The right ventricle best predicts the race performance in amateur ironman athletes

Purpose: The Ironman (IM) triathlon is a popular ultra endurance competition, consisting of a 3.8km swimming, 180.2km cycling, and a 42.2km run. The aim of this study was to investigate predictors of IM race time, comparing echocardiographic findings, anthropometric measures, and training characteristics.Methods: Amateur IM athletes (ATHL) participating in the Zurich IM race in 2010 were included. Participants were examined the day before the race by a comprehensive echocardiographic examination. Moreover, anthropometric measurements were obtained the same day. During the 3 months before the race, each IM-ATHL maintained a detailed training diary. Recorded data were related to total Ironman race time.Results: Thirty-eight Ironman finishers (average age 38±9 years, 32 male [84%]) were evaluated. Average total race time was 684±89 minutes. For right ventricular fractional area change (average: 45±7%, Spearman-ρ=-0.33; p=0.05) a weak correlation with race time was observed. Race performance exhibited stronger associations with percent body fat (15.2±5.6%, ρ=0.56; p=0.001), speed in running training (11.7±1.2 km/h, ρ=-0.52; p=0.002), and left ventricular myocardial mass index (98±24 g/m, ρ=-0.42; p=0.009). The strongest association was found between race time and right ventricular end-diastolic area (22±4 cm, ρ=-0.64; p<0.0001). In multivariate analysis, right ventricular end-diastolic area (beta=-16.7, 95% confidence interval: -27.3-[-6.1]; p=0.003) and percent body fat (beta=6.8, 95% confidence interval: 1.1-12.6; p=0.02) were independently predictive of Ironman race time.Conclusions: In amateur IM-ATHL, RV end-diastole area and percent body fat were independently related to race performance. RV end-diastolic area was the strongest predictor of race time. The role of the RV in endurance exercise may thus be more important than previously thought and needs to be further studied

High Incidence of Inappropriate Alarms in Patients with Wearable Cardioverter-Defibrillators: Findings from the Swiss WCD Registry.

BACKGROUND The wearable cardioverter defibrillator (WCD) uses surface electrodes to detect arrhythmia before initiating a treatment sequence. However, it is also prone to inappropriate detection due to artefacts. OBJECTIVE The aim of this study is to assess the alarm burden in patients and its impact on clinical outcomes. METHODS Patients from the nationwide Swiss WCD Registry were included. Clinical characteristics and data were obtained from the WCDs. Arrhythmia recordings ≥30 s in length were analysed and categorized as VT/VF, atrial fibrillation (AF), supraventricular tachycardia (SVT) or artefact. RESULTS A total of 10653 device alarms were documented in 324 of 456 patients (71.1%) over a mean WCD wear-time of 2.0 ± 1.6 months. Episode duration was 30 s or more in 2996 alarms (28.2%). One hundred and eleven (3.7%) were VT/VF episodes. The remaining recordings were inappropriate detections (2736 (91%) due to artefacts; 117 (3.7%) AF; 48 (1.6%) SVT). Two-hundred and seven patients (45%) had three or more alarms per month. Obesity was significantly associated with three or more alarms per month (p = 0.01, 27.7% vs. 15.9%). High alarm burden was not associated with a lower average daily wear time (20.8 h vs. 20.7 h, p = 0.785) or a decreased implantable cardioverter defibrillator implantation rate after stopping WCD use (48% vs. 47.3%, p = 0.156). CONCLUSIONS In patients using WCDs, alarms emitted by the device and impending inappropriate shocks were frequent and most commonly caused by artefacts. A high alarm burden was associated with obesity but did not lead to a decreased adherence

High Incidence of Inappropriate Alarms in Patients with Wearable Cardioverter-Defibrillators: Findings from the Swiss WCD Registry

BACKGROUND The wearable cardioverter defibrillator (WCD) uses surface electrodes to detect arrhythmia before initiating a treatment sequence. However, it is also prone to inappropriate detection due to artefacts. OBJECTIVE The aim of this study is to assess the alarm burden in patients and its impact on clinical outcomes. METHODS Patients from the nationwide Swiss WCD Registry were included. Clinical characteristics and data were obtained from the WCDs. Arrhythmia recordings ≥30 s in length were analysed and categorized as VT/VF, atrial fibrillation (AF), supraventricular tachycardia (SVT) or artefact. RESULTS A total of 10653 device alarms were documented in 324 of 456 patients (71.1%) over a mean WCD wear-time of 2.0 ± 1.6 months. Episode duration was 30 s or more in 2996 alarms (28.2%). One hundred and eleven (3.7%) were VT/VF episodes. The remaining recordings were inappropriate detections (2736 (91%) due to artefacts; 117 (3.7%) AF; 48 (1.6%) SVT). Two-hundred and seven patients (45%) had three or more alarms per month. Obesity was significantly associated with three or more alarms per month (p = 0.01, 27.7% vs. 15.9%). High alarm burden was not associated with a lower average daily wear time (20.8 h vs. 20.7 h, p = 0.785) or a decreased implantable cardioverter defibrillator implantation rate after stopping WCD use (48% vs. 47.3%, p = 0.156). CONCLUSIONS In patients using WCDs, alarms emitted by the device and impending inappropriate shocks were frequent and most commonly caused by artefacts. A high alarm burden was associated with obesity but did not lead to a decreased adherence