The reason why the sinoatrial node is a normal pacing point is that it is composed of very specific cardiomyocytes. These cardiomyocytes are highly autoregulatory and their main function is to be able to spontaneously generate and conduct impulses and to stimulate the atria and ventricles to cause the heart to beat. The sinus node generates and distributes impulses at the fastest rate, approximately 60-100 beats/min. Other myocardial tissues, such as the atrioventricular junctional area, are also capable of spontaneously generating and conducting impulses, but at a slower frequency of 40-60 beats/min. The ventricular myocardium also has its own autoregulation and is also capable of generating and conducting impulses, but is the slowest, at 20-40 beats/min. Since the sinus node generates and distributes impulses at the fastest frequency, it is able to effectively suppress the autoregulation of the atrioventricular junction and ventricular myocytes, for example, so that the sinus node can become a normal pacing point.