Pacemaker current

The pacemaker current (If, or IKf, also called funny current) is an electric current in the heart that flows through the HCN channel or pacemaker channel. Such channels are important parts of the electrical conduction system of the heart and form a component of the natural pacemaker.

First described in the late 1970s in Purkinje fibers and sinoatrial myocytes, the cardiac pacemaker "funny" (If) current has been extensively characterized and its role in cardiac pacemaking has been investigated.[1][2][3] Among the unusual features which justified the name "funny" are mixed Na+ and K+ permeability, activation on hyperpolarization, and very slow kinetics.[1]

  1. ^ a b Brown HF, DiFrancesco D, Noble SJ (July 1979). "How does adrenaline accelerate the heart?". Nature. 280 (5719): 235–6. Bibcode:1979Natur.280..235B. doi:10.1038/280235a0. PMID 450140. S2CID 4350616.
  2. ^ DiFrancesco D, Ojeda C (November 1980). "Properties of the current if in the sino-atrial node of the rabbit compared with those of the current iK, in Purkinje fibres". The Journal of Physiology. 308: 353–67. doi:10.1113/jphysiol.1980.sp013475. PMC 1274552. PMID 6262501.
  3. ^ Baruscotti M, Bucchi A, Difrancesco D (July 2005). "Physiology and pharmacology of the cardiac pacemaker ("funny") current". Pharmacology & Therapeutics. 107 (1): 59–79. doi:10.1016/j.pharmthera.2005.01.005. PMID 15963351.