The diagnostic capability of electrocardiography on the cardiogenic shock in the patients with acute myocarditis

Update on Myocarditis: From Etiology and Clinical Picture to Modern Diagnostics and Methods of Treatment

Although the frequency of myocarditis in the general population is very difficult to accurately determine due to the large number of asymptomatic cases, the incidence of this disease is increasing significantly due to better defined criteria for diagnosis and the development of modern diagnostic methods. The multitude of different etiological factors, the diversity of the clinical picture, and the variability of the diagnostic findings make this disease often demanding both for the selection of the diagnostic modality and for the proper therapeutic approach. The previously known most common viral etiology of this disease is today overshadowed by new findings based on immune-mediated processes, associated with diseases that in their natural course can lead to myocardial involvement, as well as the iatrogenic cause of myocarditis, which is due to use of immune checkpoint inhibitors in the treatment of cancer patients. Suspecting that a patient with polymorphic and non-specific clinical signs and symptoms, such as changes in ECG and echocardiography readings, has myocarditis is the starting point in the diagnostic algorithm. Cardio magnetic resonance imaging is non-invasive and is the gold standard for diagnosis and clinical follow-up of these patients. Endomyocardial biopsy as an invasive method is the diagnostic choice in life-threatening cases with suspicion of fulminant myocarditis where the diagnosis has not yet established or there is no adequate response to the applied therapeutic regimen. The treatment of myocarditis is increasingly demanding and includes conservative methods of treating heart failure, immunomodulatory and immunospressive therapy, methods of mechanical circulatory support, and heart transplantation. The goal of developing new diagnostic and therapeutic methods is to reduce mortality from this complex disease, which is still high.

Q wave in paediatric myocarditis: an underinvestigated, readily available prognostic factor

BACKGROUND

Myocarditis is an uncommon disease in children with potentially fatal consequences. An electrocardiogram (ECG) change seen in myocarditis is pathological Q wave. Pathological Q wave is linked to permanent damage and myocardial death in several cardiac diseases. We investigated the significance of pathological Q waves in children with acute myocarditis (AM).

METHODS

This retrospective observational study analysed the data of 59 children with AM admitted to our hospital between January 2016 and July 2021. They were divided into Q wave and non-Q wave myocarditis groups. Patients' laboratory data, echocardiography, treatment and hospital outcome were analysed.

RESULTS

Patients were 64.4% male and had a median age of 6 years and 9 months. Pathological Q waves were found in 52.5% of the patients. Q wave myocarditis group had higher troponin I values (499 vs. 145 ng/L, p = 0.011) and longer hospital stays (13 vs. 9 days, p = 0.020) than the non-Q wave group. They also required higher doses of inotropic or vasoactive drugs. 61.3% of Q wave patients needed mechanical ventilation compared to 35.7% of non-Q wave patients (p = 0.069). All the patients who died or discharged with an LVEF < 30% belonged to the Q wave group.

CONCLUSION

Q wave in AM warrants close monitoring and intensive treatment as it accompanies more severe complications and poorer outcomes. This readily available ECG finding can be a clue to prognoses of AM patients. Further research with larger populations is needed to better understand Q wave prognostic accuracy and its potential role in guiding more expensive treatments.

Clinical and electrocardiographic characteristics in patients with fulminant myocarditis

Background

The purpose of this study was to evaluate clinical and electrocardiographic characteristics in patients with fulminant myocarditis.

Methods

A total of 72 patients were divided into three groups: pericarditis (control: n = 25), acute myocarditis (n = 27), and fulminant myocarditis (n = 20). Patients' characteristics and electrocardiograms on admission were retrospectively analyzed in the three groups.

Results

BNP levels in the fulminant group were significantly higher than those in the other two groups. ST elevation was observed at lead aVR in the fulminant myocarditis group, whereas ST depression was observed at lead aVR in the other groups (p = .001). The maximum degree of ST elevation among the three groups was similar. However, the number of ST‐elevation leads in the fulminant myocarditis group was significantly lower than that in the other groups (p = .004). The voltage of R wave in lead V5 in the fulminant myocarditis group was significantly lower than that in the other groups (p = .005). Moreover, in the Cabrera sequence, the prevalence of ST elevation in the inferior leads, aVR, and V3–V6 in the fulminant myocarditis group was significantly or nearly significantly lower than that in the other groups.

Conclusions

In fulminant myocarditis, ST‐segment elevation was observed in lead aVR, and contrarily, the number and extent of ST‐segment elevation and R wave voltage were smaller than those in the other groups. These results suggest that the number of myocytes with maintained action potential may be reduced following progressive myocardial damage and interstitial edema due to severe inflammation.

Clinical analysis of temporary pacemaker implantation in 13 children

BACKGROUND

At present, temporary pacemaker implantation is very common in the treatment of cardiovascular diseases in adults. However, the number of pediatric pacemakers implanted is still relatively small, and relevant research is also far less than that of adults. This study aimed to explore the application of temporary pacemakers in children with acute and critical cardiovascular diseases.

METHODS

The clinical data of children with cardiovascular diseases who were treated with temporary pacemakers in Tianjin Children's Hospital from October 2017 to February 2021 were analyzed retrospectively.

RESULTS

A total of 13 children with cardiovascular diseases were included in this study, including 4 males and 9 females, mean age of 71.2±56.3 months, and median body weight of 15.5 kg. There were 9 children with endocardial pacing and 4 children with epicardial pacing. The types of diseases included fulminant myocarditis (n=8), complete atrioventricular block (CAVB; n=1), and arrhythmias after open heart surgery (n=4). The median time from onset to admission was 1.0 days in children with endocardial pacing and there was cardiac arrest in 2 children, heart failure in 9 children, cardiogenic shock in 8 children, and Adams-Stokes attack in 7 children. The median time from admission to implantation of temporary pacemakers was 3.0 h and the operation time was 55.0±19.4 min. All 4 children with epicardial pacing had pacemakers implanted during operation because of CAVB. The pacing mode was VVI mode. The initial perceptual voltage was 1-2 mv, the output voltage was 5v, and the pacing frequency was 70-145 bpm. A total of 11 children reverted to sinus rhythm within 5.0 (1.8-34.0) h and the working time of temporary pacemakers was 134.0 (15.0-191.0) h. There was poor pacing in 2 children and catheter displacement in 1 child during pacing. A total of 12 children were followed up for 20.0±12.5 months and 1 was lost to follow-up. During the follow-up period, the cardiac functions were basically normal and no new arrhythmia appeared.

CONCLUSIONS

Temporary pacemakers have the advantage of simple operation, definite effect, and safety which has a remarkable effect in the treatment of acute and critical cardiovascular diseases in children.