EVALUATION OF THE RELIABILITY OF ST SEGMENT MONITORING BY TRANSTELEPHONIC ELECTROCARDIOGRAM TRANSMISSION

Introduction: Transtelephonic electrocardiographic transmission is a d iagnostic technique which has been systematically applied in recent ye ars, mainly for the detection of arrhythmias or pacemaker malfunction. The purpose of this study was to assess the efficacy of this method i n the recording and transmission of ST segment and T wave changes. Met hod: A Bruce protocol exercise stress test was carried out in 47 conse cutive patients (39 males, eight females, age 53.1 +/- 11.5 years) wit h suspected coronary artery disease (CAD). At the same time, a transte lephonic ECG system, with a 2-min memory and the capability for 16.5 d ays continuous recording, was used to transmit the ECG (modified leads II and V-5). Results: A positive ST segment shift was observed in 19 patients (40.4%) during the exercise test. The transtelephonic system recorded this change in 18 of these patients but missed the anterosept al ST segment depression (V-2-V-4) in one patient (sensitivity 94.7%). All of the 23 patients with no ST segment changes during the exercise test had a negative transtelephonic ECG transmission (specificity 100 %). The width of the ST depression recorded from modified lead II on t he transtelephonic recording was not significantly different from that of the 12-lead ECG. The same was true for modified lead V-5. Conclusi on: Transtelephonic ECG transmission in patients with suspected CAD ca n significantly contribute to the investigation of this problem, since the method has high sensitivity and specificity. The capacity for con tinuous recording and the memory of the device make possible the monit oring of high risk patients for a good length of time.