger QTc interval measured 536 ± 58 vs. 438 ± 33 ms without trigger (P< 0.001). During a mean follow-up of 84 ± 55 months, appropriate shocks occurred in 19 patients (44%); inappropriate shocks in 13 patients (30%; only inappropriate n= 3). Appropriate shocks were almost as common in patients without as in those with structural heart disease (35 vs. 48%; P= 0.32). None of the patients were re-exposed to the initial trigger during the follow-up period. Beta-blocker medication did not prevent ICD shocks (12 of 19 vs. 11 of 24 on medication). CONCLUSION: Appropriate ICD shocks are a common finding in patients with aLQTS and SCA irrespective of the underlying cause or structural heart disease. Thus, even in the presence of relevant acquired proarrhythmia ICD may be beneficial.

Atrial flutter in a patient with postoperative AV block and right infero-septal accessory pathway: how to preserve AV conduction.

We report a case of postoperative acquired atrioventricular (AV) block and successful ablation of isthmus-dependent atrial flutter using "cryomapping" in combination with a mapping system preserving AV conduction via right infero-septal accessory pathway.

The Incidence, Electrophysiological Characteristics and Ablation Outcome of Left Atrial Tachycardias after Pulmonary Vein Isolation Using Three Different Ablation Technologies.

BACKGROUND: Left atrial tachycardias (LAT) are a well-known outcome of pulmonary vein isolation (PVI). Few data are available on whether the catheter used to perform PVI influences the incidence, as well as the characteristics of post PVI LAT. We present data on LAT following PVI by the following three ablation technologies: (1) phased multi-electrode radiofrequency catheter (PVAC), (2) irrigated single-tip catheter (iRF), and (3) cryoballoon ablation. METHODS: Using a prospectively designed single-center database, we analyzed 650 patients (300 iRF, 150 PVAC, and 200 cryoballoon) with paroxysmal (n = 401) and persistent atrial fibrillation (AF), who underwent their first PVI at our center. RESULTS: The three populations were comparable in their baseline characteristics; however, the cryoballoon group comprised a higher percentage of patients with persistent AF (p = 0.05). The LAT rates were 3.7% in the iRF group (mean follow-up 22 ± 14 months), 0.7% in the PVAC group (mean follow-up 21 ± 14 months), and 4% in the cryoballoon group (mean follow-up 15 ± 8 months). The predominant mechanism of LAT was macro-reentrant tachycardia. Reconnection of at least one pulmonary vein was observed in 87% of the patients who underwent 3D mapping. No predictors for LAT occurrence were identified. CONCLUSION: The occurrence of LAT post PVI is rare; the predominant mechanism was macro-reentrant tachycardia. Reconnection of at least one pulmonary vein was observed in nearly all the LAT patients. In our retrospective analysis, the lowest rate of LAT was observed with the PVAC. No predictors for LAT occurrence were identified.

Thyroid Dysfunction under Amiodarone in Patients with and without Congenital Heart Disease: Results of a Nationwide Analysis.

Background: Amiodarone has a profound adverse toxicity profile. Large population-based analyses quantifying the risk of thyroid dysfunction (TD) in adults with and without congenital heart disease (ACHD) are lacking. Methods: All adults registered with a major German health insurer (≈9.2 million members) with amiodarone prescriptions were analyzed. Occurrence of amiodarone-associated TD was assessed. Results: Overall, 48,891 non-ACHD (37% female; median 73 years) and 886 ACHD (34% female; median 66 years) received amiodarone. Over 184,787 patient-years, 10,875 cases of TD occurred. The 10-year risk for TD was 38% in non-ACHD (35% ACHD). Within ACHD, compared to amiodarone-naïve patients, the hazard ratio (HR) for TD was 3.9 at 4 years after any amiodarone exposure. TD was associated with female gender (HR 1.42, p < 0.001) and younger age (HR 0.97 per 10 years, p = 0.009). Patients with congenital heart disease were not at increased risk (HR 0.98, p = 0.80). Diagnosis of complex congenital heart disease, however, was a predictor for TD (HR 1.56, p = 0.02). Amiodarone was continued in 47% of non-ACHD (38% ACHD), and 2.3% of non-ACHD (3.5% ACHD) underwent thyroid surgery/radiotherapy. Conclusions: Amiodarone-associated TD is common and comparable in non-ACHD and ACHD. While female gender and younger age are predictors for TD, congenital heart disease is not necessarily associated with an elevated risk.

Management of atrial fibrillation around the world: a comparison of current ACCF/AHA/HRS, CCS, and ESC guidelines.

New guidelines for the management of atrial fibrillation (AF) have recently been published by the American College of Cardiology Foundation/American Heart Association, and Heart Rhythm Society (ACCF/AHA/HRS) task force on practice guidelines, the Canadian Cardiovascular Society (CCS), and the European Society of Cardiology (ESC). Although they all refer to the same scientific data and agree in the majority of AF management, interpretation, and weighing of study results are quite different in some aspects. While recommendations for stroke risk assessment and prophylaxis are rather conservative in the ESC guidelines, the CCS guideline recommendations are more conservative with regard to lenient rate control and the ACCF/AHA/HRS recommendations are rather strict with regard to rhythm management.

Pulmonary vein variants predispose to atrial fibrillation: a case-control study using multislice contrast-enhanced computed tomography.

AIMS: Pulmonary veins (PV) play a pivotal role in atrial fibrillation (AF). Anatomical variants of PV have been described and related to a higher arrhythmogenic potential. The aim of this study was to compare the prevalence of PV variants and diameters of PV ostia in AF patients and controls. METHODS AND RESULTS: Variants of PV were defined as right or left common ostia (RCO, LCO), a right middle or right top PV . A long common trunk (LCT) was defined as an LCO with a distance to the first branching ≥ 10 mm. Multislice contrast-enhanced thoracic computed tomography was performed prior to AF ablation in 166 consecutive patients, 47.6% with paroxysmal, 52.4% with persistent AF, as well as in a sex- and age-matched control group without AF, for non-cardiological indications. Images were evaluated by two independent observers. The mean age was 59 ± 10 years, 108 were men (65.1%). A higher prevalence of LCO was found in the AF group: 33.7 vs. 19.9% (P= 0.004), odds ratio (OR) 2.1; 15.4% in patients vs. 10.2% in controls had an LCT (P= 0.14). No differences in other PV variants were found. The ostial diameters were greater in AF-patients (P< 0.001). CONCLUSIONS: To the best of our knowledge, the present study shows for the first time a higher prevalence of an LCO in patients with AF as compared with controls, with an OR of 2.1. This suggests a pre-disposing role of LCO in the development of AF.

Successful treatment of catecholaminergic polymorphic ventricular tachycardia with flecainide: a case report and review of the current literature.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disease that can cause sudden cardiac death due to ventricular fibrillation (VF). While pharmacological therapy with beta-blockers and/or Ca(2)(+) antagonists is often unreliable, a recent study has demonstrated that flecainide can effectively suppress arrhythmia in a murine model of CPVT as well as clinically in two human subjects suffering from CPVT. We here present the case of an 11-year-old boy suffering from CPVT-1 as well as a review of the current relevant literature. After resuscitation due to VF at age 9, an automated implantable cardioverter-defibrillator (ICD) was implanted in 2007. Under beta-blocker therapy, repeated shocks were delivered due to either fast ventricular tachycardia (VT) or VF. This persisted under additional therapy with verapamil. Implantable cardioverter-defibrillator routine interrogations showed frequent non-sustained VT with an average of 8.8 per day. Additionally, the patient suffered from impaired physical performance due to decreased chronotropic competence. In July 2009, flecainide was added to the beta-blocker/verapamil regimen, resulting in a plasma level of 0.20 mg/L. No ICD shock or sustained VT occurred until December 2010. Genetic testing revealed an RyR2 receptor mutation. The case demonstrates the challenge of diagnosis and management of CPVT. It furthermore supports recent experimental evidence that the class 1 antiarrhythmic drug flecainide can suppress CPVT. The presented case supports a novel strategy in treating CPVT with the class I antiarrhythmic agent flecainide.

Therapy of supraventricular and ventricular arrhythmias in adults with congenital heart disease-narrative review.

Arrhythmias are among the most common late complications in adults with congenital heart disease (ACHD) and a frequent reason for hospital admission. Both, supraventricular and ventricular arrhythmias, not only cause debilitating symptoms, but may be life-threatening by increasing risk of stroke, causing or worsening heart failure and being associated with sudden death. Substrate and risk for arrhythmia differs widely between congenital defects with specific arrhythmias being much more common in some patients than others. Atrial macroreentrant arrhythmias are particularly frequent in patients with atrial septal defects and repair that involves atrial incisions including patients with transposition of the great arteries (TGA) and atrial switch. Accessory pathways and related arrhythmias are often associated with Ebstein's anomaly and congenitally corrected TGA. Monomorphic ventricular arrhythmias occur in patients with ventricular incisions, namely patients with Tetralogy of Fallot. Changes in surgical repair techniques influence arrhythmia prevalence and substrate as well as anatomical access for catheter ablation procedures. In addition, epidemiologic changes associated with improved long-term survival will further increase the prevalence of atrial fibrillation in ACHD. This article summarizes current understanding of prevalence of specific arrhythmias, underlying mechanisms, medical and interventional treatment options and their outcome in ACHD.

Narrative review of: risk stratification and implantable cardioverter-defibrillator therapy in adults with congenital heart disease.

Fortunately, the population of adults with congenital heart disease (ACHD) is growing due to improved operation techniques. Life expectancy is continuously rising, nevertheless, sudden cardiac death is one of the leading causes of mortality in ACHD late after initial diagnosis. Risk stratification in ACHD remains challenging as large study results are missing, congenital defects and operation methods differ considerably between individual patients and results from acquired heart diseases are often not conferrable. The purpose of this narrative review is to objectively summarize the current knowledge on arrhythmogenic risk of ACHD and to give an overview on implantable cardioverter-defibrillator (ICD) therapy in this collective. Remarkable progress has been made in electrophysiological understanding of critical areas of slow conduction especially in patients with Tetralogy of Fallot (ToF). In patients with transposition of the great arteries after atrial baffling (Mustard/Senning procedure) atrial arrhythmias play a crucial role in sudden cardiac death. ICD therapy in ACHD may pose special technical challenges due to limited access for intracardiac leads. The introduction of the totally subcutaneous ICD improved therapeutic options for ACHD especially when contraindications for transvenous leads are present. Risk stratification in ACHD has to be seen as a team approach, requires thorough understanding of congenital heart defects and the operation techniques and needs unconventional technical approaches in some cases.

Impact of specialized electrophysiological care on the outcome of catheter ablation for supraventricular tachycardias in adults with congenital heart disease: Independent risk factors and gender aspects.

BACKGROUND: Limited data exist on the impact of gender and specialized care on the requirement of repeat treatment of supraventricular tachycardia (SVT) in adult patients with congenital heart disease (ACHDs). OBJECTIVE: The study aimed to assess independent predictors of a combined end point of re-catheter ablation (CA) or cardioversion at 3 years of follow-up, including the impact of gender and specialized ACHD care. METHODS: All ACHDs registered in a database of one of the largest German health insurers (≈9.2 million members) who underwent CA for SVT were analyzed. RESULTS: Of 38,892 ACHDs 16 years or older, 485 (49.5% women; median age 58.4 years; interquartile range 42.1-70.8 years) underwent CA for SVT. Over 3-year follow-up, the number of yearly CA procedures increased significantly, particularly for atrial fibrillation (+195%) and atrial flutter (+108%). Moderate to severe complexity heart disease (odds ratio [OR] 1.66; P = .01), advanced age (OR 1.85 per year; P = .02), chronic kidney disease (OR 1.70; P = .01), and atrial fibrillation (OR 2.02; P = .002) emerged as independent predictors of retreatment. Retreatment was significantly less often performed if primary CA was carried out at a specialized CHD center (P = .009) in patients with moderate to severe complexity heart disease. Women treated in specialist centers had a 1.6-fold reduced risk of undergoing retreatment (P = .01). CONCLUSION: CA for SVT is increasingly performed in ACHDs, especially for atrial flutter and atrial fibrillation. Patients with moderate and severe complexity congenital heart defects and female ACHDs benefit from upfront referral to specialized CHD centers for CA. Centralization of care for ACHD arrhythmias should thus be advocated.

Quantifying Left Atrial Size in the Context of Atrial Fibrillation Ablation: Which Echocardiographic Method Correlates to Outcome of Pulmonary Venous Isolation?

INTRODUCTION: Multiple studies have shown that left atrial (LA) enlargement is a strong predictor of poor outcome after catheter ablation of atrial fibrillation (AF). LA size is commonly approximated as the diameter in the parasternal long axis. It remains unknown whether more precise echocardiographic measurements of LA size allow for better correlation with outcome after pulmonary vein isolation (PVI). METHODS AND RESULTS: We performed a retrospective study of 131 consecutive patients (43 females, 60% paroxysmal AF, mean CHA2DS2-Vasc score 1.6, mean age 61 ± 12 years) referred for PVI. Measurements of the LA were carried out by a single observer in transthoracic echocardiograms (TTE) performed prior to ablation. We calculated diameter of the LA in the parasternal long axis (PLAX), LA area in the 2- as well as 4-Chamber (CH) view. LA volume was computed using the disc summation technique (LAV) and indexed to body surface area (LAVI). Procedural and follow-up data were gathered from a prospective AF database. Ablation was performed exclusively using the second generation cryoballoon by the same operators. Follow-up visits at 3, 6 and 12 months showed freedom from AF in 76%, 73% and 73% respectively. Mean values of LA calculations were LAPLAX: 37.9 mm ± 6.3 mm, 2CH area: 22.5 cm2 ± 6.7 cm2, 4CH area: 21.4 cm2 ± 5.5 cm2, LAV: 73.7 mL ± 26.1 mL and LAVI: 36.2 mL/m2 ± 12.7 mL/m2, respectively. C statistic revealed the best concordance of LAVI with outcome after 12 months (C = 0.67), LAV also exhibited a satisfactory value (C = 0.61) in comparison to surfaces in 2CH (C = 0.59) and 4CH (C = 0.57). PLAX showed the worst correlation (C = 0.51). Additionally, different binary logistic regression models identified three independent predictors of AF outcome after cryoballoon PVI: gender (OR = 0.95 per year; p = 0.01); LAV (OR = 1.3/10mL; p = 0.02) and LAVI (OR = 1.58/10 mL/m2; p = 0.02). In all models, PLAX and area measurements were not predictive. CONCLUSIONS: Our data add further to evidence that LA size lends itself well as a predictor of PVI outcome. LAVI and LAV were independently predictive of rhythm outcome after PVI. This did not hold true for more commonly used measurements, such as PLAX diameter and surfaces of the LA, irrespective of the view chosen.