Dobutamine stress radionuclide ventriculography reveals silent myocardial dysfunction in Kawasaki disease

Area of Science:

• Cardiology
• Pediatric Cardiology
• Diagnostic Imaging

Background:

• Kawasaki disease (KD) can lead to coronary artery abnormalities and myocardial ischemia.
• Assessing long-term left ventricular (LV) performance in KD patients is crucial.
• Non-invasive methods are needed to evaluate LV function, especially diastolic parameters, in KD survivors.

Purpose of the Study:

• To evaluate the utility of Dobutamine (DOB) stress radionuclide ventriculography (RVG) for assessing LV performance in patients with a history of KD.
• To compare LV diastolic filling and relaxation patterns in KD patients with and without evidence of myocardial ischemia.

Main Methods:

• Dobutamine stress RVG was performed in 40 KD patients, categorized into groups based on prior dipyridamole stress thallium-201 imaging (perfusion defect, no perfusion defect, no coronary lesions).
• LV systolic and diastolic indices, including early diastolic filling and asynchrony, were analyzed at rest and during DOB stress.
• Hemodynamic responses and side-effects were monitored.

Main Results:

• No significant resting LV systolic or diastolic differences were found between groups.
• During DOB stress, early diastolic filling fraction significantly decreased only in patients with perfusion defects (PD group) compared to controls (p<0.01).
• The asynchrony index increased significantly in patients with coronary stenosis during DOB stress (p<0.05).

Conclusions:

• Dobutamine stress RVG is a safe and effective tool for evaluating LV performance in KD patients.
• The technique can identify impaired early diastolic filling and asynchronous relaxation in KD patients with myocardial ischemia, even years after the acute phase.
• DOB stress RVG serves as a promising alternative to exercise testing for serial assessment of LV function in KD survivors.