Changes in high-frequency QRS components are more sensitive than ST-segment deviation for detecting acute coronary artery occlusion
Jonas Pettersson, MD*,
Olle Pahlm, MD, PhD*,
Elena Carro, MSc*  ,
Lars Edenbrandt, MD, PhD*,
Michael Ringborn, MD*,
Leif Sörnmo, PhD,
Stafford G. Warren, MD and
Galen S. Wagner, MD
* Department of Clinical Physiology, Lund University, Lund, Sweden
Signal Processing Group, Department of Applied Electronics, Lund University, Lund, Sweden
Charleston Area Medical Center, Charleston, West Virginia, USA
Duke University Medical Center, Durham, North Carolina, USA
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Figure 1 Block diagram of the stepwise analysis of the inflation and preinflation recordings. RMS = root-mean-square, SAECG = signal-averaged electrocardiogram.
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Figure 2 Lead V5. Upper panel: Preinflation and inflation SAECGs in the standard frequency range. Lower panel: The same SAECGs within the high-frequency range (150–250 Hz). The amplitude scales are from –700 to +1000 µV for the standard frequency range and –20 to +20 µV for the high-frequency range. The dashed lines indicate the QRS duration, determined from the standard frequency ECG. ECG = electrocardiogram, SAECG = signal-averaged electrocardiogram.
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Figure 3 The percentage of patients (n = 52) meeting the HF-QRS criteria and ST-elevation criteria (panel A) and HF-QRS criteria and ST- elevation/depression criteria (panel B). The numbers outside the circles represent the percentage of patients not meeting any of the criteria. HF-QRS = high-frequency QRS components.
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Figure 4 The percentage of patients with decreased HF-QRS (white bars) and increased HF-QRS (black bars) during inflation in each individual lead. The 37 patients with high-frequency data available from all 12 leads in the LAD (panel A), the LCX (panel B), and the RCA (panel C) groups are presented. HF-QRS = high-frequency QRS components, LAD = left anterior descending coronary artery, LCX = left circumflex coronary artery, RCA = right coronary artery.
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Figure 5 The relationship between the maximal ST elevation in any lead and the maximal decrease in HF-QRS in any lead, r = –0.50 (p = 0.002). In eight of the patients (shadowed area) there were significantly decreased HF-QRS but no significant ST elevation. The 37 patients in the LAD, LCX and RCA groups with high-frequency data available from all 12 leads are presented. HF-QRS = high-frequency QRS components, LAD = left anterior descending coronary artery, LCX = left circumflex coronary artery, RCA = right coronary artery.
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Figure 6 The percentage of patients with the maximal decrease in HF-QRS (black bars) and the maximal ST-elevation (white bars) in each individual lead. The 37 patients with high-frequency data available from all 12 leads in the LAD (panel A), the LCX (panel B), and the RCA (panel C) groups are presented. HF-QRS = high-frequency QRS components, LAD = left anterior descending coronary artery, LCX = left circumflex coronary artery, RCA = right coronary artery.
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Figure 7 Trends of ST-segment level (upper panel) and HF-QRS (lower panel) during a 5-min LCX occlusion. The leads I and III are shown. The balloon was inflated at time 0. There was ST elevation (>0.1 mV) in lead III but no significant ST deviation in lead I. In both these leads there was a significant decrease in HF-QRS. HF-QRS = high-frequency QRS components, LCX = left circumflex coronary artery.
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