Computerized vectorcardiography telemetry: a new device for continuous multilead ST-segment monitoring of ambulatory patients. A preliminary report.
BACKGROUND
Continuous vectorcardiography ST-segment monitoring has become a well-established method in the surveillance of patients with acute myocardial ischemia. However, immobility of the vectorcardiography technique prevents monitoring of patients during ambulatory activities. Computerized vectorcardiography telemetry (CVT) with the capacity of real-time ST-segment analysis has been developed in an attempt to overcome this shortcoming. Recent data, however, indicate that changes in body position occasionally lead to pseudo-ischemic ST-segment changes during continuous ST-segment monitoring.


OBJECTIVE
This report describes the technical features of the CVT system, presents clinical examples using CVT, and assesses the influence of changes in body position on ST-vector magnitude (ST-VM) during CVT, respectively.


METHODS
Clinical cases involving CVT are presented. The influence of changing body position during CVT monitoring was evaluated on 24 patients with suspected acute coronary syndromes, i.e., unstable angina or acute myocardial infarction. Each patient performed a specific body positional schedule.


RESULTS
We present three discrete clinical cases where CVT provided early and valuable evidence of ongoing myocardial ischemia. The consequences of different recumbent and ambulatory body positions on ST-VM during CVT monitoring appear to be limited.


CONCLUSIONS
Computerized vectorcardiography telemetry is a promising new tool for disclosing residual myocardial ischemic activity during the mobilization phase of patients with acute coronary syndromes. The clinical value of CVT needs further investigation in future trials.
Nørgaard
Bjarne Linde
BL
Department of Medicine and Cardiology A, Aarhus University Hospital, Denmark.
Sørensen
Claus
C
Larsen
Thomas
T
Thygesen
Kristian
K
Dellborg
Mikael
M
D000789:Angina, Unstable / Q000175:diagnosis* / Q000503:physiopathology; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology; D011187:Posture; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013686:Telemetry / Q000379:methods*; D014672:Vectorcardiography / Q000295:instrumentation / Q000379:methods*