Abstract: An apparatus for diastolic blood retroperfusion of the coronary sinus in synchronism with the heartbeat rate for the treatment of infarctions. A connecting tube between an artery and the coronary sinus is fitted with a balloon-type catheter. A pulsatile unit mounted on the tube is controlled by an electrovalve in dependence on an electronic console and in synchronism with the patient's electrocardiogram (ECG) in order to retroperfuse arterial blood in the coronary sinus during diastoles and to permit the return flow of vitiated blood to the lungs during systoles. The apparatus permits diastolic retroperfusion of arterial blood in synchronism with the patient's electrocardiogram with maximum safety.