Several classification categories have been developed to classify heart failure.
These include, acute vs. chronic, left vs. right sided, high output vs. low output,
and systolic vs. diastolic heart failure. This chapter will focus more on the latter
classification which is the most commonly used because of its implication in the
treatment and long term outcome of heart failure patients.
Systolic heart failure (depressed ejection fraction)
This category describes the decrease in the heart muscle’s ability to
contract and pump blood against the systemic vascular resistance,
which usually is increased. Coronary artery disease (CAD) is the
predominant cause of heart failure in general and systolic dysfunction,
in particular, accounting for 60 to 75% of all cases in industrialized
countries. Both hypertension (high blood pressure) and diabetes
interact with a genetic predisposition augmenting the development of
CAD, as does dyslipidemia. Other etiologies include nonischemic
idiopathic cardiomyopathy, valvular heart disease, myocarditis, alcohol,
and drugs. Rheumatic fever remains a leading cause of heart failure in
Africa and Asia, particularly in the young population.
Diastolic heart failure (preserved ejection fraction)
In this category, the contractility of the cardiac muscle is intact or
increased, however, the relaxing phase of the cardiac cycle is impaired.