A heart attack, medically known as myocardial infarction, caused the death of singer KK, Calcutta police said on Wednesday citing preliminary post-mortem opinion.

Cardiologists said an adrenaline rush during the stage performance at Nazrul Mancha on Tuesday evening may have increased the singer’s blood pressure and pulse rate, which could have speeded up the development of the heart attack.

They said KK should have been taken to hospital immediately after he complained of discomfort during the concert, or spoke of feeling cold while being driven to his hotel and asked for the car air-conditioner to be switched off.

“According to the preliminary autopsy opinion, a myocardial infarction was the cause of death. However, the final opinion is awaited. It can be given only after the chemical examination report arrives,” a senior police officer said.

Police sources said KK had complained of pain in his shoulder and arm to his wife on Sunday, the day he left his family in Delhi and arrived in Calcutta.

Cardiologists said the warning signs of a heart attack can include profuse sweating and a sudden chill.

“During stage performances, an adrenaline rush is very common. This increases blood pressure and the pulse rate. In case of a heart attack during such a performance, the damage to the heart muscle can be faster compared with a person suffering the attack in a resting position,” said Debdatta Bhattacharya, interventional cardiologist at the R.N. Tagore International Institute of Cardiac Sciences.

“This is because of the heart muscle’s higher demand for oxygen. So, the process of heart attack is faster in such cases of adrenaline rush. Usually during such attacks, when a patient is brought to the emergency, the blood pressure and pulse rate are controlled with the help of medicines. This is an important strategy to treat a heart attack.”

The police said the post-mortem had found oedema (excessive fluid) in the lungs and haemorrhage in the brain.

“During myocardial infarction, the heart’s ability to pump blood diminishes, leading to increased pressure in the left ventricle of the heart. This increases the pressure in the pulmonary veins, causing leakage and pulmonary oedema,” Bhattacharya said.

The police said they had learnt that KK used to take tablets to address indigestion.

Programme arranger Tochan Ghosh, who spoke to KK’s wife and other family members on Wednesday, said he had been told the singer did not suffer from any ailments, new or old.

A cardiologist in Calcutta, Rabin Chakraborty, however, said there was a strong possibility that KK had undiagnosed coronary artery disease.

“About 45 per cent of sudden cardiac deaths are a result of coronary artery disease. About 50 per cent of coronary artery patients may remain undiagnosed despite the improvement in diagnosis and treatment. The first manifestation is a heart attack,” said Chakraborty, interventional cardiologist and vice-president of Medica Superspeciality Hospital.

“When KK said he felt unwell, he should have been taken to hospital immediately instead of to the hotel. That could have given doctors a better chance to revive him.”

Chakraborty said it was extremely important to have people trained in basic life support at places like Nazrul Mancha and hotels.

“When anyone collapses, they can be resuscitated by someone with basic life support training,” Chakraborty said.