49&50: Cardiac Function 2

Question 1

Define cor pulmonale

Answer 1

Pulmonary and arterial hypertension resulting from disease affecting lung structure/function. It leads to RV enlargement and in time RHS heart failure.

Question 2

What are causes of pulmonary hypertension?

Answer 2

• Loss of capillary beds
• Vasoconstriction caused by hypoxia, hypercapnia, both
• Increased alveolar pressure
• Medical hypertrophy in arterioles

Question 3

Why is the second heart sound split enhanced with inspiration?

Answer 3

Reduced intrathoracic pressures lead to increased right heart filling, delaying pulmonary closure

Question 4

Why is the IV septum displaced leftward during diastole in a patient with pulmonary hypertension

Answer 4

• RV diastolic pressures increased

- Pressure gradient across IV septum during diastole pushes it into LV cavity

Question 5

Why does a patient experience SOB with mitral valve stenosis?

Answer 5

• Inc. back pressure in pulmonary vasculature

(engorgement)

Question 6

Why is 1st HS enhanced in patients with mitral stenosis?

Answer 6

Mobile but stiff mitral leaflets open more due to elevated pressure

Question 7

What causes an opening snap in mitral stenosis?

Answer 7

• High pressure gradient

- Abnormal valves billow into LV and are rapidly arrested by chordae tendineae, causing vibrations

Question 8

Why are patients with mitral stenosis at risk of atrial arrhythmia?

Answer 8

• LA enlargement inc. path length and distention, inc. probability of ectopic activation
• Inflammation and fibrosis cause activation delays, facilitate unstable electrical activity
• Regionally varying ANS remodelling

Question 9

What is the spectrum of AF?

Answer 9

• Paroxysomal
• Persistent
• Permanent

Question 10

Explain the pathophysiology of aortic stenosis

Answer 10

• Endothelial cell damage from mechanical stress
• Inflammation of deposition of LDL cholesterol and lipoproteins occurs
• Valve thickens and becomes calcified

Question 11

Why does a patient with aortic stenosis feel dizzy when exercising

Answer 11

• Vasodilation in skeletal muscle
• Heart cannot deliver extra flow rate
• Overall fall in MAP causes reduced brain perfusion

Question 12

What electrical abnormality do you need to be aware of in a patient with aortic stenosis?

Answer 12

• LBBB

- Calcium deposits can occur on myocardium and block conduction