Frequent Premature Contractions Research Articles

Fetal premature atrial contractions: natural course, risk factors and adverse outcome.

Fetal premature atrial contractions (PAC) are usually benign but may be associated with congenital heart defect (CHD) and tachyarrhythmia, which in turn carry a risk of cardiac failure and fetal death. We aimed to explore the frequency of adverse outcome and to identify risk factors for tachyarrhythmia in pregnancies complicated by fetal PAC. This was a retrospective cohort study of fetuses diagnosed with PAC at two academic centers in Amsterdam, The Netherlands, between 2007 and 2022. Cases with a congenital anomaly and those with a prior diagnosis of CHD or other arrhythmias were excluded. M-mode and Doppler tracings were reanalyzed and the frequency of PAC was recorded. The incidence of the following adverse outcomes was examined: underlying CHD not identified at the 20-week fetal anomaly scan, tachyarrhythmia, other arrhythmia, administration of antiarrhythmic therapy and death. Risk factors for tachyarrhythmia were analyzed using odds ratios (OR). In 24.1% of 1439 referred cases, PAC resolved before confirmation at the fetal medicine unit (FMU). Of the 939 included cases with confirmed PAC, the total incidence of adverse outcome was 6.8% (64/939). CHD was diagnosed in 14 (1.5% (95% CI, 0.9-2.5%)) cases, of which eight were diagnosed prenatally and six postnatally. Compared with baseline, the incidence of CHD was higher in the presence of fetal PAC (OR, 1.8 (95% CI, 1.0-3.3); P = 0.034). Tachyarrhythmia occurred prenatally and/or postnatally in 32 (3.4%) cases, of which eight (25.0%) showed signs of cardiac failure, and in 23 (71.9%) cases, antiarrhythmic therapy was required. No cases of tachyarrhythmia led to fetal or infant death. Risk factors for tachyarrhythmia were PAC with short runs of supraventricular tachycardia (OR, 98.7), blocked PAC (OR, 30.3), PAC in bigeminy (OR, 21.8), frequent PAC (one per 5-10 beats) (OR, 6.9), signs of cardiac failure (OR, 14.2) and the presence of a foramen ovale aneurysm (OR, 5.0). PAC are generally benign and often resolve spontaneously. However, fetuses with an irregular heart rhythm should be referred for advanced ultrasonography, which should focus on classifying the type of PAC and risk of adverse outcome. When risk factors for tachyarrhythmia are identified, weekly fetal heart-rate monitoring is advised until resolution of the PAC. In the absence of risk factors, standard obstetric care may be sufficient, with additional instructions to report reduced fetal movements. Should tachyarrhythmia or cardiac failure develop, referral back to the FMU is indicated. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Higher Frequency of Premature Atrial Contractions Correlates With Atrial Fibrillation Detection after Cryptogenic Stroke.

Covert atrial fibrillation (AF) is a major cause of cryptogenic stroke. This study investigated whether a dose-dependent relationship exists between the frequency of premature atrial contractions (PACs) and AF detection in patients with cryptogenic stroke using an insertable cardiac monitor (ICM). We enrolled consecutive patients with cryptogenic stroke who underwent ICM implantation between October 2016 and September 2020 at 8 stroke centers in Japan. Patients were divided into 3 groups according to the PAC count on 24-hour Holter ECG: ≤200 (group L), >200 to ≤500 (group M), and >500 (group H). We defined a high AF burden as above the median of the cumulative duration of AF episodes during the entire monitoring period. We evaluated the association of the frequency of PACs with AF detection using log-rank trend test and Cox proportional hazard model and with high AF burden using logistic regression model, adjusting for age, sex, CHADS2 score. Of 417 patients, we analyzed 381 patients with Holter ECG and ICM data. The median age was 70 (interquartile range, 59.5-76.5), 246 patients (65%) were males, and the median duration of ICM recording was 605 days (interquartile range, 397-827 days). The rate of new AF detected by ICM was higher in groups with more frequent PAC (15.5%/y in group L [n=277] versus 44.0%/y in group M [n=42] versus 71.4%/y in group H [n=62]; log-rank trend P<0.01). Compared with group L, the adjusted hazard ratios for AF detection in groups M and H were 2.11 (95% CI, 1.24-3.58) and 3.23 (95% CI, 2.07-5.04), respectively, and the adjusted odds ratio for high AF burden in groups M and H were 2.57 (95% CI, 1.14-5.74) and 4.25 (2.14-8.47), respectively. The frequency of PACs was dose-dependently associated with AF detection in patients with cryptogenic stroke.

Frequent Premature Atrial Contractions Lead to Adverse Atrial Remodeling and Atrial Fibrillation in a Swine Model.

Frequent premature atrial complexes (PACs) are associated with future incident atrial fibrillation (AF), but whether PACs contribute to development of AF through adverse atrial remodeling has not been studied. This study aimed to explore the effect of frequent PACs from different sites on atrial remodeling in a swine model. Forty swine underwent baseline electrophysiologic studies and echocardiography followed by pacemaker implantations and paced PACs (50% burden) at 250-ms coupling intervals for 16 weeks in 4 groups: (1) lateral left atrium (LA) PACs by the coronary sinus (Lat-PAC; n=10), (2) interatrial septal PACs (Sep-PAC; n=10), (3) regular LA pacing at 130 beats/min (Reg-130; n=10), and (4) controls without PACs (n=10). At the final study, repeat studies were performed, followed by tissue histology and molecular analyses focusing on fibrotic pathways. Lat-PACs were associated with a longer P-wave duration (93.0±9.0 versus 74.2±8.2 and 58.8±7.6 ms; P<0.001) and greater echocardiographic mechanical dyssynchrony (57.5±11.6 versus 35.7±13.0 and 24.4±11.1 ms; P<0.001) compared with Sep-PACs and controls, respectively. After 16 weeks, Lat-PACs led to slower LA conduction velocity (1.1±0.2 versus 1.3±0.2 [Sep-PAC] versus 1.3±0.1 [Reg-130] versus 1.5±0.2 [controls] m/s; P<0.001) without significant change in atrial ERP. The Lat-PAC group had a significantly increased percentage of LA fibrosis and upregulated levels of extracellular matrix proteins (lysyl oxidase and collagen 1 and 8), as well as TGF-β1 (transforming growth factor-β1) signaling proteins (latent and monomer TGF-β1 and phosphorylation/total ratio of SMAD2/3; P<0.05). The Lat-PAC group had the longest inducible AF duration (terminal to baseline: 131 [interquartile range 30, 192] seconds versus 16 [6, 26] seconds [Sep-PAC] versus 22 [11, 64] seconds [Reg-130] versus -1 [-16, 7] seconds [controls]; P<0.001). In this swine model, frequent PACs resulted in adverse atrial structural remodeling with a heightened propensity to AF. PACs originating from the lateral LA produced greater atrial remodeling and longer induced AF duration than the septal-origin PACs. These data provide evidence that frequent PACs can cause adverse atrial remodeling as well as AF, and that the location of ectopic PACs may be clinically meaningful.

Efficacy and safety of Saireito (TJ-114) in patients with atrial fibrillation undergoing catheter ablation procedures: A randomized pilot study.

Early arrhythmia recurrences commonly occur after atrial fibrillation (AF) ablation because of irritability and inflammation of left atrium. We hypothesized that short-term use of Saireito would be effective in reducing frequent atrial tachyarrhythmias in the early-phase post-ablation. One hundred patients undergoing catheter ablation for symptomatic AF were randomly assigned to either a 30-day use of Saireito or control group. The primary endpoint was total number of episodes of frequent atrial tachyarrhythmias including definite recurrent AF and frequent premature atrial contractions during the 30-day treatment period post-ablation. Three (6.0%) out of 50 patients treated with Saireito discontinued the drug because of adverse symptoms. The Saireito group was associated with a numerically lower number of episodes of frequent atrial tachyarrhythmias than the control group (3.1 versus 5.2 times, P = 0.17). The mean daily episodes of frequent atrial tachyarrhythmias were significantly fewer in the Saireito group during Day-6 to Day-10 (0.12/day versus 0.27/day, P = 0.03), and during Day-11 to Day-15 (0.08/day versus 0.24/day, P = 0.001). The prevalence of adverse symptoms during the 30-day treatment period was significantly higher in the Saireito group (18.0% versus 2.0%, P = 0.005). Thirty-day use of Saireito following AF ablation was associated with a tendency toward reduced number of episodes of frequent atrial tachyarrhythmias during the treatment period, with more pronounced effect in the first two weeks.

Snoring and lack of REM sleep is associated with same-day atrial arrhythmias in a cohort of patients with atrial fibrillation: initial results of TriggersAF

Abstract Introduction Sleep-disordered breathing (SDB) is a known risk factor for the development of atrial fibrillation (AF). Few studies analyse the temporal relation between snoring, sleep phases and atrial arrhythmia episodes. Purpose The TriggersAF trial (NCT05526170) investigates the temporal relation between atrial arrhythmias and potential triggers. In this preliminary analysis, the authors hypothesised that snoring and disturbance of sleep phases may be associated with same-day atrial arrhythmias. Methods In a single-centre prospective cohort study patients with previously diagnosed AF were recruited for home monitoring of 7 days. A single-lead continuous electrocardiogram (ECG) of the reference Holter monitor (Bittium, Kuopio, Finland) documented the cardiac rhythm. The recordings were manually annotated as: 1) AF, 2) atrial tachycardia or flutter (AT), 3) frequent premature atrial contractions (PAC), defined as bigeminy, trigeminy, quadrigeminy or couplets, and 4) no arrhythmia. Sleep disorders were evaluated using a validated sleep tracking mat (Withings Sleep Analyzer, Issy-les-Moulineaux, France) and described by the number of snoring episodes, durations of snoring, light, deep, and rapid-eye-movement (REM) phases. Heart echocardiography with strain imaging of left atrium (LA) was performed to further characterize the subjects. Results The study consisted of 49 patients, aged 55.8±11.7 years, 67.3% male. All patients were with previously diagnosed non-permanent AF and sinus rhythm at the moment of inclusion. The monitoring duration yielded a total of 300 days. The occurrence of AF, AT and PAC was detected in 32/300, 108/300 and 85/300 of days, respectively. As revealed by the sleep analysis a greater number of snoring episodes was associated with the same-day episodes of AF when compared to patients with no AF (5.0 (2-10.2) vs. 2.0 (0-7), P=0.029, respectively). A longer snoring duration was associated with the same-day episodes of AF (36 (6-80) min vs. 12 (0-52) min, P=0.057). A shorter duration of the REM phase was associated with AT (63 (28-93) min vs. 79 (42-105) min, P=0.032) and PAC (60 (32-91) min vs. 79 (37-102) min, P= 0.058). No significant relations were observed between the durations of light or deep phases and any type of arrhythmias. A smaller mean conduit strain of LA was highly associated with AF (-7,5 (-12,5, -7,5)) compared to patients with no AF (-11,0 (-14,8, -8,5), P= 0.002). In the Fast-and-Frugal Decision Tree for the prediction of same-day AF, a model combining the mean conduit strain of less than -9, a body mass index of more than 27.8, and a snoring duration of more than 29 minutes yielded a sensitivity of 97%, a specificity of 59% and a balanced accuracy of 78%. Conclusions The higher frequency and duration of snoring, as well as reduced REM phase of sleep are linked to same-day atrial arrhythmias. Long-term SDB monitoring and LA strain imaging predict the episodes of AF with high accuracy.Number of snoring episodes vs. AFAF by LA strain, BMI and snoring

Abstract 16671: Supraventricular Ectopic Activity Predicts Postoperative Atrial Fibrillation, New-Onset Atrial Fibrillation, and Worse Survival in Hypertrophic Cardiomyopathy

Introduction: Supraventricular ectopic activity (SEA), in the form of frequent premature atrial contractions (PACs) and runs of PACs, has been considered a marker of foci that are capable of firing rapidly to initiate atrial fibrillation (AF), but the cut-off value has not been determined. Therefore, we aimed to examine the association between SEA and postoperative AF (POAF) and clinical outcomes and to investigate the cut-off value in patients with hypertrophic cardiomyopathy. Methods: This cohort included 1491 consecutively recruited patients, of which 530 were excluded for various reasons, leaving 961 patients for final analysis. All patients received 24-hour Holter ECG monitoring 2-5 days before surgery. Results: The mean age of the study population was 48.4 (SD,12.3) years and 397 patients (41.3%) were female. The incidence of POAF was 20.7% and increased with PACs severity. Multivariable logistic regression analysis showed that supraventricular tachycardia (SVT) was independently associated with higher incidence of POAF and the model including SVT had the largest area under the curve (AUC) [AUC=0.710] among all the multivariable models. Furthermore, Kaplan-Meier survival curves demonstrated that patients in the tertile 3 (upper tertile of the total numbers of PACs), PACs&gt;100, PACs &gt;200, ESVEA (top decile of PACs plus top decile length of short atrial runs), and ESVEA3 (PACs&gt;100 plus top decile length of short atrial runs) group had significantly higher cumulative rates of new-onset AF and composite endpoints compared to their counterparts. On multivariable Cox regression analysis, PACs&gt; 100, PACs&gt;200, ESVEA, and ESVEA3 were independent indicators for higher incidence of new-onset AF and composite endpoints. Among those multivariate models, PACs &gt;200 had the higher effect size for predicting new-onset AF [Hazard ratio (HR) 3.13, 95% confidence interval (CI) 1.74-5.62] and composite endpoints [HR =2.00, 95%CI 1.30-3.06]. Conclusions: The incidence of POAF was 20.7% increasing with the severity of the PACs burden. Moreover, among supraventricular arrhythmias, SVT was the best indicator for predicting POAF. Likewise, PACs&gt;200 may consider as the best candidate for predicting a higher incidence of new-onset AF and composite endpoints.

FRI500 Atypical Case Of Undifferentiated Shock

Abstract Disclosure: V. Vadini: None. P. Vasistha: None. Introduction: Shock is encountered frequently in the ICU. Undifferentiated shock, however, poses a diagnostic challenge. The differentials and work up are broad and time sensitive. Endocrinopathies are a known etiology but thyroid cardiomyopathy causing cardiogenic shock is rare. Clinical case: A 78 y old man presented to the ER with hypotension that did not improve after administration of 2.5 L IV fluids. Vasopressors were initiated and he was admitted to the ICU. Patient reported 2-month history of generalized weakness, nausea, vomiting, falls and poor oral intake. Review of systems was notable for 20-pound weight loss in 6 months, dyspnea with exertion, loss of appetite and occasional diarrhea. On exam, patient was afebrile, hypotensive 80/40, PR 87, O2 saturation &amp;gt; 90% on room air. He appeared pale with JVP measured at 11 cm of water. Pulse was irregular, heart sounds normal without murmurs. Bilateral lower extremities were mildly edematous. Strength in lower extremities was 4/5 proximal and distally. Labs were notable for normocytic anemia, troponin 1.05, elevated anion gap 18, lactate 1.8, creatinine 3.3 from a baseline of 1 and BNP 1425. ECG showed sinus rhythm with frequent premature atrial contractions. Chest Xray on admission was unremarkable. Additional labs were negative drug screen, normal cortisol, urinalysis. Blood cultures were sent. Overnight, the patient developed tachycardia and atrial fibrillation with rapid ventricular rate. Cardiology was consulted, bedside echo was suspicious for low left ventricular ejection fraction. The patient was anticoagulated with heparin. TSH was sent. He was requiring 2 vasopressors to maintain MAP&amp;gt;65. CT chest abdomen pelvis was unremarkable except stable pulmonary nodule. Patient became hypoxic on Day 2 of admission, CXR now showed features of pulmonary edema. TSH returned less than 0.01, free T4 4.69 Endocrinology was consulted, methimazole was started for thyrotoxicosis. Formal TTE showed LVEF 20-25% with global reduction in left ventricular contractility, dilated left atrium and mild MR. He was given furosemide for pulmonary edema. TSI and TRAB were positive indicating Grave’s disease. He was successfully transferred out of the ICU. Patient gradually became euvolemic with significant improvement in energy, appetite and functional capacity. He was able to participate in physical therapy and was eventually discharged to rehab. Conclusion: This case addresses an uncommon but potentially life-threatening cause of undifferentiated shock. Physical exam, history and high degree of suspicion are key in early identification and treatment. Although thyroid cardiomyopathy is rare, Grave’s disease is common and ruling our thyrotoxicosis should be included in preliminary work up of undifferentiated shock. Presentation: Friday, June 16, 2023

Six-lead electrocardiography compared to single-lead electrocardiography and photoplethysmography of a wrist-worn device for atrial fibrillation detection controlled by premature atrial or ventricular contractions: six is smarter than one.

Smartwatches are commonly capable to record a lead-I-like electrocardiogram (ECG) and perform a photoplethysmography (PPG)-based atrial fibrillation (AF) detection. Wearable technologies repeatedly face the challenge of frequent premature beats, particularly in target populations for screening of AF. To investigate the potential diagnostic benefit of six-lead ECG compared to single-lead ECG and PPG-based algorithm for AF detection of the wrist-worn device. From the database of DoubleCheck-AF 249 adults were enrolled in AF group (n = 121) or control group of SR with frequent premature ventricular (PVCs) or atrial (PACs) contractions (n = 128). Cardiac rhythm was monitored using a wrist-worn device capable of recording continuous PPG and simultaneous intermittent six-lead standard-limb-like ECG. To display a single-lead ECG, the six-lead ECGs were trimmed to lead-I-like ECGs. Two diagnosis-blinded cardiologists evaluated reference, six-lead and single-lead ECGs as "AF", "SR", or "Cannot be concluded". AF detection based on six-lead ECG, single-lead ECG, and PPG yielded a sensitivity of 99.2%, 95.7%, and 94.2%, respectively. The higher number of premature beats per minute was associated with false positive outcomes of single-lead ECG (18.80 vs. 5.40 beats/min, P < 0.01), six-lead ECG (64.3 vs. 5.8 beats/min, P = 0.018), and PPG-based detector (13.20 vs. 5.60 beats/min, P = 0.05). Single-lead ECG required 3.4 times fewer extrasystoles than six-lead ECG to result in a false positive outcome. In a control subgroup of PACs, the specificity of six-lead ECG, single-lead ECG, and PPG dropped to 95%, 83.8%, and 90%, respectively. The diagnostic value of single-lead ECG (AUC 0.898) was inferior to six-lead ECG (AUC 0.971) and PPG-based detector (AUC 0.921). In a control subgroup of PVCs, the specificity of six-lead ECG, single-lead ECG, and PPG was 100%, 96.4%, and 96.6%, respectively. The diagnostic value of single-lead ECG (AUC 0.961) was inferior to six-lead ECG (AUC 0.996) and non-inferior to PPG-based detector (AUC 0.954). A six-lead wearable-recorded ECG demonstrated the superior diagnostic value of AF detection compared to a single-lead ECG and PPG-based AF detection. The risk of type I error due to the widespread use of smartwatch-enabled single-lead ECGs in populations with frequent premature beats is significant.

The association between frequent premature atrial contractions and recurrent stroke in a population of ischemic stroke

Objective: Premature atrial contractions (PACs) are a prevalent cardiac occurrence. Recent research indicates that PACs are linked to atrial fibrillation (AF), ischemic stroke, and mortality. We aimed to investigate the association of PACs and the risk of recurrent stroke in patients with ischemic stroke in sinus rhythm. Methods: The study was conducted as a cross-sectional study. 24-hour standard three-lead Holter ECG monitoring was performed for seven days and analyzed. Patients were separated into two groups based on the results of Holter ECG monitoring: those with subclinical AF and those with frequent PACs. Frequent PACs were characterized as more than fourteen PACs per hour and &amp;gt;3 PAC runs each 24 hours. Subclinical AF was defined as atrial fibrillation, atrial flutter, or atrial tachycardia events detected by implantable or wearable cardiac devices in people without AF symptoms and in whom clinical AF was not previously detected. Results: 150 patients, consisting of 82 men (54.7% of the total) and 68 women (45.3%), with an average age of 60.9±13.5 years, were enrolled in the research. Based on the Holter findings, patients were separated into subclinical AF (n=54) and frequent PACs (n=96).During hospitalization, recurrent ischemic stroke was detected in 6 patients (11%) in the subclinical AF arm and 26 patients (26%) in the frequent PACs arm (p=0.03). Six patients died of whom 4 died after a recurrent stroke event in the hospital. In univariate analysis age [OR: 1.03, 95%CI (1-1.07), p=0.02], dyslipidemia [OR: 2.68, 95%CI (1.16-6.18), p=0.021] and frequent PACs [OR: 2.97, 95%CI (1.13-7.76), p=0.026] were found significant predictors of recurrent stroke. Furthermore, in multivariate logistic regression analysis only frequent PACs [OR: 2.69, 95%CI (1-7.17), p=0.048] was found independent predictors of recurrent stroke. Conclusion: Frequent PACs on Holter analysis were significantly associated with recurrent ischemic stroke.

Left Atrial Function and Arrhythmias in Relation to Small Vessel Disease on Brain MRI: The Multi-Ethnic Study of Atherosclerosis.

Background Atrial fibrillation (AF) is associated with increased stroke risk and accelerated cognitive decline, but the association of early manifestations of left atrial (LA) impairment with subclinical changes in brain structure is unclear. We investigated whether abnormal LA structure and function, greater supraventricular ectopy, and intermittent AF are associated with small vessel disease on magnetic resonance imaging of the brain. Methods and Results In the Multi-Ethnic Study of Atherosclerosis, 967 participants completed 14-day ambulatory electrocardiographic monitoring, speckle tracking echocardiography and, a median 17 months later, magnetic resonance imaging of the brain. We assessed associations of LA volume index and reservoir strain, supraventricular ectopy, and prevalent AF with brain magnetic resonance imaging measures of small vessel disease and atrophy. The mean age of participants was 72 years; 53% were women. In multivariable models, LA enlargement was associated with lower white matter fractional anisotropy and greater prevalence of microbleeds; reduced LA strain, indicating worse LA function, was associated with more microbleeds. More premature atrial contractions were associated with lower total gray matter volume. Compared with no AF, intermittent AF (prevalent AF with <100% AF during electrocardiographic monitoring) was associated with lower white matter fractional anisotropy (-0.25 SDs [95% CI, -0.44 to -0.07]) and greater prevalence of microbleeds (prevalence ratio: 1.42 [95% CI, 1.12-1.79]). Conclusions In individuals without a history of stroke or transient ischemic attack, alterations of LA structure and function, including enlargement, reduced strain, frequent premature atrial contractions, and intermittent AF, were associated with increased markers of small vessel disease. Detailed assessment of LA structure and function and extended ECG monitoring may enable early identification of individuals at greater risk of small vessel disease.

Monitoring for atrial fibrillation prior to patent foramen ovale closure after cryptogenic stroke.

Patients who had a cryptogenic stroke (CS) suspected to be causally related to a patent foramen ovale (PFO) are candidates for percutaneous PFO closure. In such patients, it is important to screen for atrial fibrillation (AF). Limited guidance is available regarding AF monitoring strategies in CS patients with PFO addressing optimal monitoring technology and duration. To provide a narrative review of cardiac rhythm monitoring in CS patients considered for PFO closure, including current practices, stroke recurrences after CS, findings from monitoring studies in CS patients, and predictors for AF detection published in the literature. To propose a personalized strategy for cardiac monitoring in CS patients, accounting for aspects predicting AF detection. AF detection in CS patients is predicted by age, left atrial enlargement, prolonged PR interval, frequent premature atrial contractions, interatrial conduction block, diabetes, prior brain infarctions, leukoaraiosis, elevated B-type natriuretic peptide (BNP)/N-terminal pro B-type natriuretic peptide (NT-proBNP) levels, and a family history of AF, as well as composed scores (e.g. CHA2DS2-VASc, atrial fibrillation in embolic stroke of undetermined source (AF-ESUS)). The causal role of the PFO may be accounted for by the risk of paradoxical embolism (RoPE) score and/or the PFO-Associated Stroke Causal Likelihood (PASCAL) classification. A personalized approach to AF detection in CS patients is proposed, accounting for the likelihood of AF detection and aimed at obtaining sufficient confidence regarding the absence of AF in patients considered for PFO closure. In addition, the impact of high-risk PFO features on the monitoring strategy is discussed.

Arrhythmia Burden and Heart Rate Response During Exercise in Anderson-Fabry Disease.

Patients with Anderson-Fabry disease (AFD) have an elevated incidence of resting arrhythmias and ischemic heart disease, but their exercise arrhythmia burden and ischemic changes are not well understood. In addition, little research has been done on heart rate recovery in these patients. We retrospectively reviewed charts of patients with AFD who underwent maximal effort cardiopulmonary exercise testing (CPET) (n=44; 38.2 ± 13.8 yr; 23 men) from 2012 through 2018. Electrocardiographic, Holter monitoring, echocardiographic, cardiac magnetic resonance imaging, and patient demographic data were collected. No patient had adverse events that necessitated CPET termination, whereas 25 (57%) had ectopy during CPET, including 3 (7%) with frequent premature atrial contractions and 5 (11%) with frequent premature ventricular contractions. The ectopic burden was higher during resting electrocardiographic monitoring before exercise. In addition, 7 patients (16%) had pathologic ST-segment or T-wave changes on CPET, defined as ST-segment changes ≥2 mm. Among the patients who had concurrent cardiac magnetic resonance findings with their CPET (n=27), ST-segment or T-wave changes were associated with left ventricular myocardial mass (r=0.43, P=0.02). Chronotropic incompetence was seen during CPET in 28 patients (64%); however, only 2 patients (4%) had abnormal heart rate recovery at 1 minute. This study shows that patients with AFD can safely undergo exercise testing but have a high incidence of exercise-induced arrhythmias and ischemic changes. Ischemic electrocardiographic changes during exercise testing are associated with myocardial mass. Despite the chronotropic incompetence associated with AFD, heart rate recovery appears to be generally preserved in these patients.

Head-to-head comparison of single-lead and six-lead electrocardiography of a wrist-worn device for atrial fibrillation detection

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Funded by the European Regional Development Fund under agreement with the Research Council of Lithuania. Background The increasing numbers of available mHealth tools for electrocardiography (ECG)-based atrial fibrillation (AF) detection promote long-term screening. A common feature of smartwatches is lead-I-like ECG. However, only limited data exists directly comparing the performance of single-lead and six-lead wearable-recorded ECGs. Purpose To compare the accuracy of single-lead and six-lead ECGs of the same wrist-worn device for AF detection. Methods We included patients with AF which represent the main group for testing the diagnostic ability of wearable. In addition, authors selected control groups of stable sinus rhythm (SR) and SR with frequent premature contractions. Cardiac rhythm was monitored using an investigational wrist-worn device which provides six-lead ECG, similar to standard limb leads. To display a single-lead wearable-recorded ECGs, the same six-lead ECG tracings were trimmed to a width of lead-I-like ECGs. A validated Holter ECG device constituted a gold standard test for rhythm verification. Two independent diagnosis-blinded cardiologists evaluated reference, six-lead and single-lead ECGs as "AF", "SR", or "Inconclusive". A third cardiologist evaluated ECGs only in cases of physician disagreement. Results A total of 344 adult patients were enrolled in this study including AF group (121 patients) and control group of SR with or without frequent premature contractions (223 patients). Patients with missing (11/420; 2.62%) or insufficient quality (43/420; 10.24%) of wearable-recorded ECGs were excluded. AF detection based on single-lead and six-lead ECGs yielded sensitivity of 95.73% (95% CI 90.31–98.6%) and 99.16% (95% CI 95.41–99.98%), respectively. Specificity was 100% (95% CI 96.19–100%) for both single-lead and six-lead ECGs when differentiating between AF and stable SR. If patients with frequent premature beats were included in the control group, the specificity of single-lead and six-lead ECGs dropped to 95.81% (95% CI 92.31–98.07%) and 99.1% (95% CI 96.78–99.89%), respectively. False positive cases were more common for single-lead ECG (9/332) compared to six-lead ECG (2/341) (P=0.02). There was a strong association between reference ECGs and wearable-recorded ECGs (P&amp;lt;0.001): Cramer‘s V 0.91, (95% CI 0.82–1.0) for single-lead ECG and 0.98 (95% CI 0.89–1.0) for six-lead ECG. After including a control group of frequent premature contractions, single-lead ECG (12/344) was more frequently labelled "Inconclusive" than six-lead ECG (3/344) (P=0.01). Inter-rater agreement, measured as Cohen’s kappa, indicated great concordance in both methods but was higher for six-lead ECG (0.945, P&amp;lt;0.001) than single-lead ECG (0.887, P&amp;lt;0.001). Conclusions Six-lead ECG of a wearable device demonstrated higher diagnostic accuracy of AF detection than single-lead ECG when controlled by patients with frequent premature contractions. The performance of both methods was equivalent when controlled by patients with stable SR.

Mapping and Ablation of Isolated Frequent Symptomatic Premature Atrial Contractions in Patients With Structurally Normal Heart.

BackgroundThe present study investigated the safety and efficacy of mapping and ablating isolated premature atrial contractions (PACs) in patients with a structurally normal heart, as well as whether the elimination of PACs by radiofrequency catheter ablation (RFCA) improved symptoms and the quality of life.MethodsForty-three consecutive patients with frequent, symptomatic, and drug-refractory PACs, but without atrial tachyarrhythmias (≥5 beats), were enrolled. In all patients, we performed physical, laboratory, and imaging examinations to exclude structural heart disease. The quality of life questionnaire SF-36 before and 3 months after RFCA was performed in each patient.ResultsTwenty-three men and 20 women with an average age of 52.6 ± 17.6 years were finally enrolled. The mean number of PACs was 21,685 ± 9,596 per 24 h, and the mean PACs' burden was 28.9 ± 13.7%. Short runs of tachycardia (<5 atrial beats) were observed in 32 patients (74.4%). All patients underwent successful RFCA without complications. The activation time at the successful ablation sites preceded the onset of the P-wave by 36 ± 7.6 ms. During 15 ± 8 months of follow-up, the recurrence of PACs was observed in 2 patients. The 24-h PAC burden was significantly reduced 3 months after RFCA (mean 0.5%, p < 0.05). The quality of life scores were significantly increased 3 months after RFCA (all p < 0.05).ConclusionsRFCA was feasible, safe, and effective to eliminate isolated frequent, symptomatic, and drug-refractory PACs in patients with a structurally normal heart. The elimination of PACs by RFCA significantly improved symptoms and the quality of life.

Frequent premature atrial contractions as a signalling marker of atrial cardiomyopathy, incident atrial fibrillation, and stroke.

Premature atrial contractions are a common cardiac phenomenon. Although previously considered a benign electrocardiographic finding, they have now been associated with a higher risk of incident atrial fibrillation (AF) and other adverse outcomes such as stroke and all-cause mortality. Since premature atrial contractions can be associated with these adverse clinical outcomes independently of AF occurrence, different explanations have being proposed. The concept of atrial cardiomyopathy, where AF would be an epiphenomenon outside the causal pathway between premature atrial contractions and stroke has received traction recently. This concept suggests that structural, functional, and biochemical changes in the atria lead to arrhythmia occurrence and thromboembolic events. Some consensus about diagnosis and treatment of this condition have been published, but this is based on scarce evidence, highlighting the need for a clear definition of excessive premature atrial contractions and for prospective studies regarding antiarrhythmic therapies, anticoagulation or molecular targets in this group of patients.

High Specificity Wearable Device With Photoplethysmography and Six-Lead Electrocardiography for Atrial Fibrillation Detection Challenged by Frequent Premature Contractions: DoubleCheck-AF.

BackgroundConsumer smartwatches have gained attention as mobile health (mHealth) tools able to detect atrial fibrillation (AF) using photoplethysmography (PPG) or a short strip of electrocardiogram (ECG). PPG has limited accuracy due to the movement artifacts, whereas ECG cannot be used continuously, is usually displayed as a single-lead signal and is limited in asymptomatic cases.ObjectiveDoubleCheck-AF is a validation study of a wrist-worn device dedicated to providing both continuous PPG-based rhythm monitoring and instant 6-lead ECG with no wires. We evaluated its ability to differentiate between AF and sinus rhythm (SR) with particular emphasis on the challenge of frequent premature beats.Methods and ResultsWe performed a prospective, non-randomized study of 344 participants including 121 patients in AF. To challenge the specificity of the device two control groups were selected: 95 patients in stable SR and 128 patients in SR with frequent premature ventricular or atrial contractions (PVCs/PACs). All ECG tracings were labeled by two independent diagnosis-blinded cardiologists as “AF,” “SR” or “Cannot be concluded.” In case of disagreement, a third cardiologist was consulted. A simultaneously recorded ECG of Holter monitor served as a reference. It revealed a high burden of ectopy in the corresponding control group: 6.2 PVCs/PACs per minute, bigeminy/trigeminy episodes in 24.2% (31/128) and runs of ≥3 beats in 9.4% (12/128) of patients. AF detection with PPG-based algorithm, ECG of the wearable and combination of both yielded sensitivity and specificity of 94.2 and 96.9%; 99.2 and 99.1%; 94.2 and 99.6%, respectively. All seven false-positive PPG-based cases were from the frequent PVCs/PACs group compared to none from the stable SR group (P < 0.001). In the majority of these cases (6/7) cardiologists were able to correct the diagnosis to SR with the help of the ECG of the device (P = 0.012).ConclusionsThis is the first wearable combining PPG-based AF detection algorithm for screening of AF together with an instant 6-lead ECG with no wires for manual rhythm confirmation. The system maintained high specificity despite a remarkable amount of frequent single or multiple premature contractions.

Premature atrial contractions with multiple patterns of aberrant conduction followed by torsade de pointes in a patient with polymyalgia rheumatica

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)-1β, 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.

Factors Determining Occurrence of Arrhythmias in Patients Post-closure of Atrial Septal Defects.

ObjectivesThis study aimed to determine the risk factors for the occurrence of arrhythmias after either transcatheter or surgical closure of atrial septal defect.MethodsThis prospective study included 150 patients admitted for transcatheter or surgical closure of atrial septal defect. Transthoracic echocardiography together with a twelve-leads ECG were done during 1 and 3 months follow up. The paired T, chi-square and Logistic regression tests were used to detect any association between any arrhythmias and factors that may affect its occurrence.ResultsOne-hundred and twenty-three patients had percutaneous device closure while the remaining 27 patients had surgical closure. The youngest and oldest of the studied patients being 3 & 50 years old respectively with female (108) over male (42) predominance in incidence. After closure, 8 patients at one month and another 3 patients at three months follow up out of the total 150 patients had supraventricular arrhythmias in the form of frequent premature atrial contractions (6 patients), atrioventricular nodal re-entrant tachycardia (2 patients), and paroxysmal Atrial fibrillation (3 patients). No conduction abnormalities nor ventricular arrhythmias occurred. Multivariate analysis showed that age, P wave dispersion, systolic myocardial velocity of right ventricle, and systolic pulmonary artery pressure were independently associated with the occurrence of atrial arrhythmia after atrial septal defect repair.ConclusionAge, P wave dispersion, Systolic pulmonary artery pressure, and systolic myocardial velocity of the right ventricle are independent risk factors to develop arrythmias in patients after atrial septal defect closure.

A review of hand-held Electrocardiogram (ECG) recording devices

Funding AcknowledgementsType of funding sources: Public hospital(s). Main funding source(s): St Barts NHS TrustIntroductionThe advent of portable hand-held devices to record an electrocardiogram (ECG) in-clinic, has the potential to streamline patient assessment in many clinical environments. These ECG technologies are able to record one to six lead ECGs and enable rapid responses to clinical situations. These devices may also have a role in reducing interdepartmental movement of patients during the COVID-19 pandemic, by facilitating a one-stop shop for clinical evaluation. However despite their benefit, they can be more prone to artefact than a 12-lead ECG.PurposeTo describe the currently available hand-held ECG technologies, their ease of use and diagnostic accuracy for rhythm assessment.MethodAn online review was conducted to identify new ECG technologies. Clinical colleagues were also surveyed for recommendations with respect to specifications, availability of alternative products, and informed of the inclusion /exclusion criteria. The review included devices which had built-in abnormal rhythm notification or display, were cost-effective and easy to use. Devices were automatically excluded if cutaneous skin electrodes were required, no in-built ECG display or notification, additional data transfer required to access ECG data or a high unit cost.ResultsAn initial search uncovered nine devices, with five meeting inclusion /exclusion criteria. These devices were tabulated and compared predefined criteria (See table 1: ECG Technology comparisons). The analysis revealed that all devices utilised two finger placement on their recording electrodes to produce immediate ECG results – no cutaneous ECG application required. The KardiaMobile 6L™ had the largest number of beneficial features, namely multi-channel device, QTc interpretation, rapid diagnosis time and low cost. The intended use of hand-held devices is to detect AF. Four of five devices produced a snapshot ECG for rhythm identification on their display. However, AfibAlert™ devices provided an instant light alert if atrial fibrillation (AF) was detected. Instant check™, Dimitek™ and AfibAlert™ benefit from being complete stand-alone devices. In contrast, KardioMobile devices have a built-in ECG display for instant review however, they require a smart phone or tablet to store and transfer the data. These devices support a reliable internal AF algorithm to obtain a high negative predicted value to safely rule out AF. Frequent premature atrial contractions (PACs) are often difficult to distinguish from AF and can lead to high false-positive rate. Hand-held devices are prone to artefact, however accurate visual assessment able to significantly reduce the amount of ECGs deemed uninterpretable.ConclusionsHand-held ECG technology has potential to become a useful, cost-effective tool during patient consultations, with rapid identification of clinically important arrhythmias. However, limitations exist across providers. A pilot trial of these devices is planned to assess further. Figure.

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

ObjectiveTo evaluate the association of premature atrial contraction (PAC) frequency with cognitive test scores and prevalence of dementia or mild cognitive impairment (MCI). Materials and MethodsWe 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. ResultsDuring 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. ConclusionIn 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.