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.

Association of reduced peak left atrial strain with supraventricular arrhythmia in adults with congenital heart disease.

Atrial arrhythmias are an important cause of morbidity and mortality in adults with congenital heart disease (ACHD). In acquired heart disease, the left atrial (LA) strain has been shown to predict supraventricular tachyarrhythmias (SVT). This study aimed to investigate whether reduced LA strain is associated with SVT in ACHD patients. This retrospective, single-center cohort study collected baseline clinical and echocardiographic data of 206 ACHD patients (157 left heart defect, 49 right heart defect). Patients with sinus rhythm at baseline and a 5-year follow-up (median age 29, IQR 22-41 years) were included. Diagnosis of sustained SVT was determined from clinical reports during the follow-up period. New or recurrent sustained SVT occurred in 16 patients (7.8%, median follow-up of 6.2 years). Patients who developed SVT were older, more likely to have diastolic dysfunction, and had larger LA dimensions, left ventricular mass, and a lower peak LA longitudinal strain (PALS). Lower PALS was associated with higher risk of SVT in patients with left and right heart defects. Patients in the lowest quartile for PALS had a 15.9-fold higher hazard ratio of SVT (95% confidence interval, 4.5 to 56.0, p < 0.001) in comparison with the top three quartiles. PALS provides information about the occurrence of SVT in the ACHD population. Including measurement of LA strain in the follow-up of these patients may allow to better identify patients at risk of future atrial arrhythmias.

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.

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 65–84 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 ≥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.

Age and Sex Specific Prevalence of Clinical and Screen-Detected Atrial Fibrillation in Hospitalized Patients.

BACKGROUND: The prevalence of atrial fibrillation (AF) is high in older patients. The present study aimed to estimate the age and sex specific prevalence of clinical and screen-detected atrial fibrillation (AF) in hospitalized patients. METHODS: The STAR-FIB cohort study was a prospective cohort study recruiting participants from a large source population of hospitalized patients aged 65-84 years. The estimated size of the source population was 26,035 (95% CI 25,918-26,152), and 795 consenting patients without clinical AF were included in the cohort study after stratification by sex and age (49.2% females; mean age 74.7 years). Patients in the cohort study underwent three seven-day Holter ECGs in intervals of two months to screen for AF. RESULTS: In the source population, the estimated prevalence of clinical AF was 22.2% (95% CI 18.4-26.1), 23.8% for males (95% CI 20.9-26.6) and 19.8% for females (95% CI 17.3-22.4; p for difference between sexes, 0.004). There was a linear trend for an increase in the prevalence of clinical AF with increasing age, overall and in both sexes. In the cohort study, AF was newly diagnosed in 38 patients, for an estimated prevalence of screen-detected AF of 4.9% overall (95% CI 3.3-6.6), 5.5% in males (95% CI 3.2-7.8) and 4.0% in females (95% CI 2.0-6.0; p for difference between sexes, 0.041). The estimated prevalence of screen-detected AF in the source population was 3.8% overall, 4.2% in males and 3.2% in females. CONCLUSION: In a large hospital-based patient population aged 65-84 years, the prevalence of clinical AF and of screen-detected AF was 22.2% and 3.8%, respectively, and significantly higher in males than females.

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.