A 71-year old man is brought to the emergency department because of progressively worsening shortness of breath and fatigue for 3 days. During the last month, he has also noticed dark colored urine. He had an upper respiratory infection 6 weeks ago. He underwent a cholecystectomy at the age of 30 years. He has hypertension, hyperlipidemia, and type 2 diabetes mellitus. He immigrated to the US from Italy 50 years ago. Current medications include simvastatin, lisinopril, and metformin. He appears pale. His temperature is 37.1°C (98.8°F), pulse is 96/min, respirations are 21/min, and blood pressure is 150/80 mm Hg. Auscultation of the heart shows a grade 4/6 systolic murmur over the right second intercostal space that radiates to the carotids. Laboratory studies show: Leukocyte count 9,000/mm3 Hemoglobin 8.3 g/dL Hematocrit 24% Platelet count 180,000/mm3 LDH 212 U/L Haptoglobin 15 mg/dL (N=41–165) Serum Na+ 138 mEq/L K+ 4.5 mEq/L CL- 102 mEq/L HCO3- 24 mEq/L Urea nitrogen 20 mg/dL Creatinine 1.2 mg/dL Total bilirubin 1.8 mg/dL Stool testing for occult blood is negative. Direct Coombs test is negative. Echocardiography shows an aortic jet velocity of 4.2 m/s and a mean pressure gradient of 46 mm Hg. Which of the following is the most appropriate next step in management to treat this patient's anemia?

Administration of corticosteroids

A 72-year-old man is taken to the emergency room after losing consciousness. According to his wife, he suddenly complained of fluttering in his chest, lightheadedness, and profuse sweating while walking to the grocery store. He then turned gray, lost consciousness, and collapsed onto the ground. His medical history is significant for a prior anterior wall myocardial infarction 2 years ago that was complicated by severe left ventricular systolic dysfunction. His blood pressure is 80/50 mm Hg, the temperature is 36.7°C (98.0°F), and the carotid pulse is not palpable. An ECG was obtained and the results are shown in the picture. Cardiopulmonary resuscitation is initiated and the patient is cardioverted to sinus rhythm with an external defibrillator. The patient regains consciousness and states there was no antecedent chest discomfort. Cardiac enzymes are negative and serum electrolytes are normal. Which of the following is the best next step for this patient?

Implantable cardioverter-defibrillator

Temporary or permanent cardiac pacing

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?

Initiate dopamine therapy and diuresis

Obtain blood cultures and start preliminary broad-spectrum antibiotics

Start intravenous fluids and epinephrine therapy

Intubate the patient and perform an emergency cardiocentesis

Insert two large-bore intravenous catheters and start rapid fluid resuscitation

A 62-year-old man with a past medical history of previous myocardial infarction, angina, hypertension, hyperlipidemia, diabetes mellitus, peripheral vascular disease, and below knee amputation has developed new chest pain. His medication includes insulin, hydrochlorothiazide, lisinopril, metoprolol, daily aspirin, atorvastatin, and nitroglycerin as needed. His vitals include: blood pressure 135/87 mm Hg, pulse 52/min, and respirations 17/min. Coronary arteriography shows a reduced ejection fraction, a 65% stenosis of the left anterior descending artery, and a 75% stenosis of the left circumflex artery. Which of the following is the recommended treatment for the patient?

Coronary artery bypass grafting (CABG)

Angioplasty with stent placement

Extended release nitrate therapy

A 58-year-old man is brought to the Emergency Department after 2 days of shortness of breath, orthopnea, and lower limb edema. His past medical history is significant for hypertension and a myocardial infarction 3 years ago that required a coronary arterial bypass graft. He has not been able to take prescribed medicine in several months due to recent unemployment and issues with insurance. On admission, his blood pressure is 155/92 mmHg, heart rate is 102/min, respiratory rate is 24/min, and temperature is 36.4°C (97.5°F). On physical examination there are fine rales in both lungs, regular and rhythmic cardiac sounds with an S3 gallop and a grade II/VI holosystolic murmur. Initial laboratory tests are shown below: Na+ 140 mEq/L K+ 4.2 mEq/L Cl- 105 mEq/L BUN 20 mg/dL Creatinine 0.8 mg/dL The patient is stabilized and admitted to the hospital. The next day his blood pressure is 110/60 mmHg, heart rate is 110/min, respiratory rate is 18/min, and temperature is 36.4°C (97.5°F). This morning's laboratory tests are shown below: Na+ 135 mEq/L K+ 3.2 mEq/L Cl- 102 mEq/L BUN 45 mg/dL Creatinine 1.7 mg/dL Which of the following best explains the changes seen in this patient?

Glomerular basement membrane damage

A 55-year-old woman presents with fatigue, shortness of breath during ordinary activities, and occasional fluttering in her chest. She denies chest pain or lower extremity edema. She has no prior medical history. She does not smoke but drinks alcohol socially. Her blood pressure is 110/70 mm Hg, her temperature is 36.9°C (98.4°F), and her radial pulse is 95/min and regular. On physical examination, lungs are clear to auscultation, the apical impulse is slightly displaced, and a III/VI holosystolic murmur is audible at the apex and radiates to the axilla. Transthoracic echocardiography shows the presence of mitral regurgitation and an ejection fraction of 60 %. Which of the following is the optimal therapy for this patient?

ACE inhibitors, beta-blockers, diuretics, and surgery

Intra-aortic balloon counterpulsation

Observation and echocardiographic followup

Angiotensin-converting enzyme (ACE) inhibitors and beta-blockers

Device therapy for heart failure for USMLE Step 1: High-Yield Internal Medicine Lessons

ICDs - Shocking Rhythms Right

Primary Prevention of SCD:
- Reduces mortality in HFrEF (NYHA II-III) with LVEF ≤ 35% despite ≥3 months of optimal medical therapy (OMT).
- Also for post-MI (>40 days) with LVEF ≤ 30%.
- Patient must have a reasonable expectation of survival > 1 year.
Secondary Prevention of SCD:
- Survivors of cardiac arrest from ventricular tachycardia (VT) or fibrillation (VF).
- Spontaneous sustained VT.
Mechanism:
- Detects fatal arrhythmias (VT/VF).
- Delivers a high-energy shock to defibrillate.
- Can also use anti-tachycardia pacing (ATP).

⭐ ICD placement is delayed for at least 40 days post-MI and 90 days post-revascularization (PCI/CABG) to allow for potential LV function recovery and avoid treating transient electrical instability.

CRT - Syncing Up the Squeeze

Goal: Corrects electrical dyssynchrony (e.g., LBBB) to improve the mechanical efficiency of the heart's contraction. It's essentially a "biventricular pacemaker."
Core Indications:
- NYHA Class II-IV symptoms on optimal medical therapy.
- LVEF ≤ 35%.
- Wide QRS complex ≥ 150 ms, particularly with LBBB morphology.
Mechanism: Paces both right and left ventricles simultaneously, restoring a coordinated squeeze. The LV lead is typically placed via the coronary sinus.
Outcomes: Improves symptoms, reduces HF hospitalizations, promotes reverse LV remodeling, and provides a mortality benefit.

⭐ High-Yield: The presence of a Left Bundle Branch Block (LBBB) is the strongest ECG predictor of a positive clinical response to CRT.

Cardiac Resynchronization Therapy (CRT) Lead Placement

LVADs - The Mechanical Bridge

Function: A surgically implanted mechanical pump that draws blood from the left ventricle and pumps it into the aorta, unloading the LV and improving systemic perfusion.
Indications:
- Bridge-to-Transplant (BTT): For transplant-eligible patients awaiting a donor heart.
- Destination Therapy (DT): Permanent support for transplant-ineligible patients with end-stage HF (NYHA Class IV).
- Bridge-to-Recovery (BTR): Temporary support to allow native heart recovery.
Complications:
- Bleeding (esp. GI from acquired von Willebrand disease & AVMs).
- Thrombosis (pump, aortic root) & Stroke.
- Driveline infections.
- Right heart failure.

⭐ Clinical Pearl: Continuous flow from an LVAD often results in a non-palpable pulse. Blood pressure must be measured with a Doppler ultrasound to obtain a mean arterial pressure (MAP); the target is typically 65-85 mmHg.

Device Algorithm - The Big Picture

Eligibility: Symptomatic HFrEF (NYHA II-IV) on Guideline-Directed Medical Therapy (GDMT).
ICD (Primary Prevention): LVEF ≤ 35% + reasonable expectation of survival > 1 year.
CRT: Add for LVEF ≤ 35%, Sinus Rhythm, + LBBB with QRS ≥ 150 ms for maximal benefit.

⭐ The greatest mortality benefit from Cardiac Resynchronization Therapy (CRT) is observed in patients with a wide QRS complex (≥ 150 ms) and Left Bundle Branch Block (LBBB) morphology.

High‑Yield Points - ⚡ Biggest Takeaways

ICDs are primarily for preventing sudden cardiac death in HFrEF patients with an LVEF ≤35%; wait at least 40 days post-MI.

CRT is for symptomatic HFrEF (NYHA II-IV) with LVEF ≤35% and a wide QRS (≥150 ms, esp. LBBB) to improve symptoms and mortality.

CRT-D is a combination device used when criteria for both an ICD and CRT are met.

LVADs are used as a bridge-to-transplant or destination therapy for end-stage, refractory heart failure.

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