Infarct‐like Acute Myocarditis: Relation Between Electrocardiographic Findings and Myocardial Damage as Assessed by Cardiac Magnetic Resonance Imaging

Abstract

Background: Acute myocarditis (AM) may occasionally have an infarct-like presentation. The aim of the present study was to investigate the relation between electrocardiographic (ECG) findings in this group of patients and myocardial damage assessed by cardiac magnetic resonance imaging (MRI) with the late gadolinium enhancement (LGE) technique. Hypothesis: Myocardial damage may be associated with ECG changes in infarct-like AM. Methods: Forty-one consecutive patients (36 males; mean age, 36 ± 12 years) with diagnosis of AM according to cardiac MRI Lake Louise criteria and infarct-like presentation were included. The relation between site of ST-segment elevation (STE), sum of STE (sumSTE), time to normalization of STE, and development of negative T wave with the extent of LGE (expressed as % of left ventricular mass [%LV LGE]), was evaluated. Results: Most (80%) patients presented with inferolateral STE; mean sumSTE was 5 ± 3 mm. Normalization of STE occurred within 24 hours in 20 (49%) patients. Development of negative T wave occurred in 28 (68%) patients. Cardiac MRI showed LGE in all patients; mean %LV LGE was 9.6 ± 7.2%. Topographic agreement between site of STE and LGE was 68%. At multivariate analysis, sumSTE (β = 0.42, P < 0.001), normalization of STE >24 hours (β = 0.39, P < 0.001), and development of negative T wave (β = 0.49, P < 0.001) were independently related to %LV LGE. Conclusions: Analysis of the site of STE underestimates the extent of myocardial injury among patients with infarct-like myocarditis. However, some ECG features (ie, sumSTE, normalization of STE >24 hours, and development of negative T wave) may help to identify patients with larger areas of myocardial damage.

Diagnostic and prognostic role of electrocardiogram in acute myocarditis: A comprehensive review

“…A clear territorial distribution on ECG is not always visible. No strict correlation was found between location of ST elevation on surface ECG and areas of distribution of necrosis/scar as assessed by MRI in LGE sequences (Deluigi et al, 2013;Di Bella et al, 2012;Nucifora et al, 2013). A study by Karjalainen et al showed that, in young men with ACS-like myocarditis, patients with larger extension of myocardial damage (as assessed by peak creatine kinase MB value) had higher maximum ST elevation in a single lead (Karjalainen & Heikkilä, 1986).…”

Infectious myocarditis: the role of the cardiac vasculature

“…[ 91 – 93 ] Infectious myocarditis patients can present with additional infarct-like symptoms such as ST-segment elevation on ECG, wall motion abnormalities, and elevated circulating cardiac troponin levels. [ 94 , 95 ] However, despite the similarities in clinical presentation, infectious myocarditis and myocardial infarction are generally considered as distinct clinical entities.…”

Evaluation of heart rate variability and behavior of electrocardiographic parameters in dogs affected by chronic Monocytic Ehrlichiosis

“…Even though ventricular tachycardia is often associated with a poor prognosis in human cases of myocarditis caused by Chagas disease, and with increased risk of sudden death [37], the presence of major arrhythmias was not considered a risk factor for the animals who died in this study since the animal that presented severe arrhythmias survived for the entire 28-day follow up period.…”