[Feasibility and reliability of a transtelephonic 12 leads ECG]

Feasibility and reliability of a 12 lead electrocardiogram (ECG), recorded by the patient himself and transmitted via telephone are mandatory for prehospital diagnosis of myocardial ischemia in patients with coronary heart disease. In this study, a 12-lead ECG recorded by patients and transmitted to the cardiology call center via telephone (Tele-ECG; model CG-7100; Card Guard) was compared with the conventional 12-lead ECG from the same patient recorded at the same time in 128 cases. The Tele-ECGs received by the call center were compared with conventional ECG by two cardiologists and one internist independently and blindly. In relation to the conventional ECG, reproducibility of PQ, QRS and QT-durations [ms] as measured in the Tele-ECG was 85%. Concordance between Tele-ECG and conventional ECG in the detection of negative T-waves was very high (Kappa value (kappa) 0.94, 0.96 and 0.97), respectively, depending on the physician. ST-segment changes were diagnosed correctly in most of the cases in Tele-ECG (kappa=0.98-0.99), as compared with the conventional ECG by all physicians. Concordance between Tele- and conventional ECG concerning the pattern of old myocardial infarction was very high (kappa=0.99) for all infarct localization. The limitations of Tele-ECG were of technical nature. In 14 cases, the peripheral electrodes were displaced; in 12 cases, there were baseline artifacts. These technical errors could be corrected in 126/128 patients (98.4%) by transtelephonic verbal communication. In conclusion, the reliability and feasibility of the 12-lead Tele-ECG-recorder used in this pilot study could be demonstrated. In an ongoing randomized controlled multicenter study, it is being investigated whether the strategy of prehospital diagnosis of acute coronary syndromes by Tele-ECG in combination with verbal communication is able to reduce pre- and in-hospital time delay, to avoid unnecessary hospital admissions and to reduce the economic burden of coronary heart disease.