A 61-year-old woman is admitted to the Emergency Department with central chest pain. It feels like her previous angina but is not relieved by nitrates. She has a history of ischaemic heart disease and 4 weeks ago underwent a percutaneous coronary intervention during which a stent was placed. This is her first episode of angina since the procedure.
What is the most likely diagnosis?
Correct Answer E: 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:
Risk factors:
Types of stent:
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.
Which of the following is responsible for the plateau phase of the myocardial action potential?
Correct Answer D: Slow influx of calcium is responsible for the plateau phase of the action potential.
Electrical activity of the heart:
NB: cardiac muscle remains contracted 10-15 times longer than skeletal muscle.
Conduction velocity:
A 40-year-old woman who is being treated for refractory hypertension undergoes a coronary angiogram after developing non-specific chest pains. The cardiologist takes a number of measurements during the procedure: Pressure (mmHg)
The blood pressure in her left arm taking during the procedure was 188/74 mmHg.
What is the most likely underlying diagnosis?
Correct Answer C: The most common type of coarctation of the aorta seen in adults is the post ductal variety, i.e. the aortic narrowing is distal to the ductus arteriosus. This means that the upper limb blood pressure is greater than that in the lower limbs as the narrowing occurs after the left subclavian artery branches from the aorta.
Another approach to answering this question is to look at the history. A young person with refractory hypertension raises the possibility of secondary, rather than essential (primary) hypertension. The only two diagnoses listed above which cause hypertension are coarctation and renal artery stenosis. This narrows the diagnostic possibilities and makes the question easier to answer.
Coarctation of the aorta: Coarctation of the aorta describes a congenital narrowing of the descending aorta.
Overview:
Features:
Associations:
A 57-year-old man who had a prosthetic mitral valve replacement 7 years ago presents with fever. An urgent echocardiogram shows features consistent with endocarditis.
What is the most suitable antibiotic therapy until blood culture results are known?
Correct Answer B: If the patient has a prosthetic valve and endocarditis is suspected the initial therapy should consist of intravenous vancomycin + rifampicin + gentamicin.
Infective endocarditis: prognosis and management
Poor prognostic factors:
Mortality according to organism:
Current antibiotic guidelines (source: British National Formulary)
Indications for surgery:
A 65-year-old female with a known history of heart failure presents for an annual check-up. She is found to have a blood pressure of 170/100 mmHg. Her current medications are furosemide and aspirin.
What is the most appropriate medication to add?
Correct Answer E: Both enalapril and bisoprolol have been shown to improve prognosis in patients with heart failure. Enalapril however would also be better at treating the hypertension. NICE guidelines recommend the introduction of an ACE inhibitor prior to a beta-blocker in patients with chronic heart failure.
Heart failure: drug management: A number of drugs have been shown to improve mortality in patients with chronic heart failure:
No long-term reduction in mortality has been demonstrated for loop diuretics such as furosemide.
NICE issued updated guidelines on management in 2010, key points include:
*Digoxin has also not been proven to reduce mortality in patients with heart failure. It may however improve symptoms due to its inotropic properties. Digoxin is strongly indicated if there is coexistent atrial fibrillation.
**Adults usually require just one dose but those with asplenia, splenic dysfunction or chronic kidney disease need a booster every 5 years.
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