Changes in high-frequency QRS components are more sensitive than ST-segment deviation for detecting acute coronary artery occlusion

OBJECTIVES This study describes changes in high-frequency QRS components (H F-QRS) during percutaneous transluminal coronary angioplasty (PTCA) and com pares the ability of these changes in HF-QRS and ST-segment deviation in th e standard 12-lead electrocardiogram (ECG) to detect acute coronary artery occlusion. BACKGROUND Previous studies have shown decreased HF-QRS in the frequency ra nge of 150-250 Hz during acute myocardial ischemia. II would be important t o know whether the high-frequency analysis could add information to that av ailable from the ST segments in the standard EGG. METHODS The study population consisted of 52 patients undergoing prolonged balloon occlusion during PTCA. Signal-averaged electrocardiograms (SAECG) w ere recorded prior to and during the balloon inflation. The HF-QRS were det ermined within a bandwidth of 150-250 Hz in the preinflation and inflation SAECGs. The ST-segment deviation during inflation was determined in the sta ndard frequency range. RESULTS The sensitivity for detecting acute coronary artery occlusion nas 8 8% using the high-frequency method. In 71% of the patients there was ST ele vation during inflation. If both ST elevation and depression were considere d, the sensitivity was 79%. The sensitivity was significantly higher using the high-frequency method, p < 0.002, compared with the assessment of ST el evation. CONCLUSIONS Acute coronary artery occlusion is detected with higher sensiti vity using high-frequency QPS analysis compared with conventional assessmen t of ST segments. This result suggests that analysis of HF-QRS could provid e an adjunctive tool with high sensitivity for detecting acute myocardial i schemia. (C) 2000 by the American College of Cardiology.