part one of the two-part online Boulder Community Health lecture, “Recognizing
and Treating Heart Problems in Athletes,” cardiologist
Molly Ware, MD, spoke about how athletes’ demanding workouts can sometimes trigger
physiological changes in the heart that can intensify an undetected heart
problem. In part two of this lecture, cardiac electrophysiologist
Samuel Aznaurov, MD, addressed arrhythmias (irregular heartbeats), syncope (unexplained and
temporary loss of consciousness) and sudden cardiac arrest in athletes.
Watch "Recognizing and Treating Heart Problems in Athletes."
Dr. Aznaurov started his presentation by explaining, “Arrhythmias
and syncope are things that we need to be aware of in those, such as athletes,
who are pushing their hearts.” He described the following:
Arrhythmias occur when the electrical impulses that coordinate your heartbeats aren’t
working properly. This causes your heart to beat too quickly, too slowly
or irregularly. A heart arrhythmia may feel like a fluttering or racing heart.
Syncope is a sudden, often unexplained and temporary loss of consciousness. “Syncope
can be a presenting symptom of arrythmia,” said Dr. Aznaurov.
The most common symptoms of syncope include:
- Blacking out
- Feeling lightheaded
- Falling for no reason
- Feeling dizzy
- Feeling drowsy or groggy
- Fainting, especially after eating or exercising
- Feeling unsteady or weak when standing
- Changes in vision, such as seeing spots or having tunnel vision
Types of Syncope
There are two types of syncope: benign and malignant. “Individuals
who have experienced syncope need a workup for us to understand whether
their case is benign or malignant,” said Dr. Aznaurov.
Benign syncope is the most common type. It is caused by a sudden drop in
blood pressure that in turn causes a drop in blood flow to the brain.
"This is similar to the woozy feeling that you may have experienced
when you stood up too quickly,” Dr. Aznaurov explained. “It
can occur with a sudden change in posture or from prolonged standing.”
While this may set off an inappropriate feedback loop, it’s normal.
What happens, explained Dr. Aznaurov, is that we experience:
- Slowed heart rate
- Decreased heart pumping action
- Dilation of blood vessels
Dr. Aznaurov stated, “These conditions can be exacerbated by dehydration,
medications, heat or situational factors, all of which point us in the
direction of this likely being a benign event.” He added, “While
these events are dramatic, they are not likely dangerous.”
Malignant syncope may arise from the presentation of life-threatening illness
such as an underlying cardiac or neurologic condition. Dr. Aznaurov said
that most can be successfully treated, but they must be diagnosed and
managed in a timely manner.
Features of malignant syncope that require medical evaluation include:
- If it was the result of an injury.
- If you lost consciousness when you were completely at rest or during peak exercise.
- If you needed chest compressions, CPR or lifesaving defibrillation when
you lost consciousness.
- If you were unconscious for several minutes.
He stated, “A nontraumatic syncope—that is, one not resulting
from concussion or injury — can be the main presenting symptom of
arrhythmia. And, exercise-related syncope always requires investigation
because it may be the only symptom that precedes a sudden cardiac death.”
Cardiac Arrhythmia and Sudden Cardiac Arrest
Congenital arrhythmia syndromes can cause sudden cardiac arrest. They tend
to be associated with a family history of sudden death. There are some
conditions that result from an inherited structural abnormality. They include:
Hypertrophic cardiomyopathy (HCM) - HCM is a genetic disease that causes the heart muscle to become abnormally
thick and stiffen. This makes it harder for the heart to pump blood. It
often goes undiagnosed because people with the condition may have no symptoms.
However, the thickened heart muscle can cause problems in the heart's
electrical system, resulting in life-threatening abnormal arrhythmias
or sudden death. Although deaths from sudden cardiac arrest are rare,
HCM is thought to prompt 30 to 40 percent of sudden deaths in young athletes.
Arrhythmogenic (right) ventricular cardiomyopathy (ARVC) – As a genetic condition, ARVC is an issue with the proteins that
bind the heart's muscle cells together. This results in accelerated
“wear and tear” of the muscle, causing the heart’s ventricles
(lower pumping chambers) to become thin. ARVC can affect the electrical
activity of the heart, leading to dangerous arrhythmias. About 20 percent
of sudden death in young athletes result from ARVC. “If you carry
the gene for this disorder and don’t exercise much, you will be
safer than if you do exercise. This is very uncommon in the general population,
less common in women, but very overrepresented in the population of athletes
who experience sudden death,” said Dr. Aznaurov.
Anomalous Coronary Artery – This is a much more common condition, half are typically benign. It occurs
when the aorta causes a pinch in the artery and that pinch impedes blood
flow, which can also cause arrhythmia. “However,” Dr. Aznaurov
notes, “it’s responsible for 10 to 15 percent of sudden death
occurrences in young athletes.”
ION Channel Disorders –These are predispositions toward cardiac arrest in a structurally
normal heart with mutations involving cardiac ion channels. There are
three major categories: potassium, calcium and sodium channel disorders.
Dr. Aznaurov noted, “All are extremely rare. Your risk does however
increase if you have a family history of this disorder.”
Atrial Fibrillation in Athletes
“The much more likely arrhythmia that athletes experience is atrial
fibrillation, or AFib” said Dr. Aznaurov. “This is a disorganized
rhythm in the atria, the non-pumping chamber of the heart," he explained.
“Athletes ask a lot of their heart and have a much higher risk of
AFib than the general population because of the wear and tear they place
on their heart,” said Dr. Aznaurov.
In fact, atrial fibrillation is present in about 15 percent of masters
athletes. “In younger athletes, the risk factor may be related to
a history of intense exercise. The highest risk group is middle-aged men
with a history of more than 10 years of strenuous exercise,” he said.
Immediate effects of AFib include:
- Elevated heart rate
- Palpitations, fatigue, lightheadedness
- Exacerbation of underlying heart and/or lung conditions
In the long term, it can result in stroke or heart failure. Factors include:
- Cardiac disease – hypertension, diabetes, heart failure, valvular disease
- Non-cardiac disease – lung disease, sleep apnea, thyroid, anemia,
alcohol/drug use and other issues
“It’s a progressive and a very individual disease. This means
that treatments aren’t one-size-fits-all.”
Detecting — or Ruling Out — Heart Disease in Athletes
Make an appointment with a
Boulder Heart cardiologist if you’re an athlete and experience any of the following symptoms:
- Chest pain or pressure
- Unusual shortness of breath
- Unusual heart racing/skipping
- Unexplained decline in exercise tolerance
Boulder Heart uses the latest heart technologies to diagnose potential
heart problems in athletes, including imaging and stress tests. They can
also evaluate whether your symptoms are related to physical activity or
something more serious.
To make an appointment with a
Boulder Heart cardiologist, call
Click here to view/download a PDF of slides shown during this lecture.