Is Rapid Heartbeat Just a Benign Side Effect In Athletes?
Posted Sep 07 2008 2:15am
There has been news that elite athletes who were seemed healthy died during or after their games. As suggested by health experts, the athletes might have hidden heart disease and their death could be caused by the rapid heartbeat developed during the game.
Researchers from the Italian Olympic Committee in Rome found more evidence that the rapid heartbeat seen in many hard-training athletes is typically a benign side effect of physical conditioning. Their findings were published in July 2008 in the “American Journal of Cardiology”.
It is known that the heart rate for elite athletes is usually lower than the normal when they are at rest. However, when they are active, rapid heart rhythms known as ventricular tachyarrhythmia might be developed. In fact, up to 30 percent of those high-level athletes have irregular ventricular rhythms, as shown from previous studies.
People with ventricular tachycardia may have symptoms such as palpitations, shortness of breath, or lightheadedness, depending on the rate of the arrhythmia, its duration, and the underlying heart disease. Faster heart rates may cause athletes who already have underlying heart disease loss of consciousness (syncope) or even sudden death.
If the athletes have no underlying heart abnormality, the irregular rhythm is just the effects of training and is considered as a part of a benign condition known as ‘athlete’s heart’. Furthermore, there might be enlargement in the heart’s main pumping chamber of the athletes known as left ventricular hypertrophy (LVH).
Another feature of athlete's heart is an enlargement of the heart's main pumping chamber, known as left ventricular hypertrophy, or LVH. In non-athletes, pathological LVH usually increases the risk of ventricular tachyarrhythmia as it worsens. Therefore, in the current study, Italian researchers looked at whether there is a similar relationship in elite athletes.
The researchers studied 175 Olympic and world-class athletes using portable monitors to record their heart's electrical activity over 24 hours. They also had them undergo ultrasound scans to detect LVH. It was found that 14 percent of these athletes were found to have evidence of LVH, though there was no indication that LVH raised the risk of ventricular tachyarrhythmia.
From the findings, the researchers suggested that, in contrast to pathological cases, the ventricular arrhythmias found in elite athletes, are not caused by LVH-induced changes in the heart's electrical activity. In fact, it is the alterations in nervous system activity, brought on by high-level athletic training, should be responsible. Previous research had indeed shown that ventricular tachyarrhythmia does decline after athletes stop training and playing at a competitive level.
The findings do offer a measure of clinical reassurance about the benign nature of ventricular tachyarrhythmia in elite athletes and the expression of so-called athlete's heart.