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Introduction
1. Anatomy
2. Microbiology
3. Physiology
4. Pathology
4.1 General pathology
4.2 Central and peripheral nervous system
4.3 Cardiovascular system
4.3.1 Endocarditis, myocarditis and pericarditis
4.3.2 Cardiomyopathies
4.3.3 Hypertrophy of the heart
4.3.4 Atherosclerosis and arteriosclerosis
4.3.5 Ischemic heart disease (IHD)
4.3.6 Diagnosis of AMI/ ACS
4.3.7 Heart failure
4.3.8 Valvular heart disease
4.3.9 Arrhythmias
4.3.10 Vascular disorders
4.3.11 Common types of emboli
4.3.12 Vasculitis
4.3.13 Diseases of the veins
4.3.14 Additional information
4.4 Respiratory system
4.5 Hematology and oncology
4.6 Gastrointestinal pathology
4.7 Renal, endocrine and reproductive system
4.8 Musculoskeletal system
5. Pharmacology
6. Immunology
7. Biochemistry
8. Cell and molecular biology
9. Biostatistics and epidemiology
10. Genetics
11. Behavioral science
Wrapping up
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4.3.7 Heart failure
Achievable USMLE/1
4. Pathology
4.3. Cardiovascular system

Heart failure

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Heart failure (cardiac failure) is the inability of the heart to maintain an adequate cardiac output to meet the body’s metabolic needs. It can be:

  • Systolic or diastolic
  • Left ventricular, right ventricular, or biventricular
  • Acute or chronic

Systolic failure is failure of the ventricle’s normal pumping ability. It presents with a reduced ejection fraction (EF) (<40%).

Diastolic dysfunction is impaired ventricular relaxation or filling due to increased wall stiffness. EF is preserved in diastolic dysfunction, but filling pressures are increased.

Congestive heart failure is heart failure with pulmonary and/or systemic congestion. It can occur in LHF, RHF, or biventricular failure.

Cardiac failure
Cardiac failure

Common causes of heart failure

  • CAD or IHD
  • DM
  • Hypertension
  • Cardiomyopathy
  • Myocarditis
  • Congenital heart disease
  • Valvular heart disease
  • Arrhythmias esp. tachyarrhythmias
  • Alcohol abuse, Beriberi
  • HIV/AIDS
  • Hypervitaminosis E
  • Radiation or chemotherapy
  • Thyroid disorders
  • Severe anemia
  • Cocaine and drug abuse
  • AV shunts
  • Massive pulmonary embolism
  • Cardiac tamponade and constrictive pericarditis

I) Left-sided heart failure (LHF):

LHF results from left ventricular (LV) dysfunction.

  • Systolic dysfunction of the LV is due to impaired ventricular contractility. Causes include AMI, CAD, volume overload from MR or AR, and dilated cardiomyopathy.
  • Systolic dysfunction can also result from increased afterload, such as systemic hypertension or aortic stenosis.
  • Diastolic dysfunction of the LV is due to impaired relaxation (for example, from LVH, HOCM, restrictive cardiomyopathy, or CAD) or impaired ventricular filling (for example, from MS, cardiac tamponade, or constrictive pericarditis).

LHF causes fluid accumulation in the lungs (pulmonary edema) and systemic hypoperfusion.

II) Right-sided heart failure (RHF):

RHF results from right ventricular (RV) dysfunction.

  • Systolic dysfunction of the RV may result from increased afterload due to pulmonary HT, COPD, PE, ILD, ARDS, or pulmonic stenosis.
  • Impaired RV contractility can also result from AMI, volume overload from TR or PR, and dilated cardiomyopathy.
  • Diastolic dysfunction of the RV can result from tricuspid stenosis, plus pathologies similar to those causing diastolic dysfunction of the LV (such as tamponade).

The most common cause of RV failure is LV failure. RHF causes fluid buildup in the systemic and portal venous system, presenting as peripheral pitting edema and hepatic congestion.

Comparison between LHF and RHF

LHF
  • Dyspnea, orthopnea, paroxysmal nocturnal dyspnea
  • Cough with frothy sputum
  • Decreased urine output
  • Pulmonary crackles, rhonchi
  • In severe cases, loud P2, systolic murmur from MR, pulsus alternans
  • Hemosiderin containing alveolar macrophages or “heart failure” cells
  • CxR shows Kerley’s B lines on from septal pulmonary edema; perihilar congestion and alveolar infiltrates
RHF
  • Peripheral pitting edema, ascitis
  • Hepatosplenomegaly
  • Raised JVP
  • In severe cases, Kussmaul sign, TR murmur and right ventricular heave
  • Hepatojugular reflex will be positive
  • Central cyanosis more common
Raised JVP
Raised JVP

S3 and S4 can be auscultated.

  • S3 is due to abnormal filling of blood into an already volume-overloaded ventricle.
  • S4 is due to forceful atrial contraction against a stiff ventricle and is seen in diastolic dysfunction such as LVH or RVH.

Types and Definitions of Heart Failure

  • Inability of heart to maintain adequate cardiac output
  • Classified as systolic vs. diastolic, left vs. right vs. biventricular, acute vs. chronic
  • Congestive heart failure: heart failure with pulmonary/systemic congestion

Systolic vs. Diastolic Dysfunction

  • Systolic: reduced ejection fraction (<40%), impaired ventricular contraction
  • Diastolic: preserved ejection fraction, impaired relaxation/filling, increased filling pressures

Common Causes of Heart Failure

  • CAD/IHD, hypertension, DM, cardiomyopathy, myocarditis
  • Valvular/congenital heart disease, arrhythmias, alcohol/drug abuse
  • Thyroid disorders, severe anemia, AV shunts, PE, cardiac tamponade, constrictive pericarditis

Left-Sided Heart Failure (LHF)

  • LV systolic dysfunction: impaired contractility (AMI, CAD, MR, AR, dilated cardiomyopathy)
  • LV diastolic dysfunction: impaired relaxation/filling (LVH, HOCM, restrictive cardiomyopathy, MS, tamponade)
  • Results: pulmonary edema, systemic hypoperfusion

Right-Sided Heart Failure (RHF)

  • RV systolic dysfunction: increased afterload (pulmonary HT, COPD, PE, ILD, ARDS, pulmonic stenosis), impaired contractility (AMI, TR, PR, dilated cardiomyopathy)
  • RV diastolic dysfunction: tricuspid stenosis, tamponade
  • Most common cause: LV failure
  • Results: systemic/portal congestion (peripheral edema, hepatic congestion)

Clinical Features: LHF vs. RHF

  • LHF:

    • Dyspnea, orthopnea, paroxysmal nocturnal dyspnea
    • Cough with frothy sputum, decreased urine output
    • Pulmonary crackles, rhonchi, loud P2, systolic murmur (MR), pulsus alternans
    • Heart failure cells (hemosiderin-laden macrophages)
    • CXR: Kerley B lines, perihilar congestion, alveolar infiltrates

  • RHF:

    • Peripheral pitting edema, ascites, hepatosplenomegaly
    • Raised JVP, Kussmaul sign, TR murmur, RV heave
    • Positive hepatojugular reflex, central cyanosis

Heart Sounds in Heart Failure

  • S3: abnormal filling into volume-overloaded ventricle
  • S4: forceful atrial contraction against stiff ventricle (seen in LVH/RVH, diastolic dysfunction)

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Heart failure

Heart failure (cardiac failure) is the inability of the heart to maintain an adequate cardiac output to meet the body’s metabolic needs. It can be:

  • Systolic or diastolic
  • Left ventricular, right ventricular, or biventricular
  • Acute or chronic

Systolic failure is failure of the ventricle’s normal pumping ability. It presents with a reduced ejection fraction (EF) (<40%).

Diastolic dysfunction is impaired ventricular relaxation or filling due to increased wall stiffness. EF is preserved in diastolic dysfunction, but filling pressures are increased.

Congestive heart failure is heart failure with pulmonary and/or systemic congestion. It can occur in LHF, RHF, or biventricular failure.

Common causes of heart failure

  • CAD or IHD
  • DM
  • Hypertension
  • Cardiomyopathy
  • Myocarditis
  • Congenital heart disease
  • Valvular heart disease
  • Arrhythmias esp. tachyarrhythmias
  • Alcohol abuse, Beriberi
  • HIV/AIDS
  • Hypervitaminosis E
  • Radiation or chemotherapy
  • Thyroid disorders
  • Severe anemia
  • Cocaine and drug abuse
  • AV shunts
  • Massive pulmonary embolism
  • Cardiac tamponade and constrictive pericarditis

I) Left-sided heart failure (LHF):

LHF results from left ventricular (LV) dysfunction.

  • Systolic dysfunction of the LV is due to impaired ventricular contractility. Causes include AMI, CAD, volume overload from MR or AR, and dilated cardiomyopathy.
  • Systolic dysfunction can also result from increased afterload, such as systemic hypertension or aortic stenosis.
  • Diastolic dysfunction of the LV is due to impaired relaxation (for example, from LVH, HOCM, restrictive cardiomyopathy, or CAD) or impaired ventricular filling (for example, from MS, cardiac tamponade, or constrictive pericarditis).

LHF causes fluid accumulation in the lungs (pulmonary edema) and systemic hypoperfusion.

II) Right-sided heart failure (RHF):

RHF results from right ventricular (RV) dysfunction.

  • Systolic dysfunction of the RV may result from increased afterload due to pulmonary HT, COPD, PE, ILD, ARDS, or pulmonic stenosis.
  • Impaired RV contractility can also result from AMI, volume overload from TR or PR, and dilated cardiomyopathy.
  • Diastolic dysfunction of the RV can result from tricuspid stenosis, plus pathologies similar to those causing diastolic dysfunction of the LV (such as tamponade).

The most common cause of RV failure is LV failure. RHF causes fluid buildup in the systemic and portal venous system, presenting as peripheral pitting edema and hepatic congestion.

Comparison between LHF and RHF

LHF
  • Dyspnea, orthopnea, paroxysmal nocturnal dyspnea
  • Cough with frothy sputum
  • Decreased urine output
  • Pulmonary crackles, rhonchi
  • In severe cases, loud P2, systolic murmur from MR, pulsus alternans
  • Hemosiderin containing alveolar macrophages or “heart failure” cells
  • CxR shows Kerley’s B lines on from septal pulmonary edema; perihilar congestion and alveolar infiltrates
RHF
  • Peripheral pitting edema, ascitis
  • Hepatosplenomegaly
  • Raised JVP
  • In severe cases, Kussmaul sign, TR murmur and right ventricular heave
  • Hepatojugular reflex will be positive
  • Central cyanosis more common

S3 and S4 can be auscultated.

  • S3 is due to abnormal filling of blood into an already volume-overloaded ventricle.
  • S4 is due to forceful atrial contraction against a stiff ventricle and is seen in diastolic dysfunction such as LVH or RVH.
Key points

Types and Definitions of Heart Failure

  • Inability of heart to maintain adequate cardiac output
  • Classified as systolic vs. diastolic, left vs. right vs. biventricular, acute vs. chronic
  • Congestive heart failure: heart failure with pulmonary/systemic congestion

Systolic vs. Diastolic Dysfunction

  • Systolic: reduced ejection fraction (<40%), impaired ventricular contraction
  • Diastolic: preserved ejection fraction, impaired relaxation/filling, increased filling pressures

Common Causes of Heart Failure

  • CAD/IHD, hypertension, DM, cardiomyopathy, myocarditis
  • Valvular/congenital heart disease, arrhythmias, alcohol/drug abuse
  • Thyroid disorders, severe anemia, AV shunts, PE, cardiac tamponade, constrictive pericarditis

Left-Sided Heart Failure (LHF)

  • LV systolic dysfunction: impaired contractility (AMI, CAD, MR, AR, dilated cardiomyopathy)
  • LV diastolic dysfunction: impaired relaxation/filling (LVH, HOCM, restrictive cardiomyopathy, MS, tamponade)
  • Results: pulmonary edema, systemic hypoperfusion

Right-Sided Heart Failure (RHF)

  • RV systolic dysfunction: increased afterload (pulmonary HT, COPD, PE, ILD, ARDS, pulmonic stenosis), impaired contractility (AMI, TR, PR, dilated cardiomyopathy)
  • RV diastolic dysfunction: tricuspid stenosis, tamponade
  • Most common cause: LV failure
  • Results: systemic/portal congestion (peripheral edema, hepatic congestion)

Clinical Features: LHF vs. RHF

  • LHF:

    • Dyspnea, orthopnea, paroxysmal nocturnal dyspnea
    • Cough with frothy sputum, decreased urine output
    • Pulmonary crackles, rhonchi, loud P2, systolic murmur (MR), pulsus alternans
    • Heart failure cells (hemosiderin-laden macrophages)
    • CXR: Kerley B lines, perihilar congestion, alveolar infiltrates

  • RHF:

    • Peripheral pitting edema, ascites, hepatosplenomegaly
    • Raised JVP, Kussmaul sign, TR murmur, RV heave
    • Positive hepatojugular reflex, central cyanosis

Heart Sounds in Heart Failure

  • S3: abnormal filling into volume-overloaded ventricle
  • S4: forceful atrial contraction against stiff ventricle (seen in LVH/RVH, diastolic dysfunction)