Question 151#

A 68-year-old man with a past history of aortic stenosis is reviewed in clinic.

Which one of the following features would most guide the timing of surgery?

A. Symptomatology of patient

Correct Answer A:

Aortic stenosis management: AVR if symptomatic, otherwise cut-off is gradient of 50 mmHg.

Aortic stenosis:

Features of severe aortic stenosis:

Features of severe aortic stenosis:

• Narrow pulse pressure
• Slow rising pulse
• Delayed ESM
• Soft/absent S2
• S4
• Thrill
• Duration of murmur
• Left ventricular hypertrophy or failure

Causes of aortic stenosis:

• Degenerative calcification (most common cause in older patients > 65 years)
• Bicuspid aortic valve (most common cause in younger patients < 65 years)
• William's syndrome (supravalvular aortic stenosis)
• Post-rheumatic disease
• Subvalvular: HOCM

Management:

• If asymptomatic then observe the patient is general rule
• If symptomatic then valve replacement
• If asymptomatic but valvular gradient > 50 mmHg and with features such as left ventricular systolic dysfunction then consider surgery
• Balloon valvuloplasty is limited to patients with critical aortic stenosis who are not fit for valve replacement

Question 152#

Which of the following conditions is least associated with coarctation of the aorta?

A. Neurofibromatosis

Correct Answer C:

Coarctation of the aorta:
Coarctation of the aorta describes a congenital narrowing of the descending aorta. 

Overview:

• More common in males (despite association with Turner's syndrome)

Features:

• Infancy: heart failure
• Adult: hypertension
• Radio-femoral delay
• Mid systolic murmur, maximal over back
• Apical click from the aortic valve
• Notching of the inferior border of the ribs (due to collateral vessels) is not seen in young children

Associations:

• Turner's syndrome
• Bicuspid aortic valve
• Berry aneurysms
• Neurofibromatosis 

Question 153#

Which one of the following statements regarding prosthetic heart valves is correct?

A. Antibiotic prophylaxis is still recommended for patients with mechanical valves who have dental procedures

Correct Answer E:

Prosthetic heart valves:

The most common valves which need replacing are the aortic and mitral valve. There are two main options for replacement: biological (bioprosthetic) or mechanical. 

 

Question 154#

Which one of the following statements regarding percutaneous coronary intervention (PCI) is incorrect?

A. Stent thrombosis usually occurs in the first month

Correct Answer E:

PCI - patients with drug-eluting stents require a longer duration of clopidogrel therapy.

Percutaneous coronary intervention:

Percutaneous coronary intervention (PCI) is a technique used to restore myocardial perfusion in patients with ischaemic heart disease, both in patients with stable angina and acute coronary syndromes. Stents are implanted in around 95% of patients - it is now rare for just balloon angioplasty to be performed.

Following stent insertion migration and proliferation of smooth muscle cells and fibroblasts occur to the treated segment. The stent struts eventually become covered by endothelium. Until this happens there is an increased risk of platelet aggregation leading to thrombosis.

Two main complications may occur:

• Stent thrombosis: due to platelet aggregation as above. Occurs in 1-2% of patients, most commonly in the first month. Usually presents with acute myocardial infarction
• Restenosis: due to excessive tissue proliferation around stent. Occurs in around 5-20% of patients, most commonly in the first 3-6 months. Usually presents with the recurrence of angina symptoms

Risk factors:

Include diabetes, renal impairment and stents in venous bypass grafts Types of stents:

• Bare-metal stent (BMS)
• Drug-eluting stents (DES): stent coated with paclitaxel or rapamycin which inhibit local tissue growth. Whilst this reduces restenosis rates the stent thrombosis rates are increased as the process of stent endothelisation is slowed 

Following insertion the most important factor in preventing stent thrombosis is antiplatelet therapy.

Aspirin should be continued indefinitely. The length of clopidogrel treatment depends on the type of stent, reason for insertion and consultant preference.

Question 155#

You review a 75-year-old man who complains of palpitations. He was diagnosed with atrial fibrillation around four months ago and started on digoxin 125 mcg od and warfarin. Despite this treatment he still feels his 'heart race' regularly. On examination his pulse is 96/min irregularly irregular and respiratory examination is unremarkable.

What is the most appropriate next step in management?

A. Switch digoxin for verapamil

Correct Answer D:

Adding a beta-blocker would be the best option here. It will help control the heart rate and may have cardioprotective properties in certain patients (e.g. Those with heart failure, ischaemic heart disease or hypertension). 

Atrial fibrillation: rate control and maintenance of sinus rhythm:

The Royal College of Physicians and NICE published guidelines on the management of atrial fibrillation (AF) in 2006. The following is also based on the joint American Heart Association (AHA), American College of Cardiology (ACC) and European Society of Cardiology (ESC) 2012 guidelines.

Agents used to control rate in patients with atrial fibrillation:

• Beta-blockers
• Calcium channel blockers
• Digoxin (not considered first-line anymore as they are less effective at controlling the heart rate during exercise. However, they are the preferred choice if the patient has coexistent heart failure)

Agents used to maintain sinus rhythm in patients with a history of atrial fibrillation:

• Sotalol
• Amiodarone
• Flecainide
• Others (less commonly used in UK): disopyramide, dofetilide, procainamide, propafenone, quinidine

The table below indicates some of the factors which may be considered when considering either a rate control or rhythm control strategy: