Predictors of low-voltage zones in patients with persistent atrial fibrillation eligible for catheter ablation: An observational study.

INTRODUCTION: The presence of low-voltage zones (LVZs) in the left atrium (LA) is associated with the recurrence of atrial fibrillation (AF) following pulmonary vein isolation (PVI). However, there is variability and conflict in the data regarding predictors of LVZs as reported in previous studies. The objective of this study was to identify predictors for the presence of LVZs in a cohort of patients with persistent AF. METHODS: The study prospectively enrolled 439 patients with persistent AF who were scheduled for ablation. Voltage map of the LA was collected using a multipolar catheter. An LVZ was defined as an area of ≥3 cm2 exhibiting a peak-to-peak bipolar voltage of <0.5 mV. RESULTS: The mean age of the cohort was 65.3 ± 8.6 years and 26.4% were female. Additionally, 25.7% had significant LVZs, most frequently located in the anterior wall of the LA. Multivariable analysis identified the following independent predictors for LVZ: advanced age (OR [odds ratio] = 1.08, 95% CI [confidence interval] = 1.03-1.13, p = .002); female sex (OR = 4.83, 95% CI = 2.66-8.76, p < .001); coronary artery disease (CAD) (OR = 3.20, 95% CI = 1.32-7.77, p = .01) and enlarged LA diameter (OR = 1.10, 95% CI = 1.04-1.17, p = .001). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the final model was 0.829. CONCLUSION: Approximately 25% of the patients with persistent AF had LVZs. Advanced age, female sex, CAD, and a larger LA were independent predictors for LVZs with the model demonstrating a very good AUC for the ROC curve. These findings hold the potential to be used to tailor the ablation procedure for the individual patient.

Risk assessment in patients with symptomatic and asymptomatic pre-excitation.

AIMS: Controversy remains as to whether the exercise stress test (EST) is sufficient for risk evaluation in patients with pre-excitation. This study aims to clarify the usefulness of EST in risk stratification in both asymptomatic and symptomatic patients presenting with pre-excitation. METHODS AND RESULTS: This prospective study includes consecutive asymptomatic and symptomatic patients with pre-excitation referred for risk assessment. All participants performed an incremental EST (bicycle) prior to an electrophysiology study (EPS). Primary data from the EST included loss of pre-excitation during exercise, and primary data from the EPS included the measurement of accessory pathway effective refractory period (APERP), shortest pre-excited RR interval (SPERRI), and inducible arrhythmia with the use of a beta-adrenergic receptor agonist if deemed necessary. One hundred and sixty-four patients (59 asymptomatic, 105 symptomatic) completed an EST and EPS. Forty-five patients (27%) demonstrated low-risk findings on EST, of which 19 were asymptomatic and 26 were symptomatic. Six patients with low-risk EST findings had SPERRI/APERP ≤ 250 ms at EPS, and two of them were asymptomatic. The sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of low-risk EST for excluding patients with SPERRI/APERP ≤ 250 ms were 40, 91, 87, 51, and 60%, respectively. The number of patients with inducible arrhythmia at EPS was similar in the asymptomatic (36, 69%) and symptomatic (73, 61%) groups. CONCLUSION: Sudden loss of pre-excitation during EST has a low NPV in excluding high-risk APs. The EPS with the use of isoproterenol should be considered to accurately assess the risk of patients with pre-excitation regardless of symptoms (ClinicalTrials.gov Identifier: NCT03301935).

Randomized Ablation-Based Rhythm-Control Versus Rate-Control Trial in Patients With Heart Failure and Atrial Fibrillation: Results from the RAFT-AF trial.

BACKGROUND: Atrial fibrillation (AF) and heart failure (HF) frequently coexist and can be challenging to treat. Pharmacologically based rhythm control of AF has not proven to be superior to rate control. Ablation-based rhythm control was compared with rate control to evaluate if clinical outcomes in patients with HF and AF could be improved. METHODS: This was a multicenter, open-label trial with blinded outcome evaluation using a central adjudication committee. Patients with high-burden paroxysmal (>4 episodes in 6 months) or persistent (duration <3 years) AF, New York Heart Association class II to III HF, and elevated NT-proBNP (N-terminal pro brain natriuretic peptide) were randomly assigned to ablation-based rhythm control or rate control. The primary outcome was a composite of all-cause mortality and all HF events, with a minimum follow-up of 2 years. Secondary outcomes included left ventricular ejection fraction, 6-minute walk test, and NT-proBNP. Quality of life was measured using the Minnesota Living With Heart Failure Questionnaire and the AF Effect on Quality of Life. The primary analysis was time-to-event using Cox proportional hazards modeling. The trial was stopped early because of a determination of apparent futility by the Data Safety Monitoring Committee. RESULTS: From December 1, 2011, to January 20, 2018, 411 patients were randomly assigned to ablation-based rhythm control (n=214) or rate control (n=197). The primary outcome occurred in 50 (23.4%) patients in the ablation-based rhythm-control group and 64 (32.5%) patients in the rate-control group (hazard ratio, 0.71 [95% CI, 0.49-1.03]; P=0.066). Left ventricular ejection fraction increased in the ablation-based group (10.1±1.2% versus 3.8±1.2%, P=0.017), 6-minute walk distance improved (44.9±9.1 m versus 27.5±9.7 m, P=0.025), and NT-proBNP demonstrated a decrease (mean change -77.1% versus -39.2%, P<0.0001). Minnesota Living With Heart Failure Questionnaire demonstrated greater improvement in the ablation-based rhythm-control group (least-squares mean difference of -5.4 [95% CI, -10.5 to -0.3]; P=0.0036), as did the AF Effect on Quality of Life score (least-squares mean difference of 6.2 [95% CI, 1.7-10.7]; P=0.0005). Serious adverse events were observed in 50% of patients in both treatment groups. CONCLUSIONS: In patients with high-burden AF and HF, there was no statistical difference in all-cause mortality or HF events with ablation-based rhythm control versus rate control; however, there was a nonsignificant trend for improved outcomes with ablation-based rhythm control over rate control. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01420393.

Elite female endurance athletes are at increased risk of atrial fibrillation compared to the general population: a matched cohort study.

OBJECTIVE: Previous studies have found that endurance sport activity is associated with an increased risk of atrial fibrillation (AF) in men. However, it remains unclear whether endurance sports also influence the risk of AF in women. We aimed to examine whether participation in endurance sports may affect the risk of AF in female athletes. METHODS: We conducted a retrospective matched cohort study of top Swedish female endurance athletes (n=228) and reference individuals (n=1368) from the general population using the Swedish Total Population Register individually matched with a 6:1 ratio of female athletes. The athlete cohort was created by combining all Swedish women who ran the Stockholm Marathon faster than 3 hours 15 min in any of the races between 1979 and 1991, all women competing in the Swedish athletic national championships in the 10 000 metre race, and the top-ranked Swedish cyclists during the same period. We used the National Patient Register to determine whether the participants were diagnosed with AF. RESULTS: Mean age at the start of follow-up was 32 (SD±8.5) years. During follow-up (mean 28.8 years; SD±4.4), 33 cases of AF were diagnosed, including 10 (4.4%) among athletes and 23 (1.7%) among references. The HR for female athletes compared with the reference population was 2.56 (95% CI 1.22 to 5.37) in the univariable model and 3.67 (95% CI 1.71 to 7.87) after adjustment for hypertension. CONCLUSION: Elite female endurance athletes are at increased risk of AF than the general population.

Feasibility of a novel algorithm for automated reconstruction of the left atrial anatomy based on intracardiac echocardiography.

BACKGROUND: Intracardiac echocardiography (ICE) is frequently used to guide electrophysiology procedures. The novel automated algorithm Cartosoundfam is a model-based algorithm which reconstructs a 3D anatomy of the left atrium (LA) based on a set of 2D intracardiac echocardiography (ICE) frames, without the need to manually annotate ultrasound (US) contours. OBJECTIVE: The aim of this study was to determine the feasibility of the Cartosoundfam module in routine clinical setting. METHODS: We included 16 patients undergoing LA mapping/catheter ablation. Two-dimensional US frames were acquired from the right atrium (RA) and the right ventricular outflow tract. The Cartosoundfam map was validated in two steps: (1) identification of anatomical structures (pulmonary veins [PV] and LA body and appendage) by alignment of the ablation catheter to the automated map; and (2) analysis of the automated lesion tags (Visitag) location in relation to the PV antrum of the Cartosoundfam map in nine patients with paroxysmal atrial fibrillation (AF) undergoing first time pulmonary vein isolation (PVI). RESULTS: Mean 2D US frames per patient were 29 ± 6 and acquisition time was 16 ± 4 min. All anatomical structures were correctly identified in all patients (step 1). In the step 2 validation, the median distance to the map was 2.0 (IQR: 2.4) mm and the majority of the Visitags were classified as satisfactory (69%) but all PV segments had some Visitags classified as unsatisfactory. CONCLUSION: The automated ICE-based algorithm correctly identified the LA anatomical structures in all patients with a 69% anatomical accuracy of the Visitags alignments to the PV antrum segments.

Women with atrial fibrillation undergoing pulmonary vein isolation are more symptomatic but improve more in health-related quality of life and symptom burden than men.

Gender differences in symptoms and perceived health-related quality of life (HRQOL) in patients with atrial fibrillation (AF) referred to pulmonary vein isolation (PVI) have been reported previously. Women experience a lower HRQOL, faster heart rate, and more symptoms such as palpitation and dyspnea than men. Furthermore, they experience worse physical functioning independently of other heart diseases or age. This study evaluates referral patterns and symptoms, morbidity, functional impairment, and HRQOL from a gender perspective in patients with AF before and 6 months after PVI. The study includes 242 patients (121 men), mean age 62 ± 9 years, referred for PVI. Symptoms were assessed with the Symptom Checklist: Frequency and Severity (SCL), HRQOL with Short Form 36 (SF-36), and the functional impairment with Sickness Impact Profile (SIP). The patients' own experiences of the referral process and history of their disease were evaluated with a supplementary questionnaire. The results showed that women improved more than men in HRQOL, SIP, and SCL 6 months post PVI. There were no sex differences in proportion of paroxysmal and persistent AF or ablation outcome. At baseline, women scored higher than men in both scales of the SCL (p < 0.001), scored lower in all components in SF-36, and scored higher in five categories of the SIP. Women were not more reluctant to accept referral for ablation when offered. The conclusion is that women with AF undergoing PVI are more symptomatic but also improve more in HRQOL and in symptom burden than men.

Low incidence of major complications after the first six hours post atrial fibrillation ablation: Is same-day discharge safe and feasible in most patients?

AIMS: This study evaluates the incidence of procedural complications related to catheter ablation of atrial fibrillation (AF) to assess the potential feasibility and safety of same-day discharge in a large cohort. METHODS: We performed an analysis of prospectively collected data of complications of all patients staying overnight after undergoing AF ablation between 2001 and 2020 at a tertiary center. Using medical records, we analyzed complications occurring intraprocedurally until 6 h postablation and between 6 h postablation and discharge the day after the ablation procedure. RESULTS: In 5414 AF ablations, we identified a total of 108 (2.0%) major complications occurring intraprocedural or before discharge. Most major complications occurred intraprocedurally or within 6 h after the procedure (n = 96, 1.8%). Twelve (0.2%) major complications occurred between 6 h Postablation and discharge. The most common of these major complications were congestive heart failure (n = 6) and transient ischemic attack (TIA, n = 4). During this time span, 61 (1.1%) minor complications occurred. Factors independently associated with major complications intraprocedurally and until discharge were body mass index (BMI) ≥ 30 kg/m2 (p = .009), significant valvular disease (p = .001), cardiomyopathy (p < .001), prior stroke or TIA (p = .014), first-time procedure versus repeat procedure (p = .013), cryoablation versus radiofrequency (p < .001), and procedure duration (p < .001). CONCLUSION: After AF ablation, very few complications occurred between 6 h postprocedure and discharge the next day. Therefore, same-day discharge is a safe option for a majority of patients.

Early recurrences of atrial tachyarrhythmias post pulmonary vein isolation.

AIMS: To investigate the significance of early recurrence (ER) of atrial tachyarrhythmias after pulmonary vein isolation (PVI) on the development of late recurrence (LR) and to redefine the blanking period during which an ER is considered nonspecific. METHODS: Data of 713 patients undergoing their first PVI for paroxysmal or persistent atrial fibrillation between January 2012 and December 2017 were included. All patients were followed-up for 12 months according to clinical and outpatient routine and were screened for any atrial tachyarrhythmia lasting >30 seconds occurring during the first 3 months postablation (ER) and after the 3 months blanking period (LR). RESULTS: Patients with ER compared to those without ER had significantly more LR (74.5% vs 16.5% vs, P < .001). The occurrence of ER during the first, second and third months showed increasing LR rates of 35.2%, 67.9%, and 94.8%, respectively (P < .001). Receiver operator characteristic analysis revealed a blanking period of 46 days with the highest sensitivity (68.1%) and specificity (96.5%). Later timing and longer time span of ER were independent predictors for LR in multivariable analysis. CONCLUSION: ER is a strong predictor for LR. Our study advocates a shortening of the post-PVI blanking period followed by a "gray zone" up to 3 months where individualized therapeutic decisions based on additional risk factors should be considered. We suggest that the ER time span might serve as such a predictor identifying patients at the highest risk for LR.

Long-term outcome of patients with invasive electrophysiology procedure-related cardiac tamponade.

AIMS: Iatrogenic cardiac tamponades are a rare but dreaded complication of invasive electrophysiology procedures (EPs). Their long-term impact on clinical outcomes is unknown. This study analysed the risk of death or serious cardiovascular events in patients suffering from EP-related cardiac tamponade requiring pericardiocentesis during long-term follow-up. METHODS AND RESULTS: Out of 19 997 invasive EPs at the Karolinska University Hospital between January 1998 and September 2018, all patients with EP-related periprocedural cardiac tamponade were identified (n = 60) and matched (1:3 ratio) to a control group (n = 180). After a follow-up of 5 years, the composite primary endpoint - death from any cause, acute myocardial infarction, transitory ischaemic attack (TIA)/stroke, and hospitalization for heart failure - occurred in significantly more patients in the tamponade than in the control group [12 patients (20.0%) vs. 19 patients (10.6%); hazard ratio (HR) 2.53 (95% confidence interval, CI 1.15-5.58); P = 0.021]. This was mainly driven by a higher incidence of TIA/stroke in the tamponade than in the control group [HR 3.75 (95% CI 1.01-13.97); P = 0.049]. Death from any cause, acute myocardial infarction, and hospitalization for heart failure did not show a significant difference between the groups. Hospitalization for pericarditis occurred in significantly more patients in the tamponade than in the control group [HR 36.0 (95% CI 4.68-276.86); P = 0.001]. CONCLUSION: Patients with EP-related cardiac tamponade are at higher risk for cerebrovascular events during the first 2 weeks and hospitalization for pericarditis during the first months after index procedure. Despite the increased risk for early complications tamponade patients have a good long-term prognosis without increased risk for mortality or other serious cardiovascular events.

Chocolate consumption and risk of atrial fibrillation: Two cohort studies and a meta-analysis.

BACKGROUND: Chocolate consumption has been inconsistently associated with risk of atrial fibrillation (AF). We investigated the association between chocolate consumption and risk of AF in Swedish adults from two cohort studies and conducted a meta-analysis to summarize available evidence from cohort studies on this topic. METHODS: Our study population comprised 40,009 men from the Cohort of Swedish Men and 32,486 women from the Swedish Mammography Cohort. Incident AF cases were ascertained through linkage with the Swedish National Patient Register. Published cohort studies of chocolate consumption in relation to risk of AF were identified by a PubMed search through September 14, 2017. RESULTS: During a mean follow-up of 14.6 years, AF was diagnosed in 9978 Swedish men and women. Compared with non-consumers, the multivariable hazard ratio of AF for those in the highest category of chocolate consumption (≥3-4 servings/week) was 0.96 (95% CI 0.88-1.04). In a random-effects meta-analysis of 5 cohort studies, including 180,454 participants and 16,356 AF cases, the hazard ratios of AF were 0.97 (95% CI 0.94-1.01) per 2 servings/week increase in chocolate consumption and 0.96 (95% CI 0.90-1.03) for the highest versus lowest category of chocolate consumption. CONCLUSION: Available data provide no evidence of an association of chocolate consumption with risk of AF.

Atrio-ventricular junction ablation and pacemaker treatment: a comparison between men and women.

OBJECTIVES: To explore sex differences regarding indication for atrio-ventricular junction ablation (AVJ), choice of pacing system, complications to pacemaker treatment, long-term outcome, and cause of death after AVJ ablation. DESIGN: 700 patients who had undergone AVJ ablation between January 1990 and December 2010 were included. Data were retrieved from the patients´ medical records and the Swedish Pacemaker and Implantable Cardioverter-Defibrillator Registry. Information about admission to hospital and cause of death was retrieved from the National Board of Health and Welfare. RESULTS: Mean follow-up was 90 ± 64 months. Indication for AVJ ablation, choice of pacing system, and outcome after AVJ ablation differed between the sexes. The men had more often permanent atrial fibrillation, p = .0001, and a VVIR pacemaker or cardiac resynchronization therapy (CRT) implanted prior to ablation, p = .0001. Heart failure was present in 44% of the men vs. 28% of the women, p = .0001. LVEF decreased slightly in the whole cohort after the AVJ ablation. There were no sex differences in complication rates due to the pacemaker/ICD treatment, p = .3 or mortality due to AVJ ablation. CONCLUSION: In this long-term follow-up in patients with atrial fibrillation treated with AVJ ablation and pacing, indication, choice of pacing system, and morbidity differed but there were no sex differences regarding survival or primary cause of death found. The main factor influencing survival was age at the time of ablation. Women less often received treatment with ICD and/or CRT when indication was present compared with men.

Cryoablation of atrioventricular nodal re-entrant tachycardia: 7-year follow-up in 515 patients-confirmed safety but very late recurrences occur.

AIMS: Cryoablation is an alternative method to radiofrequency ablation for treatment of atrioventricular nodal re-entrant tachycardia (AVNRT). This study investigates the long-term safety and efficacy of cryoablation in AVNRT. METHODS AND RESULTS: We studied 515 consecutive patients (317 women, mean age 50 years, range 13-89 years) undergoing a first cryoablation for AVNRT between 2003 and 2008. Ablations were performed with a 6-mm Freezor Xtra catheter. Six patients were acute failures; 494 out of 509 (97%) primarily successfully ablated patients were followed up for a mean of 7.1 years (range 2-12 years). About 11% (54/494 patients) of patients had recurrences of the index arrhythmia. Time to recurrence varied from days to 9 years; 14 patients (3%) had recurrences later than 2 years, 8 patients (2%) later than 3 years, and 6 patients (2%) later than 4 years. Recurrence rate was higher in patients with slow-slow or fast-slow AVNRT (n = 24) compared with the common slow-fast variant (25 vs. 10%; P = 0.04). Recurrence rate was not higher in patients with residual slow pathway conduction (jump with or without echo beat, n = 199, 39%). Transient atrioventricular (AV) block of the first-, second-, or third-degree during ablation was observed in 45 patients but had no impact on the risk of AVNRT recurrence. No late AV block occurred. Single vs. multiple applications or total amount of cryoenergy delivered did not differ between patients with and without recurrences. CONCLUSION: Cryoablation in AVNRT is safe with a long-term efficacy of 88%; however, very late recurrences occur.

Safety of fluoroscopy-guided transseptal approach for ablation of left-sided arrhythmias.

AIMS: The transseptal approach is used for left atrial access during the ablation of atrial fibrillation (AF) and other left-sided arrhythmia substrates. Transseptal puncture (TP) is commonly performed with fluoroscopic guidance, contrast injection, and pressure monitoring. In many centres, additional techniques [intracardiac echocardiography (ICE), transoesophageal echocardiography (TEE), radiofrequency needle] are used to facilitate TP but its use adds costs. In this retrospective study, we studied the safety and complication rate when TP was routinely done with fluoroscopic guidance, contrast injection, and pressure monitoring using ICE or TEE only in selected cases. METHODS AND RESULTS: This study analysed 4690 consecutive TP performed between 2000 and 2015: 3408 (72.6%) were ablation of AF, left-sided atrial flutter, or left-sided atrial tachycardia (non-AP group); 1153 (24.6%) were ablation of left-sided accessory pathway, AP group; and 129 (2.8%) were ablation of ventricular tachycardia. Transseptal puncture was done under fluoroscopy, pressure monitoring, and commonly using contrast media injection. In 27 procedures, ICE or TEE was used to guide the TP. We found 34 tamponades (Tx) that required pericardial drainage of which 28 (0.59%) could possibly be TP related and six could not. The total complication rate for all Tx was 0.72%. A higher rate of tamponades was observed in the AF (non-AP) group than in the AP group (0.88 vs. 0.17%, P < 0.02). The highest rate of tamponades was registered during the operators 51-100 cases, 1.3%, and decreased to 0.4% in cases 101-200, P = 0.04. CONCLUSION: TP can safely be done under fluoroscopy and pressure monitoring without routine use of additional techniques. With experience, operators should be able to further decrease complication rate.

Women with PSVT are often misdiagnosed, referred later than men, and have more symptoms after ablation.

OBJECTIVES: Using a patient and gender perspective, this study evaluates the experiences and perspectives of referral for paroxysmal supraventricular tachycardia (PSVT), and symptoms, Health-Related Quality of Life (HRQOL) and functional impairment before and six months after ablation. DESIGN: This prospective study includes 214 (109 women) patients with PSVT who completed questionnaires before and after ablation addressing referral patterns, duration of arrhythmia, socioeconomic status, symptoms, HRQOL, and functional impairment. RESULT: Women had a longer history of symptomatic arrhythmia before ablation compared to men (16.2 ± 14.6 vs. 9.9 ± 13.1 years, p = .001). From the patient's perspective, physicians more often incorrectly interpreted women's symptoms as anxiety, stress, panic attacks, or depression compared to men, delaying referral for ablation. More women than men stated they were not taken seriously when consulting for their tachycardia symptoms (17% vs.7%, p = .03). At baseline, there were minor differences between the sexes in HRQOL and functional impairment, but women had a higher symptom score on Symptoms Checklist Frequency (19 vs. 14, p < .001) and Severity Scale (12 vs. 16, p = .001). At six months, women were more symptomatic and their HRQOL improved less than in men. Both sexes reported improvement in recreation and pastime (p = .001). CONCLUSION: Women with PSVT are referred for ablation later, and are more symptomatic before and after ablation than men. Symptoms due to PSVT are often incorrectly diagnosed as panic attacks, stress, anxiety, or depression, misdiagnoses that delay referral for ablation, especially for women.

Impact of cavotricuspid isthmus morphology in CRYO versus radiofrequency ablation of typical atrial flutter.

OBJECTIVES: Cryoablation (CRYO) is an alternative to radiofrequency (RF) for catheter ablation of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL). We aimed to study whether different CTI morphologies had different impacts on procedural success for CRYO and RF. DESIGN: This study randomized 153 patients with CTI-dependent AFL (median age 65 years; range 34-82) to RF or CRYO (78 CRYO; 75 RF). Biplane angiography (RAO 30° and LAO 60°) was done before the ablation procedure and isthmuses were classified as straight (n = 81), concave (n = 43) or pouch-like (n = 29). RF was performed with a 3.5-mm open-irrigated tip catheter and CRYO was performed with a 9 F, 8-mm tip catheter. The ablation endpoint was bidirectional block of CTI. RESULTS: Acute procedural success was achieved in 70/75 patients in the RF group and in 72/78 patients in the CRYO group. With regard to CRYO or RF, acute procedural success rates were similar between the three isthmus types: straight: CRYO (92%) and RF (96%); concave: CRYO (92%) and RF (94%); and pouch-like: CRYO (94%) and RF (85%). There were no significant differences regarding success rate between the different morphologies in the CRYO or the RF group. The CTI was longer in patients with acute failure compared to the patients with acute success (38 ± 7 mm versus 33 ± 6 mm, p = 0.045). CONCLUSION: The CTI morphology did not influence the acute success rate for either the CRYO or the RF ablation of CTI-dependent AFL. A longer CTI was associated with a lower success rate regardless of energy source.

Number of Beats in the Transition Zone With Fixed SA Interval during Right Ventricular Overdrive Pacing Determines Accessory Pathway Location in Orthodromic Reentrant Tachycardia.

BACKGROUND: Ventricular overdrive pacing (VOP) produces reset during the transition zone (TZ) of QRS fusion in orthodromic reentrant tachycardia (ORT) and after the TZ in atrioventricular nodal reentrant tachycardia (AVNRT), and this represents a simple diagnostic maneuver to differentiate the two tachycardia mechanisms. OBJECTIVE: The purpose of this study was to determine whether the number of beats with reset in the TZ predicts accessory pathway (AP) location in ORT. METHODS: We retrospectively reviewed 57 patients with ORT (21 left-sided AP, 20 septal AP, and 16 right-sided AP) and 20 patients with AVNRT (19 typical AVNRT and one atypical AVNRT) who underwent VOP from the right ventricular apex. We analyzed the number of beats with reset during or after the TZ, demonstrated by fixed ventricular stimulus-atrial (SA) interval during VOP. RESULTS: The overall mean tachycardia cycle length [CL] minus VOP CL was 22.6 ± 7.5 ms with no statistical difference between the groups (P = 0.480). The mean number of beats in the TZ with fixed SA interval was 2.5 ± 1.4 for the whole ORT group, 1.1 ± 0.4 for left-sided AP (range 1-2), 2.8  ±  0.9 for septal AP (range 1-5), and 4.0 ± 0.9 for right-sided AP (range 3-6) (P < 0.001). Using a cutoff >2 beats distinguished right- versus left-sided AP in all cases. CONCLUSION: Assessing the number of beats in the TZ with fixed SA interval during VOP helps to determine AP location in ORT and adds valuable information to an established simple diagnostic pacing maneuver, especially when a two-catheter simplified approach is employed.

Coffee consumption is not associated with increased risk of atrial fibrillation: results from two prospective cohorts and a meta-analysis.

BACKGROUND: Whether coffee consumption affects the risk of developing atrial fibrillation (AF) remains unclear. We sought to investigate the association between coffee consumption and incidence of AF in two prospective cohorts, and to summarize available evidence using a meta-analysis. METHODS: Our study population comprised 41,881 men in the Cohort of Swedish Men and 34,594 women in the Swedish Mammography Cohort who had provided information on coffee consumption in 1997 and were followed up for 12 years. Incident cases of AF were ascertained by linkage with the Swedish Hospital Discharge Register. For the meta-analysis, prospective studies were identified by searching PubMed and Embase through 22 July 2015, and by reviewing the reference lists of retrieved articles. Study-specific relative risks were combined using a random effects model. RESULTS: We ascertained 4,311 and 2,730 incident AF cases in men and women, respectively, in the two cohorts. Coffee consumption was not associated with AF incidence in these cohort studies. The lack of association was confirmed in a meta-analysis, including six cohort studies with a total of 10,406 cases of AF diagnosed among 248,910 individuals. The overall relative risk (95% confidence interval) of AF was 0.96 (0.84-1.08) for the highest versus lowest category of coffee consumption, and 0.99 (0.94-1.03) per 2 cups/day increment of coffee consumption. CONCLUSIONS: We found no evidence that coffee consumption is associated with increased risk of AF.

Comparison of regular atrial tachycardia incidence after circumferential radiofrequency versus cryoballoon pulmonary vein isolation in real-life practice.

BACKGROUND: Postablation atrial tachycardia (AT) is a significant complication following radiofrequency (RF) pulmonary vein isolation (PVI). Cryoballoon (CB) ablation is an alternative technique for PVI that appears to have a low incidence of AT. No direct comparison between AT risk in RF and CB ablation has been made. OBJECTIVE: To compare the incidence and characteristics of ATs after PVI with RF and with CB ablation in patients with paroxysmal atrial fibrillation (AF). METHODS: All patients who underwent their first PVI between January 2006 and September 2012 using either RF or CB ablation were included. When a repeat ablation procedure for AT was performed, the arrhythmia was classified as typical cavotricuspid isthmus (CTI) flutter or left atrial tachycardia (LA-AT) based on invasive mapping procedure findings and ECG P-wave morphology. RESULTS: The study population consisted of 415 and 215 consecutive patients in the RF and CB groups, respectively. After a mean follow-up of 38 ± 21 months, 52 (8.3%) patients presented ATs (9.4% and 6% in the RF and CB groups, respectively; P = 0.15). Of those, 26 (4.1%) were classified as LA-AT with 20 (4.8%) in the RF group and 6 (2.8%) in the CB group (P = 0.23). In patients without a history of typical CTI flutter or CTI line (n = 458), the incidence for this type of arrhythmia during follow-up was 3.5%. CONCLUSION: In patients with paroxysmal AF undergoing either RF or CB PVI as the sole ablation strategy, the incidence of postprocedural AT was low and there was no significant difference between the 2 techniques.