cardio disorder first packet

  1. what are the chambers of the heart
    • right and left atria
    • right and left ventricle
  2. what are the valves of the heart
    • atrioventricular valves which are the papillary muscles and chordae tendinae
    • pulmonic valve
    • aortic valve
  3. myocardium
    • specialized muscle tissue
    • heart muscle
    • cats- 1 billon beats/avg
    • dogs-600 million beats/avg
  4. what are the conduction fibers
    • sinoatrial node-LA (pacemaker)
    • atrioventricular node-between A and V (gathering tissues)
    • purkinje fibers/bundle of his-IV septum (spread out the muscles
  5. what are the major vessels
    • cranial and caudal venae cavae-RA (veins leaves)
    • pulmonary vessel- RV, LA
    • aorta- LV
    • coronary vessels
  6. systolic function
    • cardio output
    • amount of blood going out to body
  7. diastolic function
    relaxation and filling
  8. heart rate
    speed of the beats
  9. heart rhythm
    regularity of the beats
  10. cardiac hypertrophy
    • concentric-pressure overload/wall thickening (gets to stiff to pump, cats)
    • eccentric-volume overload/end diastolic enlargement (making walls thinner losing strength, weak)
  11. systolic function
    • four closely interrelated determinants
    • three determine how much blood is pumped with each beat-stoke volume which is preload, afterload, and contractility
    • cardiac output-SV x HR= L/min
  12. determinants of cardiac output
    • heart rate
    • preload
    • afterload
    • contractility
  13. preload
    • volume of blood in the veins returning to the heart
    • measure of how much the ventricle is stretched at the end of diastole
    • monitoring the central venous pressure, pulmonary capillary wedge pressure, and LV end diastolic diameter
    • increasing any of these parameters causes increased preload and increased stroke volume
  14. increased preload
    • one of the ways the body compensated for reduced CO from heart disease is by small increases in ventricular filling pressure and fluids retention and venoconstriction
    • continued increases in preload due to progressive disease cause CHF
  15. afterload
    • force that resists the flow of blood from the heart-  increased afterload-decreased stroke volume
    • monitoring arterial blood pressure and systemic vascular resistance
  16. afterload and compensation
    • hypotension stimulates vasoconstriction-improved BP, increased afterload and decreased CO
    • poor myocardial function=sensitivity to change in afterload
  17. contractility
    • change in stroke volume independent of changes in preload or afterload
    • affected by calcium levels in myocardial cells-increases calcium causes increased contractility, drugs like digoxin or dobutamine, chemicals like epinephrine
    • monitoring more difficult- shortening fraction which is how much change in wall movement and cardiac output
  18. heart rate and rhythm
    • more of an effect on duration of diastole than duration of systole-alters the normal sequence and duration of atrial and ventricular contraction (dyssynergy)
    • increases in heart rate usually increase CO- tachycardia prevents adequate filling during diastole and bradycardia passes the point where output takes advantage of the increased preload
  19. diastolic function
    • diastolic dysfunction interferes with relaxation and filling
    • diastolic dysfunction alone can cause CHF-important in the heart disease of cats, HCM RCM Hyper T4, ventricles are noncompliant and cannot fill
  20. normal heart rhythm
    • depolarization- P, Q, R, S waves
    • SA node, atrial muscle, AV node, purkinje fibers/IV septum to apex, ventricular muscle back to base
    • repolarization- T wave (getting ready for next beat)
    • normal sinus rhythm-basic normal heart rhythm
    • respiratory sinus arrhythmia- normal variation in dogs, consistent ebb and flow of rate with breathing, changes in vagal tone and thoracic pressures
  21. what are the common symptoms of normal heart rhythm
    • strong possibilities-tachypnea and dyspnea, syncope, weakness and collapse
    • moderate possibilities-coughing dogs, exercise intolerance, abdominal distension
    • at least keep it in mind-weight loss
    • sudden death
  22. physical exam findings
    • heart murmur-disturbed blood flow
    • heart rate abnormality- tachycardia(fast), bradycardia(slow)
    • heart rhythm abnormality
    • dropped pulses
    • respiratory abnormals- change in rate effort and sound
  23. heart murmurs
    • location M,A,P/5,4,3
    • mitral-dogs left 5th IC space, CC junction, cats left 5-6th IC space 1.4 from sternum
    • aortic-dog left 4th IC space above CC junction, cats left  2-3rd space 1/2 to 3/4 from sternum
    • pulmonic-dog left 2-4th IC space sternal border, cats left 2-3rd IC space 1/3 to 1/2 from sternal border
    • tricuspid-dog right 3-4th IC space CC junction, cats right 4-5th IC space 1/4 from the sternum
Card Set
cardio disorder first packet
cardio test first packet