Overview
Introduction
Heart failure develops when the heart is unable to maintain adequate cardiac output or when it maintains output only by increasing filling pressures.
Heart failure develops when the heart is unable to maintain adequate cardiac output or when it maintains output only by increasing filling pressures. The heart may be weak, stiff, overloaded, damaged by ischemia, affected by valve disease, or disrupted by abnormal rhythm. When cardiac output falls, the body tries to compensate. These compensatory responses include: * Sympathetic nervous system activation * Increased heart rate * Vasoconstriction * Renin-angiotensin-aldosterone system activation * Sodium and water retention * Increased blood volume * Increased preload and afterload * Increased myocardial workload At first, compensation may help maintain blood pressure and perfusion. Over time, these same responses worsen congestion, increase cardiac strain, and contribute to progressive heart failure. Simple explanation for learners: The heart is not moving blood forward effectively. The kidneys sense reduced perfusion and hold onto salt and water. The extra fluid increases the workload on the heart and backs up into the lungs, legs, abdomen, or both. For REx-PN (Canada), items rarely announce the topic in the first sentence. Anchor to objective data, trajectory, and the safest next step for the...
