Article Text
Statistics from Altmetric.com
Acute myocardial infarction is the most serious complication of Kawasaki disease and is often fatal.1 ,2 We describe a case successfully treated by intracoronary thrombolysis.
Case report
A 13 month old boy with Kawasaki disease was found to have multiple coronary artery aneurysms 25 days after onset of illness. He was treated with aspirin and dipyridamole but four months later he presented with acute anterior myocardial infarction. Coronary angiography showed occlusion of the proximal left anterior descending artery (LAD), the distal vessel faintly opacifying through collaterals from the circumflex artery (fig 1A). Local infusion of urokinase into the left coronary artery (three doses of 5000 U/kg and one dose of 7000 U/kg) was initiated eight hours after the onset of symptoms. The LAD recanalised, but some thrombus remained in the aneurysm (fig1B). At that time myocardial contrast echocardiography showed contrast in the anterolateral wall of the left ventricle. Thereafter intravenous heparin was given for seven days followed by aspirin and warfarin. Two weeks later echocardiography showed normal ventricular wall motion and thallium scintigraphy showed only a mild anterior wall perfusion defect. Four months later repeat angiography showed the thrombus had completely resolved (fig 1C). The warfarin was stopped after a year and treatment was continued with aspirin and dipyridamole. Two years later the patient remained symptom free.
Left coronary artery angiograms (A) before thrombolysis, (B) after thrombolysis, and (C) four months later. (A) the occlusion is shown in the proximal portion of the LAD (arrow) and its peripheral segments are faintly visible through collateral arteries from the left circumflex artery (arrowheads). (B) After reperfusion thrombus (arrow) remained in the aneurysm. (C) The thrombus in the aneurysm has resolved with a decrease in size of the aneurysm.
Discussion
We chose to use intracoronary rather than peripherally administered urokinase because of the need for early and accurate assessment of thrombolysis. Myocardial contrast echocardiography appeared to predict myocardial viability3 as only a small area of ischaemia remained on thallium scan after reperfusion. This myocardial salvage is likely due to a combination of collateral circulation and early intervention with thrombolytic treatment. The complete resolution of thrombus after anticoagulation and antiplatelet agents in this case supports previous suggestions4 that this combination therapy may prevent progression of thrombosis within coronary artery aneurysms.