Lecture 9- A Cardiovascular Problme

Question 1

6 parts of the mitral regurgitation case study?

Answer 1

1. Dilated Cardiomyopathy
2. Left Ventricle Dilation
3. Mitral valve incompetence
4. Pressure irregularities
5. Heart sounds
6. Symptom: breathlessness

Question 2

Dilated Cardiomyopathy?

Answer 2

• Cause is often IDIOPATHIC but is likely to be a viral infection
• infected fibres are attacked by lymphocytes and many die or are left weakened and slow to contract
• LV most affected due to high pressure and it dilates
• Fibrous skeleton ring around mitral valve stretches
• Mitral valve flaps no longer meet during systole causing MITRAL REGURGUTATION

Question 3

Left ventricle Dilation?

Answer 3

Lengthening cardiac muscle leads to an increase lumen but 3:1 LV:RV wall thickness remains

Question 4

Mitral Valve Incompetence?

Answer 4

Mitral valve fibrous ring has stretched and the mitral valve cusps no longer meet. During systole, blood regurgitated into the Atrium.

Question 5

Pressure irregularities?

Answer 5

During ventricular contraction there is regurgitation and there is a slight increase in the LA pressure during this phase.

Question 6

Heart Sounds?

Answer 6

There is a heart murmur on the first heart sound heard around the middle of the heart caused by mitral regurgitation.

Question 7

Symptom: Breathlessness

Answer 7

1. Due to MR to maintain CO the LV must pump a greater volume
2. Assuming constant HR the LV filling volume must increase
3. The LA must work harder to do so
4. LA pressure increases
5. Pulmonary Venous pressure increases
6. Pulmonary Capillary pressure increases
7. Pulmonary capillary leakage increase
8. Lungs heavier and wetter
9. Lungs more rigid
10. Breathing requires more muscular work