Co

Front 1

1. Law that states the force of ejection is proportional to the length of the m. fibers?

skeletal m. operate at optimal sarcomere length, cardiac m. operates at shorter than optimal length -- this allows the hrt to contract more in response to increased stretch - basis for 1

Back 1

1. Frank Starling law

Front 2

1. Increased intracellular calcium does what to contractility and ESV?
2. If 1 occurs and EDV does not change, what value increases?

Back 2

1. Increases contractility thereby decreasing ESV
2. SV

Front 3

1. End systolic pressure is determined by what?
2. What will happen as 1 increases?
3. changes in 1 effect SV by changing what?

Back 3

1. Aortic pressure
2. ESV will occur at a higher volume (more blood left in the hrt)
3. ESV

Front 4

1. A decrease in diastolic compliance following a MI does what to the EDV?
2. Term for a m. shortening against an increasing load?
3. Why is ventricle contraction not isotonic?

Back 4

1. Decreases the EDV - this thus decreases the SV
2. Auxotonic contraction
3. the afterload is not constant

**relevant b/c as volume in the ventricle decreases, ability to develop pressure falls and leads to valve closure

Front 5

1. An increase in contractility does what to isometric force and velocity of contraction?
2. What is assessed by measuring the rate at which ventricular P rises during the isovolumetric period of contraction

Back 5

1. INcreases both
2. Velocity of shortening dP/dt --> measurement is obtained by placing a conductance catheter in teh ventricle and measuring end-systolic volume
**up venous pressure can also increase dP/dt

Front 6

1. What is the most accurate measurement for determining cardiac fxn? limited clinical application due to invasiveness?
Pulse doppler filling waves
2. Passive filling of LV
3. Atrial contraction

Back 6

1. A conductance catheter - can inject saline into ventricle and see response to increased vol
2. E
3. A

Front 7

1. A dagger shaped echocardiograph is indicative of what?
2. What is the work expended to move blood, 10% of total work, 1% is KE to blood pumped, = ventricular pressure x stroke volume
3. 90% of energy used, mostly in isovolumic contraction, increased in hrt dilation = time in isovol contraction x ventric wall tension

Back 7

1. ventricle having trouble contracting
2. External physical work - EW
3. Internal work - IW

Front 8

Pressures in:
1. Rt atria (lt atria)
2. Rt ventricel (lt ventricle)
3. pulmonic a. (aorta)

Back 8

1. 2-10 (3-15)
2. 1-8, 15-30 (3-12, 100-140)
3. 5-12, 15-30; (60-90, 100-140)

Front 9

1. avg hrt rate
2. SV
3. Ventricular output
4. Goal of heterometric regulation?

Back 9

1. 75 bpm
2. 70 mL
3. 5 L/min
4. Maintain CO

Front 10

1. What are the 2 broad mech. of stroke volume regulation

+inotrope = + increase in CO

Back 10

1. Length dependent (heterometric; intrinsic - increase sarcomere length) vs length independent (homeometric; contractility; extrinsic - increase force at a give sarcomere length - + inotropy)

Front 11

1. 2 methods of increasing homeometric force?
2. Stretched muscle generates more force (heterometric), what does it take to increase Vmax?
3. What does digitalis do?

Back 11

1. activate more troponin C, phosphorylate myosin light chain kinase
2. add an inotropic agent -> generates more force
3. Increases force of contraction which helps the hrt compensate for increased volume better

Front 12

1. Diastolic heart failure leads to what type of hrt
2. Systolic hrt failure leads to what type of hrt
3. Term for the rate of flow entering the rt atrium?
4. level at which the hrt can no longer match venous return?

Back 12

1. Hypertrophied
2. Dilated
3. Venous return, at SS = CO
4. 9 L/min

Front 13

Pa = arterial pressure
1. If Pa & HR are held constant, how will EDV, SV, CO respond to increased venous return (VR)?
2. If HR & VR are held constant, how will SV, CO, and EDV respond to increased Pa?
3. If Pa & VR are constant how will CO, EDV and SV respond to increased HR?

Back 13

1. increase EDV, SV, CO
2. SV, CO will initially fall due to increased Pa (afterload) but EDV increases which causes an increase in SV & CO
3. CO initially increases but EDV and SV decrease until CO is unchanged from orig due to higher HR

Front 14

1. What occurs due to decreased LV compliance, associated w/ cardiac hypertrophy?
2. What is the goal of heterometric regulation?

Back 14

1. Diastolic hrt failure - hrt can't fill right
2. maintenance of CO

Front 15

1. What maintains the balance between lt and rt hrts on a beat to beat basis & modulates output of hrt in accordance w/ the rate at which blood is returning from the organs
2. A shift upward on a cardiac fxn curve is indicative of what?

Back 15

1. Heterometric regulation
2. increased contraction

Front 16

1. If HR and VR are constant, how will SV, CO and EDV respond to increased Pa?
2. If HR, Pa, VR are held constant, how will SV, CO and EDV responds to Norepinephrine?
3. If HR, Pa, EDV are constant, how will SV and CO respond to NE?

Back 16

1. Pa -> increase in afterload. Decreases the SV and CO. EDV (preload) increases until SV & CO return to normal
2. SV and CO increase until EDV is depleted then they match pre epi levels
3. Both increase

Front 17

1. What is the only hrt regulatory mech present in transplant patients?
2. Which are imp in non transplant pts?
3. Mech. involved in mild exercise?
4. Intense?

Back 17

1. Heterometric - b/c no sympathetic innervation (so no homeometric effect
2. Heterometric and homeometric
3. mild = homeometric
4. intense - get both

Front 18

1. What results in reduced SV due to increased afterload, increased ESV, compensatory increase in EDV and pressure
2. What results in reduced EDV; reduced SV; reduced afterload which enables ESV to decrease slightly; fusion of E and A waves on echo

Back 18

1. Aortic stenosis
2. Mitral stenosis

Front 19

1. What prevents true phase of isovolumic relaxation and contraction; greatly increased EDV;
2. Prevents true pahse of isovolumic contraction; decreased ESV; prevents true phase of isovolumic relaxation; increase in EDV

Back 19

1. Aortic regurgitation
2. mitral regurg