Etiology → Mechanism → Failure Type
Myocardial infarction
- Loss of contractile myocardium
- Reduced contractility
- Systolic failure (reduced EF)
Hypertension
- Chronic pressure overload
- Concentric hypertrophy, stiff ventricle
- Diastolic failure (preserved EF)
Valvular disease
- Pressure or volume overload
- Stenosis → hypertrophy; regurgitation → dilation
- Stenosis → diastolic; regurgitation → systolic
Cardiomyopathy
- Primary myocardial disease
- Dilated → weak contraction; hypertrophic → impaired filling
- Dilated → systolic; hypertrophic → diastolic
Why the distinction is not academic
A patient with a reduced ejection fraction and a dilated ventricle has systolic failure; a patient with a normal ejection fraction, a thick-walled ventricle, and dyspnea on exertion has diastolic failure. The two require different management strategies, and the physical exam findings — displaced apex beat in systolic failure versus a sustained but non-displaced impulse in diastolic failure — reflect the underlying geometry. Recognizing the mechanism also predicts which complications are likely: systolic failure tends toward progressive dilation and arrhythmia, while diastolic failure tends toward pulmonary congestion with exertion.