Patriarch Elias IV, 65, the spiritual leader of Antiochian Orthodox Christians, died of a heart attack Thursday in Damascus, Syria.

The white-haired prelate, whose predecessors had crowned the Russian Romanov czars, held the same position for his followers that the pope does for Roman Catholics.

The patriarch was considered the successor of St. Peter and St. Paul. His ancient headquarters were in Antioch, Syria. It is one of five ancient seas of Christiandom. The others are Alexandria, Constantinople, Jerusalem and Rome. There are an estimated 6 million to 8 million Orthodox Christians worldwide.

The Lebanese-born churchman was an outspoken supporter of the Palestinian right to a homeland. He termed his followers in the Antiochian Orthdox Chruch "Christian Arabs." He actively made common cause with Muslem and Rome. There are an estidarity."

Patriarch Elias reiterated his support for a Palestinian homeland in 1977 when he visited this country. He was the first f 164 Antichian patriarchs since the time of Christ to visit the United States.

He met with President Carter in July 1977 and told reporters then that he had "urged the president to bring peace in the Middle East." This, he added, would require a solution to the Palestinian homeland problem.

Later that month, he addressed a convention in Washington of North American Antichian Orthtdox Christians. He spoke then of his efforts in this country and throughout the Orthodox world to bring about pan-Orthodox unity, which he said was "inevitable."

The 12 bishops of the Antioch See will hold a conclave after his funeral to elect a new patriarch.