Etiology of Heart Failure

Introduction

Heart failure (HF) is a complex clinical syndrome that results from structural or functional impairment of ventricular filling or the ability to eject blood. The underlying causes of HF are diverse and can be classified into several broad categories.

Main Causes of Heart Failure

1. Ischemic Heart Disease (Coronary Artery Disease, CAD)

• The most common cause of HF globally.
• Results from reduced blood supply to the heart muscle due to coronary artery narrowing or occlusion.
• Can lead to myocardial infarction (heart attack), which damages the heart muscle and reduces its pumping ability.

2. Hypertension (High Blood Pressure)

• Chronic high blood pressure forces the heart to work harder, leading to left ventricular hypertrophy (thickening of the heart muscle).
• Over time, this causes the heart to weaken and become inefficient.

3. Valvular Heart Diseases

• Conditions like aortic stenosis, mitral regurgitation, and other valve disorders increase the heart's workload.
• Over time, improper valve function can lead to HF.

4. Cardiomyopathies

• Dilated Cardiomyopathy (DCM): The heart's chambers enlarge and weaken, reducing pumping efficiency.
• Hypertrophic Cardiomyopathy (HCM): The heart muscle thickens abnormally, making it harder for the heart to pump blood.
• Restrictive Cardiomyopathy (RCM): The heart muscle becomes stiff, restricting filling.
• Often idiopathic but can be linked to genetic factors, infections, or toxic exposure (e.g., alcohol, chemotherapy).

5. Arrhythmias

• Chronic or recurrent atrial fibrillation can weaken the heart and lead to HF.
• Ventricular arrhythmias can lead to sudden cardiac dysfunction.

6. Myocarditis

• Inflammation of the heart muscle, often caused by viral infections (e.g., Coxsackievirus, COVID-19), bacterial infections, or autoimmune diseases.
• Can lead to dilated cardiomyopathy and HF.

7. Congenital Heart Diseases

• Structural defects present from birth (e.g., ventricular septal defect, Tetralogy of Fallot) can cause HF if untreated.

8. Endocrine Disorders

• Diabetes mellitus: Increases the risk of HF due to vascular damage and metabolic dysfunction.
• Thyroid disorders: Hyperthyroidism (increased metabolism) or hypothyroidism (decreased metabolism) can cause heart dysfunction.
• Pheochromocytoma: Excessive catecholamine release leads to severe hypertensive stress on the heart.

9. Toxic and Drug-Induced Causes

• Chronic alcohol abuse can lead to alcoholic cardiomyopathy.
• Certain chemotherapy drugs (e.g., doxorubicin) are cardiotoxic.
• Cocaine and other stimulants can cause acute or chronic myocardial injury.

10. Pulmonary Causes (Right-Sided HF)

• Pulmonary Hypertension: Increased pressure in the pulmonary arteries leads to right heart failure.
• Chronic obstructive pulmonary disease (COPD) and sleep apnea contribute to heart strain.

11. Systemic Diseases

• Amyloidosis: The buildup of abnormal proteins in the heart leads to restrictive cardiomyopathy.
• Sarcoidosis: An inflammatory disease that can cause myocardial infiltration and HF.
• Hemochromatosis: Excess iron deposits in the heart leading to dysfunction.

Conclusion

Heart failure has many potential causes, and identifying the underlying etiology is crucial for effective treatment. Managing risk factors like hypertension, diabetes, and obesity can significantly reduce the risk of developing HF.

References

For more detailed recommendations on heart failure etiology, please refer to:

• American Heart Association Guidelines
• European Society of Cardiology Guidelines

Source recommendations

1. American Heart Association Guidelines

1. https://professional.heart.org/en/guidelines-and-statements
2. https://www.heart.org/
3. https://professional.heart.org/en/guidelines-statements
4. https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines
5. https://www.heart.org/en/healthy-living/fitness/fitness-basics/aha-recs-for-physical-activity-in-adults

2. European Society of Cardiology Guidelines

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines
2. https://academic.oup.com/eurheartj/article/42/34/3227/6358713
3. https://www.escardio.org/Guidelines
4. https://academic.oup.com/eurheartj/article/44/39/4043/7238227
5. https://www.escardio.org/