Automated three-dimensional activation versus conventional mapping for catheter ablation of atrial tachycardia - A prospective randomized trial.

Background: The automated NavX Ensite Precision latency-map (LM) algorithm aims to identify atrial tachycardia (AT) mechanisms. However, data on a direct comparison of this algorithm with conventional mapping are scarce. Methods: Patients scheduled for AT ablation were randomized to mapping with the LM- algorithm (LM group) or to conventional mapping (conventional only group: ConvO), using entrainment and local activation mapping techniques. Several outcomes were exploratively analyzed. Primary endpoint was intraprocedural AT Termination. If AT termination with only automated 3D-Mapping failed, additional conventional methods were applied (conversion). Results: A total of 63 patients (mean 67 years, 34 % female) were enrolled. In the LM group (n = 31), the correct AT mechanism was identified in 14 patients (45 %) using the algorithm alone compared to 30 patients (94 %) with conventional methods. Time to termination of the first AT was not different between groups (LM group 34 ± 20 vs. ConvO 43.1 ± 28.3 min; p = 0.2). However, when AT termination did not occur with LM algorithm, time to termination prolonged significantly (65 ± 35 min; p = 0.01). After applying conventional methods (conversion), procedural termination rates did not differ between LM group (90 %) vs. ConvO (94 %) (p = 0.3). During a follow-up time of 20 ± 9 months, no differences were observed in clinical outcomes. Conclusion: In this small prospective, randomized study, the use of the LM algorithm alone may lead to AT termination, but less accurate than conventional methods.

Prevalence of STIs and people's satisfaction in a general population STI testing site in Bern, Switzerland.

OBJECTIVES: Access to affordable STI testing for asymptomatic persons is important to reduce STI transmission. Our testing site offers easily accessible and affordable STI testing for the general population irrespective of symptoms. Here we report STI prevalence and motivational factors of attendance. METHODS: Between 2017 and 2019, all participants at our STI testing site at the University Hospital Bern, Switzerland, were interviewed with a computer-based self-completion questionnaire. Pooled (oral, genital and anal) swabs were tested for Chlamydia trachomatis, Neisseria gonorrhoeae and blood samples for syphilis and HIV. People's motivational factors to attend were assessed using a standardised questionnaire. RESULTS: 5402 individuals between 17 and 82 (median 33.5) years were included. Of those, 2550 (47.2%) were between 25 and 34 years old and 3133 were heterosexual (58%), with rising attendance over the years. One-third attended because of a new sexual relationship, and one-third reported condomless sex. Among all individuals, we found 191 (3.8%) new chlamydia infections (89/191 in females and 101/191 in males) and 54 (1.1%) gonorrhoea infections (44/54 in males). In addition, 52/5125 tested individuals (0.8%) had syphilis requiring treatment.The number of sexual partners, previous bacterial STIs and condomless sex were associated with having an STI. Four heterosexual individuals were newly diagnosed with HIV. People rated a low threshold offer (through online booking or telephone) and personal counselling as most important factors to attend the service. CONCLUSION: We found many asymptomatic bacterial STIs requiring treatment. Offering easily accessible STI testing and counselling proved successful as shown by increasing rates of attendance and high levels of satisfaction.

Durable pulmonary vein isolation but not complex substrate ablation determines the type of arrhythmia recurrence after persistent atrial fibrillation ablation.

BACKGROUND: Complex ablation for persistent atrial fibrillation (AF) aims to modify the arrhythmogenic substrates to become incapable to perpetuate the arrhythmia. Ablation-associated determinants of atrial tachycardia (AT) rather than AF recurrences are unknown. The aim of the study was to evaluate the association between the type of arrhythmia recurrence and electrophysiological findings during redo procedures. METHODS: A total number of 384 consecutive patients with persistent AF underwent complex ablation consisting of PV isolation (PVI), biatrial electrogram-guided ablation, and linear ablation with the desired procedural endpoint of AF termination. Electrophysiological findings during redo procedures and its relation to AR type are the subject of this study. RESULTS: Overall, 177 (46%) patients underwent a second procedure. Patients with AT recurrences had significantly more often persistent PVI (47 vs. 25%; P = 0.002). Moreover, a higher number of recovered PVs were associated with AF recurrence (3 PVs recovered, AF = 16.1% vs. AT = 5.2%; P = 0.02; 4 PVs recovered, AF = 18.5% vs. AT = 6.3%; P = 0.01), regardless of the extent of substrate ablation during the first procedure. CONCLUSIONS: Durable PV isolation but not the extent of atrial substrate ablation determines the type of arrhythmia recurrence. Thus, the PVs may represent dominant perpetuators (and not only triggers) of persistent AF even in the presence of a significantly modified atrial substrate.

The Swiss STAR trial - an evaluation of target groups for sexually transmitted infection screening in the sub-sample of men.

OBJECTIVES: In Switzerland, universal health insurance does not cover any routine testing for sexually transmitted infections (STIs), not even in individuals at high risk, and extra-genital swabbing is not standard of care. We determined the prevalence and incidence of human immunodeficiency virus (HIV), viral hepatitis and non-viral STIs in a multicentre prospective observational cohort of multi-partner men who have sex with men (MSM) and other men. MATERIALS AND METHODS: Between January 2016 and June 2017, we offered free STI testing to all men with multiple  sexual partners (three or more in the previous 12 months), with follow-up examinations every 6 months. We used multiplex polymerase chain-reaction testing (for Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma genitalium) on pooled swabs (pharynx, urethra/vagina, anus), and antibody tests for HIV and Treponema pallidum at every visit, and for hepatitis B/C at baseline. RESULTS: We screened 779 multi-partner MSM and 92 other men. Previously undiagnosed HIV was found in 0.5% vs 0.0%, respectively and T. pallidum antibodies in 15.3% vs 1.1%. STIs requiring antibiotic treatment comprised: active syphilis 1.7% vs 0.0%; N. gonorrhoeae 10.3% vs 0.0%; C. trachomatis 8.7% vs 1.1%. One in four MSM versus 1 in 100 other multi-partner men had any of these three STIs at baseline. 10.4% vs 1.3% had a history of hepatitis B, 31.9% vs 47.3% had no immunity (HBs-AB <10 IU/l). Ten MSM had HCV antibodies (1.4%), with 8 out of the 10 being MSM with HIV; HCV seroprevalence was 0.3% among HIV-negative MSM. In MSM, incidence of the three bacterial STIs was 25.5 per year over 333 person years of follow-up, HIV incidence was 0.3%. Non-condom-use (in the last 3 months) for anal/vaginal sex was not associated with STIs. Independent risk factors were sex with men (adjusted odds ratio [aOR] 16.4) and the number of sexual partners (aOR 2.3 for >20). CONCLUSION: Among MSM, but not among other multi-partner men, STIs, mostly asymptomatic, are common. Given the high risk of onward transmission, low-cost or free routine screening of multi-partner MSM is a public health priority.

Predictors of successful complex catheter ablation for persistent atrial fibrillation despite failure of targeted procedural arrhythmia termination.

INTRODUCTION: Procedural atrial fibrillation (AF) termination is considered as a predictor of long-term success after catheter ablation for persistent AF (persAF). However, some patients remain free of arrhythmia recurrences despite failure to achieve AF termination. The objective of this study was to assess long-term outcome and prognostic factors in patients undergoing complex ablation without procedural AF termination. METHODS AND RESULTS: This study comprised 419 patients (63.8 ± 10.2 years, 63.4% male) undergoing complex ablation for persAF. Patients without procedural AF termination (n = 137, 64.2 ± 9.7 years, 63.5% male) were categorized into patients who remained in sinus rhythm (SR) in long-term outcome (SR-group) and patients with recurrence of AF or atrial tachycardia (AT) (AR-group). During a follow-up (FU) of 19.6 ± 14.6 months, the SR-group consisted of 65 (47.5%) and the AR-group of 69 (50.4%) patients. Three patients (2.2%) were lost to FU. Left atrial appendage (LAA) flow velocity and left atrium volume index (LAVI) could be identified as predictors for long-term success. LAA flow velocity and baseline AF cycle length (AFCL) were significantly associated with the type of arrhythmia recurrence (AF vs AT), ie, higher values of both are predictive for AT rather than AF recurrences. Patients with a LAVI < 34.4 mL/m² and significant AFCL increase during the ablation procedure had rather AT than AF recurrences. CONCLUSION: Patients with an arrhythmia-free outcome despite failure of procedural AF termination during complex ablation for persAF are characterized by specific morphological and functional properties that are easy to obtain.

Risk for life-threatening arrhythmia in newly diagnosed peripartum cardiomyopathy with low ejection fraction: a German multi-centre analysis.

INTRODUCTION: Peripartum cardiomyopathy (PPCM) is a rare cardiomyopathy characterized by an acute reduction in left ventricular ejection fraction (LVEF). Sudden deaths during the course of PPCM are reported to be elevated, the underlying mechanisms remains unknown. The aim of the present multi-centre study was to evaluate the arrhythmia burden in a multi-centre approach in patients with PPCM using a wearable cardioverter/defibrillator (WCD). METHODS AND RESULTS: Forty-nine patients from 16 German centres with newly diagnosed PPCM and LVEF ≤35% receiving a WCD were included in this retrospective analysis. Mean follow-up was 15 ± 10 months. At diagnosis, mean age was 33 ± 5 years, parity was 2.1 ± 1.6, LVEF was 21 ± 7%, NYHA functional class was 3.4 ± 0.7. Mean wear time was 120 ± 106 days, mean wear time per day was 21.4 ± 3.3 h. Six (12%) patients presented eight ventricular tachyarrhythmias during WCD period: five episodes of VF, two sustained ventricular tachycardia (VT) and one non-sustained VT occurred. CONCLUSION: This multicentre study underpins the elevated risk for ventricular tachyarrhythmias in patients with newly diagnosed PPCM and reduced LVEF. A WCD should be considered for 3-6 months in these patients to prevent sudden cardiac death from ventricular tachyarrhythmias.

Cardiac arrhythmias in patients with Danon disease.

AIMS: Different cardiac arrhythmias have been suggested to be associated with Danon disease, e.g. Wolff-Parkinson-White syndrome. However, a systematic electrophysiological investigation of patients with Danon disease is lacking thus far. METHODS AND RESULTS: Seven patients with Danon disease (4 males, 35.8 ± 10.8 years; 3 females, 51.3 ± 19.9 years) from 3 different families were studied. In all patients, the presence of Danon disease was confirmed by western blot of biopsy material or genetic testing. The patients were characterized by 12-lead electrocardiogram (ECG), Holter ECG, echocardiography, and serial implantable cardioverter defibrillator (ICD) interrogations (in ICD recipients). All male patients underwent electrophysiological investigation (EP study). Asymptomatic ventricular tachyarrhythmias were documented in six of the seven patients. Moreover, 5 of the 7 patients suffered from atrial fibrillation (AF), with 1 of them experiencing thromboembolic stroke at the age of 30 years. In male patients, the initial QRS complex was characterized by a slurring upstroke and shortened PQ interval mimicking ventricular pre-excitation. One male patient showed initial QRS complex slurring with prolonged PR interval. However, the presence of an accessory pathway was excluded by an EP study in all patients. In female patients, initial QRS complex slurring was significantly less distinct. In four patients, ICD implantation was performed for primary prevention of sudden cardiac death. However, sustained ventricular arrhythmias were not documented in any of the patients. CONCLUSIONS: The present study indicates that the distinct surface ECG pattern in Danon disease is not associated with ventricular pre-excitation. Atrial fibrillation is frequently observed in these patients and may be associated with thromboembolic events in the young, while sustained ventricular arrhythmias occur less frequently than previously reported.

Systematic ajmaline challenge in patients with long QT 3 syndrome caused by the most common mutation: a multicentre study.

AIMS: Overlap syndromes of long QT 3 syndrome (LQT3) and the Brugada syndrome (BrS) have been reported. Identification of patients with an overlapping phenotype is crucial before initiation of Class I antiarrhythmic drugs for LQT3. Aim of the present study was to elucidate the yield of ajmaline challenge in unmasking the Brugada phenotype in patients with LQT3 caused by the most common mutation, SCN5A-E1784K. METHODS AND RESULTS: Consecutive families in tertiary referral centres diagnosed with LQT3 caused by SCN5A-E1784K were included in the study. Besides routine clinical work-up, ajmaline challenge was performed after informed consent. A total of 23 subjects (11 female, mean age 27 ± 14 years) from 4 unrelated families with a family history of sudden cardiac death and familial diagnosis of the SCN5A-E1784K mutation underwent ajmaline challenge and genetic testing. Sixteen subjects (9 female) were found to be heterozygous carriers of SCN5A-E1784K. Ajmaline challenge was positive in 12 out of the 16 (75%) mutation carriers, but negative in all non-carriers. Following ajmaline, a significant shortening of the rate-corrected JT (JTc) interval was observed in mutation carriers. The baseline JTc interval was significantly longer in mutation carriers with a positive ajmaline challenge compared with those with a negative one. CONCLUSION: Overlap of LQT3 and BrS in patients carrying the most common mutation is high. Therefore, ajmaline challenge represents an important step to rule out potential BrS overlap in these patients before starting sodium channel blockers for the beneficial effect of QT shortening in LQT3.

Rationale and design of the RE-LATED AF--AFNET 7 trial: REsolution of Left atrial-Appendage Thrombus--Effects of Dabigatran in patients with Atrial Fibrillation.

BACKGROUND: Dabigatran etexilate, a direct thrombin inhibitor and non-vitamin K antagonist oral anticoagulant (NOAC), has been shown to effectively prevent thromboembolic events in patients with non-valvular atrial fibrillation (AF). However, there is a paucity of data on the antithrombotic efficacy and safety of dabigatran in the resolution of left atrial appendage (LAA) thrombi in AF patients. OBJECTIVE: The primary objective of the RE-LATED AF trial is to assess whether dabigatran results in a faster complete LAA thrombus resolution as compared to vitamin K antagonist phenprocoumon. Secondary objectives are to assess the impact of dabigatran on complete LAA thrombus resolution rate within 6 weeks of treatment and change in LAA thrombus volume under treatment. Furthermore, this study aims to assess and compare safety and tolerability of dabigatran vs. phenprocoumon. METHODS: The study is designed as a prospective, randomized, open-label, controlled, explorative, blinded endpoint (PROBE) trial. Patients with AF and left atrial appendage thrombus confirmed by transoesophageal echocardiography (TEE) will be randomized to receive either dabigatran (150 mg bid) or phenprocoumon (INR 2-3) for the resolution of LAA thrombus formation for at least 21 days. Thrombus resolution will be determined by TEE 3 weeks after treatment initiation and subsequently at weeks 4 and 6, if the LAA thrombus has not been resolved before. A total of 110 patients are planned to be randomized. CONCLUSION: This is the first prospective, multicentre, randomized controlled clinical trial investigating safety and efficacy of a NOAC for the resolution of LAA thrombi in patients with non-valvular AF.

Primary Persistent Atrial Fibrillation: A Distinct Arrhythmia Subentity of an Ablation Population.

INTRODUCTION: Persistent atrial fibrillation (persAF) can occur either as a sustained arrhythmia that has progressed from initially paroxysmal AF or as primary persAF without a history of any spontaneously terminated episode. There is a paucity of data differentiating between the 2 different persAF entities. Thus, we prospectively evaluated baseline characteristics, electrophysiological features, and ablation outcome in these 2 patient cohorts. METHODS AND RESULTS: A total number of 154 consecutive persAF patients (63 ± 10 years, f = 42, longstanding persAF = 60) were characterized in terms of having primary persAF (P-persAF group) or persAF that secondarily progressed from paroxysmal AF (S-persAF group). All patients underwent de novo catheter ablation using the stepwise approach. PersAF entities were characterized by detailed patient history, sequential Holter monitoring, and reports of documented modes of AF conversion, respectively. The P-persAF group had a higher number of young patients (<50 years), a shorter AF history, and a higher number of congestive heart failure. The HATCH score did not differ between the groups. Procedural AF termination rate was significantly higher in S-persAF than in P-persAF patients (n = 55 [81%] vs. n = 58 [68%], P = 0.043). At 1-year follow-up, the arrhythmia-free survival after a single procedure was significantly lower in patients with P-persAF (26% vs. 43%, P = 0.016). Categorization to P-persAF was the strongest independent predictor of arrhythmia recurrence. CONCLUSIONS: P-persAF seems to be a specific arrhythmia entity that is associated with a lower AF-termination rate and a worse outcome after catheter ablation as compared to S-persAF.

[Surface ECG characteristics of right and left atrial flutter]. / Oberflächen-EKG-Charakteristika von rechts- und linksatrialem Vorhofflattern.

INTRODUCTION: Atrial tachycardia in virtually all areas of both atria has become more important in the clinical management of patients with previous complex atrial fibrillation ablation. Accurate interpretation of surface electrocardiogram (ECG) characteristics is of paramount importance to localize the origin of atrial tachycardia, particularly for planning interventional treatment. This article highlights the ECG features of different types of right and left atrial tachycardia. DEFINITION: Typical right atrial flutter through the cavotricuspid isthmus conducts septally in a cranial direction and demonstrates sawtooth-like flutter waves which start negative in II, III and aVF and then show a steep slope upwards to the isoelectric line. The flutter rate typically ranges between 240-250 beats/min. In contrast, right atrial flutter in a clockwise rotation, flutter around the vena cava inferior or superior and around a scar (e.g. after cardiac surgery) show positive or biphasic flutter waves (lower or upper loop reentry). Left atrial flutter waves (e.g. around the mitral valve or around the pulmonary veins) are very heterogeneous and are typically positive in V1 as the left atrium is located in the posterior mediastinum. CONCLUSION: Specific knowledge of flutter wave morphology in surface ECG facilitates planning and performance of the ablation strategy.

Arrhythmia Termination Versus Elimination of Dormant Pulmonary Vein Conduction as a Procedural End Point of Catheter Ablation for Paroxysmal Atrial Fibrillation: A Prospective Randomized Trial.

BACKGROUND: Pulmonary vein isolation (PVI) is still associated with a substantial number of arrhythmia recurrences in paroxysmal atrial fibrillation (AF). This prospective, randomized study aimed to compare 2 different procedural strategies. METHODS AND RESULTS: A total of 152 patients undergoing de novo ablation for paroxysmal AF were randomized to 2 different treatment arms. The procedure in group A consisted of PVI exclusively. In this group, all isolated PVs were challenged with adenosine to reveal and ablate dormant conduction. In group B, PVI was performed with the patient either in spontaneous or in induced AF. If AF did not terminate with PVI, ablation was continued by targeting extra-PV AF sources with the desired procedural end point of termination to sinus rhythm. Primary study end point was freedom from arrhythmia during 1-year follow-up. In group A, adenosine provoked dormant conduction in 31 (41%) patients with a mean of 1.6±0.8 transiently recovered PVs per patient. Termination of AF during PVI was observed in 31 (65%) patients, whereas AF persisted afterward in 17 (35%) patients. AF termination occurred in 13 (76%) patients by AF source ablation. After 1-year follow-up, significantly more group B patients were free of arrhythmia recurrences (87 versus 68%; P=0.006). During redo ablation, the rate of PV reconduction did not differ between both groups (group A: 55% versus group B: 61%; P=0.25). CONCLUSIONS: Elimination of extra-PV AF sources after PVI is superior to sole PV isolation with the adjunct of abolishing potential dormant conduction. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02238392.

The Incidence of Audible Steam Pops Is Increased and Unpredictable With the ThermoCool® Surround Flow Catheter During Left Atrial Catheter Ablation: A Prospective Observational Study.

INTRODUCTION: Open irrigated radiofrequency (RF) ablation catheters with a porous tip (56 holes, TC-SF) permit delivering RF energy in a temperature-controlled mode without temperature rise. This prospective observational study investigated the association of different catheter parameters on the occurrence of audible steam pops during left atrial (LA) ablation. METHODS AND RESULTS: A total of 226 patients underwent TC-SF catheter ablation for atrial fibrillation. RF power delivery, impedance and catheter tip temperature were continually recorded throughout the ablation. Pulmonary vein isolation was performed with a maximum of 27 W and LA electrogram-guided or linear ablation with a maximum of 30 W. A total of 59 audible steam pops occurred, 2 of them resulting in pericardial tamponade. In the initial 89 patients, with an irrigation flow rate of 10 mL/min, 18 steam pops with one tamponade occurred in 12 (14%) patients. Subsequently, the irrigation flow rate was increased to 20 mL/min in the following 137 patients, resulting in the occurrence of 41 steam pops including one case of tamponade in a total of 30 (22%) patients. The maximal power was significantly higher in RF applications associated with a pop than those that did not. In only 12 (20%) steam pops, a significant impedance change occurred immediately before pop occurrence (4 [7%] impedance rise >10 ohm, 8 [13%] impedance drop >15 ohm). CONCLUSIONS: The TC-SF catheter does not provide sufficient feedback from the ablated tissue to prevent steam popping.

Body surface potential mapping for mapping and treatment of persistent atrial fibrillation.

Techniques facilitating individual mapping and ablation of arrhythmogenic substrates are desired to enhance our understanding of persistent atrial fibrillation (persAF) mechanisms as a prerequisite to increasing the success rates of single procedure persAF catheter ablation. The technique of body surface potential mapping (BSM) involves the use of multiple electrodes to collect the potentials over a large body surface area and, with the use of a computed tomography scan, it facilitates their correlation to a 3D model of the atrial structures. During AF,the visualization and localization of AF driver activity, both reentrant and focal wavefronts, is possible with this technique. The ECVUE system from CardioInsight was examined for this indication in clinical studies and showed a termination rate of persAF of 63 % in a large multicenter trial (AFACART) with a promising low recurrence rate during follow-up. From our initial experience, the system appears to be effective in persAF patients who have continuous AF for less than 1 year. However, the utility of the system for highly challenging cases like long-standing persistent AF and patients with very short AF cycle length remains to be explored. Further studies are needed to confirm these data and answer the multitude of open questions in this field.

Reduction of ICD shock burden by eliminating back-up pacing induced ventricular tachyarrhythmias.

INTRODUCTION: Implantable cardioverter defibrillators (ICD) may have the capacity to provoke or worsen ventricular tachyarrhythmias (VT). It has been reported that ICD shocks by itself can increase mortality. This study aimed to determine the role of back-up pacing-induced VT (PIT) in the overall ICD shock burden by avoiding pause-related ventricular back-up pacing. METHODS AND RESULTS: A population of 550 single-chamber ICD patients was studied. Of them, 17 (3%, 69 ± 16 years, 14 male) patients had documented episodes of PIT. A total of 431 VT episodes were documented including 89 (21%) due to PIT. In 3 patients, VT events were exclusively PITs. After ≥2 documented PITs, the pacing output for VVI pacing was set to a subthreshold level resulting in noncapturable ventricular back-up pacing. All other device parameters remained unchanged to prove a potential proarrhythmic effect of pause related back-up pacing. During a follow-up of 99 ± 39 months after reducing the pacing output to a subthreshold level, no further episodes of PIT were observed (P < 0.001). Moreover, with the prevention of PITs, the ICD shock burden decreased significantly (pre: 150 vs. post: 18, P < 0.001). However, a single event of pause-induced VT occurred due to missing back-up pacing. CONCLUSIONS: PIT is a frequent mechanism of VTs in ICD patients resulting in a substantially increased shock burden. Elimination of pause-related back-up pacing by subthreshold pacing output effectively abolishes PIT and thus significantly reduces ICD shock burden.