(1) In Tokyo metropolitan area, CCU network including 17 hospitals has been established. Its aim is saving the lives of patients with acute myocardial infarction by facilitating their admission to CCU as promptly as possible. The task of hospitals cooperating in the CCU network is 1) to admit without fail patients suspected of myocardial infarction, 2) to transmit ECG by telephone lines and 3) to perform telephonic consultation. ECG telephone line transmission is a system in which an ambulance having equipment to transmit a patient's ECG on a telephone line goes to the actual site where the patient is located and transmits the patient's ECG on an ordinary telephone line to the CCU staff installed in the CCU if myocardial infarction is suspected. The CCU staff interprets the transmitted ECG and advises the ambulance staff on what action should be taken. If an emergency does not permit such time to be taken, only telephone consultation without transmission of standard 12-1ead ECG will be used by the ambulance staff. By this method, about 10 minutes of time can be saved as compared with ECG telephone line transmission, and the objective achieved within a shorter period. (2) In 19 cases of cardiogenic shock due to acute myocardial infarction, the clinical results obtained by intra-aortic balloon pumping (IABP) alone and in combination with the use of isosorbide dinitrate (ISDN), and the therapeutic results have been discussed. At 48 hours after the start of IABP, the maximal effect could be obtained with significant decrease in heart rate, pulmonary capillary wedge pressure (PCWP), central venous pressure and systemic vascular resistance and significant increase in systolic and diastolic blood pressure, cardiac index (CI), stroke volume index and transmyocardial pressure gradient. A comparison of the left ventricular function curves of survivors (6 cases) and non-survivors ( 13 cases) revealed that in the former group the curve shifted toward the upper left area, commencing at 12 hours after the start of IABP and continuing up until after completion of IABP, while in the latter group the curve shifted toward the right upper area from 48 to 60 hours after the start of IABP, followed by a shift toward the lower right area thereafter, with a more aggravating tendency after completion of IABP. When IABP was combined with ISDN, a remarkable improvement could be obtained in cardiac function 15 minutes after sublingual administration of ISDN. Among 19 cases in which IABP was applied, this treatment could be successfully discontinued in 13 cases (68%), with 6 of them surviving for prolonged periods of more than 6 months. It is concluded that IABP is effective in improving the hemodynamics of cardiogenic shock due to acute myocardial infarction. Maximum response is noted between 24 and 48 hours.