Prevalence and Associated Factors of Paroxysmal Atrial Fibrillation and Atrial Arrhythmias During Hospitalizations for Exacerbation of COPD.

Purpose: This study aimed to investigate the proportion and risk factors of paroxysmal atrial fibrillation (AF) and atrial arrhythmias (AA) in patients hospitalized for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in Vietnam. Patients and Methods: A prospective observational study was conducted at two major hospitals in Hanoi, Vietnam, from January 2022 to January 2023. A total of 197 AECOPD patients were recruited. ECG and 24-hour Holter ECG were used to diagnose paroxysmal AF and AA. Results: The prevalence of paroxysmal AF and AA were 15.2% and 72.6%, respectively. Factors associated with a higher likelihood of paroxysmal AF included aging 75 years old and above (aOR = 3.15; 95% CI: 1.28 to 8.48), Premature atrial complex (PAC) with 500 or more (aOR = 3.81; 95% CI: 1.48 to 10.97) and severity of COPD as group C and D (aOR = 3.41; 95% CI: 1.28 to 10.50). For AA, aging 75 years old and above (aOR = 2.25; 95% CI: 1.28 to 5.20), smoking (aOR = 2.10; 95% CI: 1.07 to 4.23) and P wave dispersion (PWD) with 40 milliseconds or more (aOR = 3.04; 95% CI: 1.54 to 6.19) were associated with a higher likelihood of AA. Conclusion: Overall, our findings highlight the associated factors with the paroxysmal AF and AA among AECOPD patients. This underscores the importance of a multifaceted approach to risk assessment and management in this vulnerable population, focusing not only on respiratory symptoms but also on comprehensive cardiovascular evaluation and intervention.

Determinants of supraventricular extra beats in elite athletes practicing different sporting disciplines.

BACKGROUND: Supraventricular extra beats (SVEB) are frequently observed in athletes but data on significance, prognostic role and correlation with cardiac remodeling are contrasting. It is uncertain whether SVEB may indicate the development of more complex arrhythmias and the need for closer monitoring is undetermined. The aim was to assess the prevalence and clinical significance of BESV in Olympic athletes of different sporting disciplines, evaluating potential correlations with cardiac remodeling and clinical features. METHODS: We enrolled athletes who participated at 2012-2022 Olympic Games, submitted to physical examination, blood tests, echocardiography and exercise tests, categorized into power, skills, endurance and mixed disciplines. RESULTS: We studied 1492 elite athletes: 56% male individuals, mean age 25.8 ±â€Š5.1 years; 29.5% practiced power, 12.3% skills, 21% endurance and 37.2% mixed disciplines. At exercise-stress tests, 6.2% had SVEB, mostly single beats. SVEB were not influenced by anthropometrics or blood test results. They were more common in male individuals (77.4 vs. 54.6%, P < 0.0001) and older athletes (27.1 ±â€Š5.7 vs. 25.7 ±â€Š5.1, P = 0.01). In male athletes with SVEB, higher left atrial volumes were observed (24.2 ±â€Š7.3 vs. 22.2 ±â€Š7.1 ml/m2, P = 0.03). No differences were found in terms of sporting discipline: despite larger left atrial dimensions in aerobic disciplines, SVEB rates were similar in different sporting disciplines (6.1% endurance, 6.3% mixed, 5.2% power and 8.7% skills; P = 0.435). CONCLUSION: SVEB were more common in older, male athletes and associated with higher left atrial volume (especially in male individuals) regardless of sport practiced. Athletes with greater left atrial volume and SVEB are supposed to have higher risk, in middle age, of developing more complex arrhythmias.

Atrial Imaging and Cardiac Rhythm in Cryptogenic Embolic Stroke: The ARIES Study.

BACKGROUND: Unknown cardioembolic sources are frequent causes of cryptogenic stroke. We analyzed the risk of atrial fibrillation (AF) or high burden of ectopic atrial activity (HBEA) in patients with cryptogenic stroke, assessing atrial function and 1-year outcomes. METHODS AND RESULTS: The ARIES (Atrial Imaging and Cardiac Rhythm in Cryptogenic Embolic Stroke) study is an observational study including patients with cryptogenic stroke. We analyzed the frequency of AF and HBEA (>3000 atrial ectopic beats/day or >2 bursts or atrial tachycardia between 3 beats and ≤30 seconds) in two 30-day Holter-ECGs, comparing advanced echocardiography signs of left atrial (LA) dysfunction according to rhythm: AF, HBEA, and normal sinus rhythm. We also evaluated 1-year stroke recurrence and mortality. The study included 109 patients; 35 (32.1%) patients had AF, 27 (24.8%) HBEA, and 47 (43.1%) normal sinus rhythm. Compared with those with normal sinus rhythm, patients with AF presented higher 2-dimensional and 3-dimensional LA indexed volumes (38.8±11.2 versus 27.3±11.8 mL/m2, and 50.6±17.2 versus 34.0±15.4 mL/m2, respectively, P<0.001), lower 3-dimensional LA ejection fraction (50±14.6 versus 62.7±11.8, P=0.001), LA reservoir strain (22.0±8.6 versus 30.4±10.5, P<0.001), and LA contraction strain (10.5±8.18 versus 17.1±7.5, P<0.001), remaining significant in multivariate analysis. Patients with HBEA showed higher LA indexed volumes and lower LA reservoir strain than patients with normal sinus rhythm only in univariate analysis. There were no differences in ischemic recurrence or mortality among the groups. CONCLUSIONS: Patients with cryptogenic stroke showed a high incidence of AF and HBEA. AF is strongly related to LA volume, LA function, and LA reservoir and contraction strain, whereas HBEA showed milder structural changes. Advanced LA echocardiography could help patient selection for long-term ECG monitoring in suspected cardiac sources.

Association between obstructive sleep apnea and arrhythmia and heart rate variability among hypertensive patients.

BACKGROUND: The relationship between obstructive sleep apnea (OSA) and the occurrence of arrhythmias and heart rate variability (HRV) in hypertensive patients is not elucidated. Our study investigates the association between OSA, arrhythmias, and HRV in hypertensive patients. METHODS: We conducted a cross-sectional analysis involving hypertensive patients divided based on their apnea-hypopnea index (AHI) into two groups: the AHI ≤ 15 and the AHI > 15. All participants underwent polysomnography (PSG), 24-hour dynamic electrocardiography (DCG), cardiac Doppler ultrasound, and other relevant evaluations. RESULTS: The AHI > 15 group showed a significantly higher prevalence of frequent atrial premature beats and atrial tachycardia (P = 0.030 and P = 0.035, respectively) than the AHI ≤ 15 group. Time-domain analysis indicated that the standard deviation of normal-to-normal R-R intervals (SDNN) and the standard deviation of every 5-minute normal-to-normal R-R intervals (SDANN) were significantly higher in the AHI > 15 group (P = 0.020 and P = 0.033, respectively). Frequency domain analysis revealed that the low-frequency (LF), high-frequency (HF) components, and the LF/HF ratio were also significantly elevated in the AHI > 15 group (P < 0.001, P = 0.031, and P = 0.028, respectively). Furthermore, left atrial diameter (LAD) was significantly larger in the AHI > 15 group (P < 0.001). Both univariate and multivariable linear regression analyses confirmed a significant association between PSG-derived independent variables and the dependent HRV parameters SDNN, LF, and LF/HF ratio (F = 8.929, P < 0.001; F = 14.832, P < 0.001; F = 5.917, P = 0.016, respectively). CONCLUSIONS: Hypertensive patients with AHI > 15 are at an increased risk for atrial arrhythmias and left atrial dilation, with HRV significantly correlating with OSA severity.

Diagnostic reliability of monitoring for premature atrial and ventricular complexes.

AIMS: Short-term ambulatory electrocardiogram (ECG) monitoring is often used to assess premature atrial complex (PAC) and premature ventricular complex (PVC) frequency, but the diagnostic reliability is unknown. The objective of this study was to study the day-to-day variability of PAC and PVC frequency. METHODS AND RESULTS: We used 14-day full-disclosure mobile cardiac telemetry recordings without atrial fibrillation in 8245 US patients aged 17-103 years to calculate the diagnostic reliability of shorter ambulatory ECG recordings compared with 14-day averages. Over 14 days, 1853 patients had ≥500 PACs/day, 410 patients had ≥5000 PACs/day, and 197 patients had ≥10 000 PACs/day; 1640 patients had ≥500 PVCs/day, 354 patients had ≥5000 PVCs/day, and 175 patients had ≥10 000 PVCs/day. After 3 days, the estimated daily PAC frequency differed by ≥50% from the 14-day mean in 25% of patients; for PVCs, the corresponding duration was 7 days. Ten days of monitoring were needed to estimate PAC and PVC frequency within ±20% of the overall 14-day frequency in 80% of patients. For daily PAC and PVC frequencies ≥10 000, single-day estimation had a specificity of 99.3% [95% confidence interval (CI) 99.1-99.5] at a sensitivity of 76.6 (95% CI 70.1-80.4%) for PACs and a 99.6% (95% CI 99.4-99.7%) specificity at 79.4 (95% CI 72.7-85.2) sensitivity for PVCs. After 7 days, the sensitivity increased to 88.8% (95% CI 83.6-92.9) for PACs and 86.9% (95% CI 80.9-91.5%) for PVCs. CONCLUSION: While there is substantial daily variability across most PAC and PVC levels, findings of ≥10 000 PACs or PVCs are highly specific and do not need to be confirmed with longer recordings.

Association between blood pressure levels and premature atrial contractions in patients with hypertension.

BACKGROUND: High blood pressure (BP) induces left atrial structural and functional remodeling that increases susceptibility to atrial arrhythmia. We hypothesized that lower systolic BP (SBP) levels are associated with a lower prevalence of premature atrial contractions (PACs) in patients with hypertension. METHODS: This analysis included 4,697 participants (mean age 62±13.1 years, 50% women, 25.6% blacks) with hypertension from the Third National Health and Nutrition Examination Survey who did not have a prior history of cardiovascular disease (CVD). Multivariable logistic regression was used to examine the cross-sectional association between SBP and prevalence of PACs ascertained from 12-lead resting electrocardiograms. Multivariable Cox proportional hazard analysis was used to examine the association between baseline PACs and CVD mortality. RESULTS: Approximately 1.6% (n=74) of participants had baseline PACs. Patients with SBP ≤140 mmHg had a lower prevalence of PACs than those with SBP ≥140 mmHg (1.1% vs. 1.9%, p-value=0.01). In a multivariable logistic regression model, each 10 mmHg decrease in SBP was associated with a 12% lower odds of PACs (OR (95%CI): 0.88 (0.77-0.99)). During 14 years of follow-up, 645 CVD deaths occurred. In a multivariable-adjusted Cox model, presence of PACs was associated with a 78% increased risk of CVD mortality (HR (95%CI): 1.78 (1.23-2.60)). CONCLUSIONS: In patients with hypertension, lower SBP levels are associated with a lower prevalence of PACs, and presence of PACs is associated with a higher risk of CVD mortality risk. These findings highlight the potential role of BP lowering in the management of cardiac arrhythmias.

Sympathetic toggled paroxysmal atrial fibrillation and recurrent premature atrial contractions in ambulatory patients.

BACKGROUND: Autonomic nerve activity is important in the mechanisms of paroxysmal atrial fibrillation (PAF). OBJECTIVE: The purpose of this study was to test the hypothesis that a single burst of skin sympathetic nerve activity (SKNA) can toggle on and off PAF or premature atrial contraction (PAC) clusters. METHODS: Simultaneous recording of SKNA and electrocardiogram (neuECG) recording was performed over 7 days in patients with PAF. RESULTS: In study 1, 8 patients (7 men and 1 woman; age 62 ± 8 years) had 124 episodes of PAF. An SKNA burst toggled both on and off PAF in 8 episodes (6.5%) (type 1), toggled on but not off in 12 episodes (9.7%) (type 2), and toggled on a PAC cluster followed by PAF in 4 episodes (3.2%) (type 3). The duration of these PAF episodes was <10 minutes. The remaining 100 episodes (80.6%) were associated with active SKNA bursts throughout PAF (type 4) and lasted longer than type 1 (P = .0185) and type 2 (P = .0027) PAF. There were 47 PAC clusters. Among them, 24 (51.1%) were toggled on and off, and 23 (48.9%) were toggled on but not off by an SKNA burst. In study 2, 17 patients (9 men and 8 women; age 58 ± 12 years) had <10 minutes of PAF (4, 8, 0, and 31 of types 1, 2, 3, and 4, respectively). There were significant circadian variations of all types of PAF. CONCLUSION: A single SKNA burst can toggle short-duration PAF and PAC cluster episodes on and off. The absence of continued SKNA after the onset might have affected the maintenance of these arrhythmias.

Upper common pathway analysis using late atrial premature depolarization in atrioventricular nodal reentry tachycardia.

BACKGROUND: Anatomic and electrophysiologic findings suggest that the actual circuit of atrioventricular nodal reentrant tachycardia (AVNRT) involves the perinodal atrium. However, occasional instances in which the atrium is dissociated from the AVNRT have led to the concept of an upper common pathway (UCP). OBJECTIVE: We aimed to assess the prevalence of UCP in AVNRT using a late atrial premature depolarization (LAPD) maneuver. METHODS: Patients who were diagnosed with typical AVNRT by electrophysiologic studies were enrolled. For evaluation of the presence of UCP, an LAPD was given at the coronary sinus ostium (osCS) during AVNRT, and then pacing was repeated incrementally every 10 ms. Electrograms in the earliest retrograde atrial activation site (ERAS) near the proximal His were mapped and recorded during the pacing. Results were interpreted as follows: absence of UCP-an LAPD from the osCS can reset the tachycardia without depolarizing the ERAS; presence of UCP-an LAPD from the osCS can depolarize the ERAS without resetting the tachycardia; and indeterminate-an LAPD from the osCS either resets the ERAS and tachycardia simultaneously or does not reset both. RESULTS: The LAPD maneuver was performed in 126 patients with AVNRT. It demonstrated an absence of UCP in 121 (96.0%) patients and the presence of UCP in 3 (2.4%) patients; the result was indeterminate in 2 (1.6%) patients. CONCLUSION: The LAPD maneuver revealed that the presence of UCP is indicated in only rare cases of AVNRT. In most AVNRT cases, the atrium is involved in the reentry circuit.

Premature atrial contractions with multiple patterns of aberrant conduction followed by torsade de pointes in a patient with polymyalgia rheumatica: A case report.

RATIONALE: Recent studies have shown that QT interval prolongation is associated with disease severity and predicts mortality in systemic inflammatory diseases, particularly rheumatoid arthritis. Systemic pro-inflammatory cytokines released from synovial tissues in rheumatoid arthritis, such as interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α, could have direct effects on cardiac electrophysiology, particularly changes in the expression and function of potassium and calcium channels, resulting in QT interval prolongation on surface electrocardiogram (ECG) and an increased predisposition to develop lethal ventricular arrhythmias. However, reports on torsade de pointes (TdP) due to acquired long QT syndrome in patients with polymyalgia rheumatica (PMR) are limited. PATIENT CONCERNS: An 85-year-old Japanese woman with active PMR developed first syncope. DIAGNOSIS: Frequent premature atrial contractions (PACs) with multiple patterns of aberrant conduction, QT interval prolongation, and morphological T-U wave variability followed by TdP were documented. PACs were the first beat of TdP. INTERVENTIONS: Amiodarone, together with magnesium and potassium, was intravenously administered. However, TdP resulted in a ventricular arrhythmic storm, for which sedation with mechanical ventilatory support, temporary overdrive cardiac pacing, and intravenous landiolol administration in addition to multiple direct current shocks were effective. OUTCOMES: Approximately 2 years later, the patient was treated with amiodarone, propranolol, and prednisolone. She did not undergo implantable cardioverter-defibrillator implantation and was quite well, with no recurrence of ventricular tachyarrhythmia. LESSONS: IL-6 hyperproduction in inflamed tissues has been widely confirmed in PMR. Frequent PACs with various patterns of aberrant conduction, QT interval prolongation, and morphological T-U wave variability followed by TdP, for which IL-6-mediated enhancement of L-type Ca2+ current and inhibition of the rapid component of the delayed rectifier K+ current are the most likely mechanisms, were documented in an elderly Japanese woman with PMR. ECG may be recorded once in patients with active PMR even when these patients do not complain of palpitation or syncope. If QT interval prolongation or arrhythmia, including even PACs, is observed, follow-up ECG may be warranted, particularly for patients with some risk factors for QT prolongation that could lead to TdP, such as advanced age, female sex, hypopotassemia, and polypharmacy.

Prognostic Implications of Supraventricular Arrhythmias.

The aim of this study was to establish the prevalence and prognostic implication of progressive supraventricular arrhythmias from frequent supraventricular ectopic complexes, isolated, in bi- or trigeminy, to supraventricular tachycardias with different characteristics. In the STROKESTOP I mass-screening study for atrial fibrillation (AF) in 75- and 76-year olds in Sweden, participants registered 30-second intermittent ECG twice daily for two weeks. The ECG-recordings from STROKESTOP I were re-evaluated using an automated algorithm to detect individuals with frequent supraventricular ectopic complexes or runs. Detected episodes were manually re-examined to confirm the findings. The primary endpoint was AF as ascertained from the national Swedish Patient register. Exploratory secondary endpoints were stroke and death. Median follow-up was 4.2 (interquartile range [IQR] 3.8-4.4) years. Of the examined 6,100 participants, 85% were free of significant supraventricular arrhythmia. In the 894 participants that had arrhythmia, frequent supraventricular ectopic complexes were the most common arrhythmia, n = 709 (11.6%) and irregular supraventricular tachycardias were more common than regular. Individuals with the most AF similar supraventricular tachycardias, irregular and lacking p-waves (termed micro-AF), n = 97 (1.6%) had the highest risk of developing AF (hazard ratio 4.3; 95% confidence interval [CI] 2.7-6.8). They also had increased risk of death (hazard ratio 2.0; CI 1.1-3.8). In conclusion, progression of atrial arrhythmias from supraventricular ectopic complexes to more AF-like episodes is associated with development of AF. Extended screening for AF should be considered in individuals with frequent supraventricular activity, especially in those with supraventricular tachycardias with AF characteristics.

Frequent Premature Atrial Contractions Are Associated With Poorer Cognitive Function in the Atherosclerosis Risk in Communities (ARIC) Study.

OBJECTIVE: To evaluate the association of premature atrial contraction (PAC) frequency with cognitive test scores and prevalence of dementia or mild cognitive impairment (MCI). MATERIALS AND METHODS: We conducted a cross-sectional analysis using Atherosclerosis Risk in Communities study visit 6 (January 1, 2016, through December 31, 2017) data. We included 2163 participants without atrial fibrillation (AF) (age mean ± SD, 79±4 years; 1273 (58.9%) female; and 604 (27.97.0% Black) who underwent cognitive testing and wore a leadless, ambulatory electrocardiogram monitor for 14 days. We categorized PAC frequency based on the percent of beats: less than 1%, minimal; 1% to <5%, occasional; greater than or equal to 5%, frequent. We derived cognitive domain-specific factor scores (memory, executive function, language, and global z-score). Dementia and MCI were adjudicated. RESULTS: During a mean analyzable time of 12.6±2.6 days, 339 (15.7%) had occasional PACs and 107 (4.9%) had frequent PACs. Individuals with frequent PACs (vs minimal) had lower executive function factor scores by 0.30 (95% CI, -0.46 to -0.14) and lower global factor scores by 0.20 (95% CI, -0.33 to -0.07) after multivariable adjustment. Individuals with frequent PACs (vs minimal) had higher odds of prevalent dementia or MCI after multivariable adjustment (odds ratio, 1.74; 95% CI, 1.09 to 2.79). These associations were unchanged with additional adjustment for stroke. CONCLUSION: In community-dwelling older adults without AF, frequent PACs were cross-sectionally associated with lower executive and global cognitive function and greater prevalence of dementia or MCI, independently of stroke. Our findings lend support to the notion that atrial cardiomyopathy may be a driver of AF-related outcomes. Further research to confirm these associations prospectively and to elucidate underlying mechanisms is warranted.

Cardiotoxic Effects of Micrurus surinamensis (Cuvier, 1817) Snake Venom.

Micrurus surinamensis is a coral snake from the Elapidae family of wide distribution in Amazonia Forest. Its venom contains neurotoxins that induce muscular and respiratory paralysis; however, its cardiovascular action is not yet characterized. The aim of this study was to investigate the cardiotoxic effects caused by M. surinamensis poisoning in rodents. Twelve guinea pigs (Cavia porcellus) were distributed in two groups (n = 6) named as control and envenomed. The control group received 0.2 ml of PBS/BSA via intramuscular injection (IM), while envenomed animals received 0.75 µg of venom per g of body weight, also via IM. Electrocardiographic examination (ECG) and biochemical serum tests were conducted before and 2 h after inoculation. ECG of the envenomed animals revealed severe progressive arrhythmias including atrioventricular block, supraventricular, and ventricular extrasystoles. Serum biochemistry showed significant increase in CK, CK-MB, and LDH enzymes corroborating the skeletal and cardiac muscle damage. Myonecrosis and degeneration were observed in both skeletal and heart muscle; nevertheless, transmission electron microscopy revealed cardiac muscle fibers fragmentation. In conclusion, M. surinamensis venom has a potent cardiotoxic activity eliciting arrhythmogenic effects and heart damage after only 2 h of envenomation.

Autonomic regulation of the heart and arrhythmogenesis in trained breath-hold divers.

AbstractBreath-hold divers are known to develop cardiac autonomic changes and brady-arrthymias during prolonged breath-holding (BH). The effects of BH-induced hypoxemia were investigated upon both cardiac autonomic status and arrhythmogenesis by comparing breath-hold divers (BHDs) to non-divers (NDs). Eighteen participants (9 BHDs, 9 NDs) performed a maximal voluntary BH with face immersion. BHDs were asked to perform an additional BH at water surface to increase the degree of hypoxemia. Beat-to-beat changes in heart rate (HR), short-term fractal scaling exponent (DFAα1), the number of arrhythmic events [premature ventricular contractions (PVCs), premature atrial contractions (PACs)] and peripheral oxygen saturation (SpO2) were recorded during and immediately following BH. The corrected QT-intervals (QTc) were analyzed pre- and post-acute BH. A regression-based model was used to split BH into a normoxic (NX) and a hypoxemic phase (HX). During the HX phase of BH, BHDs showed a progressive decrease in DFAα1 during BH with face immersion (p < 0.01) and BH with whole-body immersion (p < 0.01) whereas NDs did not (p > 0.05). In addition, BHDs had more arrhythmic events during the HX of BH with whole-body immersion when compared to the corresponding NX phase (5.9 ± 6.7 vs 0.4 ± 1.3; p < 0.05; respectively). The number of PVCs was negatively correlated with SpO2 during BH with whole-body immersion (r = -0.72; p < 0.05). The hypoxemic stage of voluntary BH is concomitant with significant cardiac autonomic changes toward a synergistic sympathetic and parasympathetic stimulation. Co-activation led ultimately to increased bradycardic response and cardiac electrophysiological disturbances.

Atrial fibrillation is a marker of increased mortality risk in nonischemic heart failure-Results from the DANISH trial.

BACKGROUND: Atrial fibrillation (AF) in heart failure (HF) patients has been associated with a worse outcome. Similarly, excessive supraventricular ectopic activity (ESVEA) has been linked to development of AF, stroke, and death. This study aimed to investigate AF and ESVEA's association with outcomes and effect of prophylactic implantable cardioverter defibrillator (ICD) implantation in nonischemic HF patients. METHODS: A total of 850 patients with nonischemic HF, left ventricle ejection fraction ≤35%, and elevated N-terminal pro-brain natriuretic peptides underwent 24 hours Holter recording. The presence of AF (≥30 seconds) and ESVEA (≥30 supraventricular ectopic complexes (SVEC) per hour or run of SVEC ≥20 beats) were registered. Outcomes were all-cause mortality, cardiovascular death (CVD), and sudden cardiac death (SCD). RESULTS: AF was identified in 188 patients (22%) and ESVEA in 84 patients (10%). After 4 years and 11 months of follow-up, a total of 193 patients (23%) had died. AF was associated with all-cause mortality (hazard ratio [HR] 1.44; confidence interval [CI] 1.04-1.99; P = .03) and CVD (HR 1.59; CI 1.07-2.36; P = .02). ESVEA was associated with all-cause mortality (HR 1.73; CI 1.16-2.57; P = .0073) and CVD (HR 1.76; CI 1.06-2.92; P = .03). Neither AF nor ESVEA was associated with SCD. ICD implantation was not associated with an improved prognosis for neither AF (P value for interaction = .17), nor ESVEA (P value for interaction = .68). CONCLUSIONS: Both AF and ESVEA were associated with worsened prognosis in nonischemic HF. However, ICD implantation was not associated with an improved prognosis for either group.

Novel Score to Predict Very Late Recurrences After Catheter Ablation of Atrial Fibrillation.

Various predictors of atrial fibrillation (AF) recurrence have been shown based on the baseline characteristics before catheter ablation (CA). This study aimed to develop a novel scoring system for predicting very late recurrences of AF (VLRAFs) after an initial CA, taking the postprocedural clinical data into account and reassessing VLRAFs in 12-month patients' condition using previously known preprocedural predictors of AF recurrences. We retrospectively studied 327 patients who underwent an initial CA with freedom from AF for over 12 months. We elucidated the predictors of VLRAFs and created a new score to predict VLRAFs in the discovery AF cohort (n = 181). Thereafter, we investigated whether the new scoring system could accurately predict VLRAFs in the validation AF cohort (n = 146). In the discovery AF cohort, VLRAFs were observed in 53 patients (29%) during the follow-up period (mean follow-up duration: 55 months). The univariate and multivariate Cox proportional-hazards model demonstrated that non-pulmonary vein foci, early recurrences of AF (ERAFs), atrial premature contraction (APC) burden ≥ 142/24 hours, and minimum prematurity index of the APCs ≤ 48% were associated with VLRAFs after CA. We created a new scoring system to predict VLRAFs, the n-PReDCt score (non-pulmonary vein: 1 point, early recurrences of AFs (Recurrences of AF in early phase after CA): 1 point, APC burden ≥ 142/24 hours: 1 point, and minimum prematurity index (= Coupling interval) of the APCs of ≤ 48%: 1 point). The n-PReDCt score was significantly associated with VLRAFs by a Kaplan-Meier analysis in the discovery AF and validation AF cohorts (p < 0.0001 and p < 0.0001, respectively).

Predictive value of premature atrial complex characteristics in pulmonary vein isolation for patients with paroxysmal atrial fibrillation.

BACKGROUND: Premature atrial complexes from pulmonary veins are the main triggers for atrial fibrillation in the early stages. Thus, pulmonary vein isolation is the cornerstone of catheter ablation for paroxysmal atrial fibrillation. However, the success rate remains perfectible. AIM: To assess whether premature atrial complex characteristics before catheter ablation can predict pulmonary vein isolation success in paroxysmal atrial fibrillation. METHODS: We investigated consecutive patients who underwent catheter ablation for paroxysmal atrial fibrillation from January 2013 to April 2017 in two French centres. Patients were included if they were treated with pulmonary vein isolation alone, and had 24-hour Holter electrocardiogram data before catheter ablation available and a follow-up of≥6 months. Catheter ablation success was defined as freedom from any sustained atrial arrhythmia recurrence after a 3-month blanking period following catheter ablation. RESULTS: One hundred and three patients were included; all had an acute successful pulmonary vein isolation procedure, and 34 (33%) had atrial arrhythmia recurrences during a mean follow-up of 30±15 months (group 1). Patients in group 1 presented a longer history of atrial fibrillation (71.9±65.8 vs. 42.9±48.4 months; P=0.008) compared with those who were "free from arrhythmia" (group 2). Importantly, the daily number of premature atrial complexes before catheter ablation was significantly lower in group 1 (498±1413 vs. 1493±3366 in group 2; P=0.028). A daily premature atrial complex cut-off number of<670 predicted recurrences after pulmonary vein isolation (41.1% vs. 13.3%; sensitivity 88.2%; specificity 37.7%; area under the curve 0.635; P=0.017), and was the only independent predictive criterion in the multivariable analysis (4-fold increased risk). CONCLUSION: Preprocedural premature atrial complex analysis on 24-hour Holter electrocardiogram in paroxysmal atrial fibrillation may improve patient selection for pulmonary vein isolation.

Premature Atrial Contractions and Their Association with Stroke Features and Outcome.

BACKGROUND: Frequent premature atrial contractions (PACs) are associated with atrial fibrillation, stroke, and mortality. However, the cut-off value for PAC counts that could identify patients with different stroke features is unclear, and the association of PACs to outcome is not determined. METHODS: The study retrospectively included patients with acute ischemic stroke who had underwent both a 24 h Holter recording and a brain MRI in Taipei Veterans General Hospital from January 2015 to May 2016. Patients were categorized into four groups according to their PAC frequencies on 24 h Holter recording. We compared the clinical severity, neuroimage features, stroke subtypes, and functional outcome among the four groups of patients. RESULTS: Among the 278 patients, the lower, middle, and upper quartiles of the PAC counts were 23, 74, and 459.5, respectively. In contrast to the 1st quartile of patients, the 3rd (PAC 75-459/24 h) and the 4th (PAC ≥460/24 h) quartiles of patients had higher NIH Stroke Scale (NIHSS) at admission (p = 0.014 and p = 0.002, respectively). The frequencies of cryptogenic stroke were not different among the 4 quartiles of the patients, but cryptogenic stroke patients with ≥ 75PACs/24hours had higher stroke severity compared to those with PACs < 75counts/24 h (NIHSS 9.1 vs. 5.2, p = 0.043). There was an increased trend in infarcts of multiple vascular territories and in mortality at 1 year among the four groups of patients with increased PAC frequency (p = 0.045 and p = 0.002, respectively). The 4th PAC quartile was associated with poor functional outcome (modified Rankin Scale ≥ 4) at 3 months in univariate analysis (OR: 5.66, CI: 2.69-11.91, p < 0.001), but was not an independent predictor after controlling for initial stroke severity. CONCLUSIONS: PACs ≥ 75 counts/24 h was associated with higher clinical severity in patients with acute ischemic stroke.

The ectopy-triggering ganglionated plexuses in atrial fibrillation.

BACKGROUND: Epicardial ganglionated plexuses (GP) have an important role in the pathogenesis of atrial fibrillation (AF). The relationship between anatomical, histological and functional effects of GP is not well known. We previously described atrioventricular (AV) dissociating GP (AVD-GP) locations. In this study, we hypothesised that ectopy triggering GP (ET-GP) are upstream triggers of atrial ectopy/AF and have different anatomical distribution to AVD-GP. OBJECTIVES: We mapped and characterised ET-GP to understand their neural mechanism in AF and anatomical distribution in the left atrium (LA). METHODS: 26 patients with paroxysmal AF were recruited. All were paced in the LA with an ablation catheter. High frequency stimulation (HFS) was synchronised to each paced stimulus for delivery within the local atrial refractory period. HFS responses were tagged onto CARTO™ 3D LA geometry. All geometries were transformed onto one reference LA shell. A probability distribution atlas of ET-GP was created. This identified high/low ET-GP probability regions. RESULTS: 2302 sites were tested with HFS, identifying 579 (25%) ET-GP. 464 ET-GP were characterised, where 74 (16%) triggered ≥30s AF/AT. Median 97 (IQR 55) sites were tested, identifying 19 (20%) ET-GP per patient. >30% of ET-GP were in the roof, mid-anterior wall, around all PV ostia except in the right inferior PV (RIPV) in the posterior wall. CONCLUSION: ET-GP can be identified by endocardial stimulation and their anatomical distribution, in contrast to AVD-GP, would be more likely to be affected by wide antral circumferential ablation. This may contribute to AF ablation outcomes.