Upload File

15 electrical activity-cardiac action potential 2012-1

  • Home
  • Documents
  • 15 Electrical Activity-Cardiac Action Potential 2012-1
prev
next
out of 20
Download 15 Electrical Activity-Cardiac Action Potential 2012-1

Upload: jumpman52391

Post on 04-Apr-2018

218 views

Category:

Documents


0 download

Report

TRANSCRIPT

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    1/20

    CARDIAC ACTION POTENTIAL

    Howard Mass, Ph.D.

    2012

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    2/20

    2

    The SA node originates an actionpotential that subsequently spreads

    through the cardiac chambers. Thenumbers on the heart illustrate inmilliseconds the elapsed timeinterval between the origin of thedepolarization at the SA node andthe appearance of thedepolarization in the differentregions of the heart. The tracing onthe right shows the temporalrelationship between themyocardial action potentials and theECG. The P wave represents atrialmuscle depolarization, the QRScomplex represents ventricularmuscle depolarization, and the Twave represents ventricular musclerepolarization.

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    3/20

    3

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    4/20

    Membrane Channels

    Ungated Potassium

    Voltage-Gated Sodium

    Voltage-Gated Calcium

    Voltage-Gated Potassium

    4

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    5/20

    Voltage-Gated Potassium (cont.)

    Inward rectifying

    Delayed Rectifying

    5

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    6/20

    6

    -80 mV

    +60 mV

    Phase 0(upstroke)

    Phase 2 (plateau)

    Phase 1(early repolarization)

    Phase 4 (diastole)

    Phase 4 (diastole)

    Phase 3 (repolarization)

    Phases of the Cardiac Action Potential

    (AP)

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    7/207

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    8/208

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    9/209

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    10/2010

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    11/2011

    Nodal Action Potential

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    12/20

    Phase 4

    Phase 0

    Phase 3

    12

    What ions/currents are responsible for the nodal action potential?

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    13/20

    13

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    14/20

    Autonomic Control of Cardiac Function and

    the Cardiac Action Potential

    Effects of Autonomic NS control:

    Chronotropic

    Dromotropic

    Inotropic

    Lusitropic

    14

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    15/20

    Chronotropy

    15

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    16/20

    16

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    17/20

    Dromotropy

    17

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    18/20

    Inotropy

    18

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    19/20

    19

    Channel Gatingmechanism

    Functional role

    K+

    channel (inward rectifier)

    Voltage

    Maintains high K+

    permeability during phase 4

    Its decay contributes to diastolic depolarization

    Its suppression during phases 0 to 2 contributes to plateau

    Na+

    channel (fast)

    Voltage

    Accounts for phase 0 of action potential

    Inactivation may contribute to phase 1 of action potential

    K+

    channel (transient outward)Voltage

    Contributes to phase 1 of action potential

    Ca2+ channel (slow inward, L channels) BothContributes to phase 2 of action potential

    Inactivation may contribute to phase 3 of action potential

    Is enhanced by sympathetic stimulation and

    -adrenergic agents

    K+ channel (delayed rectifier) VoltageCauses phase 3 of action potential

    Is enhanced by increased intracellular Ca2+

    K+

    channel (ATP-sensitive)Increases K

    +permeability when [ATP] is low

    K+ channel (acetylcholine-activated) Ligand

    Responsible for effects of vagal stimulation

    Decreases diastolic depolarization (and the heart rate)

    Hyperpolarizes resting membrane potential

    Shortens phase 2 of the action potential

    Na+ (pacemaker current) Both

    Is activated by hyperpolarization and contributes to the

    diastolic depolarization

    Is enhanced by sympathetic stimulation and

    beta-adrenergic agentsIs suppressed by vagal stimulation

  • 7/30/2019 15 Electrical Activity-Cardiac Action Potential 2012-1

    20/20

    Effect of Ion Disturbances on the

    Action Potential:

    Hyperkalemia

    Hypercalcemia

    20


Electrical alternans in cardiac tamponade - Thoraxthorax.bmj.com/content/thoraxjnl/30/2/228.full.pdf · Electrical alternans in cardiac tamponade. ... pose of this paperto report

Resting potential, action potential, and electrical excitability. … · 2019-10-04 · skeletal muscle cells APs last a few ms, whereas the length of cardiac APs is much longer,

Cardiac Action Potential - Yolasalahmartin.yolasite.com/resources/Cardiovascular_Physiology/... · Cardiac Action Potential Graphics are used with permission of: adam.com ( ... **

CARDIO HISTOLOGY 2 CARDIAC PHYSIOLOGY 7 ......Physiology of Cardiac Electrical System Electrical Conducting System = System of fast conducting specialized cardiac muscle cells (NOT

Arrhythmias. Cardiac dysrhythmia Cardiac dysrhythmia (arrhytmia) Abnormal electrical activity in the heart

Antiarrhythmic Drugs Background of Cardiac Electrophysiology Membrane potential of cardiac cells Fast response : resting potential, High -80 ~ -95mv (Atrial

Interventions for Clients with Dysrhythmias. Cardiac dysrhythmias are disturbances of cardiac electrical impulse formation, conduction, or both Cardiac

Patient with an implantable cardiac electrical stimulation

Two Components of the Cardiac Action Potential I. Voltage-time … · 2020-06-15 · Two Components of Cardiac Action Potential 6I the beginning and the end of the potential change

Electrical Cardiac Monitoring in the Head for Helmet

Drugs affecting cardiac action potential

Natural glycosides & therapeutic potential Of Cardiac Glycosides

Electrical Potential Difference and Electrical Potential Energy

Modeling of Electrical Conduction in Cardiac Tissuemacleod/bioen/be6460/notes/W05-cell-sim-1.pdfModeling of Electrical Conduction in Cardiac Tissue ... Bidomain Modeling of Electrical

Electrical stimulation systems for cardiac tissue engineering

Determination of Cardiac Ejection Fraction by Electrical ...€¦ · 0 Determination of Cardiac Ejection Fraction by Electrical Impedance Tomography Franciane C. Peters 1, Luis Paulo

Electrical Potential & Electrical Energy - Physics In …€¦ · Electrical Potential & Electrical Energy Units • Electric Potential Energy and Potential Difference ... • Capacitance

Cardiac Progenitor Cells and their Therapeutic Application ... · discovery of cardiac resident stem cells in the adult heart and their potential in cardiac repair. Cardiac Progenitor

Resting potential, action potential and electrical ...biophys.med.unideb.hu/.../09/19_action_potential_2012_pdf_16154.pdf · Resting potential, action potential and electrical excitibility

electrical potential and capacitors

Electrical Energy and Capacitance. Potential difference and electrical potential Work and potential energy: Potential energy is a scalar quantity with

DENIS: Solving cardiac electrophysiological simulations ... · understanding of cardiac electrophysiology. In particular, models of the electrical processes in cardiac myocytes can

Cardiovascular System Block Cardiac electrical activity (Physiology )

Electrical Potential Energy

Electrical Potential & Electrical Energy1 CHAPTER 17 Electrical Potential & Electrical Energy Units • Electric Potential Energy and Potential Difference • Relation between Electric

Cardiac action potential

Virtual Heart: Cardiac Simulation for Surgical Training ... · Virtual Heart: Cardiac Simulation for Surgical Training & ... o For the electrical action potential propagation,

Action Potential of Cardiac Muscles (2)

HARDWARE IMPLEMENTATION FOR CARDIAC ELECTRICAL … · HARDWARE IMPLEMENTATION FOR CARDIAC ELECTRICAL EXCITATION AND CONDUCTION USING AN FPGA NUR ATIQAH BINTI ADON A thesis submitted

CARDIAC PHYSIOLOGY - rameshhospitals.com › ... › Cardiac-Physiology.pdf · CARDIAC ACTION POTENTIAL ⚫Normal ventricular Resting membrane potential is -80mv to -90mv. ⚫In contrast

Cardiac Action Potential - Default Store View · action potential in a cardiac autorhythmic muscle cell. • To understand the ionic basis of an action potential in a cardiac contractile

Table of Contents - LITFL · Coronary Circulation Cardiac Cycle Electrical Properties Cardiac Action Potential Cardiac Output Determinants of Cardiac Output Venous Return Myocardial

Heart revolution, cardiac action potential, cardiac electrical activity, ECG Romana Šlamberová, MD PhD Department of Normal, Pathological and Clinical

A model of the ventricular cardiac action potential

Cardiac Repair and Regenerative Potential in the Goldfish