MRCP Part 2 Question Bank

Obstructive HCM with hypotension from worsened LVOT obstruction (exacerbated by sildenafil-induced vasodilation) requires IV fluid resuscitation and measures to increase preload, reversing factors that worsen obstruction.

Dynamic LVOT obstruction in HCM - systolic anterior motion (SAM) of mitral valve causes subaortic obstruction. Obstruction worsened by: (1) Reduced preload (dehydration, vasodilators), (2) Increased contractility (exercise, inotropes), (3) Reduced afterload (vasodilators including sildenafil/PDE5 inhibitors, this case). Sildenafil CONTRAINDICATED in HCM: causes systemic vasodilation → reduced afterload + reduced preload → increased LVOT gradient → hypotension/syncope (this case). Murmur increases with Valsalva (reduces preload).

Acute management of HCM with hypotension from worsened obstruction: (1) IV fluid bolus (500-1000ml crystalloid) - increases preload, expands LV cavity, reduces LVOT gradient, improves BP, (2) Trendelenburg position (legs elevated) - increases venous return/preload, (3) AVOID: inotropes (dobutamine worsens obstruction by increasing contractility), vasodilators (GTN worsens by reducing afterload/preload), diuretics (reduce preload worsening obstruction), (4) Consider phenylephrine (alpha-agonist vasoconstrictor) if fluids insufficient - increases afterload and SVR improving BP. Preventative: beta-blockers reduce contractility + slow HR (longer diastolic filling time), avoid PDE5 inhibitors/vasodilators/dehydration. Surgery/alcohol ablation for refractory symptomatic obstruction, not acute.

Per ESC HCM Guidelines: HCM + hypotension from obstruction = IV fluids + increase afterload. Remember: HCM + sildenafil + hypotension = worsened LVOT obstruction - IV FLUIDS increase preload, AVOID inotropes/vasodilators!

This patient had an unprovoked PE (no identifiable transient risk factor). According to NICE NG158, patients with unprovoked PE should be considered for extended anticoagulation beyond the initial 3–6 months, as the annual recurrence rate without treatment is approximately 10%. The AMPLIFY-EXT and EINSTEIN-CHOICE trials demonstrated that reduced-dose DOAC therapy (apixaban 2.5mg BD or rivaroxaban 10mg OD) provides effective protection against recurrence with a low bleeding risk, and is superior to aspirin. The benefit-risk ratio favours continued anticoagulation in men with unprovoked VTE (who have higher recurrence rates than women). Simply stopping after 3 months carries unacceptable recurrence risk. Full-dose lifelong anticoagulation would incur unnecessary bleeding risk when reduced-dose is equally effective for secondary prevention. Aspirin alone is inferior to reduced-dose DOACs for VTE prevention. A 6-month course then stopping does not address the ongoing risk. A negative thrombophilia screen does not alter the recommendation for extended therapy. Remember: Unprovoked PE - offer extended anticoagulation with reduced-dose DOAC (apixaban 2.5mg BD) for long-term secondary prevention; this is superior to aspirin with low bleeding risk.

This patient has clinical features of metastatic spinal cord compression (MSCC) - progressive lower limb weakness, upper motor neurone signs (brisk reflexes, upgoing plantars), sensory level at T8, and urinary retention with a palpable bladder. MSCC is an oncological emergency. According to NICE CG75, the immediate steps are: IV dexamethasone 16mg stat (to reduce cord oedema and preserve neurological function) and urgent MRI of the whole spine within 24 hours (to identify the level and extent of compression and detect multiple sites). MRI is the investigation of choice - plain radiographs cannot adequately assess cord compression. The MRI should image the entire spine as multiple compression levels are found in 30% of cases. Subsequent management depends on the MRI findings, prognosis, and functional status. Options include surgical decompression (if single-level compression, good performance status, and >3-month life expectancy) or urgent radiotherapy. The MSCC coordinator should be contacted immediately. Delaying treatment risks permanent paraplegia - the strongest predictor of outcome is pre-treatment neurological status. Remember: MSCC requires immediate IV dexamethasone 16mg and urgent whole-spine MRI - the patient's ambulatory status at treatment onset is the strongest predictor of outcome.