Congestive Heart Failure
Congestive heart failure is the end result of the heart’s inability to pump blood effectively that can lead to significant multi-system organ dysfunction, or death. Pumping blood to vital organs, such as the brain, liver and kidneys, as well as to the heart itself, is the singular function of the heart muscle, which works in tandem with the lungs, whose primary critical function is to oxygenate the blood. If the heart is prevented from pumping our “life blood” effectively, a two-fold problem develops that can lead to a cascade of life threatening events: A reduction in blood supply to the vital organs; and a backup of fluid into the lungs, leading to a reduction in the ability of the lungs to oxygenate the blood, – a phenomena known as pulmonary edema.
Heart pump dysfunction can have many causes, although it is generally a function of inadequate blood flow to the heart related to an acute myocardial infarction (heart attack) which causes a blockage in the arteries supplying blood to the heart, or to a narrowing of the coronary arteries that supply blood to the heart, which results in a progressive reduction in cardiac blood flow, as the diameter of the coronary artery is decreased. Additional causes of congestive heart failure include heart muscle weakness (cardiomyopathy), viral infections or toxins,-including prolonged alcohol exposure, and heart valve disease, as well as hypertension (high blood pressure), cardiac arrhythmia (irregular heart beat) , and diabetes.
The effect of any of these causes, or a combination of more than one, is a reduction of pump function that decreases cardiac output and will ultimately result in a failure of the vital organs, including the heart. The compromised blood flow leads to a progressive loss of function of the organs, and a subsequent inability of the patient to function normally. The reduction in cardiac output also leads to increased pressures in the pulmonary arteries leading to the lungs, which causes a leakage of fluid into the alveoli (air sacs). The congested lungs (pulmonary edema) become increasingly unable to oxygenate the blood, and a vicious cycle is set up such that the reduction in pump function leads to a reduction in coronary artery blood flow, which further reduces pump function as the heart pumps a reduced supply of blood and oxygen back to itself.
The other vital organs, already compromised by a reduction of blood flow, continue to deteriorate as the oxygen supply is more and more depleted. If this cycle is not reversed, the continual reduction in pump function will ultimately be fatal, as the heart ceases to pump and total organ dysfunction occurs.
© April 2015. James F. Lineback, MD, FCCP. All rights reserved.