cardiac function

Question 1

describe HFpEF and the mechanism

Answer 1

is diastolic

• normal ejection fraction >40%
• mechanism = stiffening ventricles giving impaired relaxation

Question 2

describe the remodelling associated with HFpEF

Answer 2

• concentric (myocytes in parallel)

- increased wall thickness

Question 3

causes and symptoms of HFpEF

Answer 3

• hypertension
• aortic stenosis

symptoms usually w/ exercise

Question 4

factors associated with HFpEF

Answer 4

• older
• female
• diabetes
• AF
• CKD

Question 5

describe HPrEF and the mechanism

Answer 5

systolic

• reduced <40%
• mechanism = reduced force of contraction

Question 6

describe the remodelling associated with HFrEF

Answer 6

• eccentric (myocytes in series)

- reduced wall thickness

Question 7

causes of HFrEF

Answer 7

• MI
• IHD
• valve regurgitation

Question 8

how do you calculate pulse pressure

Answer 8

= systolic pressure - diastolic P

Question 9

how do you calculate MAP

Answer 9

= Pd + 1/3(Ps - Pd)

Question 10

what does a large pulse pressure mean

Answer 10

normal resting = 40 mmHg

large because arteries have reduced compliance therefore are stiff

Question 11

treatment for mitral valve stenosis patients

Answer 11

• percutaneous mitral valvuloplasty

- mitral valve replacement surgery

Question 12

how can mitral stenosis cause atrial arrhythmias

Answer 12

autonomic nervous system remodeled, changing electrical properties

atria dilate → increases re-entrant path lengths & promotes AF

↑ atrial P → stimulates stretch-activated channels

atrial fibrosis → regional slowing of conduction

Question 13

describe the ‘natural’ course of atrial fibrillation

Answer 13

1. paroxysmal AF = comes and goes
2. persistent AF = stays for longer
3. permanent AF = cant be controlled by shock or drugs

is a progression, the more you have it, the more it will come back and change the characteristics of the tissue

Question 14

what treatments are possible for AF

Answer 14

Rhythm control

• amiodarone
• sotalol (B-blocker)

Rate control

• Ca channel blocker
• B-blocker
• digoxin

also an anticoagulant e.g. warfarin

Question 15

explain a systolic murmur and where it is best heard

Answer 15

increased velocity through narrow aortic valve during ejection, this leads to turbulence (reynolds number) and is heard as a murmur

this systolic ejection murmur is heard loudest at the upper right sternal border and radiates to the neck bilaterally (best with diaphragm)

Question 16

why do you get a splitting in the second heart sound and what does it mean if you can’t hear this in a patient with aortic stenosis

Answer 16

splitting because pulmonary valve shuts slighter after the aortic valve.

• aortic component of second heart sound tends to decrease and become softer when aortic stenosis becomes more severe. This is due to increased calcification preventing the valve from ‘snapping’ shut and producing a sharp, loud sound

Question 17

why might you see a larger QRS in a patient with aortic stenosis

Answer 17

• patient has LV hypertrophy (high afterload on LV) therefore more conduction pathways so faster activation

Question 18

explain chest discomfort during exercise in a patient with aortic stenosis

Answer 18

• angina
• increased HR and ventricular wall tension (demand)
• cannot be met by increased coronary perfusion (supply) due to stenosis

demand > supply during exercise

Question 19

treatment possibilities for aortic stenosis

Answer 19

• medical therapies dont stop progression but are useful for symptoms
• aortic valve replacement
  (development of angina, syncope, or dyspnoea are signs for replacement)

Question 20

describe a doppler echocardiography

Answer 20

• see the velocity of BF through the heart
• work out pressure gradient across valves
• work out the valve area