Your heart’s electrical wiring is one of nature’s most sophisticated pieces of engineering. In that wiring, irregularities can sometimes occur. Arrhythmias are conditions in which the heart beats irregularly, and can pose serious health concerns. Some arrhythmias, along with some drugs used to treat serious arrhythmias, can be absolute contraindications to diving. However, with clearance and approval from a qualified physician, some patients with specific types of arrhythmias can scuba dive. As a dive professional, it’s important for you to be aware of arrhythmias and their effects on divers. Here’s an introduction to common arrhythmias:
Atrial fibrillation (or AFib) is the most common form of arrhythmia. Presenting as a fast and irregular heartbeat, AFib results from a disturbance of the electrical signals that make the heart contract in a controlled rhythm. In addition, AFib can cause blood to pool in the atria, promoting the formation of blood clots, and increasing the risk of a stroke. Common causes of the condition are hypertension and coronary artery disease. While some individuals may never experience AFib symptoms despite its presence, individuals with atrial fibrillation should seek qualified medical evaluation. Individuals who experience recurring episodes of AFib should refrain from further diving, as well as individuals on certain medications that can be used to treat AFib.
Extrasystole is a condition in which heart beats occur outside of the heart’s regular rhythm. Extrasystoles often arise in the ventricle and are referred to as premature ventricular contractions or PVCs. Studies have found that, when monitored for at least 24 hours, as many as 75 percent of healthy individuals have occasional PVCs. An extrasystole like a PVC is not generally felt, but it is followed by a pause as the heart’s electrical system resets itself. The beat following the pause is generally more forceful than a normal beat, and can be felt as a palpitation. Divers who experience PVCs should consult their physician. Most divers with benign PVC may be able to return to diving after a thorough evaluation by a cardiologist.
Syncope is an abrupt loss of consciousness, followed by a relatively quick recovery. The causes of syncope range from the relatively benign to the life-threatening. Because of the potential for loss of consciousness in, or around the water, syncope presents specific challenges to divers and aquatic staff.
The condition can occur in or upon exiting the water due to factors such as exertion, dehydration, and the normal return of blood volume to the extremities. Placing syncopal patients flat on their back in a cool environment may quickly restore them to consciousness. It’s recommended that people who are being evaluated for syncope refrain from diving. They may be cleared for diving at the discretion of their physician after the underlying causes of the symptoms have been identified and addressed.
For more information on heart health and diving, visit DAN.org/Health