Incidental Arrhythmias During Atrial Fibrillation Screening With Repeat 7-Day Holter ECGs in a Hospital-Based Patient Population

BACKGROUND

Screening for atrial fibrillation (AF) may reveal incidental arrhythmias of relevance. The aim of this study was to describe incidental arrhythmias detected during screening for AF in the STAR-FIB (Predicting SilenT AtRial FIBrillation in Patients at High Thrombembolic Risk) cohort study.

METHODS AND RESULTS

In the STAR-FIB cohort study, we screened hospitalized patients for AF with 3 repeat 7-day Holter ECGs. We analyzed all Holter ECGs for the presence of the following incidental arrhythmias: (1) sinus node dysfunction, defined as sinus pause of ≥3 seconds' duration; (2) second-degree (including Wenckebach) or higher-degree atrioventricular block (AVB); (3) sustained supraventricular tachycardia of ≥30 seconds' duration; and (4) sustained ventricular tachycardia of ≥30 seconds' duration. We furthermore report treatment decisions because of incidental arrhythmias. A total of 2077 Holter ECGs were performed in 794 patients (mean age, 74.7 years; 49% women), resulting in a mean cumulative duration of analyzable ECG signal of 414±136 hours/patient. We found incidental arrhythmias in 94 patients (11.8%). Among these were sinus node dysfunction in 14 patients (1.8%), AVB in 41 (5.2%), supraventricular tachycardia in 42 (5.3%), and ventricular tachycardia in 2 (0.3%). Second-degree AVB was found in 23 patients (2.9%), 2:1 AVB in 10 (1.3%), and complete AVB in 8 (1%). Subsequently, 8 patients underwent pacemaker implantation, 1 for sinus node dysfunction (post-AF conversion pause of 9 seconds) and 7 for advanced AVB. One patient had an implantable cardioverter-defibrillator implanted for syncopal ventricular tachycardia.

CONCLUSIONS

Incidental arrhythmias were frequently detected during screening for AF in the STAR-FIB study and resulted in device therapy in 1.1% of our cohort patients.

Prognostic value of right ventricular dyssynchrony in adults with repaired tetralogy of Fallot

OBJECTIVE

Residual sequelae after surgical repair of tetralogy of Fallot (rTOF) affect clinical outcome. We investigated the prognostic impact of right ventricular (RV) dyssynchrony in adults with rTOF years after the surgical repair.

METHODS

Patients from the Swiss Adult Congenital HEart disease Registry were included. NT-proBNP levels, echocardiography, exercise testing and MRI data were collected. An offline strain analysis to quantify RV-ventricular and interventricular dyssynchrony was performed. The standard deviation of the time-to-peak shortening (TTP) of six RV segments defined the RV Dyssynchrony Index (RVDI). Maximal difference of TTP between RV and left ventricular segments defined the interventricular shortening delay (IVSD). Predictors of a composite adverse event (arrhythmias, hospitalisation for heart failure and death) were identified by multivariate Cox regression analysis. Their median values were used to create a risk score.

RESULTS

Out of 285 included patients (mean age 34±14 years), 33 patients (12%) experienced an adverse event during a mean follow-up of 48±21 months. No correlation was found between RVDI, IVSD and clinical events. NT-proBNP, right atrial area and peak heart rate were independent predictors of outcomes. After 4 years-follow-up, no adverse events occurred in patients at low risk (score=0 points), while an adverse event occurred in 62% of patients at high risk (score=3 points, p<0.001).

CONCLUSION

In our cohort of adults with rTOF, surrogates of RV dyssynchrony did not correlate with outcomes. A multimodality approach was effective in predicting the risk for adverse events.

Impact of left atrial size and strain on new atrial arrhythmias during a 5-year follow-up in adults with congenital heart disease

Introduction

Atrial arrhythmias are a common and important cause of morbidity and mortality in adults with congenital heart disease (ACHD). In acquired heart disease, left atrial (LA) strain has been shown to predict supraventricular tachyarrhythmias (SVT). This study sought to investigate if LA strain is also a reliable predictor of SVT in the ACHD population.

Method

We retrospectively obtained baseline clinical and echocardiographic data, including LA function parameters and strain, in 206 ACHD patients. Only patients with sinus rhythm at baseline and 5-years follow-up were included (median age 29, IQR 22–41 years). 157 participants had a left heart defect (aortic stenosis or aortic coarctation, with or without correction) and 49 a right heart defect (Fallot physiology). Diagnosis of sustained SVT was determined from clinical reports during the follow-up period (standard 12-lead ECG, ECG Holter).

Results

During a median follow-up of 6.2 years, a new or recurrent sustained SVT occurred in 16 patients (7.8%). Patients baseline characteristics are depicted in Table 1. Patients who developed SVT were older, had larger LA dimensions and left ventricular mass, more likely diastolic dysfunction on echo, and a lower peak LA longitudinal strain (PALS). PALS was a good predictor of SVT risk in patients with left and right heart defects with an area under the receiver-operating-curve of 0.857. By Cox regression analysis, patient in the lowest quartile for PALS had a 16.7-fold higher hazard ratio of SVT (95% confidence interval, 4.7 to 59.0, p&lt;0.001) in comparison with the top three quartiles. Overall freedom from arrhythmia after 1, 3 and 5 years of follow-up was 98.1%, 96.1% and 94.2%, respectively. The freedom from SVT as a function of PALS quartiles is shown in Figure 1.

Conclusion

PALS provides predictive information about the occurrence of SVT in the ACHD population, regardless of the type of the lesion. Including the measurement of LA strain in the follow-up of these patients may permit to better identify patients at risk of future atrial arrhythmias.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Universitätsklinik für Kardiologie, Inselspital Bern

Gender gap in study inclusion: Insights from the STAR-FIB cohort study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Swiss National Science Foundation Swiss Heart Foundation

Background

The underrepresentation of women in cardiovascular clinical trials is well described but cannot be fully explained by sex-specific differences in the prevalence of cardiovascular diseases. Data on potential sex- and gender-related differences in study exclusion reasons are scarce.

The STAR-FIB cohort study aimed to estimate the age and sex-specific prevalence of screening-detected atrial fibrillation (AF) in 800 hospitalized patients aged 65-84 years using serial seven-day ECGs. Recruitment for study inclusion was stratified by sex (female/male, as stated in the patient’s records) and age (four age bands, ≥65 to &lt;70, ≥70 to &lt;75, ≥75 to &lt;80, and ≥80 to &lt;85 years), and was truncated for each subgroup after the inclusion of 100 participants.

Purpose

To assess sex and gender differences in patient recruitment for inclusion in the STAR-FIB cohort study.

Methods

A screening log containing sex-category, age, and reasons for exclusion was maintained. Exclusion criteria are shown in the figure. For the purpose of the present study, an explorative analysis of all exclusion criteria with respect to sex category was done.

Results

Overall, 11’470 patients were identified for eligibility, 795 patients (49% women; mean age 75 years) were enrolled, and 10’675 patients (52% women vs. 48% men, p =0.13) were not enrolled. The two major exclusion reasons were unwillingness to participate, which was more frequent in women (27.9% of women vs. 18.4% of men, p &lt; 0.01), and the presence of clinical AF, which was more prevalent in men (27.1% of men vs. 20.5 % of women, p &lt; 0.01). A detailed analysis of all exclusion criteria analysed by sex category is provided in the figure.

Conclusions

Clinical AF was more frequent in men, in accordance with the well described sex-driven (biological) higher prevalence of AF in men. In contrast, we found a higher percentage of women unwilling to participate in this study, which may represent a more gender-based (sociocultural) phenomenon. A further exploration of these findings should be performed and may help to identify and potentially overcome modifiable obstacles for study participation.

Incidental arrhythmias during atrial fibrillation screening in a hospital-based patient population

Funding Acknowledgements

Type of funding sources: None.

Introduction

Screening for atrial fibrillation may reveal other, incidental arrhythmias of relevance. We sought to describe such incidental arrhythmias in the prospective STARFIB cohort study, which screened for silent atrial fibrillation in hospitalized patients aged 65-84 years.

Method

Patients included in the STARFIB cohort study had up to three 7-day Holter ECGs, performed in two-month intervals. We analysed all the 7-day Holter ECGs of study participants for the presence of one of the following incidental arrhythmias: 1) sick-sinus-syndrome (SSS), defined as sinus arrest of ≥3 seconds duration; 2) second or higher degree atrioventricular block (AVB); 3) sustained atrial tachycardia of ≥30 seconds duration (AT); and 4) sustained ventricular tachycardia of ≥30 seconds duration (VT).

Results

A total of 2’077 Holter ECGs were performed in 794 patients (mean age 74.7 years; 49% females), resulting in a mean cumulative duration of an analyzable ECG signal of 414±136 hours per patient. We found incidental arrhythmias in 94 patients (11.8%). Among these were SSS in 14 patients (1.8%), AVB in 41 (5.2%), AT in 41 (5.2%), and VT in two (0.3%). The median pause duration in SSS was 4 seconds and SSS resulted in pacemaker implantation in one patient with a pause of 9 seconds duration. The most severe type of AVB found per patient was second degree AVB type Wenkebach in 23 patients (2.9%), second degree AVB type Mobitz or 2:1 AV conduction in 10 patients (1.3%) and complete AVB in 8 (1%; maximum pause 18 seconds). AVB led to pacemaker implantation in 9 patients (1.1%). The median duration and heart rate of AT was 2.2 minutes and 144 bpm, respectively. Initiation of betablocker therapy was recommended in 3 patients (0.4%) due to symptomatic AT. The duration and heart rate of VT was 3 minutes at 216 bpm in one patient and 38 seconds at 150 bpm in another. The former patient with VT experienced syncope and an ICD was implanted, whereas in the latter the betablocker dose was increased. One patient died from a non-cardiac cause during a Holter ECG, which showed progressive bradycardia and finally asystole.

Conclusion

Incidental arrhythmias were frequently discovered during screening for atrial fibrillation and resulted in device therapy in 1.4% of our cohort patients.

Assessment of New Onset Arrhythmias After Transcatheter Aortic Valve Implantation Using an Implantable Cardiac Monitor

Background

Transcatheter aortic valve implantation (TAVI) is associated with new onset brady- and tachyarrhythmias which may impact clinical outcome.

Aims

To investigate the true incidence of new onset arrhythmias within 12 months after TAVI using an implantable cardiac monitor (ICM).

Methods

One hundred patients undergoing TAVI received an ICM within 3 months before or up to 5 days after TAVI. Patients were followed-up for 12 months after discharge from TAVI for the occurrence of atrial fibrillation (AF), bradycardia (≤30 bpm), advanced atrioventricular (AV) block, sustained ventricular and supraventricular tachycardia.

Results

A previously undiagnosed arrhythmia was observed in 31 patients (31%) and comprised AF in 19 patients (19%), advanced AV block in 3 patients (3%), and sustained supraventricular and ventricular tachycardia in 10 (10%) and 2 patients (2%), respectively. Three patients had a clinical diagnosis of sick-sinus-syndrome. A permanent pacemaker (PPM) was implanted in six patients (6%). The prevalence of pre-existing AF was 28%, and 47% of the patients had AF at the end of the study period. AF burden was significantly higher in patients with pre-existing [26.7% (IQR 0.3%; 100%)] compared to patients with new-onset AF [0.0% (IQR 0.0%; 0.06%); p = 0.001]. Three patients died after TAVI without evidence of an arrhythmic cause according to the available ICM recordings.

Conclusions

Rhythm monitoring for 12 months after TAVI revealed new arrhythmias, mainly AF, in almost one third of patients. Atrial fibrillation burden was higher in patients with prevalent compared to incident AF. Selected patients may benefit from short-term remote monitoring.

Trial Registration

https://clinicaltrials.gov/: NCT02559011.

Differences in Atrial Remodeling in Hypertrophic Cardiomyopathy Compared to Hypertensive Heart Disease and Athletes' Hearts

Background: Hypertrophic cardiomyopathy (HCM), hypertensive heart disease (HHD) and athletes’ heart share an increased prevalence of atrial fibrillation. Atrial cardiomyopathy in these patients may have different characteristics and help to distinguish these conditions. Methods: In this single-center study, we prospectively collected and analyzed electrocardiographic (12-lead ECG, signal-averaged ECG (SAECG), 24 h Holter ECG) and echocardiographic data in patients with HCM and HHD and in endurance athletes. Patients with atrial fibrillation were excluded. Results: We compared data of 27 patients with HCM (70% males, mean age 50 ± 14 years), 324 patients with HHD (52% males, mean age 75 ± 5.5 years), and 215 endurance athletes (72% males, mean age 42 ± 7.5 years). HCM patients had significantly longer filtered P-wave duration (153 ± 26 ms) and PR interval (191 ± 48 ms) compared to HHD patients (144 ± 16 ms, p = 0.012 and 178 ± 31, p = 0.034, respectively) and athletes (134 ± 14 ms, p = 0.001 and 165 ± 26 ms, both p < 0.001, respectively). HCM patients had a mean of 4.9 ± 16 premature atrial complexes per hour. Premature atrial complexes per hour were significantly more frequent in HHD patients (27 ± 86, p < 0.001), but not in athletes (2.7 ± 23, p = 0.639). Left atrial volume index (LAVI) was 43 ± 14 mL/m2 in HCM patients and significantly larger than age- and sex-corrected LAVI in HHD patients 30 ± 10 mL/m2; p < 0.001) and athletes (31 ± 9.5 mL/m2; p < 0.001). A borderline interventricular septum thickness ≥13 mm and ≤15 mm was found in 114 (35%) HHD patients, 12 (6%) athletes and 3 (11%) HCM patients. Conclusions: Structural and electrical atrial remodeling is more advanced in HCM patients compared to HHD patients and athletes.

The SilenT AtRial FIBrillation (STAR-FIB) study programme - design and rationale

AIMS OF THE STUDY

Anticoagulation of patients with screen-detected atrial fibrillation may prevent ischaemic strokes. The STAR-FIB study programme aims to determine the age- and sex-specific prevalence of silent atrial fibrillation and to develop a clinical prediction model to identify patients at risk of undiagnosed atrial fibrillation in a hospitalised patient population.

METHODS

The STAR-FIB study programme includes a prospective cohort study and a case-control study of hospitalised patients aged 65&ndash;84 years, evenly distributed for both age and sex. We recruited 795 patients without atrial fibrillation for the cohort study (49.2% females; median age 74.8 years). All patients had three serial 7-day Holter ECGs to screen for silent atrial fibrillation. The primary endpoint will be any episode of atrial fibrillation or atrial flutter of &ge;30 seconds duration. The age- and sex-specific prevalence of newly diagnosed atrial fibrillation will be estimated. For the case-control study, 120 patients with paroxysmal atrial fibrillation were recruited as cases (41.7% females; median age 74.6 years); controls will be randomly selected from the cohort study in a 2:1 ratio. All participants in the cohort study and all cases were prospectively evaluated including clinical, laboratory, echocardiographic and electrical parameters. A clinical prediction model for undiagnosed atrial fibrillation will be derived in the case-control study and externally validated in the cohort study.

CONCLUSIONS

The STAR-FIB study programme will estimate the age- and sex-specific prevalence of silent atrial fibrillation in a hospitalised patient population, and develop and validate a clinical prediction model to identify patients at risk of silent atrial fibrillation.

Comparison of lead failure manifestation of Biotronik Linox with St. Jude Medical Riata and Medtronic Sprint Fidelis lead

PURPOSE

To compare lead failure manifestation and lead performance of the Biotronik Linox/Sorin Vigila defibrillator lead (Linox group) with the St. Jude Medical Riata/Riata ST (Riata group) and Medtronic Sprint Fidelis defibrillator leads (Fidelis group).

METHODS

We assessed the performance of all aforementioned leads implanted at our center and investigated the manifestation of lead failures.

RESULTS

Of 93 Linox, 86 Riata, and 81 Fidelis leads implanted at our center, 11 (12%), 22 (26%), and 25 (31%) leads failed during a median follow-up of 46, 61, and 84 months, respectively. Inappropriate shocks were delivered in 64% (Linox), 5% (Riata), and 32% (Fidelis) of lead failures; a device alert was noted in none (Linox), 5% (Riata), and 52% (Fidelis); and lead failure was a coincidental finding in 36% (Linox), 91% (Riata), and 16% (Fidelis) of cases (p < 0.001). Non-physiological high rate signals were observed in 73% (Linox), 27% (Riata), and 80% (Fidelis) of lead failures (p = 0.001) and damaged lead integrity was found in 36% (Linox), 73% (Riata), and 24% (Fidelis) of cases (p = 0.064). Lead survival at 5 years was 88%, 92%, and 71% for Linox, Riata, and Fidelis group, respectively.

CONCLUSIONS

The most frequent clinical manifestation of lead failure was inappropriate shocks for Linox, coincidental finding for Riata and device alert for Fidelis leads. Non-physiological high rate signals were frequently observed in Linox and Fidelis lead failures whereas in Riata lead failures, a damaged lead integrity was the predominant finding.

The search for atrial fibrillation and its impact on public health

Atrial fibrillation may be clearly symptomatic and is easily amenable to state-of-the-art treatment, most importantly oral anticoagulation therapy for the prevention of thromboembolism. However, atrial fibrillation may also go unnoticed for long periods in many patients. This silent or subclinical atrial fibrillation is nevertheless associated with thromboembolic risk just like clinically evident atrial fibrillation. Early detection of atrial fibrillation in patients at increased thromboembolic risk and consequent oral anticoagulation therapy may have a significant impact on public health. This review focuses on screening recommendations for atrial fibrillation and on the impact of silent atrial fibrillation in various clinical scenarios.