Supraventricular and ventricular heart arrhythmias cause a fast heart rate. Atrial fibrillation is the most common type. The condition is characterized by the atria beating too fast combined with irregular contractions. Treatments often include medications, surgery or nonsurgical procedures.Wolff-Parkinson-White Syndrome causes premature ventricular contraction. This occurs due to an extra electrical pathway that disrupts the timing of the heartbeat. Another condition, known as ventricular fibrillation, causes the ventricles to quiver instead of pump.Sufferers of ventricular fibrillation are subject to cardiac arrest. Cardiac arrest occurs when the body receives insufficient amounts of blood. Always seek emergency medical attention for a racing heartbeat, as it can signal one of these life-threatening conditions.Next
