Pacemakers and ICDs US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Pacemakers and ICDs. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Pacemakers and ICDs US Medical PG Question 1: A 16-year-old male presents to the cardiologist after passing out during a basketball practice. An echocardiogram confirmed the diagnosis of hypertrophic cardiomyopathy. The cardiologist advises that a pacemaker must be implanted to prevent any further complications and states the player cannot play basketball anymore. Unfortunately, the coach objects to sidelining the player since a big game against their rivals is next week. The coach asks if the pacemaker can be implanted after the game, which of the following steps should the physician take?
- A. Postpone the procedure so the patient can play
- B. Allow the patient to play and schedule a follow up after the game
- C. Recommend to the legal guardian that the player stop playing and have the procedure performed (Correct Answer)
- D. Perform the procedure immediately so that both the physician and coach's wishes may be fulfilled
- E. Allow the patient to make the decision regarding his health
Pacemakers and ICDs Explanation: ***Recommend to the legal guardian that the player stop playing and have the procedure performed***
- The physician's primary ethical duty is **beneficence** and **non-maleficence**, meaning acting in the patient's best interest and preventing harm.
- Playing basketball with **hypertrophic cardiomyopathy** carries a significant risk of sudden cardiac death, making it medically unsafe regardless of the coach's objections.
*Postpone the procedure so the patient can play*
- This option disregards the **immediate and severe risks** associated with hypertrophic cardiomyopathy during strenuous physical activity.
- Postponing the procedure for a game prioritizes a non-medical event over the patient's life-saving treatment, violating the principle of **patient safety**.
*Allow the patient to play and schedule a follow up after the game*
- This is medically irresponsible, as it exposes the patient to a high risk of **sudden cardiac arrest** during the game.
- Delaying urgent intervention for a non-medical reason fails to uphold the physician's obligation to protect the patient from **foreseeable harm**.
*Perform the procedure immediately so that both the physician and coach's wishes may be fulfilled*
- While performing the procedure immediately is medically sound, stating that the coach's wishes can be fulfilled is inaccurate if the player is being sidelined.
- The physician's advice to stop playing basketball stems from medical necessity, which directly conflicts with the coach's desire for the player to participate, thus **not fulfilling both wishes**.
*Allow the patient to make the decision regarding his health*
- While patient autonomy is important, a **16-year-old** is typically considered a minor and cannot make high-risk medical decisions without the consent of a **legal guardian**.
- In situations of significant risk to life, the physician has a responsibility to guide the patient and their guardians towards the safest medical option, rather than simply deferring to the patient's potentially uninformed decision.
Pacemakers and ICDs US Medical PG Question 2: 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
Pacemakers and ICDs 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.
Pacemakers and ICDs US Medical PG Question 3: A 67-year-old man presents to the emergency department for squeezing and substernal chest pain. He states that he was at home eating dinner when his symptoms began. The patient has a past medical history of diabetes, hypertension, and dyslipidemia. He is currently taking atorvastatin, lisinopril, insulin, metformin, metoprolol, and aspirin. Six days ago he underwent percutaneous coronary intervention. His temperature is 99.5°F (37.5°C), blood pressure is 197/118 mmHg, pulse is 120/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam reveals an uncomfortable elderly man who is sweating. An ECG is ordered. Which of the following is the best next step in management for this patient?
- A. Stress testing
- B. Angiography (Correct Answer)
- C. Cardiac troponins
- D. Creatine kinase-MB
- E. Myoglobin
Pacemakers and ICDs Explanation: ***Correct: Angiography***
- This patient presenting with **acute chest pain 6 days post-PCI** is at high risk for **stent thrombosis or acute in-stent restenosis**, which represents a life-threatening emergency.
- Given the **clinical instability** (severe hypertension 197/118, tachycardia 120/min, diaphoresis) and classic ACS symptoms in the immediate post-PCI period, **urgent coronary angiography** is the best next step in management.
- While ECG and troponins are important diagnostic tools, this patient requires **immediate intervention** to evaluate the recent PCI site and potentially perform emergent revascularization.
- In the setting of suspected **acute stent thrombosis**, time to reperfusion is critical, and angiography allows both diagnosis and treatment.
*Incorrect: Cardiac troponins*
- While troponins are essential biomarkers for myocardial injury and should be obtained, they are a **diagnostic test** rather than definitive management.
- Waiting for troponin results would delay definitive management in a patient with clear clinical evidence of ACS.
- In this high-risk post-PCI patient with active symptoms, management should not wait for biomarker confirmation.
*Incorrect: Stress testing*
- Stress testing is **absolutely contraindicated** in patients with active chest pain and suspected acute MI.
- It could precipitate further myocardial ischemia, arrhythmias, or cardiac arrest.
- Stress testing is reserved for risk stratification in stable patients or after ACS has been ruled out.
*Incorrect: Creatine kinase-MB*
- CK-MB is less sensitive and specific than troponins for myocardial injury, as it can be elevated in skeletal muscle conditions.
- It has a shorter elevation window and has largely been replaced by troponins in modern practice.
- Like troponins, it would not change the immediate management need in this clinically unstable patient.
*Incorrect: Myoglobin*
- Myoglobin lacks cardiac specificity (present in both cardiac and skeletal muscle) and has poor diagnostic accuracy for MI.
- Its rapid rise and fall make it unreliable, and it generates many false positives.
- It has no role in guiding management decisions in suspected ACS.
Pacemakers and ICDs US Medical PG Question 4: A 65-year-old woman is transferred to the intensive care unit after she underwent coronary stenting for a posterior-inferior STEMI. She is known to have allergies to amiodarone and captopril. A few hours after the transfer, she suddenly loses consciousness. The monitor shows ventricular fibrillation. CPR is initiated. After 3 consecutive shocks with a defibrillator, the monitor shows ventricular fibrillation. Which of the following medications should be administered next?
- A. Adrenaline and lidocaine (Correct Answer)
- B. Lidocaine and sotalol
- C. Adrenaline and verapamil
- D. Adrenaline and amiodarone
- E. Amiodarone and lidocaine
Pacemakers and ICDs Explanation: ***Adrenaline and lidocaine***
- **Adrenaline (epinephrine)** is the standard vasopressor in ACLS for cardiac arrest, given at 1 mg IV/IO every 3-5 minutes to increase coronary and cerebral perfusion pressures, improving the chances of return of spontaneous circulation (ROSC).
- **Lidocaine** is the recommended alternative antiarrhythmic for refractory ventricular fibrillation when **amiodarone is contraindicated** (as in this patient with documented amiodarone allergy).
- Per **ACLS guidelines**, after failed defibrillation attempts, continue CPR, administer epinephrine, and give an antiarrhythmic agent (lidocaine 1-1.5 mg/kg when amiodarone cannot be used).
*Lidocaine and sotalol*
- **Lidocaine** is appropriate as an antiarrhythmic in refractory VF when amiodarone is contraindicated.
- However, this option omits **epinephrine (adrenaline)**, which is a critical vasopressor required during cardiac arrest per ACLS protocols.
- **Sotalol** is a beta-blocker with Class III antiarrhythmic properties, but it is not recommended for acute management of refractory VF in cardiac arrest.
*Adrenaline and verapamil*
- **Adrenaline** is indicated as the vasopressor for cardiac arrest.
- **Verapamil** is a calcium channel blocker used for supraventricular arrhythmias; it is **contraindicated in ventricular fibrillation** due to negative inotropic effects and peripheral vasodilation that can worsen hemodynamic collapse during cardiac arrest.
*Adrenaline and amiodarone*
- While **adrenaline** is indicated and **amiodarone** would typically be the preferred antiarrhythmic for refractory VF, this patient has a **documented allergy to amiodarone**, making it contraindicated.
- Lidocaine must be used as the alternative antiarrhythmic agent.
*Amiodarone and lidocaine*
- **Lidocaine** is appropriate in this scenario.
- However, **amiodarone is contraindicated** due to the patient's known allergy.
- This combination would be dangerous and violates basic principles of avoiding known allergens.
Pacemakers and ICDs US Medical PG Question 5: A 71-year-old woman with a past medical history of type 2 diabetes, hypercholesterolemia, and hypertension was admitted to the hospital 8 hours ago with substernal chest pain for management of acute non-ST-elevated myocardial infarction (NSTEMI). The ECG findings noted by ST-depressions and T-wave inversions on anterolateral leads, which is also accompanied by elevated cardiac enzymes. Upon diagnosis, management with inhaled oxygen therapy, beta-blockers and aspirin, and low-molecular-weight heparin therapy were initiated, and she was placed on bed rest with continuous electrocardiographic monitoring. Since admission, she required 2 doses of sublingual nitroglycerin for recurrent angina, and the repeat troponin levels continued to rise. Given her risk factors, plans were made for early coronary angiography. The telemetry nurse calls the on-call physician because of her concern with the patient's mild confusion and increasing need for supplemental oxygen. At bedside evaluation, The vital signs include: heart rate 122/min, blood pressure 89/40 mm Hg, and the pulse oximetry is 91% on 6L of oxygen by nasal cannula. The telemetry and a repeat ECG show sinus tachycardia. She is breathing rapidly, appears confused, and complains of shortness of breath. On physical exam, the skin is cool and clammy and appears pale and dull. She has diffuse bilateral pulmonary crackles, and an S3 gallop is noted on chest auscultation with no new murmurs. She has jugular venous distention to the jaw-line, rapid and faint radial pulses, and 1+ dependent edema. She is immediately transferred to the intensive care unit for respiratory support and precautions for airway security. The bedside sonography shows abnormal hypodynamic anterior wall movement and an ejection fraction of 20%, but no evidence of mitral regurgitation or ventricular shunt. The chest X-ray demonstrates cephalization of pulmonary veins and pulmonary edema. What is the most appropriate next step in the stabilization of this patient?
- A. Obtain blood cultures and start preliminary broad-spectrum antibiotics
- B. Start intravenous fluids and epinephrine therapy
- C. Intubate the patient and perform an emergency cardiocentesis
- D. Initiate dopamine therapy and diuresis (Correct Answer)
- E. Insert two large-bore intravenous catheters and start rapid fluid resuscitation
Pacemakers and ICDs Explanation: ***Initiate dopamine therapy and diuresis***
- This patient is presenting with **cardiogenic shock** secondary to extensive NSTEMI, characterized by **hypotension**, signs of **end-organ hypoperfusion** (confusion, cool clammy skin), **pulmonary edema** (crackles, dyspnea, elevated jugular venous pressure), and **severely reduced ejection fraction**. Dopamine is a vasopressor that can increase cardiac output and blood pressure.
- **Diuresis** with loop diuretics such as furosemide is crucial to reduce the fluid overload contributing to the pulmonary edema and jugular venous distention.
*Obtain blood cultures and start preliminary broad-spectrum antibiotics*
- While infection is a concern in critically ill patients, there are **no signs of infection** in this clinical presentation. The patient's symptoms are clearly attributable to acute cardiac decompensation.
- A delay in treating cardiogenic shock to investigate for infection would be detrimental and potentially fatal.
*Start intravenous fluids and epinephrine therapy*
- Intravenous fluids would **worsen the existing pulmonary edema and fluid overload** in a patient with an ejection fraction of 20% and clinical signs of volume overload (crackles, JVD, S3 gallop).
- Epinephrine is a potent vasopressor but is generally reserved for more severe shock refractory to other inotropes, or in cases of **cardiac arrest**, not typically first-line for cardiogenic shock with significant pulmonary congestion.
*Intubate the patient and perform an emergency cardiocentesis*
- While the patient is confused and has respiratory distress, **intubation** should be considered after hemodynamic stabilization, if respiratory failure persists or worsens.
- **Cardiocentesis** is indicated for **cardiac tamponade**, which is not supported by the absence of an effusion on bedside sonography and the finding of hypodynamic anterior wall movement, which points to pump failure.
*Insert two large-bore intravenous catheters and start rapid fluid resuscitation*
- This patient is in **cardiogenic shock with clear evidence of fluid overload**, including pulmonary edema and elevated jugular venous pressure.
- **Rapid fluid resuscitation would exacerbate heart failure** and worsen respiratory compromise due to increased preload.
Pacemakers and ICDs US Medical PG Question 6: A 23-year-old man comes to the emergency department because of palpitations, dizziness, and substernal chest pain for three hours. The day prior, he was at a friend’s wedding, where he consumed seven glasses of wine. The patient appears diaphoretic. His pulse is 220/min and blood pressure is 120/84 mm Hg. Based on the patient's findings on electrocardiography, the physician diagnoses atrial fibrillation with rapid ventricular response and administers verapamil for rate control. Ten minutes later, the patient is unresponsive and loses consciousness. Despite resuscitative efforts, the patient dies. Histopathologic examination of the heart at autopsy shows an accessory atrioventricular conduction pathway. Electrocardiography prior to the onset of this patient's symptoms would most likely have shown which of the following findings?
- A. Epsilon wave following the QRS complex
- B. Prolongation of the QT interval
- C. Cyclic alteration of the QRS axis
- D. Slurred upstroke of the QRS complex (Correct Answer)
- E. Positive Sokolow-Lyon index
Pacemakers and ICDs Explanation: ***Slurred upstroke of the QRS complex***
- The patient's presentation with **atrial fibrillation with rapid ventricular response** and subsequent collapse after verapamil administration—a calcium channel blocker—is classic for a pre-excitation syndrome like **Wolff-Parkinson-White (WPW) syndrome**.
- In WPW, an accessory pathway (bundle of Kent) bypasses the AV node, leading to a **short PR interval** and a **delta wave** (slurred upstroke of the QRS complex) on ECG during normal sinus rhythm.
*Epsilon wave following the QRS complex*
- An **epsilon wave** is characteristic of **arrhythmogenic right ventricular cardiomyopathy (ARVC)**, representing delayed depolarization of the right ventricle.
- While ARVC can cause arrhythmias, it is distinctly different from the pre-excitation syndrome described, which involves an accessory pathway.
*Prolongation of the QT interval*
- **Prolonged QT interval** is associated with an increased risk of **torsades de pointes**, a polymorphic ventricular tachycardia.
- This finding is typical of **long QT syndrome** and does not directly relate to an accessory atrioventricular conduction pathway.
*Cyclic alteration of the QRS axis*
- **Cyclic alteration of the QRS axis** or electrical alternans is seen in conditions causing swings in cardiac position, most notably **pericardial effusion with tamponade**.
- This ECG finding is unrelated to accessory pathways or the mechanisms of pre-excitation syndromes.
*Positive Sokolow-Lyon index*
- A **positive Sokolow-Lyon index** signifies **left ventricular hypertrophy (LVH)**, characterized by large QRS voltages (e.g., SV1 + RV5/V6 ≥ 35 mm).
- While LVH can be associated with various cardiac conditions, it is not a direct ECG manifestation of an accessory atrioventricular conduction pathway.
Pacemakers and ICDs US Medical PG Question 7: A 54-year-old man with alcoholism comes to the emergency department because of vomiting blood for 6 hours. He has had 3–4 episodes in which he has vomited dark red blood during this period. He has had no epigastric pain or tarry stools. On arrival, his temperature is 37.3°C (99.1°F), pulse is 134/min, and blood pressure is 80/50 mm Hg. He is resuscitated with 0.9% saline and undergoes an emergency upper endoscopy, which shows actively bleeding varices. Band ligation of the varices is done and hemostasis is achieved. He is diagnosed with Child class B cirrhosis. He is concerned about the possibility of recurrence of such an episode. He is asked to abstain from alcohol, to which he readily agrees. In addition to non-selective beta-blocker therapy, which of the following is the most appropriate recommendation to prevent future morbidity and mortality from this condition?
- A. Terlipressin
- B. Transjugular intrahepatic portosystemic shunt
- C. Variceal sclerotherapy
- D. Variceal ligation (Correct Answer)
- E. Octreotide therapy
Pacemakers and ICDs Explanation: ***Variceal ligation***
- **Endoscopic variceal ligation (EVL) is the gold standard for secondary prophylaxis** (preventing re-bleeding) in patients who have already experienced a variceal hemorrhage.
- It involves placing elastic bands on varices to occlude them, leading to fibrosis and eradication of the varices.
*Terlipressin*
- **Terlipressin is a vasoconstrictor primarily used to control acute variceal bleeding**, not for long-term secondary prevention.
- It reduces portal pressure by causing splanchnic vasoconstriction but is not suitable for chronic management.
*Transjugular intrahepatic portosystemic shunt*
- **TIPS is typically reserved for patients who fail endoscopic and pharmacological therapies** or have refractory ascites.
- While effective in reducing portal pressure, it carries risks such as **hepatic encephalopathy** and is not the first-line secondary prevention strategy.
*Variceal sclerotherapy*
- **Variceal sclerotherapy involves injecting a sclerosant solution into or adjacent to varices to induce thrombosis and fibrosis.**
- It is an alternative to band ligation but is generally **less preferred for secondary prophylaxis due to a higher rate of complications** like esophageal ulceration and re-bleeding.
*Octreotide therapy*
- **Octreotide, a somatostatin analog, is used to reduce splanchnic blood flow and portal pressure during acute variceal bleeding episodes.**
- It is **not recommended for long-term secondary prophylaxis** and is typically used in conjunction with endoscopic therapy for acute management.
Pacemakers and ICDs US Medical PG Question 8: A 54-year-old woman comes to the emergency department because of two episodes of bright red blood per rectum within the past day. She has a history of migraine, which is treated prophylactically with verapamil. She appears well and is hemodynamically stable. Cardiac exam reveals a regular heart rate without any murmurs or gallops. Lungs are clear to auscultation. Her abdomen is mildly tender without rebound or guarding. Digital rectal examination shows fresh blood on the glove. Laboratory studies show:
Hemoglobin 10.4 g/dL
Leukocyte count 5,000/mm3
Platelet count 175,000/mm3
Partial thromboplastin time 35 seconds
Serum
Na+ 140 mEq/L
K+ 3.7 mEq/L
Cl- 101 mEq/L
HCO3- 25 mEq/L
Mg2+ 1.8 mEq/L
A routine ECG shows a heart rate of 75/min, a normal axis, PR interval of 280 ms, QRS interval of 80 ms with a QRS complex following each p wave, and no evidence of ischemic changes. Which of the following is the most appropriate next step in management with respect to this patient's cardiovascular workup?
- A. Observation (Correct Answer)
- B. Atropine therapy
- C. Synchronized cardioversion
- D. Metoprolol therapy
- E. Pacemaker placement
Pacemakers and ICDs Explanation: ***Observation***
- The patient is currently **hemodynamically stable** despite the prolonged PR interval, indicating that the **first-degree AV block** is not causing immediate compromise.
- Continuation of **verapamil** (a calcium channel blocker) for migraine prophylaxis is the likely cause of the prolonged PR interval; however, in the absence of symptoms attributable to the AV block, observation is appropriate.
*Atropine therapy*
- **Atropine** is used to increase heart rate in **symptomatic bradycardia** or higher-degree AV blocks (second or third-degree) if the patient is unstable.
- This patient is **hemodynamically stable** with a heart rate of 75/min and has only a first-degree AV block, making atropine unnecessary.
*Synchronized cardioversion*
- **Synchronized cardioversion** is reserved for **unstable tachyarrhythmias** or some unstable bradyarrhythmias not responsive to chemical therapy.
- The patient's heart rate is 75/min, and she has **no evidence of an arrhythmia** requiring cardioversion; her prolonged PR interval is a conduction delay, not an arrhythmia.
*Metoprolol therapy*
- **Metoprolol** is a beta-blocker that would **further slow AV nodal conduction** and could potentially worsen the first-degree AV block or precipitate a higher-degree block.
- It is contraindicated as a treatment for AV block and would exacerbate the underlying issue caused by verapamil.
*Pacemaker placement*
- **Pacemaker placement** is considered for **symptomatic second-degree or third-degree AV block**, or in some cases of first-degree AV block if it progresses to a higher degree and causes severe symptoms.
- This patient has a **first-degree AV block** and is **asymptomatic** and **hemodynamically stable**, thus a pacemaker is not indicated at this time.
Pacemakers and ICDs US Medical PG Question 9: A 22-year-old medical student presents to a community health center due to an episode of loss of consciousness 3 days ago. She also has a history of multiple episodes of dizziness in the last year. These episodes almost always occur when she is observing surgery in the operating room. She describes her dizziness as a feeling of lightheadedness, warmth, excessive sweating, and palpitations. She feels that she will fall down if she stood longer and usually sits on the floor or leaves the room until the feeling subsides. Three days ago, she collapsed while observing an open cholecystectomy but regained consciousness after a few seconds. Once she regained consciousness, she was pale and sweating excessively. Her medical history is significant for migraines, but she is not on prophylactic therapy. Her younger brother has cerebral palsy, and her uncle had a sudden death at the age of 25. Her blood pressure is 120/80 mm Hg when lying down and 118/80 mm Hg when in a standing position. The rest of the physical examination is within normal limits. What is the next best step in the management of this patient?
- A. Electroencephalogram (EEG)
- B. MRI of the brain
- C. Psychiatric evaluation for anxiety
- D. Echocardiogram
- E. Electrocardiogram (ECG) (Correct Answer)
Pacemakers and ICDs Explanation: ***Electrocardiogram (ECG)***
- This patient presents with recurrent episodes of near-syncope and a recent syncopal episode, triggered by a stressful situation (observing surgery), along with a family history of **sudden death at a young age** (uncle at 25). These red flags suggest a possible **cardiac etiology** for her syncope, such as a **long QT syndrome** or other channelopathies, making an ECG the most crucial initial investigation.
- An ECG is a **non-invasive, inexpensive, and readily available** test that can detect structural or electrical abnormalities of the heart that could predispose to arrhythmias and syncope.
*Electroencephalogram (EEG)*
- While loss of consciousness occurred, the clinical description of lightheadedness, warmth, sweating, and palpitations followed by syncope and quick recovery with post-recovery pallor and sweating is more consistent with **vasovagal syncope** or a cardiac cause, rather than a seizure.
- The absence of typical seizure features such as **tonic-clonic movements**, post-ictal confusion, or tongue biting makes epilepsy less likely.
*MRI of the brain*
- **Brain imaging** is generally not indicated for the initial workup of syncope unless there are focal neurological deficits, head trauma, or other symptoms suggestive of a central nervous system pathology.
- The patient's symptoms are classic for syncope and do not point to a **structural brain lesion** as the cause of her loss of consciousness.
*Psychiatric evaluation for anxiety*
- While anxiety can trigger vasovagal responses, the primary concern in this case, given the **recurrent nature of syncope** and the concerning **family history of sudden death**, is to rule out a potentially life-threatening cardiac cause before attributing it solely to psychological factors.
- Attributing syncope to anxiety without a thorough cardiac workup could delay diagnosis of a serious underlying condition.
*Echocardiogram*
- An echocardiogram assesses the **heart's structure and function**, which is important in the workup of syncope. However, it is typically performed *after* an ECG, especially if the ECG reveals abnormalities suggesting a structural or electrical problem.
- While it could be a subsequent step if the ECG is abnormal, the **ECG is the most immediate and informative initial step** for ruling out electrical cardiac issues.
Pacemakers and ICDs US Medical PG Question 10: A 46-year-old woman comes to the physician for a follow-up examination. She had a blood pressure recording of 148/94 mm Hg on her previous visit one week ago. Her home blood pressure log shows readings of 151/97 and 146/92 mm Hg in the past week. She has no history of serious illness and takes no medications. She is 160 cm (5 ft 3 in) tall and weighs 52 kg (115 lb); BMI is 20 kg/m2. Her pulse is 88/min and blood pressure is 150/96 mm Hg. Cardiopulmonary examination is unremarkable. Abdominal examination shows no abnormalities. The extremities are well perfused with strong peripheral pulses. Serum concentrations of electrolytes, creatinine, lipids, TSH, and fasting glucose are within the reference range. A urinalysis is within normal limits. Which of the following is the most appropriate next step in management?
- A. Echocardiography
- B. Renal ultrasonography
- C. Polysomnography
- D. Plasma renin activity
- E. Electrocardiogram (Correct Answer)
Pacemakers and ICDs Explanation: ***Electrocardiogram***
- An **electrocardiogram (ECG)** is essential for newly diagnosed hypertension to assess for **left ventricular hypertrophy (LVH)**, a common indicator of target-organ damage.
- Early detection of **LVH** can guide treatment intensity and is associated with increased cardiovascular risk.
*Echocardiography*
- While echocardiography can provide a more detailed assessment of **cardiac structure** and function, it is generally considered a second-line investigation for **LVH** after ECG in uncomplicated hypertension.
- ECG is a more cost-effective and readily available initial screening tool for **LVH**.
*Renal ultrasonography*
- **Renal ultrasonography** would be indicated if there were suspicious findings suggesting **renal artery stenosis**, such as refractory hypertension, an abdominal bruit, or unexplained decline in renal function.
- Her normal **creatinine** and **urinalysis** do not suggest kidney disease as an etiology for her hypertension.
*Polysomnography*
- **Polysomnography** is used to diagnose **sleep apnea**, which can be a cause or exacerbating factor of hypertension.
- The patient has no symptoms suggestive of **sleep apnea**, such as snoring, daytime somnolence, or witnessed apneic episodes.
*Plasma renin activity*
- **Plasma renin activity** is part of the workup for secondary hypertension, specifically to diagnose **primary hyperaldosteronism** or **renal artery stenosis**.
- Given the patient's normal electrolytes and absence of other red flags, screening for these conditions is not indicated as a first step.
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