Detection of coronary artery stenosis after successful percutaneous coronary intervention by dipyridamole stress portable type signal-averaged electrocardiography: a prospective study

In our previous studies, using portable type signalaveraged electrocardiography (portable SAECG) with dipyridamole stress we reported that patients with coronary artery disease were identified at the bedside with high sensitivity and specificity. In this study we prospectively investigated whether coronary artery stenosis after successful percutaneous coronary intervention (PCI) could be detected. Standard 12-lead QRS wave SAECG was performed before and after dipyridamole stress at the bedside in 61 patients 8.0 ± 9.4 months after successful PCI for myocardial infarction or angina pectoris (46 males and 15 females, mean age 66 ± 12 years). The filtered QRS duration (fQRSd) before and after dipyridamole stress was determined by the multiphasic oscillation method at each lead of the standard 12 leads, and the maximal value of changes in fQRSd (MAX ΔfQRSd) among the 12 leads was determined. The positive test was defined as MAX ΔfQRSd ≥5 ms, and negative as MAX ΔfQRSd <5 ms based on our previous studies. Then selective coronary arteriography was performed. In the positive group (n = 24), 21 patients had stenosis (≥50%) of the coronary artery and 3 did not. In the negative group (n = 37), 8 patients had stenosis and 29 did not. The sensitivity, specificity, positive predictive accuracy, and negative predictive accuracy for the detection of coronary artery stenosis by SAECG were 72%, 91%, 88%, and 78%, respectively. Dipyridamole stress portable SAECG is useful to detect patients with coronary artery stenosis after successful PCI.