| Abstract |
Background
Myocarditis is an inflammatory disease of the myocardium, mainly of viral etiology,
with a higher incidence in male infants and adolescents. Signs and symptoms of
myocarditis vary from mild to life-threatening. It is characterized by high levels of
troponin and and by specific findings on the electrocardiogram and echocardiogram.
Cardiovascular magnetic resonance imaging and endomyocardial biopsy are
considered diagnostic methods of choice. The prognosis of myocarditis is usually
good with a higher probability of complications in newborns and infants in the early
stages of the disease. Decreased left ventricular ejection fraction and high troponin
levels are considered to be the main poor prognostic factors.
Objective
The aim of this study is to record relevant epidemiological indicators of myocarditis
in the region of Crete and to associate demographic and clinical -laboratory data
with complications and disease outcome indicators. Also, a second purpose of the
study is to investigate the contemporary diagnostic methods of pediatric and
juvenile myocarditis and their contribution to the diagnosis and prognosis of the
disease.
Methods
This is a retrospective monocentric study, in which the sample included children,
adolescents and adults up to 32 years of age who were treated in the Pediatric
Intensive Care Unit (PICU) and the Cardiology Clinic of the University General
Hospital of Heraklion from 2008 to 2020 with the final diagnosis of myocarditis. Data
collection was done from electronic and printed patient files and included a variety
of variables for each patient. The statistical method included frequencies, descriptive
statistics, Pearson correlation, Chi-squared test, analysis of variance (ANOVA),
regressions and statistical analysis was performed with the SPSS program. Results
Eighty-seven percent of 76 patients were male with a mean age of 19 years and the
main symptom was chest pain with concomitant symptoms from the respiratory and
gastrointestinal systems. High levels of troponin were recorded, especially in PICU
patients and were statistically significant correlated with (p< 0.001) AST, LDH, CKMB,
but not with BNP and duration of hospitalization. The AST (p = 0.002) and CKMB
(p = 0.038) levels were independently related to the Tn-I levels of the day of
admission. Eighty-two percent of all patients had a pathological finding on the
electrocardiogram, with the most common being ST segment elevations and
negative T waves. ST segment elevation (65%) and negative T waves (59%) were
more common in PICU patients compared with patients in Cardiology Clinic (p =
0.015 and p = 0.025, respectively). Thirty-five percent of patients showed left
ventricular contractility disorder on ultrasound and the left ventricular ejection
fraction (LVEF) <40% was associated with increased white blood cells (WBC)(p
<0.001), decreased left ventricular wall mobility (p = 0.001) and negative disease
outcome. In seventy-five percent of patients who had a CMR, the test was positive
for myocarditis. Viral control showed that rhinovirus and enterovirus were the most
common causes of myocarditis. Younger patients hospitalized in PICU, were more
likely to have EF <40% compared with adults in the cardiology clinic (p = 0.01). A
negative outcome (deterioration or death) was better predicted by an EF <40% (p =
0.001) and an increased number of white blood cells (p = 0.002) on the day of
admission. More patients from the Cardiology Clinic improved compared to PICU
patients (98% vs. 79%, p = 0.012) and they showed a lower complication rate (3.6%
vs. 21.1%, p = 0.015).
Conclusion
Pediatric ICU patients have a more severe form of myocarditis than yound adult
patients of Cardiology Clinic, with higher troponin values and higher rates of reduced
contractility and left ventricular wall mobility disorder, ST segment elevations and
negative T waves. Rhinovirus and enterovirus are the most common viral causes of
myocarditis, and CMR is proved to be of high diagnostic value. Although acute myocarditis outcome is negatively affected by young age, initially increased number
of white blood cells and LVEF < 40%, its prognosis remains good in the majority of
patients.
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Μυοκαρδίτιδες στην παιδική και νεανική ηλικία : Επιδημιολογικά δεδομένα και προγνωστικοί δείκτες
