The art of unmasking ‘phantom’ heart pains

Cork cardiologist and scientist Dr James Dollard has discovered biochemical truths about a puzzling heart condition, potentially offering better diagnosis. He talks to Claire O'Connell.

Artificial outline image of a jogger's body showing some vascular structure

Picture this: you feel pain in your chest when you walk or run. So you go to get it checked out, only to be told the coronary arteries that ferry blood to your heart look fine. Yet still the pain persists. You are sent home frustrated, or you are called back to undergo repeat tests that continue to draw blanks. 

It’s rare, but the pain can be down to Cardiac Syndrome X, a condition that has long perplexed cardiologists says Dr James Dollard. 

‘Every medical specialty has its black sheep’, says James, who is a consultant cardiologist at the Mercy Hospital in Cork. ‘This is the black sheep in cardiology – patients would present with this pain on exertion and you would bet the house on the coronary arteries being blocked, but they would look fine’. 

Still, there is something tangibly wrong: advances in imaging techniques have shown that in Cardiac Syndrome X, smaller arteries near the heart can become thickened and less able to widen on demand. So when the person exercises, the blood can’t get through the narrow arteries quickly enough and pain ensues.  

Slowly gathering patients 

James, a proud Corkonian who was inspired to study medicine thanks to family tradition, the challenge of the discipline and an interest in helping people, became interested in Cardiac Syndrome X while training as a cardiologist. So he did a HRB-funded PhD at University College Cork to find out more about patients with these ‘phantom’ pains.  

‘We looked at everyone coming in for a coronary angiogram and we found about 1.3% of them had Cardiac Syndrome X’, recalls James. ‘The rate was lower than I thought it was going to be, but still if we are doing 100 angiograms a week, that’s a patient each week who is not getting answers, or who is having to undergo repeat angiograms, which are invasive’. 

Given the relative rarity, it took a long time to gather the patients for the study, but James persisted and eventually involved 17 patients in the research.  ‘When I followed them up over 18 months, the pain resolved in 8 people but continued in 9 of them’, he recalls. ‘This meant I could compare the biochemistry of the people whose condition got better and the biochemistry of those who continued to feel this pain’. 

Biochemical signals 

What James discovered was a host of biochemical signals of inflammation in the patients with symptoms of Cardiac Syndrome X. He also found altered levels of an enzyme that could be linked with low mood – patients with the condition often report feeling depressed and anxious - and he identified changes in a specific molecule called microRNA 143, which may hasten muscle thickening around the small blood vessels.   

The findings offer biochemical clues both for the mechanics of the Cardiac Syndrome X and also to help identify patients who have the condition, which is an important step.

‘For the patient, having a label for the condition helps, and it is a reassurance that they are not about to have a heart attack’, says James. ‘Also if they have these biochemical signs it means they could get a diagnosis without the need for repeated invasive angiograms’. 

The HRB-funded research has led to several published papers in the medical literature and it has raised awareness among clinicians about the biochemical reality of this ‘phantom’ condition.  

‘It is a niche diagnosis, and doctors needed to know more about it’, says James, who has now set up clinic for Cardiac Syndrome X patients in Cork. 

Clinician scientist: double the benefit 

Being able to help patients doubly as both a clinician and a scientist helps James fulfil his goal to help people and to relish the diverse challenges that medicine poses.

‘Medicine is such a privilege’, he says. ‘The opportunity to do good deeds and to perform research to benefit everyone is enormous  - but helping the patients you meet day to day may not be enough. You need to help to advance the field that you're involved in. That's part of your professional legacy. When I [think about] the potential opportunities I had to do research compared to the other PhD students in UCC who were lab based, I had so many more possibilities due to my access to patients. It's our responsibility to do research to help these vulnerable people’.