Key result
Magnetocardiography RMS40 ≤ 0.24 is linked to ~11-fold higher odds of prior VF.
Why the study?
Although the early repolarization pattern in ECG poses a risk for ventricular fibrillation, effective methods to identify malignant early repolarization pattern are still required.
Does high-resolution magnetocardiography improve the identification of malignant early repolarization patterns compared to standard ECG in patients with early repolarization pattern and no structural heart disease?
Observational (n=116)
No
Does high-resolution magnetocardiography improve the identification of malignant early repolarization patterns compared to standard ECG in patients with early repolarization pattern and no structural heart disease?
Effect estimate: OR 10.9 (95% CI 1.37-86.8)
p-value: p=0.01
High-resolution magnetocardiography parameters (MCG-QRSD and MCG-RMS40) can effectively distinguish malignant from benign early repolarization patterns better than standard ECG J-peak amplitude.
May aid identification of high-risk early repolarization; hypothesis-generating and requires prospective validation before clinical adoption.
BACKGROUND: The early repolarization pattern (ERP) in electrocardiography (ECG) has been considered as a risk for ventricular fibrillation (VF), but effective methods for identification of malignant ERP are still required. We investigated whether high spatiotemporal resolution 64-channel magnetocardiography (MCG) would enable distinction between benign and malignant ERPs. METHODS: Among all 2,636 subjects who received MCG in our facility, we identified 116 subjects (43 ± 18 years old, 54% male) with inferior and/or lateral ERP in ECG and without structural heart disease, including 13 survivors of VF (ERP-VF(+)) and 103 with no history of VF (ERP-VF(-)). We measured the following MCG parameters in a time-domain waveform of relative current magnitude: (a) QRS duration (MCG-QRSD), (b) root-mean-square of the last 40 ms (MCG-RMS40), and (c) low amplitude (<10% of maximal) signal duration (MCG-LAS). RESULTS: Compared to ERP-VF(-), ERP-VF(+) subjects presented a significantly longer MCG-QRS (108 ± 24 vs. 91 ± 23 ms, p = .02) and lower MCG-RMS40 (0.10 ± 0.08 vs. 0.25 ± 0.20, p = .01) but no difference in MCG-LAS (38 ± 22 vs. 29 ± 23 ms, p = .17). MCG-QRSD and MCG-RMS40 showed significantly larger area under the ROC curve compared to J-peak amplitude in ECG (0.72 and 0.71 vs. 0.50; p = .04 and 0.03). The sensitivity, specificity, and odds ratio for identifying VF(+) based on MCG-QRSD ≥ 100 ms and MCG-RMS40 ≤ 0.24 were 69%, 74%, and 6.33 (95% CI, 1.80-22.3), and 92%, 48%, and 10.9 (95% CI, 1.37-86.8), respectively. CONCLUSION: Magnetocardiography is an effective tool to distinguish malignant and benign ERPs.
No takes yet. Share an insight, caveat, or question.
Iwakami et al. (2020) conducted an observational in Early repolarization pattern (ERP) (n=116). High-resolution 64-channel magnetocardiography (MCG) vs. ERP-VF(-) subjects was evaluated on Identification of VF(+) based on MCG-RMS40 ≤ 0.24 (OR 10.9, 95% CI 1.37-86.8, p=0.01). High-resolution magnetocardiography identified malignant early repolarization patterns, with MCG-RMS40 ≤ 0.24 strongly associated with a history of ventricular fibrillation (OR 10.9; 95% CI 1.37-86.8).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: