For the typical adult, the heart beats 60-100 times per minute. This rate increases during periods of increased demands on the body. Specifically, it needs to beat faster in order to pump more oxygen-rich blood to the muscles, such as during exercise. This can also occur due to other triggers, such as pain, dehydration, or arrhythmias. It is important for your physician to evaluate you to determine the specific cause of this sensation.
Some common arrhythmias include atrial fibrillation, atrial flutter, atrioventricular reciprocating tachycardia, AV nodal reentrant tachycardia, or atrial tachycardia. More uncommonly, it could be due to a ventricular arrhythmias, such as ventricular tachycardia, which originates in the ventricles, or bottom chambers of the heart. In some instances, this arrhythmias can cause your heart to beat so quickly that it cannot adequately fill with blood between beats. As a result, your body may not be receiving enough oxygen, which can cause lightheadedness, difficulty focusing, or loss of consciousness. Given your sensation of a racing heart beat and difficulty concentrating, it is imperative for you to see your primary care physician
for further evaluation. A typical evaluation consists of a thorough history and physical exam and EKG. Depending on these findings, it is possible you would need to undergo a transthoracic echocardiogram
of your heart), treadmill exercise test, or 24-hour EKG monitor. Again, I urge you to seek consultation with your physician to help determine the next steps in your evaluation.