THE most common irregular heart rhythm — atrial fibrillation (A. fib) — is increasing in prevalence from age 50-60 and affecting one in four adults by the time they reach 80 years old.

This irregular heart rhythm occurs when the upper chambers of the heart (the atrium), instead of contracting as one unit, vibrates with multiple segments doing their own contraction. A. fib can cause a number of problems.

One problem is an irregular heartbeat akin to a child sitting behind a set of drums — unpredictable and with no set timing. It can cause the heartbeat to vary in speed, between slow and very fast (palpitations). In some cases this tachycardia (heart rate over 100 beats per minute) is so fast that it prevents the heart from filling properly. This reduces the amount of blood that leaves the heart and can cause hypoperfusion (decrease blood flow) to the brain, which leads to a person feeling faintish or even blacking out (syncopy). Rarely this can cause death.

A second problem is that it can lead to decreased cardiac function (heart failure). Persons with prolonged A. fib can see a slow decline in their heart function, especially if the heart is beating fast.

The third and most common and devastating effect of A. fib is that it causes strokes. One in every five strokes is due to atrial fibrillation. As the atrium is not contracting properly, blood can settle in the chamber and then form clots. These clots can then get loose, travel to the brain and cause a stroke. For this reason many persons with A. fib are on blood thinners and anyone who has had a stroke should be investigated for A. fib.

With these potential effects it becomes very important to detect and treat the condition. Treatment usually involves medication to control the heart rate, blood thinners (anticoagulants), and medication to try and maintain a normal rhythm. The latter has about a 50 per cent success rate.

Today, more effective therapy is available for patients who have paroxysmal (intermittent) A. fib.

On May 27, at Partners Interventional Centre of Jamaica (PICJ), a therapy called cryo-ablation was performed for the first time in Jamaica. This involved a specialised team involving Dr Nordia Clare-Pasco, cardiac electrophysiologist; Dr Lisa Hurlock, cardiologist specialist in transoesophageal echocardiogram; Dr Cleopatra Patterson, anesthesiologist; plus nursing and technical staff.

Cryo-ablation has an 80 per cent success rate in keeping persons with paroxysmal or persistent — two types of intermittent A. fib — in normal rhythm, hence reducing their risk for syncopy, heart failure, and having a stroke. It does not work, however, for persons with permanent A. fib. This emphasises the importance of treating paroxysmal A. fib before it becomes permanent.

Cryo-ablation involves passing a special catheter through a vein in the groin, up to the heart, and entering the left atrium. A balloon is then applied to the base of the four pulmonary veins which are responsible for providing blood to the left atrium. The balloon is then filled with liquid nitrogen which drops the temperature to between -40 to -60 degrees Fahrenheit. This provides a cold burn to the tissues where the electrical activity for A. fib originates, blocking them from causing the atrium to fibrillate.

This procedure is part of the comprehensive stroke programme that is being developed at PICJ.

“Treating persons with paroxysmal A. fib — knowing that you are improving their heart function and reducing their stroke risk — is exciting, and to introduce this new procedure to Jamaica is a dream come true” said Dr Elliott, managing director of PICJ.