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Iraqi Board Thoracic & Cardiovascular Surgery study materials
Iraqi Board Thoracic & Cardiovascular Surgery study resources

Iraqi Board Thoracic & Cardiovascular Surgery practice questions

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Question 1Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 58-year-old man with acute type A aortic dissection is taken to theatre. Which structure most commonly requires replacement when the aortic root is preserved using a supracoronary tube graft?

  1. The entire aortic arch with all head vessels
  2. The aortic valve leaflets
  3. The mitral valve annulus
  4. The sinotubular junction and ascending aorta Correct answer.

Explanation

A supracoronary interposition graft replaces the ascending aorta and restores the sinotubular junction while leaving the native aortic valve and sinuses in place. The sinotubular junction is the segment resected and sized for the tube graft in this technique.

Question 2Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which finding on transthoracic echocardiography is the most specific sign of cardiac tamponade in a patient after cardiac surgery?

  1. Aortic sclerosis
  2. Right ventricular diastolic collapse Correct answer.
  3. Left ventricular hypertrophy
  4. Mitral annular calcification

Explanation

Right ventricular diastolic collapse reflects the raised pericardial pressure exceeding right ventricular filling pressure, a hallmark of tamponade physiology. Chamber collapse during diastole is more specific than simple effusion size.

Question 3Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient with severe symptomatic aortic stenosis and normal left ventricular ejection fraction is being assessed for intervention. Which parameter best reflects the severity of stenosis when the mean gradient is low?

  1. Left atrial size
  2. Aortic valve area calculated by the continuity equation Correct answer.
  3. Presence of a fourth heart sound
  4. Peak aortic jet velocity below 2.5 m/s

Explanation

When gradients are low, valve area derived from the continuity equation remains the standard measure of stenosis severity because it accounts for flow. A calculated area of 1.0 cm² or less supports severe stenosis.

Question 4Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which coronary artery is most commonly injured during a standard aortic valve replacement when aortotomy sutures are placed deeply?

  1. The posterior descending artery
  2. The circumflex artery in the atrioventricular groove
  3. The right coronary artery ostium Correct answer.
  4. The left main coronary artery ostium

Explanation

The right coronary ostium lies close to the anterior aortotomy line and is the vessel most frequently compromised by deeply placed annular or aortotomy sutures. Injury produces right ventricular ischaemia and inferior ECG changes.

Question 5Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 45-year-old woman has a large pericardial effusion with a thickened, inflamed pericardium and a friction rub. Which initial therapy is most appropriate for suspected acute pericarditis?

  1. Systemic corticosteroids as first-line therapy
  2. Immediate pericardiectomy
  3. High-dose nonsteroidal anti-inflammatory drugs plus colchicine Correct answer.
  4. Intrapericardial streptokinase

Explanation

Acute idiopathic or viral pericarditis is treated first with NSAIDs and colchicine, which reduce symptoms and recurrence. Corticosteroids are reserved for specific indications because they increase recurrence risk.

Question 6Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which of the following is the most important modifiable risk factor for early graft failure after coronary artery bypass grafting?

  1. Family history of coronary disease
  2. Continued smoking Correct answer.
  3. Male sex
  4. Patient age

Explanation

Smoking accelerates atherosclerosis and thrombosis and is the major modifiable contributor to early and late graft failure. Cessation before and after surgery improves outcomes.

Question 7Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which conduit is the preferred choice for coronary artery bypass grafting because of superior long-term patency?

  1. A free radial artery to the circumflex artery
  2. The right gastroepiploic artery to the right coronary artery
  3. A reversed saphenous vein graft to the left anterior descending artery
  4. The left internal thoracic artery to the left anterior descending artery Correct answer.

Explanation

The left internal thoracic artery grafted to the left anterior descending artery has the best long-term patency of all conduits and improves survival. It is the standard first conduit in surgical revascularisation.

Question 8Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient develops a harsh systolic murmur and haemodynamic collapse on the first postoperative day after mitral valve repair. Which complication should be suspected first?

  1. Tricuspid regurgitation
  2. Pulmonary stenosis
  3. Acute mitral regurgitation from repair failure Correct answer.
  4. Aortic stenosis

Explanation

Acute severe mitral regurgitation from a failed repair presents with a new systolic murmur, pulmonary oedema, and cardiogenic shock. It is a surgical emergency requiring prompt reoperation.

Question 9Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 70-year-old man with severe aortic stenosis and a porcelain aorta is considered for transcatheter aortic valve implantation. Which anatomical feature most strongly influences the choice of a transfemoral approach?

  1. Iliofemoral artery diameter and tortuosity Correct answer.
  2. Left ventricular mass index
  3. Serum creatinine level
  4. Presence of a permanent pacemaker

Explanation

Transfemoral access requires iliofemoral arteries of adequate calibre and acceptable tortuosity to pass the delivery system. Severe peripheral disease may mandate an alternative access route such as transapical or transaortic.

Question 10Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

During cardiopulmonary bypass, which strategy best reduces the risk of postoperative bleeding in a patient with normal coagulation?

  1. Aprotinin in all patients
  2. Deliberate hypothermia to 20 degrees Celsius
  3. Full heparin reversal with protamine after separation from bypass Correct answer.
  4. Routine platelet transfusion before weaning

Explanation

Adequate protamine reversal of heparin restores coagulation after bypass and is the cornerstone of reducing postoperative bleeding. Additional agents are reserved for specific indications.

Question 11Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 62-year-old woman with rheumatic mitral stenosis in atrial fibrillation is undergoing mitral valve replacement. Which additional procedure should be strongly considered at the time of surgery?

  1. Tricuspid valve replacement
  2. Left atrial appendage exclusion or ligation Correct answer.
  3. Aortic root replacement
  4. Coronary artery bypass of all three vessels

Explanation

In atrial fibrillation with mitral stenosis, the left atrial appendage is a major source of thrombus, and surgical exclusion reduces stroke risk. It is commonly performed alongside mitral surgery.

Question 12Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 55-year-old man with acute type A dissection has malperfusion of the right leg and a normal aortic valve. Which operative strategy is most appropriate?

  1. Pericardiocentesis alone
  2. Total arch replacement with elephant trunk in all cases
  3. Supracoronary tube graft replacement of the ascending aorta with repair of the aortic valve Correct answer.
  4. Aortic valve replacement with a mechanical prosthesis

Explanation

The standard operation for type A dissection with a normal valve is supracoronary ascending aortic replacement, which resects the intimal tear and restores true lumen flow. Valve-sparing repair avoids unnecessary prosthetic replacement.

Question 13Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient with a mechanical mitral valve develops haematuria and anaemia. Which laboratory finding is most consistent with haemolysis due to paravalvular leak?

  1. Low erythrocyte sedimentation rate
  2. Elevated serum amylase
  3. Isolated hypercalcaemia
  4. Elevated lactate dehydrogenase with low haptoglobin Correct answer.

Explanation

Intravascular haemolysis from a paravalvular leak or high shear across a prosthesis raises LDH and depletes haptoglobin. These markers support the diagnosis alongside echocardiography.

Question 14Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 66-year-old man with severe aortic stenosis and a left ventricular ejection fraction of 30 percent has a low mean gradient despite a calculated valve area of 0.8 cm². Which investigation is most useful to confirm true severe stenosis?

  1. 24-hour Holter monitoring
  2. Coronary computed tomography calcium scoring
  3. Dobutamine stress echocardiography Correct answer.
  4. Cardiac magnetic resonance angiography of the aorta

Explanation

Dobutamine stress echocardiography distinguishes true severe stenosis from pseudosevere stenosis in low-flow, low-gradient states by assessing flow reserve and changes in valve area and gradient. It also guides prognosis.

Question 15Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 40-year-old man with Marfan syndrome has an aortic root of 5.2 cm. Which operation best preserves native valve function while addressing the root?

  1. Bentall procedure with a mechanical valve
  2. Valve-sparing aortic root replacement Correct answer.
  3. Supracoronary tube graft alone
  4. Aortic valve balloon valvuloplasty

Explanation

Valve-sparing root replacement removes the dilated sinuses and reimplantsthe native valve, avoiding anticoagulation in a young patient. It is preferred when the leaflets are normal.

Question 16Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient undergoing coronary artery bypass grafting has a severely calcified ascending aorta. Which strategy best reduces the risk of perioperative stroke?

  1. Routine intra-aortic balloon pump insertion
  2. Cross-clamping the aorta at high pressure
  3. Off-pump grafting with no-touch aortic technique Correct answer.
  4. Systemic hypothermia to 18 degrees Celsius

Explanation

Avoiding aortic manipulation with an off-pump no-touch technique in a severely calcified aorta reduces embolic stroke risk. Clamping such a vessel can dislodge atheroma.

Question 17Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 75-year-old woman has severe symptomatic mitral regurgitation with a flail posterior leaflet and normal left ventricular function. Which repair technique is most appropriate?

  1. Mitral valve replacement with a mechanical prosthesis
  2. Aortic valve replacement
  3. Commissurotomy
  4. Posterior leaflet resection with annuloplasty ring Correct answer.

Explanation

Degenerative mitral regurgitation from a flail posterior leaflet is best treated by leaflet resection and annuloplasty, which has excellent durability and avoids anticoagulation.

Question 18Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient with constrictive pericarditis has equalisation of diastolic pressures and a characteristic septal bounce. Which imaging modality best demonstrates the thickened pericardium and diastolic septal motion?

  1. Abdominal ultrasound
  2. Chest radiography
  3. Transthoracic echocardiography Correct answer.
  4. Coronary angiography

Explanation

Echocardiography demonstrates pericardial thickening, respiratory variation in mitral inflow, and septal bounce in constrictive pericarditis. It is the first-line functional imaging test.

Question 19Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient is scheduled for elective coronary artery bypass grafting while taking clopidogrel after recent stenting. Which management plan best balances bleeding and stent thrombosis risk?

  1. Stop clopidogrel on the morning of surgery only
  2. Continue clopidogrel until the day of surgery
  3. Stop clopidogrel about five days before surgery if the stent is not recent Correct answer.
  4. Double the clopidogrel dose before surgery

Explanation

Clopidogrel is typically withheld about five days before elective surgery to allow platelet function recovery while balancing stent thrombosis risk. The timing depends on stent type and urgency.

Question 20Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient develops low cardiac output after mitral valve replacement with a pulmonary artery diastolic pressure of 28 mmHg and a low wedge pressure. Which cause should be excluded first?

  1. Right ventricular failure or pulmonary hypertension Correct answer.
  2. Left atrial appendage thrombosis
  3. Systemic hypertension
  4. Aortic stenosis

Explanation

A high pulmonary artery diastolic pressure with a low wedge pressure suggests right ventricular dysfunction or elevated pulmonary vascular resistance. Right ventricular failure is a common cause of low output after mitral surgery.

Question 21Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 68-year-old man with a history of mediastinal irradiation presents with severe aortic stenosis and a heavily calcified annulus. Which consideration most affects the choice between surgical and transcatheter intervention?

  1. Estimated operative risk and annular calcification extent Correct answer.
  2. Serum uric acid level
  3. Presence of varicose veins
  4. Patient's blood group

Explanation

Operative risk scores and the extent of annular calcification influence whether surgery or transcatheter implantation is safer. Severe annular calcification increases the risk of annular rupture and paravalvular leak.

Question 22Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient has a mechanical aortic valve and requires urgent surgery for a fractured femur. Which perioperative strategy is safest?

  1. Bridge with intravenous heparin while warfarin is withheld Correct answer.
  2. Continue warfarin and proceed with surgery
  3. Switch to aspirin alone
  4. Stop warfarin and give no bridging

Explanation

For urgent non-cardiac surgery in a patient with a mechanical valve, warfarin is withheld and bridging with intravenous heparin maintains anticoagulation until surgery. This balances bleeding and thromboembolic risk.

Question 23Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 60-year-old man with a bicuspid aortic valve develops a 5.5 cm ascending aortic aneurysm. Which statement best guides the operative decision?

  1. Aneurysm size alone determines the need for surgery regardless of valve function
  2. Aortic replacement is never indicated with a bicuspid valve
  3. Valve replacement alone is sufficient
  4. Concomitant aortic replacement is recommended when the ascending aorta exceeds 5.0 to 5.5 cm Correct answer.

Explanation

In bicuspid aortopathy, ascending aortic replacement is generally recommended when the diameter reaches about 5.0 to 5.5 cm, depending on risk factors. Leaving a dilated aorta untreated risks dissection.

Question 24Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient in cardiogenic shock after acute myocardial infarction has a ventricular septal rupture. Which management sequence is most appropriate?

  1. Pericardiocentesis
  2. Thrombolysis
  3. Prolonged medical therapy for six weeks before surgery
  4. Immediate surgical repair after stabilisation with mechanical support Correct answer.

Explanation

Ventricular septal rupture after infarction is a mechanical emergency requiring urgent surgical repair, often with mechanical circulatory support to stabilise haemodynamics. Delay increases mortality.

Question 25Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient with a large left ventricular aneurysm after anterior infarction has heart failure and ventricular arrhythmias. Which operation addresses both the aneurysm and the arrhythmia substrate?

  1. Aortic valve replacement
  2. Coronary sinus ligation
  3. Pericardiectomy
  4. Left ventricular aneurysmectomy with endocardial cryoablation Correct answer.

Explanation

Aneurysmectomy with endocardial cryoablation removes the dyskinetic segment and the arrhythmogenic border zone. This improves ventricular geometry and reduces arrhythmia burden.

Question 26Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 58-year-old man undergoes elective coronary artery bypass grafting. Which intraoperative measurement of graft flow is most useful for confirming that an individual bypass graft is functioning adequately before chest closure?

  1. Intraoperative epicardial echocardiography of the graft conduit
  2. Transit-time flow measurement with a mean graft flow above 15 mL/min and low pulsatility index Correct answer.
  3. Pressure gradient across the anastomosis using a 22-gauge needle and transducer
  4. Measurement of coronary sinus oxygen saturation before and after graft opening

Explanation

Transit-time flowmetry is the standard intraoperative method for assessing individual graft function; a mean flow above roughly 15 mL/min with a pulsatility index below about 3 suggests an adequate graft, and a high pulsatility index with low flow prompts revision. Epicardial echocardiography has poor resolution for distal anastomoses, coronary sinus saturation reflects global rather than single-graft perfusion, and direct needle pressure measurement is rarely practical and risks the anastomosis.

Question 27Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which finding on transthoracic echocardiography is most specific for cardiac tamponade in a patient with a large pericardial effusion after cardiac surgery?

  1. Moderate mitral annular calcification
  2. Right ventricular diastolic collapse Correct answer.
  3. Left atrial enlargement greater than 4.5 cm
  4. Left ventricular ejection fraction below 40 percent

Explanation

Right ventricular diastolic collapse occurs when intrapericardial pressure exceeds right ventricular diastolic pressure and is a specific sign of tamponade physiology. Reduced ejection fraction, mitral annular calcification and left atrial enlargement are unrelated to the haemodynamic effect of the effusion.

Question 28Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 64-year-old woman with severe symptomatic aortic stenosis and a normal coronary anatomy is scheduled for surgical aortic valve replacement. Which prosthesis-related consideration most strongly favours a mechanical valve over a bioprosthesis in this patient?

  1. She has mild renal impairment with a creatinine of 130 micromol/L
  2. She has paroxysmal atrial fibrillation documented on Holter monitoring
  3. She has a history of treated breast cancer ten years earlier
  4. She is 64 years old and has no contraindication to long-term anticoagulation Correct answer.

Explanation

Age and the ability to tolerate long-term anticoagulation are the dominant factors in prosthesis selection; current guidance generally favours a mechanical valve in patients under about 65 years who can take vitamin K antagonists safely. Renal impairment, remote treated malignancy and paroxysmal atrial fibrillation are not decisive selection criteria.

Question 29Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

During repair of an acute type A aortic dissection, which principle best guides the extent of proximal aortic resection?

  1. Replace the ascending aorta only when the aortic valve is regurgitant
  2. Leave the aortic root untouched to shorten cross-clamp time regardless of the entry tear
  3. Preserve or resect the root according to the status of the aortic sinuses and valve, aiming to obliterate the false lumen proximally Correct answer.
  4. Resect all dissected tissue and replace the entire root in every patient

Explanation

Proximal repair is tailored to the individual: the root is preserved when sinuses are intact and the valve is competent, and replaced when the sinuses are destroyed or the valve cannot be repaired, always aiming to eliminate the proximal entry tear and false lumen. Routine total root replacement increases operative risk without proven benefit, and leaving a proximal entry tear untreated predisposes to reoperation and false-lumen expansion.

Question 30Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient with a mechanical aortic valve has a supra-therapeutic INR of 6.5 after starting a course of antibiotics but has no bleeding. Which management step is most appropriate?

  1. Continue the current warfarin dose and recheck the INR in one week
  2. Omit warfarin, give vitamin K 2.5 mg orally and recheck the INR in 24 hours Correct answer.
  3. Stop warfarin permanently and switch to a direct oral anticoagulant
  4. Give fresh frozen plasma immediately and restart warfarin at a lower dose

Explanation

For an INR above 6 without bleeding, guidance is to withhold warfarin and give low-dose oral vitamin K, then recheck the INR within a day; this reduces bleeding risk without causing valve thrombosis. Continuing the same dose risks further elevation, fresh frozen plasma is reserved for major bleeding, and direct oral anticoagulants are contraindicated with mechanical valves.

Question 31Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which statement best describes the mechanism of functional mitral regurgitation in a patient with dilated cardiomyopathy and a normal mitral valve?

  1. Leaflet perforation from previous endocarditis
  2. Vegetation on the anterior leaflet causing leaflet destruction
  3. Annular dilatation and tethering of structurally normal leaflets by displaced papillary muscles Correct answer.
  4. Rupture of the posterior chordae tendineae

Explanation

Functional mitral regurgitation results from ventricular remodelling: annular dilatation and outward displacement of the papillary muscles tether otherwise normal leaflets, restricting coaptation. Leaflet perforation, chordal rupture and vegetations are structural causes of organic regurgitation.

Question 32Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 72-year-old man with severe aortic stenosis and a hostile chest from prior radiotherapy is discussed at the heart team. Which finding would most strongly support transcatheter over surgical aortic valve replacement in this patient?

  1. A Society of Thoracic Surgeons predicted risk of mortality above 8 percent and a hostile mediastinum Correct answer.
  2. An aortic annulus diameter of 26 mm on computed tomography
  3. Aortic valve area of 0.8 cm squared with a mean gradient of 45 mm Hg
  4. A bicuspid aortic valve with heavy calcification of both cusps

Explanation

Heart-team decisions favour transcatheter aortic valve implantation when surgical risk is high and when the chest is hostile, because re-entry and dissection risks at reoperation are substantial. Bicuspid anatomy with heavy calcification, annular size and the severity of stenosis influence technical planning but do not by themselves favour a transcatheter approach.

Question 33Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which finding is most consistent with a diagnosis of constrictive pericarditis rather than restrictive cardiomyopathy?

  1. Marked biatrial enlargement with normal ventricular wall thickness
  2. Left ventricular wall thickness of 18 mm with a low-voltage electrocardiogram
  3. Annulus paradoxus with preserved or increased medial mitral annular velocity Correct answer.
  4. Severe left ventricular hypertrophy with a restrictive filling pattern

Explanation

In constrictive pericarditis, ventricular filling is limited by the pericardium, so medial mitral annular velocity is typically preserved or increased, producing annulus paradoxus, and ventricular wall thickness is normal. Marked hypertrophy, low voltage with thick walls and severe hypertrophy with restrictive filling point towards infiltrative or restrictive myocardial disease.

Question 34Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient has a large, loculated posterior pericardial effusion with early tamponade physiology after a recent cardiac operation. Which drainage approach is most appropriate?

  1. Percutaneous pericardiocentesis using an anterior approach
  2. Subxiphoid pericardial window under local anaesthesia Correct answer.
  3. Left anterior thoracotomy with pericardial window
  4. Observation with serial echocardiography and diuretics

Explanation

A subxiphoid pericardial window allows controlled drainage of loculated or posterior effusions and permits a tissue window to prevent recurrence, which is valuable after cardiac surgery. Blind anterior pericardiocentesis risks injury to adherent structures and may not reach a posterior loculation, and observation is unsafe with tamponade physiology.

Question 35Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which coronary artery lesion is most likely to cause acute severe mitral regurgitation with pulmonary oedema in a patient with an inferior myocardial infarction?

  1. Proximal left anterior descending artery occlusion
  2. Occlusion of a dominant right coronary artery or circumflex branch supplying the posteromedial papillary muscle Correct answer.
  3. Occlusion of the left main coronary artery
  4. Occlusion of a small diagonal branch

Explanation

The posteromedial papillary muscle has a single blood supply from the posterior descending artery, usually arising from a dominant right coronary or circumflex artery, so occlusion causes papillary muscle rupture and acute mitral regurgitation. The anterolateral papillary muscle has a dual supply and is less vulnerable, and left main or diagonal occlusion produces different patterns of infarction.

Question 36Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which of the following is the most appropriate initial step in managing a patient with a suspected acute prosthetic valve thrombosis who is haemodynamically stable with a small thrombus on fluoroscopy?

  1. Fibrinolytic therapy with alteplase
  2. Intravenous unfractionated heparin with a target activated partial thromboplastin time of 1.5 to 2 times control Correct answer.
  3. Aspirin 300 mg daily alone
  4. Immediate redo valve replacement

Explanation

In a stable patient with a small thrombus, initial treatment is therapeutic intravenous unfractionated heparin with careful monitoring, followed by reassessment of valve function. Fibrinolysis is reserved for unstable patients or those with larger thrombi, surgery is considered when heparin fails or the patient deteriorates, and aspirin alone is inadequate.

Question 37Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which statement best describes the rationale for using the internal thoracic artery in coronary revascularisation?

  1. It is easier to harvest than the radial artery
  2. It has a lower incidence of intimal hyperplasia and atherosclerosis than vein grafts Correct answer.
  3. It can be used only for right-sided coronary targets
  4. It has a higher early flow than any vein graft

Explanation

The internal thoracic artery has an intact endothelial layer and a lower tendency to develop intimal hyperplasia and atherosclerosis, which underlies its superior long-term patency compared with saphenous vein grafts. Its early flow may be lower than a vein graft, it is not necessarily easier to harvest, and it is used mainly for left-sided targets.

Question 38Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient with severe mitral stenosis in sinus rhythm is undergoing balloon mitral valvuloplasty. Which echocardiographic feature most strongly predicts a good procedural result?

  1. A Wilkins score of 12 with heavy leaflet calcification
  2. A left atrial thrombus seen on transoesophageal echocardiography
  3. A Wilkins score of 6 with thin, mobile leaflets and minimal commissural calcification Correct answer.
  4. Moderate-to-severe mitral regurgitation before the procedure

Explanation

A low Wilkins score indicates pliable, minimally calcified leaflets with limited subvalvular disease, which predicts successful commissural splitting. A high score, significant pre-existing regurgitation and left atrial thrombus are relative contraindications because they increase the risk of failure or complications.

Question 39Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which intraoperative strategy best reduces the risk of stroke during coronary artery bypass grafting in a patient with a mobile atheroma in the ascending aorta detected on epiaortic ultrasound?

  1. Clamp the aorta at the site of the atheroma to stabilise it
  2. Avoid aortic clamping and use off-pump or no-touch techniques with alternative proximal graft sources Correct answer.
  3. Use a single cross-clamp and perform all proximal anastomoses under it
  4. Increase the systemic blood pressure during clamping

Explanation

A mobile atheroma is a strong risk factor for embolic stroke, so the ascending aorta should be avoided entirely using off-pump or no-touch techniques, with inflow from the internal thoracic arteries or axillary artery. Clamping at or near the atheroma, whether single or multiple, risks dislodgement, and raising pressure does not protect against embolisation.

Question 40Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which finding on coronary angiography most strongly indicates that a coronary lesion is physiologically significant when the fractional flow reserve is not available?

  1. A 90 percent diameter stenosis with a corresponding perfusion defect on stress imaging Correct answer.
  2. A 50 percent stenosis with a negative exercise tolerance test
  3. A 60 percent diameter stenosis in a large proximal vessel
  4. A 70 percent stenosis in a vessel supplying an akinetic territory

Explanation

A very severe stenosis with a matching reversible perfusion defect provides strong evidence of ischaemia and justifies revascularisation. Moderate stenoses without ischaemic evidence, and stenoses supplying infarcted non-viable myocardium, are less likely to benefit from grafting.

Question 41Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A patient develops sudden hypotension and a new continuous murmur on the second day after aortic root replacement with a composite graft. Which complication is most likely?

  1. Left ventricular failure from myocardial infarction
  2. Acute prosthetic valve endocarditis
  3. Rupture of the right coronary button anastomosis with a pseudoaneurysm Correct answer.
  4. Cardiac tamponade from a pleural effusion

Explanation

A new continuous murmur with hypotension early after a button-modified Bentall procedure suggests dehiscence or rupture of a coronary button anastomosis, creating a false aneurysm or fistula. Endocarditis is unlikely within two days, and tamponade and ventricular failure do not produce a continuous murmur.

Question 42Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which of the following best explains why the radial artery is increasingly used as a second arterial conduit in coronary surgery?

  1. It can be harvested without any risk of hand ischaemia
  2. It has a thicker muscular wall and is less prone to spasm than the internal thoracic artery
  3. It is the only conduit suitable for sequential grafting
  4. It shows better long-term patency than saphenous vein grafts when used for severe stenoses in non-left anterior descending targets Correct answer.

Explanation

Randomised evidence indicates that the radial artery has better long-term patency than saphenous vein grafts, particularly when grafted to severely stenotic non-left anterior descending targets, and it is therefore used as a second arterial conduit. It is more prone to spasm than the internal thoracic artery, hand ischaemia is a recognised but uncommon risk, and sequential grafting is possible with several conduits.

Question 43Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

A 45-year-old woman with a mechanical mitral valve becomes pregnant. Which anticoagulation strategy is most appropriate during the first trimester?

  1. Warfarin at a dose that keeps the INR between 2.5 and 3.5 throughout pregnancy
  2. Aspirin 100 mg daily alone
  3. Direct oral anticoagulant therapy
  4. Low molecular weight heparin with dose adjustment according to anti-Xa levels Correct answer.

Explanation

Warfarin is teratogenic in the first trimester, so guidelines recommend replacing it with adjusted-dose low molecular weight heparin, monitored by anti-Xa levels or peak anti-factor Xa activity, during organogenesis. Warfarin may be considered later in pregnancy in selected patients, aspirin alone is inadequate for a mechanical valve, and direct oral anticoagulants are contraindicated.

Question 44Cardiac Surgery – Adult Acquired (coronary, valvular, aortic, pericardial)

Which of the following best describes the haemodynamic consequence of a large left-to-right shunt through a post-infarction ventricular septal rupture?

  1. Obstruction of the left ventricular outflow tract
  2. Right-to-left shunting with systemic desaturation
  3. Isolated left ventricular volume overload with preserved systemic output
  4. Increased right ventricular volume load with pulmonary congestion and reduced systemic output Correct answer.

Explanation

Blood shunts from the high-pressure left ventricle to the low-pressure right ventricle, increasing pulmonary blood flow and right ventricular volume load while reducing forward systemic output, which produces pulmonary oedema and cardiogenic shock. Shunting is left-to-right, not right-to-left, and the outflow tract is not obstructed.

Question 45Thoracic Surgery – Pulmonary, Pleural, Chest Wall and Diaphragm

A 24-year-old man sustains blunt chest trauma in a road traffic collision. He becomes progressively breathless and hypotensive. On examination, the trachea is deviated to the left, the right hemithorax is hyper-resonant with absent breath sounds, and neck veins are distended. What is the most appropriate immediate management?

  1. Urgent CT scan of the chest before any intervention
  2. Immediate right-sided tube thoracostomy in the second intercostal space in the midclavicular line
  3. Emergency intubation and positive pressure ventilation before drainage
  4. Immediate needle decompression followed by chest drain insertion Correct answer.

Explanation

The clinical picture is a right-sided tension pneumothorax with obstructive shock. Needle decompression must precede definitive tube thoracostomy, and drainage must never be delayed for imaging. Positive pressure ventilation before decompression will worsen the tension physiology.

Question 46Thoracic Surgery – Pulmonary, Pleural, Chest Wall and Diaphragm

Which finding on chest radiography most reliably indicates that a chest drain has been correctly positioned for drainage of a free pleural effusion?

  1. The drain tip is directed cephalad toward the apex
  2. The drain tip lies within the pleural fluid shadow at the lung base Correct answer.
  3. The drain tip is seen overlying the gastric bubble
  4. The drain is seen coiling in the subcutaneous tissues

Explanation

For a free effusion the drain should be sited with its tip in the dependent fluid collection at the base, typically via a lower intercostal space. Cephalad direction is appropriate for pneumothorax, not effusion. Subcutaneous coiling and gastric overlying indicate malposition.

Question 47Thoracic Surgery – Pulmonary, Pleural, Chest Wall and Diaphragm

A patient develops a persistent air leak and a large residual space after lobectomy. Which of the following is the most appropriate initial conservative measure?

  1. Immediate rethoracotomy and completion pneumonectomy
  2. Application of low-pressure suction to the chest drain with physiotherapy Correct answer.
  3. Chemical pleurodesis through the drain on day one
  4. Clamping the chest drain to encourage lung expansion

Explanation

Persistent air leak with residual space is initially managed conservatively with controlled low-pressure suction, physiotherapy, and mobilization to encourage lung re-expansion. Early reoperation and pleurodesis are reserved for failure of conservative management. Clamping a drain in the presence of an air leak risks tension pneumothorax.

Question 48Thoracic Surgery – Pulmonary, Pleural, Chest Wall and Diaphragm

Which statement about the arterial supply of the thoracic wall is correct?

  1. The supreme intercostal artery arises from the thyrocervical trunk
  2. The posterior intercostal arteries arise directly from the internal thoracic artery
  3. The internal thoracic artery arises from the subclavian artery and gives anterior intercostal branches Correct answer.
  4. The anterior intercostal arteries arise from the descending thoracic aorta

Explanation

The internal thoracic artery is a branch of the subclavian and supplies anterior intercostal arteries. Posterior intercostal arteries arise from the descending thoracic aorta, and the supreme intercostal artery arises from the costocervical trunk.

Question 49Thoracic Surgery – Pulmonary, Pleural, Chest Wall and Diaphragm

A 55-year-old smoker presents with a solitary pulmonary nodule measuring 9 mm on CT, with smooth margins and no calcification. What is the most appropriate next step?

  1. Empirical antibiotic therapy followed by repeat imaging in three months
  2. Immediate surgical resection by wedge excision
  3. Repeat CT surveillance according to a defined nodule follow-up protocol Correct answer.
  4. Percutaneous needle biopsy of the nodule

Explanation

A small indeterminate nodule below the threshold for immediate intervention is best managed by serial CT surveillance following a structured protocol, guided by risk factors. Biopsy and resection are reserved for nodules that grow, are larger, or have high-risk features.

Question 50Thoracic Surgery – Pulmonary, Pleural, Chest Wall and Diaphragm

Which of the following best describes the anatomical boundaries of the thoracic inlet?

  1. Twelfth thoracic vertebra, twelfth ribs, and the costal margin
  2. First thoracic vertebra, first ribs and their costal cartilages, and the manubrium Correct answer.
  3. Second thoracic vertebra, second ribs, and the sternal angle
  4. Tenth thoracic vertebra, costal margin, and xiphoid process

Explanation

The thoracic inlet is bounded by the first thoracic vertebra posteriorly, the first ribs and their costal cartilages laterally, and the manubrium anteriorly. The thoracic outlet (diaphragmatic) is bounded by the costal margin, lower ribs, and xiphoid.