Continuous computer-assisted electrocardiographic monitoring in patients with acute myocardial infarction: early experience

Results of 3311 h of continuous digital 12-lead ST segment monitoring in a pilot population of 77 patients treated early in myocardial infarction (MI) with thrombolytic therapy are reported. `Mean beat´ signal processing over 353 min of monitoring in 12 patients subjected to normal flight vibration during helicopter transport was compared with 390 min of monitoring in 12 patients in the coronary care unit (CCU). Automated ST episode detection triggered 15 episodes in helicopter and 19 episodes in CCU, of which 3/15 (20%) and 7/19 (37%) were artifact, respectively. From the 77 patients overall, ST trend evidence of changes in infarct vessel patency was noted more than twice in 38 (49%), more than four times in 21 (27%), and more than six times in 11 (14%). ST evidence of patency change occurred from 30 s to 47.6 h apart. It is concluded that mean beat signal processing can provide technically adequate ECG monitoring information even with a vibrating signal source during helicopter transport and that continuous ST monitoring may be useful for detecting changes in infarct vessel patency occurring outside the brief time window of acute angiography