Normal electrocardiographic waveform characteristics during treadmill exercise testing.
1979; Lippincott Williams & Wilkins; Volume: 60; Issue: 5 Linguagem: Inglês
10.1161/01.cir.60.5.1028
ISSN1524-4539
AutoresRoger A. Wolthuis, Victor F. Froelicher, Andrew Hopkirk, Joseph Fischer, N Keiser,
Tópico(s)Cardiovascular Effects of Exercise
ResumoForty asymptomatic male patients at low risk for cardiovascular disease completed maximal treadmill testing. Electrocardiograms from leads CC5, CM5, V5, Yh and Z were recorded across multiple pretest, exercise and recovery conditions. ECG waveforms were subsequently digitized, averaged and processed to provide Q-, R-, S- and T-wave amplitudes, ST-segment means and slopes, and QS- and RT-interval durations. Average R-wave amplitude increased during early exercise and then dramatically decreased to maximum effort. Average S-wave amplitude became greater as exercise progressed. Average J junction was slightly positive before exercise, became negative during exercise (except lead Z) and returned to zero after exercise. The ST-segment slope increased dramatically with progressive exercise. The response of T-wave amplitude, RT and QS intervals are also described. Separately, 22 asymptomatic male subjects each completed two maximal treadmill tests 2 weeks apart. ECG data acquisition and processing were similar to those noted above. Pooled, within-subject estimates of variability were computed for the ECG leads, ECG measurements and protocol conditions. These variability estimates are useful for interpreting ECG responses to exercise testing.
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