Curriculum

17 Sections
1548 Lessons
100 Days

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U01.01 Biochemistry
This biochemistry review for USMLE Step 1 covers essential topics including metabolism, enzymology, and molecular biology.
126
U01.02 Immunology
Prepare for USMLE Step 1 Immunology with a comprehensive review covering foundational concepts, immune system mechanisms, and key disorders to solidify your understanding and boost exam readiness.
42
U01.03 Microbiology
Review essential microbiology topics for the USMLE Step 1, covering key pathogens, mechanisms of disease, and antimicrobial principles critical for mastering infectious disease concepts.
172
U01.04 General Pathology
Explore key concepts in general pathology essential for the USMLE Step 1. This review covers fundamental principles, disease mechanisms, and clinical correlations to help you excel in your medical exam.
35
U01.05 Pharmacology
Master key pharmacology concepts for the USMLE Step 1 with a focus on drug mechanisms, therapeutic uses, adverse effects, and interactions essential for high-yield exam performance.
43
U01.06 Public Health Sciences
Review essential Public Health Sciences topics for the USMLE Step 1, covering epidemiology, biostatistics, health policy, and ethics to strengthen your understanding of foundational public health principles.
53
U01.07 Cardiovascular system
Comprehensive review of essential cardiovascular system topics to help you excel in the USMLE Step 1 exam, covering key concepts from anatomy to pathology.
73
U01.08 Endocrine system
Master essential concepts of the endocrine system for USMLE Step 1, covering hormone regulation, feedback mechanisms, and key disorders to boost your exam readiness.
51
U01.09 Gastrointestinal system
Review key topics in the gastrointestinal system for the USMLE Step 1, covering essential concepts in anatomy, physiology, pathology, and pharmacology to reinforce your understanding and test readiness.
131
U01.10 Hematology and Oncology
This review covers essential Hematology and Oncology topics for the USMLE Step 1, including hematopoiesis, coagulation, anemias, leukemias, lymphomas, and neoplastic syndromes.
148
U01.11 Musculoskeletal, Skin, and Connective Tissue
Review essential topics for the USMLE Step 1 Musculoskeletal, Skin, and Connective Tissue systems, covering anatomy, physiology, pathology, and pharmacology fundamentals critical for exam success.
178
U01.12 Neurology and Special Senses
Master the foundational concepts of Neurology and Special Senses with our USMLE Step 1 review, covering essential topics like neuroanatomy, neurophysiology, and sensory pathways.
143
U01.13 Psychiatry
Psychiatry for the USMLE Step 1 focuses on understanding the pathophysiology, diagnosis, and treatment of psychiatric disorders, with an emphasis on key concepts like neurotransmitter imbalances, mental health disorders, and pharmacology.
83
U01.14 Renal System
The Renal System review for USMLE Step 1 covers key concepts including renal physiology, nephron function, acid-base balance, electrolyte regulation, and renal pathology, crucial for understanding both normal and abnormal kidney functions.
81
U01.15 Reproductive System
The USMLE Step 1 Reproductive System review covers key concepts in human reproduction, including anatomy, physiology, endocrinology, and common pathologies affecting both male and female reproductive health.
124
U01.16 Respiratory System
The Respiratory System review for the USMLE Step 1 covers key concepts in anatomy, physiology, pathophysiology, and pharmacology essential for understanding respiratory diseases and treatments.
61
U01.17 Rapid Review
he USMLE Step 1 Rapid Review covers essential topics across multiple disciplines, providing a concise, high-yield overview to reinforce key concepts and optimize your exam preparation.
5

U01.07.046 Cardiomyopathies

Cardiomyopathies are diseases of the heart muscle, resulting in structural and functional abnormalities. The most common types of cardiomyopathy include dilated cardiomyopathy, hypertrophic obstructive cardiomyopathy, and restrictive/infiltrative cardiomyopathy. Understanding these conditions is essential for medical students preparing for the USMLE Step 1 exam.

1. Dilated Cardiomyopathy (DCM)

Overview:

Most common form of cardiomyopathy (90% of cases).
Often idiopathic or familial (e.g., mutations in the TTN gene, encoding the sarcomeric protein titin).

Etiologies:

Genetic: TTN gene mutations.
Drugs: Alcohol, cocaine, doxorubicin.
Infections: Coxsackie B virus, Chagas disease.
Ischemia: Coronary artery disease (CAD).
Systemic conditions: Hemochromatosis, sarcoidosis, thyrotoxicosis, wet beriberi.
Peripartum cardiomyopathy.

Clinical Findings:

Heart failure (HF).
S3 gallop.
Systolic regurgitant murmur.
Echocardiogram: Dilated heart.
Chest X-ray (CXR): Balloon appearance of the heart.

Treatment:

Treatment Option	Purpose
Sodium restriction	Reduce fluid retention
ACE inhibitors	Reduce afterload and improve EF
Beta-blockers (e.g., Metoprolol)	Improve symptoms and prevent arrhythmias
Diuretics	Reduce fluid overload
Mineralocorticoid receptor blockers (e.g., Spironolactone)	Prevent fibrosis and improve survival
Digoxin	Improve contractility in severe cases
Implantable cardioverter defibrillator (ICD)	Prevent sudden death from arrhythmias
Heart transplant	Consider for end-stage heart failure

Pathophysiology:

Leads to systolic dysfunction.
Eccentric hypertrophy: Sarcomeres added in series.
Can progress to heart failure.

Takotsubo Cardiomyopathy (Broken Heart Syndrome):

Caused by ventricular apical ballooning, likely due to increased sympathetic stimulation (e.g., stress).
Often seen after stressful events.

2. Hypertrophic Obstructive Cardiomyopathy (HOCM)

Overview:

60–70% of cases are familial, inherited as autosomal dominant.
Caused by mutations in genes encoding sarcomeric proteins (e.g., myosin binding protein C, β-myosin heavy chain).

Clinical Findings:

Syncope during exercise.
Sudden death in young athletes due to ventricular arrhythmia.
S4 gallop.
Systolic murmur: Due to left ventricular outflow tract obstruction.
Possible mitral regurgitation due to impaired mitral valve closure.

Treatment:

Treatment Option	Purpose
Cessation of high-intensity athletics	Prevent arrhythmias and sudden death
Beta-blockers (e.g., Metoprolol)	Improve symptoms and reduce arrhythmias
Non-dihydropyridine calcium channel blockers (e.g., Verapamil)	Improve diastolic filling and prevent arrhythmias
Implantable cardioverter defibrillator (ICD)	Prevent sudden death due to arrhythmias

Pathophysiology:

Diastolic dysfunction ensues.
Concentric hypertrophy (sarcomeres added in parallel), often with septal predominance.
Myofibrillar disarray and fibrosis are common.
Physiology of HOCM: Asymmetric septal hypertrophy and systolic anterior motion (SAM) of the mitral valve → outflow obstruction → dyspnea and possible syncope.

Other Causes of Concentric LV Hypertrophy:

Chronic hypertension.
Friedreich ataxia.

3. Restrictive/Infiltrative Cardiomyopathy

Overview:

Restrictive cardiomyopathies are characterized by impaired ventricular filling due to stiffened myocardium.

Etiologies:

Postradiation fibrosis.
Löffler endocarditis (associated with hypereosinophilic syndrome).
Endocardial fibroelastosis (thick fibroelastic tissue in young children).
Amyloidosis.
Sarcoidosis.
Hemochromatosis (though more commonly causes dilated cardiomyopathy).
Mnemonic: Puppy LEASH.

Clinical Findings:

Diastolic dysfunction.
Low-voltage ECG despite thick myocardium, especially in amyloidosis.
May see eosinophilic infiltrates in myocardium (in Löffler endocarditis).

Treatment:

Treatment Option	Purpose
Treatment of underlying cause (e.g., chelation for hemochromatosis)	Address the root cause
Diuretics	Manage symptoms of fluid overload
Heart transplant	For severe cases

Key Takeaways

Dilated Cardiomyopathy is the most common form and leads to systolic dysfunction.
Hypertrophic Obstructive Cardiomyopathy presents with diastolic dysfunction and can cause sudden death in young athletes.
Restrictive/Infiltrative Cardiomyopathy involves impaired diastolic filling, often with low-voltage ECG changes.

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USMLE Step 1 Review Series

Curriculum

U01.07.046 Cardiomyopathies

1. Dilated Cardiomyopathy (DCM)

Overview:

Etiologies:

Clinical Findings:

Treatment:

Pathophysiology:

Takotsubo Cardiomyopathy (Broken Heart Syndrome):

2. Hypertrophic Obstructive Cardiomyopathy (HOCM)

Overview:

Clinical Findings:

Treatment:

Pathophysiology:

Other Causes of Concentric LV Hypertrophy:

3. Restrictive/Infiltrative Cardiomyopathy

Overview:

Etiologies:

Clinical Findings:

Treatment:

Key Takeaways

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