The human heart is a sophisticated electrical pump that never stops circulating blood throughout the body. You have a 24/7 contract with your heart, so it’s always working hard. In an average lifetime, it will pump about 48 million gallons of blood.
Divers’ hearts face an additional burden when underwater. The pressure of water on the body shifts some of the body’s blood to the chest cavity, creating more work for the heart muscle. Additional factors such as stress and being cold can also make an impact on circulation. In the context of this increased workload, cardiac problems are a leading cause of dive fatalities.
When you’re diving, your heart is constantly working to keep your body properly functioning and in a balanced state. The heart’s importance and the inherent hazards of the underwater environment make it really important for divers to be aware of their cardiovascular health.
CONDITIONS OF THE HEART
Some heart conditions and diseases are hereditary, while others are preventable through healthy behaviors, interventions and precautions. Ischemia is a condition in which blood flow is restricted in a part of the body because of narrowed arteries. Ischemic heart disease can predispose affected individuals to a heart attack. Valve disorders affect how blood is pumped through the heart. Two examples of valve disorders that may be relevant to divers are mitral valve prolapse (in which the mitral valve doesn’t close properly) and valvular regurgitation (in which a leaky valve causes blood to flow backward). With arrhythmias, which include atrial fibrillation, extrasystoles and ventricle fibrillation, the normal heartbeat or rhythm might be interrupted or irregular.
These conditions are affected by various factors—some are modifiable; others are not. Lifestyle risk factors such as smoking, high blood cholesterol, inactivity, high blood pressure and diabetes can be monitored and controlled through lifestyle changes. Some other risk factors, however, such as gender, ethnicity, heredity, age and a history of stroke or heart attack must simply be managed as well as they can be. Finally, some individuals are just predisposed to heart disease or other conditions regardless of any risk factors. In all scenarios, it’s important that divers consult their doctors regularly.
WHY DIVE-CENTRIC HEART RESEARCH?
Cardiac research in diving is incredibly important: About 25 percent of diver deaths are caused by cardiac problems. This high mortality rate is largely due to heart disease being the leading cause of death in the United States, Europe and elsewhere. Furthering the need for dive-related cardiac research is the increasing median age of divers.
But cardiac-related deaths could be more prevalent than we realize: Cardiac issues underwater can act as triggering events or disabling injuries that ultimately result in death. A diver’s cause of death might be drowning, but that could have resulted from a cardiac incident.
New research will help those in dive medicine understand the correlations between the aging dive community and cardiac problems. With up to-date research, doctors will be better able to treat divers with heart problems.
HEART WARMING
It’s incredibly important for everyone in the dive community to appreciate the link between heart health and diving, as cardiac events can happen anywhere. If a diver is on a boat or beach during a heart attack, chances of survival are lower than if the person were in a metropolitan area where first responders are nearer.
While there is no specific age at which a diver should stop diving, heart health may deteriorate gradually as divers age, increasing health risks. Divers of all ages should understand their personal risk and work with their doctors to stay healthy and dive safely.
For more information, visit dan.org.
By Divers Alert Network April 1, 2021
