Paroxysmal Supraventricular Tachycardia in Wolff-Parkinson-White Syndrome in a Newborn-Case Report and Mini-Review.

Wolff-Parkinson-White (WPW) syndrome is a rare abnormal condition frequently associated with paroxysmal supraventricular tachycardia (PSVT) and is described as an arrhythmia under the form of increased heartbeat. Currently, there are various possible treatments going from medicines such as adenosine and beta-blockers to cardioversion. The unknown causes of this condition together with the different responses to treatment in each patient make it difficult to establish the best therapeutic approach. In this context, in the current paper, we were interested in reporting the therapeutic options and their efficiency in the case of associated heart or inflammatory conditions in a 13-day-old patient.

Atrial fibrillation decision support tool: Population perspective.

BACKGROUND: Appropriate thromboprophylaxis for patients with atrial fibrillation or atrial flutter (AF) remains a national challenge. The recent availability of direct oral anticoagulants (DOACs) with comparable efficacy and improved safety compared with warfarin alters the balance between risk factors for stroke and benefit of anticoagulation. Our objective was to examine the impact of DOACs as an alternative to warfarin on the net benefit of oral anticoagulant therapy (OAT) in a real-world population of AF patients. METHODS: This is a retrospective cohort study of patients with paroxysmal or persistent nonvalvular AF. We updated an Atrial Fibrillation Decision Support Tool (AFDST) to include DOACs as treatment options. The tool generates patient-specific recommendations based upon individual patient risk factor profiles for stroke and major bleeding using quality-adjusted life-years (QALYs) calculated for each treatment strategy by a decision analytic model. The setting included inpatient and ambulatory sites in an academic health center in the midwestern United States. The study involved 5,121 adults with nonvalvular AF seen for any ambulatory visit or inpatient hospitalization over the 1-year period (January through December 2016). Outcome measure was net clinical benefit in QALYs. RESULTS: When DOACs are a therapeutic option, the AFDST recommends OAT for 4,134 (81%) patients and no antithrombotic therapy or aspirin for 489 (9%). A strong recommendation for OAT could not be made in 498 (10%) patients. When warfarin is the only option, OAT is recommended for 3,228 (63%) patients and no antithrombotic therapy or aspirin for 973 (19%). A strong recommendation for OAT could not be made in 920 (18%) patients. In total, 1,508 QALYs could be gained if treatment were changed to that recommended by the AFDST. CONCLUSIONS: Availability of DOACs increases the proportion of patients for whom oral anticoagulation therapy is recommended in a real-world cohort of AF patients and increased projected QALYs by more than 1,500 when all patients are receiving thromboprophylaxis as recommended by the AFDST compared with current treatment.

One symptom, two arrhythmias: the rare and the even rarer.

BACKGROUND: Wolff-Parkinson-White (WPW) syndrome and idiopathic left ventricular tachycardia (ILVT) are rare and up to now the coexistence of both entities has rarely been reported. In patients with ventricular preexcitation the underlying mechanism of paroxysmal tachycardia most likely is atrioventricular reentrant tachycardia (AVRT). However, without ECG documentation of the tachycardia diagnosis of the underlying mechanism cannot be made due to similar clinical presentation of AVRT and ILVT. CASE PRESENTATION: We report a case of a two-staged occurrence of two rare arrhythmias in a young adult, who was admitted to our hospital twice within 6 months because of paroxysmal tachycardia. WPW syndrome and ILVT as underlying arrhythmias have been diagnosed and were ablated successfully. CONCLUSIONS: This case highlights the diagnostic defiance of rare tachycardia entities and the paramount importance of ECG documentation and analysis of all available tachycardia ECGs.

High molecular weight fibroblast growth factor-2 as a promising prognostic biomarker to predict the occurrence of heart failure in atrial fibrillation patients.

Heart failure (HF) has a significant effect on the prognosis of the patients with atrial fibrillation (AF), and also it is an important risk factor for overall mortality. High molecular weight fibroblast growth factor-2 (Hi-FGF-2) is emerging as a prognostic marker with HF and AF. The aim of this study was to prove that Hi-FGF-2 would predict occurrence of HF in the patients with AF. Subjects diagnosed with paroxysmal AF (Group paAF), persistent AF (Group peAF) and sinus rhythm (Group SR) were enrolled in the study. Serum Hi-FGF-2 concentration was measured by ELISA at baseline. Multivariable logistic models and receiver operating characteristic (ROC) curve analysis were established to predict the prognosis of AF subjects. 260 patients were enrolled in the study: 104 (40.0%) admitted for sinus rhythm (Group SR) and 156 (60.0%) with AF (Group paAF and Group peAF). The Hi-FGF-2 levels were much lower in the Group SR (58.2 ± 27.1 ng/L) than in the Group AF. Furthermore, the Group peAF (84.3 ± 34.1 ng/L) had higher Hi-FGF-2 levels than the Group paAF (72.9 ± 35.8 ng/L). Serum Hi-FGF-2 levels were classified into trisection in the multivariable logistic model (T1 < 57.3 ng/L, 57.3 < T2 < 86.5 ng/L, and T3 > 86.5 ng/L). Hi-FGF-2 showed good predictive ability for new-onset HF in the patients with AF. The occurrence of HF was associated significantly with increased tertile of serum Hi-FGF-2 levels (T2: OR 5.922, 95% CI 1.109-31.626, P = 0.037 and T3: OR 8.262, 95% CI 1.735-39.343, P = 0.008). ROC curve analysis showed that the area under curves for Hi-FGF-2 were 0.720 (P < 0.0001). Hi-FGF-2 has a significant meaning in AF subjects. Further to this, higher circulating Hi-FGF-2 was highly related to persistent AF, and Hi-FGF-2 may be an independent risk factor of occurrence HF in AF subjects.

Paradoxical Embolism in a Girl with Atrial Septal Defect After Paroxysmal Supraventricular Tachycardia Ablation.

Paradoxical embolism is a kind of important pathogenesis of cardiocerebrovascular diseases. In our case, radiofrequency current catheter ablation was accomplished successfully in a 15-year-old girl who had been experiencing supraventricular tachycardia for 6 months. She presented with abrupt onset of left hemiplegia and loss of consciousness on the first postoperative day. An urgent cerebral computed tomography showed a hyperdense right middle cerebral artery. Transthoracic echocardiogram examination revealed an atrial septal defect (ASD), with the diameter measuring 39 mm. The case highly suggests that the issue of ASD should be resolved by either closed or prompt anticoagulant therapy, especially for patients who are planned to receive catheter manipulation.

[Regulatory adaptive status in determining the effectiveness of bisoprololum and sotalolum in patients with hypertensive disease and paroxysmal supraventricular tachycardia].

AIM: To determine efficacy of bisoprolol and sotalol treatments in patients with paroxysmal supraventricular tachycardia (SVT) and essential hypertension (EH) considering effects of these treatments on the regulatory adaptive status (RAS). MATERIALS AND METHODS: The study included 49 patients with paroxysmal SVT associated with stage II-III EH randomized to two groups of either bisoprolol (6.9±2.2 mg/day, n=25) or sotalol (162.5±46.2 mg/day, n=24) treatment. Lisinopril (14.5±3.9 and 14.3±4.7 mg/day) and, if indicated, atorvastatin (15.4±3.8 mg/day, n=9 and 16.0±4.8 mg/day, n=10), and acetylsalicylic acid (91.5±14.7 mg/day, n=12 and 94.1±16.5 mg/day, n=14) were administered as a part of combination therapy. Quantitative evaluation of RAS (cardiorespiratory synchronism test), EchoCG, triplex scanning of brachiocephalic arteries, treadmill test, 6-min walk test, 24-h BP and ECG monitoring, and subjective assessment of the quality of life were performed at baseline and after 6 months of therapy. RESULTS: Both regimens of the combination drug therapy comparably improved the structural and functional status of the heart, increased exercise tolerance, effectively suppressed SVT paroxysms, and improved the quality of life. In this process, sotalol reduced RAS to a lesser extent that bisoprolol. CONCLUSION: In patients with paroxysmal SVT associated with stage II-III EH, the sotalol treatment as a part of the combination therapy may be preferable due to fewer adverse effects on RAS compared to bisoprolol.

Electrocardiographic and Echocardiographic predictors of paroxysmal atrial fibrillation detected after ischemic stroke.

BACKGROUND: Detection of atrial fibrillation after ischemic stroke is challenging due to its paroxysmal nature. We aimed to assess predictors of paroxysmal atrial fibrillation using non-invasive surface ECG and transthoracic echocardiography to select candidates for atrial fibrillation screening. METHODS: Ischemic stroke patients without documented atrial fibrillation (n = 110, 67 ± 10 years, 40 female) and a control group of age- and gender-matched patients with history of paroxysmal atrial fibrillation prior to stroke (n = 55, 67 ± 10 years, 19 female) comprised the study sample. Using non-invasive ECG monitoring for three weeks, short episodes of paroxysmal atrial fibrillation were detected in 24 of 110 patients (22 %). The standard 12-lead ECG with sinus rhythm at stroke onset was digitally processed and analyzed. Transthoracic echocardiography data were reviewed for these patients. RESULTS: Atrial fibrillation history was independently associated with P terminal force in lead V 1 > 40 mm*ms (OR 4.04 95 % CI 1.34-12.14, p = 0.013) and left atrial volume index (OR 1.08 95 % CI 1.03-1.13, p = 0.002; for LAVI > 40 mL/m2 OR 6.40 95 % CL 1.47-27.91, p = 0.013). Among patients without atrial fibrillation history, no ECG characteristics were predictive of atrial fibrillation detected after stroke. Left atrial volume index remained an independent predictor of atrial fibrillation detected after stroke (OR 1.09 95 % CI 1.02-1.16, p = 0.017). A cutoff of <40 mL/m2 had an 84 % negative predictive value for ruling out atrial fibrillation on ambulatory monitoring with a sensitivity of 50 % and a specificity of 86 %. CONCLUSION: In a post hoc analysis, left atrial dilatation assessed by left atrial volume index independently predicted atrial fibrillation after stroke in patients without prior atrial fibrillation history, while the other clinical or ECG markers were not predictive of atrial fibrillation detected early after ischemic stroke. TRIAL REGISTRATION: This study is a post hoc analysis from the prospective case-control study registered in December 2011, ClinicalTrials.gov ID: NCT01325545 .

Paroxysmal supraventricular tachycardia in pregnant women and birth outcomes of their children: a population-based study.

The aim of the study was to estimate the possible association of pregnant women with paroxysmal supraventricular tachycardia (PSVT) with the possible risk for adverse birth outcomes, particularly different congenital abnormalities (CAs) in their children. Prospectively and medically recorded PSVT was evaluated in 103 pregnant women who later had offspring with CA (case group) and 149 pregnant women who later delivered newborn infants without CA (control group) and matched to cases in the population-based data set of the Hungarian Case-Control Surveillance System of Congenital Abnormalities, 1980-1996. Of 252 pregnant women with PSVT, 115 (45.6%) had the onset of this condition before the study pregnancy, that is, their PSVT was a chronic condition, while the rest (N = 137) of PSVT was considered as new onset in the study pregnancy. The comparison of occurrence of PSVT in pregnant women who had offspring with different CA groups and in control mothers showed a higher risk for cardiovascular CAs (adjusted OR with 95% CI: 2.1, 1.1-3.8) explained mainly by secundum atrial septal defect. This association was confirmed in pregnant women with PSVT in the second and/or third gestational month, that is, critical period of cardiovascular CAs. In conclusion PSVT in pregnant women associates with a higher risk of secundum atrial septal defect in their children.

[Anterior Mediastinal Bronchogenic Cyst Associated with paroxysmal supraventricular tachycardia ; Report of a Case].

We experienced a rare case of anterior mediastinal bronchogenic cyst. A 55-year-old female was admitted to our hospital because of paroxysmal supraventricular tachycardia (PSVT) and an abnormal shadow on the chest computed tomography. She had a 5.5 cm tumor at anterior mediastinum. The tumor was surgically removed completely by video assisted thoracoscopic surgery, and the diagnosis of bronchogenic cyst was established pathologically. After surgery, PSVT has disappeared.

[Predictors of Efficacy of Radiofrequency Ablation of Pulmonary Veins Performed During Coronary Bypass Surgery in Patients With Ischemic Heart Disease and Paroxysmal Atrial Fibrillation].

We performed simultaneous coronary artery bypass grafting (CABG) and radiofrequency ablation (RFA) ostia of pulmonary veins in 254 patients (147 men and 107 women) with ischemic heart disease and paroxysmal atrial fibrillation (AF). In-hospital mortality in patients with early recurrence of AF was 8.4%, in patients without recurrence of AF 1.9% (χ2 = 4.65; p = 0.03). The patients were followed-up during 12 months after operation. During follow-up 166 patients (69.5%) had no recurrence of AF without receiving antiarrhythmic drugs (AAP), 33 patients (13.8%) had recurrences of AF, and 40 patients (16.7%) receiving AAD had repeated rare paroxysms of AF. Main predictors of late AF recurrence were age > 65 years, AF duration > 5 years, preoperative atrial effective refractory period < 240 ms, frequency threshold of AF induction < 400 counts/min, anteroposterior left atrial size > 50 mm, glomerular filtration rate < 60 ml/min/1.73 m2. Reverse dynamics of structural, functional and electrophysiological parameters of the heart due to CABG and RFA, use of ß-blockers, angiotensin converting enzyme inhibitors and aldosterone antagonists were associated with the preservation of a stable sinus rhythm. The cardiovascular mortality during 12 months follow-up accounted for 2.1% and 1.2% in groups of patients with and without late recurrences of AF respectively (p > 0.05) to coronary artery bypass grafting surgery and RFA, taking drugs--ß-blockers, angiotensin converting enzyme inhibitors and aldosterone antagonists--were associated with the preservation of a stable sinus rhythm.

Comparison between CHADS2 and CHA2DS2-VASc score for risk stratification of ischemic stroke in Japanese patients with non-valvular paroxysmal atrial fibrillation not receiving anticoagulant therapy.

It remains unclear if the CHADS2 score or CHA2DS2-VASc score is more useful for the risk stratification of ischemic stroke/systemic thromboembolism in Japanese patients with non-valvular paroxysmal atrial fibrillation (NVPAF). We retrospectively investigated the incidence of ischemic stroke on the basis of CHADS2 and CHA2DS2-VASc scores in 332 NVPAF patients (224 men, mean age, 65 ± 13 years) who were not administered anticoagulation therapy before publication of the 2008 JCS guideline (mean follow-up period, 53 ± 35 months). Annual rates of ischemic stroke/ systemic thromboembolism underlying antiarrhythmic drug therapy were 0.2%/year for the 0-point group; 0.9%/year for the 1-point group; 2.8%/year for the 2-point group; 9.4 %/year for the 3-point group; and 10.9%/year for the ≥ 4-point group on the basis of the CHADS2 scores, and 0%/year for the 0-point group; 0.6%/year for the 1-point group; 1.0%/ year for the 2-point group; 2.0 %/year for the 3-point group; 5.5%/year for the 4-point group; 9.1%/year for the 5-point group; and 13.7%/year for the ≥ 6-point group on the basis of the CHA2DS2-VASc scores. Both higher CHADS2 and CHA2DS2-VASc scores were associated with greater annual rates of ischemic stroke/systemic thromboembolism (P < 0.001). In multivariate logistic regression analysis, the CHADS2 (odds ratio [OR]:4.74, 95% confidence interval [CI]:2.80-8.00, P < 0.001) and CHA2DS2-VASc scores (OR: 4.15, 95% CI:2.57-6.71, P < 0.001) were significant independent predictors for ischemic stroke/systemic thromboembolism. Area under the receiver-operator characteristic curves for predicting ischemic stroke/systemic thromboembolism were 0.89 in the CHA2DS2-VASc scores (P < 0.001) and 0.87 in the CHADS2 scores (P < 0.001). In Japanese patients with NVPAF, both the CHADS2 and CHA2DS2-VASc scores are useful parameters for the risk stratification of ischemic stroke/systemic thromboembolism.

Risk and protective factors in the origin of atrial septal defect secundum--national population-based case-control study.

The aim of this study was to assess the risk factors in the origin of lethal or surgically corrected isolated atrial septal defect secundum. The population-based Hungarian Case-Control Surveillance of Congenital Abnormalities (conducted between 1980 and 1996) comprised 472 atrial septal defect secundum cases, 678 matched controls and 38,151 available controls without any defects; in addition, 21,022 malformed controls with other isolated defects. Medically recorded chronic disorders in the prenatal maternity logbook were evaluated, while acute maternal diseases, drug treatments and pregnancy supplements were analyzed on the basis of both prospective medically recorded data and retrospective maternal information. Acute pelvic inflammatory disease, paroxysmal supraventricular tachycardia and phenolphthalein treatment due to severe constipation of mothers were shown to contribute to the development of atrial septal defect secundum of their children. High doses of folic acid in early pregnancy had positively influenced a minor part of isolated atrial septal defect secundum in foetuses. In conclusion, the obvious genetic predisposition for atrial septal defect secundum is connected with maternal paroxysmal supraventricular tachycardia and triggered by acute pelvic inflammatory diseases and phenolphthalein treatment, while the manifestation of atrial septal defect secundum can be reduced by high doses of folic acid supplementation in early pregnancy.

Paroxysmal supraventricular tachycardia and the risk of ischemic stroke.

BACKGROUND AND PURPOSE: It is unknown whether supraventricular arrhythmias other than atrial fibrillation or flutter are associated with stroke. METHODS: To examine the association between paroxysmal supraventricular tachycardia (PSVT) and stroke, we performed a retrospective cohort study using administrative claims data from all emergency department encounters and hospitalizations at California's nonfederal acute care hospitals in 2009. Our cohort comprised all adult patients with ≥ 1 emergency department visit or hospitalization from which they were discharged alive and without a diagnosis of stroke. Our primary exposure was a diagnosis of PSVT recorded at an encounter before stroke or documented as present-on-admission at the time of stroke. To reduce confounding, we excluded patients with diagnoses of atrial fibrillation. We defined PSVT, stroke, and atrial fibrillation using International Classification of Diseases, Ninth Revision, Clinical Modification codes previously validated by detailed chart review. RESULTS: Of 4 806 830 eligible patients, 14 121 (0.29%) were diagnosed with PSVT and 14 402 (0.30%) experienced a stroke. The cumulative rate of stroke after PSVT diagnosis (0.94%; 95% confidence interval, 0.76%-1.16%) significantly exceeded the rate among patients without a diagnosis of PSVT (0.21%; 95% confidence interval, 0.21%-0.22%). In Cox proportional hazards analysis controlling for demographic characteristics and potential confounders, PSVT was independently associated with a higher risk of subsequent stroke (hazard ratio, 2.10; 95% confidence interval, 1.69-2.62). CONCLUSIONS: In a large and demographically diverse sample of patients, we found an independent association between PSVT and ischemic stroke. PSVT seems to be a novel risk factor that may account for some proportion of strokes that are currently classified as cryptogenic.

[About military medical examination of patients with paroxysmal supraventricular reciprocating tachycardia].

140 patients with paroxysmal supraventricular reciprocating tachycardia were treated with the help of radio frequency ablation; results of treatment were analyzed. First group consisted of 76 patients with atrioventricular nodal reentrant tachycardia, second group--64 patients with atrioventricular reentrant tachycardia accompanied with WPW syndrome and preexcitation syndrome. In first group the operation ended up with success in 94.7%, in the second group--90.6%, after the second operation--100% and 96.1% relatively. Different complications in patients from the first group occured in 3.9%, in the second group--in 6.3%. Taking into account high effectivennes and safety of radio frequency ablation, it is recommended to reconsider principals of categorisation of fitness for service among conscripts and servicemen doing call-up and under the contract military service and also citizens, entering military educational institutions.

Delayed tamponade triggering Dressler's syndrome after pulmonary vein isolation.

Percutaneous catheter ablation is now a well-established, efficient and effective treatment strategy for recurrent, symptomatic atrial fibrillation (AF). Major complications though occur in up to 5.9% of procedures. New complications still continue to emerge. Delayed tamponade is only recently recognized as a major complication after ablation. We present a 68-year-old female patient who develops cardiac tamponade requiring pericardiocentesis 12 days after AF ablation. Subsequently, the tamponade triggers a Dressler syndrome with repetitive pleural effusions only adequately responsive to corticosteroids.

Prospective multicentric validation of a novel prediction model for paroxysmal atrial fibrillation.

BACKGROUND: The early recognition of paroxysmal atrial fibrillation (pAF) is a major clinical challenge for preventing thromboembolic events. In this prospective and multicentric study we evaluated prediction scores for the presence of pAF, calculated from non-invasive medical history and echocardiographic parameters, in patients with unknown AF status. METHODS: The 12-parameter score with parameters age, LA diameter, aortic root diameter, LV,ESD, TDI A', heart frequency, sleep apnea, hyperlipidemia, type II diabetes, smoker, ß-blocker, catheter ablation, and the 4-parameter score with parameters age, LA diameter, aortic root diameter and TDI A' were tested. Presence of pAF was verified by continuous electrocardiogram (ECG) monitoring for up to 21 days in 305 patients. RESULTS: The 12-parameter score correctly predicted pAF in all 34 patients, in which pAF was newly detected by ECG monitoring. The 12- and 4-parameter scores showed sensitivities of 100% and 82% (95%-CI 65%, 93%), specificities of 75% (95%-CI 70%, 80%) and 67% (95%-CI 61%, 73%), and areas under the receiver operating characteristic (ROC) curves of 0.84 (95%-CI 0.80, 0.88) and 0.81 (95%-CI 0.74, 0.87). Furthermore, properties of AF episodes and durations of ECG monitoring necessary to detect pAF were analysed. CONCLUSIONS: The prediction scores adequately detected pAF using variables readily available during routine cardiac assessment and echocardiography. The model scores, denoted as ECHO-AF scores, represent simple, highly sensitive and non-invasive tools for detecting pAF that can be easily implemented in the clinical practice and might serve as screening test to initiate further diagnostic investigations for validating the presence of pAF. Prospective validation of a novel prediction model for paroxysmal atrial fibrillation based on echocardiography and medical history parameters by long-term Holter ECG.

Treatment of paroxysmal supraventricular tachycardia using instrument-assisted manipulation of the fourth rib: a 6-year case study.

OBJECTIVE: The purpose of this case report was to describe the observation of the manipulation of the fourth rib followed by the reproducible, rapid return of heart rate to normal in a patient with paroxysmal supraventricular tachycardia. CLINICAL FEATURES: A male patient had paroxysmal supraventricular tachycardia. He was evaluated using standard methods of palpation. He was followed over a 6-year period. INTERVENTION AND OUTCOME: The patient was treated during episodes of supraventricular tachycardia (SVT) with instrument-assisted manipulation of the fourth rib without treatment of any other segments. Tachycardia was eliminated after rib manipulation within less than 2 minutes. Over a 6-year period, effective control of episodes of SVT was consistently achieved associated with manipulation of the fourth rib. CONCLUSIONS: This case study is suggestive of a relationship between SVT and misalignment of the fourth rib. Controlled studies are necessary to validate this observation.

Clozapine-related Paroxysmal Supraventricular Tachycardia: a Case Report.

Clozapine is considered to be more effective than other antipsychotic drugs for treating treatmentresistant schizophrenia. However, side effects of clozapine include agranulocytosis and, less commonly, cardiovascular disease, which is occasionally fatal. We describe a 56-year-old woman who developed clozapine-related paroxysmal supraventricular tachycardia during clozapine dose titration and had a recurrence despite being treated with verapamil. For treatment-resistant schizophrenia, a slow titration of the clozapine dose is necessary, and potential cardiac side-effects should be monitored.

Association of Burden of Atrial Fibrillation With Risk of Ischemic Stroke in Adults With Paroxysmal Atrial Fibrillation: The KP-RHYTHM Study.

Importance: Atrial fibrillation is a potent risk factor for stroke, but whether the burden of atrial fibrillation in patients with paroxysmal atrial fibrillation independently influences the risk of thromboembolism remains controversial. Objective: To determine if the burden of atrial fibrillation characterized using noninvasive, continuous ambulatory monitoring is associated with the risk of ischemic stroke or arterial thromboembolism in adults with paroxysmal atrial fibrillation. Design, Setting, and Participants: This retrospective cohort study conducted from October 2011 and October 2016 at 2 large integrated health care delivery systems used an extended continuous cardiac monitoring system to identify adults who were found to have paroxysmal atrial fibrillation on 14-day continuous ambulatory electrocardiographic monitoring. Exposures: The burden of atrial fibrillation was defined as the percentage of analyzable wear time in atrial fibrillation or flutter during the up to 14-day monitoring period. Main Outcomes and Measures: Ischemic stroke and other arterial thromboembolic events occurring while patients were not taking anticoagulation were identified through November 2016 using electronic medical records and were validated by manual review. We evaluated the association of the burden of atrial fibrillation with thromboembolism while not taking anticoagulation after adjusting for the Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) or CHA2DS2-VASc stroke risk scores. Results: Among 1965 adults with paroxysmal atrial fibrillation, the mean (SD) age was 69 (11.8) years, 880 (45%) were women, 496 (25%) were persons of color, the median ATRIA stroke risk score was 4 (interquartile range [IQR], 2-7), and the median CHA2DS2-VASc score was 3 (IQR, 1-4). The median burden of atrial fibrillation was 4.4% (IQR ,1.1%-17.23%). Patients with a higher burden of atrial fibrillation were less likely to be women or of Hispanic ethnicity, but had more prior cardioversion attempts compared with those who had a lower burden. After adjusting for either ATRIA or CHA2DS2-VASc stroke risk scores, the highest tertile of atrial fibrillation burden (≥11.4%) was associated with a more than 3-fold higher adjusted rate of thromboembolism while not taking anticoagulants (adjusted hazard ratios, 3.13 [95% CI, 1.50-6.56] and 3.16 [95% CI, 1.51-6.62], respectively) compared with the combined lower 2 tertiles of atrial fibrillation burden. Results were consistent across demographic and clinical subgroups. Conclusions and Relevance: A greater burden of atrial fibrillation is associated with a higher risk of ischemic stroke independent of known stroke risk factors in adults with paroxysmal atrial fibrillation.

Progression of paroxysmal atrial fibrillation to persistent atrial fibrillation in patients with bradyarrhythmias.

INTRODUCTION: The experimental concept that "atrial fibrillation (AF) begets AF" implies that atrial tachyarrhythmia (AT)/AF burden uniformly increases over time. However, the temporal patterns of paroxysmal AT/AF burden progression, its conversion to persistent AF, and the relationship to underlying disease in humans are unknown. We analyzed the average daily AT/AF burden in patients with concomitant bradycardia and paroxysmal AF to examine these issues. METHODS: Three hundred thirty patients with a history of paroxysmal AF (mean age 70 +/- 10 years; 61% male) were implanted with a pacemaker that automatically recorded the cumulative daily AT/AF burden. Persistent AT/AF was defined as 7 consecutive days with >23 hours of AT on the device data logs. Antiarrhythmic drug therapy was required to be stable for at least 7 months. RESULTS: Average follow-up was 401 +/- 123 days. Seventy-eight patients (24%) progressed to persistent AT/AF during the follow-up period with a mean interval of 147 +/- 149 days. Mean AT/AF burden increased progressively (slope 14 s/d, P < .001) over 500 days after implant, and median AT/AF burden also increased (P < .01) in this subgroup of patients. This increase was highly correlated with the presence of structural heart disease (P < .001). There was a concomitant decrease in atrial premature beat (APB) frequency. Most patients transitioning to persistent AF were in sinus rhythm with minimal AT/AF burden in the days immediately before persistent AF. Neither mean nor median AT/AF burden increased over time in patients remaining in paroxysmal AF (slope 0 s/d, P = .7) despite a higher APB frequency than in patients with heart disease (P =.003) and a higher likelihood of daily AT/AF events (P < .001). CONCLUSIONS: Temporal patterns of AT/AF burden in patients developing persistent AF show a progressive increase with a sudden transition to persistent AF. This is more consistent with substrate changes, rather than increased density of triggering APBs or paroxysmal AT/AF events. Thus, progression to persistent AF is probably related to an AF substrate, which is undergoing progressive structural remodeling owing to heart disease and other factors and is now suddenly capable of sustaining prolonged or multiple ATs. Therapies directed at the atrial substrate may be needed to prevent persistent AF.