A 70-year-old man comes to the physician because of a 6-month-history of worsening shortness of breath on exertion and bouts of coughing while sleeping. He has hypertension, hyperlipidemia, and type 2 diabetes mellitus. Current medications include lisinopril, simvastatin, and insulin. The patient appears tired but in no acute distress. His pulse is 70/min, blood pressure is 140/85 mm Hg, and respirations are 25/min. He has crackles over both lower lung fields and 2+ pitting edema of the lower extremities. An ECG shows T wave inversions in leads V1 to V4. Which of the following agents is most likely to improve the patient's long-term survival?
Q42
A 68-year-old man presents with shortness of breath, particularly when walking up stairs and when lying down to go to sleep at night. He also complains of a chronic cough and states that he now uses 2 extra pillows at night. The patient has a history of type 2 diabetes that is well-managed with metformin. He also takes Prozac for a long-standing history of depression. The patient has a 60-pack-year smoking history. He also has a history significant for alcohol abuse, but he quit cold turkey 15 years ago when his brother was killed in a drunk driving accident. Both he and his brother were adopted, and he does not know other members of his biological family. Despite repeated efforts of patient counseling, the patient is not interested in quitting smoking. The physical exam is significant for an obese male using accessory muscles of respiration. The vital signs include: temperature 36.8°C (98.2°F), heart rate 95/min, respiratory rate 16/min, and blood pressure 130/85 mm Hg. The oxygen saturation is 90% on room air. Additional physical exam findings include cyanotic lips, peripheral edema, hepatomegaly, and ascites. The cardiovascular exam is significant for an S3 heart sound and elevated JVP. The pulmonary exam is significant for expiratory wheezing, diffuse rhonchi, and hyperresonance on percussion. The laboratory test results are as follows:
BUN 15 mg/dL
pCO2 60 mm Hg
Bicarbonate (HCO3) 32 mmol/L
Creatinine 0.8 mg/dL
Glucose 95 mg/dL
Serum chloride 103 mmol/L
Serum potassium 3.9 mEq/L
Serum sodium 140 mEq/L
Total calcium 2.3 mmol/L
Hemoglobin 26 g/dL
Bilirubin total 0.9 mg/dL
Bilirubin indirect 0.4 mg/dL
Iron 100
Ferritin 70
TIBC 300
The posterior-anterior chest X-ray is shown in the image. Which of the following interventions is indicated for decreasing the mortality of this patient?
Q43
A 64-year-old male with a history of coronary artery disease, hypertension, hyperlipidemia, and type II diabetes presents to his primary care physician with increasing shortness of breath and ankle swelling over the past month. Which of the following findings is more likely to be seen in left-sided heart failure and less likely to be seen in right-sided heart failure?
Q44
A 58-year-old man comes to the physician because of a 5-day history of progressively worsening shortness of breath and fatigue. He has smoked 1 pack of cigarettes daily for 30 years. His pulse is 96/min, respirations are 26/min, and blood pressure is 100/60 mm Hg. An x-ray of the chest is shown. Which of the following is the most likely cause of this patient's findings?
Q45
A 65-year-old male presents to your office complaining of worsening shortness of breath. He has experienced shortness of breath on and off for several years, but is noticing that it is increasingly more difficult. Upon examination, you note wheezing and cyanosis. You conduct pulmonary function tests, and find that the patient's FEV1/FVC ratio is markedly decreased. What is the most likely additional finding in this patient?
Q46
A 55-year-old man presents to the emergency department with shortness of breath and fatigue. His symptoms began insidiously and progressively worsened over the course of a month. He becomes short of breath when climbing the stairs or performing low-intensity exercises. He also needs to rest on multiple pillows in order to comfortably sleep. A few weeks ago he developed fever, malaise, and chest pain. Medical history is significant for hypertension, hypercholesterolemia, type II diabetes, and bariatric surgery performed 10 years ago. He is taking lisinopril, atorvastatin, and metformin. He drinks alcohol occasionally and does not smoke. He tried cocaine 3 days ago for the first time and has not used the illicit drug since. Physical exam is significant for bibasilar crackles, an S3 heart sound, and a laterally displaced cardiac apex. He has normal muscle tone throughout, 2+ reflexes, and an intact sensory exam. Which of the following is most likely the cause of this patient's symptoms?
Q47
A 56-year-old man presents to the emergency department with increasing shortness of breath and mild chest discomfort. One week ago he developed cold-like symptoms, including a mild fever, headache, and occasional night sweats. He noticed that he required 2 additional pillows in order to sleep comfortably. Approximately 1-2 nights ago, he was severely short of breath, causing him to awaken from sleep which frightened him. He reports gaining approximately 6 pounds over the course of the week without any significant alteration to his diet. He says that he feels short of breath after climbing 1 flight of stairs or walking less than 1 block. Previously, he was able to climb 4 flights of stairs and walk 6-7 blocks with mild shortness of breath. Medical history is significant for coronary artery disease (requiring a left anterior descending artery stent 5 years ago and dual antiplatelet therapy), heart failure with reduced ejection fraction, hypertension, hyperlipidemia, and type II diabetes. He drinks 2 alcoholic beverages daily and has smoked 1 pack of cigarettes daily for the past 35 years. His temperature is 98.6°F (37°C), blood pressure is 145/90 mmHg, pulse is 102/min, and respirations are 20/min. On physical exam, the patient has a positive hepatojugular reflex, a third heart sound, crackles in the lung bases, and pitting edema up to the mid-thigh bilaterally. Which of the following is the best next step in management?
Q48
A 64-year-old man with longstanding ischemic heart disease presents to the clinic with complaints of increasing exercise intolerance and easy fatigability for the past 2 weeks. He further states that he has been experiencing excessive daytime somnolence and shortness of breath with exertion. His wife adds that his shortness of breath is more in the recumbent position, and after approximately 2 hours of sleep, after which he suddenly wakes up suffocating and gasping for breath. This symptom is relieved after assuming an upright position for more than 30 minutes. The vital signs are as follows: heart rate, 126/min; respiratory rate, 16/min; temperature, 37.6°C (99.6°F); and blood pressure, 122/70 mm Hg. The physical examination reveals a S3 gallop on cardiac auscultation and positive hepatojugular reflux with distended neck veins. An electrocardiogram shows ischemic changes similar to ECG changes noted in the past. An echocardiogram reveals an ejection fraction of 33%. Which of the following best describes the respiratory pattern abnormality which occurs in this patient while sleeping?
Q49
A 60-year-old male presents with fatigue, dyspnea on exertion, and lower extremity edema. Physical examination reveals an elevated jugular venous pressure and an S3 heart sound. Which of the following medications is most likely to improve this patient's symptoms?
Q50
A 51-year-old man comes to the physician because of progressively worsening dyspnea on exertion and fatigue for the past 2 months. Cardiac examination shows no murmurs or bruits. Coarse crackles are heard at the lung bases bilaterally. An ECG shows an irregularly irregular rhythm with absent p waves. An x-ray of the chest shows globular enlargement of the cardiac shadow with prominent hila and bilateral fluffy infiltrates. Transthoracic echocardiography shows a dilated left ventricle with an ejection fraction of 40%. Which of the following is the most likely cause of this patient's condition?
Heart failure US Medical PG Practice Questions and MCQs
Question 41: A 70-year-old man comes to the physician because of a 6-month-history of worsening shortness of breath on exertion and bouts of coughing while sleeping. He has hypertension, hyperlipidemia, and type 2 diabetes mellitus. Current medications include lisinopril, simvastatin, and insulin. The patient appears tired but in no acute distress. His pulse is 70/min, blood pressure is 140/85 mm Hg, and respirations are 25/min. He has crackles over both lower lung fields and 2+ pitting edema of the lower extremities. An ECG shows T wave inversions in leads V1 to V4. Which of the following agents is most likely to improve the patient's long-term survival?
A. Dobutamine
B. Amlodipine
C. Digoxin
D. Gemfibrozil
E. Metoprolol (Correct Answer)
Explanation: ***Metoprolol***
- The patient's symptoms (shortness of breath on exertion, coughing while sleeping, crackles, edema) and medical history (hypertension, hyperlipidemia, diabetes) point to **chronic heart failure with reduced ejection fraction (HFrEF)**. The patient is already on lisinopril (an ACE inhibitor), which is one cornerstone of HF therapy. Beta-blockers like metoprolol are another crucial medication class proven to improve **long-term survival in HFrEF** by reducing cardiac remodeling, myocardial oxygen demand, and arrhythmias.
- Metoprolol is a **selective beta-1 adrenergic blocker** that slows heart rate, reduces blood pressure, and decreases myocardial contractility, leading to improved cardiac efficiency and reduced mortality in chronic heart failure. The three beta-blockers with proven mortality benefit are metoprolol succinate, carvedilol, and bisoprolol.
*Dobutamine*
- **Dobutamine** is an inotropic agent used for **acute decompensated heart failure** to improve cardiac output and relieve symptoms in hospitalized patients.
- It does not improve long-term survival and is typically used in the short term for patients with severe systolic dysfunction and hypoperfusion or cardiogenic shock.
*Amlodipine*
- **Amlodipine** is a dihydropyridine calcium channel blocker primarily used for **hypertension and angina**.
- While it can lower blood pressure, it has **not been shown to improve long-term survival** in heart failure; some non-dihydropyridine calcium channel blockers (diltiazem, verapamil) may even worsen HF outcomes due to negative inotropic effects.
*Digoxin*
- **Digoxin** is a cardiac glycoside that improves symptoms and reduces hospitalizations in heart failure, particularly in patients with **atrial fibrillation** or persistent symptoms despite optimal therapy.
- However, it has **not been shown to improve long-term survival** in heart failure (DIG trial showed neutral mortality effect) and has a narrow therapeutic window requiring monitoring.
*Gemfibrozil*
- **Gemfibrozil** is a fibrate used to treat **hypertriglyceridemia**.
- It primarily affects lipid metabolism and has **no direct role in the management of heart failure** or in improving long-term survival in this context.
Question 42: A 68-year-old man presents with shortness of breath, particularly when walking up stairs and when lying down to go to sleep at night. He also complains of a chronic cough and states that he now uses 2 extra pillows at night. The patient has a history of type 2 diabetes that is well-managed with metformin. He also takes Prozac for a long-standing history of depression. The patient has a 60-pack-year smoking history. He also has a history significant for alcohol abuse, but he quit cold turkey 15 years ago when his brother was killed in a drunk driving accident. Both he and his brother were adopted, and he does not know other members of his biological family. Despite repeated efforts of patient counseling, the patient is not interested in quitting smoking. The physical exam is significant for an obese male using accessory muscles of respiration. The vital signs include: temperature 36.8°C (98.2°F), heart rate 95/min, respiratory rate 16/min, and blood pressure 130/85 mm Hg. The oxygen saturation is 90% on room air. Additional physical exam findings include cyanotic lips, peripheral edema, hepatomegaly, and ascites. The cardiovascular exam is significant for an S3 heart sound and elevated JVP. The pulmonary exam is significant for expiratory wheezing, diffuse rhonchi, and hyperresonance on percussion. The laboratory test results are as follows:
BUN 15 mg/dL
pCO2 60 mm Hg
Bicarbonate (HCO3) 32 mmol/L
Creatinine 0.8 mg/dL
Glucose 95 mg/dL
Serum chloride 103 mmol/L
Serum potassium 3.9 mEq/L
Serum sodium 140 mEq/L
Total calcium 2.3 mmol/L
Hemoglobin 26 g/dL
Bilirubin total 0.9 mg/dL
Bilirubin indirect 0.4 mg/dL
Iron 100
Ferritin 70
TIBC 300
The posterior-anterior chest X-ray is shown in the image. Which of the following interventions is indicated for decreasing the mortality of this patient?
A. Flu vaccine
B. Inhaled anticholinergics
C. ACE inhibitors
D. Smoking cessation alone
E. Both smoking cessation and oxygen administration (Correct Answer)
Explanation: **Both smoking cessation and oxygen administration**
- Given the patient's **60-pack-year smoking history**, current respiratory symptoms, and **hypoxemia** (SpO2 90% on room air), **smoking cessation is the single most important intervention to slow the progression of chronic obstructive pulmonary disease (COPD)**.
- **Long-term oxygen therapy (LTOT)** has been shown to **reduce mortality in COPD patients with chronic hypoxemia**. The patient's oxygen saturation of 90% on room air meets the criteria for LTOT.
*Flu vaccine*
- While **influenza vaccination is crucial for preventing exacerbations and reducing morbidity in COPD patients**, it does not directly decrease overall mortality from the underlying disease in the same way as smoking cessation and oxygen therapy.
- It is a recommended prophylactic measure for patients with chronic respiratory conditions, but its impact on all-cause mortality is less direct than the key interventions mentioned.
*Inhaled anticholinergics*
- **Inhaled anticholinergics (e.g., tiotropium)** are bronchodilators that help **improve lung function and reduce symptoms** in COPD, but they do not alter the disease's natural progression or directly reduce mortality.
- They are a cornerstone of **symptomatic management** for COPD but are not considered a mortality-reducing intervention.
*ACE inhibitors*
- **Angiotensin-converting enzyme (ACE) inhibitors** are primarily used in conditions like **hypertension, heart failure, and chronic kidney disease**.
- Although the patient has signs of right-sided heart failure (peripheral edema, hepatomegaly, ascites), which could be secondary to severe COPD (cor pulmonale), ACE inhibitors are **not indicated as a primary treatment for COPD itself** or **to reduce mortality in this context**.
*Smoking cessation alone*
- While **smoking cessation is the most important intervention to slow COPD progression and reduce mortality**, the patient's current **hypoxemia (SpO2 90%) also warrants oxygen administration** for mortality benefit.
- Therefore, **smoking cessation combined with oxygen administration** offers a more comprehensive approach to reducing mortality in this patient.
Question 43: A 64-year-old male with a history of coronary artery disease, hypertension, hyperlipidemia, and type II diabetes presents to his primary care physician with increasing shortness of breath and ankle swelling over the past month. Which of the following findings is more likely to be seen in left-sided heart failure and less likely to be seen in right-sided heart failure?
A. Abdominal fullness
B. Basilar crackles on pulmonary auscultation (Correct Answer)
C. Hepatojugular reflex
D. Increased ejection fraction on echocardiogram
E. Lower extremity edema
Explanation: ***Basilar crackles on pulmonary auscultation***
- **Left-sided heart failure** leads to increased pressure in the pulmonary veins, causing fluid to leak into the **pulmonary interstitium and alveoli**, manifesting as **basilar crackles** on auscultation.
- This symptom is a direct result of **pulmonary congestion** and edema, which is not characteristic of isolated right-sided heart failure.
*Abdominal fullness*
- **Abdominal fullness** is typically a symptom of **right-sided heart failure**, due to **venous congestion** in the splanchnic circulation, leading to hepatomegaly and ascites.
- While it can occur in severe biventricular failure, it is not a primary or earlier sign of isolated left-sided heart failure.
*Hepatojugular reflex*
- The **hepatojugular reflex** is a sign of **right ventricular dysfunction** and **elevated right atrial pressure**, indicating systemic venous congestion.
- It is elicited by applying pressure to the liver, which causes a temporary increase in jugular venous distention.
*Increased ejection fraction on echocardiogram*
- **Heart failure**, whether left- or right-sided, is characterized by a **reduced (or preserved but not increased)** ejection fraction, reflecting impaired pumping ability.
- An **increased ejection fraction** would indicate supra-normal cardiac function and is not associated with heart failure.
*Lower extremity edema*
- **Lower extremity edema** is a hallmark symptom of **right-sided heart failure**, as venous congestion leads to fluid accumulation in the peripheral tissues.
- While present in biventricular failure, it is not a primary or early symptom of isolated left-sided heart failure.
Question 44: A 58-year-old man comes to the physician because of a 5-day history of progressively worsening shortness of breath and fatigue. He has smoked 1 pack of cigarettes daily for 30 years. His pulse is 96/min, respirations are 26/min, and blood pressure is 100/60 mm Hg. An x-ray of the chest is shown. Which of the following is the most likely cause of this patient's findings?
A. Acute respiratory distress syndrome
B. Interstitial pneumonia
C. Tricuspid regurgitation
D. Pulmonary embolism
E. Left ventricular failure (Correct Answer)
Explanation: ***Left ventricular failure***
- The chest x-ray shows diffuse **pulmonary edema** with **bilateral perihilar infiltrates** and prominent **vascular markings**, classic for **cardiogenic pulmonary edema** due to left ventricular failure.
- The patient's history of smoking, shortness of breath, fatigue, tachypnea, and hypotension are consistent with **acute decompensated heart failure**.
*Acute respiratory distress syndrome*
- While ARDS can cause diffuse pulmonary infiltrates, it's often more peripheral and patchy; the presented image shows a more **central perihilar distribution** typical of pulmonary edema.
- ARDS is usually characterized by a severe inflammatory response, often without the marked **cardiomegaly** that would suggest a primary cardiac cause.
*Interstitial pneumonia*
- Interstitial pneumonia typically presents with **reticular or nodular patterns** on chest x-ray, often with a more chronic course.
- The acute onset and rapid progression of symptoms, along with the specific pattern of pulmonary edema, make interstitial pneumonia less likely.
*Tricuspid regurgitation*
- **Tricuspid regurgitation** primarily affects the right side of the heart, leading to signs of **right heart failure** such as **venous congestion**, **hepatomegaly**, and **peripheral edema**.
- While it can indirectly contribute to pulmonary hypertension and congestion, it would not typically present with this specific appearance of **cardiogenic pulmonary edema** without significant left ventricular involvement.
*Pulmonary embolism*
- A **pulmonary embolism** typically causes **pleural effusions**, areas of **oligemia (Westermark sign)**, or **wedge-shaped infiltrates (Hampton hump)**, but rarely diffuse pulmonary edema.
- The patient's acute symptoms could be consistent with PE, but the x-ray findings are not typical for this condition.
Question 45: A 65-year-old male presents to your office complaining of worsening shortness of breath. He has experienced shortness of breath on and off for several years, but is noticing that it is increasingly more difficult. Upon examination, you note wheezing and cyanosis. You conduct pulmonary function tests, and find that the patient's FEV1/FVC ratio is markedly decreased. What is the most likely additional finding in this patient?
A. Decreased serum bicarbonate
B. Increased IgE
C. Increased erythropoietin (Correct Answer)
D. Pleural effusion
E. Nasal polyps
Explanation: **Increased erythropoietin**
- The patient's presentation of worsening **shortness of breath**, **wheezing**, and **cyanosis**, along with a **markedly decreased FEV1/FVC ratio**, indicates a severe **obstructive lung disease**, likely **COPD**.
- **Chronic hypoxemia** (due to impaired gas exchange in severe obstructive lung disease) stimulates the kidneys to produce more **erythropoietin**, leading to secondary **polycythemia** to increase oxygen-carrying capacity.
*Decreased serum bicarbonate*
- **Decreased serum bicarbonate** typically indicates **metabolic acidosis**, which is not a primary or direct consequence of chronic obstructive lung disease.
- In chronic respiratory conditions, the body often compensates for **respiratory acidosis** by **increasing bicarbonate retention**, leading to a normal or increased bicarbonate level.
*Increased IgE*
- **Elevated IgE** levels are characteristic of **atopic conditions** like **asthma** or allergic reactions, which are not explicitly suggested as the primary issue in this patient's chronic and progressive symptoms.
- While asthma can have an obstructive pattern, the description of chronic worsening symptoms and cyanosis points more towards **COPD**, where IgE is not typically a direct distinguishing factor.
*Pleural effusion*
- **Pleural effusion** is an accumulation of fluid in the pleural space and would typically present with **dullness to percussion** and **decreased breath sounds** over the affected area, not primarily wheezing.
- While some lung conditions can be complicated by pleural effusion, it is not a direct or most likely additional finding based on the presented symptoms of obstructive lung disease.
*Nasal polyps*
- **Nasal polyps** are benign growths in the nasal passages and are often associated with conditions like **aspirin-exacerbated respiratory disease** or **chronic rhinosinusitis**.
- They are not a direct or common additional finding in the context of the severe and chronic obstructive lung disease described with systemic hypoxemia.
Question 46: A 55-year-old man presents to the emergency department with shortness of breath and fatigue. His symptoms began insidiously and progressively worsened over the course of a month. He becomes short of breath when climbing the stairs or performing low-intensity exercises. He also needs to rest on multiple pillows in order to comfortably sleep. A few weeks ago he developed fever, malaise, and chest pain. Medical history is significant for hypertension, hypercholesterolemia, type II diabetes, and bariatric surgery performed 10 years ago. He is taking lisinopril, atorvastatin, and metformin. He drinks alcohol occasionally and does not smoke. He tried cocaine 3 days ago for the first time and has not used the illicit drug since. Physical exam is significant for bibasilar crackles, an S3 heart sound, and a laterally displaced cardiac apex. He has normal muscle tone throughout, 2+ reflexes, and an intact sensory exam. Which of the following is most likely the cause of this patient's symptoms?
A. Medication side-effect
B. Cocaine use
C. Alcohol use
D. Enterovirus (Correct Answer)
E. Bariatric surgery
Explanation: ***Enterovirus***
- This patient presents with classic **viral myocarditis** progressing to **dilated cardiomyopathy**. The timeline is key: **prodromal viral illness** (fever, malaise, chest pain) a few weeks ago, followed by **progressive heart failure symptoms** over the subsequent month.
- **Enteroviruses** (particularly Coxsackievirus B) are the most common cause of viral myocarditis in developed countries, accounting for 25-35% of cases.
- Clinical findings of **dilated cardiomyopathy** (S3 heart sound, laterally displaced apex, bibasilar crackles, orthopnea) developing after a viral prodrome strongly support this diagnosis.
- The patient's cardiovascular risk factors (HTN, hypercholesterolemia, DM) may have made him more susceptible to myocardial injury.
*Cocaine use*
- While cocaine can cause acute coronary syndrome, myocardial infarction, and cardiomyopathy, the **timeline does not fit**: the patient used cocaine **3 days ago** but symptoms began **1 month ago**.
- Cocaine-induced cardiomyopathy typically requires **chronic use**, not a single exposure.
- The cocaine use appears to be **incidental** or possibly a misguided attempt to cope with fatigue, rather than the primary etiology.
*Medication side-effect*
- The patient's medications (lisinopril, atorvastatin, metformin) are not associated with dilated cardiomyopathy.
- **Lisinopril** is an ACE inhibitor used to *treat* heart failure, while atorvastatin and metformin have favorable or neutral cardiac profiles.
*Alcohol use*
- **Alcoholic cardiomyopathy** requires **chronic heavy consumption** (typically >7-8 drinks/day for >5 years).
- This patient reports only **occasional alcohol use**, making this diagnosis extremely unlikely.
*Bariatric surgery*
- While nutritional deficiencies post-bariatric surgery can cause cardiac complications (e.g., **thiamine deficiency** leading to wet beriberi), this typically presents as **high-output heart failure** rather than the **low-output dilated cardiomyopathy** seen here.
- The surgery occurred **10 years ago**, making acute nutritional deficiency less likely without other supporting evidence.
Question 47: A 56-year-old man presents to the emergency department with increasing shortness of breath and mild chest discomfort. One week ago he developed cold-like symptoms, including a mild fever, headache, and occasional night sweats. He noticed that he required 2 additional pillows in order to sleep comfortably. Approximately 1-2 nights ago, he was severely short of breath, causing him to awaken from sleep which frightened him. He reports gaining approximately 6 pounds over the course of the week without any significant alteration to his diet. He says that he feels short of breath after climbing 1 flight of stairs or walking less than 1 block. Previously, he was able to climb 4 flights of stairs and walk 6-7 blocks with mild shortness of breath. Medical history is significant for coronary artery disease (requiring a left anterior descending artery stent 5 years ago and dual antiplatelet therapy), heart failure with reduced ejection fraction, hypertension, hyperlipidemia, and type II diabetes. He drinks 2 alcoholic beverages daily and has smoked 1 pack of cigarettes daily for the past 35 years. His temperature is 98.6°F (37°C), blood pressure is 145/90 mmHg, pulse is 102/min, and respirations are 20/min. On physical exam, the patient has a positive hepatojugular reflex, a third heart sound, crackles in the lung bases, and pitting edema up to the mid-thigh bilaterally. Which of the following is the best next step in management?
A. Nitroprusside
B. Bumetanide (Correct Answer)
C. Carvedilol
D. Milrinone
E. Dopamine
Explanation: ***Bumetanide***
- The patient presents with classic signs and symptoms of **acute decompensated heart failure** (ADHF) including progressive dyspnea, orthopnea, paroxysmal nocturnal dyspnea, recent weight gain, pitting edema, crackles, an S3 gallop, and a positive hepatojugular reflex.
- **Loop diuretics** like bumetanide are the cornerstone of ADHF management due to their potent diuretic effect, which reduces **preload** by removing excess fluid and rapidly alleviates pulmonary and systemic congestion.
*Nitroprusside*
- This is a **venous and arterial vasodilator** used to reduce both preload and afterload in severe heart failure with elevated blood pressure or concomitant acute myocardial infarction.
- While it can be used in ADHF, it is typically reserved for cases with severe hypertension or persistent congestion despite diuretics, or when an immediate reduction in afterload is critical, which is not explicitly indicated as the *best initial step* given the primary presentation of fluid overload responsive to diuresis.
*Carvedilol*
- **Beta-blockers** like carvedilol are essential for long-term management of chronic heart failure, improving survival and reducing hospitalizations.
- However, they are generally **contraindicated or must be used with extreme caution** in the setting of acute decompensated heart failure due to their negative inotropic effects, which can worsen cardiac function and symptoms.
*Milrinone*
- Milrinone is a **phosphodiesterase-3 inhibitor** that provides positive inotropic effects (increasing contractility) and vasodilation.
- It is typically used in patients with severe ADHF who have **low cardiac output** and are unresponsive to conventional therapy, or in those with significant renal dysfunction, but it can cause hypotension and arrhythmias.
*Dopamine*
- Dopamine is a **catecholamine** with dose-dependent effects; at low doses, it enhances renal perfusion, and at higher doses, it provides positive inotropic and vasopressor effects.
- It is primarily used in **cardiogenic shock** or refractory hypotension associated with ADHF to support blood pressure and improve cardiac output, but its use is associated with arrhythmias and increased myocardial oxygen demand.
Question 48: A 64-year-old man with longstanding ischemic heart disease presents to the clinic with complaints of increasing exercise intolerance and easy fatigability for the past 2 weeks. He further states that he has been experiencing excessive daytime somnolence and shortness of breath with exertion. His wife adds that his shortness of breath is more in the recumbent position, and after approximately 2 hours of sleep, after which he suddenly wakes up suffocating and gasping for breath. This symptom is relieved after assuming an upright position for more than 30 minutes. The vital signs are as follows: heart rate, 126/min; respiratory rate, 16/min; temperature, 37.6°C (99.6°F); and blood pressure, 122/70 mm Hg. The physical examination reveals a S3 gallop on cardiac auscultation and positive hepatojugular reflux with distended neck veins. An electrocardiogram shows ischemic changes similar to ECG changes noted in the past. An echocardiogram reveals an ejection fraction of 33%. Which of the following best describes the respiratory pattern abnormality which occurs in this patient while sleeping?
A. Decreased central hypercapnic ventilatory responsiveness
B. Increased pulmonary artery pressure
C. Decreased sympathetic activity
D. Increased partial pressure of oxygen
E. Prolonged lung-to-brain circulation time (Correct Answer)
Explanation: ***Prolonged lung-to-brain circulation time***
- The patient's symptoms, including **paroxysmal nocturnal dyspnea (PND)** and **Cheyne-Stokes respiration (CSR)**, are characteristic of **heart failure (HF)**. In HF, a **reduced cardiac output** leads to a **prolonged lung-to-brain circulation time**.
- This delay results in a lag between changes in blood gas levels at the lungs and their detection by central chemoreceptors in the brainstem, causing an **oscillatory ventilatory pattern**, where episodes of hyperpnea (over-breathing) and apnea (cessation of breathing) alternate.
*Decreased central hypercapnic ventilatory responsiveness*
- This would lead to **hypoventilation** and **hypercapnia (elevated CO2)**, not the alternating hyperpnea and apnea seen in **Cheyne-Stokes respiration**, which is driven by chemoreceptor instability.
- While patients with **severe chronic obstructive pulmonary disease (COPD)** can have decreased hypercapnic responsiveness, it does not explain the distinct pattern of **PND** and **CSR** observed here.
*Increased pulmonary artery pressure*
- **Increased pulmonary artery pressure (pulmonary hypertension)** is a common consequence of **heart failure** and contributes to dyspnea. However, it does not directly explain the specific **oscillatory breathing pattern** or the sudden awakening with suffocation.
- While it exacerbates respiratory symptoms, the primary mechanism of **Cheyne-Stokes respiration** relates to circulatory delay and chemoreceptor feedback.
*Decreased sympathetic activity*
- **Decreased sympathetic activity** would generally lead to a **slower heart rate** and **relaxation of airways**, which is contrary to the **tachycardia** (HR 126/min) and severe respiratory distress seen in the patient's presentation.
- **Heart failure**, especially when decompensated, is often associated with **increased sympathetic activity** as a compensatory mechanism.
*Increased partial pressure of oxygen*
- An **increased partial pressure of oxygen (PaO2)** would alleviate hypoxia and improve breathing, rather than causing **dyspnea** and a complex respiratory pattern like **Cheyne-Stokes respiration**.
- Patients with **heart failure** often experience **hypoxemia** due to pulmonary congestion, making an increased PaO2 an unlikely contributing factor to their respiratory distress.
Question 49: A 60-year-old male presents with fatigue, dyspnea on exertion, and lower extremity edema. Physical examination reveals an elevated jugular venous pressure and an S3 heart sound. Which of the following medications is most likely to improve this patient's symptoms?
A. Metoprolol
B. Furosemide (Correct Answer)
C. Losartan
D. Lisinopril
E. Spironolactone
Explanation: ***Correct: Furosemide***
- The patient presents with classic signs of **heart failure with fluid overload**: dyspnea on exertion, lower extremity edema, elevated jugular venous pressure, and an S3 heart sound (indicating volume overload).
- **Furosemide**, a **loop diuretic**, is the most effective medication for **rapid symptomatic relief** in heart failure with congestion. It works by blocking sodium and water reabsorption in the loop of Henle, promoting diuresis and reducing **pulmonary congestion** and **peripheral edema**.
- While other medications like ACE inhibitors, beta-blockers, and aldosterone antagonists are crucial for **long-term mortality reduction** and disease modification, loop diuretics provide the **fastest and most direct symptomatic improvement** for fluid overload.
*Incorrect: Metoprolol*
- **Metoprolol** is a **beta-blocker** that is essential for chronic HFrEF management, providing **mortality reduction** and **reverse cardiac remodeling**.
- However, beta-blockers take **weeks to months** to show symptomatic benefit and can initially **worsen symptoms** due to negative inotropic effects, especially in acute decompensation.
- While important for long-term management, metoprolol does not provide immediate symptomatic relief from fluid overload.
*Incorrect: Losartan*
- **Losartan** is an **angiotensin receptor blocker (ARB)** used as an alternative to ACE inhibitors in HFrEF, particularly in patients who develop cough with ACE inhibitors.
- ARBs reduce **afterload** and prevent **cardiac remodeling**, contributing to improved long-term outcomes and mortality reduction.
- However, they do not directly address fluid overload and do not provide rapid symptomatic relief compared to diuretics.
*Incorrect: Spironolactone*
- **Spironolactone** is an **aldosterone antagonist** that improves mortality in HFrEF by preventing myocardial fibrosis, reducing cardiac remodeling, and preventing potassium loss.
- While beneficial for long-term management, spironolactone has **weak diuretic effects** and takes weeks to provide symptomatic benefit.
- It is not the first-line choice for **acute symptomatic relief** of volume overload, though it is an important component of chronic HFrEF therapy.
*Incorrect: Lisinopril*
- **Lisinopril** is an **ACE inhibitor** and a cornerstone of HFrEF therapy, reducing **mortality**, **hospitalizations**, and preventing **cardiac remodeling** by reducing afterload and preload.
- While ACE inhibitors improve symptoms over time, they do not provide the **rapid diuretic effect** needed for immediate relief of dyspnea and edema.
- Lisinopril is essential for long-term management but is not the most effective option for acute symptomatic improvement of fluid overload.
Question 50: A 51-year-old man comes to the physician because of progressively worsening dyspnea on exertion and fatigue for the past 2 months. Cardiac examination shows no murmurs or bruits. Coarse crackles are heard at the lung bases bilaterally. An ECG shows an irregularly irregular rhythm with absent p waves. An x-ray of the chest shows globular enlargement of the cardiac shadow with prominent hila and bilateral fluffy infiltrates. Transthoracic echocardiography shows a dilated left ventricle with an ejection fraction of 40%. Which of the following is the most likely cause of this patient's condition?
A. Acute psychological stress
B. Deposition of misfolded proteins
C. Inherited β-myosin heavy chain mutation
D. Uncontrolled essential hypertension
E. Tachycardia-induced cardiomyopathy secondary to atrial fibrillation (Correct Answer)
Explanation: ***Tachycardia-induced cardiomyopathy secondary to atrial fibrillation***
- The patient presents with **progressively worsening dyspnea on exertion** and **fatigue**, along with signs of **heart failure** (globular cardiac shadow, prominent hila, bilateral fluffy infiltrates).
- The **ECG finding of an irregularly irregular rhythm with absent P waves** is characteristic of **atrial fibrillation**, and a dilated left ventricle with an **ejection fraction of 40%** indicates **dilated cardiomyopathy**, which can be caused by chronic tachycardia in atrial fibrillation.
*Acute psychological stress*
- Acute psychological stress can lead to **Takotsubo cardiomyopathy** (stress-induced cardiomyopathy), which typically presents with **transient left ventricular apical ballooning** and preserved basal contractility, not necessarily a globally dilated left ventricle in this context.
- While it can cause heart failure symptoms, the **chronic nature** of the symptoms (2 months) and the presence of **atrial fibrillation** make it a less likely primary cause here.
*Deposition of misfolded proteins*
- **Amyloidosis**, characterized by the deposition of misfolded proteins, primarily causes **restrictive cardiomyopathy**, leading to impaired diastolic filling rather than primarily systolic dysfunction with a dilated ventricle.
- While amyloidosis can manifest with HF symptoms, the echocardiographic finding of a **dilated left ventricle** and the strong evidence for atrial fibrillation contributing to tachycardia-induced cardiomyopathy make this less likely.
*Inherited β-myosin heavy chain mutation*
- This mutation is classically associated with **hypertrophic cardiomyopathy**, characterized by **left ventricular hypertrophy** and impaired diastolic function, often with a normal or increased ejection fraction initially.
- The patient's echocardiogram shows a **dilated left ventricle** with reduced ejection fraction, which is inconsistent with typical hypertrophic cardiomyopathy.
*Uncontrolled essential hypertension*
- Chronic uncontrolled hypertension typically leads to **hypertensive heart disease**, initially causing **left ventricular hypertrophy** and eventual **diastolic dysfunction**, before progressing to dilated cardiomyopathy in very advanced stages.
- While possible, the prominent **irregularly irregular rhythm with absent P waves** guiding towards atrial fibrillation as a direct cause of tachycardia-induced cardiomyopathy makes it a more specific and likely cause in this scenario.