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Chapter 23 and 24Valvular problems and circulatory shock

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Terms

Prolapse- valve doesn’t close properly

Stenosis- valve has difficulty opening (can have problem with closing too).

Regurgitation- backflow of blood

Auscultation- “listening” to heart sounds….more of them when valves don’t work correctly.

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Dynamics of Streptococcal Damage to Heart Valves Streptococcus

release of M antigen

MM

MM

Heart valve cellwith M antigensattached

• Antibody formed against combination

• Complement damage to heart valves

Mitral #1Aortic #2

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Dynamics of mitral stenosis Stenosis: blood flow from

left atrium to left ventricle decreased

Murmur heard in last part of diastole- why?

Reduced movement of blood.

Enlarged left atrium. Pulmonary edema.

MAP

C.O.

L.ATRIAL VOL. and pressure

RT. VENT. PRESS.

Pulmonary edema

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Mitral valve prolapse

Blood goes back into left atrium

Blowing murmur heard throughout systole - high pitch

MAP and C.O.

MEAN L.ATRIAL VOL.And Pressure Pulmonary edema

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Dynamics of Aortic valve Stenosis Stenosis: Contracting left ventricle

fails to empty adequately (ESV?) SV decreased Left ventricle hypertrophy Leads to increased blood volume

(due to decreased MAP)—kidneys release erythropoietin.

L. Vent pressure and volume

MAP and C.O.

Left atrial pressure Pulmonary edema

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Aortic Regurgitation

Murmur heard during diastole

May have stroke vol. of 300ml with 70ml going to periphery and 230 leaking back

Left ventricular vol and pressure

MAP and net C.O.

Left atrial pressure Pulmonary edema

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Circulatory SHOCK

1. Hypovolemic

2. Vascular

3. Cardiogenic

Circulatory shock-generalized inadequate blood flow to the bodyProgressive vs. non-progressive shock

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Hemorrhage

Diarrhea

Vomiting

Large-scale Fluid Loss

Hypovolemic Shock

• Rapid weak pulse

• Cold, clammy skin

• Decreased CO

• Kidneys respond with angiotensin

• ADH

WHY???

Hint: baroreceptor reflex arc

Burns

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Excessive Allergic Response

Massive Histamine Release

Extreme Vasodilation

Anaphylactic Shock

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Failure to maintain vasomotor tone.

Excess vasodilation.

Neurogenic Shock

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Infection with Gram Negative Bacteria

Bacteria Release Endotoxin

Immune Cells Respond by Releasing Huge Amounts of Vasodilating Nitric Oxide

Excess Vasodilation

Septic Shock

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Inability of the heart to efficiently pump blood.

Cardiogenic Shock

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Hypertension vs. Hypotension

Hypertension MAP is greater than 110mmHg Remember that normal is about

96mmHg Remember how to calculate

MAP? Excess workload, excess

pressure (damage to brain and kidneys)

Treat: diet, exercise, diuretics, Beta-blockers (what does this do to HR?), calcium antagonists (inotropy?), ACE inhibitors

Hypotension CO doesn’t maintain

perfusion Can result from neurogenic

shock Low plasma volume

(excessive sweating, urination, or decreased water intake)

Treat with more salt and water intake.

Note for lab test: be able to calculate PP, MAP, and understand distensibility and hyper/hypotension if given blood pressure values.