Clinical Scorecard: Electrocardiogram Alterations and Their Significance in Adult Vietnamese Individuals with Mild Dengue Infection

At a Glance

Key Highlights

• Cardiac manifestations in dengue range from <10% to 60% in hospitalized patients, including myocarditis and arrhythmias.
• ECG abnormalities in dengue are broad, nonspecific, often transient, and more frequent with increasing disease severity.
• In non-severe dengue, routine ECGs have limited utility for detecting cardiac complications, especially in resource-limited settings.

Guideline-Based Recommendations

Diagnosis

• Confirm dengue infection via PCR, NS1 antigen, or serology (IgM/IgG seroconversion or titre rise).
• Use 12-lead ECG to assess cardiac involvement, focusing on rate, rhythm, conduction intervals, and wave morphology.
• Apply standard ECG criteria: PR interval 120–200 ms, QRS 70–110 ms, QTc prolongation ≥450 ms (males) or ≥460 ms (females).

Management

• Monitor patients clinically for signs of severe dengue including shock and organ dysfunction.
• Supportive care remains primary; no specific cardiac treatment indicated solely based on ECG abnormalities in mild dengue.
• Avoid unnecessary ECGs in non-severe dengue unless clinical suspicion of cardiac involvement arises.

Monitoring & Follow-up

• Perform ECGs on admission, discharge, and follow-up (2–4 weeks) to observe transient changes.
• Monitor cardiac biomarkers (CKmb, troponins) if myocarditis suspected.
• Track clinical parameters including blood pressure, heart rate, and laboratory markers for disease progression.

Risks

• Potential progression to severe dengue with myocarditis, shock, or organ dysfunction.
• ECG abnormalities may not correlate with echocardiographic findings; clinical correlation is essential.
• QTc prolongation and arrhythmias may occur but are generally transient and resolve over time.

Patient & Prescribing Data

Adult Vietnamese patients with confirmed non-severe dengue infection

Prior to admission, some patients received vitamins, paracetamol, and antibiotics; no specific cardiac therapies were indicated based on ECG findings.

Clinical Best Practices

• Use Fridericia correction formula for QT interval to minimize heart rate dependency in dengue patients.
• Interpret T wave inversion only if present in two or more specified leads to avoid normal variants.
• Reserve ECG use for patients with clinical signs suggestive of cardiac involvement or severe dengue.
• Consider serial ECG monitoring to detect transient conduction abnormalities or arrhythmias.
• Integrate ECG findings with clinical and laboratory data for comprehensive patient assessment.

References

• WHO Dengue Guidelines 2009
• American Heart Association Recommendations on QTc Prolongation