Acute myocarditis mimicking ST-elevation myocardial infarction: A case report and review of the literature

Development and Validation of a Prediction Model on Adult Emergency Department Patients for Early Identification of Fulminant Myocarditis

OBJECTIVE

It is difficult to predict fulminant myocarditis at an early stage in the emergency department. The objective of this study was to construct and validate a simple prediction model for the early identification of fulminant myocarditis.

METHODS

A total of 61 patients with fulminant myocarditis and 160 patients with acute myocarditis were enrolled in the training and internal validation cohorts. LASSO regression and multivariate logistic regression were selected to develop the prediction model. The selection of the model was based on overall performance and simplicity. A nomogram based on the optimal model was built, and its clinical usefulness was evaluated by decision curve analysis. The predictive model was further validated in an external validation group.

RESULTS

The resulting prediction model was based on 4 factors: systolic blood pressure, troponin I, left ventricular ejection fraction, and ventricular wall motion abnormality. The Brier scores of the final model were 0.078 in the training data set and 0.061 in the internal testing data set, respectively. The C-indexes of the training data set and the testing data set were 0.952 and 0.968, respectively. Decision curve analysis showed that the nomogram model developed based on the 4 predictors above had a positive net benefit for predicting probability thresholds. In the external validation cohort, the model also showed good performance (Brier score=0.007, and C-index=0.989).

CONCLUSION

We developed and validated an early prediction model consisting of 4 clinical factors (systolic blood pressure, troponin I, left ventricular ejection fraction, and ventricular wall motion abnormality) to identify potential fulminant myocarditis patients in the emergency department.

Acute Perimyocarditis - an ST-Elevation Myocardial Infarction Mimicker: A Case Report

BACKGROUND A normal coronary angiogram in ST-elevation myocardial infarction (STEMI) can be considered a myocardial infarction with non-obstructive coronary arteries (MINOCA) until an alternative diagnosis is obtained. However, the COVID-19 pandemic might delay urgent coronary angiography in a resource-limited setting. Perimyocarditis often causes symptoms, such as chest pain, as well as ST-elevation and high cardiac troponin levels. This STEMI mimicker can also cause cardiogenic shock and death when not treated properly. CASE REPORT A 40-year-old man reported having acute onset of substernal chest pain, which was suspected to be STEMI. The patient was an active smoker without any risk factors or a history of cardiovascular disease. The examination showed elevated cardiac troponin I, ST-elevation in high lateral leads, and regional wall motion abnormality (RWMA) by echocardiogram. Furthermore, thrombolytic therapy had failed, and rescue percutaneous coronary intervention was not performed due to the catheterization laboratory limitation during the COVID-19 pandemic. Before coronary angiography, the patient was scheduled for 2 consecutive days of COVID-19 polymerase chain reaction (PCR) swabs. On the second day of hospitalization, the patient experienced a cardiogenic shock. The COVID-19 PCR results were negative, while coronary angiography revealed normal coronary arteries. The patient was eventually diagnosed with probable acute perimyocarditis. CONCLUSIONS Myocarditis is implicated in young patients without typical cardiovascular risk factors or in those with recent infection and cardiovascular symptoms mimicking acute coronary syndrome. It might also be present in situations where ST-elevation distribution on the electrocardiogram is discordant with the RWMA observed on the echocardiogram.

The Diagnostic Role of Echocardiographic Strain Analysis in Patients Presenting with Chest Pain and Elevated Troponin: A Multicenter Study

BACKGROUND

Myocarditis presenting as acute chest pain with elevated troponins without significant cardiac compromise is rare in previously healthy children, often referred to as myopericarditis. Diagnosis is challenging as conventional echocardiographic measures of systolic function can be normal. This study aimed to demonstrate the diagnostic utility of strain imaging in this scenario.

METHODS

This is a multi-center retrospective study including patients presenting with chest pain and elevated troponin from 10 institutions who underwent cardiac MRI (CMR) and transthoracic echocardiogram (echo) within 30 days of each other (group 1). Findings were compared to 19 controls (group 2). Clinical data, conventional echo and CMR data were collected. Echo-derived strain was measured at the core lab. Group 1 was divided into subgroups as CMR myocarditis positive (group 1a) or negative (group 1b) based on established criteria.

RESULTS

Group 1 included 108 subjects (88 in group 1a, 20 in group 1b). While all groups had normal mean fractional shortening (FS) and mean left ventricular ejection fraction (LVEF), group 1 had significantly lower EF (56.8+/-7.0) compared to group 2 ( 62.3+/- 4.9, P<0.005) and FS (31.2+/- 4.9) compared to group 2 (34.1+/-3.5, p<0.05). Additionally, peak global longitudinal strain (GLS%) was markedly abnormal in group 1 (-13.9+/-3.4 ) compared to group 2 (-19.8+/-2.1 , P<0.001). In subgroup analysis, GLS% was markedly abnormal in group 1a (-13.2 ± 3.0%) compared to group 1b (-17.3 ± 2.6% and p<0.001). Fifty-four subjects had follow up echocardiograms (46 in group 1a, 8 in group 1b) with mean follow-up time of 10 months (SD=11 months). At follow up, while EF and FS returned to normal in all patients, abnormalities in strain persisted in group 1, with 22% of them still having abnormal GLS. Moreover, mean GLS was more abnormal in group 1a (-16.1 +/- 2.6) compared to group 1b (-17.4+/- 1.2, p<0.05).

CONCLUSIONS

Our study demonstrates that echo GLS% is significantly worse in subjects with myopericarditis presenting with chest pain and elevated troponins compared to controls even when conventional measures of systolic function are largely normal and that these abnormalities persisted overtime.

The effect of coenzyme Q10 plus trimetazidine on acute viral myocarditis treatment

OBJECTIVE

To investigate the clinical efficacy of coenzyme Q10 (CoQ10) plus trimetazidine (TMZ) in treating acute viral myocarditis (AVMC) and the combination's influence on the oxidative stress markers and the patients' quality of life (QoL).

METHODS

This retrospective analysis enrolled 156 patients with AVMC admitted to the Department of Cardiology of the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine between February 2018 and February 2019. Based on the treatment method each patient was administered, the patients were classified into a control group (n=72, CoQ10 therapy) and a combination group (n=84, CoQ10+TMZ therapy). The clinical effectiveness was observed in the two groups two weeks after the treatment, and the changes in the patients' serum inflammatory factor levels, oxidative stress indexes, myocardial enzyme levels, and cardiac function were compared.

RESULTS

The combination group had a far superior total effective rate than the control group (90.5% vs. 77.8%, P<0.05). After the treatment, the serum inflammatory factor levels, including tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), and C-reactive protein (CRP), decreased in both groups, and the index levels in the combination group were significantly better than they were in the control group (P<0.05). The oxidative stress indicators, such as superoxide dismutase (SOD), malondialdehyde (MDA) and nitric oxide (NO), improved more significantly in the combination group compared to the control group (P<0.05). The myocardial zymogram creatine kinase (CK), cardiac troponin (cTnI), creatine kinase isoenzyme MB (CK-MB), and lactate dehydrogenase (LDH) levels were reduced in the two groups, with lower levels in the combination group. The left ventricular systolic function and the patients' QoL were better in the combination group compared with the control group (P<0.05).

CONCLUSIONS

CoQ10 plus TMZ yields a favorable clinical effectiveness in the treatment of AVMC, and it can effectively promote cardiac function recovery, alleviate oxidative stress and inflammatory reactions, and bolster patients' QoL.

Acute Myocardial Infarction Detection Using Deep Learning-Enabled Electrocardiograms

Background: Acute myocardial infarction (AMI) is associated with a poor prognosis. Therefore, accurate diagnosis and early intervention of the culprit lesion are of extreme importance. Therefore, we developed a neural network algorithm in this study to automatically diagnose AMI from 12-lead electrocardiograms (ECGs). Methods: We used the open-source PTB-XL database as the training and validation sets, with a 7:3 sample size ratio. Twenty-One thousand, eight hundred thirty-seven clinical 12-lead ECGs from the PTB-XL dataset were available for training and validation (15,285 were used in the training set and 6,552 in the validation set). Additionally, we randomly selected 205 ECGs from a dataset built by Chapman University, CA, USA and Shaoxing People's Hospital, China, as the testing set. We used a residual network for training and validation. The model performance was experimentally verified in terms of area under the curve (AUC), precision, sensitivity, specificity, and F1 score. Results: The AUC of the training, validation, and testing sets were 0.964 [95% confidence interval (CI): 0.961-0.966], 0.944 (95% CI: 0.939-0.949), and 0.977 (95% CI: 0.961-0.991), respectively. The precision, sensitivity, specificity, and F1 score of the deep learning model for AMI diagnosis from ECGs were 0.827, 0.824, 0.950, and 0.825, respectively, in the training set, 0.789, 0.818, 0.913, and 0.803, respectively, in the validation set, and 0.830, 0.951, 0.951, and 0.886, respectively, in the testing set. The AUC for automatic AMI location diagnosis of LMI, IMI, ASMI, AMI, ALMI were 0.969 (95% CI: 0.959-0.979), 0.973 (95% CI: 0.962-0.978), 0.987 (95% CI: 0.963-0.989), 0.961 (95% CI: 0.956-0.989), and 0.996 (95% CI: 0.957-0.997), respectively. Conclusions: The residual network-based algorithm can effectively automatically diagnose AMI and MI location from 12-lead ECGs.

A Rare Case of Myocarditis Mimicking ST-Elevation Myocardial Infarction

Myocarditis is caused by acute injury and inflammation of cardiac myocytes and is most commonly caused by a viral infection. Myocarditis remains a rare diagnosis and manifests with a wide spectrum of non-specific symptoms that include chest pain, dyspnea, and palpitations associated with electrocardiographic abnormalities that resemble that of ST-elevation myocardial infarction (STEMI). Therefore, clinical diagnosis is often challenging and is often misdiagnosed. We present a case of a 22-year-old male who presented with left-sided non-radiating chest pain associated with shortness of breath, elevated troponin of 3.2 ng/ml (<0.03 ng/ml). Electrocardiogram (ECG) and cardiac echocardiogram revealed ST-segment elevations in the anterolateral leads and an ejection fraction of 35%, respectively. The patient was initially suspected of having a STEMI; however, cardiac catheterization revealed non-obstructed coronary arteries. Due to elevated inflammatory markers, the patient was then started on colchicine for suspected myocarditis and had complete resolution of symptoms one week after. This case highlights that a high index of clinical suspicion and prompt diagnosis is necessary to prevent any delays in appropriate therapy for myocarditis.

A Case of Acute Myocardial Injury – MINOCA or Myocarditis?

Myocardial infarction with non-obstructive coronary arteries (MINOCA) has been defined as clinical presentation of an acute coronary syndrome with laboratory evidence of myocardial necrosis, but with coronary stenosis of less than 50% on coronary angiography. On the other side, myocarditis is an inflammatory response triggered by viral, bacterial, fungal, lymphocytic, eosinophilic, or autoimmune myocardial injury, which may be associated with elevated myocardial necrosis serum biomarkers. We present the case of a young male patient with acute chest pain, ST-segment elevation, and high-sensitivity troponin levels of 22,162 ng/L.

Diagnostic role of strain imaging in atypical myocarditis by echocardiography and cardiac MRI

BACKGROUND

The diagnosis of myocarditis presenting as isolated acute chest pain with elevated troponins but normal systolic function is challenging with significant drawbacks even for the gold-standard endomyocardial biopsy.

OBJECTIVE

This study aimed to evaluate the diagnostic role of strain imaging by echocardiography and cardiac MRI in these patients.

MATERIALS AND METHODS

This was a retrospective review of children with cardiac MRI for acute chest pain with elevated troponins compared to normal controls. Echocardiographic fractional shortening, ejection fraction, speckle-tracking-derived peak longitudinal, radial, and circumferential strain were compared to cardiac MRI ejection fraction, T2 imaging, late gadolinium enhancement, speckle-tracking-derived peak longitudinal strain, radial strain, and circumferential strain.

RESULTS

Group 1 included 10 subjects diagnosed with myocarditis, 9 (90%) males with a median age of 15.5 years (range: 14-17 years) compared with 10 age-matched controls in group 2. All subjects in group 1 had late gadolinium enhancement consistent with myocarditis and troponin ranged from 2.5 to >30 ng/ml. Electrocardiogram changes included ST segment elevation in 6 and abnormal Q waves in 1. Qualitative echocardiographic function was normal in both groups and mean fractional shortening was similar (35±6% in group 1 vs. 34±4% in group 2, P=0.70). Left ventricle ejection fraction by cardiac MRI, however, was lower in group 1 (52±9%) compared to group 2 at (59±4%) (P=0.03). Cardiac MRI derived strain was lower in group 1 vs. group 2 for speckle-tracking-derived peak longitudinal strain (-12.8±2.8% vs. -17.1±1.5%, P=0.001), circumferential strain (-12.3±3.8% vs. -15.8±1.2%, P=0.020) and radial strain (13.6±3.7% vs. 17.2±3.2%, P=0.040). Echocardiography derived strain was also lower in group 1 vs. group 2 for speckle-tracking-derived peak longitudinal strain (-15.6±3.9% vs. -20.8±2.2%, P<0.002), circumferential strain (-16±3% vs. -19.8±1.9%, P<0.003) and radial strain (17.3±6.1% vs. 24.8±6.3%, P=0.010).

CONCLUSION

In previously asymptomatic children, myocarditis can present with symptoms of acute chest pain suspicious for coronary ischemia. Cardiac MRI and echocardiographic strain imaging are noninvasive, radiation-free tests of immense diagnostic utility in these situations. Long-term studies are needed to assess prognostic significance of these findings.

Infant acute myocarditis mimicking acute myocardial infarction

Myocarditis is an inflammatory disease of the myocardium with heterogeneous clinical manifestations and progression. In clinical practice, although there are many methods of diagnosis of acute myocarditis, the diagnosis remains an embarrassing dilemma for clinicians. The authors report the case of 9-month-old infant who was brought to the Pediatric Emergency Department with sudden onset dyspnea. Examination disclosed heart failure and resuscitation was undertaken. The electrocardiogram showed an ST segment elevation in the anterolateral leads with a mirror image. Cardiac enzyme tests revealed a significant elevation of troponin and creatine phosphokinase levels. A diagnosis of acute myocardial infarction was made, and heparin therapy was prescribed. The infant died on the third day after admission with cardiogenic shock. The autopsy showed dilatation of the ventricles and massive edema of the lungs. Histological examinations of myocardium samples revealed the presence of a marked lymphocytic infiltrate dissociating myocardiocytes. Death was attributed to acute myocarditis. The authors call attention to the difficulties of differential diagnosis between acute myocarditis and acute myocardial infarction especially in children, and to the important therapeutic implications of a correct diagnosis.