What heart health issues should be considered before scuba diving?

I’ve been an active diver for more than two decades and try to get into the water every couple of months. But when I hit the big 5-0 earlier this year, I started evaluating my lifestyle to make sure that I’m keeping up with my exercise, cutting down on stress and keeping an eye on my diet. What are some things I should consider in relation to my heart health and dive schedule?

Heart health is one of the most important considerations in any evaluation of an individual’s fitness to dive. Divers with abnormalities in the function or structure of their heart risk serious health complications and an increased risk of cardiac-related deaths. Nearly one-third of diving fatalities are associated with an acute cardiac event. Heart health is a complex and multifaceted issue, but major cardiac risk factors are few and straightforward.

Hypertension
Hypertension, or high blood pressure, effects almost one-third of Americans and was considered to be a contributing factor in 348,000 American deaths in 2009. Hypertension directly increases an individual’s risk of heart attack, stroke and chronic heart failure, and the rigors of a strenuous diving environment can exacerbate some of these risks. Mild hypertension can often be controlled with diet and exercise, although medication might be required to treat more serious cases. Divers should be aware of the dehydrating effects of some common medications used to treat hypertension when considering their fitness to dive.

Hyperlipidemia
Hyperlipidemia is another condition that affects heart health, and it can increase a diver’s risk of death or injury during a dive. Defined as an abnormally high concentration of cholesterol in the blood, hyperlipidemia can increase an individual’s risk of arterial diseases, heart attack and stroke. Hyperlipidemia can contribute to the stiffening or partial blockage of arteries due to buildup of a form of cholesterol called low-density lipoprotein (LDL). This buildup can contribute to hypertension and impede the flow of blood to the heart, brain and other organs. Current recommendations are that individuals should have their cholesterol levels checked every four to six years and consult with their healthcare providers to determine their risk for cardiovascular disease and stroke.

Obesity
Obesity is a risk factor for many heart diseases that is often overlooked. While there are no direct statistics on the number of obese divers, 69 percent of the adult American population is either overweight or obese, and there is no current data to suggest that the diving population is an exception to that trend. Obesity often presents with a lowered capacity for physical activity, and both of these factors can negatively affect your ability to respond to physical stressors of the diving environment. Obesity is often associated with hypertension and hyperlipidemia, as well as diabetes and a number of other cardiac-related conditions. Obesity can be treated through diet and exercise in consultation with your healthcare provider.

Heart health is a complex and multifaceted issue, but major cardiac risk factors are few and straightforward.

Metabolic Syndrome
When hypertension, obesity and hyperlipidemia present together, they can be indicators of a condition called metabolic syndrome. Metabolic syndrome is a disorder that affects how the body stores and uses energy. The syndrome can limit a diver’s ability to exercise, increase his or her risk of heart attack and stroke, and increase the risk of an incident occurring under strenuous diving conditions. The risks of metabolic syndrome can be mitigated through diet and exercise in consultation with a healthcare provider and treatment of the contributing conditions. Treatment for metabolic syndrome is varied and dependent on the number and severity of contributing conditions, but it should always be considered with other heart-health concerns when reviewing your fitness to dive with a qualified healthcare provider.

For more information on heart health and diving, visit dan.org/health.

Straight from the Heart
Improved cardio fitness not only lowers your chance of DCS, but it also comes with plenty of other benefits.

Increased cardiovascular fitness has been shown to decrease the incidence and severity of decompression sickness and increase a diver’s safety in the water. Exercising for 90 minutes or more per week at a moderate to high intensity level is an excellent way to ensure your fitness to dive, and improve your overall physical health. Increasing your aerobic fitness through additional exercise improves not only your ability to dive, but it can also decrease your risk of developing heart disease, diabetes, obesity and hypertension. Traditional forms of exercise such as riding a bike, jogging, or swimming laps are proven methods to increase aerobic fitness, but you can perform cardiovascular exercise in numerous other ways. Going for a brisk walk, playing tennis and even mowing the lawn can be excellent forms of exercise, as long as you perform them at a high intensity and focus on raising your heart rate above 50 percent to 70 percent of its maximum level. For more information on dive fitness, dan.org/health.