Diseases Quiz 3 Flashcards
Circulatory Shock
Generalized
Severe reduction in blood supply to the body tissues –> metabolic needs are not met.
Arterial pressure usually low (even w/ compensatory mechanisms)
Severe shock –> inadequate brain blood flow leads to loss of consciousness w/ sudden onset. (syncope)
Sx: pallor, cold clammy skin, rapid HR, muscle weakness, venous constriction
Additional Compensatory Processes:
- Rapid, shallow breathing –> promotes VR via action of respiratory pump
- Increased renin release –> increased TPR via formation of angiotensin II
- Increased circulating levels of ADH –> increases TPR
- Increased circulating levels of epinephrine
- Reduced capillary hydrostatic pressure resulting from intense arteriolar constriction –> reabsorption
- Increased glycogenolysis in the liver (induced by epi and norepinephrine)
Progressive Shock: general CV situation progressively degenerates
Irreversible Shock: no intervention can halt the ultimate collapse of the CV system –> death
Cardiogenic shock
Cardiac pumping compromised –> decreased CO
Ex: severe arrhythmias, abrupt mitral malfunction, MI, coronary occlusions
Patient’s skin cold and clammy (intense vasoconstriction). Oxygen content high on swan-ganz (blood is rushing past tissues)
Hypovolemic shock
Depletion of body fluids –> decreased BV –> reduced cardiac filling –> reduced SV
Ex: hemorrhage (>20% of BV), fluid loss from severe burns, chronic diarrhea, prolonged vomiting
Patient’s skin cold and clammy (intense vasoconstriction). Oxygen content high on swan-ganz (blood is rushing past tissues)
Anaphylactic shock
Severe allergic reaction –> relase of histamine, prostaglandins, leukotrienes, bradykinin –> increased arteriolar vasodilation –> increased microvascular perm –> loss of venous tone –> decreased TPR and CO
Patient’s skin will be warm and pink (intense vasodilation). Oxygen content low on swan-ganz
Septic Shock
Severe vasodilation due to release of substances from infectious agenst
i.e. LPS –> NO synthase increased –> vasodilation
Patient’s skin will be warm and pink (intense vasodilation). Oxygen content low on swan-ganz
Neurogenic shock
Loss of vascular tone due to inhibition of normal tonic activity of sympathetic vasoconstictor nerves
Ex: deep anesthesia, reflex response to deep pain associated w/ trauma, vasovagal syncope.
Acute Coronary Syndrome
Unstable angina vs. MI
Caused by rupture of unstable plaque w/ partial or complete lumen occlusion by aggregated platelets/thrombosis.
MI
Complete thrombotic occlusion of an atherosclerotic coronary artery or hypotensive event superimposed on a partially occuled CA
> 30 min of complete ischemia = myocardial death
transmural infarciton: more likely STEMI
Extent of infarction depends on collateral circulation.
ACUTE sequelae:
Severe /unrelenting angina, acute congestive heart failure (CHF) with dyspnea (pulmonary edema/oxygen desaturation) cardiogenic shock, dysrhythmias, sudden death
Subacute sequale (several days - 2 weeks): Mural thrombosis/risk of embolism, left ventricular rupture = free wall, septal, or papillary muscle: fatal hemopericardium, acute VSD, or acutely flail/regurgitant mitral valve; peri-infarct pericarditis.
Chronic sequelae:
Left ventricular aneurysm; if infarct large enough or multiple infarcts = chronic CHF: LV ejection fraction usually
Cor pulmonale
Pure right sided hypertensive heart disease.
due to chronically increased pulmonary artery pressure from: -COPD
- interstitial fibrosing diseases. -Chronic hypoxia causing vasoconstriction (i.e. sleep apnea)
- Pulmonary vascular disease (primary pulmonary HTN or chronic recurrent thromboemboli)
Calcified Aortic Stenosis
Leading cause of valve replacement surgery along w/ mitral valve prolapse.
Aging related atherosclerosis of aortic valve cusps w/ secondary nodular calcification producing severe ( age 65): association with CAD
Sx: angina, dyspnea, fatigue, syncope, hypertrophied LV, eventual CHF.
Rx: Aortic valve replacement +/- coronary re-vascularization
Cardiomyopathy
Intrinsic myocardial disease NOT associated w/ ischemic, valvular, hypertensive, or structural congenital heart disease.
Clinically divided into dilated, hypertrophic, or restrictive.
Causes include: genetic, myocarditis (i.e. viral), drug effects (alcohol, chemo), hemochromatosisi, and amyloidosis
Tamponade
Increased pericardial sac fluid critically compresses the heart
Many causes:
- effusion: from infx or non-infectious disease (CHF, neoplastic infiltrate, uremia)
- hemopaericardium: (ruptured MI, retrograde rupture of aortic dissection, or penetrating chest trauma)
Constrictive pericarditis:
Progressive pericardial space fibrosis which critically compresses the heart
Rhabdomyoma
Tumor found in children, usually w/ tuberous sclerosis.
Myxoma
Most common adult cardiac tumor. Usually left atrium.
