Former Chief Sephardi Rabbi Mordechai Eliyahu was improving Sunday after suffering a heart attack on Shabbat and undergoing open-heart surgery at Jerusalem's Shaare Zedek Medical Center. The 80-year-old rabbi was rushed by ambulance to the hospital after complaining of chest pains and weakness. He is due to be moved from the intensive care unit to the cardiology department soon. His operation was performed by a large team headed by cardiac surgery chief Dr. Dani Bitran. Eliyahu's son, Shmuel, who is chief rabbi of Safed, called on the public to pray for the speedy recovery of his father. In accordance with Jewish custom, the former chief rabbi's full name - Mordechai Tzemach - was publicized, as was the name of Mordechai's mother, Mazal Tov. Shmuel Eliyahu also requested that the entire Book of Psalms be repeated 1,000 times by synagogue goers across the nation. In addition, prayer groups all over Israel recited psalms at the end of daily prayers, which are believed to arouse God's sympathy. Between 1983 and 1993 Eliyahu served as chief sephardi rabbi of Israel together with former chief Ashkenazi rabbi Avraham Shapira, who passed away in September. During and after their stint as chief rabbis, the two men were considered the senior halachic authorities of religious Zionism. However, since the religious Zionist community - as opposed to haredi Jewry - is much less centrally controlled by rabbinic authority, there has been much dissent against Shapira's and Eliyahu's opinions over the years. The most controversial issue which has split religious Zionism in recent years has been the response to the 2005 disengagement from the Gaza Strip. Both Eliyahu and Shapira called on IDF soldiers to refuse orders rather than take part in the evacuation of Jewish communities from Gaza. Eliyahu was also widely criticized for claiming on the eve the disengagement that God would not let it happen. Eliyahu's most recent ruling was a call to refrain from buying produce grown by non-Jews during the shmita year. Eliyahu said it was preferable to rely on a controversial halachic innovation known as heter mechira ("permitted sale") rather than buy from non-Jews, mostly Arabs, who - said Eliyahu - are the Jewish people's enemies. Eliyahu's ruling is diametrically opposed to the haredi halachic stance, which dictates buying produce grown on land owned and worked by non-Jews.