Cardio physiology Flashcards

Question

c-wave JVP

Answer 1

Small peak on approach to x-descent This is tricuspid valve bulging during isovolumetric contraction of ventricles Timed with carotid artery pulse wave

Answer 2

First valley Due to tricuspid valve moving down during ventricular systole.

Answer 3

Second peak Rise in atrial pressure as atria fills prior to opening of tricuspid valve

Answer 4

Second valley Tricuspid valve opens and blood enters ventricle cuasing pressure in atria to drop

Answer 5

ACX VY At CX Vascular Yunit

Answer 6

During isovolumetric contraction - Phase II Compression of the intramyocardial arteries Conditions resulting in low diastolic BP or increased intramyocardial tension during diastole (e.g. an increased end diastolic pressure) may compromise coronary blood flow

Answer 7

Subendocardial muscle where the tension is highest

Answer 8

Diatole when there is an adequate diastolic BP Increased when there is adequate time between beats - i.e. at slower HRs

Answer 9

Raised aortic pressure Aortic valve stenosis Ventricular cavity size, great volume, requires greater tension to achieve same pressure (Laplace's law)

Answer 10

Thermodilution Dye test Doppler USS

Answer 11

= diastolic blood pressure + 1/3 of pulse pressure

Answer 12

Total peripheral resistance Arterial compliance (distensibility - stores elastic energy that means diastolic BP higher) Heart rate

Answer 13

Stroke volume Ejection velocity (without an increase in stroke volume) Diastolic pressure of the preceding pulse Arterial rigidity (arteriosclerosis)

Answer 14

SVR = MAP - mean right atrial pressure / CO Resistance to flow of blood through arterioles. By constricting and dilating, arterioles control the blood flow to capillaries according to local needs.

Answer 15

~ Left atrial pressure Normally 6-12 mmHg >15 --> pulmonary oedema Flotation balloon catheter is passed through the right heart into the pulmonary artery The major advantage of the catheter is that it can be used to measure CO

Answer 16

Alpha + Beta Ionotrope Chronotrope Vassopressor β2-effect at low doses causes vasodilatation in skeletal muscle, lowering SVR. α-vasoconstrictor effect at higher doses increases SVR and myocardial oxygen demands, with adverse effect on cardiac output

Answer 17

α-effect. Vasopressor Indicated in septic shock when hypotension due to peripheral vasodilatation persists despite adequate volume replacement

Answer 18

Exclusively β-effect Ionotrope Chronotrope Vasodilatation in skeletal muscle; therefore reduces SVR Tachycardia limits clinical use Used to increase rate in heart block while awaiting pacing

Answer 19

Low dose causes vessel dilataion of: Renal Cerebral Coronary Splanchnic via D1 and D2 receptors and β1 receptors, resulting in increased cardiac contractility and heart rate High dose stimulates α-receptors, causing vasoconstriction

Answer 20

β1 β2 Inotrope Vasodilator β1 effect increases heart rate and force of contraction Mild β2 effect causes vasodilatation First choice inotrope in cardiogenic shock due to left ventricular dysfunction. Dobutamine and low-dose dopamine in conjunction used in cardiogenic shock to increase BP via increased cardiac contractility and urinary output (UO; via increased renal perfusion)

Answer 21

β2 and D receptors. Inotrope, chronotrope. Peripheral vasodilatation, increased splanchnic blood flow and increased renal perfusion (increased UO)

Answer 22

Nitrates -Vendilatation reducing pre-load Nitroprusside -Arterial vasodilator with short t1/2- -Infusion Hydralazine -Arterial vasodilator -Reduces afterload

Answer 23

Prevent breakdown of cyclic AMP by phosphodiesterase III Ionotropic and vasodilator -little chronoctropic Increased myocardial contractility (increased CO) with reduced PAOP and SVR No significant rise in heart rate or myocardial oxygen consumption