Description of Condition:
Hypertension, or high
blood pressure, is one of the most common medical
conditions seen in the diving population - no surprise,
really, since it is a common medical condition in the
general population. Strict criteria for hypertension
can vary depending on the reference cited, but normal
blood pressure is generally accepted to be a systolic
pressure below 140 and a diastolic pressure below 90 mm Hg,
depending on age (cited as systolic first and diastolic
second. eg. "120 over 80," by your doctor). A thorough
medical evaluation should be performed to find a treatable
cause for hypertension; in most cases, however, none will be found.
Basically, two different sets of complications face a person
with hypertension: short-term and long-term. Short-term
complications are generally due to extremely high blood
pressure; the most significant is the risk of a stroke
due to rupture of blood vessels in the brain
(called a cerebrovascular accident). Long-term detrimental
effects are more common: they include coronary artery disease,
kidney disease, congestive heart failure, eye problems and
cerebrovascular disease.
Fitness and Diving Issue:
As long as the individual's blood
pressure is under control, the main concerns should be the
side effects of medication(s) and evidence of end-organ damage.
Divers who have demonstrated adequate control of blood pressure
with no significant decrease in performance in the water due to
the side effects of drugs, should be able to dive safely.
A recent report in a diving medical journal citing several
episodes of acute pulmonary oedema (ie. lungs congested with fluid)
in individuals with uncontrolled hypertension while they were diving.
Regular physical examinations and
appropriate screening for the long-term consequences of
hypertension such as coronary artery disease are necessary.
Medication used in Treatment:
Mild hypertension may be
controlled with diet and exercise; however, medication is often necessary.
Many classes of drugs are used to treat hypertension,
with varying side effects. Some individuals must change
medications after one drug appears to be or becomes ineffective.
Others might require more than one drug taken at the same time to keep
the blood pressure under control. Classes of drugs known as
beta-blockers often cause a decrease in maximum exercise tolerance
and may also have some effect on the airways. This normally poses no
problem for the average diver. ACE (angiotensin converting enzyme) inhibitors
are the preferred class of drugs for treating hypertensive divers;
a persistent cough is a possible side effect. Calcium channel
blockers are another choice, but lightheadedness when going from a
sitting or supine position to standing may be a significant side effect.
Diuretics are also frequently used to treat hypertension. This requires
careful attention to hydration and electrolyte status.
Most anti-hypertensive medications are compatible with
diving as long as the side effects experienced by the
diver are minimal and their performance in the water is not
significantly compromised. Any diver with long-standing high blood
pressure should be monitored for secondary effects on the heart and kidneys.
(James Caruso MD, Alert Diver, Jul-Aug 1999.)
-
Cardiovascular Topics
- Hypertension
- Coronary Artery Disease
- Myocardial Infarction (Heart Attack)
- Coronary Artery Bypass Graft
- Mitral Valve Prolapse
- Cardiac Dysrythmias
- Cardiac Mumurs
- Atrial & Ventrical Septal Defects
- Raynaud's Syndrome
- Patent Foramen Ovale (PFO)
- Heart Valve Replacement
- Pacemakers and Diving (.pdf)