phase 4, (in cardiology) the period of electrical diastole. A graph of phase 4 shows a gradual upward slope in a pacemaker cell, whereas phase 4 in a nonpacemaker cell is flat.
phase 4, (in cardiology) the period of electrical diastole. A graph of phase 4 shows a gradual upward slope in a pacemaker cell, whereas phase 4 in a nonpacemaker cell is flat.