Sudden Cardiac Death

What is Sudden Cardiac Death’s relation to athletes?

Sudden Cardiac Death (SCD) is described as a sudden stop in the beating of the heart. SCD can strike any age, race, or gender, however, SCD is found more prevalent in athletes under the age of 35. An inherited cardiovascular issue such as Brigade syndrome can cause SCD. Non-inherited issues such as coronary artery disease or a heart valve problem also can cause SCD. It is important to understand that SCD is different than a heart attack. SCD is due to a collapse of the normal circulation, most often due to ventricular fibrillation. A heart attack is due to a sudden blockage in the coronary artery, which causes death of the heart muscle. If you live in the Long Island, New York area, Dr. Kavesteen has the expertise and experience as a heart failure specialist to help you with a variety of cardiac conditions and diseases.

Genetic diseases affecting the cardiovascular system increase the risk of SCD, however, these types of issues can be detected by family history reports and screenings by physicians. SCD is a very serious condition due to the “sudden-ness” of the attack. Athletic activity can lead to alterations in the heart, increasing the risk of SCD, whereas in other situations, athletic activity can exacerbate an underlying, undetected cardiovascular condition. For those under the age of 35, the cause of SCD is most commonly related to an unappreciated structural heart disease or inherited arrhythmias, whereas in those over the age of 35, SCD is predominantly caused by coronary artery disease.

Prevention

Sudden Cardiac Death CAN be prevented. It is extremely important that any individual, no matter the age, that is engaging in any type of athletic training or activity have a thorough physical examination by a doctor. Physicians can identify conditions that may lead to SCD depending on the individual. Many tests can be done such as a resting EKGs, stress EKGs, and echocardiograms to identify these conditions. History of cardiovascular issues in the family of a patient can also lead the doctor to clues that could permit further testing. It is also important to not ignore symptoms such as palpitations, chest pains, or “blacking out” during any type of athletic exercise for these small symptoms can ultimately lead to SCD in some cases.

With locations in both Nassau and Suffolk County, Dr. Kavesteen offers preventative screening for various cardiac conditions and diseases. Especially if you are an athlete in the New York area, monitoring your overall heart function is key to not only a successful career but overall longevity.

Causes of Sudden Cardiac Arrest in Teen & Young Adult Athletes

Sudden Cardiac Arrest usually occurs in a setting with physical athletic activity, often in young, apparently healthy young adults. Extreme physical activity can aggravate an underlying and undetected physical heart condition. For people under the age of 35, the cause of Sudden Cardiac Death is due to structural heart disease or inherited arrhythmias. In contrast, for individuals over the age of 35, coronary artery disease is typically the predominant cause. The following cardiovascular issues could put you at risk for sudden cardiac death:

  1. Coronary Artery Anomalies: Some individuals are born with anatomical anomalies such as heart arteries that are connected irregularly. This can compress during exercise, resulting in improper heart blood flow.
  2. Myocarditis: An inflammation of the myocardium, which is the middle layer of the heart wall, that weakens the heart’s pumping ability, ultimately resulting in the failure of the heart to pump blood to parts of the body. This is typically caused by a viral infection.
  3. Hypertrophic Cardiomyopathy (HCM): Heart muscle becomes abnormally enlarged, which ultimately makes it harder for the heart to efficiently pump blood. This is the most common cause of sudden death in athletes, as it often goes undetected. Also, it is the most common cause of heart-related sudden death in individuals under the age of 30.
  4. Long QT Syndrome (LQTS): An inheritable heart rhythm disorder which results in rapid, disorganized heartbeats. These unsystematic heartbeats, which are caused by the sinoatrial node, can lead to fainting and potentially sudden death in young people.
  5. Brigade Syndrome: A potentially life-threatening heart rhythm disorder characterized by an abnormal heartbeat known as a “Brugada sign.” Brugada Syndrome is often an inherited condition. The syndrome doesn’t typically come with any symptoms so many individuals are usually unaware of their condition. A possible treatment for Brugada Syndrome is an implantable cardioverter-defibrillator.
  6. Commotio Cordis: Occurs when a “blow” to the chest triggers ventricular fibrillation. This results in the disruption of the heart’s rhythm and electrical cycle. Commotio Cordis is very common among young adult athletes and typically occurs when athletes get hit with, for example, a baseball or hockey puck in the chest area.
  7. Dilated Cardiomyopathy: The ventricles of the heart (usually the left) become enlarged and thin-walled, which can ultimately result in the inefficient pumping of blood and potentially heart failure. Some causes of Dilated Cardiomyopathy include genetic diseases, complications of substance abuse, and secondary changes after an infection of the heart. Individuals can treat this with an implantable cardioverter-defibrillator.

There are some symptoms that parents, coaches, teammates and others should be on the lookout for that may indicate a young individual with an increased risk of Sudden Cardiac Arrest:

  1. Unexplained fainting (syncope.) Specifically during physical activity, syncope could be an indication that there is something wrong with an individual’s heart.
  2. Family history of Sudden Cardiac Death. If family members have a history of unexplained deaths before the age of 50, individuals may also be at a higher risk for Sudden Cardiac Arrest. Specific screening options should be considered with the individual’s doctor.

What is The Microvolt T-Wave Alternans Test?

A microvolt T-Wave Alternans test (MTWA test) is able to show any problems that exist in an individual’s heart electrical system. A T-wave is a part of the electrical wave that is created by the heart when it beats. The MTWA test uses an electrocardiogram (ECG) measurement of the heart’s electrical conduction. The test looks for the presence of repolarization Alternans (T-wave Alternans), which is a variation in the vector and amplitude of the T-Wave component of the EKG. The amount of variation is small, on the order of microvolts, so sensitive digital signal processing techniques are required to detect TWA.

Most modern references to MTWA refer to a non-invasive heart test that can identify a patient who has an increased risk of Sudden Cardiac Death. The test can help medical professionals determine in an individual is at a high risk for types of heart failure such as Sudden Cardiac Death.

Why Should an Athlete be Tested?

Although rare, Sudden Cardiac Death should be alarming  because many of the victims are seemingly healthy, young, athletic adults. The idea of a healthy person suddenly succumbing to a sudden heart disease seems implausible. All young athletes, especially those who have a family history of heart disease, should incorporate the MTWA test into a physical in order to avoid heart failure during activity. Dr. Kavesteen offers comprehensive diagnostic screening tests for cardiac diseases including the Microvolt T-Wave Alternans Test, at his offices in both Nassau and Suffolk County, New York for athletes and non-athletes alike.

Athletes at risk for sudden cardiac death constitute a particular population of healthy people, in that they show a high prevalence of morphological cardiac alterations (a condition known as athlete’s heart), electrocardiographic abnormalities (wave voltage modification, ST and T-Wave changes) and frequent and/or complex ventricular beats. Athletes’ hearts undergo morphological adaptations, which can mimic a cardiovascular disease. Consequently, it is not easy to make a differential diagnosis with heart diseases at risk of sudden death, such as, for example, hypertrophic and dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy, which are often difficult to diagnose in their initial phase. The onset of these alterations in the athlete’s heart can be due to adaptation to dynamic sports activity and the impact of training on cardiac cavity size.

The detection of frequent and complex ventricular arrhythmias in a competitive athlete requires particular attention on the part of his or her cardiologist and sports physician in order to determine whether these arrhythmias have a good prognosis or are potentially life threatening. These detections can be made through a MTWA test.

Also, Medicare, as well as major insurers such as Aetna, Cigna, and Humana has approved use of the spectral method for measuring MTWA test for reimbursement.

Expectations

Before having a MTWA test at our Long Island based practice, we will require you to avoid eating several hours before the test, as well as avoid caffeine and tobacco. You must make us aware of all medications you are taking, including over the counter drugs, in order to make sure the test runs smoothly. Depending on your condition, we may ask you to stop taking medications such as beta blockers and heart medications, before the test is given.

The duration of the MTWA test depends on the individual, however, the test takes about 40 minutes. We will perform all pre-test paperwork and vitals before the preparation of the test. You will be asked to remove all clothes from the waist up and put on a gown. We will then prepare the skin for the strategic application of 14 electrodes to the body. These electrodes will be connected to wires which are connected to the MTWA equipment and are able to detect the electrical rhythm of the heart. The test begins activity on a treadmill or bike at a steady pace, but as time goes on, activity will become faster (no vigorous exercise.) During the test, your blood pressure and oxygen levels are monitored, in order to ensure your body is responding well to activity. When the test is over, we will remove the electrodes and take any resting vitals needed. A follow up appointment should be made by the individual with Dr. Kavesteen in order to read the test and results correctly.

What do the Results Mean?

MTWA results are given as positive, negative, or indeterminate. Those with indeterminate results can be tested again, however, positive and indeterminate results are often grouped together when making clinical judgments about the likelihood of Sudden Cardiac Death. Patients who show a negative (normal) MTWA test have a very low risk of Sudden Cardiac Death. The “Negative Predictive Value” of MTWA testing has been shown to be 98% accurate for follow-up periods of 12–24 months in various clinical studies. Patients receiving negative (normal) results should be retested every 12 months as cardiac function can change over time.

Positive or Indeterminate Result? Now what?

Several prospective studies have shown that detraining and physical deconditioning can result in cardiac reverse remodeling, with a reduction in cavity size, and in the reversibility of ventricular arrhythmias, which is complete in about 25% of subjects and partial in 50%.

The implantation of a cardioverter-defibrillator may also be a beneficial preventive measure of a patient showing a positive or indeterminate result. The defibrillator can stop an arrhythmia and save a patient’s life. For those with the implantation, can be stressful or traumatic, however, there are many coping mechanisms that can allow one to live a healthy normal life. These can be found here.