Doctors attending to the Crown Prince said that the heart attack was caused by blood circulation problems to the lower portion of his heart.
Dr Bharat Rawat, who led a team of 12 doctors, said "balloon angioplasty" was conducted successfully.
The operation took 50 minutes, he said.
"The Crown Prince will be kept at the intensive care unit for two days and will be shifted to general ward thereafter. Now, his condition is much better," the BBC quoted Dr Rawat, as saying.
The 36-year-old Crown Prince is known for his wild lifestyle. He was rushed to the military hospital after he complained of chest pain.
Later, the military hospital transferred him to the private Norvic Hospital.
Doctors say the prince would "need to change his diet and lifestyle".
Crown Prince Paras is the only son of King Gyanendra and has been at the centre of many scandals.