5. Seminar: Heart Failure

Question 1

why would BP and HR increase in a pt having CHF (SOB after days of fatigue, edema, orthopnea)?

Answer 1

sympathetic stimulation –> vasoconstriction and cardiac activation.

Question 2

pt having CHF: why would his skin be cool and clammy?

Answer 2

because of the alpha-1 adrenergic component of the sympathetic response, leads to reduced blood flow to the skin.

Question 3

in addition to causing cutaneous vasoconstriction, the sympathetic response can do what?

Answer 3

stimulate sweat glands. –> cool and clammy.

Question 4

what is one way in which heart failure can cause dyspnea?

Answer 4

fluid transudating into interstitial space can cause lung stiffness (incr work of breathing) & cause arterial hypoxia (because the low solubility of 02 in aqueous solutions impairs 02 diffusion from alveoli to blood in the pulm capillaries).

Question 5

what are rales?

Answer 5

crackles heard when air entering fluid-filled small bronchi causes these structures to open with a pop.

Question 6

why would rales sounds be most in the bases of the lungs?

Answer 6

due to gravity’s effects on the fluid in the lungs.

Question 7

how would a low EF be connected to a hypertrophied heart?

Answer 7

EF = SV/EDV. if you increase EDV (by hypertrophied heart) but leave SV the same, then EF will decrease.

Question 8

what does a loud P2 heart sound tell you?

Answer 8

that the pulmonary artery pressure is high.

Question 9

what are ascites/what causes them?

Answer 9

high systemic venous pressure causes fluid to transudate from capillaries into peritoneal cavity.

Question 10

why might a liver be large and tender with high venous pressure?

Answer 10

engorged by blood

Question 11

what is a great description of edema?

Answer 11

fluid transudates out of capillaries into tissues more rapidly than it can be removed from lymphatics.

Question 12

what mechanisms can cause arterial hypoxia in severe heart failure?

Answer 12

weakness of skel muscles used in resp, also fluid accumulation in interstitium which decr 02 transport to capillaries. this fluid accumulation can be due to Lsided heart failure.

Question 13

what kind of heart failure does a uniformly dilated left ventricle and low EF suggest?

Answer 13

systolic failure. occurs in ischemic and dilated cardiomyopathies, and with volume overload due to leaky aortic or mitral valve.

Question 14

concentric hypertrophy: characterized by what change to LV, what kind of EF, and what kind of valve problems?

Answer 14

thick walled LV, normal EF, and stenotic valves

Question 15

eccentric hypertrophy: characterized by what change to LV, what kind of EF, and what kind of valve problems?

Answer 15

thin walled distended LV, low EF, and leaky or regurg valves.

Question 16

what is the most impt cause of systolic heart failure in dev countries?

Answer 16

MCI.

Question 17

what would be a typical finding to indicate backwards failure?

Answer 17

increased pressure in RA, RV, Pulm artery, LA (via wedge pressure)

Question 18

what would be a typical finding to indicate forward failure?

Answer 18

low CO.

Question 19

with high pulmonary vascular resistance, what compensation will take place to help RV eject blood against the high pulm artery pressure?

Answer 19

a high pulm vasc resistance will yield increased RV afterload, which then increases RV end-diastolic pressure and volume, and incr ability of the RV to ultimately eject.

Question 20

how can proliferation damage the myocardium in patients with systolic heart failure?

Answer 20

causing cardiac myocytes to elongate, and by stimulating apoptosis.

Question 21

why is cardiac myocyte death such a disaster?

Answer 21

because these terminally-differentiated cells have little or no capacity to divide. when they die, few are replaced.