The pacing point of the heart to maintain a normal sinus rate is the sinus node, which is located anterolateral to the junction of the posterior wall of the right atrium and the superior vena cava and is the pacing point that controls the normal activity of the heart. The heart also has pathological pacing points as well as therapeutic pacing points. Ectopic pacing heart rate occurs when there is a sinus heart rate, an extremely slow heartbeat as well as sinus arrest, sinus block, and when there is sinus node malfunction. In this case, the heart may have atrial myocytes or ventricular myocytes as pacing points, which manifest on the electrocardiogram as atrioventricular junctional, ventricular escape or escape rhythm, which are passive ectopic beats. There are also ectopic autoregulatory cells, which may produce tachyarrhythmias when their frequency exceeds that of the sinus node, which are active ectopic beats and rhythms. When a patient has sick sinus syndrome an artificial pacemaker is required as a treatment, in which case the heart is paced from a pacemaker.