(a) When living will may be revoked. -- A living will may be revoked at any time and in any manner by the principal regardless of the mental or physical condition of the principal.

(b) Effect of revocation. -- A revocation is effective upon communication to the attending physician or other health care provider by the principal or a witness to the revocation.

(c) Medical record. -- The attending physician or other health care provider shall make the revocation part of the medical record of the principal.