The "sleepless nights and gruelling schedule" of the election campaign and impending presidency could prove a deadly cocktail for the 70-year-old, Dr Patrick Heck said.
The shock claims are in contradiction to Donald Trump’s medical records which were published during the election campaign, in which his doctor said he is in “excellent health”.
But British cardiologist Dr Heck has rubbished the medical review, claiming Mr Trump is at “significant risk” of suffering a heart attack in the White House.
Speaking at a medical conference, Dr Heck, said: "I was quite surprised at the content of the doctor's report from Donald Trump's physician.
"For a man of 70, the high-octane campaign, sleepless nights and gruelling schedule particularly in the final few weeks of his campaign might well have exacted a toll on his heart."
Dr Heck added, for a man of Mr Trump’s age, he would normally be expected to live on average for another 14 years.
But the cardiologist warned the President-elect could die earlier due to the immense pressure he is now under.
Dr Heck said: "He is surely at significant risk of a heart attack."
Mr Trump’s medic Dr Harold Bornstein published a medical report into the Republican’s health in September.
He said the billionaire businessman, is overweight for his 6ft3ins height, weighing in
at 16 stone, nine pounds.
The report said Mr Trump takes statins for his cholesterol and a low dosage of aspirin, while echo cardiograms have come back with normal results.
Mr Trump is also teetotal and does not smoke, according to the report.
But Dr Heck poured cold water on the review, claiming Dr Bornstein wrote it in "five minutes whilst Mr Trump's limo waited outside".
One doctor claimed the President-elect's relationship with his 46-year-old wife Melania Trump could also impact his health.
The former model married the billionaire in 2005 and the couple share a son, Barron Trump, 10.
Gynaecologist Dr Karen Morton, of Dr Mortons said: "His personal life is surely a factor.
"His wife, Melania Trump, is beautiful and ambitious and will make certain demands as a young woman in her prime at 46.
"She will require time and energy.
"So let's hope he doesn't 'die on the job', or 'die in the saddle' or, as they say in France, 'la mort d'amour'!"
Throughout the campaign Mr Trump was known for his relentless schedule and despite flying across the country in his private jet would often fly hundreds of miles back to his New York home in the early hours to spend the night in his own bed.
He was also pictured enjoying Kentucky Fried Chicken and is said to be fond of Diet Coke.