Cardiothoracic Surgery Prometric exam questions with answers

1. Question 1Anatomy of the Thoraxmedium

   A 60-year-old develops new hoarseness after a left upper lobectomy with extensive dissection in the aortopulmonary window. Which nerve is most likely injured and at which landmark?

   1. ALeft phrenic nerve, where it crosses the pericardium anterior to the hilum
   2. BLeft recurrent laryngeal nerve, where it hooks around the ligamentum arteriosum
   3. CLeft vagus nerve, where it crosses behind the hilum
   4. DLeft sympathetic chain, at the neck of the first rib
   Show answer and explanation▾

   Answer: B. Left recurrent laryngeal nerve, where it hooks around the ligamentum arteriosum

   The left recurrent laryngeal nerve loops under the aortic arch beside the ligamentum arteriosum, so it is at risk in the aortopulmonary window and causes hoarseness. Phrenic injury causes an elevated hemidiaphragm and dyspnoea, not hoarseness. The vagus lies behind the hilum and its pulmonary branches do not supply the larynx. Sympathetic chain injury gives Horner syndrome.

   Reference: Snell, Clinical Anatomy by Regions, 9th ed. (2012)

2. Question 2Arrhythmias and Conduction Defectshard

   A young man with Wolff-Parkinson-White syndrome has rapid pre-excited atrial fibrillation with a stable blood pressure. Which drug should be avoided?

   1. AIntravenous procainamide
   2. BIntravenous verapamil
   3. CIntravenous ibutilide
   4. DSynchronised cardioversion
   Show answer and explanation▾

   Answer: B. Intravenous verapamil

   AV nodal blockers such as verapamil, adenosine, digoxin and beta-blockers can speed conduction through the accessory pathway and cause ventricular fibrillation. Procainamide and ibutilide slow the accessory pathway, and cardioversion is safe and effective.

   Reference: 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients With Supraventricular Tachycardia

3. Question 3Cardiac and Pulmonary Physiologymedium

   A dilated failing left ventricle has a higher myocardial oxygen demand than a normal ventricle at the same pressure. Which principle best explains this?

   1. AFrank-Starling mechanism, because stroke volume rises with preload
   2. BBowditch effect, because contractility rises with heart rate
   3. CLaplace's law, because wall tension rises with radius
   4. DAnrep effect, because contractility rises with afterload
   Show answer and explanation▾

   Answer: C. Laplace's law, because wall tension rises with radius

   Laplace's law states that wall tension is proportional to pressure times radius divided by wall thickness, so a larger radius raises wall stress and oxygen use. The Frank-Starling mechanism describes the preload-stroke volume relation. The Bowditch and Anrep effects describe rate- and afterload-related contractility changes and do not explain higher wall stress.

   Reference: Hall, Guyton and Hall Textbook of Medical Physiology, 14th ed. (2020)

4. Question 4Cardiovascular and Pulmonary Pharmacologymedium

   After mitral valve replacement a patient has low cardiac output and a high pulmonary vascular resistance. Which inotrope increases contractility independently of beta-receptors and lowers pulmonary vascular resistance?

   1. ADopamine at a high infusion dose
   2. BMilrinone by continuous infusion
   3. CPhenylephrine as a continuous infusion
   4. DEpinephrine at a low infusion dose
   Show answer and explanation▾

   Answer: B. Milrinone by continuous infusion

   Milrinone inhibits phosphodiesterase 3, raising cAMP, which increases contractility and dilates pulmonary and systemic vessels, independent of beta-receptors. Dopamine and epinephrine act through adrenergic receptors. Phenylephrine is a pure alpha agonist that raises systemic resistance and can worsen right heart strain.

   Reference: Bojar, Manual of Perioperative Care in Adult Cardiac Surgery, 6th ed. (2021)

5. Question 5Ischemic Heart Diseaseeasy

   Within what time after CABG should aspirin be started if there is no bleeding concern?

   1. AWithin 6 hours
   2. BAfter 48 hours
   3. CAfter 5 days
   4. DAfter the first outpatient visit
   Show answer and explanation▾

   Answer: A. Within 6 hours

   Guidelines recommend aspirin within 6 hours of CABG to improve early graft patency. Waiting 48 hours or 5 days leaves the grafts unprotected during the period of highest thrombosis risk. Delaying to a clinic visit is not guideline practice.

   Reference: 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization

6. Question 6Congenital Heart Diseasesmedium

   A cyanotic neonate has transposition of the great arteries with an intact ventricular septum. After prostaglandin E1 and balloon atrial septostomy, what is the definitive operation?

   1. AArterial switch operation in the first weeks of life
   2. BAtrial switch (Mustard) operation
   3. CModified Blalock-Taussig shunt
   4. DPulmonary artery banding
   Show answer and explanation▾

   Answer: A. Arterial switch operation in the first weeks of life

   The arterial switch restores the normal ventricle-to-vessel relationship and is done in the first weeks, before the left ventricle loses its conditioning. The atrial switch leaves the right ventricle as the systemic pump and is now rare. A shunt and banding are palliative operations for other lesions.

   Reference: Sellke et al., Sabiston and Spencer Surgery of the Chest, 9th ed. (2016)

7. Question 7Ischemic Heart Diseasehard

   A 55-year-old needs CABG with a LIMA to the LAD and a second graft to a circumflex branch with 90% stenosis. Which is the best second conduit?

   1. ARadial artery from the non-dominant arm
   2. BLong saphenous vein harvested from the leg
   3. CRight gastroepiploic artery on a pedicle
   4. DCephalic vein harvested from the forearm
   Show answer and explanation▾

   Answer: A. Radial artery from the non-dominant arm

   Radial artery grafts to targets with high-grade stenosis have better long-term patency than saphenous vein, and guidelines support them as the second conduit. The gastroepiploic artery is used less often and has a more variable result. The saphenous vein is the standard alternative but has lower patency. The cephalic vein is not an established conduit.

   Reference: 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization

8. Question 8Radiology of Thoraxeasy

   A supine ICU chest radiograph shows a hyperlucent costophrenic sulcus on one side. What is the most likely diagnosis?

   1. APleural effusion
   2. BPneumothorax
   3. CLobar collapse
   4. DPericardial effusion
   Show answer and explanation▾

   Answer: B. Pneumothorax

   In supine patients air collects anteromedially and basally, giving the deep sulcus sign of pneumothorax. An effusion layers posteriorly and makes the lung base hazy. Lobar collapse shows increased density and volume loss, and pericardial effusion enlarges the cardiac silhouette.

   Reference: Sellke et al., Sabiston and Spencer Surgery of the Chest, 9th ed. (2016)

9. Question 9Diseases of Lung and Mediastinummedium

   A 50-year-old with generalised myasthenia gravis has a 4 cm encapsulated anterior mediastinal mass. What is the best surgical approach once optimised?

   1. ABiopsy of the mass and corticosteroids
   2. BTumour enucleation leaving the thymus
   3. CComplete thymectomy with en bloc resection of the mass
   4. DRadiotherapy of the mediastinum
   Show answer and explanation▾

   Answer: C. Complete thymectomy with en bloc resection of the mass

   A thymoma should be resected completely with the entire thymus, which also helps myasthenia control. Biopsy alone and enucleation risk incomplete resection and recurrence. Radiotherapy is used after surgery in selected invasive tumours, not as a substitute.

   Reference: Sellke et al., Sabiston and Spencer Surgery of the Chest, 9th ed. (2016)

10. Question 10Monitoring of Cardiac Patienthard

    In which condition does the pulmonary capillary wedge pressure overestimate the left ventricular end-diastolic pressure?

    1. AMitral stenosis
    2. BAcute severe aortic regurgitation
    3. CLeft ventricular non-compliance
    4. DPulmonary embolism
    Show answer and explanation▾

    Answer: A. Mitral stenosis

    In mitral stenosis a gradient across the valve keeps left atrial pressure above LVEDP, so wedge pressure overestimates it. In acute aortic regurgitation early mitral closure makes wedge pressure underestimate LVEDP. A stiff ventricle makes LVEDP higher than mean atrial pressure, and pulmonary embolism lowers wedge pressure.

    Reference: Bojar, Manual of Perioperative Care in Adult Cardiac Surgery, 6th ed. (2021)

11. Question 11Valvular Heart Diseaseeasy

    What is the usual INR target for a patient with a bileaflet mechanical mitral valve?

    1. A1.5 to 2.0
    2. B3.0 (range 2.5 to 3.5)
    3. C2.0 (range 1.8 to 2.2)
    4. D4.5 (range 4.0 to 5.0)
    Show answer and explanation▾

    Answer: B. 3.0 (range 2.5 to 3.5)

    A mechanical mitral prosthesis carries high thrombotic risk and needs an INR of 3.0. The 1.5 to 2.0 range applies only to selected low-risk aortic valves with specific designs, and 4.5 is dangerously high. An INR of 2.0 is below the target.

    Reference: 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease

12. Question 12Valvular Heart Diseasehard

    A 45-year-old is asymptomatic with severe primary mitral regurgitation, LVEF 55% and LV end-systolic dimension 42 mm. Which approach is recommended?

    1. AAnnual surveillance until symptoms develop
    2. BStart ACE inhibitor therapy and repeat echo at 5 years
    3. CReplace the valve with a mechanical prosthesis
    4. DMitral valve repair before symptoms develop
    Show answer and explanation▾

    Answer: D. Mitral valve repair before symptoms develop

    In severe primary MR, surgery is indicated before symptoms when LVEF is 60% or less or LVESD is 40 mm or more, and repair is preferred when feasible. Surveillance would allow irreversible LV damage. ACE inhibitors do not treat primary MR. Replacement is inferior to repair when repair is possible.

    Reference: 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease

13. Question 13Ischemic Heart Diseasemedium

    A patient with an inferior myocardial infarction develops acute pulmonary oedema and a short systolic murmur with a hyperdynamic left ventricle. Echocardiography shows a flail posteromedial papillary muscle. What is the treatment?

    1. AEmergency mitral valve replacement
    2. BDiuretics and observation for 6 weeks
    3. CPercutaneous balloon mitral valvotomy
    4. DCardiac resynchronisation therapy
    Show answer and explanation▾

    Answer: A. Emergency mitral valve replacement

    The posteromedial papillary muscle has a single blood supply from the posterior descending artery, so it ruptures after inferior infarction and causes acute severe mitral regurgitation. Medical therapy is a bridge only, and surgery should be urgent. Balloon valvotomy treats stenosis, and resynchronisation does not repair a flail leaflet.

    Reference: Bojar, Manual of Perioperative Care in Adult Cardiac Surgery, 6th ed. (2021)

14. Question 14Valvular Heart Diseasehard

    A patient with Staphylococcus aureus prosthetic aortic valve endocarditis develops a new prolonged PR interval on day 6 of antibiotics. What is the most likely complication and the plan?

    1. ADrug toxicity, with antibiotic change
    2. BSeptic coronary embolus, with PCI
    3. CPerivalvular abscess, with early surgery
    4. DValve thrombosis, with heparin
    Show answer and explanation▾

    Answer: C. Perivalvular abscess, with early surgery

    A new conduction delay in aortic valve endocarditis suggests an abscess extending to the septum near the AV node, which is an indication for early surgery. Antibiotic change would not address this. Coronary embolism and valve thrombosis do not typically cause a progressive PR interval change.

    Reference: 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease

15. Question 15Monitoring of Cardiac Patientmedium

    A central venous pressure trace shows intermittent large cannon a waves after aortic valve replacement. What is the most likely rhythm?

    1. ASinus tachycardia
    2. BAtrial flutter with 2:1 block
    3. CComplete heart block or junctional rhythm with AV dissociation
    4. DVentricular bigeminy
    Show answer and explanation▾

    Answer: C. Complete heart block or junctional rhythm with AV dissociation

    Cannon a waves occur when the atrium contracts against a closed tricuspid valve, as in AV dissociation. Sinus tachycardia gives normal a waves. Flutter with 2:1 block gives regular rapid a waves, and ventricular bigeminy alone does not produce regular cannon waves.

    Reference: Bojar, Manual of Perioperative Care in Adult Cardiac Surgery, 6th ed. (2021)

Last reviewed September 2026. Questions are original and written to the published exam blueprint; they are not taken from any real paper.