MRCP Revision Notes

Another random selection from MRCP Part 1 practice questions - normal updates will resume in May!

Treatment of Hyperlipidaemia - Elevated cholesterol and triglycerides are suggestive of remnant hyperlipidaemia. The most appropriate treatment in this case would be a fibrate. Statins are predominantly used to treat cholesterol. Nicotinic acid lowers cholesterol and triglycerides but it is poorly tolerated (primarily due to cutaneous flushing). Bile acid sequestrants reduce cholesterol but may actually increase triglyceride concentrations and are poorly tolerated. The effects of statins are usually maximal by about 4 weeks after an increase in dose. Fibrates in combination with statins are effective although there is a theoretical risk of myositis when used in combination. In a patient with high cholesterol not responding to a statin, ezetimib may be helpful. Ezetimib inhibits cholesterol absorption from the gut.

Resting Membrane Potential - The resting neurone is polarized (-ve on the inside, +ve on the outside). At rest, the cell membranes are less permeable to sodium than they are to potassium. The outside of the neurone is rich in sodium ions. When stimulated, the neurone permeability changes allowing sodium in and postassium out. The depolarization resulting from this movement causes the generation of an action potential.

Myelodysplastic Syndrome - This is characterised by peripheral cytopenia with marrow full of developing cells. Maturation is abnormal and there is reduced cell survival. It can initially be detected from the presence of abnormal red cell maturation (ie. a raised MCV) in the absence of other causes of anaemia. The most common presenting symptom is fatigue and this condition is far more common in the elderly population.

Rheumatic Fever & Differential - This condition affects children in the age 4-15 group as a result of Group A streptococcal infection. It is common in the middle east, eastern Europe and South America. The arthritis is classically a fleeting migratory polyarthritis affecting the large joints although isolated arthritis is the presenting symptom in 15-40% of cases. Differential diagnosis includes:

Still’s disease (arthritis is usually much more persistent in the affected joint)

Polyarticular juvenile idiopathic arthritis (small joints initially affected, no fever)

Childhood dermatomyositis (age 4-10, classic rash + muscle weakness)

Familial Mediterranean Fever - autosomal recessive in certain ethnic groups, characterised by recurrent attacks of fever, arthritis and serositis. Abdominal or chest pain due to peritonitis / pleurisy may occur.

Chagas Disease - This is a tropical parasitic disease caused by infection with the flagellate potozoan Trypanosoma cruzi. It is associated with sudden cardiac failure due to dilated cardiomyopathy. It is a protozoan parasite, known as the ‘kissing bug’. Patients are often asymptomatic for many years following infection but may develop cardiac failure. It is most prevalent in Central and South America and may cause mega-oesophagus and mega-colon as a complication.