Atrial action potential

In electrocardiography, the atrial action potential are action potentials that occur in the heart atrium. They are similar to ventricular action potential with the exception of having a more narrow phase 2 (plateau phase) due to a smaller calcium influx. Also, in comparison to the ventricular action potential, atrial action potentials have a more gradual repolarization period. This indicates that the atria's repolarization currents are not very large and they do not undergo a large repolarization peak.^[1]

References

^ Vigmond E.J, Tsoi V, Yin Y, Page P, & Vinet A. (2009). Estimating Atrial Action Potential Duration from Electrograms. IEEE Transactions on Biomedical Engineering (pp. 1546-1555). Vol. 56, No 5. Retrieved on March 27, 2012.

Physiology of the cardiovascular system

Heart

Cardiac output	Cardiac cycle Cardiac output Heart rate Stroke volume Stroke volume End-diastolic volume End-systolic volume Afterload Preload Frank–Starling law Cardiac function curve Venous return curve Wiggers diagram Pressure volume diagram
Ultrasound	Fractional shortening = (End-diastolic dimension End-systolic dimension) / End-diastolic dimension Aortic valve area calculation Ejection fraction Cardiac index Left atrial volume
Heart rate	Cardiac pacemaker Chronotropic (Heart rate) Dromotropic (Conduction velocity) Inotropic (Contractility) Bathmotropic (Excitability) Lusitropic (Relaxation)
Conduction	Conduction system Cardiac electrophysiology Action potential cardiac atrial ventricular Effective refractory period Pacemaker potential Electrocardiography P wave PR interval QRS complex QT interval ST segment T wave U wave Hexaxial reference system
Chamber pressure	Central venous Right atrial ventricular pulmonary artery wedge Left atrial ventricular Aortic
Other	Ventricular remodeling

Vascular system/
hemodynamics

Blood flow	Compliance Vascular resistance Pulse Perfusion
Blood pressure	Pulse pressure Systolic Diastolic Mean arterial pressure Jugular venous pressure Portal venous pressure Critical closing pressure
Regulation of BP	Baroreflex Kinin–kallikrein system Renin–angiotensin system Vasoconstrictors Vasodilators Autoregulation Myogenic mechanism Tubuloglomerular feedback Cerebral autoregulation Paraganglia Aortic body Carotid body Glomus cell