Abnormal heart rhythm: what it means and how it’s treated
Posted on 1 June 2022
Heart just skipped a beat? It’s not just a figure of speech – abnormal heart rhythms are a medical condition that can be dangerous. An electrophysiologist (cardiologist specialising in heart rhythm disturbances) explains.
Your heart has one job: to keep steadily beating, pumping blood around your body. So, when your heart rhythm isn’t as rhythmical as it usually is, that’s a sign you shouldn’t ignore.
What is abnormal heart rhythm?
“Normally, electricity flows throughout the heart in a regular, measured pattern,” explains Dr Razeen Gopal, an electrophysiologist at Mediclinic Panorama. “This electrical system brings about heart muscle contractions. Sometimes, the electrical flow gets blocked or travels the same pathways repeatedly, creating a ‘short circuit’ that disturbs normal heart rhythms. A problem anywhere along the electrical pathway causes an arrhythmia, or heart rhythm disturbance.”
Different types of arrhythmias originate in different parts of the heart, Dr Gopal explains. These can then be further broken down into subtypes, each with its own causes and symptoms. The main types are:
- Atrial arrhythmias – originate in the filling chambers of the heart.
- Ventricular arrhythmias – originate in the pumping chambers of the heart.
- Supraventricular arrhythmias (SVTs) – involve the nervous system of the heart between the two chambers
“By accurately diagnosing the precise cause of an arrhythmia, it’s possible to select the best possible treatment,” Dr Gopal adds.
What are the causes?
The causes of arrythmia are often related to the type, says Dr Gopal. Atrial fibrillation, for example, is a subtype of atrial arrhythmia that’s associated with obstructive sleep apnoea, drinking too much alcohol, and hypertensive heart disease. SVTs, on the other hand, are often something you’re born with.
Recognising the symptoms
Common symptoms of abnormal heart rhythm include palpitations, lightheadedness, effort intolerance syncope (blackouts) and chest discomfort, says Dr Gopal. And you should never ignore them. “Depending on the arrhythmia, the risks may be very grave,” he cautions. “They include sudden cardiac death, heart failure, stroke, and a debilitating quality of life.”
Dr Gopal says some arrythmias can be treated with medication, but in general, ablation therapy is standard. “This is a non-surgical procedure where the tissue housing the short circuit is destroyed,” he explains. “It’s a relatively non-invasive procedure that involves inserting catheters – narrow, flexible wires – into a blood vessel, often through a site in the groin or neck, and winding the wire up into the heart. The journey from entry point to heart muscle is navigated by images created by a fluoroscope – an X-ray-like machine that provides continuous, ‘live’ images of the catheter and tissue.”
Once the damaged site has been confirmed via “electrical mapping” and testing, the surgeon destroys a small amount of tissue using either radiofrequency energy, which cauterises the tissue, or intense cold, which cryoablates (freezes) the tissue. This ends the disturbance of electrical flow through the heart, restoring a healthy heart rhythm.
While you’ll feel some discomfort, ablation is rarely painful and not something to fear. “Some patients watch the procedure on the monitors and occasionally ask questions,” says Dr Gopal. If you have symptoms of abnormal heart rhythm, see an electrophysiologist as soon as possible.