Definition of Congestive Heart Failure (CHF)
Congestive heart failure is a clinical syndrome characterized by typical symptoms (breathlessness, ankle swelling, and fatigue) and signs (elevated jugular venous pressure, pulmonary crackles, and peripheral edema) caused by a structural and/or functional cardiac abnormality, resulting in reduced cardiac output and/or elevated intracardiac pressures at rest or during stress. 1
Core Components of CHF Definition
Heart failure is a syndrome in which patients have symptoms of heart failure (typically shortness of breath at rest or during exertion, and/or fatigue) and signs of fluid retention (such as pulmonary congestion or ankle swelling), along with objective evidence of an abnormality of the structure or function of the heart at rest 1
The cardinal manifestations of heart failure are dyspnea and fatigue, which may limit exercise tolerance, and fluid retention, which may lead to pulmonary congestion and peripheral edema 1
Demonstration of an underlying cardiac cause is central to the diagnosis of heart failure, as the precise pathology determines specific treatment approaches 1
The term "heart failure" is preferred over the older term "congestive heart failure" because not all patients have volume overload at the time of initial or subsequent evaluation 1
Pathophysiological Basis
Heart failure results from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood 1
The syndrome can result from disorders of the pericardium, myocardium, endocardium, heart valves, great vessels, or abnormalities of heart rhythm and conduction 1
Common causes include coronary artery disease, hypertension, and dilated cardiomyopathy, with as many as 30% of dilated cardiomyopathy cases having a genetic cause 1
Heart failure involves complex compensatory mechanisms including neurohormonal activation and salt/water retention that initially help maintain cardiac output but eventually contribute to disease progression 2, 3
Classification Based on Ejection Fraction
Heart failure is classified based on left ventricular ejection fraction (LVEF) into three categories 1:
- Heart failure with reduced ejection fraction (HFrEF): LVEF <40%
- Heart failure with mid-range ejection fraction (HFmrEF): LVEF 40-49%
- Heart failure with preserved ejection fraction (HFpEF): LVEF ≥50%
Both systolic and diastolic dysfunction often coexist in heart failure patients, regardless of ejection fraction 1
Diastolic heart failure (often referred to as HFpEF) is more common in elderly patients and women, and is frequently associated with systolic hypertension and myocardial hypertrophy with fibrosis 1
Clinical Presentation
Typical symptoms include breathlessness, ankle swelling, and fatigue 1
Common signs include elevated jugular venous pressure, pulmonary crackles (rales), and peripheral edema 1, 4
Pulmonary rales are hallmark lung sounds in CHF and indicate pulmonary congestion requiring prompt treatment 4
Some patients may have exercise intolerance with little evidence of fluid retention, while others may present primarily with edema and minimal dyspnea 1, 4
Diagnostic Considerations
The diagnosis of heart failure is primarily clinical, based on a careful history and physical examination, supported by appropriate investigations 1
A clinical response to treatment directed at heart failure alone is not sufficient for diagnosis, though patients should generally show improvement in symptoms and signs with appropriate therapy 1
Heart failure should never be the only diagnosis - the underlying cause should always be identified 1
Asymptomatic structural or functional abnormalities of the heart are considered precursors of symptomatic heart failure and are associated with high mortality 1
Important Distinctions
Acute heart failure refers to rapid onset or worsening of symptoms and signs of heart failure, often requiring urgent treatment 1
Chronic heart failure is the persistent state, often punctuated by acute exacerbations 1
The terms "right heart failure" and "left heart failure" refer to syndromes presenting predominantly with congestion of the systemic or pulmonary veins, respectively, but do not necessarily indicate which ventricle is most severely damaged 1
By understanding this comprehensive definition of congestive heart failure, clinicians can better recognize, diagnose, and manage this complex syndrome that affects millions of patients worldwide.