Mixed Deck — All CSC Topics Flashcards

What is the typical target mean arterial pressure (MAP) during cardiopulmonary bypass for most adult patients?

Answer: 50–80 mmHg

A MAP of 50–80 mmHg is generally maintained during CPB to ensure adequate end-organ perfusion while minimizing bleeding risk.

Deep hypothermic circulatory arrest (DHCA) is used in aortic arch surgery primarily to:

Answer: Provide a bloodless operative field while protecting the brain and organs during circulatory pause

DHCA cools the patient to 15–20°C, dramatically reducing cerebral metabolic demand and allowing safe cessation of circulation for arch reconstruction.

Systolic blood pressure that is higher than average is a sign of abnormal pulsus paradoxus.

Answer: More than 10 mm Hg lower during inhalation than exhalation

Systolic blood pressure that is noticeably lower during intake than expiration is known as pulsus paradoxus. A pulsus paradoxus with a difference of more than 10 mm Hg is regarded as abnormal and is frequently a symptom of cardiac tamponade. It is normal to experience a drop in blood pressure of 10 mm Hg or less during inspiration, but a larger pressure difference could be a sign of various cardiopulmonary complications, such as pericardial effusion, pericarditis, pulmonary embolism, cardiogenic shock, chronic obstructive pulmonary disease, asthma, and obstruction of the superior vena cava. If pulsus paradoxus is discovered, blood pressure data should be reassessed to guarantee accuracy.

Emergency CABG is most commonly indicated after failed PCI in the setting of:

Answer: Acute coronary occlusion with hemodynamic compromise unresponsive to catheter-based intervention

Emergency surgical revascularization is indicated when PCI fails to restore flow and ongoing ischemia with hemodynamic instability persists, requiring immediate coronary bypass.

Intraoperative graft flow measurement using transit-time flowmetry is used to:

Answer: Verify graft patency and detect technical errors before chest closure

Transit-time flowmetry measures actual blood flow through each graft, identifying low-flow or pulsatility index abnormalities suggesting technical problems requiring revision.

What is the purpose of a left ventricular vent during cardiopulmonary bypass?

Answer: To prevent left ventricular distension and reduce myocardial work

The LV vent decompresses the left ventricle, preventing distension that can cause myocardial injury when the heart is arrested.

Neurological complications after cardiac surgery, including stroke, are most often caused by:

Answer: Cerebral embolism from atheromatous aortic debris or air

Macroemboli from atheromatous aortic plaque dislodged during cannulation/clamping and air introduced during bypass are the leading causes of perioperative stroke.

During minimally invasive mitral valve surgery via right mini-thoracotomy, what is the preferred method of aortic occlusion when the surgeon cannot reach the ascending aorta directly?

Answer: Endoaortic balloon occlusion catheter

An endoaortic balloon occlusion catheter (Heartport) placed via the femoral artery allows intraluminal aortic occlusion and antegrade cardioplegia delivery without direct aortic cross-clamping.

Total anomalous pulmonary venous connection (TAPVC) requires urgent surgical repair when which condition is present?

Answer: Pulmonary venous obstruction causing severe cyanosis and pulmonary edema

Obstructed TAPVC is a surgical emergency because pulmonary venous obstruction causes severe pulmonary edema, profound hypoxemia, and cardiovascular collapse without urgent repair.

Intraoperative TEE after mitral valve repair is used primarily to:

Answer: Assess residual regurgitation and confirm adequate valve function before chest closure

Post-repair TEE immediately identifies residual or new regurgitation, stenosis, or systolic anterior motion, allowing the surgeon to revise the repair before leaving the OR.

What is the primary purpose of pulmonary artery banding as a palliative procedure in congenital heart surgery?

Answer: To restrict excessive pulmonary blood flow and protect pulmonary vasculature from hypertensive injury

Pulmonary artery banding reduces pulmonary blood flow and pressure in defects with excessive left-to-right shunting, protecting the pulmonary vasculature from progressive hypertensive obstructive disease.

The classic Blalock-Taussig (BT) shunt anastomoses which two structures?

Answer: Subclavian artery to ipsilateral pulmonary artery

The classic BT shunt connects the subclavian artery end-to-side to the ipsilateral pulmonary artery, increasing pulmonary blood flow in cyanotic congenital heart disease.

Which hemodynamic finding is characteristic of severe aortic stenosis requiring surgical intervention?

Answer: Mean aortic valve gradient greater than 40 mmHg with valve area less than 1.0 cm²

Severe AS is defined by a mean gradient >40 mmHg and aortic valve area <1.0 cm², indicating the need for intervention.

Systemic inflammatory response syndrome (SIRS) after CPB is primarily triggered by:

Answer: Contact activation from blood exposure to the bypass circuit

Contact of blood with the non-endothelial surfaces of the CPB circuit activates complement and inflammatory cascades, producing post-CPB SIRS.

A patient requires redo sternotomy for mitral valve replacement. What is the greatest risk during sternal re-entry?

Answer: Injury to adherent right ventricle

After prior cardiac surgery, the right ventricle commonly adheres to the posterior table of the sternum, making it vulnerable to laceration during oscillating saw re-entry.

What are the four components of Tetralogy of Fallot?

Answer: Ventricular septal defect, pulmonary stenosis, overriding aorta, and right ventricular hypertrophy

Tetralogy of Fallot consists of VSD, pulmonary stenosis (RVOTO), overriding aorta, and right ventricular hypertrophy — all resulting from anterosuperior displacement of the infundibular septum.

Which intraoperative monitoring is considered standard for major cardiac surgery requiring CPB?

Answer: Transesophageal echocardiography (TEE)

TEE is standard during cardiac surgery because it provides real-time assessment of cardiac function, valve repair quality, air removal, and filling status.

The Bentall procedure is performed for:

Answer: Aortic root aneurysm with aortic regurgitation, replacing the root, valve, and reimplanting coronary buttons

The Bentall procedure replaces the aortic root with a composite graft (valve + ascending aorta), with reimplantation of the coronary ostia as buttons into the graft.

The most common cause of mitral valve regurgitation requiring surgery in the United States is:

Answer: Myxomatous mitral valve disease (mitral valve prolapse)

Myxomatous degeneration (Barlow's disease or fibro-elastic deficiency) causing mitral valve prolapse is the leading cause of surgical mitral regurgitation in the US.

Stanford Type A aortic dissection requires emergency surgery primarily because of the risk of:

Answer: Pericardial tamponade, aortic regurgitation, and coronary ostial involvement

Type A dissection threatens the proximal aorta, risking rupture into the pericardium (tamponade), aortic valve disruption, and coronary ostial dissection causing acute MI.