Heart 2 Flashcards

1
Q

Cardiac output = ?

A

“CO = Stroke volume (SV) x Heart rate (HR)

  • SV = end diastolic volume (EDV) - end systolic volume (ESV)”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mean arterial pressure (MAP) =?

A

“MAP = CO x total peripheral resistance (TPR)
or
MAP = 2/3 diastolic pressure + 1/3 systolic pressure”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Pulse pressure = ?

A

“pulse pressure = systolic pressure - diastolic pressure

  • it is proportional to SV, inversely proportional to arterial compliance”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

during the early stages of exercise, CO is maintained by? What about late stages of exercise?

A

“early stages: ↑ HR and ↑SV

late stages: ↑ HR only (SV plateaus)”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Stroke volume is increased by?

A
"SV CAP 
↑ Contractility (exerise, anxiety, pregnancy) 
↓Afterload 
↑ Preload 
(remember SV = EDV - ESV)"
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Contractility increases with?

A

“Catecholamines (↑ activity of Ca2+ pump in sarc retic)
↑ intracellular Ca2+
↓extracellular Na+, or ↑ intracellular Na+
Digitalis (blocks Na+/K+ pump, ↓Na+/Ca2+ exchanger activity)
(remember SV = EDV - ESV)”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Contractility decreases with ?

A

β-blockade (↓ cAMP), Heart failure with systolic dysfunction, acidosis, hypoxia, non-dihydropyridine Ca2+ channel blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

↑ myoCARDial O2 demand is ↑ by?

A

“↑ Contractility
↑ Afterload (proportional to arterial pressure)
↑heart Rate
↑ Diameter of ventricle (↑ wall tension)”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Preload is approximated by? What two things does it depend on?

A

Preload approximated by ventricular EDV; depends on venous tone and circulating blood volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Afterload is approximated by ?

A

“afterload approximated by MAP

↑ Afterload → ↑ pressure → ↑ wall tension per Laplace’s law”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What ↓ preload? What ↓ afterload?

A

vEnodilators (nitroglycerin) ↓ prEload, vAsodilators (hydralazine) ↓ Afterload, ACE inhibitors and ARBs ↓ both preload and afterload.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

LV compensates for ↑ afterload by hypertrophy in order to do what?

A

↓ wall tension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly