ISCHAEMIA DETECTION BY CONTINUOUS ON-LINE VECTORCARDIOGRAPHY AND
12 LEAD ST SEGMENT MONITORING IN ACUTE CORONARY SYNDROMES. B.Aliprandi-Costa*, V.Solanki, B.Freedman Dept of Cardiology, University of Sydney, Concord RG Hospital,
Sydney. BACKGROUND:Detection of ischaemia in acute coronary syndromes identifies
those patients at increased risk of adverse events. Continuous 12
lead and Vectorcardiographic (VCG) monitoring during the initial
24 hrs has an increased sensitivity in the detection of ischaemia
and may provide a more reliable technique for early risk stratification. METHOD: To compare the two methods we prospectively studied 93
patients, mean age 68±14 yrs in CCU with an admission diagnosis
of UA (n=67) or non Q-wave MI (n=26). All patients underwent simultaneous
ST segment monitoring for 24 hrs using continuous on-line vectorcardiography
(VCG) MIDA, and the Mortara 12 lead ST segment monitor (STM). Ischaemia
was defined as reversible deflection of the absolute spatial vector
magnitude (ST-VM) of >50mVs, or any absolute increase in ST change vector
magnitude (STC-VM) of >50mVs of one minute duration, and deviation
of >1mm for 1 min in two contiguous leads for 12 lead STM. RESULTS: Ischaemic episodes were detected in 26 of the 93 patients
by VCG and in 24 patients by the STM. A greater number of ischaemic
episodes were detected by VCG over 24 hrs (n= 66) in comparison
to STM (n=60)(p=ns). The mean duration of individual episodes of
ischaemia did not significantly differ between the two methods.
VCG detected >60 mins of ischaemia in 17 patients and >60mins
of ischaemia was detected on STM in 15 patients CONCLUSIONS:The VCG accurately detects ischaemia in patients with
unstable coronary syndromes, displaying information as a continuous
real time trend and providing a reliable technique to support clinical
decision making.
