Cardiac pacemaker in adult humans is about 70 beats per minute. Because the sinoatrial node is responsible for the rest of the heart's electrical activity, it is sometimes called the "primary pacemaker". If the SA node does not function properly and is unable to control the heart rate, a group of cells further down the heart will become the ectopic pacemaker of the heart. These cells form the Atrioventricular node (or AV node), which is an area between the left atrium and the right ventricle within the atrial septum, will take over the pacemaker responsibility. The cells of the AV node normally
Heart rate variability patients with acute MI. HRV was higher 90 minutes after thrombolysis in the patients with patency of the infarct-related artery. However, this difference was no longer evident when the entire 24 hours were analyzed. Exercise training may decrease cardiovascular mortality and sudden cardiac death. Regular exercise training is also thought to modify cardiac autonomic control. Individuals who exercise regularly have a 'training bradycardia' (i.e., low resting heart rate) and generally have higher HRV than sedentary individuals. The technique called "resonant breathing biofeedback" teaches how to recognize and control involuntary heart rate variability. A randomized study by Sutarto et al. assessed