Section I. CONGESTIVE HEART FAILURE AND ITS TREATMENT
Heart disease is the number one killer in the United States today. Two people
succumb to conditions related to heart disease every minute of the day. However, it
must be remembered that heart disease can be treated. Discoveries of new ways to
use existing drugs and improved surgical techniques translate into longer and more
productive lives for persons who have heart disease. In lesson 2 of this subcourse,
various disease states that can affect the circulatory system were discussed. In this
lesson, some of these conditions will be reviewed. The primary focus of this lesson will
be the drug used to treat these conditions.
3-2. REVIEW OF CONGESTIVE HEART FAILURE
Congestive heart failure may be defined as nonefficient pumping of the heart.
This inefficiency in pumping the heart leads to an increase in the size of the heart and
an increase in the heart rate. This increase in heart size and heart rate result because
of the heart's attempt to compensate for the poor efficiency in pumping blood to other
parts of the body. Consequently, the kidneys improperly function. Improperly
functioning kidneys result in edema of the extremities due to improper excretion
(removal) of sodium and waste products in the urine. If a patient's congestive heart
failure becomes acute, he may have pulmonary edema due to poor kidney function.
3-3. TREATMENT OF CONGESTIVE HEART FAILURE
Rest and restriction of sodium (that is, sodium chloride) intake are important
aspects of the non-pharmacologic treatment of congestive heart failure. Drug treatment
includes ACE Inhibitors, diuretics (see Lesson 8), digitalis and the related cardiac
glycosides, beta adrenergic blockers, and spironolactone.
3-4. ANGIOTENSIN-CONVERTING ENZYME INHIBITORS (ACE INHIBITORS)
a. Angiotensin-converting enzyme inhibitors (ACE inhibitors) belong to a unique
class of vasodilators. ACE inhibitors block a specific enzyme (angiotensin converting
enzyme) that converts angiotensin I to angiotensin II. Angiotensin II is one of the most
potent vasodilators in the body. The mechanism of action of ACE inhibitors in the
treatment of congestive heart failure relies on the ability to cause both arterial and
venous vasodilation through this inhibition, thereby decreasing the workload on the
heart. Hemodynamic effects associated with long term use include increased cardiac
function and decreased blood pressure and heart rate. Significant improvements are