Heart Disease Etiology, Symptoms, Treatment

Systolic or Diastolic
1. Systolic
  1. Decreased ability of the heart to pump out blood
    1. Due to weakening of the wall of the ventricle (dilated)
      1. Due to cell death
        Resulting in a decreased ejection fraction
        Which is due to decreased force of contraction and decreased Stroke Volume
        Remember that EF=SV/LVEDV
        So... decreased SV means a decreased EF
  2. Caused by...
    1. Heart muscle disease (Cardiomyopathy) of unknown cause
    2. Decreased blood supply to heart muscle due to CAD resulting in heart cell death
    3. Valvular disease
      1. Regurgitation at AV valves
        R/I increased work, increased O2 requirement, cell death
      2. or Stenosis of semilunar valves
        Ditto. Different problem, same result
    4. Arrhythmia
      1. Ditto. There's just not enough O2 available to allow for extra work
    5. Ventricular Dilation and altered cardiac muscle contractility or
2. Diastolic
  1. Decreased ability of the heart to fill
    1. Due to hypertrophy of the wall of the ventricle
      1. Due to increased after load
        Resulting in a "normal" ejection fraction
        But a decrease in blood pumped out of the heart
        Due to a lack of space within the ventricle
        Remember that EF=SV/LVEDV
        So... decreased filling but the same percentage pumps out
        Means a "normal" EF
  2. Caused by...
    1. An increase in after load, as is found in Hypertension
    2. Aortic Valve Stenosis
    3. Cardiomyopathy
      1. Hypertrophic
      2. or Restrictive
      3. Disease leads to decreased blood supply
        Which leads to hypertrophy of mm and increased work
        Which leads to an increased demand for oxygen
        Which leads to cell death, scar tissue and restriction
        Which leads to a decreased blood supply
        and so on...
Can be left heart failure, or right, or both
1. Left Heart Failure
  1. Blood backs up into the lungs
    1. and from there into the right ventricle and so on
  2. CHF
  3. Symptoms
    1. Forward Failure
      1. Fatigue
      2. Decreased urine production
      3. Palpitations
    2. Backward Failure
      1. Lung Congestion
        Difficulty breathing
        and pink, foamy mucus
      2. Orthopnea
      3. Weight Gain
2. Right Heart Failure
  1. Blood backs up into the body - usually the legs
  2. Symptoms
    1. Forward Failure
      1. Fatigue due to CO2 levels
      2. Palpitations
    2. Backward Failure
      1. LE Congestion
      2. Jugular Vein Distension
      3. Weight Gain
      4. Increased urination, especially at night
Compensation
1. Is meant to increase Cardiac Output
  1. Remember CO=SVxHR
    1. normally about 5L/minute
  2. in order to meet the demands of the body for more oxygen than it's getting
    1. Increase SV
      1. by activating the Sympathetic Nervous System
        which eventually exhausts the heart's response to it
      2. or Increase Preload
        Remember Starling's Law
        by activating the ADH System
        which causes the body to retain fluids
        which increases the work of heart, which demands more oxygen, which is unavailable, so cells die
      3. or via Hypertrophy of muscle
        Ditto - cell death
    2. or Increase HR
      1. by activating the Sympathetic Nervous System
        Ditto
2. Which eventually leads to decompensation
First, treat with exercise, dietary changes, and HTN Meds
1. Angiotensin Converting Enzyme (ACE) Inhibitors
  1. Vasodilators
    1. Decrease Afterload
2. Beta-blockers
  1. Block the activation of beta receptors
    1. Decreasing heart's response to Sympathetic Nervous System
3. Hydrazine and Nitrates
  1. Vasodilators for either arteries or veins
    1. Decrease Afterload
    2. Decrease preload
4. Meant to either make the heart more efficient
  1. or to decrease the likelihood of structural changes
Later, treat the symptoms of congestion with diuretics (i.e. Aldosterone Inhibitors)
1. Decreasing fluid build-up in lungs and BP
2. Calcium Channel Blockers for Diastolic Failure
  1. Decreasing smooth muscle contraction which decreases BP
  2. Decreasing Heart Muscle Contraction
    1. Which allows the heart to fill
FINALLY, for end-stage treatment
1. Ventricle Assist Device
  1. Bypasses the Ventricle and pumps blood to the body
2. Pacemaker or Defibrillator
3. Stents to widen arteries
4. or Coronary Artery Bypass
5. Heart Transplantation

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	Creado por Laurie Schroder hace más de 8 años