Pre-operative cardiac risk assessment US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Pre-operative cardiac risk assessment. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Pre-operative cardiac risk assessment US Medical PG Question 1: A 70-year-old man with a recent above-the-knee amputation of the left lower extremity, due to wet gangrene secondary to refractory peripheral artery disease, presents with weakness and dizziness. He says that the symptoms began acutely 24 hours after surgery and have not improved. The amputation was complicated by substantial blood loss. He was placed on empiric antibiotic therapy with ciprofloxacin and clindamycin before the procedure, and blood and wound culture results are still pending. The medical history is significant for type 2 diabetes mellitus and hypertension. Current medications are metformin and lisinopril. The family history is significant for type 2 diabetes mellitus in both parents. Review of symptoms is significant for palpitations and a mild headache for the past 24 hours. His temperature is 38.2°C (100.8°F); blood pressure, 120/70 mm Hg (supine); pulse, 102/min; respiratory rate, 16/min; and oxygen saturation, 99% on room air. When standing, the blood pressure is 90/65 mm Hg and the pulse is 115/min. On physical examination, the patient appears pale and listless. The surgical amputation site does not show any signs of ongoing blood loss or infection. Laboratory tests and an ECG are pending. Which of the following is the next best step in management?
- A. Administer IV fluids
- B. Administer oral fludrocortisone
- C. Administer IV norepinephrine
- D. Administer oral midodrine
- E. Administer IV fluids and withhold lisinopril (Correct Answer)
Pre-operative cardiac risk assessment Explanation: ***Administer IV fluids and withhold lisinopril***
- The patient's **postural orthostatic hypotension** (blood pressure drop upon standing) and symptoms (weakness, dizziness, palpitations, pallor) following significant blood loss during surgery strongly suggest **hypovolemia**, which should be managed immediately with IV fluids.
- **Lisinopril**, an ACE inhibitor, can exacerbate hypotension by blocking angiotensin II-mediated vasoconstriction and aldosterone secretion, so withholding it is crucial in this hypotensive patient.
*Administer IV fluids*
- While administration of IV fluids is a correct component of management for hypovolemia, it is incomplete without addressing potential medication-induced hypotension in this patient.
- Simply administering IV fluids without withholding **lisinopril** may lead to suboptimal correction of the patient's hypotension.
*Administer oral fludrocortisone*
- **Fludrocortisone** is a mineralocorticoid used primarily for chronic orthostatic hypotension, such as in autonomic dysfunction, and would not be appropriate for acute, likely hypovolemia-induced hypotension in a postoperative setting.
- Its effects are not immediate, and it does not address the acute fluid deficit or the potential exacerbating effect of **lisinopril**.
*Administer IV norepinephrine*
- **Norepinephrine** is a potent vasopressor used in distributive or cardiogenic shock, which is not indicated as the initial management for suspected hypovolemia.
- Administering vasopressors in an unresuscitated hypovolemic patient can be dangerous, as it can worsen tissue perfusion by increasing systemic vascular resistance without adequate intravascular volume.
*Administer oral midodrine*
- **Midodrine** is an alpha-1 adrenergic agonist used for chronic orthostatic hypotension to increase peripheral vascular tone, similar to fludrocortisone.
- It works slowly and is not indicated for the acute management of hypovolemic shock or postoperative hypotension.
Pre-operative cardiac risk assessment US Medical PG Question 2: A patient presents with periods of severe headaches and flushing however every time they have come to the physician they have not experienced any symptoms. The only abnormal finding is a blood pressure of 175 mmHg/100 mmHg. It is determined that the optimal treatment for this patient is surgical. Prior to surgery which of the following noncompetitive inhibitors should be administered?
- A. Phentolamine
- B. Isoproterenol
- C. Atropine
- D. Propranolol
- E. Phenoxybenzamine (Correct Answer)
Pre-operative cardiac risk assessment Explanation: ***Phenoxybenzamine***
- This patient likely has a **pheochromocytoma**, which explains the episodic headaches, flushing, and hypertension. **Phenoxybenzamine** is a **non-competitive, irreversible alpha-adrenergic blocker** that is crucial for preoperative preparation to prevent a **hypertensive crisis** during surgery.
- Its **irreversible binding** provides sustained alpha blockade, essential to control blood pressure and avoid catecholamine-induced surges during tumor manipulation.
*Phentolamine*
- **Phentolamine** is a **competitive alpha-adrenergic blocker** used to manage acute hypertensive episodes, but it has a shorter duration of action.
- It is not preferred for sustained preoperative alpha blockade due to its **reversible nature** and potential for drug washout during surgery, which could lead to catecholamine surges.
*Isoproterenol*
- **Isoproterenol** is a **beta-adrenergic agonist** that increases heart rate and contractility, and causes bronchodilation.
- It would be contraindicated in a patient with pheochromocytoma as it could worsen hypertension and cardiac symptoms by stimulating beta receptors that are already overly sensitive to endogenous catecholamines.
*Atropine*
- **Atropine** is a **muscarinic acetylcholine receptor antagonist** that blocks parasympathetic effects, like bradycardia and salivation.
- It has no role in managing hypertension or the catecholamine excess seen in pheochromocytoma.
*Propranolol*
- **Propranolol** is a **non-selective beta-adrenergic blocker** that can be used to control tachycardia and arrhythmias in pheochromocytoma, but only *after* adequate alpha-blockade has been established.
- Using **propranolol alone** or before alpha-blockade can lead to **unopposed alpha-adrenergic stimulation**, resulting in a severe, life-threatening hypertensive crisis.
Pre-operative cardiac risk assessment US Medical PG Question 3: A 64-year-old man presents to his physician for a scheduled follow-up visit. He has chronic left-sided heart failure with systolic dysfunction. His current regular medications include captopril and digoxin, which were started after his last episode of symptomatic heart failure approximately 3 months ago. His last episode of heart failure was accompanied by atrial fibrillation, which followed an alcohol binge over a weekend. Since then he stopped drinking. He reports that he has no current symptoms at rest and is able to perform regular physical exercise without limitation. On physical examination, mild bipedal edema is noted. The physician suggested to him that he should discontinue digoxin and continue captopril and scheduled him for the next follow-up visit. Which of the following statements best justifies the suggestion made by the physician?
- A. Long-term digoxin therapy produces significant survival benefits in patients with heart failure, but at the cost of increased heart failure-related admissions.
- B. Both captopril and digoxin are likely to improve the long-term survival of the patient with heart failure, but digoxin has more severe side effects.
- C. Captopril is likely to improve the long-term survival of the patient with heart failure, unlike digoxin.
- D. Digoxin does not benefit patients with left-sided heart failure in the absence of atrial fibrillation.
- E. Digoxin is useful to treat atrial fibrillation, but does not benefit patients with systolic dysfunction who are in sinus rhythm. (Correct Answer)
Pre-operative cardiac risk assessment Explanation: ***Digoxin is useful to treat atrial fibrillation, but does not benefit patients with systolic dysfunction who are in sinus rhythm.***
- The patient's **atrial fibrillation** was likely triggered by the alcohol binge and has since resolved, suggesting he is now in **sinus rhythm**.
- Digoxin's primary benefit in heart failure with **systolic dysfunction** (HFrEF) is to control ventricular rate in patients with **atrial fibrillation**, but it does not offer survival benefit in HFrEF patients who are in **sinus rhythm** and well-managed with other therapies.
*Long-term digoxin therapy produces significant survival benefits in patients with heart failure, but at the cost of increased heart failure-related admissions.*
- This statement is incorrect; digoxin has been shown to **reduce hospital admissions** for heart failure, but it does **not provide a significant survival benefit** in patients with HFrEF in sinus rhythm.
- The main benefit of digoxin in HFrEF is to improve symptoms and quality of life, alongside reducing hospitalizations, but not prolonging life.
*Both captopril and digoxin are likely to improve the long-term survival of the patient with heart failure, but digoxin has more severe side effects.*
- **Captopril (an ACE inhibitor)** does improve **long-term survival** in heart failure, but **digoxin does not** demonstrably improve survival.
- While digoxin can have side effects, its lack of survival benefit for HFrEF in sinus rhythm is the primary reason for discontinuation, not just side effect severity.
*Captopril is likely to improve the long-term survival of the patient with heart failure, unlike digoxin.*
- This statement is partially correct that **captopril improves survival**, but it does not fully explain the physician's decision to discontinue digoxin.
- The key missing piece is the patient's current **sinus rhythm** and the lack of benefit of digoxin in that specific context for HFrEF.
*Digoxin does not benefit patients with left-sided heart failure in the absence of atrial fibrillation.*
- This statement is nearly correct, but "left-sided heart failure" is broad. It is specifically in patients with **systolic dysfunction (HFrEF)** who are in **sinus rhythm** that digoxin lacks significant benefit beyond symptom control, and does not provide survival benefit.
Pre-operative cardiac risk assessment US Medical PG Question 4: A 62-year-old man comes to the physician in May for a routine health maintenance examination. He feels well. He underwent a right inguinal hernia repair 6 months ago. He has hypertension and type 2 diabetes mellitus. There is no family history of serious illness. Current medications include metformin, sitagliptin, enalapril, and metoprolol. He received the zoster vaccine 1 year ago. He received the PPSV23 vaccine 4 years ago. His last colonoscopy was 7 years ago and was normal. He smoked a pack of cigarettes a day for 20 years but quit 17 years ago. He drinks two to three alcoholic beverages on weekends. He is allergic to amoxicillin. He is scheduled to visit Australia and New Zealand in 2 weeks to celebrate his 25th wedding anniversary. He appears healthy. Vital signs are within normal limits. An S4 is heard at the apex. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate recommendation at this time?
- A. Colonoscopy
- B. Influenza vaccine (Correct Answer)
- C. Pneumococcal conjugate vaccine 13
- D. Cardiac stress test
- E. Abdominal ultrasound
Pre-operative cardiac risk assessment Explanation: ***Influenza vaccine***
- Current guidelines recommend annual **influenza vaccination** for all adults, particularly those over 60 years old and those with chronic medical conditions like diabetes and hypertension.
- **Critical timing consideration**: The patient is traveling to Australia and New Zealand (Southern Hemisphere) in 2 weeks, where it will be **winter season** (May-September) with peak influenza activity.
- He is a **high-risk patient** (age >60, diabetes, hypertension, cardiovascular disease) who should receive influenza vaccine before travel to areas experiencing influenza season.
- This is the **most appropriate and time-sensitive recommendation** at this visit.
*Colonoscopy*
- The patient had a normal colonoscopy 7 years ago; current guidelines suggest a repeat colonoscopy every **10 years** for average-risk individuals.
- There are no new symptoms, family history, or risk factors that would necessitate an earlier repeat colonoscopy at this time.
*Pneumococcal conjugate vaccine 13*
- The patient received **PPSV23** four years ago at approximately age 58.
- Per **current CDC guidelines (2019+)**, PCV13 is **no longer routinely recommended** for immunocompetent adults ≥65 years old.
- PPSV23 alone is now the standard recommendation for adults ≥65, which this patient has already received.
- PCV13 may be considered through **shared decision-making** in specific circumstances, but is not a routine or urgent recommendation.
*Cardiac stress test*
- Although the patient has risk factors for cardiovascular disease (hypertension, diabetes, former smoker) and an **S4 heart sound** (indicating **left ventricular hypertrophy**), he is asymptomatic.
- Routine **screening stress tests** are not recommended for asymptomatic individuals without signs of active cardiac ischemia.
*Abdominal ultrasound*
- There are **no symptoms** or specific indications (e.g., abdominal aortic aneurysm screening criteria not met - would need age 65-75 with smoking history).
- The patient is 62 years old and quit smoking 17 years ago, so AAA screening criteria are not yet met.
- Routine screening abdominal ultrasounds are not indicated.
Pre-operative cardiac risk assessment US Medical PG Question 5: A 50-year-old woman comes to the physician for a routine health maintenance examination. She has no personal or family history of serious illness. She smoked one pack of cigarettes daily for 5 years during her 20s. Her pulse is 70/min, and blood pressure is 120/78 mm Hg. Serum lipid studies and glucose concentration are within the reference ranges. Which of the following health maintenance recommendations is most appropriate at this time?
- A. Perform BRCA gene test
- B. Perform abdominal ultrasound
- C. Perform 24-hour ECG
- D. Perform DEXA scan
- E. Perform colonoscopy (Correct Answer)
Pre-operative cardiac risk assessment Explanation: ***Perform colonoscopy***
- **Colorectal cancer screening** with colonoscopy is generally recommended for individuals at average risk starting at age **45-50 years**.
- This patient is **50 years old** and has no increased risk factors, making routine colonoscopy the most appropriate screening.
*Perform BRCA gene test*
- **BRCA gene testing** is indicated for individuals with a strong **family history** of breast or ovarian cancer, or those with personal history suggesting a genetic predisposition.
- This patient has **no personal or family history** of serious illness, so BRCA testing is not warranted.
*Perform abdominal ultrasound*
- **Abdominal ultrasound** is typically used to investigate specific symptoms or screen for conditions like **abdominal aortic aneurysm** in high-risk individuals (e.g., male smokers over 65).
- This patient has **no relevant symptoms** or risk factors for which routine abdominal ultrasound screening is recommended.
*Perform 24-hour ECG*
- A **24-hour ECG (Holter monitor)** is used to detect paroxysmal **arrhythmias** or evaluate symptoms like palpitations, syncope, or dizziness.
- This patient is asymptomatic with a normal pulse and blood pressure; therefore, **routine 24-hour ECG** is not indicated.
*Perform DEXA scan*
- A **DEXA scan** is recommended for **osteoporosis screening** in women typically starting at age **65**, or earlier if they have significant risk factors like a history of fragility fractures or certain medical conditions.
- At **50 years old** and with no apparent risk factors for osteoporosis, a DEXA scan is not yet routinely indicated according to general guidelines.
Pre-operative cardiac risk assessment US Medical PG Question 6: An 83-year-old male presents with dyspnea, orthopnea, and a chest radiograph demonstrating pulmonary edema. A diagnosis of congestive heart failure is considered. The following clinical measurements are obtained: 100 bpm heart rate, 0.2 mL O2/mL systemic blood arterial oxygen content, 0.1 mL O2/mL pulmonary arterial oxygen content, and 400 mL O2/min oxygen consumption. Using the above information, which of the following values represents this patient's cardiac stroke volume?
- A. 30 mL/beat
- B. 70 mL/beat
- C. 40 mL/beat (Correct Answer)
- D. 60 mL/beat
- E. 50 mL/beat
Pre-operative cardiac risk assessment Explanation: ***40 mL/beat***
- First, calculate cardiac output (CO) using the **Fick principle**: CO = Oxygen Consumption / (Arterial O2 content - Venous O2 content). Here, CO = 400 mL O2/min / (0.2 mL O2/mL - 0.1 mL O2/mL) = 400 mL O2/min / 0.1 mL O2/mL = **4000 mL/min**.
- Next, calculate stroke volume (SV) using the formula: SV = CO / Heart Rate. Given a heart rate of 100 bpm, SV = 4000 mL/min / 100 beats/min = **40 mL/beat**.
*30 mL/beat*
- This answer would result if there was an error in calculating either the **cardiac output** or if the **arteriovenous oxygen difference** was overestimated.
- A stroke volume of 30 mL/beat with a heart rate of 100 bpm would yield a cardiac output of 3 L/min, which is sub-physiologic for an oxygen consumption of 400 mL/min given the provided oxygen content values.
*70 mL/beat*
- This stroke volume is higher than calculated and would imply either a significantly **lower heart rate** or a much **higher cardiac output** than derived from the Fick principle with the given values.
- A stroke volume of 70 mL/beat at a heart rate of 100 bpm would mean a cardiac output of 7 L/min, which is inconsistent with the provided oxygen consumption and arteriovenous oxygen difference.
*60 mL/beat*
- This value is higher than the correct calculation, suggesting an error in the initial calculation of **cardiac output** or the **avO2 difference**.
- To get 60 mL/beat, the cardiac output would need to be 6000 mL/min, which would mean an avO2 difference of 0.067 mL O2/mL, not 0.1 mL O2/mL.
*50 mL/beat*
- This stroke volume would result from an incorrect calculation of the **cardiac output**, potentially from a slight miscalculation of the **arteriovenous oxygen difference**.
- A stroke volume of 50 mL/beat at 100 bpm would mean a cardiac output of 5 L/min, requiring an avO2 difference of 0.08 mL O2/mL, which is not consistent with the given values.
Pre-operative cardiac risk assessment US Medical PG Question 7: A 41-year-old man presents to his primary care provider because of chest pain with activity for the past 6 months. Past medical history is significant for appendectomy at age 12 and hypertension, and diabetes mellitus type 2 that is poorly controlled. He takes metformin and lisinopril but admits that he is bad at remembering to take them everyday. His father had a heart attack at 41 and 2 stents were placed in his heart. His mother is healthy. He drinks alcohol occasionally and smokes a half of a pack of cigarettes a day. He is a sales executive and describes his work as stressful. Today, the blood pressure is 142/85 and the body mass index (BMI) is 28.5 kg/m2. A coronary angiogram shows > 75% narrowing of the left anterior descending coronary artery. Which of the following is most significant in this patient?
- A. Obesity
- B. Family history
- C. Hypertension
- D. Smoking
- E. Diabetes mellitus (Correct Answer)
Pre-operative cardiac risk assessment Explanation: ***Diabetes mellitus***
- **Diabetes mellitus** is a significant risk factor for **atherosclerosis** and contributes to accelerated progression of **coronary artery disease (CAD)**, often leading to more widespread and severe disease.
- Poorly controlled diabetes can cause **endothelial dysfunction**, increasing oxidative stress and inflammation, which are key processes in **plaque formation** and destabilization.
*Obesity*
- **Obesity** (BMI 28.5 kg/m2) is a risk factor for **CAD** but often acts through associated conditions like **hypertension**, **diabetes**, and **dyslipidemia**.
- While it contributes to overall cardiovascular risk, it is less directly pathogenic than diabetes which independently accelerates **atherosclerosis**.
*Family history*
- The patient's father had a **heart attack at 41**, which is a significant risk factor for **early-onset CAD**.
- However, the patient has multiple modifiable risk factors (smoking, hypertension, diabetes) that are independently and more directly contributing to his current presentation.
*Hypertension*
- **Hypertension** (142/85 mmHg) is a major modifiable risk factor that causes **endothelial damage** and promotes **atherosclerosis**.
- While important, the patient's **poorly controlled diabetes mellitus** often creates a more aggressive environment for plaque formation and progression compared to hypertension alone.
*Smoking*
- **Smoking** is a potent, modifiable risk factor that causes direct vascular injury, promotes **thrombogenesis**, and contributes to **atherosclerosis**.
- Although highly detrimental, smoking is one of several significant risk factors; **diabetes mellitus**, with its systemic metabolic impact, can be considered more broadly influential in the severity and diffuse nature of **CAD**.
Pre-operative cardiac risk assessment US Medical PG Question 8: A 66-year-old female with hypertension and a recent history of acute ST-elevation myocardial infarction (STEMI) 6 days previous, treated with percutaneous transluminal angioplasty (PTA), presents with sudden onset chest pain, shortness of breath, diaphoresis, and syncope. Vitals are temperature 37°C (98.6°F), blood pressure 80/50 mm Hg, pulse 125/min, respirations 12/min, and oxygen saturation 92% on room air. On physical examination, the patient is pale and unresponsive. Cardiac exam reveals tachycardia and a pronounced holosystolic murmur loudest at the apex and radiates to the back. Lungs are clear to auscultation. Chest X-ray shows cardiomegaly with clear lung fields. ECG is significant for ST elevations in the precordial leads (V2-V4) and low-voltage QRS complexes. Emergency transthoracic echocardiography shows a left ventricular wall motion abnormality along with a significant pericardial effusion. The patient is intubated, and aggressive fluid resuscitation is initiated. What is the next best step in management?
- A. Immediate cardiac catheterization
- B. Immediate transfer to the operating room (Correct Answer)
- C. Emergency pericardiocentesis
- D. Intra-aortic balloon counterpulsation
- E. Administer dobutamine 5-10 mcg/kg/min IV
Pre-operative cardiac risk assessment Explanation: ***Immediate transfer to the operating room***
- The patient's presentation with sudden onset chest pain, shortness of breath, profound cardiogenic shock, and a new **holosystolic murmur at the apex radiating to the back** in the context of a recent **STEMI**, strongly suggests **acute papillary muscle rupture** causing severe mitral regurgitation. This is a surgical emergency requiring immediate intervention.
- The holosystolic murmur at the apex is pathognomonic for acute mitral regurgitation, distinguishing this from ventricular free wall rupture (which would present with tamponade physiology without a murmur).
- The patient requires urgent surgical repair (mitral valve replacement or repair) to address this mechanical complication of **myocardial infarction (MI)**, which is causing severe hemodynamic compromise.
*Immediate cardiac catheterization*
- While cardiac catheterization is essential for diagnosing coronary artery disease and revascularization, in this emergent situation with profound shock and a mechanical complication (papillary muscle rupture), the primary issue is structural cardiac damage requiring surgical repair, not ongoing ischemia alone.
- Delaying surgical intervention for catheterization in this hemodynamically unstable patient would be detrimental and potentially fatal.
*Emergency pericardiocentesis*
- Although there is a **pericardial effusion** on echocardiography, the patient's presentation with a new holosystolic murmur and profound shock after STEMI indicates **papillary muscle rupture with acute mitral regurgitation**, not cardiac tamponade.
- The presence of a loud murmur excludes ventricular free wall rupture as the primary cause. The effusion is likely reactive or incidental.
- Pericardiocentesis would not address the underlying mitral valve pathology causing the hemodynamic collapse.
*Intra-aortic balloon counterpulsation*
- **Intra-aortic balloon pump (IABP)** can improve cardiac output and reduce afterload, which may provide temporary hemodynamic support in cardiogenic shock.
- However, in cases of **papillary muscle rupture** with severe acute mitral regurgitation, IABP provides only temporary support and does not fix the underlying structural problem.
- It could be considered as a bridge to surgery, but the definitive treatment is surgical repair, which should be expedited without delay.
*Administer dobutamine 5-10 mcg/kg/min IV*
- **Dobutamine** is an inotrope that increases cardiac contractility. While it might improve cardiac output in some forms of cardiogenic shock, in the setting of **acute severe mitral regurgitation from papillary muscle rupture**, it cannot resolve the structural valvular incompetence.
- Increasing contractility may paradoxically worsen the regurgitant fraction and further compromise forward cardiac output.
- Medical management alone cannot resolve this mechanical complication, necessitating urgent surgical intervention.
Pre-operative cardiac risk assessment US Medical PG Question 9: A 39-year-old woman comes to the physician because of a 5-month history of episodic retrosternal chest pain. She currently feels well. The pain is unrelated to exercise and does not radiate. The episodes typically last less than 15 minutes and lead to feelings of anxiety; resting relieves the pain. She has not had dyspnea or cough. She has hyperlipidemia treated with simvastatin. She does not smoke, drink alcohol, or use illicit drugs. Her temperature is 37°C (98.6°F), pulse is 104/min, respirations are 17/min, and blood pressure is 124/76 mm Hg. Cardiopulmonary examination shows no abnormalities. An ECG shows sinus tachycardia. Which of the following is the most appropriate next step in the evaluation of coronary artery disease in this patient?
- A. Nuclear exercise stress test
- B. No further testing needed
- C. Troponin I measurement
- D. Dobutamine stress echocardiography
- E. Coronary CT angiogram (Correct Answer)
Pre-operative cardiac risk assessment Explanation: ***Coronary CT angiogram***
- This patient has symptoms (non-exertional chest pain) raising suspicion for coronary artery disease (CAD), but her pre-test probability is low due to young age, female gender, and non-anginal features, making **coronary CT angiogram** an appropriate non-invasive first-line test.
- CT angiogram offers high sensitivity for detecting **coronary atherosclerosis** and can rule out CAD in patients with low-to-intermediate pretest probability.
*Nuclear exercise stress test*
- This test is typically reserved for patients with a **higher pre-test probability of CAD** or those with equivocal initial findings, as it involves radiation exposure and is more resource-intensive.
- The patient's chest pain is **unrelated to exercise**, making an exercise-based stress test less directly relevant as a first-line diagnostic.
*No further testing needed*
- While the patient's symptoms are atypical, her risk factor (hyperlipidemia) and recurrent retrosternal pain warrant further evaluation to **rule out CAD**, even with a low pre-test probability.
- Dismissing symptoms without further testing could miss early or atypical presentations of CAD.
*Troponin I measurement*
- **Troponin I** is used to diagnose **acute myocardial infarction** and indicates active myocardial necrosis; it is not for evaluating chronic, episodic chest pain in a patient who currently feels well.
- Her current well-being and the episodic nature of her pain make acute cardiac injury unlikely, and a normal troponin would not rule out underlying CAD.
*Dobutamine stress echocardiography*
- **Dobutamine stress echocardiography** is typically used for patients who cannot perform an exercise stress test (e.g., due to mobility issues) or when an exercise ECG is non-diagnostic.
- Given the patient's ability to exert herself (implied by no known mobility issues) and a non-exertional pain pattern, a CT angiogram offers superior anatomical detail for initial investigation.
Pre-operative cardiac risk assessment US Medical PG Question 10: A 69-year-old man is scheduled to undergo radical retropubic prostatectomy for prostate cancer in 2 weeks. He had a myocardial infarction at the age of 54 years. He has a history of GERD, unstable angina, hyperlipidemia, and severe osteoarthritis in the left hip. He is unable to climb up stairs or walk fast because of pain in his left hip. He had smoked one pack of cigarettes daily for 30 years but quit 25 years ago. He drinks one glass of wine daily. Current medications include aspirin, metoprolol, lisinopril, rosuvastatin, omeprazole, and ibuprofen as needed. His temperature is 36.4°C (97.5°F), pulse is 90/min, and blood pressure is 136/88 mm Hg. Physical examination shows no abnormalities. A 12-lead ECG shows Q waves and inverted T waves in leads II, III, and aVF. His B-type natriuretic protein is 84 pg/mL (N < 125). Which of the following is the most appropriate next step in management to assess this patient's perioperative cardiac risk?
- A. No further testing
- B. 24-hour ambulatory ECG monitoring
- C. Radionuclide myocardial perfusion imaging (Correct Answer)
- D. Treadmill stress test
- E. Resting echocardiography
Pre-operative cardiac risk assessment Explanation: ***Radionuclide myocardial perfusion imaging***
- This patient requires **perioperative cardiac risk assessment** before intermediate-risk surgery (radical prostatectomy).
- Key factors include: history of **myocardial infarction**, current cardiac risk factors, and **inability to exercise** due to severe osteoarthritis.
- Since he cannot perform exercise stress testing, **pharmacologic stress testing** with radionuclide myocardial perfusion imaging (using agents like adenosine, dipyridamole, or regadenoson) is the most appropriate test to assess for **inducible myocardial ischemia**.
- This provides functional assessment of coronary perfusion under pharmacologic stress, helping guide perioperative risk stratification and management.
- *Note: The presence of unstable angina would typically require cardiac stabilization first; this question focuses on selecting the appropriate stress test modality for a patient unable to exercise.*
*No further testing*
- This patient has significant cardiac risk factors including **prior MI**, ongoing cardiac medications, and ECG changes suggesting old infarction.
- Proceeding directly to surgery without functional cardiac assessment would be **inappropriate** given his risk profile and the intermediate-risk nature of the planned surgery.
*24-hour ambulatory ECG monitoring*
- Holter monitoring detects arrhythmias and silent ischemic episodes but does not provide **functional capacity assessment** or evaluation of inducible ischemia under stress conditions.
- It is not the primary tool for **perioperative cardiac risk stratification** before major surgery.
*Treadmill stress test*
- The patient's **severe osteoarthritis** prevents him from climbing stairs or walking fast, making him unable to achieve adequate exercise workload for a treadmill stress test.
- This functional limitation makes **exercise stress testing contraindicated**; pharmacologic stress testing is required instead.
*Resting echocardiography*
- Resting echocardiography assesses **baseline left ventricular function**, wall motion abnormalities from prior infarction, and valvular disease.
- While useful for structural assessment, it does **not evaluate for exercise-induced or stress-induced ischemia**, which is critical for perioperative risk assessment in patients with coronary artery disease.
- His normal BNP (84 pg/mL) suggests adequate baseline ventricular function, making functional ischemia assessment more relevant than structural evaluation alone.
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