DYNAMIC ONLINE VECTORCARDIOGRAPHY IMPROVES AND SIMPLIFIES IN-HOSPITALISCHEMIA MONITORING OF PATIENTS WITH UNSTABLE ANGINA

Objectives. This study sought to validate computerized vectorcardiogra phy against the established technique of Holter electrocardiographic ( EGG) monitoring and to compare the feasibility of the two methods for monitoring patients with unstable angina pectoris. Background. Detecti on of myocardial ischemic episodes is an important objective in patien ts admitted to the hospital for unstable angina pectoris. Standard ECG monitoring may be sufficient for detection of symptomatic episodes bu t will often overlook silent ischemia. Holter ECG monitoring has a hig her likelihood of discovering such episodes, but analysis is time-cons uming, and the results are not available on-line. Methods. We simultan eously monitored 53 consecutive patients with unstable angina, 46 of w hom had technically adequate 24-h Holter ECGs and computerized vectorc ardiograms. Results. The Holter tapes had a mean (+/-SD) of 15.3 +/- 1 0.3 h of recording with both channels technically adequate for analysi s compared with 23.7 +/- 1.77 h of vectorcardiographic recording that could be analyzed (p < 0.01). Of the 15 symptomatic episodes detected by Holter ECG monitoring, 13 were also detected with dynamic vectorcar diography. In contrast, eight patients had 18 episodes of chest pain, with simultaneous ST segment changes detected by dynamic vectorcardiog raphy; only 9 of these episodes were also detected by Holter ECG monit oring. Conclusions. Monitoring of myocardial ischemia with dynamic vec torcardiography seems to be more efficient than Holter monitoring and may have a higher sensitivity. Computerized, continuous vectorcardiogr aphy has a complete real-time capacity, allowing monitoring over prolo nged periods of time, and the results are immediately available withou t time-consuming analysis.