Medical Pharmacology Chapter 43:  Adult Cardiac Procedures

Cardiac Catherization

Coronary Anatomy

Left Coronary Vasculature: Different  Views

Coronary angiography

The left main coronary artery is the most important coronary artery, giving rise to the left anterior descending (to the right of the left main) and circumflex arteries (inferior of the left main)." Attribution:( Cardiovascular Research Institute of Southern California, Ronald P. Karlsberg, M.D., Clinical and Interventional Cardiology, Associate Clinical Professor of Medicine, UCLA School of Medicine, used with permission)

• Extent of coronary vessel disease (stenoses)

  • Worst-case:"triple vessel disease" -- definition of extent of vessel involvement

    •  Left anterior descending artery

    •  Left circumflex artery

    •  Right coronary artery

  • Definition: "complete occlusion with collateral filling" = normal blood supply lost; however, some perfusion remains through collateral vessels from neighboring arteries

  • Most serious condition: "left main" coronary stenosis: 

    •  Reason: left main coronary (which bifurcates into left anterior descending and left circumflex components) supplies most of the left ventricle

      •  Occlusion of left main coronary vessels would cause significant ventricular dysfunction, secondary to ischemia (note that the right coronary arteries supplies some collateral flow to regions of the anterior descending and circumflex vessel)

      •  Under some circumstances the left main artery may be open, but occlusion might exist in branches, such as circumflex and left anterior descending and right coronary: 

        •  This condition can be described as "left main equivalent", meaning that although the left main  artery is normal, significant ischemia may occur with further coronary blood flow reduction

  • Very advanced coronary artery disease may be present in the absence of abnormal indices of ventricular performance

    •  Angina on exertion may exist -- with no history of myocardial infarction

    •  Poor ventricular performance may be consistent with:

      1. Previous myocardial infarction 

      2. Ongoing myocardial infarction

    • LAD: subtotal obstruction; circumflex, severe disease. Occluded right coronary -- patient managed with coronary artery bypass surgery.  Attribution:  (Cardiovascular Research Institute of Southern California, Ronald P. Karlsberg, M.D., Clinical and Interventional Cardiology, Associate Clinical Professor of Medicine, UCLA School of Medicine, used with permission)

       

• Right vs. Left coronary Artery Dominance:

  •  Right dominance: Frequency = 85%; right coronary artery continues onto the posterior cardiac wall as a posterior descending vessel

    •  Posterior descending coronary supplies:

      1. Posterior and

      2. Diaphragmatic part of the interventricular septum

    •  Arteriovenous (AV) nodal artery is right from the right coronary artery

  •   Left dominance: Frequency = 8% circumflex coronary artery traverses inferiorly down the back of the heart (major posterior descending coronary artery) (remaining 7%, indeterminate by angiographic analysis)

  •  Relevance to the anesthesia provider:

    1. Right-dominant patient: Air bubbles from the aorta most often enter the right coronary artery (right coronary arises from "anterior" [i.e. uppermost part in the supine intraoperative room patient position] in a right-dominant system, air can enter the AV nodal artery, producing heart block.

    2. Left-dominant patient with left circumflex  and/or left main vessel disease may experience:

       1.  Poor protection my cardioplegia

       2.  Marginal perfusion of the left ventricular posterior wall

       3.  Difficulty in separation from bypass perfusion system

• Coronary angiographic standards and limitations in assessment of the degree of stenosis:

  • Gold Standard

  • Limited use in predicting physiological significance of lesions

  • Difficulty in assessing lesion asymmetry with single radiographic projection

  • Significant interobserver variability

• 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

• ⁴Zanger, D.R, Solomon, A.J., Gersh, BJ, Contemporary Management of Angina: Part I.  Risk Assessment American  Family Physician, December 1, 1999

• ⁵Kay, GL, Sun, GW, Aoki, A, et al: Influence of ejection fraction on hospital mortality, morbidity, and costs for CABG patients, Ann. Thorac Surg 60 (6): 1640-1650, 1995 (2nd sourced from  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. 201-218, 1998)