A wearable remote monitoring system for the identification of subjects with a prolonged QT interval or at risk for drug-induced long QT syndrome.

BACKGROUND: A correct measurement of the QT interval in the out-of-hospital setting is important whenever the long QT syndrome (LQTS) is suspected or a therapy might lead to drug-induced LQTS (diLQTS) because QT interval monitoring in the initial days of therapy could alert to dangerous QT prolongation. We explored whether automated QTc measurements (BGM) by BodyGuardian™ (BG), a wearable remote monitoring system, are sufficiently reliable compared to our own manual measurements (MM) performed on the same beats during 12­lead Holter recordings in LQTS patients (pts) and in healthy controls. METHODS: We performed 351 measurements in 20 LQTS pts and 16 controls. MM and BGM were compared by a Bland-Altman plot (BAp). High values of BAp indicate large differences between measurements. RESULTS: In all 36 subjects QTc was 446 ±â€¯41 and 445 ±â€¯47 ms in MM and BGM, respectively. The mean ±â€¯SE BAp was -1.4 ±â€¯1.8 ms for QTc in all subjects, 8.3 ±â€¯2.3 and -7.2 ±â€¯2.5 ms respectively in controls and LQTS. The disagreement between BGM and MM <15 ms in all, in controls, and in LQTS was respectively 57%, 63% and 54%. Among controls, there were only 3/132 false positive measurements (BGM QTc >470 ms when MM QTc <440 ms) in 3 different subjects. Among LQTS, there were 10/219 false negative measurements (BGM QTc <440 ms when MM QTc >470 ms) in 6 pts, but only two had multiple false negative values. CONCLUSIONS: This wearable monitoring system reliably identifies a prolonged QT interval and probably also subjects at risk for diLQTS.

Comparative performance assessment of commercially available automatic external defibrillators: A simulation and real-life measurement study of hands-off time.

PURPOSE: Early and good quality cardiopulmonary resuscitation (CPR) and the use of automated external defibrillators (AEDs) improve cardiac arrest patients' survival. However, AED peri- and post-shock/analysis pauses may reduce CPR effectiveness. METHODS: The time performance of 12 different commercially available AEDs was tested in a manikin based scenario; then the AEDs recordings from the same tested models following the clinical use both in Pavia and Ticino were analyzed to evaluate the post-shock and post-analysis time. RESULTS: None of the AEDs was able to complete the analysis and to charge the capacitors in less than 10s and the mean post-shock pause was 6.7±2.4s. For non-shockable rhythms, the mean analysis time was 10.3±2s and the mean post-analysis time was 6.2±2.2s. We analyzed 154 AED records [104 by Emergency Medical Service (EMS) rescuers; 50 by lay rescuers]. EMS rescuers were faster in resuming CPR than lay rescuers [5.3s (95%CI 5-5.7) vs 8.6s (95%CI 7.3-10). CONCLUSIONS: AEDs showed different performances that may reduce CPR quality mostly for those rescuers following AED instructions. Both technological improvements and better lay rescuers training might be needed.

End-tidal carbon dioxide and defibrillation success in out-of-hospital cardiac arrest.

PURPOSE: Basing on the relationship between the quality of cardiopulmonary resuscitation (CPR) and the responsiveness of VF to the defibrillation we aimed to assess whether the values of ETCO2 in the minute before defibrillation could predict the effectiveness of the shock. MATERIALS AND METHODS: We retrospectively evaluated the reports generated by the manual monitor/defibrillator (Corpuls by GS Elektromedizinische Geräte G. Stemple GmbH, Germany) used for cases of VF cardiac arrest from January 2015 to December 2016. The mean ETCO2 value of the minute preceding the shock (METCO260) was computed. A blind evaluation of the effectiveness of each shock was provided by three cardiologists. RESULTS: A total amount of 207 shocks were delivered for 62 patients. When considering the three tertiles of METCO260 (T1:METCO260 ≤ 20mmHg; T2: 20mmHg < METCO260 ≤ 31mmHg and T3: METCO260 > 31mmHg) a statistically significant difference between the percentages of shock success was found (T1: 50%; T2: 63%; T3: 78%; Chi square p=0.003; p for trend <0.001). When the METCO260 was lower than 7mmHg no shock was effective and when the METCO260 was higher than 45mmHg no shock was ineffective. Shocks followed by ROSC were preceded by higher values of METCO260 as compared either to ineffective shocks or effective ones without ROSC. CONCLUSIONS: This is the first demonstration of the relation between ETCO2 and defibrillation effectiveness. Our findings stress the pivotal role of High Quality CPR, monitored via ETCO2, and suggest ETCO2 monitoring as an additional weapon to guide defibrillation.