What is the management approach for dengue myocarditis?

Management of Dengue Myocarditis

Hospitalize all patients with confirmed or suspected dengue myocarditis at an advanced heart failure center, with immediate transfer to a center with mechanical circulatory support capabilities if fulminant presentation develops. 1

Initial Diagnostic Evaluation

When dengue myocarditis is suspected based on chest pain, dyspnea, arrhythmias, or hypotension, perform the following immediately:

• ECG to detect ST-segment changes, conduction abnormalities, QTc prolongation, or QRS widening 1, 2
• Cardiac troponin I (preferred over troponin T as it is more specific when viral illness is present) 1
• Transthoracic echocardiogram to assess left ventricular systolic function, wall motion abnormalities, and pericardial involvement 1, 2
• BNP measurement (levels >500 pg/ml indicate significant concern) 3
• Cardiac MRI in hemodynamically stable patients to confirm myocardial inflammation using T1/T2 mapping and late gadolinium enhancement 1, 2

Risk Stratification and Hospitalization Criteria

Mandatory hospitalization is required for: 1, 2

• Elevated or rising cardiac troponin levels
• New ECG abnormalities (ST changes, conduction blocks, arrhythmias)
• Any degree of left ventricular systolic dysfunction on echocardiography
• Symptomatic bradycardia or tachyarrhythmias
• Hemodynamic instability or signs of cardiogenic shock

Transfer to advanced heart failure center with mechanical support capabilities if: 1

• Cardiogenic shock develops
• Sustained ventricular arrhythmias occur
• Advanced AV block is present
• Progressive hemodynamic deterioration despite initial management

Fluid Management Strategy

Critical principle: Both inadequate and excessive fluid administration worsen outcomes in dengue myocarditis. 1

• Administer initial fluid bolus of 20 mL/kg for dengue shock syndrome 1
• Reassess frequently after each fluid bolus to detect early deterioration 1
• Avoid aggressive fluid resuscitation in patients with myocardial dysfunction, as this can precipitate pulmonary edema 4, 5
• Monitor for signs of fluid overload (pulmonary edema, worsening dyspnea) given the combination of capillary leak syndrome and myocardial impairment 4

Pharmacological Management

Anti-inflammatory Therapy

For pericardial involvement or persistent chest pain: 1

• NSAIDs as first-line for pericardial inflammation (avoid in severe thrombocytopenia)
• Low-dose colchicine or prednisone for persistent symptoms
• Taper based on clinical response and symptom resolution

For hemodynamic compromise or severe myocarditis: 1

• Intravenous corticosteroids (methylprednisolone 1 mg/kg IV) should be considered in patients with:
  • Hemodynamic instability
  • Acute heart failure or cardiogenic shock
  • Severe myocardial dysfunction on imaging

Heart Failure Management

Initiate guideline-directed medical therapy cautiously: 1

• Low-dose aldosterone antagonists empirically in patients with mildly reduced LVEF and stable hemodynamics
• Beta-blockers may help with supraventricular arrhythmias if hemodynamically stable, but can precipitate cardiogenic shock in compromised patients—use with extreme caution 1
• ACE inhibitors/ARBs should be initiated before discharge and titrated in outpatient setting 1

Arrhythmia Management

For symptomatic bradycardia or high-grade AV block: 2

• Temporary pacemaker insertion is recommended for symptomatic conduction disease 2, 6
• Permanent pacemaker indicated if conduction abnormalities persist beyond acute phase 2

For ventricular arrhythmias: 2

• Continuous telemetry monitoring is mandatory
• Standard ACLS protocols for sustained ventricular tachycardia/fibrillation
• Consider temporary pacing if VT/VF triggered by high-grade AV block 2

Mechanical Circulatory Support

For fulminant myocarditis with cardiogenic shock: 2

• Percutaneous cardiopulmonary support or intra-aortic balloon pump in addition to pharmacological therapy
• Initiate mechanical support if VT/VF is refractory to 3-5 defibrillation attempts 2
• Early consultation with advanced heart failure team is critical, as short-term survival in fulminant myocarditis is only 58% 2

Activity Restriction

Avoid all strenuous physical activity for 3-6 months after diagnosis of dengue myocarditis 1, 7

• This restriction applies even if symptoms resolve quickly
• Return to activity should be based on: resolution of symptoms, normalization of cardiac biomarkers, normal LVEF, and absence of arrhythmias on ambulatory monitoring 7

Follow-up Protocol

Structured follow-up at 3-6 months post-discharge: 1

• Repeat ECG
• Repeat echocardiogram to assess for recovery of ventricular function
• Ambulatory rhythm monitor (Holter or event monitor)
• Consider repeat cardiac MRI if initial imaging showed significant inflammation
• Monitor for development of dilated cardiomyopathy (occurs in 21% of myocarditis patients long-term) 2

Critical Clinical Pearls

High index of suspicion is essential: 5, 8

• Dengue myocarditis often masquerades as acute coronary syndrome with ST-segment depression and elevated troponin 6, 5
• Cardiac complications occur in 11.28% of hospitalized dengue patients, with higher prevalence (46.66%) in severe dengue 9
• Most cases are self-limited, but fatal outcomes have been reported 5, 8
• Myocarditis patients experience longer hospital stays (7.17 vs 5.98 days) but generally have good prognosis with appropriate management 9

Warning signs requiring immediate escalation: 1, 9

• Supraventricular tachycardia (14.29% in severe dengue with myocarditis)
• Atrial fibrillation (25.71% in severe dengue with myocarditis)
• Progressive hypotension despite fluid resuscitation
• Development of pulmonary edema
• Persistent or worsening troponin elevation

Common pitfall: Normal cardiac enzymes cannot rule out myocarditis—comprehensive cardiac evaluation is essential even when initial biomarkers appear reassuring. 3