The decision included the following points:
"In the last decade several fundamental medical changes affecting heart
transplants have taken place:
a. The survival rate has risen. Approximately 80% of heart transplant recipients now survive at least one year(hayei olam, namely, long term life) and approximately 70% survive five years.
It is possible today to confirm in an absolutely reliable and secure manner that cessation of respiration in a dying person is final and irreversible.
Evidence has been brought before us that even Rabbi Moshe Feinstein , in later years, permitted heart transplant procedures in the United States [thereby reversing his previously negative position].
Based upon the Talmudic principles of Yoma 85, and ruled according to Hatam Sofer , the halakhah holds that death occurs with the cessation of respiration. Therefore one must confirm that respiration has ceased completely and irreversibly.
The medical-rabbinic committee must follow certain procedures and guidelines to confirm the brain death of the donor[which include the Harvard criteria and additional tests].*
Thus heart transplants were made possible from a religioushalakhic point of view as well as medically.
SHORT TERM VS. LONG TERM LIFE: HAYEI OLAM VE-HAYEI SHA'AH
A crucial halakhic issue is whether to endanger the short term life(hayei shaah, literally,"life of the hour") of the dangerously ill recipient of the organ transplant if this surgical action will increase his longevity(hayei olam, or long term life). At a time of certain danger, we do not pay attention to the short term as long as there is the slightest Chance of prolonging his life.