Pakistani President Asif Ali Zardari has traveled to Dubai for medical reasons, fueling speculation in Pakistan that the embattled leader may resign.

The president was undergoing routine tests related to a previously diagnosed heart condition, according to his spokeswoman, Farahnaz Ispahani.

His trip sparked rumors that he has suffered a heart attack, but a spokesman for Prime Minister Yousuf Raza Gilani, Farhatullah Babar, described those reports as "speculative, imaginary and untrue."

The president went to Dubai "at the insistence" of his children, the prime minister said.