Cardiology

Question 1

Causes of Prolonged PR interval

SLIM HAAIRD

Answer 1

Causes of a prolonged PR interval

Sarcoidosis

Lyme disease

Idiopathic

myotonic dystrophy

hypokalaemia*

aortic root pathology e.g. abscess secondary to endocarditis

athletes

ischaemic heart disease

rheumatic fever

digoxin toxicity

A prolonged PR interval may also be seen in athletes

A short PR interval is seen in Wolff-Parkinson-White syndrome

*hyperkalaemia can rarely cause a prolonged PR interval, but this is a much less common association than hypokalaemia

Question 2

Abnnormal P waves. What causes:

1) P-pulmonale
2) P-mitrale

Think is the P wave too tall (>2.5mm) or is the P wave too wide ( 2 small boxes), then consider strial chamber enlargment.

Answer 2

1) P-pulmonale: Pulmonary disease (Cor-pulmonale). pulmonary valve stenosis
2) P-mitrale: mitral stenosis

If an atrium becomes enlarged (typically as a compensatory mechanism) its contribution to the p wave will be enhanced. Typically changes are in lead II and VI.

P-pulmonale, so called because pulmonary disease is the most common cause, where enlargement of the right ventricle is due to increased resistance of blood emptying into the right ventricle. This may be due to pulmonary valve stenosis, increased pulmonary pressure etc. The right atrium must then enlarge (hypertrophy) in order to pump blood into the right ventricle. Right atrial enlargement (hypertrophy) leads to stronger electrical currents and thus enhancement of the contribution of the right atrium to the P wave.

P-Mitrale, so called because mitral valve disease is the most common cause. If the left atrium encounters increased resistance (eg due to mitral valve stenosis) it becomes enlarged (hypertrophy) which amplifies it’s contribution to the P wave. The second hump in lead II becomes larger and the negative deflection in V1 becomes deeper.

Question 3

the normal cross sectional area of the mitral valve is 4-6 sq cm. A ‘tight’ mitral stenosis implies a …..

Answer 3

cross sectional area of < 1 sq cm

Question 4

Features of severe mitral stenosis

Answer 4

1) length of murmur increases
2) opening snap becomes closer to S2

Question 5

What happens to the opening snap of mitral stenosis when the vakve is heavily calcified?

Answer 5

Openiong snap is characteristically lost with heavy valvular calcification

An opening snap suggests that the mitral valve is mobile. It is not heard when the valve is heavily calcified

Question 6

For degenerative nitral regurgitation what surgical treatment is preferred- valve repair of valve replacment?

Answer 6

Valve repair

The evidence for repair over replacement is strong in degenerative regurgitation, and is demonstrated through lower mortality and higher survival rates

When this is not possible, valve replacement with either an artificial valve or a pig valve is considered

Question 7

Features of more severe mitral regurgitation

Answer 7

Apex beat displacement

Systolic thrill

Question 8

Mitral Valve prolapse is usually idiopathic. However it may have certain associations…

TWO FLAME PPPC

Answer 8

Turner’s syndrome

Wolff-Parkinson White syndrome

osteogenesis imperfecta

Fragile X

long-QT syndrome

ASD

Marfan’s syndrome

Ehlers-Danlos Syndrome

pseudoxanthoma elasticum

polycystic kidney disease

PDA

cardiomyopathy

Question 11

S2 is caused by closure of the pulmonic and aortic valves. What causes wide splitting?

Answer 11

deep inspiration

RBBB

pulmonary stenosis

severe mitral regurgitation

Question 12

S2 is caused by closure of the pulmonic and aortic valves. What are 5 causes of paradoxical splitting?

Answer 12

Causes of a reversed (paradoxical) split S2 (P2 occurs before A2)

LBBB

severe aortic stenosis

right ventricular pacing

WPW type B (causes early P2)

patent ductus arteriosus

Question 13

Causes of fixed split S2

Answer 13

atrial septal defect

Question 14

Atrial septal defect effect on heart sounds

Answer 14

fixed split S2

Question 15

Causes of a soft S2

Answer 15

aortic stenosis

Question 16

3 Causes of a loud S2

Answer 16

Causes of a loud S2

hypertension: systemic (loud A2) or pulmonary (loud P2)

hyperdynamic states

atrial septal defect without pulmonary hypertension

Question 17

S3 heart sound is due to rapid ventricular filling during diastole. Give 4 causes?

Answer 17

• considered normal if < 30 years old (may persist in women up to 50 years old)
• left ventricular failure (e.g. dilated cardiomyopathy),
• constrictive pericarditis (called a pericardial knock)
• mitral regurgitation

Question 18

S4 is caused by atrial contraction against a stiff (hypertrophied) left ventricle. Give Causes?

Answer 18

S4 (fourth heart sound)

may be heard in 1) aortic stenosis, 2)HOCM, 3) hypertension

caused by atrial contraction against a stiff ventricle

therefore coincides with the P wave on ECG

in HOCM a double apical impulse may be felt as a result of a palpable S4

Question 19

describe murmurs and heart sounds of mitral valve murmurs

1) Mitral regurgitation
2) Mitral valve prolapse
3) Mitral stenosis

Answer 19

1) MR- blowing pansystolic murmur at the apex, radiating to axilla. +/- quite S1 (due to incomplete valve closure) and in severe cases wide splitting of S2
2) Mitral Valve prolapse- mid-systolic click (occurs later if pt squatting) + late systolic murmur (longer if pt standing
3) MS- mid to late diastolic murmur. loud S1, opening snap

Question 20

describe murmurs and heart sounds of aortic valve murmurs

1) Aortic Stenosis
2) HOCM
3) Coarctation of the aorta
4) Aortic regurgitation

Answer 20

1) AS: Ejectio systolic murmur, radiating to the carotids. loud S4 (from stiff or hypertrophic left venrticle)
2) HOCM: Ejection systolic murmur, increased with valsalva manouveur and reduced by squatting
3) Coarctation of the aorta: Mid-systolic murmur, maximal over the back
4) AR: Early distaolic murmur increased by handgroup manouveur