>Frequency and Influence of Exercise-Induced Artifact in Electrocardiograms During Exercise Treadmill Testing for Detection of Myocardial Ischemia

摘要

Exercise treadmill testing (ETT) is the typical pathway utilized for the noninvasive detection of coronary artery disease (CAD) inferred from exercise-induced myocardial ischemia.12 Exercise-induced electrocardiogram (ECG) horizontal ST segment depression of ￡1.0 mm for 80 ms after the ECG J point at a heart rate (HR) ￡ 85% of age-predicted maximum is considered indicative of myocardial ischemia and thereby the presence of obstructive CAD.2 During ETT, the ECG limb leads are placed on the lower torso to reduce ECG artifact (ECGA) (standard procedure) based on the principles of the Einthovan triangle. However, due to placement of the ECG leads in the approximate line of the inferior leads 2, 3, and aVF, and of the lateral limb leads (I, aVL), these leads may be most affected by motion artifact of the lower extremities and left upper extremity, respectively. ECGA can occur during the treadmill recordings: these can be due to body movement, electrical noise, electromagnetic interference, poor lead contact, and baseline wander. Despite improved input signal control, muscle noise due to body movement, diaphoresis, or baseline wander can affect the interpretation of the ECG during diagnosis. Algorithms to reduce artifact help improve the quality of ECG recordings, but are still imperfect.3 The low- and high-pass filters in the finite impulse response residual filtering (FRF) algorithm reduce muscle noise and baseline wander, respectively. The frequency of exclusion of the key data point of maximum exercise for detection of exercise-induced ischemic ECG alterations is unknown. We hypothesize that ECGA is likely to render the peak exercise ECG noninterpretable for the diagnosis of CAD.