Muscular and cardiac pathologies new
October 17, 2026Muscle pathology – Patient unstable
October 17, 2026Myocarditis algorithm
ICI + troponin elevation
Step 1 - Baseline work-up
Investigations
- Repeat troponin to assess dynamics
- Troponin I, if available
- CK, LDH, ALT and NT-proBNP
- 12-lead ECG and urgent TTE
Screen for overlap syndrome
- Myalgia / proximal muscle weakness
- Dysphagia, ptosis, diplopia
- Dysarthria / respiratory weakness
Exclude alternatives Troponin elevation
- Acute MI, pulmonary embolism
- Arrhythmia or severe HF
- Renal failure or drug myotoxicity
- etc
Step 2 - Biological interpretation
Troponin I elevated
Active myocardial injury likely
Troponin T + CK elevated Troponin I not elevated
Skeletal-muscle injury likely
(refer to myopathy algorithm)
Troponin T elevated Troponin I unavailable
Consider myocardial OR
skeletal-muscle injury
Troponin I is more specific of cardiac involvement than Troponin T which can rise in myopathy
Step 3 - Severity and diagnostic pathway
Consider submitting the case to BITOX for diagnostic and management guidance and to support access to non-reimbursed medication
Is the patient unstable?
- Haemodynamic instability
- Heart failure requiring ventilatory support
- New high-grade block
- New sustained ventricular arrhytmia
YES, Patient is unstable
Suspected fulminant myocarditis
NO, Patient is stable
Assess severity +
IC-OS diagnostic criteria for myocarditis