The death of a woman was not caused by a “technical error” during life-saving heart surgery, an inquest heard.

Pramila Sakaria, from Wyatts Road, Chorleywood, died on February 26 at Watford General Hospital, a week after complaining of chest pains.

Doctors discovered the 75-year-old had severe disease of the coronary artery, the vessel which provides blood to the heart's muscle.

After fixing the damaged artery, a wire installed to control Mrs Sakaria's heart beat caused a small hole in her right ventricle, allowing blood to leak into the pericardium, the sac around the heart.

Rowena Smith, consultant pathologist, said the blood around her heart, although only 100ml, stopped it from beating properly, leading to her death.

Mrs Sakaria's GP diagnosed her with high cholesterol and high blood pressure, as well as adult onset asthma, and later diabetes, putting her at risk of coronary heart disease.

She lived with her son Raj and his wife, who said: “She was well built, which did not help her cholesterol situation, but she was a very fit lady for 75, we kept her under out wing.”

After complaining of chest pains, staff at Watford General Hospital, suspecting coronary heart disease, elected to carry out further examination.

A hollow needles and wire is inserted into the femoral artery in the leg, a tube is then placed over the wire to provide a port into the arterial circulation.

The procedure allows doctors to asses the condition of the coronary artery, patient is given local anaesthetic and is conscious.

Consultant interventional cardiologist Will Wallis said: “The angiogram was undertaken on February 25, started by my registrar Dr Andrew Marshall, and something unusual happened almost immediately.

“The patient became very unstable, showing signs of a heart attack, due to an acute blockage of the coronary artery at the moment of the procedure.

“Nothing about Dr Marshall's conduct was anyway unusual, there was a nurse watching him like a hawk as well, it was all textbook stuff. It is clear in my mind he did not make a technical mistake.

“I immediately took over the case, the patient continued to have a heart attack and low blood pressure, and the heart stopped beating as strongly as it should.

“The right coronary artery, which was thought to be the culprit, was extremely difficult to examine, but was eventually achieved by me using an unusually shaped catheter.

“The artery was blocked, and I wished to open it, which is difficult but possible. The requirement to open the artery was accelerated by the heart attack, it was paramount.”

The heart attack had affected the muscle but also the heart's electrical system, so a temporary pacing wire was put into the right ventricle, providing electrical stimulus to make the heart beat.

Dr Wallis said: “The bpm slowed down very abruptly to 20-25 beats per minute, which is very unstable and dangerous, we have to put in the wire immediately to make the heart beat again. There was only a few minutes to play with or the patient would die.

“The pacing wire has plastic insulation up to a silver tip which is placed against the heart muscle, it is very unlikely to cause damage as it is a soft wire which makes it difficult to perforate the muscle.

“However, it is possible during a heart attack that the muscle becomes inflamed, the mechanical characteristics can change and and would allow the wire to push through what was originally a resistant material.”

Mrs Sakaria deteriorated over night and died the day after.

Rowena Smith, consultant pathologist confirmed the perforation in the right ventricle, and also discovered severe coronary heart disease, about 80% blocked, which could be a cause of death on its own, and that there was no signs of a tear being made during the operation.

Dr Wallis said: “I always take responsibility for the death, without hesitation, I am responsible for that patient's care and I take that responsibility very seriously.

“The correct thing to do was to look inside, I would do the same thing even knowing was occurred, it was the correct decision even though it had the wrong outcome.”

Coroner Edward Thomas said: “When someone dies suddenly and unexpectedly it's only when you have the post mortem that you can have a definite idea of what happened.

“One of the worrying things about my job is that sometimes people seem very healthy but the post mortem discover severe coronary heart disease.”

He then recorded death by a recognised complication of an operative procedure.