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Background Abnormalities in left atrial (LA) function often occur before LA structural changes and clinically identified atrial fibrillation (AF). Little is known about the relationship between LA strain and the risk of subclinical atrial arrhythmias detected from extended ambulatory cardiac monitoring. Methods and Results A total of 1441 participants of MESA (Multi‐Ethnic Study of Atherosclerosis) completed speckle‐tracking echocardiography and cardiac monitoring during 2016 to 2018 (mean age, 73 years); participants in AF during echocardiography or during the entire cardiac monitoring period were excluded. Absolute values of LA reservoir, booster pump, and conduit strains were measured. We evaluated associations of LA strain with monitor‐detected AF, premature atrial contractions, and supraventricular tachycardia. Primary analyses adjusted for demographic variables, blood pressure, diabetes, smoking, and clinical cardiovascular disease. Cardiac monitoring (median, 14 days) detected AF in 3%. Each SD (4.0%) lower (worse) LA booster pump strain was associated with 84% higher risk of monitor‐detected AF (95% CI, 30%–162%), 39% higher premature atrial contraction frequency (95% CI, 27%–53%), and 19% higher supraventricular tachycardia frequency (95% CI, 10%–29%). Additional adjustment for NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide), LA volume index, tissue Doppler a′ peak velocity, left ventricular ejection fraction, and global longitudinal strain had little impact on associations. Findings were similar for LA reservoir strain and null for LA conduit strain. Conclusions In a multiethnic community‐based cohort, impaired LA strain was an important correlate of subclinical atrial arrhythmias, even after adjustment for conventional measures of LA structure and function.

BackgroundSubclinical atrial fibrillation (AF) is one of the pathogeneses of embolic stroke. Detection of occult AF and providing proper anticoagulant treatment is an important way to prevent stroke recurrence. The purpose of this study was to determine whether an artificial intelligence (AI) model can assess occult AF using 24-h Holter monitoring during normal sinus rhythm.MethodsThis study is a retrospective cohort study that included those who underwent Holter monitoring. The primary outcome was identifying patients with AF analyzed with an AI model using 24-h Holter monitoring without AF documentation. We trained the AI using a Holter monitor, including supraventricular ectopy (SVE) events (setting 1) and excluding SVE events (setting 2). Additionally, we performed comparisons using the SVE burden recorded in Holter annotation data.ResultsThe area under the receiver operating characteristics curve (AUROC) of setting 1 was 0.85 (0.83–0.87) and that of setting 2 was 0.84 (0.82–0.86). The AUROC of the SVE burden with Holter annotation data was 0.73. According to the diurnal period, the AUROCs for daytime were 0.83 (0.78–0.88) for setting 1 and 0.83 (0.78–0.88) for setting 2, respectively, while those for nighttime were 0.85 (0.82–0.88) for setting 1 and 0.85 (0.80–0.90) for setting 2.ConclusionWe have demonstrated that an AI can identify occult paroxysmal AF using 24-h continuous ambulatory Holter monitoring during sinus rhythm. The performance of our AI model outperformed the use of SVE burden in the Holter exam to identify paroxysmal AF. According to the diurnal period, nighttime recordings showed more favorable performance compared to daytime recordings.

Background: Friedreich ataxia is the most commonly inherited ataxia; nearly 60% of deaths are cardiac in nature, with one in eight deaths due to arrhythmia. Additional or irregular heartbeats, measured as ectopy, can be quantified using portable heart rhythm monitoring. We sought to describe the ectopic burden in Friedreich ataxia.Methods: Using a natural history study of patients with Friedreich ataxia at a single center, we analyzed portable heart rhythm monitors (Holters). Ectopic burden was defined as the proportion of atrial or ventricular ectopic beats over total beats.Results: Of 456 patients, 131 had Holters. Sixty-eight (52.0%) were male, median age of symptom onset was 8.0 years (5.0 to 13.0, n = 111), median age at time of Holter was 17.3 years (interquartile range [IQR] 12.9 to 22.8, n = 129), and median duration of illness was 8.7 years (IQR 5.3 to 11.6, n = 110). Median GAA length on the shorter FXN allele was 706.0 (IQR 550.0 to 840.0, n = 112). Eight (7.8%, n = 103) had diminished cardiac function, and 74 (74.0%, n = 100) had ventricular hypertrophy. Ninety patients (83.0%) had atrial ectopy (supraventricular ectopy [SVE]): 85 (78.0%) with rare SVE (>0% to 5%) and five (5.0%) with frequent SVE (>10%). Twenty-five (19.0%) had supraventricular runs, and one (0.8%) had atrial fibrillation/flutter. Forty-five (41.0%) had ventricular ectopy (VE): 43 (39.0%) with rare VE (0% to 5%) and two (2.0%) with moderate VE (5% to 10%). Compared with patients with none and rare SVE, patients with frequent SVE had longer disease duration (18.3 versus 4.6 versus 9.0 years, P = 0.0005).Conclusion: Patients with longer disease duration had higher rates of SVE. Heart rhythm monitoring may be considered for risk stratification; however, longitudinal analysis is needed. [ABSTRACT FROM AUTHOR]

Background High levels of supraventricular ectopy are associated with greater risk of atrial fibrillation, stroke, and death. Little information is available about differences by race/ethnicity in the extent of supraventricular ectopy, or about whether high levels of supraventricular ectopy are associated with impaired left atrial (LA) function and LA enlargement. Methods and Results In the MESA (Multi‐Ethnic Study of Atherosclerosis), 1148 participants (47% men; mean age, 67 years) had cardiovascular magnetic resonance imaging in 2010 to 2012, followed by 14‐day ambulatory electrocardiographic monitoring in 2016 to 2018. We analyzed participant characteristics and cardiovascular magnetic resonance measures of LA function and structure in relation to average count of premature atrial contractions (PACs) per hour and average number of runs per day of supraventricular tachycardia. In adjusted regression analyses, older age, male sex, White race, elevated NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide), and a history of clinically detected atrial fibrillation were associated with more PACs/hour. Chinese and Hispanic participants had on average fewer PACs/hour than White participants (Chinese participants, 31% less [95% CI, 8%–49%]; Hispanic participants, 38% less [95% CI, 19%–52%]). Greater LA total emptying fraction was associated with fewer PACs/hour (per SD, 16% fewer PACs/hour [95% CI, 7%–25% fewer PACs/hour]). Larger LA minimum volume was associated with more PACs/hour (per SD, 7% more PACs/hour [95% CI, 2%–13% more PACs/hour]). Associations of LA volumes with runs of supraventricular tachycardia/day were similar in direction but were weaker. Conclusions Impaired LA function and LA enlargement were associated with more PACs/hour on extended ambulatory electrocardiographic monitoring. Measurement of supraventricular ectopy may provide information about the extent of atrial myopathy.

Background: Patch electrocardiographic (ECG) monitors permit extended noninvasive ambulatory monitoring. To guide use of these devices, information is needed about their performance. We sought to determine in a large general population sample the acceptability of patch ECG monitors, the yield of arrhythmia detection, and the consistency of findings in participants monitored twice.Methods: In the Multi-Ethnic Study of Atherosclerosis, 1122 participants completed one or two monitoring episodes using the Zio Patch XT, a single-channel ECG patch monitor capable of recording for 14 days. Recordings were analyzed for atrial fibrillation (AF), atrial flutter, atrioventricular block, pauses, and supraventricular and ventricular ectopy.Results: The mean(SD) age at the time of monitoring was 75(8) years, 52% were men, and 15% had a prior history of clinically-recognized AF/flutter. The median monitoring duration was 13.8 days. Among 804 participants with no prior clinical history of AF/flutter and at least 12 days of monitoring on a single device, AF/flutter was detected in 32 (4.0%); in 38% of these, AF/flutter was first detected during days 3 through 12 of monitoring. In participants monitored twice, findings from the two devices showed excellent agreement for supraventricular and ventricular ectopic beats per hour, but only fair agreement for high-grade atrioventricular block and pauses of >3 s duration.Conclusions: In a general population of older individuals, new diagnoses of AF/flutter were made in 4.0% of participants without a prior history. A single monitoring episode accurately estimated rates of supraventricular and ventricular ectopy. [ABSTRACT FROM AUTHOR]

Background Abnormalities in left atrial (LA) function often occur before LA structural changes and clinically identified atrial fibrillation (AF). Little is known about the relationship between LA strain and the risk of subclinical atrial arrhythmias detected from extended ambulatory cardiac monitoring. Methods and Results A total of 1441 participants of MESA (Multi-Ethnic Study of Atherosclerosis) completed speckle-tracking echocardiography and cardiac monitoring during 2016 to 2018 (mean age, 73 years); participants in AF during echocardiography or during the entire cardiac monitoring period were excluded. Absolute values of LA reservoir, booster pump, and conduit strains were measured. We evaluated associations of LA strain with monitor-detected AF, premature atrial contractions, and supraventricular tachycardia. Primary analyses adjusted for demographic variables, blood pressure, diabetes, smoking, and clinical cardiovascular disease. Cardiac monitoring (median, 14 days) detected AF in 3%. Each SD (4.0%) lower (worse) LA booster pump strain was associated with 84% higher risk of monitor-detected AF (95% CI, 30%-162%), 39% higher premature atrial contraction frequency (95% CI, 27%-53%), and 19% higher supraventricular tachycardia frequency (95% CI, 10%-29%). Additional adjustment for NT-proBNP (N-terminal pro-B-type natriuretic peptide), LA volume index, tissue Doppler a' peak velocity, left ventricular ejection fraction, and global longitudinal strain had little impact on associations. Findings were similar for LA reservoir strain and null for LA conduit strain. Conclusions In a multiethnic community-based cohort, impaired LA strain was an important correlate of subclinical atrial arrhythmias, even after adjustment for conventional measures of LA structure and function.

Background: Subclinical atrial fibrillation (AF) is one of the pathogeneses of embolic stroke. Detection of occult AF and providing proper anticoagulant treatment is an important way to prevent stroke recurrence. The purpose of this study was to determine whether an artificial intelligence (AI) model can assess occult AF using 24-h Holter monitoring during normal sinus rhythm., Methods: This study is a retrospective cohort study that included those who underwent Holter monitoring. The primary outcome was identifying patients with AF analyzed with an AI model using 24-h Holter monitoring without AF documentation. We trained the AI using a Holter monitor, including supraventricular ectopy (SVE) events (setting 1) and excluding SVE events (setting 2). Additionally, we performed comparisons using the SVE burden recorded in Holter annotation data., Results: The area under the receiver operating characteristics curve (AUROC) of setting 1 was 0.85 (0.83-0.87) and that of setting 2 was 0.84 (0.82-0.86). The AUROC of the SVE burden with Holter annotation data was 0.73. According to the diurnal period, the AUROCs for daytime were 0.83 (0.78-0.88) for setting 1 and 0.83 (0.78-0.88) for setting 2, respectively, while those for nighttime were 0.85 (0.82-0.88) for setting 1 and 0.85 (0.80-0.90) for setting 2., Conclusion: We have demonstrated that an AI can identify occult paroxysmal AF using 24-h continuous ambulatory Holter monitoring during sinus rhythm. The performance of our AI model outperformed the use of SVE burden in the Holter exam to identify paroxysmal AF. According to the diurnal period, nighttime recordings showed more favorable performance compared to daytime recordings., Competing Interests: KK, YT, MC, and YL were employed by VUNO Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kim, Kim, Tae, Chang, Park, Park, On, Kim, Lee and Jang.)

Aims Paroxysmal atrial fibrillation (AF) is usually preceded by a premature atrial complex (PAC). We hypothesized that patients with a high frequency of atrial ectopic activity after restoration of sinus rhythm following direct current cardioversion would be more likely to experience recurrence of AF. [ABSTRACT FROM PUBLISHER]

Objective: Adult beta-thalassemia major (TM) patients exhibit electrocardiographic abnormalities and cardiac autonomic dysfunction. We aimed to investigate the evolution of electrocardiographic abnormalities and arrhythmias in TM patients during a 12-month follow-up period., Methods: Forty-seven adult TM patients (median age: 36 years, 57% men) without overt heart failure were studied. We examined 12-lead electrocardiograms, 24-hour electrocardiographic Holter recordings, and treadmill exercise stress tests at baseline and after 12 months. Conventional electrocardiographic measurements, as well as contemporary indexes of depolarization and repolarization/dispersion of repolarization (QRS fragmentation; T peak-to-end; T peak-to-end/QT) were assessed. Moreover, we examined markers of autonomic dysfunction such as heart rate variability, and heart rate recovery after exercise testing., Results: The electrocardiographic markers of atrial/ventricular depolarization and repolarization, as well as indexes of autonomic imbalance, were not significantly changed. However, the recorded supraventricular ectopic beats increased significantly. Paroxysmal atrial fibrillation (PAF) detection was greater in 12 months (4/47 at baseline vs. 8/47 at 12 months; P=0.38). However, 5/8 patients who were diagnosed with PAF at the second examination did not have the arrhythmia at the initial evaluation. Thus, PAF was present in a total of 9/47 (19%) TM patients. Notably, 3/9 of the patients were asymptomatic. The mean duration of PAF was 5±2 minutes and the mean number of these episodes was 8±2., Conclusion: TM patients have repolarization and autonomic function abnormalities that do not significantly change during a 12-month follow-up period. However, supraventricular ectopy and AF burden further evolve., Competing Interests: None., (AJCD Copyright © 2021.)

Background High levels of supraventricular ectopy are associated with greater risk of atrial fibrillation, stroke, and death. Little information is available about differences by race/ethnicity in the extent of supraventricular ectopy, or about whether high levels of supraventricular ectopy are associated with impaired left atrial (LA) function and LA enlargement. Methods and Results In the MESA (Multi-Ethnic Study of Atherosclerosis), 1148 participants (47% men; mean age, 67 years) had cardiovascular magnetic resonance imaging in 2010 to 2012, followed by 14-day ambulatory electrocardiographic monitoring in 2016 to 2018. We analyzed participant characteristics and cardiovascular magnetic resonance measures of LA function and structure in relation to average count of premature atrial contractions (PACs) per hour and average number of runs per day of supraventricular tachycardia. In adjusted regression analyses, older age, male sex, White race, elevated NT-proBNP (N-terminal pro-B-type natriuretic peptide), and a history of clinically detected atrial fibrillation were associated with more PACs/hour. Chinese and Hispanic participants had on average fewer PACs/hour than White participants (Chinese participants, 31% less [95% CI, 8%-49%]; Hispanic participants, 38% less [95% CI, 19%-52%]). Greater LA total emptying fraction was associated with fewer PACs/hour (per SD, 16% fewer PACs/hour [95% CI, 7%-25% fewer PACs/hour]). Larger LA minimum volume was associated with more PACs/hour (per SD, 7% more PACs/hour [95% CI, 2%-13% more PACs/hour]). Associations of LA volumes with runs of supraventricular tachycardia/day were similar in direction but were weaker. Conclusions Impaired LA function and LA enlargement were associated with more PACs/hour on extended ambulatory electrocardiographic monitoring. Measurement of supraventricular ectopy may provide information about the extent of atrial myopathy.