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8 Cards in this Set
- Front
- Back
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What are the three general determinants of myocardial ocygen consumption, or MVO2?
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Afterload (aka Tension development)
Contractility Heart Rate |
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The optimal overlap of thick and thin filaments occurs at a sarcomere length of ______ microns. This physical stretching of ardiac muscle permits optimal overlap of thick and thin filaments, develops tension, and is termed the _______.
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2.2 microns ; preload
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About how many million Americans are CHF patients?
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~ 6 million as of 2002. That's about ~1 per 50 patients!
Mortality from CHF is 20-25% per year! (not good!) |
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List the top 5 etiologies of Congestive Heart Failure.
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1. Coronary Artery Dz presenting a ischemic cardiomyopathy
2. Primary dilated cardiomyopathy ( in VA commonly caused by alcohol, adriamycin, HTN, sarcoid, genetic defects) 3. HTN 4. Valcular heart dz 5. Congenital heart dz |
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In Virginia, what are the most common causes of primary dilated cardiomyopathy (the second most common etiology for CHF)?
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In VA, primary dilated cardiomyopathy is due to:
alcoholism, adriamycin, HTN, sarcoid, genetic defects |
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CHF pathogenesis is said to basically be like a "neuro-hormonal storm". How so? (Hint: short term regulation of arterial pressure and cardiac function are the aorta baroreceptors system and the carotid sinus system, longer loop is the RAA system)
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The aorta baroreceptor and carotid sinus system increase sympathetics when it senses the onset of CHF (decrease of stroke volume). Increase in sympathetics yields increase in NE, increase in HR, increase in contractility.
The RAA system unravels as such: Decrease in renal blood flow is sensed by the juxtaglomerular portion, renin is released from kidney, then angiotensinogen is released from liver. AI is converted to AII via ACE. AII does several things: (1) vasoconstricts (2) drives thirst mech in hypothalamus (3) ADH production in posterior pituitary (4) aldosterone in adrenal cortex Basically, all of this increases intravascular volume and decreases in contractility ensue, the heart becomes signif dilated with signif end diastolic pressure and end diastolic volume. |
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The most signif advances in the field of the treatment fo CHF have been based on the interruption of the neurohoumoral storm. This is done by using pharmacology to decrease __________ and inhibit the neurohumoral storm since once [blank] is decreased, L ventricular afterload is decreased, impedance is decreased and cardiac output is increased. The concept is termed ________________.
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TPR
L ventricular afterload reduction |
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What will the patient's signs and symptoms entail when they present with CHF?
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Fatigue, shortness of breath, dyspnea on exertion.
Resting tachycardia, narrow pulse pressure, possible JVP distention, liver enlargement. Apical impulse might be displaced laterally, and an S3 gallop might be heard. Hallmark diagnostic test of patient presenting with signs and symptoms of heart fialure is an ECHOCARDIOGRAM. This is to quantitate the degree of L ventric dysfunction, chamber size, chamber enlargement, chamber volumes and any regurgitant lesions. Most "bang for buck" diagnostic tool when it comes to CHF. |
