Assessment of Myocardial Infarct Size with Body Surface Potential Mapping: Validation against Contrast-Enhanced Cardiac Magnetic Resonance Imaging

• Published in: Annals of noninvasive electrocardiology Vol. 20; no. 3; pp. 240 - 252
• Main Authors: Kylmälä, Minna M., Konttila, Teijo, Vesterinen, Paula, Kivistö, Sari M., Lauerma, Kirsi, Lindholm, Mats, Väänänen, Heikki, Stenroos, Matti, Nieminen, Markku S., Hänninen, Helena, Toivonen, Lauri
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-05-2015; John Wiley & Sons, Inc; John Wiley and Sons Inc
• Subjects: Body Surface Potential Mapping; cardiac magnetic resonance imaging; Contrast Media; Electrocardiography; Female; Heart - physiopathology; Heart attacks; Humans; Image Enhancement - methods; Magnetic Resonance Imaging; Male; Middle Aged; myocardial infarct size; myocardial infarction; Myocardial Infarction - diagnosis; Myocardial Infarction - pathology; Myocardial Infarction - physiopathology; Myocardium - pathology; Original; Reproducibility of Results; ROC Curve; Severity of Illness Index; body surface potential mapping; cardiac magnetic resonance imaging; myocardial infarction; electrocardiography; myocardial infarct size
• ISSN: 1082-720X; 1542-474X
• DOI: 10.1111/anec.12198

Background
Assessment of myocardial infarct (MI) size is important for therapeutic and prognostic reasons. We used body surface potential mapping (BSPM) to evaluate whether single‐lead electrocardiographic variables can assess MI size.
Methods
We performed BSPM with 120 leads covering the front and back chest (plus limb leads) on 57 patients at different phases of MI: acutely, during healing, and in the chronic phase. Final MI size was determined by contrast‐enhanced cardiac magnetic resonance imaging (DE‐CMR) and correlated with various computed depolarization‐ and repolarization‐phase BSPM variables. We also calculated correlations between BSPM variables and enzymatic MI size (peak CK‐MBm).
Results
BSPM variables reflecting the Q‐ and R wave showed strong correlations with MI size at all stages of MI. R width performed the best, showing its strongest correlation with MI size on the upper right back, there representing the width of the “reciprocal Q wave” (r = 0.64–0.71 for DE‐CMR, r = 0.57–0.64 for CK‐MBm, P < 0.0001). Repolarization‐phase variables showed only weak correlations with MI size in the acute phase, but these correlations improved during MI healing. T‐wave variables and the QRSSTT integral showed their best correlations with DE‐CMR defined MI size on the precordial area, at best r = −0.57, P < 0.0001 in the chronic phase. The best performing BSPM variables could differentiate between large and small infarcts at all stages of MI.
Conclusions
Computed, single‐lead electrocardiographic variables can estimate the final infarct size at all stages of MI, and differentiate large infarcts from small.