Week 3: Heart Failure

Question 1

What is heart failure?

Answer 1

Heart failure is the inability of the heart to pump enough blood to meet the body’s needs.

Question 2

What are the two major types of heart failure?

Answer 2

Left Heart Failure (LHF) = Systolic/“Congestive” heart failure.

Right Heart Failure (RHF) = Often due to lung disease.

Question 3

What causes left heart failure (LHF)?

Answer 3

Mostly caused by ischemic heart disease (e.g., coronary artery disease, heart attacks).

Question 4

What causes right heart failure (RHF)?

Answer 4

Lung diseases (COPD, pulmonary hypertension).

Left heart failure (LHF) → Blood backs up into the lungs.

Question 5

How is cardiac output (CO) calculated?

Answer 5

CO = Stroke Volume (SV) × Heart Rate (HR).

In heart failure, CO is reduced, leading to organ hypoxia.

Question 6

What is preload?

Answer 6

The amount of blood in the ventricles before contraction (end-diastolic volume).

Question 7

How does preload affect heart failure?

Answer 7

Too much preload overstretches the heart.

The Frank-Starling Law states that increased preload initially helps, but in heart failure, it worsens efficiency.

Question 8

What is afterload?

Answer 8

The resistance the heart must pump against (e.g., high blood pressure, valve disease).

Question 9

How does afterload contribute to left heart failure?

Answer 9

Increased afterload (e.g., from hypertension, aortic stenosis) → Left ventricular hypertrophy → Heart failure.

Question 10

What happens in left heart failure?

Answer 10

Weakened left ventricle → Reduced stroke volume → Low cardiac output.

Fluid backs up into the lungs → Pulmonary congestion & edema.

Question 11

What is the vicious cycle of left heart failure?

Answer 11

Low cardiac output → Reduced kidney perfusion.

Kidneys activate RAAS → Fluid retention → Increased preload.

More fluid retention → Worsened heart failure symptoms.

Question 12

What happens to the left ventricle in LHF?

Answer 12

It dilates and undergoes hypertrophy & fibrosis, making it less effective over time.

Question 13

What are symptoms of left heart failure?

Answer 13

Pulmonary congestion → Shortness of breath (dyspnea), crackles, pulmonary edema.

Difficulty breathing when lying flat (orthopnea).

Fatigue, confusion, cold extremities due to poor circulation.

Question 14

What happens in right heart failure?

Answer 14

Right ventricle fails to pump blood to the lungs.

Blood backs up into systemic veins, causing fluid retention & swelling.

Question 15

What are causes of right heart failure?

Answer 15

Left heart failure (most common cause).

Lung diseases (cor pulmonale) → Increased pulmonary resistance.

Tricuspid/pulmonic valve disease → Obstructed blood flow.

Question 16

What are symptoms of right heart failure?

Answer 16

Peripheral edema (swollen legs, ankles).

Jugular venous distension (JVD).

Hepatomegaly (enlarged liver) & ascites (fluid in the abdomen).

Fatigue & weight gain from fluid retention.

Question 17

How does the RAAS system worsen heart failure?

Answer 17

Causes Fluid retention & vasoconstriction.

This initially helps but worsens congestion over time.

Question 18

What role does the sympathetic nervous system (SNS) play in heart failure?

Answer 18

Increases heart rate & contractility to compensate for low output.

Long-term effect: Increases heart workload, worsening failure.

Question 19

How does ventricular hypertrophy affect heart failure?

Answer 19

Thickened heart muscle increases oxygen demand but reduces efficiency.

Question 20

What is the NYHA classification of heart failure? (Symptom-based)

Answer 20

Class I: No symptoms with normal activity.

Class II: Symptoms with exertion.

Class III: Symptoms with minimal activity.

Class IV: Symptoms at rest.

Question 21

What is the ACC/AHA staging system? (Structural-based)

Answer 21

Stage A: Risk factors present (e.g., hypertension, diabetes).

Stage B: Structural heart disease but no symptoms.

Stage C: Structural disease with symptoms.

Stage D: End-stage heart failure.

Question 22

How is heart failure diagnosed?

Answer 22

Clinical symptoms (dyspnea, fatigue, edema).

Physical exam (lung crackles, JVD, swelling).

Echocardiography (ECHO) to assess ejection fraction (EF).

Question 23

What is the normal vs. abnormal ejection fraction (EF)?

Answer 23

Normal EF: 55-70%.
Heart failure EF: <40% (systolic failure).

Question 24

What is the role of BNP in heart failure?

Answer 24

BNP (Brain Natriuretic Peptide) is elevated in heart failure due to ventricular wall stretch.

Question 25

What does a chest X-ray show in heart failure?

Answer 25

Pulmonary congestion (fluid in lungs).
Enlarged heart (cardiomegaly).

Question 26

What lifestyle changes help in heart failure?

Answer 26

Low sodium diet to reduce fluid retention.

Daily weight monitoring to track worsening edema.

Fluid restriction in severe cases.

Regular exercise (as tolerated).

Question 27

What medications are used to treat heart failure?

Answer 27

Diuretics – Reduce fluid overload (furosemide).

ACE Inhibitors / ARBs – Block RAAS (lisinopril, losartan).

Beta-Blockers – Reduce heart rate & oxygen demand (metoprolol, carvedilol).

Aldosterone Antagonists – Reduce sodium retention (spironolactone).

Digoxin – Increases contractility (only in severe cases).

Question 28

What advanced therapies are used in severe heart failure?

Answer 28

Pacemakers (ICD, CRT) – Help regulate heartbeats.

Left Ventricular Assist Devices (LVADs) – Mechanical pump for end-stage heart failure.

Heart Transplant – Last resort for patients with end-stage disease.