Improved detection of silent cardiac ischemia with a 12-lead portable microprocessor-driven real-time electrocardiographic monitor

Abstract

Objective: To compare a microprocessor-driven real-time 12-lead electrocardiographic monitoring device with Holter monitoring for detection of ischemia.

Design: Electrocardiographic monitoring was conducted in 110 patients at bed rest or undergoing surgical procedures.

Material and methods: In three groups of patients, simultaneous monitoring with a 12-lead real-time device and a 2-channel Holter system was performed to detect ischemic episodes. The differences in the number of ischemic events and the total time of ischemia revealed by the two devices were analyzed statistically.

Results: In patients with coronary artery disease, more ischemic ST-segment shifts were detected by the 12-lead device than by Holter monitoring (44 versus 16 events; P < 0.05). Total time of ischemia was also greater with the 12-lead device (879 versus 273 minutes; P < 0.05). Ischemia was detected by both techniques in 6 patients, only by the 12-lead device in 12, and only by Holter monitoring in 1. Neither device detected ischemia in control subjects. The 12-lead device had an advantage in detecting inferior ischemia, and it identified an additional 13 patients with unstable angina who had changes in T-wave polarity but did not exhibit ST-segment shifts.

Conclusion: The 12-lead real-time electrocardiographic monitoring device is superior to Holter monitoring in detecting and facilitating real-time identification of myocardial ischemia in patients at bed rest.