Cardiac Function II

Question 1

Cor pulmonale

Answer 1

right sided heart failure, enragement of the right ventricle due to high blood pressure in the lungs, usually caused by chronic lung disease

Question 2

Pulmonary hypertension my be caused by?

Answer 2

• Loss of capillary beds (e.g. due to bullous changes in COPD or thrombosis in pulmonary embolism)
• Vasoconstriction caused by hypoxia, hypercapnia, or both
• Increased alveolar pressure (e.g. in COPD during mechanical ventilation)
• Medial hypertrophy in arterioles (response to pulmonary hypertension due to other mechanisms)

Question 3

What does smoking do to the lungs long term?

Answer 3

Causes obstructive airway disease, loss of elastin etc, all of which inc work of breathing

Question 4

What is the 2nd heart sound related to

Answer 4

Normally split, splitting increases during inspiration (reduced intrathoracic pressures during inspiration = more fluid into right side of heart so emptying of right heart takes a bit longer)and decreases during expiration

In order for the ventricle to eject blood against a higher pressure than used too it takes longer, so splitting might be increased, and because inc pressure in the pulmonary artery, when the valve closes the sound is a lot more accentuated than normal

Question 5

Explain back pressure in right sided heart failure

Answer 5

Neck vein distension (raised JVP), hepatomegaly and peripheral oedema due to elevated systemic venous pressures as a result of right heart dysfunction

Question 6

What may occur in the heart late in disease as a result of RV dilatation

Answer 6

tricuspid regurgitation

Question 7

Cor pulmonale, what might you see on an ECG

Answer 7

Right axis deviation

increase in right ventricle size?

Question 8

What does COPD do to ECG signals

Answer 8

expanded chest may reduced ECG potentials

Question 9

Cor pulmonale why the intraventricular septum displaced to the left during diastolie?

Answer 9

During diastole pressure is higher on the right than on the left, because you have back pressure on the right side of the heart through the periphery which turns out to be filling pressure when the heart is relaxed

Question 10

Childhood rheumatic fever and mitral stenosis

Answer 10

yes.
Thickening of valve leaflets with fibrous obliteration
May be calcium deposition in the leaflets, chord and the annulus with commissural and chordal fusion
Eventually get funnel shaped metal valve with fish - mouth orifice

Question 11

mitral valve stenosis - Sob and fatigue with exercise

Answer 11

high pressures in the lungs, pulmonary vascular engorgement, reduced lung complaince and increased work of breathing
Lack of atrial contraction –> reduced ventricular pre load
at rest may be fine but during exercise, heart unable to increase output sufficiently to get increased demand

Question 12

Ortner’s syndrome

Answer 12

vocal cord paralysis

impression of left recurrent laryngeal nerve by enlarged LA or pulmonary artery

Question 13

Severe mitral valve stenosis, explain attenuated first heart sound

Answer 13

Greater excursion of leaflets during closure, since elevated LA pressure has kept the leaflets relatively wide apart
except when valve gets super calcified and hardly moves, sound gets soft again,

Question 14

mitral valve stenosis: explain the opening snap

Answer 14

Under a high pressure gradient the abnormal valves billow into the LV and are rapidly arrested by the chordae, causing sudden vibrations

No heard when significantly calcified

Question 15

mitral stenosis: explain prolonged diastolic murmur

Answer 15

turbulent blood flow through narrowed valve opening, best heard over the apex of the heart with the bell of the stethoscope

Question 16

Treatments for mitral valve stenosis

Answer 16

percutaneous mitral valvuloplasty
Mitral valve replacement surgery

Mechanical valve clots so have to take anticoagulants, if still of childbearing age, not ideal.

Question 17

Why are patients with mitral stenosis typically at risk of developing atrial arrhythmas such as atrial fib

Answer 17

structural remodelling of left atrium
Manifested by LA distention and hypertrophy as well as extensive diffuse fibrosis
LA enlargement increases atrial electrical path lengths and the distention also increases the probability of ectopic activation in the sleves in the base of the pulmonary veins where they enter the roof of the LA
The inflammation and fibrosis contribute to tortuous conduction and activation delays to facilitate unstable electrical activity
- regional varying of ANS remodelling, changing excitability of some regions of the atria
said changes markedly increase the probability of re entrant arrhythmia in atria, and in extreme cases lead to AF

Question 18

What treatments are possible for the atrial fibrillation

Answer 18

Rate control

• Ca channel blocker
• Beta-blocker
• Digoxin

Rhythm control

• amiodarone
• sotalol- nonspecific beta blocker
• dc conversion
• ablation therapy

Question 19

What other drugs are important in Atrial Fib and why?

Answer 19

Anticoagulant - risk of stroke, thrombi from the left atria and left atrial appendage

Dabigatran > warfarin (less blood tests and interactions with other drugs and food)

Question 20

aortic stenosis risk factors

Answer 20

hypertension, smoking, smile sex, age, increased LDL, diabetes

Question 21

pathogenesis following aortic stenosis

Answer 21

LV must generate higher pressure to eject blood
Leads to development of LV hypertrophy (concentric) impaired diastolic function (HFpEF) over time this can progress to LV dilatation, wall thinning and systolic failure (HFrEF)

Question 22

Where would you expect to hear aortic stenosis and what characteristics?

Answer 22

systolic, ‘crescendo, decrescendo’ pattern. right parasternal edge 2nd ribspace, radiating to the neck bilaterally
Feel for a thrill in the sternal notch

Question 23

Explain lack of splitting of second heart sound

Answer 23

Aortic component of 2nd heart sound tends to become decreased and softer as the aortic stenosis becomes more severe.
This is a result of the increasing calcification of the valve preventing it from “snapping” shut, producing a sharp, loud sound.

Question 24

Aortic stenosis - ECG findings

Answer 24

left axis deviation

enlarged QRS complexes

Question 25

aortic stenosis, cause of mild chest discomfort during exercise?

Answer 25

Angina
Increased LV muscle mass, without soncomitatnt increase in vasculature, reduces coronary reserve
Increased HR and ventricular wall tension during exercise (demand) cannot be met but increased coronary perfusion (supply) because of aortic stenosis.
Coronary ostia are outside the aortic valve where pressure is low - increased flow rate here will also reduce pressure.

Question 26

Aortic stenosis - heart failure basis

Answer 26

Initially thick, stiffened ventricle, HFpEF
over time
wall thickens progressive ischaemia to tissue, chamber dilates and get HFrEF

Question 27

Speculate on long term treatment

Answer 27

balloon valvuloplasty just palliative procedure, valves still thick and calcified

Definitive treatment is aortic valve replacement
Decision on when to treat is based on severity:
- Primarily based on transaortic pressure gradient (using doppler US) and blood flow velocity across the aortic valve