KIN408 Lecture Notes - Lecture 15: Long Qt Syndrome, Electrical Conduction System Of The Heart, Purkinje Fibers
6 Aug 2019
School
Department
Course
Professor
Document Summary
Recall the cardiac conduction system: originates in the sa node spreads via gap junction. The path: sa node atrial cardiomyocytes av node bundle of his and bundle. Changes in action potential morphology across cell types: these are what action potentials look like in the different cell types in the heart. These are the changes in membrane potential in each cell (i. e. what it looks like in 1 cell) (cid:9) The ventricular cardiomyocyte action potential: phases, phase 4 diastole. Membrane potential (em) is -90mv: phase 0 depolarization is triggered via a neighbouring cardiomyocyte or purkinje fibre. Na+ channels opem na+ enters the cell rapid depolarization, quick closure of these channels: phase 1 early repolarization. Some k+ channels slowly open and this lowers membrane potential slightly: phase 2 the action potential plateau. And more k+ channels open and repolarization continues. What is long qt syndrome (lqts): lqts is a genetic disorder characterized by alterations in the electrical activity of the heart.
