Cardiology Flashcards
Cardiac Output =
stroke volume x heart rate
Stroke Volume
volume of blood ejected by one ventricle in one cardiac cycle. Normal = 70cc
pulse pressure =
systolic - diastolic
dichotic notch =
aortic or pulmonary valve closure
Ejection Fraction =
Stroke Volume / Diastolic Volume
Normal = 60%
Mean Pressures (mmHg) in the systemic CV system: Aorta Lg arteries Arterioles Capillaries Vena Cava R. Atrium
Aorta = 100 Lg Arteries = 100 Arterioles = 50 Capillaries = 20 Vena Cava = 4 Right Atrium = 0-2
Mean Pressures (mmHg) in the Pulmonary System: Pulmonary Artery Capillaries Pulmonary Vein Left Atrium (Wedge Pressure)
Pulmonary Artery = 15 (sys-25, dia-8) Capillaries = 10 Pulmonary Vein = 8 Left Atrium = 2-5 (Wedge Pressure)
Preload
Left Ventricular Diastolic Volume/Pressure
pulse pressure
systolic - diastolic pressure
Mean arteriole pressure
diastolic pressure + (1/3) pulse pressure
Stroke volume
volume ejected from one ventricle on a single cardiac cycle
Cardiac Output
volume of blood pumped by heart per minute
stroke volume X Heart Rate
Ejection Fraction =
Stroke volume / end diastolic volume ~60%
Mean Pressures (mmHg) in the systemic CV system
Aorta = 100 Lg Arteries = 100 Arterioles = 50 capillaries = 20 Vena cava = 4 Right Atrium = 0-2
Mean pressures of the pulmonary system
pulmonary artery = 15
capillaries = 10
pulmonary vein = 8
left atrium = 2-5 (wedge pressure)
What are the latent pace makers and their firing rate?
SA Node 70-80
AV Node 40-60
Bundle of HIs 40
Purkinje Fibers 15-20
What is a Positive Inotrope?
Give Examples
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.
What is a Negative Inotrope?
Give Examples
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)