Road map guides clinicians to the heart of the matter

Story courtesy of WSLHD Research and Education Network News

Heart disease is the number one cause of deaths in Australia, claiming one life every 26 minutes.

Of these about 15,000 or 10 per cent occur suddenly, known as sudden cardiac death.

At Westmead Hospital, staff specialist cardiac electrophysiologist Dr Saurabh Kumar is trying to find ways to identify patients at the highest risk of sudden cardiac death.

At Harvard Medical School between 2013 and 2016, Dr Kumar collaborated with large French, Dutch and Australian academic hospitals on a project that led to the development of detailed electrical road maps of the heart in a variety of patients with conditions that lead to cardiac arrest.

This world-first research enabled clinicians and researchers to understand why the cardiac arrhythmias associated with cardiac arrest occur.

Broadly, there are three causes of sudden cardiac death: coronary heart disease; cardiomyopathy (a weakened heart, for example from a viral episode or heritable disorder of the heart muscle); and genetic disorders of the electrical channels in the heart, known as channelopathies.

At Harvard, Dr Kumar collected information on patients with the genetic mutation that leads to lamin cardiomyopathy, a genetic form of cardiomyopathy.

“We identified risk factors that increased the likelihood that patients with lamin cardiomyopathy would have a cardiac arrest,” Dr Kumar says. “We created, in detail, electrical road maps of the heart via small wires inserted through the groin and up into the heart, to try to identify why these arrhythmias that lead to cardiac arrest develop.”

A drawback to the creation of these electrical road maps is the invasive nature of the catheters. Dr Kumar is excited to be investigating the potential of new cardiac ultrasound technology.

“If we can get similar or even part of that information from ultrasound, then it would be a good first step,” he says. “It’s cheaper, non-invasive, and has no side effects.

“The most exciting part is that it means ultrasound may be applied to a much broader population to help identify patients who are most at risk.”

Cardiac arrhythmias can be treated with medication, pacemaker-like defibrillators, and more recently, a procedure known as ablation, which in the past 10 to 15 years has been conducted via special wires that travel from the groin to the heart.

“Most life threatening arrhythmias occur because of scar tissue within the heart,” Dr Kumar says. “An ablation procedure involves creating electrical road maps of the heart to identify scar tissue and cauterising those areas to prevent arrhythmias from recurring.”

Dr Kumar is also researching ways to improve and refine the ablation procedure.