Accurate detection of coronary artery disease by integrated analysis of the ST-segment depression/heart rate patterns during the exercise and recovery phases of the exercise electrocardiography test

Exercise Electrocardiogram Testing

“…23,[87][88][89][90] Data can be examined qualitatively as the simple rate-recovery loop, 91 with findings from the first minute of recovery, when patients with ischemia generally have greater ST-segment depression than was present at the corresponding heart rate during exercise before peak effort ( Figure 2). In contrast to standard ST-depression criteria and heart rate-adjusted criteria derived purely from exercise phase data, the sensitivity of the rate-recovery loop appears to be relatively independent of the extent of disease.…”

“…A relatively simple quantification of the raterecovery loop involves calculation of the ST-segment "deficit" between recovery phase ST depression at 3.5 minutes and the ST depression at the corresponding heart rate during exercise. 89,93 ST/HR hysteresis, as developed by Lehtinen et al, 88,94,95 integrates the area of ST-segment depression with respect to heart rate that is included in the exercise and recovery loop over the heart rate range included in the first 3 minutes of recovery. This integral is then divided by the heart rate difference (ie, the maximum heart rate during exercise minus the minimum heart rate during recovery) of the integration interval to normalize the result with respect to the postexercise heart rate decline.…”

“…88 A recent evaluation by Svensburgh et al 90 has addressed the effect on test performance of the exact range of heart rates included in the rate-recovery area calculation, noting that a large percentage of the loop needs to be considered to optimize diagnosis, especially in women. Bigi et al 96 examined the entire rate-recovery loop by defining a stress-recovery index as the difference in areas under the full exercise and recovery phase ST/HR plots.…”

Refined interpretation of exercise ECG testing: Opportunities for a comeback in the era of expanding advanced cardiac imaging technologies?

“…Analysis of post-exercise ST/HR hysteresis has been shown to provide higher diagnostic and prognostic test accuracy than that found for the standard ST-segment depression criteria and other ST/HR indices. 10,11 Exercise ECG has a much lower specificity in patients with left ventricular hypertrophy in whom false positive tests are frequently observed. [13][14][15] The present study by Zimarino et al shows an enhanced diagnostic accuracy of ST/HR hysteresis in patients with hypertension-related left ventricular hypertrophy and confirms the very low specificity of the classic maximal ST-segment depression criterion that is clinically largely unreliable in detecting significant CAD in those patients.…”

Nonlinear Methods of Cardiovascular Physics and Their Clinical Applicability

“…However more recent studies showed that low amplitude T-wave alternans discriminates patients with ventricular tachycardia (VT) or ventricular fibrillation (VF) from those without VT or VF [Rosenbaum et al, 1996]. The analysis of the ST-segment is a standardized method of ECG analysis, but surprisingly no variability of this segment has been considered so far [Lehtinen et al, 1996;Suurkula et al, 2001]. There are two types of ST-T wave abnormalities which are very common and may be seen in any lead of the ECG: an ST segment depression and an ST segment elevation.…”