Anesthesia for Interventional Cardiology — MCQs
Which anesthetic agent is considered the least cardiotoxic?
MC late complication of central venous line is:
The most sensitive and practical technique for detection of myocardial ischemia in the perioperative period is -
A patient is on follow-up for recurrent abdominal pain. USG reveals an aortic aneurysm of 40 mm. What should be the next immediate step?
During cesarean section under general endotracheal anaesthesia, venous air embolism
A patient after valve replacement will require follow up treatment with
Abbreviated laparotomy done for:
Problems which may result from hypotensive anesthesia include:
Which of the following is not a component of the Goldman Revised Cardiac Risk Index?
Patient shows ST depression, troponin rise 6h post-surgery. Next best step is:
Anesthesia for Interventional Cardiology Indian Medical PG Practice Questions and MCQs
Question 1: Which anesthetic agent is considered the least cardiotoxic?
- A. Isoflurane
- B. Enflurane
- C. Sevoflurane (Correct Answer)
- D. Halothane
Explanation: ***Sevoflurane*** - Sevoflurane is known for its **smooth induction** and rapid recovery, making it a common choice, especially in pediatric anesthesia [3]. - It has a relatively **low pungency** and minimal cardiovascular depressant effects compared to other volatile anesthetics, contributing to its favorable cardiotoxicity profile [1], [4]. *Enflurane* - Enflurane can cause **myocardial depression** and may induce **seizures** at higher concentrations, limiting its use [1]. - Its widespread use has decreased due to concerns about its **cardiovascular effects** and potential for **renal toxicity**. *Isoflurane* - While Isoflurane is a commonly used anesthetic, it can cause **coronary steal phenomenon** in patients with coronary artery disease due to its potent vasodilatory effects. - It also causes dose-dependent **myocardial depression** and can increase heart rate, which may be detrimental in some patients [4]. *Halothane* - Halothane is known for significant **myocardial depression**, causing a decrease in cardiac output and systemic vascular resistance [2]. - It also sensitizes the myocardium to **catecholamines**, increasing the risk of arrhythmias, and is associated with **halothane hepatitis**, a rare but severe liver injury [3].
Question 2: MC late complication of central venous line is:
- A. Sepsis (Correct Answer)
- B. Thromboembolism
- C. Cardiac arrhythmias
- D. Air embolism
Explanation: **Sepsis** - **Catheter-related bloodstream infections (CRBSIs)** are the most common late complication of central venous lines, leading to sepsis [1]. - The risk of sepsis increases with the **duration** of catheter placement, frequency of line access, and inadequate aseptic technique [1]. *Air embolism* - An **air embolism** is typically an immediate or early complication during insertion or removal of the central line, or connection/disconnection of administration sets. - It is not considered a late complication as it occurs due to a sudden entry of air into the venous system. *Thromboembolism* - While **thrombosis** can complicate central venous lines, leading to potential thromboembolism, it is less common than sepsis as a late complication [2]. - The formation of a thrombus is often localized to the catheter tip or vessel wall and may or may not lead to a symptomatic embolism [2]. *Cardiac arrhythmias* - **Cardiac arrhythmias** can occur during central venous line insertion if the guidewire or catheter tip irritates the myocardium, making it an immediate or early complication. - This is usually a transient event and not a long-term or late complication associated with the mere presence of the catheter.
Question 3: The most sensitive and practical technique for detection of myocardial ischemia in the perioperative period is -
- A. Direct measurement of end diastolic pressure
- B. Radio labeled lactate determination
- C. Magnetic Resonance Spectroscopy
- D. Regional wall motion abnormality detected with the help of 2D transoesophageal echocardiography (Correct Answer)
Explanation: ***Regional wall motion abnormality detected with the help of 2D transesophageal echocardiography*** - **Transesophageal echocardiography (TEE)** provides high-resolution images of the heart, allowing for the sensitive detection of **regional wall motion abnormalities (RWMA)**, an early and practical indicator of myocardial ischemia in the perioperative setting. - The development of new or worsening RWMA is often the **first sign of ischemia**, preceding ECG changes or hemodynamic alterations, making it a highly sensitive and clinically useful tool. *Direct measurement of end-diastolic pressure* - While an elevated **end-diastolic pressure** can indicate ventricular dysfunction, it is an **indirect sign** and not specific enough for early myocardial ischemia detection. - This measurement often requires invasive monitoring, which is less practical for routine detection compared to TEE. *Radio-labeled lactate determination* - **Lactate production** can increase in ischemic tissue, but its detection is a **biochemical marker** that typically lags behind the onset of ischemia. - This technique is generally **research-oriented** and not a practical, bedside method for rapid perioperative ischemia detection. *Magnetic Resonance Spectroscopy* - **Magnetic Resonance Spectroscopy (MRS)** can provide detailed metabolic information about tissue, including changes related to ischemia. - However, it is a **complex, time-consuming, and expensive imaging modality** that is not practical for routine, real-time perioperative monitoring of myocardial ischemia.
Question 4: A patient is on follow-up for recurrent abdominal pain. USG reveals an aortic aneurysm of 40 mm. What should be the next immediate step?
- A. Establish surveillance protocol with repeat imaging in 6-12 months. (Correct Answer)
- B. Initiate medical management with beta-blockers.
- C. Perform surgical intervention immediately.
- D. Start antihypertensive therapy immediately.
Explanation: ***Establish surveillance protocol with repeat imaging in 6-12 months.*** - A **40mm abdominal aortic aneurysm (AAA)** is below the threshold for elective surgical repair (typically **55mm for men, 50mm for women**). - The **immediate next step** is to establish a **surveillance protocol** with repeat imaging at appropriate intervals (every **6-12 months** for 40-44mm AAAs). - Surveillance allows monitoring of aneurysm growth rate and timely intervention if it expands to surgical threshold or becomes symptomatic. - **Risk factor modification** (smoking cessation, BP control, statin therapy) should accompany surveillance but is secondary to establishing the monitoring plan. *Initiate medical management with beta-blockers.* - **Beta-blockers are NOT recommended** for AAA management and may actually be harmful by reducing aortic wall stress detection. - Current guidelines do not support routine pharmacological therapy specifically to prevent AAA expansion, though **statins** may have some benefit. *Perform surgical intervention immediately.* - A **40mm AAA is well below surgical threshold** and does not require immediate intervention. - Surgery is considered when AAA reaches **≥55mm (men) or ≥50mm (women)**, growth rate **>10mm/year**, or when **symptomatic/ruptured**. *Start antihypertensive therapy immediately.* - While **blood pressure control is important** in AAA management, it is not the immediate next step without first establishing a surveillance protocol. - Antihypertensive therapy should be part of overall cardiovascular risk management but assumes the patient is hypertensive (not specified in the question).
Question 5: During cesarean section under general endotracheal anaesthesia, venous air embolism
- A. Induces severe hypertension
- B. Is associated with decreased end-tidal CO2 (Correct Answer)
- C. Should be treated with nitrous oxide
- D. Is associated with high end-tidal CO2
Explanation: ***Is associated with decreased end-tidal CO2*** - Venous air embolism causes **pulmonary artery obstruction**, leading to ventilation-perfusion mismatch and decreased blood flow to the lungs. - This reduced pulmonary blood flow results in a significant **decrease in expired CO2**, as less CO2 is delivered to the alveoli for exhalation. *Induces severe hypertension* - Venous air embolism typically causes **hypotension** due to reduced cardiac output and right ventricular failure, not hypertension. - Direct effects of air in the circulation include **vasodilation** and myocardial depression, contributing to a drop in blood pressure. *Should be treated with nitrous oxide* - **Nitrous oxide** should be avoided in cases of venous air embolism as it expands gas-filled spaces, potentially increasing the size of the air embolus and worsening patient outcomes. - Treatment involves 100% oxygen, Trendelenburg position, left lateral decubitus, and aspiration of air from the right atrium, not the administration of additional gas. *Is associated with high end-tidal CO2* - A high end-tidal CO2 would indicate improved ventilation or perfusion, which is contrary to the effects of a venous air embolism that **reduces pulmonary blood flow** and thus CO2 exchange. - The hallmark respiratory sign of venous air embolism is a **sudden profound decrease in end-tidal CO2** due to arterial obstruction.
Question 6: A patient after valve replacement will require follow up treatment with
- A. ACE inhibitors
- B. Beta blockers
- C. Thiazide
- D. Warfarin (Correct Answer)
Explanation: ***Warfarin*** - Patients with **mechanical prosthetic heart valves** require lifelong anticoagulation with **warfarin** to prevent life-threatening thromboembolic complications [1]. - The target **international normalized ratio (INR)** typically ranges from 2.5 to 3.5, depending on the valve type and position. *ACE inhibitors* - **ACE inhibitors** are primarily used for managing **hypertension**, **heart failure**, and **renal protection**, not as routine post-valve replacement prophylaxis [2]. - While they may be used if these co-morbidities exist, they are not a universal requirement after valve surgery. *Beta blockers* - **Beta blockers** are often prescribed to control heart rate, manage **hypertension**, or reduce myocardial oxygen demand, but they are not the primary follow-up treatment for all valve replacement patients. - They do not address the critical need for **anticoagulation** in mechanical valve recipients. *Thiazide* - **Thiazide diuretics** are used to treat **hypertension** and **edema** by increasing salt and water excretion. - They do not play a direct role in preventing **thromboembolism** post-valve replacement and are not generally indicated unless chronic heart failure or hypertension is present.
Question 7: Abbreviated laparotomy done for:
- A. Hemodynamically stable patients with minor trauma
- B. Damage control in hemodynamically unstable trauma patients (Correct Answer)
- C. Elective abdominal surgeries
- D. Early wound healing promotion
Explanation: ***Damage control in hemodynamically unstable trauma patients*** - **Abbreviated laparotomy** is a key component of **damage control surgery**, primarily indicated for hemodynamically unstable trauma patients. - The goal is to rapidly control life-threatening issues like hemorrhage and contamination, then temporarily close the abdomen for physiologic stabilization before definitive repair. *Hemodynamically stable patients with minor trauma* - These patients typically do not require prompt surgical intervention; their injuries can often be managed non-operatively or with standard surgical techniques. - An abbreviated laparotomy is an aggressive approach reserved for severe, life-threatening scenarios, not minor trauma in stable patients. *Elective abdominal surgeries* - Elective surgeries are planned procedures performed on stable patients with no immediate life-threatening conditions. - They allow for complete surgical repair in a single setting, which is the opposite of the staged approach of an abbreviated laparotomy. *Early wound healing promotion* - The focus of an abbreviated laparotomy is on resuscitation and source control, not primarily on wound healing. - The initial closure is temporary, often leaving the wound open, which is not conducive to early, primary wound healing.
Question 8: Problems which may result from hypotensive anesthesia include:
- A. Deep vein thrombosis
- B. Reactionary hemorrhage
- C. Retraction anemia
- D. All of the options (Correct Answer)
Explanation: ***All of the options*** - Hypotensive anesthesia is a technique used to reduce **blood pressure** during surgery, aiming to decrease **blood loss** and improve the **surgical field visibility**. - While beneficial, it carries inherent risks including **deep vein thrombosis (DVT), reactionary hemorrhage**, and complications like **retraction anemia** if not managed properly. *Deep vein thrombosis (DVT)* - While hypotension might seem to reduce the risk by lowering **blood flow velocity**, prolonged immobility and potential for **venous stasis** during any surgery, especially under hypotension, can increase DVT risk. - The combination of **endothelial dysfunction** and **hypercoagulability** often seen in surgical patients, coupled with reduced peripheral blood flow due to hypotension, can contribute to DVT formation. *Reactionary hemorrhage* - This is a common post-operative complication where bleeding restarts hours after surgery. With hypotensive anesthesia, **blood vessels** are constricted and may not be actively bleeding during the surgery. - As the patient's **blood pressure** returns to normal post-operatively, these previously undetected bleeds can manifest as significant **hemorrhage** due to the increased pressure. *Retraction anemia* - This term is less commonly used in medical literature. However, it likely refers to the complications arising from prolonged tissue retraction during surgery, which, when combined with reduced **perfusion** from hypotensive anesthesia, can lead to **tissue ischemia** or damage akin to anemia in the affected area. - The reduced **oxygen delivery** to tissues during hypotensive states, especially when further compromised by retraction, may result in localized tissue injury or contribute to systemic complications if severe or prolonged.
Question 9: Which of the following is not a component of the Goldman Revised Cardiac Risk Index?
- A. History of preoperative treatment with insulin
- B. History of preoperative serum creatinine >2.0 mg/dL
- C. Age > 80 yrs (Correct Answer)
- D. History of ischemic heart disease
Explanation: ***Age > 80 yrs*** - **Age** is not a parameter included in the Goldman Revised Cardiac Risk Index for predicting postoperative cardiac complications. - The index focuses on specific medical conditions and surgical risk factors. *History of preoperative treatment with insulin* - This is a component of the **Goldman Revised Cardiac Risk Index**, indicating **insulin-dependent diabetes mellitus**. - Diabetes requiring insulin treatment is a significant risk factor for cardiac complications during surgery. *History of preoperative serum creatinine >2.0 mg/dL* - An elevated **serum creatinine** (>2.0 mg/dL) is a recognized component of the index, reflecting **renal insufficiency**. - **Renal impairment** is associated with increased cardiac risk in the perioperative period. *History of ischemic heart disease* - This is a key component of the Goldman Revised Cardiac Risk Index, as a history of **ischemic heart disease** (e.g., prior myocardial infarction, angina) significantly increases perioperative cardiac risk. - Patients with existing heart disease are more susceptible to cardiac events during and after surgery.
Question 10: Patient shows ST depression, troponin rise 6h post-surgery. Next best step is:
- A. 12-lead ECG
- B. Echocardiogram
- C. Cardiology consult (Correct Answer)
- D. Start heparin
Explanation: ***Cardiology consult*** - A cardiology consult is the most appropriate next step given the presence of **ST depression** and a **troponin rise** post-surgery, indicating a likely myocardial infarction (MI). - This allows for prompt comprehensive evaluation, risk stratification, and initiation of specialized cardiac management by an expert. *12-lead ECG* - While a 12-lead ECG is an important diagnostic tool, the patient's existing **ST depression** suggests it has already been performed or noted. - A repeat ECG might be useful for tracking changes, but it doesn't replace the need for expert cardiac evaluation and management. *Echocardiogram* - An echocardiogram can assess **cardiac function**, wall motion abnormalities, and valvular issues, which are relevant in MI. - However, it's a diagnostic test that should be ordered and interpreted in the context of a broader cardiac workup, which a cardiologist can best coordinate. *Start heparin* - **Heparin** is an anticoagulant that may be part of the management for an MI, especially in certain types or for prevention of clot extension. - However, initiating anticoagulation should be done after a thorough assessment of the patient's cardiac status, bleeding risk post-surgery, and in consultation with cardiology, rather than as the immediate next best step.
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