Diagnostic accuracy of a new detection algorithm for atrial fibrillation in cardiac telemonitoring with portable electrocardiogram devices.

BACKGROUND: Telemedical approaches targeting cardiac outpatients try to include electrocardiogram (ECG) analysis. Increasing numbers of monitored patients require automated preanalysis of the ECG to prioritize the evaluation for the clinical professional to enable an efficient intervention. METHODS: ECGs were recorded from 60 patients, both with a standard 12-lead ECG and with a new handheld ECG device having dry electrodes for direct skin contact. Recordings of the handheld device were automatically analyzed by a new algorithm. The 12-lead recordings were evaluated by a blinded cardiologist and then compared to the automated analysis of the handheld ECG. Sensitivity and specificity of the algorithm for the detection of atrial fibrillation (AF) were calculated. RESULTS: A total of 60 ECG strips having 122 ± 36 beats were registered. One hundred percent of the ECG strips were sufficient for automated heart rate count; 96.6%, for automated AF analysis; and 80%, for PQ, QRS, and QTc time measurements. AF detection had a sensitivity of 92.9% and a specificity of 90.9%. There was no difference in heart rate count between automated and manual analysis (median, 71 vs 70 beats per minute; P = .51). Automated measurements of a summary complex showed no difference for PQ time (165 vs 161 milliseconds, P = .50) but overestimated QRS (119 vs 90 milliseconds, P = .001) and QTc (489 vs 417 milliseconds, P < .001) times as compared to the 12-lead recordings analyzed manually. CONCLUSION: The new algorithm is suitable for automated preanalysis of the ECG data with regard to AF. It could be used for rapid selection of ECGs with relevant rhythm abnormalities from a large pool. Electrocardiographic data remain to be evaluated by health care professionals for exact diagnosis.

Electrocardiographic monitoring during marathon running: a proof of feasibility for a new telemedical approach.

OBJECTIVE: There is a risk for sudden cardiac death and nonfatal arrhythmias for marathon runners. A new telemedical approach to prevent sudden cardiac death could be online electrocardiogram monitoring during endurance sport events, which would allow the emergency services located along the running track to initiate instantaneous therapy. In a first proof-of-concept study we evaluate the feasibility of recording, transferring and analysing an electrocardiogram via a mobile phone (electrocardiogram streaming) and compare the quality to a conventional Holter electrocardiogram during marathon running. METHODS: A total of 10 recreational endurance runners are equipped with a Holter Tele-electrocardiogram and a standard smartphone connected via Bluetooth to each other in order to continuously record an electrocardiogram during a first marathon event (five runners) and a second marathon event (five runners). All streaming electrocardiogram data were transferred from the device to our telemedicine centre (Charité Campus Mitte, Berlin, Germany); the data were monitored live and stored for a subsequent offline analysis. The primary endpoint was the percentage of successful transfer time of the streaming electrocardiogram compared with Holter electrocardiogram; the secondary endpoint was the percentage of correctly identified arrhythmias in the observed period. RESULTS: It is technically feasible to stream an electrocardiogram during marathon running in the presence of thousands of mobile phone users. In addition, the identification of arrhythmias during a marathon is possible by electrocardiogram streaming. However, during the first race, the data transfer quality was low. After improvement of the software, in the subsequent race there was an extremely good quality in the data transfer via the mobile phone network (89%) and 100% of the rhythm disturbances could be detected in the streamed electrocardiogram. CONCLUSION: Online electrocardiogram surveillance during marathon running is a promising preventive concept. Intensive further technical development is needed first before further studies with clinical endpoints can start.

A new telemonitoring system intended for chronic heart failure patients using mobile telephone technology--feasibility study.

BACKGROUND: Remote monitoring is one modality of structured care in chronic heart failure. The purpose of this study was to evaluate the feasibility of a new wireless telemonitoring system via a mobile phone network. METHODS: Portable home devices for electrocardiogram, blood pressure, body weight and self-assessment measurements were connected (via Bluetooth) to a personal digital assistant (PDA) that performs automated encrypted transmission via mobile phone. Two telemedical centres were set-up. RESULTS: 30 healthy volunteers were enrolled and followed for 26 days. A total of 4002 single measurements were taken, 133 ± 37 per person. No data was lost or incorrectly allocated. 880 of 937 (94%) of the ECG recordings had sufficient diagnostic quality for rhythm analysis and single beat measurements. 50 continuous ECG-streams (312 min) without disruption were performed. Total system availability was 96.6%, including that of the mobile phone network. CONCLUSIONS: Mobile phone technology is suitable for continuous and secure medical data transmission. To evaluate the clinical use in chronic heart failure patients, a large multicentre randomized controlled trial (ClinicalTrials.gov Identifier: NCT00543881) was started.