Cardio - Miscellaneous Flashcards
1
Q
Hypertrophic Obstructive Cardiomyopathy (HOCM)
A
- autosomal dominant disorder of muscle tissue caused by defects in the genes encoding sarcomere
- often asymptomatic
- exertional dyspnoea
- angina and syncope (typically following exercise)
due to subaortic hypertrophy of the ventricular septum, resulting in functional aortic stenosis - sudden death (most commonly due to ventricular arrhythmias), arrhythmias, heart failure
- ejection systolic murmur +/- systolic thrill at LLSE
- AF commonly seen
2
Q
HOCM - investigations
A
Echo findings
- mitral regurgitation
- systolic anterior motion of the anterior mitral valve leaflet
- asymmetric hypertrophy
ECG
- left ventricular hypertrophy
- non-specific ST segment and T-wave abnormalities
- progressive T wave inversion may be seen
- deep Q waves
3
Q
HOCM - management
A
Management - ABCDE
- Amiodarone
- Beta-blockers or verapamil for symptoms
- Cardioverter defibrillator
- Dual chamber pacemaker
- Endocarditis prophylaxis*
Drugs to avoid
- nitrates
- ACE-inhibitors
- inotropes
4
Q
Dilated Cardiomyopathy
A
- most common form of cardiomyopathy (90%)
Classic causes include
- alcohol
- Coxsackie B virus
- wet beri beri (thiamine deficiency with cardiovascular involvement)
- doxorubicin (chemotherapy agent)
- dilated heart leading to systolic dysfunction
- left ventricle more so than right ventricle
- eccentric hypertrophy (sarcomeres added in series)
Features
- classic findings of heart failure
- systolic murmur: stretching of the valves may result in mitral and tricuspid regurgitation
- S3
- ‘balloon’ appearance of the heart on CXR
5
Q
Restrictive cardiomyopathy
A
Classic causes include
amyloidosis
post-radiotherapy
Loeffler’s endocarditis
- the walls of the heart are stiff but not thickened, causing diastolic HF
- decreased exercise tolerance, fatigue, jugular venous distention, peripheral edema, and ascites. Arrhythmias and conduction blocks are common.
6
Q
Other causes of dilated and restrictive cardiomyopathy
A
“mixed” - many patients will have a genetic predisposition to cardiomyopathy which is then triggered by the secondary process, hence the ‘mixed’ dilated and restrictive category
(there’s a lot of overlap so this classification is not as widely used now)
Causes
- idiopathic: the most common cause
- myocarditis: e.g. Coxsackie B, HIV, diphtheria, Chagas
- ischaemic heart disease
- peripartum
- amyloidosis
- hypertension
- drugs, alcohol
- inherited (familial or syndromic)
7
Q
Abdominal Aortic Aneurysm (AAA)
A
- True aneurysm = all 3 layers of the arterial wall are involved; False aneurysm = only a single layer of fibrous tissue forms the aneurysm wall.
- commonest in elderly men - UK is introducing the aneurysm screening program = abdominal aortic ultrasound in all men aged 65 years
- RF: HTN, diabetes, smokers, connective tissue diseases (e.g. marfan’s)
- Most AAA are an incidental finding.
- Symptoms most often relate to rupture or impending rupture (The risk is related to aneurysm size) - abdominal, back, and groin pain are typical
8
Q
AAA - investigations
A
- Ultrasound remains the definitive test for initial diagnosis and screening
(all men get offered on at age 65)
Aorta width < 3 = normal
Aorta width 3 - 4.4 cm (small aneurysm) - rescan in 12 months
Aorta width 4.5 - 5.4 (medium aneurysm) - rescan in 3 months
Aorta width 5.5 or more (large aneurysm) - refer to vascular surgery within 2 weeks - most vascular surgeons will subject patients with an aneurysm size of 5cm or greater to CT scanning of the chest, abdomen and pelvis with the aim of delineating anatomy and planning treatment
Indications for surgery
- aneurysm is between 5.5cm and 6cm.
- symptomatic aneurysm
- rupture
9
Q
AAA - management
A
Low risk –> conservative, US monitoring
High risk –> refer for probable intervention
- Abdominal aortic aneurysm repair: aneurysm dissected and aorta clamped –> longitudinal aortotomy –> atherectomy –> graft insertion –> suture, clamps off
- Post operatively: ITU (Almost all)
(Increasingly patients are now being offered endovascular aortic aneurysm repair.)
Complications:
- Embolic- gut and foot infarcts
- Cardiac - re-perfusion injury, effects of cross clamp
- Wound problems
- graft infection and aorto-enteric fistula
10
Q
Aortic Dissection - features
A
- tear in the tunica intima of the wall of the aorta
- RF: HTN, trauma, bicuspic aortic valve, marfan’s
- chest pain: typically severe, radiates through to the back and ‘tearing’ in nature
(anterior chest pain- ascending aorta, back pain - descending aorta) - aortic regurgitation, SOB, pulse deficit (in different arms), radio-radial delay
Stanford classification
type A - ascending aorta, 2/3 of cases
type B - descending aorta, distal to left subclavian origin, 1/3 of cases
11
Q
Aortic Dissection - investigations
A
- CXR: change in morphology, mediastinal widening, intimal calcification
- CT angiography with contrast
- CT chest
- Echo (transoesophageal): shows the false lumen
12
Q
Aortic Dissection - management
A
Type A surgical management (open or endovascular aortic repair), but BP should be controlled to a target systolic of 100-120 mmHg whilst awaiting intervention
Type B
- conservative management: bed rest, opioids
- reduce BP: IV labetalol to prevent progression
Complications of backward tear
- aortic incompetence/regurgitation
- MI: inferior pattern often seen due to right coronary involvement
Complications of forward tear
- unequal arm pulses and BP
- stroke
- renal failure
13
Q
Acute Pericarditis
A
- causes: viral infections (Coxsackie), TB, uraemia (causes ‘fibrinous’ pericarditis), post-MI (Dressler’s syndrome), connective tissue disease, hypothyroidism
Features
- chest pain: may be pleuritic. Is often relieved by sitting forwards
- other symptoms include non-productive cough, dyspnoea and flu-like symptoms (viral prodrome)
- O/E: pericardial rub, tachypnoea, tachycardia
14
Q
Acute Pericarditis - Ix and Management
A
Investigations
- ECG changes: global/widespread, ‘saddle-shaped’ ST elevation; PR depression: most specific ECG marker for pericarditis
- all patients with suspected acute pericarditis should have transthoracic echocardiography
Management
- treat the underlying cause
- a combination of NSAIDs and colchicine is now generally used for first-line for patients with acute idiopathic or viral pericarditis
15
Q
Constrictive Pericarditis
A
- causes: any cause of pericarditis, particularly TB
Features
- dyspnoea
- right heart failure: elevated JVP, ascites, oedema, hepatomegaly
- pericardial knock - loud S3
- Kussmaul’s sign is positive
CXR
pericardial calcification
