Cardiology

Question 1

Cardiac Output =

Answer 1

stroke volume x heart rate

Question 2

Stroke Volume

Answer 2

volume of blood ejected by one ventricle in one cardiac cycle. Normal = 70cc

Question 3

pulse pressure =

Answer 3

systolic - diastolic

Question 4

dichotic notch =

Answer 4

aortic or pulmonary valve closure

Question 5

Ejection Fraction =

Answer 5

Stroke Volume / Diastolic Volume

Normal = 60%

Question 6

Mean Pressures (mmHg) in the systemic CV system:
Aorta
Lg arteries
Arterioles
Capillaries
Vena Cava
R. Atrium

Answer 6

Aorta = 100
Lg Arteries = 100
Arterioles = 50
Capillaries = 20
Vena Cava = 4
Right Atrium = 0-2

Question 7

Mean Pressures (mmHg) in the Pulmonary System:
Pulmonary Artery
Capillaries
Pulmonary Vein
Left Atrium
(Wedge Pressure)

Answer 7

Pulmonary Artery = 15 (sys-25, dia-8)
Capillaries = 10
Pulmonary Vein = 8
Left Atrium = 2-5
(Wedge Pressure)

Question 8

Preload

Answer 8

Left Ventricular Diastolic Volume/Pressure

Question 9

pulse pressure

Answer 9

systolic - diastolic pressure

Question 10

Mean arteriole pressure

Answer 10

diastolic pressure + (1/3) pulse pressure

Question 11

Stroke volume

Answer 11

volume ejected from one ventricle on a single cardiac cycle

Question 12

Cardiac Output

Answer 12

volume of blood pumped by heart per minute

stroke volume X Heart Rate

Question 13

Ejection Fraction =

Answer 13

Stroke volume / end diastolic volume ~60%

Question 14

Mean Pressures (mmHg) in the systemic CV system

Answer 14

Aorta = 100
Lg Arteries = 100
Arterioles = 50
capillaries = 20
Vena cava = 4
Right Atrium = 0-2

Question 15

Mean pressures of the pulmonary system

Answer 15

pulmonary artery = 15
capillaries = 10
pulmonary vein = 8
left atrium = 2-5 (wedge pressure)

Question 16

What are the latent pace makers and their firing rate?

Answer 16

SA Node 70-80
AV Node 40-60
Bundle of HIs 40
Purkinje Fibers 15-20

Question 17

What is a Positive Inotrope?

Give Examples

Answer 17

Increases Contractility and Contraction strength. Sympathetic stimulation -> sympathomimetics: epinephrine, dopamine. Any stimulated Beta 1 receptors which activate G proteins which increases adenyl cyclase which increases cAMP => increased contractility.

Question 18

What is a Negative Inotrope?

Give Examples

Answer 18

Decreases contractility and contraction strength.
Conditions: acidosis, Myocardial Ischemia, cardiomyopathies
Parasympathetic stimulation: Stimulation of muscarinic receptors in the atria, which activates an inhibitory G protein which decreases adenyl cyclase which decreases cAMP, leads to decreased contractility ONLY IN THE ATRIA!!!
Sympatholytic drugs: Beta Blockers
Myocardial depression: anesthetics, Ca2+ channel blockers, toxins(bacterial…septic shock, chemotherapy)