Iraqi Board Thoracic & Cardiovascular Surgery cheat sheet

Coronary artery bypass grafting: left internal thoracic artery to left anterior descending artery is the reference conduit; arterial grafts show higher long-term patency than saphenous vein grafts.

Society of Thoracic Surgeons (STS) risk score predicts operative mortality using age, renal function, ejection fraction, urgency, reoperation, and comorbidities; it is used for shared decision-making, not as a sole exclusion criterion.

Aortic stenosis with symptoms or left ventricular ejection fraction below 50% is a class I indication for aortic valve replacement; asymptomatic severe stenosis warrants intervention when exercise testing is abnormal or the ventricle decompensates.

Degenerative mitral regurgitation: repair is preferred to replacement when durable repair is feasible, because it preserves the subvalvular apparatus and left ventricular function.

Acute type A aortic dissection is a surgical emergency; the operation targets the ascending aorta and root, with aortic valve resuspension preferred when leaflets are structurally normal.

Pericardial effusion with tamponade physiology (pulsus paradoxus, electrical alternans, diastolic collapse on echocardiography) requires urgent drainage; medical therapy alone is not definitive.

Cardiopulmonary bypass induces a systemic inflammatory response and coagulopathy; heparin is monitored by activated clotting time, and protamine reverses heparin at separation from bypass.

Postoperative atrial fibrillation after cardiac surgery occurs in roughly 20–40% of patients; rate control plus electrolyte correction is first-line, with anticoagulation decided individually.

Lung cancer resection: lobectomy with systematic nodal dissection is the standard for resectable non-small cell lung cancer; sublobar resection is reserved for limited reserve or small peripheral lesions.

Anatomic lung segments are defined by their segmental bronchi; the right lung has 10 segments and the left has 8–10 depending on whether the subsuperior segment is counted.

Spontaneous pneumothorax management: small asymptomatic primary cases may be observed; large or symptomatic cases need aspiration or tube thoracostomy, and recurrence or persistent air leak suggests blebectomy with pleurodesis.

Malignant pleural effusion is best managed by indwelling pleural catheter or talc pleurodesis when lung re-expansion is adequate; trapped lung favors a catheter.

Flail chest with respiratory failure is an indication for surgical rib fixation, which reduces ventilator days and pneumonia in selected patients.

Diaphragmatic paralysis is diagnosed by sniff test or ultrasound; unilateral paralysis is often tolerated, while bilateral paralysis causes orthopnea and hypercapnia.

Chest drain removal criteria include absence of air leak, drainage below a defined threshold, and radiographic lung expansion; clamping before removal is not routinely required.

Empyema is staged by the American Thoracic Society system (exudative, fibrinopurulent, organizing); late organizing stage may require decortication.

Ventricular septal defect: restrictive defects may close spontaneously; large defects cause heart failure and failure to thrive and require surgical or device closure.

Tetralogy of Fallot comprises ventricular septal defect, overriding aorta, right ventricular outflow obstruction, and right ventricular hypertrophy; repair relieves the outflow obstruction and closes the defect.

Transposition of the great arteries with an intact ventricular septum is corrected by the arterial switch operation within the first weeks of life; prostaglandin E1 maintains ductal patency preoperatively.

Ductus arteriosus-dependent lesions (critical coarctation, pulmonary atresia, interrupted arch) require prostaglandin E1 infusion to preserve systemic or pulmonary blood flow.

Fontan circulation is a staged palliation for single-ventricle physiology; the total cavopulmonary connection is performed when pulmonary vascular resistance is low, typically in early childhood.

Aortopulmonary collaterals and pulmonary hypertension are assessed before single-ventricle completion; elevated pulmonary vascular resistance contraindicates the Fontan pathway.

Congenital heart surgery outcomes are described by the Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery (STAT) categories, which stratify operations by expected mortality.

Abdominal aortic aneurysm repair is indicated at diameter ≥5.5 cm in men or ≥5.0 cm in women, or when growth exceeds 1 cm per year or symptoms develop.

Ruptured abdominal aortic aneurysm presents with the triad of hypotension, back or abdominal pain, and a pulsatile mass; endovascular repair is preferred when anatomy permits.

Carotid endarterectomy is indicated for symptomatic severe stenosis (70–99%) and selected moderate stenosis; timing is ideally within 2 weeks of the index event.

Peripheral arterial disease severity is classified by the Rutherford or Fontaine systems; critical limb-threatening ischemia requires urgent revascularization.

Acute limb ischemia is classified by the Rutherford acute categories, and a threatened limb with motor deficit requires immediate revascularization.

Antiplatelet therapy (aspirin plus a P2Y12 inhibitor for a defined period) is standard after endovascular stenting; dual therapy duration depends on bleeding risk and stent type.

Endoleak after endovascular aneurysm repair is classified into types I–V; type I and III endoleaks require reintervention because of pressurization risk.

Lung cancer staging follows the tumor-node-metastasis (TNM) system; stage I–II disease is generally resectable, stage III is often multimodality, and stage IV is systemic therapy.

Mediastinal masses are anatomically divided into anterior, middle, and posterior compartments; anterior masses include thymoma, teratoma, thyroid, and lymphoma.

Thymoma is associated with myasthenia gravis in about one third of patients; complete thymectomy is the mainstay of treatment.

Esophageal cancer: adenocarcinoma arises in Barrett esophagus and distal esophagus, while squamous cell carcinoma predominates in the upper and middle esophagus.

Esophageal resection typically requires lymphadenectomy and reconstruction with a gastric conduit; neoadjuvant chemoradiation improves survival in locally advanced disease.

Tracheal tumors and stenosis are evaluated by bronchoscopy and computed tomography; resection with primary anastomosis is limited to a small proportion of the tracheal length.

Malignant pleural mesothelioma is associated with asbestos exposure; histologic subtypes (epithelioid, sarcomatoid, biphasic) determine prognosis.

Low cardiac output syndrome after cardiac surgery is managed with inotropes, vasopressors, and afterload reduction; mixed venous oxygen saturation and lactate guide therapy.

Acute respiratory distress syndrome is defined by the Berlin criteria: onset within one week, bilateral infiltrates, no cardiac cause, and a PaO2/FiO2 ratio below 300.

Sepsis is defined by suspected infection plus organ dysfunction; the Surviving Sepsis Campaign recommends early antibiotics and fluid resuscitation.

Acute kidney injury is staged by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria using serum creatinine rise and urine output.

Delirium after cardiac surgery is common; the Confusion Assessment Method for the Intensive Care Unit is the standard screening tool.

Ventilator-associated pneumonia is diagnosed by new infiltrates, fever, and purulent secretions after 48 hours of ventilation; prevention includes head elevation and daily sedation interruption.

Transfusion thresholds in most critically ill patients follow restrictive strategies (hemoglobin around 7–8 g/dL), with exceptions for active bleeding or myocardial ischemia.

Cardiopulmonary bypass requires systemic anticoagulation; activated clotting time is typically maintained above 400–480 seconds during bypass.

Extracorporeal membrane oxygenation (ECMO) modes: venovenous supports oxygenation, while venoarterial supports both cardiac and pulmonary function.

Left ventricular assist device (LVAD) patients require anticoagulation and infection control; pump thrombosis presents with hemolysis, elevated lactate dehydrogenase, and power spikes.

Right ventricular failure after LVAD implantation is managed with pulmonary vasodilators and inotropes; severe cases may require temporary right ventricular support.

Intra-aortic balloon counterpulsation augments diastolic coronary perfusion and reduces afterload; contraindications include severe aortic regurgitation and aortic dissection.

Transesophageal echocardiography guides cannulation, de-airing, and valve assessment during cardiac surgery.

Anesthetic induction in cardiac patients accounts for hemodynamic goals: maintain coronary perfusion and avoid tachycardia in aortic stenosis and ischemia.

Computed tomography pulmonary angiography is the first-line test for suspected pulmonary embolism in stable patients.

Coronary computed tomography angiography has high negative predictive value in low-to-intermediate risk chest pain but is limited by calcification and arrhythmia.

Transthoracic echocardiography is first-line for valve disease and pericardial effusion; transesophageal echocardiography is superior for prosthetic valves and endocarditis.

Magnetic resonance imaging is the reference standard for myocardial viability and infiltrative disease, though it is avoided in patients with non-compatible implants.

Chest radiograph findings of widened mediastinum or abnormal contour after trauma prompt computed tomography angiography for aortic injury.

Positron emission tomography with fluorodeoxyglucose improves staging of lung cancer and assessment of mediastinal lymph nodes.

Aortic dissection is diagnosed by computed tomography angiography showing an intimal flap and true and false lumens.

Fractional flow reserve below 0.80 identifies hemodynamically significant coronary stenosis and supports revascularization.

Coronary angiography defines anatomy and guides revascularization strategy; SYNTAX score quantifies complexity in multivessel disease.

Acute coronary syndrome: ST-elevation myocardial infarction requires primary percutaneous coronary intervention within 90 minutes of first medical contact when feasible.

Dual antiplatelet therapy duration after drug-eluting stent placement depends on ischemic and bleeding risk; premature discontinuation risks stent thrombosis.

Heart failure with reduced ejection fraction benefits from guideline-directed medical therapy: renin-angiotensin system inhibition, beta-blockade, mineralocorticoid antagonism, and SGLT2 inhibition.

Aortic stenosis severity is graded by mean gradient, peak velocity, and valve area; low-flow low-gradient states require dobutamine stress echocardiography.

Pulmonary hypertension is classified by the World Health Organization groups I–V, and group I disease is treated with pulmonary vasodilators.

The coronary circulation is dominant right in about 85% of people; dominance is defined by which artery supplies the posterior descending artery.

The cardiac cycle: systole includes isovolumetric contraction and ejection; diastole includes isovolumetric relaxation and filling, with coronary flow predominantly diastolic.

Frank–Starling relationship: increasing preload increases stroke volume within physiologic limits; excessive preload causes pulmonary congestion.

Oxygen delivery equals cardiac output multiplied by arterial oxygen content; oxygen content equals 1.34 × hemoglobin × saturation plus dissolved oxygen.

The phrenic nerve (C3–C5) supplies the diaphragm; the recurrent laryngeal nerve loops around the aortic arch on the left and the subclavian artery on the right.

Warfarin inhibits vitamin K epoxide reductase and affects factors II, VII, IX, and X; heparin potentiates antithrombin III.

Pressure–volume loop: the area within the loop represents stroke work, and the end-systolic pressure–volume relationship reflects contractility.

Proximal anastomosis of saphenous vein grafts is performed with an aortic side-biting clamp or a no-touch technique; the left internal thoracic artery is anastomosed to the left anterior descending artery.

Bioprosthetic valves are preferred in older patients and those with contraindications to anticoagulation; mechanical valves require lifelong anticoagulation.

Prosthetic graft material is selected by infection risk and location: polytetrafluoroethylene and Dacron are standard for vascular reconstruction.

Aortic root replacement with a composite graft (Bentall procedure) replaces the aortic valve and ascending aorta; valve-sparing root replacement preserves the native valve.

Suture materials: polypropylene for vascular anastomoses, polydioxanone for slow-absorbing soft tissue closure.

Cardiopulmonary bypass circuits require heparin-coated surfaces or systemic anticoagulation to prevent thrombus formation.

Tissue valve degeneration and mechanical valve thrombosis are major late complications; echocardiography surveillance is required for both.

Surgical site infection prevention includes preoperative antibiotic prophylaxis within 60 minutes of incision, normothermia, and glucose control.

Sternal wound infection is classified by depth: superficial, deep sternal, and mediastinitis; mediastinitis requires debridement and reconstruction.

Central line–associated bloodstream infection prevention includes chlorhexidine skin antisepsis and prompt removal of unnecessary catheters.

Hand hygiene remains the single most effective measure to reduce hospital-acquired infection.

The World Health Organization surgical safety checklist reduces morbidity and mortality by standardizing team communication.

Antimicrobial stewardship reduces resistance; de-escalation based on culture results is recommended.

Needlestick injury: immediate washing, reporting, and post-exposure prophylaxis assessment for hepatitis B, hepatitis C, and HIV.

Randomized controlled trials provide the strongest evidence for causal treatment effects; observational studies are vulnerable to confounding.

Levels of evidence and grades of recommendation are graded by systems such as GRADE, which separates quality of evidence from strength of recommendation.

Sensitivity is the proportion of true positives detected; specificity is the proportion of true negatives detected.

Positive predictive value depends on disease prevalence, while sensitivity and specificity do not.

A p-value below 0.05 indicates statistical significance, not clinical importance; effect size and confidence intervals should be reported.

Number needed to treat is the reciprocal of absolute risk reduction.

Meta-analysis pools study estimates; heterogeneity is assessed with the I² statistic and Cochran Q test.

Informed consent requires capacity, disclosure of risks, benefits, and alternatives, and voluntary decision-making.

Emergency exception permits treatment without consent when the patient lacks capacity and delay would cause harm.

Confidentiality may be breached when required by law or when there is a serious risk to others.

Conflicts of interest must be disclosed and managed; financial relationships with industry should not influence clinical decisions.

Research ethics require institutional review board approval, informed consent, and equipoise for randomized trials.

Futility and goals-of-care discussions should involve the patient or surrogate and the multidisciplinary team.

Professional misconduct includes falsification of records, boundary violations, and practicing outside competence.