1 Chapter 23 and 24 Valvular problems and circulatory shock

2 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.

3 Dynamics of Streptococcal Damage to Heart Valves Streptococcus  release of M antigen  M M M M  Heart valve cell with M antigens attached Antibody formed against combination  Complement damage to heart valves Mitral #1 Aortic #2

4 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

5 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

6 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

7 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

8 Circulatory SHOCK 1.Hypovolemic 2.Vascular 3.Cardiogenic Circulatory shock- generalized inadequate blood flow to the body Progressive vs. non- progressive shock

9 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

10 Excessive Allergic Response Massive Histamine Release Extreme Vasodilation Anaphylactic Shock

11 Failure to maintain vasomotor tone. Excess vasodilation. Neurogenic Shock

12 Infection with Gram Negative Bacteria Bacteria Release Endotoxin Immune Cells Respond by Releasing Huge Amounts of Vasodilating Nitric Oxide Excess Vasodilation Septic Shock

13 Inability of the heart to efficiently pump blood. Cardiogenic Shock

14 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.