•  Ascending aorta: major branches (arising from the aortic arch)

  • Inominate

    • Divides into right subclavian and right carotid arteries

  • Left carotid

  • Left subclavian

• Rationale for anesthesia providers in learning arterial circulation anatomy:

  • Target sites for direct arterial cannulations

  • Targets that must be avoided for venous cannulations

  • Helping to prevent surgical complications

• Important arterial systems 

  Renal	Coronary	Carotid
  Cerebral	Bronchial	Spinal cord

• Coronary Vasculature

  • Origination: sinuses of Valsalva in the aortic valve (right & left coronary arteries)

    • Left coronary artery: short common or left main component, then dividing into:

      1. left anterior descending

      2. left circumflex

    • Left anterior descending path:

      • downward over the anterior left ventricular wall

      • supplying the interventricular groove by:

        1. diagonal branch

        2. septal perforator branch

    • Consequence of the occlusive disease in the anterior descending blood distribution system -- electrocardiographic manifestations

      •  Ischemic changes in ECG leads  V3-V5

       

• Many Factors may Affect ST, T and U ECG wave forms*

  Ventricular conduction abnormalities (idioventricular rhythms)

  Atrial repolarization (with tachycardia, atrial T waves "may pull down" the beginning of the ST segment)

  Metabolic factors (hyperventilation, hypoglycemia are examples)

  Electrolyte lobe of abnormalities:  (abnormal potassium, magnesium, calcium levels)

  Pharmacology: many drugs including tricyclic antidepressants, quinidine, digoxin (Lanoxin, Lanoxicaps)

  Myocardial disease-- such has ischemia, infarction, myopathy, myocarditis

  Neurological (neurogenic) considerations: trauma, tumor, stroke, hemorrhage are examples

*information courtesy of  Frank G.Yanowitz, M.D. &  The Alan E. Lindsey  ECG Learning Center, used with permission.

• image courtesy of Marquette Electronics

   

• "The "P wave presents atrial activation; the P-R interval is the time from onset of atrial activation to onset of ventricular activation.  The QRS complex represents ventricular activation; the QRS duration is the duration of ventricular activation.  The ST-T wave represents ventricular repolarization.  The QT interval is the duration of ventricular activation and recovery.  The U wave probably represents 'afterdepolarizations' of the ventricles" Courtesy of  Frank G.Yanowitz, M.D. &  The Alan E. Lindsey  ECG Learning Center, used with permission.

   

• Ischemic Heart Disease: ECG manifestations: ST segmental changes

  • ST Segment Depression

    Courtesy of  Frank G. Yanowitz, M.D. &  The Alan E. Lindsey  ECG Learning Center, used with permission. Note that "upsloping" ST depression is not considered an ischemic abnormality.

• Subendocardial ischemia:   Exercise induced or during anginal episode (courtesy of  Frank G.Yanowitz, M.D. &  The Alan E. Lindsey  ECG Learning Center, used with permission)

   

• Differential diagnostic issues in evaluating ST segmental depression

  • Normal variant/artifacts include:

    1. ST-depression secondary to poor skin-electrode contact [pseudo-ST-depression]

    2. Hyperventilation-induced ST segmental depression

    3. Physiological J-junctional depression associated with sinus tachycardia

  •  Ischemic Heart disease

    • "Subendocardial ischemia" (shown above)

    • "Nnon-Q-wave a cardinal infarction"

    • "Reciprocal reciprocal changes in acute Q-wave myocardial infarction (e.g., ST depression in leads I & aVL

  •  ST-segmental changes not due to ischemic heart disease

    •  Digoxin (Lanoxin, Lanoxicaps)/digitoxin (Crystodigin) ECG effects

    •  Hypokalemia

    •  Some cases of mitral valve prolapse

    •  CNS disorders

    •  Secondary ST-changes with certain conduction abnormalities (e.g. right bundle branch blocks, left bundle branch blocks, Wolff-Parkinson-White disorder)

    •  Right ventricular hypertrophy (right precordial leads)

    •  Left ventricular hypertrophy (left precordial leads, I, aVL)

      • Courtesy of  Frank G.Yanowitz, M.D.&  The Alan E. Lindsey  ECG Learning Center, used with permission.

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