Heart failure (HF) is a progressive syndrome resulting from abnormal cardiac structure or function impairing the ability of the ventricle to fill with or eject blood. Acute decompensated heart failure (ADHF) characterizes patients with worsening heart failure requiring hospitalization. Patients with persistent symptoms or refractory HF despite optimal oral therapies are classified as stage D via the American College of Cardiology/American Heart Association staging system. Additionally, ADHF patients have symptoms with minimal activity or at rest and are classified as New York Heart Association class III or IV.
Etiology and Pathophysiology
ADHF is characterized by a rapid decline in disease initiated from fluid retention and/or compromised cardiac function. Acute decompensation is frequently a consequence of disease progression or stems from medication or lifestyle noncompliance. Alternatively, ADHF may occur abruptly as a result of an acute insult (eg, atrial fibrillation, acute coronary syndrome).
The sympathetic nervous system (SNS) and renin-angiotensin-aldosterone system (RAAS) are activated from the initial etiology. The SNS and RAAS are beneficial in maintaining cardiac output and vital organ perfusion; however, they ultimately deteriorate cardiac function. The SNS increases systemic vascular resistance (SVR, afterload) causing pump dysfunction. The RAAS results in vasoconstriction and sodium and water retention leading to increased intravascular fluid volume (preload). Furthermore, arginine vasopressin is secreted causing vasoconstriction, free water retention, and hyponatremia.
B-type natriuretic peptide (BNP) is secreted from ventricular tissue in response to the fluid overload and ventricular wall stretch. The physiologic effect of BNP is to induce natriuresis as well as venous and arterial vasodilation. However, the release of endogenous BNP only mildly attenuates the negative compensatory neurohormonal cascade.
ADHF = acute decompensated heart failure
BP = blood pressure
BNP = brain natriuretic peptide
CO = cardiac output
CI = cardiac index
EF = ejection fraction
HF = heart failure
HR = heart rate
PAC= pulmonary artery catheter
PCWP = pulmonary capillary wedge pressure
RAAS = renin-angiotensin-aldosterone system
SNS = sympathetic nervous system
SVR = systemic vascular resistance
HF is a clinical diagnosis and no single test establishes its presence or absence. Nearly all patients with heart failure present with dyspnea. The absence of dyspnea makes heart failure highly unlikely and other explanations for the patient’s symptoms should be sought first.
BNP is a helpful biochemical marker in the diagnosis of ADHF. When used in conjunction with patient’s history and physical examination, BNP can be helpful in distinguishing ADHF from other conditions. A BNP concentration less than 100 pg/mL is highly predictive for the absence of ADHF. Unfortunately, BNP concentrations may be falsely elevated due to non-HF causes such as pneumonia or pulmonary embolism.
Placement of a pulmonary artery catheter (PAC), also known as a Swan-Ganz catheter) may be helpful in distinguishing the hemodynamic profile in ADHF. While hemodynamic parameters assist development ...