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Comparison of Electrocardiogram and Intrathoracic Electrogram Signals for Detection of Ischemic ST Segment Changes During Normal Sinus and Ventricular Paced Rhythms
Author(s) -
THERES HEINZ,
STADLER ROBERT W.,
STYLOS LEE,
GLOS MARTIN,
LEUTHOLD THOMAS,
BAUMANN GERT,
NELSON SHAN D.,
KRUCOFF MITCHEL W.
Publication year - 2002
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1046/j.1540-8167.2002.00990.x
Subject(s) - medicine , cardiology , qrs complex , sinus rhythm , electrocardiography , percutaneous transluminal coronary angioplasty , atrial fibrillation , angioplasty
ST Segment Changes in ECG and EGM Signals.Introduction : The aim of this study was to compare surface ECGs with electrograms (EGM) that are available from implanted devices for the ability to detect ischemic ST segment changes during normal sinus (NS) and ventricular paced (VP) rhythms. Methods and Results : ECG leads I, II, and V 2 , right atrial ring to left pectoral patch (representing the can of the device), right ventricular ring to left pectoral patch, and right atrial ring to right ventricular ring EGM were recorded continuously during percutaneous transluminal coronary angioplasty. One balloon inflation ( ≥ 60 sec) was analyzed from each of 22 NS and 22 VP subjects. The parameter ΔST was defined as the maximum absolute ST segment deviation (from isoelectric) during the first 60 seconds of inflation, measured relative to the baseline (preinflation) ST segment deviation. For EGM, a normalized ΔST was defined as the ΔST divided by the ratio of QRS amplitudes of EGM to ECG. During NS, the ΔST for EGM (0.43 mV) was significantly larger than that of ECG ( 0.09 mV, P = 0.0001 ) but the normalized ΔST for EGM (0.11 mV) was comparable to that of ECG ( 0.09 mV, P = 0.45 ). During VP, the ΔST for EGM (1.08 mV) was significantly larger than that of ECG ( 0.17 mV, P = 0.0001 ), but the normalized ΔST for EGM (0.11 mV) was significantly smaller than that of ECG ( 0.17 mV, P = 0.02 ). Conclusion : During both NS and VP, ischemic ST segment changes were significantly larger in EGM than in ECG. Much of this difference appears to be related to larger amplitudes of EGM signals.