atrial ectopic foci originating from the anterior and posterior walls of the right atrium

arrow axis human body anatomical ecg education recording heartbeat duration heart rate rhythm cardiology electrocardiography electrodes monitoring electrode electrocardiograph theory cardiovascular medicine cardiogram cardiac anatomy beat cardiac depolarization diagnosis disease ekg electrocardiogram ventricle cycle atrial foci right atrium left arrhythmia ectopic pulsation premature anterior contraction wall posterior septum electric potential excitation 3d chest lead wave