Abstract: Objective To observe dynamic echocardiographic changes in patients with acute fulminant myocarditis and assess the clinical value of echocardiography in treatment with percutaneous cardiopulmonary support (PCPS). Method PCPS through the femoral artery/vein was used in the treatment of a patient with acute fulminant myocarditis, with dynamic echocardiographic observation of the atrial and ventricular volumes, left ventricular wall thickness, pulsatile amplitude and cardiac functions before and after PCPS. The position of the catheter of PCPS was also under dynamic bedside monitoring. Results and Conclusion The patient showed significant echocardiographic changes, such as weakening of the wall movement, lowered ejection fraction, widening of the left ventricular internal diameter with mild pericardial exudation. After PCPS, the cardiac functions such as the heart movement, ejection fraction and the shortening rate of the short axis were greatly improved as observed with ambulatory echocardiography. This case suggests that ambulatory echocardiography can be instrumental in the management of cardiac emergencies.