Cumulative Official WHO Updates to ICD 10 - 1996 - 2001

Heart failure (I50. ) and unspecified heart disease (I51.9) should be considered an obvious consequence of other heart conditions. ... subcategories at B20-B23 are the only optional four-character codes for countries using the four-character version of ICD-10. These four-character subcategories are provided for use where it is not possible or ... ................
................