EDITORIALS Cardiac Shunts Newer Aids in Their Diagnosis

PRECISION IN CARDIAC DIAGNOSIS by labora-tory techniques has shown steady im-provement since World War II, an im-provement consequent to the introduction of cardiac catheterization, the many new electronic devices growing out of war-time developments, and the advent of corrective cardiac surgery. Available operative pro-cedures for correction of many of the con-genital defects of the heart and great vessels have led to especially intensive evaluation of these processes. Interest has been heightened not only in their earliest recognition, but in the determination of the anatomic site involved, the size of the defect, the amount and direction of bloo