Causes of Heart Failure

The causes of heart failure are dependent on the location of the abnormality.

In the conduction system of the heart:

• Tachycardia
• Bradycardia

In the valve system of the heart:

• Valvular stenosis
• Valvular insufficiency

Inadequate Preload:

• Blood loss
• Peripheral vasodilation
• Pericardial effusion
• Pulmonary artery hypertension

In the heart muscle:

• Weakened heart muscle (loss of contractility)
  • Dilated cardiomyopathy due to
    • Genetic mutations
    • Taurine deficiency
    • Tachycardia induced
    • Idiopathic
• Impaired distensibility/relaxation
  • Concentric hypertrophy
    • Hypertrophic cardiomyopathy
    • Systemic hypertension
  • Myocardial infiltration
    • Neoplasia
    • inflammation

Infection of the heart:

• Bacterial, viral, fungal, rickettsial, protozoal, heartworm

Shunting:

• Left-to-right: volume overload via the recirculation system
• Right-to-left: unoxygenated blood gains access to the systemic circulation