REACT DX registry: Real world REACTion to atrial high rate episodes detected in implantable cardioverter-defibrillator recipients with a DX lead.

BACKGROUND: Atrial fibrillation (AF) is associated with significant morbidity and is predicted by atrial high rate events. The early detection of AF is paramount to timely interventions to reduce the morbidity of AF. The DX ICD system combined with Home Monitoring® allows for continuous atrial rhythm monitoring without the need for a dedicated atrial lead. OBJECTIVE: To establish the reaction to and timing of reactions to the detection of atrial high rate episodes (AHRE). METHODS: A prospective cohort of DX ICD systems was followed up and the response to AHREs was collected and evaluated. RESULTS: A total of 234 patients were enrolled; an AHRE ⩾ 6 min was detected in 13.7% of patients (n= 32) within a mean follow-up duration of 16 months. A high rate of oral anticoagulation (OAC) prescription was seen with the detection of AHREs in patients with a not-low risk CHA2DS2-VASc score. There was a delay in this prescription highlighting the potential to improve the timeliness of patient care in this group of patients. CONCLUSIONS: The DX ICD system provides rapid and ongoing atrial rhythm monitoring such that physicians are rapidly aware of AHRE without the need for a dedicated atrial lead, but local protocols are needed to improve the response time of anti-coagulation prescription.

Cardiac Autonomic Dysfunction and Incidence of de novo Atrial Fibrillation: Heart Rate Variability vs. Heart Rate Complexity.

BACKGROUND: The REACT DX registry evaluates standard therapies to episodes of long-lasting atrial tachyarrhythmias and assesses the quality of sensing and stability of the lead and the implantable cardioverter-defibrillator (ICD) (BIOTRONIK Lumax VR-T DX and successors) over at least a 1-year follow-up period. OBJECTIVE: To study the association between the risk of de novo device-detected atrial fibrillation (AF), the autonomic perturbations before the onset of paroxysmal AF and a 7-days heart rate variability (7dHRV) 1 month after ICD implantation. METHODS: The registry consists of 234 patients implanted with an ICD, including 10 with de novo long-lasting atrial tachyarrhythmias with no prior history of AF. The patients were matched via the propensity-score methodology as well as for properties directly influencing the ECGs recorded using GE CardioMem CM 3000. Heart rate variability (HRV) analysis was performed using standard parameters from time- and frequency-domains, and from non-linear dynamics. RESULTS: No linear HRV was associated with an increased risk of AF (p = n.s.). The only significant approach was derived from symbolic dynamics with the parameter "forbidden words" which distinguished both groups on all 7 days of measurements (p < 0.05), thereby quantifying the heart rate complexity (HRC) as drastically lower in the de novo AF group. CONCLUSION: Cardiac autonomic dysfunction denoted by low HRC may be associated with higher AF incidence. For patients with mild to moderate heart failure, standard HRV parameters are not appropriate to quantify cardiac autonomic perturbations before the onset of AF. Further studies are needed to determine the individual risk for AF that would enable interventions to restore autonomic balance in the general population.

Decreased external skeletal robustness in schoolchildren--a global trend? Ten year comparison of Russian and German data.

OBJECTIVES: Obesity and a reduced physical activity are global developments. Physical activity affects the external skeletal robustness which decreased in German children. It was assumed that the negative trend of decreased external skeletal robustness can be found in other countries. Therefore anthropometric data of Russian and German children from the years 2000 and 2010 were compared. METHODS: Russian (2000/2010 n = 1023/268) and German (2000/2010 n = 2103/1750) children aged 6-10 years were investigated. Height, BMI and external skeletal robustness (Frame-Index) were examined and compared for the years and the countries. Statistical analysis was performed by Mann-Whitney-Test. RESULTS: Comparison 2010 and 2000: In Russian children BMI was significantly higher; boys were significantly taller and exhibited a decreased Frame-Index (p = .002) in 2010. German boys showed significantly higher BMI in 2010. In both sexes Frame-Index (p = .001) was reduced in 2010. Comparison Russian and German children in 2000: BMI, height and Frame-Index were different between Russian and German children. German children were significantly taller but exhibited a lower Frame-Index (p<.001). Even German girls showed a significantly higher BMI. Comparison Russian and German children in 2010: BMI and Frame-Index were different. Russian children displayed a higher Frame-Index (p<.001) compared with Germans. CONCLUSIONS: In Russian children BMI has increased in recent years. Frame-Index is still higher in Russian children compared with Germans however in Russian boys Frame-Index is reduced. This trend and the physical activity should be observed in the future.

Decreased external skeletal robustness due to reduced physical activity?

OBJECTIVES: Childhood obesity is a global problem, e.g., due to physical inactivity. External skeletal robustness (Frame-Index) has decreased in German schoolchildren. An association between Frame-Index and physical activity was assumed. Further often body mass index (BMI) is analyzed without reference to bone structure. Therefore, we analyze relationships between Frame-Index, BMI, % body fat, and physical activity. METHODS: In a cross-sectional study, 691 German children aged 6-10 years were investigated. BMI, % body fat, Frame-Index, total steps p.w., sports club rate p.w., training time p.d., and TV-time p.d. were determined. RESULTS: Total steps (P < 0.001), BMI (P < 0.001), and % body fat (P = 0.024) are positively linked to Frame-Index. Total steps (P < 0.001), sports club rate (P = 0.001), and training time (P < 0.001) are negatively associated with % body fat. Total steps (P = 0.017) are negatively linked to BMI. TV-time is positively related to BMI (P < 0.001) and % body fat (P < 0.001). % Body fat is affected by age (P < 0.001), sex (P = 0.028), and total steps (P = 0.002). BMI is influenced by age (P < 0.001), and Frame-Index by sex (P < 0.001) and total steps (P = 0.029). Principal component analysis indicates an association between BMI and TV-time and Frame-Index and total steps. CONCLUSIONS: We demonstrate an association between external skeletal robustness and physical activity, which is not captured by in BMI measurements. Children should be physically active in order to maintain skeletal robustness.