Mixed Deck — All MRCP PART 1 Topics Flashcards

A patient returns from South-East Asia with cyclical fevers every 48 hours, rigors, and splenomegaly. Blood film shows ring forms and banana-shaped gametocytes within red blood cells. Which species of Plasmodium is responsible?

Answer: Plasmodium falciparum

Banana-shaped (crescent) gametocytes are pathognomonic of Plasmodium falciparum. While P. falciparum classically causes irregular fevers rather than strict 48-hour cycles, it can produce tertian periodicity. P. falciparum is the most dangerous species, capable of causing cerebral malaria, severe anaemia, and multi-organ failure.

Which valve lesion produces a mid-diastolic rumbling murmur best heard at the apex with the bell in the left lateral position?

Answer: Mitral stenosis

Mitral stenosis produces a low-pitched, mid-diastolic rumbling murmur, heard best at the apex with the bell of the stethoscope, with the patient in the left lateral position. It is often preceded by an opening snap and is accentuated by exercise.

A patient with COPD has an FEV1/FVC ratio of 0.6 and an FEV1 of 45% predicted. According to GOLD criteria, what severity is this?

Answer: GOLD 3 (severe)

GOLD severity is based on FEV1 % predicted (post-bronchodilator): GOLD 1 ≥80%, GOLD 2 50–79%, GOLD 3 30–49%, GOLD 4 <30%. An FEV1 of 45% predicted places this patient in GOLD 3 (severe). The FEV1/FVC <0.7 confirms obstruction.

A patient taking hydralazine for hypertension develops arthralgia, pleuritis, and a positive ANA. Anti-histone antibodies are positive but anti-dsDNA and complement levels are normal. What is the most likely diagnosis?

Answer: Drug-induced lupus erythematosus

Drug-induced lupus caused by hydralazine (also procainamide, isoniazid) is characterised by anti-histone antibodies, positive ANA, absence of anti-dsDNA, and normal complement; it resolves on drug withdrawal.

Which type of hypersensitivity reaction is responsible for Goodpasture's syndrome?

Answer: Type II (cytotoxic)

Goodpasture's syndrome is a type II hypersensitivity reaction where autoantibodies target the alpha-3 chain of type IV collagen in glomerular and alveolar basement membranes, causing glomerulonephritis and pulmonary haemorrhage.

A 25-year-old woman presents with haematuria, bilateral renal cysts on ultrasound, and a family history of renal failure. Genetic testing reveals a PKD1 mutation. What is the diagnosis?

Answer: Autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 (chromosome 16, 85% of cases) or PKD2 (chromosome 4). It is the most common inherited kidney disease, presenting with bilateral cysts, haematuria, hypertension, and progressive renal failure.

A patient with known asthma presents with acute breathlessness. Arterial blood gas shows pH 7.35, PaCO2 5.5 kPa, PaO2 8.0 kPa. What does the PaCO2 suggest about the severity of this exacerbation?

Answer: Life-threatening — indicates tiring and impending respiratory failure

In acute asthma, patients typically hyperventilate, producing a low PaCO2. A normal or rising PaCO2 (5.5 kPa) in acute asthma is a sinister sign indicating respiratory muscle fatigue and inability to maintain the hyperventilatory response. This is classified as a feature of life-threatening asthma by BTS/SIGN guidelines.

A 58-year-old woman with active rheumatoid arthritis is about to start methotrexate. Which baseline investigation is most critical before initiating this drug?

Answer: Liver function tests and full blood count

Methotrexate is hepatotoxic and myelosuppressive; baseline liver function tests and full blood count are mandatory before starting therapy, with regular monitoring every 4–12 weeks thereafter.

A 55-year-old man has a plasma osmolality of 295 mOsm/kg but his urine remains maximally dilute at 80 mOsm/kg despite water deprivation. After desmopressin administration, urine osmolality rises to 600 mOsm/kg. What is the diagnosis?

Answer: Cranial diabetes insipidus

The failure to concentrate urine despite water deprivation (raised plasma osmolality) indicates diabetes insipidus. The response to desmopressin (synthetic ADH) confirms the kidneys can respond, meaning the problem is insufficient ADH production — cranial diabetes insipidus.

A 70-year-old woman with atrial fibrillation has a CHA2DS2-VASc score of 4. According to NICE guidelines, what is the recommended anticoagulation strategy?

Answer: Direct oral anticoagulant (DOAC)

NICE recommends anticoagulation with a DOAC (apixaban, dabigatran, edoxaban, or rivarelbana) as first-line for stroke prevention in AF when CHA2DS2-VASc score is 2 or more. Aspirin alone is no longer recommended for stroke prevention in AF.

Which drug used for type 2 diabetes has been shown to reduce cardiovascular death and hospitalisation for heart failure in patients with established CVD?

Answer: Empagliflozin

SGLT2 inhibitors, particularly empagliflozin (EMPA-REG OUTCOME trial) and canagliflozin (CANVAS trial), have demonstrated significant reductions in cardiovascular death, hospitalisation for heart failure, and renal progression in patients with type 2 diabetes and established CVD or high CV risk.

A patient with small cell lung cancer presents with hyponatraemia (Na 118 mmol/L) and inappropriately concentrated urine. What paraneoplastic syndrome does this represent?

Answer: SIADH

SIADH (Syndrome of Inappropriate Antidiuretic Hormone secretion) is the most common paraneoplastic syndrome in small cell lung cancer. Ectopic ADH production causes dilutional hyponatraemia with inappropriately concentrated urine (urine osmolality >100 mOsm/kg despite low plasma osmolality).

A patient with heart failure has the following spirometry: FEV1 2.8L (predicted 3.5L), FVC 3.2L (predicted 4.2L), FEV1/FVC ratio 87.5%. What pattern does this show?

Answer: Restrictive pattern

The FEV1/FVC ratio is preserved (>70%) but both FEV1 and FVC are reduced, indicating a restrictive pattern. Heart failure causes pulmonary congestion and reduced lung compliance, leading to restriction.

What is the most common cause of acute liver failure in the UK?

Answer: Paracetamol overdose

Paracetamol (acetaminophen) overdose is the most common cause of acute liver failure in the UK, accounting for approximately 70% of cases. It causes hepatocellular necrosis via N-acetyl-p-benzoquinone imine (NAPQI) accumulation when glutathione stores are depleted.

A 35-year-old woman presents with fever, arthralgia, and a malar (butterfly) rash. Blood tests show pancytopaenia, raised anti-dsDNA antibodies, and low complement C3 and C4. What is the most likely diagnosis?

Answer: Systemic lupus erythematosus (SLE)

SLE characteristically presents in young women with multi-system involvement including malar rash, arthralgia, cytopaenias, and renal disease. Anti-dsDNA antibodies are highly specific for SLE and correlate with disease activity, particularly lupus nephritis. Low complement levels indicate active immune complex consumption.

Which marker is used to guide treatment decisions and monitor prognosis in non-Hodgkin's lymphoma?

Answer: Lactate dehydrogenase (LDH)

LDH is an important prognostic marker in non-Hodgkin's lymphoma, reflecting tumour bulk and cell turnover. It is incorporated into the International Prognostic Index (IPI) for DLBCL, alongside age, stage, performance status, and number of extranodal sites.

A 5-year-old child presents with fever, petechial rash, and neck stiffness. CSF shows raised WCC (predominantly neutrophils), raised protein, low glucose, and Gram-negative diplococci. What is the most likely causative organism?

Answer: Neisseria meningitidis

Neisseria meningitidis (meningococcus) is a Gram-negative diplococcus and the most common cause of bacterial meningitis in children and young adults in the UK. The petechial/purpuric rash is characteristic of meningococcal disease. Close contacts require ciprofloxacin chemoprophylaxis.

Which valvular lesion classically produces an early diastolic murmur best heard at the left sternal edge with the patient sitting forward?

Answer: Aortic regurgitation

Aortic regurgitation produces a high-pitched early diastolic decrescendo murmur best heard at the left sternal edge with the patient sitting forward and in held expiration. This position brings the aortic root closer to the chest wall.

Which cranial nerve is most commonly affected in raised intracranial pressure, causing a false localising sign?

Answer: Abducens nerve (CN VI)

The abducens nerve (CN VI) has the longest intracranial course and is most susceptible to stretching from raised intracranial pressure. This causes a lateral rectus palsy (inability to abduct the eye) which is a false localising sign — it does not indicate the site of the pathology.

A patient returning from sub-Saharan Africa presents with fever, rigors, and splenomegaly. Thick and thin blood films show ring forms within red blood cells. What is the treatment for falciparum malaria without complications?

Answer: Artemether-lumefantrine (Riamet)

Artemether-lumefantrine (Riamet) is the first-line treatment for uncomplicated Plasmodium falciparum malaria in the UK. Chloroquine resistance is widespread in P. falciparum. Quinine plus doxycycline/clindamycin is an alternative or second-line option.