Acute Myocarditis and Management in children.pptx

acute myocarditis in children

1. Myocarditis In Children Dr. Mohammad Al Ktifan AWH- Pediatric Emergency 

2. INTRODUCTION Definition : Myocarditis is an inflammatory disease of the myocardium with many different etiologies, most of which are infectious . Affected patients can present with a broad clinical spectrum of signs and symptoms ranging from subclinical disease to cardiogenic shock, arrhythmias, and sudden death.

3. INCIDENCE Myocarditis is rare in children, 1–2 per 100,000 children/year .  The estimated prevalence of myocarditis among children presenting to their emergency department was 0.5 cases per 10,000 visits . In autopsy studies, evidence of myocarditis is noted in 10 to 20 % of infants and children who died suddenly and unexpectedly 

4. ETIOLOGY The causes of myocarditis are diverse and include infectious, toxic, and autoimmune etiologies . Infectious, particularly viral, etiologies are most common in children. -Rarely, pediatric myocarditis may be associated with autoimmune disorders and drug hypersensitivity.

5. Causes of myocarditis Infectious causes: - Viral (most common): Enteroviruses (e.g., Coxsackie B virus) Adenovirus Parvovirus B19 human herpes 6 , CMV, EBV Influenza A, B COVID-19 (SARS-CoV-2)

6. Bacterial : Brucellosis , Chlamydia , Diphtheria, Mycoplasma, Pneumococcal , Staphylococcal , Streptococcal, Tetanus Protozoal : Leishmaniasis – Malaria –Toxoplasmosis Spirochetal : Leptospirosis - Lyme disease- Syphilis

7. Noninfectious Causes Cardiotoxins : Alcohol , Carbon monoxide, Catecholamines , Cocaine Cyclophosphamide, Heavy metals (copper, lead, iron) Systemic disorders: Celiac disease, SLE , Inflammatory bowel disease (Crohn disease, ulcerative colitis) , Kawasaki disease Post-vaccine (rare): mRNA COVID-19 vaccines in adolescents

8. Pathophysiology Three Phases: Acute Viral Phase : Direct viral invasion → myocyte necrosis Immune Activation Phase : Cytokines, antibodies, T-cells → further myocardial damage Recovery vs Chronic Damage : Resolution OR persistent inflammation → dilated cardiomyopathy

9. CLINICAL MANIFESTATIONS Presentation :  The clinical presentation of myocarditis is variable. Affected patients can present with a broad clinical spectrum of signs and symptoms ranging from subclinical disease to cardiogenic shock, arrhythmias, and sudden death 

10. Presentation : Viral prodrome: -  Because the most common etiology of pediatric myocarditis is viral, patients often have a history of a recent respiratory or, less commonly, gastrointestinal illness within the previous two weeks. -  Patients typically have a prodrome of fever, myalgia, and malaise several days prior to the onset of symptoms of heart dysfunction.

11. Nonspecific symptoms : Nonspecific signs and symptoms such as respiratory distress or gastrointestinal symptoms (anorexia, abdominal pain, and vomiting) may be the most prominent features at presentation. These nonspecific symptoms are often more suggestive of other diagnoses ( eg , respiratory tract infection, gastroenteritis, appendicitis), leading to an incorrect initial diagnosis in many children 

12. Heart failure symptoms  : Infants and children usually have signs and symptoms of heart failure at presentation. This may include:  dyspnea at rest  exercise intolerance  syncope  Tachypnea persistent tachycardia  hepatomegaly

13. Arrhythmias  : Supraventricular and ventricular arrhythmias and complete heart block may be present . In a case series of pediatric patients hospitalized at two centers, arrhythmias occurred in 45 % either at presentation or during hospitalization Arrhythmias may contribute to cases that present as unexpected death, presumably due to ventricular arrhythmia

14. Fulminant myocarditis: A subset of patients have fulminant myocarditis and present with an acute onset of severe hemodynamic compromise . These critically ill children present with signs of decreased cardiac output, including hypotension, weak pulses, poor perfusion, acidosis, and hepatomegaly, which may progress to cardiovascular collapse.  Malignant arrhythmias are also commonly seen. In some cases, the clinical course progresses so rapidly that it is challenging to make the diagnosis and provide appropriate therapy before progression to severe cardiogenic shock and death .

15. In a report of 171 pediatric patients with myocarditis seen at a single institution, the following signs and symptoms were noted : - Chest pain ( 45% ) - Respiratory distress ( 28 %) - Gastrointestinal symptoms ( 27% ) - Hepatomegaly ( 27% ) - Gallop rhythm ( 20% ) - Poor perfusion/diminished extremity pulses ( 16% ) - Viral prodrome ( 41% )

16. Physical examination     In symptomatic patients, the physical examination often reveals direct evidence of cardiac dysfunction , although these findings are  not  specific to myocarditis: Respiratory findings include tachypnea, retractions, and rales. Third heart sound (S3 ) and fourth heart sound ( S4) gallops may be present and are important signs of impaired ventricular function, particularly when biventricular acute myocardial involvement results in systemic and pulmonary congestion . - If the right or left ventricular dilation is severe, auscultation may reveal murmurs of functional mitral or tricuspid insufficiency

17. In acute fulminant myocarditis, signs of low cardiac output and shock may be present, including hypotension, poor pulses and perfusion, edema, hepatomegaly, and altered mental status. A pericardial friction rub and effusion may become evident in some patients with myopericarditis

18. INITIAL EVALUATION Initial testing generally is focused on determining the presence and severity of cardiac dysfunction and includes : Electrocardiography (ECG) Cardiac biomarkers (troponin) Brain natriuretic peptide (BNP) or N-terminal- proBNP (NT- proBNP ) Chest radiography Echocardiography

19. Electrocardiogram   The ECG in myocarditis is usually abnormal, although changes are neither specific nor sensitive. Changes include : ST-segment and T wave abnormalities ( eg , inverted T waves), abnormal axis, ventricular or atrial enlargement, and decreased voltage. The rhythm is most commonly sinus tachycardia; however, ventricular premature beats, atrial premature beats, supraventricular tachycardia, and ventricular tachycardia may be seen . Complete heart block occurs less often 

20. Sinus tachycardia with non-specific ST segment changes

21. Widespread concave ST elevation ( pericarditic  changes) in a child with viral myocarditis

22. Cardiac biomarkers (troponin) Elevated levels of cardiac biomarkers ( eg , cardiac troponin I and troponin T) reflect myocardial injury. Elevated troponin is seen in most, but not all, patients with myocarditis . However, this is a nonspecific finding and should be interpreted in conjunction with other clinical and echocardiographic findings.  Although elevated levels of troponin I and troponin T are seen in the majority of patients with myocarditis, the degree of elevation does not correlate with disease severity.

23. In one multicenter review of pediatric patients presenting with myocarditis, patients with mild ventricular dysfunction had significantly higher levels of troponin I than those with moderate or severe ventricular dysfunction . An elevated troponin level can help distinguish acute myocarditis from chronic dilated cardiomyopathy that troponin T levels were higher in patients with myocarditis compared with those with dilated cardiomyopathy.   In addition, a small percentage of pediatric patients with myocarditis may have normal troponin levels.   As a result, elevation of cardiac biomarkers is a nonspecific finding of myocarditis in children.

24. Natriuretic peptides   -   BNP and NT- proBNP concentrations may be elevated in myocarditis and may help distinguish between respiratory symptoms related to heart failure and those related to primary pulmonary pathology . In a small series of 19 patients with parvovirus B19 myocarditis, BNP levels were elevated in all 12 patients who were tested, ranging from 348 to >8000 pg /mL

25. Chest radiograph   Chest radiography may be abnormal in approximately one-half of the cases of myocarditis. Findings are nonspecific and include : Cardiomegaly pulmonary vascular congestion less commonly, pleural effusions

26. Anterior-posterior chest radiograph of an adolescent with viral myocarditis.  The child was a previously healthy 15-year-old boy who presented with severe chest pain in the setting of a viral prodrome. Chest radiograph demonstrates mild cardiomegaly, bilateral pleural effusions, prominence of the central pulmonary vessels, and interstitial haziness, suggestive of pulmonary edema .

27. Anterior-posterior chest radiograph of a child with fulminant viral myocarditis. The child was a previously healthy 9-year-old girl who presented with progressive orthopnea, cough, and respiratory distress following 2 weeks of a viral prodrome. Chest radiograph demonstrates bilateral lung opacities, sizable bilateral pleural effusions, and borderline cardiomegaly. The child presented in severe distress and suffered cardiopulmonary arrest shortly after arrival to the emergency department. Management included inotropic support, diuretic therapy, placement of bilateral chest tubes, and intravenous immune globulin. She subsequently made a full recovery.

28. Echocardiogram The echocardiogram typically shows impaired left ventricular function . The systolic dysfunction is generally global, but regional or segmental abnormalities may also be seen. Changes in left ventricular geometry , wall motion abnormalities, Pericardial effusion,  and mitral regurgitation may also be seen. The echocardiogram also rules out noninflammatory cardiac diseases such as anomalous left coronary artery from the pulmonary artery (ALCAPA), which may have a similar presentation.

29. Cardiac MRI (Gold standard non-invasive): - It is considered a noninvasive test, infants, small children, and those who are severely affected still require intubation and mechanical ventilation to facilitate required breath-holding sequences and reduce motion to improve imaging quality. These risks must be considered in patients who have significant ventricular dysfunction with minimal hemodynamic reserve . Myocardial edema Late gadolinium enhancement (LGE) – indicates fibrosis/inflammation

30. Figure 2.  A 15-year-old boy with Epstein–Barr virus myocarditis: ( a ) a short-axis T2-weighted image demonstrating focal myocardial oedema (red arrows); and ( b ) a short-axis T1-weighted late gadolinium enhancement image (red arrows). RV, right ventricle; LV, left ventricle.

31. Endomyocardial Biopsy (EMB) EMB is considered the gold standard for the diagnosis of myocarditis - EMB has a low sensitivity, and it requires invasive cardiac catheterization, which carries risks, particularly in small children and those who are critically ill. The histopathologic diagnosis of myocarditis has historically been made by standard light microscopy according to the Dallas criteria; however, this approach is limited by poor sensitivity. EMB is suggested in selected children with fulminant or acute, unexplained heart failure.

32. Other Studies  : Additional laboratory tests that are often performed in children who present with signs and symptoms of cardiovascular dysfunction include the following: Markers of inflammation : ESR and CRP are frequently elevated in myocarditis, but these are nonspecific findings and not useful in establishing a diagnosis CBC may show evidence of infection, but this is a nonspecific finding

33. Blood gases may demonstrate a metabolic acidosis in children with acute fulminant myocarditis resulting in inadequate systemic perfusion. For patients who have signs and symptoms of associated systemic disease, additional testing for autoimmune or inflammatory conditions may be appropriate ( eg , SLE )

34. Differential Diagnosis - Sepsis - Dilated cardiomyopathy - Kawasaki disease - Congenital heart disease - Toxic ingestion - Pericarditis - Coronavirus disease 2019 (COVID-19)-related multisystem inflammatory syndrome in children (MIS-C)  - Arrhythmias (primary conduction disorders)

35. Management In the acute phase of viral myocarditis, the patient should be admitted to the hospital, even if only mild signs of respiratory distress or congestive heart failure are present.  Rapid progression to overt heart failure, hemodynamic collapse, or both may occur: Early recognition and rapid management is crucial. Consultation with a cardiologist is indicated. Transfer to a facility with intensive and cardiology care may be required.  No specific proven therapy is available to prevent myocardial damage, but maintenance of tissue perfusion is the goal to avoid further complications.

36. ACUTE MANAGEMENT Because of the high risk of arrhythmias and hemodynamic compromise during the acute inflammatory phase of the disease, children with myocarditis who present with severely depressed ventricular function or rhythm disturbances should be cared for in a pediatric intensive care unit. All patients require ongoing cardiorespiratory monitoring as the hemodynamic status of the patient may quickly deteriorate even if cardiac function is initially intact .

37. Hemodynamic support   At presentation, infants and children with myocarditis usually have signs and symptoms of heart failure. Supportive care interventions depend upon the degree of symptoms: - Initial supportive treatment consists of supplemental oxygen and careful fluid resuscitation. - Children with mild symptoms can generally be managed with oral diuretics and afterload-reducing agents ( eg , ACE inhibitors). - Children with more severe symptoms ( ie , decompensated heart failure or cardiogenic shock) may require intravenous inotropic support, mechanical ventilation, and even mechanical circulatory support.

38. Medical therapy for heart failure: - In patients who are asymptomatic or mildly symptomatic with evidence of depressed ventricular function, medical management with oral therapy generally includes: - Diuretics - Afterload-reducing agents (eg, angiotensin-converting enzyme inhibitors)

39. Decompensated heart failure/cardiogenic shock     Severely affected patients are at risk for circulatory collapse. Medical intervention for these patients includes: Intensive management of heart failure  : This includes intravenous diuretics and inotropic agents, such as  milrinone . dopamine , and  dobutamine . Positive pressure ventilation:   can improve cardiac function by reducing work of breathing, reducing left ventricular afterload, and increasing systemic oxygen levels. Mechanical support : Infants and children with severe circulatory compromise despite medical management may need temporary mechanical circulatory support using ECMO or VAD .

40. Arrhythmia Management: Antiarrhythmic agents if needed Temporary pacing for heart block Defibrillation for VT/VF Immunomodulatory Therapy: IVIG : Some evidence for benefit, especially early Steroids : Controversial, may be used in biopsy-proven immune-mediated myocarditis

41. Cardiac Transplant: If refractory to medical therapy and not improving with mechanical support 5 to 20% of children with acute myocarditis require heart transplantation

42. Morbidity and Mortality   Reported mortality rates during the acute illness for children with myocarditis range from 6 -14% Late deaths are uncommon, occurring in <5 % of patients. Most late deaths are due to persistent ventricular dysfunction, heart failure, or complications following heart transplantation .

43. In a study investigating predictors of mortality in pediatric patients with myocarditis, 50 % of those patients who died had cardiac arrest within three hours of hospital admission , Because it is difficult to distinguish fulminant myocarditis from other types of shock initially, such patients are usually treated broadly (including empiric treatment for septic shock).

44. conclusion Pediatric myocarditis is a rare but serious condition with a broad spectrum of clinical presentations, from mild symptoms to life-threatening cardiac dysfunction. Early recognition and diagnosis are crucial, especially in children presenting with unexplained tachycardia, chest pain, or signs of heart failure following a viral illness. Always consider myocarditis in children with viral prodrome and new-onset cardiac symptoms Timely diagnosis and management is the key to improve patient outcomes.