THE TELLTALE HEART

– THE DIAGNOSTIC POSSIBILITIES OF HRV

HRV is not only a measure of emotional stability through its connection with the autonomic nervous system. It has potential as a valuable non-invasive diagnostic marker too. “If you have a patient in hospital who has survived the acute phase of a heart attack, before the patient is discharged, one could measure HRV over 24 hours using an electrocardiogram, and you would get an indication of whether the patient is at higher or lower risk,” says Dr Marek Malik, emeritus professor of cardiac electrophysiology at Imperial College London.

Other diseases of the autonomic nervous system can be detected and monitored using HRV, such as autonomic neuropathy – damage to the nerves that control everyday functions. This can be caused by autoimmune diseases such as diabetes. “If I had a patient with diabetes, and I was concerned whether they already had some nerve damage due to the diabetes, I could investigate this using heart rate variability,” explains Malik.

Using HRV for diagnosis is still largely at an experimental stage, but there are also indications, says Malik, “that it could be very useful in differentiation in patients of whether they need an automatic defibrillator implanted or not.” These defibrillator devices can resuscitate some people after heart attacks, but not others, depending on their heart rhythm. However, he warns, these serious health diagnostics are only possible when carried out by doctors and experts with years of training and experience, who use specialist equipment. Consumer heart monitors and HRV apps are not suitable for medical use.