Ventricular tachycardia in acute fulminant myocarditis: medical management and follow-up

Impact of ventricular arrhythmias on outcomes in children with myocarditis

Children affected with acute myocarditis may progress rapidly into profound ventricular dysfunction and ventricular arrhythmias. The objective of this study is to assess the impact of ventricular arrhythmias on in-hospital mortality and the use of mechanical circulatory support in patients with myocarditis. Pediatric patients (age 0-18 years) admitted with myocarditis were identified from the National Inpatient Sample dataset for the years 2002-2015. A total of 12,489 patients with myocarditis were identified. Of them, 1627 patients were with ventricular arrhythmias and 10,862 patients without ventricular arrhythmias. Mortality was higher in those with ventricular arrhythmias (19.5% vs. 2.8%, OR = 8.47; 95% CI 7.16-10.04; p < 0.001). The median length of stay and the median cost of hospitalization were higher in the ventricular arrhythmias group (9 days vs. 4 days, p < 0.001 and $121,826 vs. $37,658, p < 0.001, respectively). There was a substantial increase in the utilization of extracorporeal membrane oxygenation (ECMO) in patients with ventricular arrhythmias (25.4% vs. 2.7%, OR = 12.40; 95% CI 10.55-14.57; p < 0.001). The use of ventricular assist devices (VADs) was higher in patients with ventricular arrhythmias (4.5% vs. 1.3%, OR = 3.76; 95% CI 2.82-5.01; p < 0.001). An improvement in discharge survival was observed over the years of study in both VA and non-VA groups; associated with this decline in mortality, there was a rising trend of ECMO utilization.Conclusion: Development of ventricular arrhythmia in children with myocarditis is a strong predictor for mortality and ECMO utilization. What is Known: • The clinical presentation of pediatric myocarditis varies from no symptoms of myocardial dysfunction to a rapidly progressing severe congestive heart failure. • Little is known about the predictors of mortality in children with suspected myocarditis. What is New: • Development of ventricular arrhythmia in children with myocarditis is a strong predictor for mortality and ECMO utilization. • Improvement in discharge survival was observed over the years of study; associated with this decline in mortality, there was a rising trend of ECMO utilization.

Impact of Extracorporeal Membrane Oxygenation on Acute Fulminant Myocarditis-related Hemodynamic Compromise Arrhythmia in Children

BACKGROUND

Acute fulminant myocarditis (AFM) commonly presents as abrupt cardiogenic shock with or without dysrhythmia. This study evaluated the impact of extracorporeal membrane oxygenation (ECMO) on AFM-related hemodynamic compromise dysrhythmias. We also reported the clinical experience of AFM at our hospital.

METHODS

Eighteen children diagnosed with AFM were enrolled. Demographic variables, laboratory data, and clinical courses were reviewed. Thirteen surviving patients with hemodynamic compromise arrhythmia [complete atrioventricular block (CAVB) or ventricular tachycardia (VT)] during hospitalization were divided into Group A (ECMO group; n = 7) and Group B (non-ECMO group; n = 6).

RESULTS

The overall survival rate was 78% (14/18). There were no cases of mortality after ECMO was introduced at our hospital. Common symptoms at diagnosis included general malaise (94%), gastrointestinal symptoms (89%), chest pain (56%), shortness of breath (56%), and seizure/syncope (56%). In addition to abnormal cardiac enzyme levels, all patients displayed elevated alanine aminotransferase levels during early disease stages. Electrocardiography at diagnosis revealed dysrhythmia in 15 patients, namely, CAVB in 11 patients (61%) and VT in four patients (22%). During hospitalization, the dysrhythmia shifted from CAVB to VT in 10 patients and from sinus tachycardia to VT in one patient. New episodes of VT were common (overall occurrence rate, 83%). Although myocardial damage and dysfunction were more severe in Group A, the time to rhythm recovery in this group was shorter than that in Group B (median time, 1.7 days vs. 7.35 days, p = 0.045). All surviving patients had normal ventricular function at 6-month follow-up.

CONCLUSION

Hemodynamic compromise arrhythmia is common in AFM patients and may cause rapid deterioration. Simply correcting sinus rhythm is not always sufficient because of myocardium instability. Timely use of ECMO can improve the survival rate and shorten the time to recapture sinus rhythm in AFM patients with CAVB or VT.

In-hospital arrhythmia development and outcomes in pediatric patients with acute myocarditis

Cardiac arrhythmias are a complication of myocarditis. There are no large studies of in-hospital arrhythmia development and outcomes in pediatric patients with acute myocarditis. This was a retrospective 2-center review of patients ≤21 years hospitalized with acute myocarditis from 1996 to 2012. Fulminant myocarditis was defined as the need for inotropic support within 24 hours of presentation. Acute arrhythmias occurred at presentation and subacute after admission. Eighty-five patients (59% men) presented at a median age of 10 years (1 day to 18 years). Arrhythmias occurred in 38 patients (45%): 16 acute, 12 subacute, and 9 acute and subacute (1 onset unknown). Arrhythmias were associated with low voltages on the electrocardiogram (14 of 34, 41% vs 6 of 47, 13%; odds ratio [OR] 4.78, 95% confidence interval [CI] 1.60 to 14.31) and worse outcome (mechanical support, orthotopic heart transplant, or death; OR 7.59, 95% CI 2.61 to 22.07) but were not statistically significantly associated with a fulminant course, ST changes, initial myocardial function, lactate, creatinine level, C-reactive protein and/or erythrocyte sedimentation rate, or troponin I level, after adjusting for multiple comparisons. Subacute arrhythmias were associated with preceding ST changes (10 of 15, 67% vs 15 of 59, 25%, OR 5.87, 95% CI 1.73 to 19.93). All patients surviving to discharge had arrhythmia resolution or control before discharge (10 on antiarrhythmic), with 1 exception (patient with complete heart block requiring a pacemaker). At 1-year follow-up, there were 3 recurrences of ventricular arrhythmias, but no arrhythmia-related mortality. In conclusion, arrhythmias are common in pediatric patients with myocarditis, occurring in nearly 1/2 of all hospitalized children and are associated with a worse outcome. Early identification of subacute arrhythmias using electrocardiographic changes may help management. A majority of patients do not require continued postdischarge arrhythmia treatment.

The follow-up evaluation of electrocardiogram and arrhythmias in children with fulminant myocarditis

BACKGROUND

Fulminant myocarditis involves various serious arrhythmias that sometimes have lethal consequences. The purpose of the present study was to investigate the electrocardiogram findings, arrhythmogenicity and abnormalities of the cardiac conduction system in children with fulminant myocarditis.

METHODS AND RESULTS

Between 1999 and 2008, 7 consecutive patients (mean age: 7 years) who suffered from fulminant myocarditis were included in the study. A 12-lead electrocardiogram, Holter monitoring and signal-averaged electrocardiograms were performed and compared between the acute, convalescent, and recovery phases in the 4 surviving patients. Also, electrophysiologic assessment was carried out during the convalescent phase. Five out of 7 patients developed complete atrioventricular block, 3 developed ventricular tachycardia, 2 had cardiac arrest, 2 developed sinus tachycardia, 1 developed ventricular fibrillation, 1 had advanced atrioventricular block, and 1 developed sick sinus syndrome. Among the surviving patients, all arrhythmias resolved during the convalescent and remote phases. No atrial or ventricular arrhythmias were induced in any patients during the programmed stimulation study. In the convalescent phase, no arrhythmias could be induced and there were no signs of any conduction abnormalities on electrophysiological assessment.

CONCLUSIONS

Close follow-up should be performed to observe for the occurrence of any new arrhythmias and/or a decrease in cardiac function in children with fulminant myocarditis.

Amiodarone for the emergency care of children

Amiodarone is a class 3 antiarrhythmic agent used for a broad range of arrhythmias including adenosine-resistant supraventricular tachycardia, junctional ectopic tachycardia, and ventricular tachycardia. Compared with adults, there are few data on its use in children with arrhythmias resistant to conventional therapy. National and international guidelines for cardiopulmonary resuscitation and emergency cardiovascular care recommend its use for a variety of arrhythmias based on case reports, cohort studies, and extrapolation from adult data. This article will review the historical development, chemical properties, metabolism, indications and contraindications, and adverse effects of amiodarone in infants and children. After completing this CME activity, the reader should be able to utilize amiodarone in the pediatric population for arrhythmias and identify complications associated with its use.