Medical Pharmacology Chapter 43:  Adult Cardiac Procedures

 

Main Cardiovascular Section Menu
Anatomy Section Table of Contents

Site Table of Contents

Previous Page

Cardiac Conduction System

  •  Primary components:

    • Sinoatrial node (SA)

    • Atrioventricular node (AV)

    • Bundle of His

    • Right and left bundle branches

    • Purkinje system

  • Pacemaker nodal cells 

    • P cells or round cells

    • Transitional or T cells

     

    • unknown original source; if this image is in violation of copyright, please inform us.  

     

  • SA nodal location: in the right atrial wall at the junction of the right atrium with the superior vena cava (SVC)

    • above image courtesy of Marquette Electronics

       

  • Connections between the SA  and AV nodes: internodal conduction system composed of:

    1. Anterior (Bachman's bundle)

    2. Middle bundle

    3. Posterior internodal systems

  • Left atrial activation: Bachman's bundle

  • AV nodal  location: in the right atrial floor (near the coronary sinus ostium)

      • image from An Atlas and Practical Guide to Histology, by Dr. Kenneth Chan with technical assistance from Dr. Simon Cool and Mr. Duncan McCardle. The University of Queensland, Department of Anatomical Sciences © 1998   

  • AV nodal anatomy: 3 regions

    •  A-N transitional zone (cells smaller than normal atrial cells)

    •  N region (consisting of  round/P cells (similar to SA nodal cells))

    •  N-H region (transitional area, near the bundle of His)

  • Bundle of His pathway

    1. Traverses the superior edge of the interventricular septum to the septal muscular portion apex

    2. Divides into right and left bundle branches

    3. Branches extend towards the subendocardium along ventricular surfaces

  • Right Bundle of His pathway

    • Emerges in the right ventricular endocardium (near the base of the anterior papillary muscle)

      • One branch passes through the moderator band

      • The second branch traverses over the right ventricular endocardial surface

  • Left Bundle of His pathway

    • Left bundle subdivision:

      • Anterior and posterior fascicles: division shortly after left bundle branch origin (medial fascicle come originating from the left bundle, just after the anterior fascicle)

        • Medial fascicle: activates septal myocardium

  • Right and left bundle branch Fascicle terminations:

    • Subdividing, forming the Purkinje system

      • Left bundle branch fascicle:

        • Initial endocardium contact: interventricular septum, below the aortic valve

      • Right bundle-branch fascicle:

        • Initial  anatomical contact: ventricular subendocardium (near anterior papillary muscle base)

         

  • Summary

    unknown original source; if this image is in violation of copyright, please inform us.  

     

    • Poul-Erik Paulev, M.D., D.Sci Textbook in Medical Physiology And Pathophysiology Essentials and clinical problems Copenhagen Medical Publishers 1999 - 2000 All rights reserved. used with permission

  

Main Cardiovascular Section Menu

Anatomy Section Table of Contents

Site Table of Contents

Previous Page

  • Primary Reference: Lake, C.L. Cardiovascular Anatomy and Physiology, Third edition  (Barash, PG, Cullen, BF, Stoelting, R.K, eds), Lippincott-Raven Publishers, Philadelphia, pp. 805-835, 1997

  • Primary Reference:  Ross, AF, Gomez, MN. and Tinker, JH Anesthesia for Adult Cardiac Procedures in  Principles and Practice of Anesthesiology (Longnecker, D.E., Tinker, J.H. Morgan, Jr., G. E., eds)  Mosby, St. Louis, Mo., pp. 1659-1698, 1998.

  • Primary Reference: Shanewise, JS and Hug, Jr., CC, Anesthesia for Adult Cardiac Surgery, in Anesthesia, 5th edition,vol 2, (Miller, R.D, editor; consulting editors, Cucchiara, RF, Miller, Jr.,ED, Reves, JG, Roizen, MF and Savarese, JJ) Churchill Livingston, a Division of Harcourt Brace and Company, Philadelphia, pp. 1753-1799, 2000.

  • Primary Reference: Wray Roth, DL, Rothstein, P and Thomas, SJ Anesthesia for Cardiac Surgery, in Clinical Anesthesia, third edition  (Barash, PG, Cullen, BF, Stoelting, R.K, eds), Lippincott-Raven Publishers, Philadelphia, pp. 835-865, 1997

Disclaimer

This Web-based pharmacology and disease-based integrated teaching site is based on reference materials, that are believed reliable and consistent with standards accepted at the time of development. Possibility of human error and on-going research and development in medical sciences do not allow assurance that the information contained herein is in every respect accurate or complete. Users should confirm the information contained herein with other sources. This site should only be considered as a teaching aid for undergraduate and graduate biomedical education and is intended only as a teaching site. Information contained here should not be used for patient management and should not be used as a substitute for consultation with practicing medical professionals. Users of this website should check the product information sheet included in the package of any drug they plan to administer to be certain that the information contained in this site is accurate and that changes have not been made in the recommended dose or in the contraindications for administration.  Advertisements that appear on this site are not reviewed for content accuracy and it is the responsibility of users of this website to make individual assessments concerning this information.  Medical or other information  thus obtained should not be used as a substitute for consultation with practicing medical or scientific or other professionals.