Cardiology 2

Question 1

What are the risk factors for infective endocarditis?

Answer 1

Rheumatic valve disease (30%)
Prosthetic valves
Congenital heart defects
Intravenous drug users (IVDUs, e.g. typically causing tricuspid lesion)
Others: recent piercings

Question 2

Which organisms cause infective endocarditis?

Answer 2

Staphylococcus aureus
Streptococcus viridans is the commonest cause in patients from developing countries
S. epidermidis is a more likely causative organism of infective endocarditis if the patient has prosthetic valves

Question 3

What are the ECG features of hypokalaemia?

Answer 3

U waves
small or absent T waves (occasionally inversion)
prolong PR interval
ST depression
long QT

Question 4

What is B-type natriuretic peptide?

Answer 4

Hormone produced mainly by the left ventricular myocardium in response to strain
Raised levels caused by heart failure, myocardial ischaemia, valvular disease, chronic kidney disease
ACE inhibitors, angiotensin-2 receptor blockers and diuretics reduce BNP
Effects of BNP:
vasodilator
diuretic and natriuretic
suppresses both sympathetic tone and the renin-angiotensin-aldosterone system

Question 5

What are the features of mitral stenosis?

Answer 5

Caused by rheumatic fever 
Mid-late diastolic murmur (best heard in expiration)
Loud S1, opening snap
Low volume pulse
Malar flush
Atrial fibrillation

Question 6

What does ABPI suggest?

Answer 6

Below 0.9 is suggestive of arterial disease

Below 0.5 is suggestive of severe arterial disease

Question 7

What are the symptoms and signs of peripheral arterial disease?

Answer 7

Asymptomatic
Claudication (leg cramping relieved at rest)
Leg pain at rest
Ulceration
Gangrene
Absent leg and foot pulses
Cold white legs
Atrophic skin
Arterial ulcers
Long capillary filling time (over 15s in severe ischemia)

Question 8

What are the heart sounds?

Answer 8

S1
closure of mitral and tricuspid valves
soft if long PR or mitral regurgitation
loud in mitral stenosis
S2
closure of aortic and pulmonary valves
soft in aortic stenosis
splitting during inspiration is normal
S3 (third heart sound)
caused by diastolic filling of the ventricle
considered normal if < 30 years old (may persist in women up to 50 years old)
heard in left ventricular failure (e.g. dilated cardiomyopathy), constrictive pericarditis (called a pericardial knock) and mitral regurgitation
S4 (fourth heart sound)
may be heard in aortic stenosis, HOCM, 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 9

What are the histology finding post MI?

Answer 9

0-24hr post-MI histology findings: early coagulative necrosis, neutrophils, wavy fibres, hypercontraction of myofibrils. High risk of ventricular arrhythmia, HF and cardiogenic shock
1-3 days post-MI histology: Extensive coagulative necrosis, neutrophils (associated with fibrinous pericarditis)
3-14 days post-MI histology: macrophages + granulation tissue at margins. High risk of free wall rupture, papillary muscle rupture and LV pseudoaneurysm
2 weeks to several months post-MI histology: contracted scar complete. Associated with Dressler syndrome, HF, arrhythmias, mural thrombus

Question 10

What are the features of atrial myxoma?

Answer 10

Most common primary cardiac tumour
systemic: dyspnoea, fatigue, weight loss, pyrexia of unknown origin, clubbing
emboli
atrial fibrillation
mid-diastolic murmur, ‘tumour plop’
echo: pedunculated heterogeneous mass typically attached to the fossa ovalis region of the interatrial septum
More common in females

Question 11

What are the oxygen saturation levels in the heart?

Answer 11

70%- RA, RV, PA

100%- LA, LV, aorta

Question 12

What are the coronary territories seen on an ECG?

Answer 12

Anteroseptal- V1-V4- Left anterior descending
Inferior- II, III, aVF- Right coronary
Anterolateral- V4-6, I, aVL- Left anterior descending or left circumflex
Lateral- I, aVL +/- V5-6- Left circumflex
Posterior Tall R waves- V1-2- Usually left circumflex, also right coronary

Question 13

What are the complications of an MI?

Answer 13

Cardiac arrest (VF)
Cardiogenic shock 
Chronic heart failure 
Tachyarrhythmias- VF/VT
Bradyarrhythmias- atrioventricular block (more common in inferior MIs)
Pericarditis- 48 hours post MI, Dressler's syndrome several weeks later (fever, pleuritic pain, pericardial effusion and a raised ESR. It is treated with NSAIDs)
Left ventricular aneurysm 
Left ventricular free wall rupture
Ventricular septal defect
Acute mitral regurgitation

Question 14

What are the reversible causes of cardiac arrest?

Answer 14

Hypoxia
Hypovolaemia
Hyperkalaemia, hypokalaemia, hypoglycaemia, hypocalcaemia, acidaemia and other metabolic disorders
Hypothermia
Thrombosis (coronary or pulmonary)
Tension pneumothorax
Tamponade – cardiac
Toxins

Question 15

What is Wolf-Parkinson white syndrome?

Answer 15

Caused by a congenital accessory conducting pathway between the atria and ventricles leading to a atrioventricular re-entry tachycardia (AVRT). As the accessory pathway does not slow conduction AF can degenerate rapidly to VF
short PR interval
wide QRS complexes with a slurred upstroke - ‘delta wave’
left axis deviation if right-sided accessory pathway*
right axis deviation if left-sided accessory pathway*
Associated with:
HOCM
mitral valve prolapse
Ebstein’s anomaly
thyrotoxicosis
secundum ASD
LEFT AXIS DEVIATION

Question 16

What are Aschoff bodies?

Answer 16

Granulomatous nodules consisting of giant cells around areas of fibrinoid necrosis in the heart of the patient- found in RHEUMATIC heart fever

Question 17

What is rheumatic fever?

Answer 17

Develops following an immunological reaction to recent (2-6 weeks ago) Streptococcus pyogenes infection.
Diagnosis based on 2 major or 1 major with 2 minor
MAJOR
erythema marginatum
Sydenham’s chorea: this is often a late feature
polyarthritis
carditis and valvulitis (eg, pancarditis)*
subcutaneous nodules
MINOR
raised ESR or CRP
pyrexia
arthralgia (not if arthritis a major criteria)
prolonged PR interval

Question 18

What are the features of aortic regurgitation?

Answer 18

Early diastolic murmur: intensity of the murmur is increased by the handgrip manoeuvre
Collapsing pulse
Wide pulse pressure
Quinke’s sign (nailbed pulsation)
De Musset’s sign (head bobbing)
Mid-diastolic Austin-Flint murmur in severe AR - due to partial closure of the anterior mitral valve cusps caused by the regurgitation streams

Question 19

What are the causes of aortic regurgitation?

Answer 19

Valve disease:
rheumatic fever
infective endocarditis
connective tissue diseases e.g. RA/SLE
bicuspid aortic valve

Aortic root disease:
aortic dissection
spondylarthropathies (e.g. ankylosing spondylitis)
hypertension
syphilis
Marfan's, Ehler-Danlos syndrome

Question 20

What are the features of aortic dissection?

Answer 20

chest pain: typically severe, radiates through to the back and ‘tearing’ in nature
aortic regurgitation
hypertension
No ECG changes or ST-segment elevation may be seen in the inferior leads
Hypovolaemic shock due to bloodless (pale, clammy, cold, tachycardic and hypotensive)

Question 21

What are the associations of aortic dissection?

Answer 21

Hypertension: the most important risk factor
Trauma
Bicuspid aortic valve
Collagens: Marfan’s syndrome, Ehlers-Danlos syndrome
Turner’s and Noonan’s syndrome
Pregnancy
Syphilis

Question 22

How is aortic dissection classified?

Answer 22

Stanford classification
type A - ascending aorta, 2/3 of cases
type B - descending aorta, distal to left subclavian origin, 1/3 of cases
DeBakey classification
type I - originates in ascending aorta, propagates to at least the aortic arch and possibly beyond it distally
type II - originates in and is confined to the ascending aorta
type III - originates in descending aorta, rarely extends proximally but will extend distally