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Heart Failure


In a nutshell, heart failure is a condition in which the heart cannot pump enough blood to meet the body's needs.


Long-Term Therapy for Heart Failure


When the heart is not able to pump out the volume of blood it receives (backward failure) or cannot pump out enough blood to supply oxygen to the body (forward failure), the goal is to avoid or resolve a life-threatening crisis. Once the short-term disaster is resolved, we look to a more long-term therapy plan.
 
The Basics of Short-Term Heart Failureillustration of heart

In the short term, the body has an assortment of mechanisms to preserve circulation to the heart and brain and keep blood pressure up. The problem is that these mechanisms evolved for protection against blood pressure drop due to bleeding (as in predator attack). Protection against heart failure is an added benefit in the short term but in the long term problems arise.


So let’s say blood pressure drops. It could be because blood loss or more relevant to the topic of this discussion, it could be because the heart is not moving an adequate quantity of blood forward. Either way the tissues of the body need more blood supply and they need it quickly. What does the body do?


*Neurologic reflexes are activated that cause the heart to pump faster and stronger to move the maximum blood with each contraction.

*Antidiuretic hormone and aldosterone (an adrenal hormone) are released telling the kidney to hang on to every last sodium atom it sees. Where there is sodium, there is water and water (blood is mostly water) is the medium through which supplies reach our tissues and wastes are removed from our tissues. If we are going to have adequate blood, we need adequate water and that means hoard sodium.

*A hormone system called the renin-angiotensin system kicks on to produce a material called Angiotensin II. Angiotensin II is one of the strongest vasoconstrictors known to science. It closes off vessels supplying non-essential areas preserving circulation for the heart and brain, which must be kept perfused at all costs.


So, in short, our heart works harder, our vessels close off, and we retain salt. This is all wonderful but if the heart is weak, it cannot handle the extra blood volume brought on by retaining salt, nor can it push blood through constricted vessels or continue pumping faster and harder all the time.

 

Long-Term Heart Failure Management

Managing the failing heart is all about creating a balance for what a sick heart can handle and lifting the burden created by the protective mechanisms of the crisis. Our patient should be comfortable and able to perform modest exercise. We want to minimize discomfort due to coughing, fluid build-up, or collapse.

Diuretics
A diuretic is a drug that increases urine production. Diuretics are life-saving in a heart failure crisis where the lungs are filling with fluid because the heart cannot pump blood in quantities large enough to prevent fluid build-up. The dose needed for long term comfort is highly individual and may change depending on the stage of disease. Furosemide is almost always the first diuretic used as it is one of the most powerful. It is often used in combination with an ACE inhibitor for long term therapy.