Pharm 4

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Cardiogenic Shock: Acute Heart Failure
What is it?
What are the causes?
Cardiogenic shock is the stoppage of the heart.
- Causes:
- Acute MI
- Cardiac Arrhythmias
- Valve Issues
- End-Stage Chronic Heart Failure
Treatment for Cardiogenic Shock: Acute Heart Failure
- Positive Ionotrophic Agents = Increase CO
- 1) Beta-1-Adrengeric Receptors (DOBUTAMINE (selective beta-1-agonist), DOPAMINE (converts both norepinephrine & epinephrine and sustains blood flow to the kidneys through dopamine (DA) receptors)
- 2) Phosphodiesterase 3 (PDE3) Inhibitors: MILRINONE (dihydropyridine); blocking PDE = accumulation of cAMP resulting in positive ionotropic effects
- 3) Muscarinic Rec Antagonists: ATROPINE (blocks effects of the parasympathetic ns on the heart)
Chronic/Congestive Heart Failure...

CO is insufficient to meet the oxygen demands of the body
Chronic/Congestive Heart Failure
Causes (5)
- #1: Coronary Artery Disease / MI
- #2: Hypertension resulting in cardiac hypertrophy
- Others:
- Valve disease/dysfunction
- Cardiomyopathy
- Congenital defects
- Endocarditis/myocarditis
Chronic/Congestive Heart Failure
- 1. Decreased blood distribution & reduced oxygenation of tissue = FATIGUE
- 2. Back-up of blood w/in the venous circulation = "PITTING" EDEMA OF THE LOWER LIMBS
- RIGHT HEART FAILURE DIASTOLIC
- 3. Back-up of blood in the pulmonary circulation = PULMONARY EDEMA
- 4. Accumulation of blood in the ventricles = ENLARGED HEART
- 3 & 4 = LEFT HEART FAILURE/SYSTOLIC
Symptoms of Heart Failure (7)
- Skin cyanotic & clammy
- Upright posture/leaning forward
- Persistent cough
- Rapid Breathing/Fast Heart Rate
- Edema of the lower limbs
- Anxiety/restlessness
Chronic Heart Failure
Treatment Goal?

Increase CO b/c cause is CO is insufficient to meet the oxygen demands of the body
Determinants of CO (4)
- CHAP
- Contractility: force of contraction
- Heart Rate: frequency of contraction
- Afterload: resistance against which the heart has to pump
- Preload: volume of blood in heart prior to contraction
Determinants of CO (4) in detail.
- Contractility: force of contraction
- -calcium dependent (involves ca dependent ca release)
- -regulated by sympathetic ns (beta 1 receptors)
- Heart Rate: frequency of contraction
- -regulated by sympathetic ns (beta 1 receptors)
- -increasing the heart rate in congestive heart failure is counter-productive (produces further mismatch btw filling & contraction)
- Afterload: resistance against which the heart has to pump
- -arterial smooth muscle
- -regulated by sympathetic ns (alpha 1 receptors)
- -regulated by renin-angiotensin system (angiotensin II)
- Preload: volume of blood in the heart prior to contraction
- -return of blood to the heart: VEINS
- -total blood volume: KIDNEY
- -regulated by the renin-angiotensin system (angiotensin II)
Preload: definition/determinants
- Volume of blood in the left ventricle prior to contraction (end diastolic ventricular volume/pressure)
- Determinants:
- 1) Venous return (VEINS)
- 2) Blood volume (KIDNEY)
Frank Starling Law
- CO is determined by preload
- (too much or too little preload = decreased CO)
- congestive hf: accumulation of blood in the heart = increased preload & decreased CO

Author

Anonymous

46595

Card Set

Pharm 4

Description

Pharm 4

Updated

2010-11-01T23:09:46Z

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