Samuel E. Greenberg, M.D.
Congestive Heart Failure (CHF) is a condition, not a disease. It is a constellation of signs and symptoms, caused by a multitude of diseases, not all of which, primarily involve the heart muscle. This explains why most states, in particular, preclude the use of heart failure, as well as respiratory and cardiac arrest as a cause of death, on the Death Certificate. These are all modes of dying, not causes of death.
Congestive Heart Failure (CHF) is exactly what it's name implies-failure of the heart muscle to keep the lung from becoming congested. This congestion occurs when fluid leaks out of the blood vessels into the air sacs and displaces the air. When the pressure in the blood vessels is elevated by the heart muscle's inability to propel the blood forward, out of the lungs into the rest of the body, fluid leaks out of the blood stream, through micro permeable vessel walls into the air sacs (alveoli). This manifests itself, clinically, as Congestive Heart Failure.
So any inability of the heart muscle to pump the blood out of the lungs, whether from a weakening of the muscle or by an overburdening of the heart muscle can result in CHF.
Weakening of the heart muscle, most commonly, in Western Societies comes from Coronary Artery disease, whereby cholesterol plaques build up in the lining of the blood vessels. This build up of cholesterol plaques results in obstruction of blood flow and death of a portion of the heart muscle. Other causes of heart muscle injury vary from viral infections of the muscle (called myocarditis), to toxins such as alcohol, to disease states, such as hypertension, kidney or liver failure.
Over-burdening of the heart muscle, on the other hand, occurs in hypermetabolic states such as hyperthyroidism, vitamin deficiency (Beri Beri), severe anemias, and cardiac valvular defects, such as Aortic Stenosis or Mitral Regurgitation.
Signs and Symptoms
The signs and symptoms of CHF include, getting tired easily, weakness, confusion, shortness of breath (initially with exercise, but, as the CHF worsens, at rest and associated with the inability to lie or sleep lying flat in bed. This necessitates sleeping with 2 or more pillows called 2 pillow Orthopnea), a persistent cough from congested lungs, swelling of the feet and abdomen, from fluid accumulation as the heart muscle weakens, along with darkening of the finger and toenails (cyanosis), from oxygen poor blood perfusing the extremities at a slower rate of flow.
Physically, fluid in the air sacs can be heard with a stethoscope, as well as the addition of one or two additional heart sounds. Instead of just the lub-dub, lub-dub of the 1st. and 2nd. heart sounds, a 3rd. and 4th. heart sound are added, either da-lub-dub or lub-dub-da (Ken-tuc-ky or Ten-ne-see). The pulse may even vary in intensity on alternate beats (pulsus alternans). There is, of course, a faster pulse at rest and with exercise, as the heart tries to mitigate its weakness, by increasing its rate. The patient will often complain of the heart feeling as if he had run around the block, when all he did is cross the room. Prominent engorged veins, from blood backup, is noticeable as prominent neck and abdominal wall veins and a large palpable swollen liver is detected. Swollen feet and ankles, initially occurring after prolonged sitting or standing and disappearing overnight, but later persisting all the time, becomes evident.
Congestive Heart Failure is divided into many categories:
I.) Acute and Chronic CHF
A.) Acute CHF- As the name implies; when the heart muscle suddenly becomes too weak to propel the blood forward, sudden CHF ensues. This is usually heralded by the abrupt onset of Shortness Of Breath.
The classic example of this occurrence is from the onset of a fairly extensive heart attack (myocardial infarction). This occurs from Coronary Atherosclerotic Artery disease. With so much muscle damage at one time, the remaining muscle cannot compensate and CHF develops. Occasionally, the patient will present to the Emergency Room in acute CHF from a myocardial infarction, but without a history of chest discomfort (Silent myocardial infarction). Therefore it is incumbent upon the physician to suspect and to check for a myocardial infarction in all and any cases of acute CHF, even if there is no antecedent pain. This is the standard of care, since, if detected early enough, possibly something can be done to save the heart muscle and reverse some or all of the damage.
Other causes of Acute CHF are: 1.) Arrhythmias, such as a very fast or very slow heart rate; 2.) Rhythm irregularities between the upper and lower chambers of the heart as in Heart blocks; 3.) Sepsis; 4.) Pulmonary Emboli; 5.) Acute stroke; 6.) Viral infections.
B.) Chronic CHF- This is, most often, an insidious condition, occurring slowly over a period of months or years. In this condition, shortness of breath on exertion is often the only first symptom. Sometimes the feet will swell during the afternoon and go down at night, assisted by frequent nocturnal trips to urinate this excessive fluid. As the weakened heart muscle , which is too weak during the active daytime, is able to mobilize the fluid from the subcutaneous tissues during a horizontal and restful night, the kidneys are presented with more blood and, therefore, more urine is produced. Later, sleeping with 2 pillow Orthopnea becomes necessary.
Causes of Chronic CHF are of a more chronic duration, but can occur from some of the same causes as with Acute CHF. 1.) Repetitive small myocardial infarctions; 2.) hypertension; 3.) valvular defects; 4.) slow renal deterioration 5.) multiple recurrent small pulmonary emboli; 6.) and diseases that infiltrate the heart muscle.
II. Compensated and Decompensated CHF
Compensated CHF simply refers to the chronic form of CHF that is under control with medication. Whereas, if symptoms are frequent, such as nocturnal shortness of breath, which goes away in the morning or when sitting up and moving around, with or without treatment, the condition is referred to as Decompensated.
III. Systolic and Diastolic CHF
If the heart muscle is too weak to push the blood in the ventricular chambers forward, but still fill up with the usual quantity of blood, as they do in the healthy state, and do so without creating a greatly increased pressure in those chambers, then Systolic CHF is present. In other words, even though the muscle is too weak to propel enough blood forward, the muscle can still dilate to comfortably handle the incoming blood without stress on the chamber walls and, therefore, without an increase in the pressure inside those chambers.
If, as in Hypertensive Heart Disease, the chambers hold less blood, in part because the wall is thickened from having to push against increased resistance, i.e., high Blood Pressure, then the chamber wall muscles are not as elastic, do not have the give to dilate as much and the pressure builds up, such that, even less blood can be pushed into that chamber from the upper chambers (Atria). Then Diastolic CHF is present, because less blood can enter the lower chambers (Ventricles) and must, perforce, back up into the lungs, causing CHF.
IV. Right and Left CHF
The heart is divided into 2 lower chambers (Ventricles). The Right Ventricle sends blood to the lung. The Left Ventricle sends blood out of the heart to the rest of the body. Failure of the Right Ventricle, before the blood reaches the lungs, results in the backup of blood in the venous return system of the body, resulting in distended veins, a swollen liver, occasionally with fluid in the abdominal cavity (ascites) and with swollen legs. Failure of the Left Ventricle, after the blood has gone through the lungs results in the classical symptoms of shortness of breath, cyanosis, etc., because of inability to propel the oxygenated blood forward to the distal tissues. If Left sided CHF lasts long enough, it will result in Rt. sided CHF also developing. Because the Kidney puts out hormones which regulate salt and fluid retention, when it does not receive enough blood, as in Lt . sided heart failure, it will hold salt and fluid in the body hoping to increase the fluid volume, since it interprets this lack of blood and oxygen as one of an anemic state. If the liver becomes engorged with backed up blood, as in Rt. sided CHF, it will not destroy these kidney hormones in it's usual efficient manner and they will accumulate, holding more salt and water in the body.
V.) High and Low Output CHF
Low Output CHF results from a weakened heart muscle and is commensurate with the classical sign and symptoms of CHF. High Output CHF occurs in the overburdening types of CHF, such as Beri Beri, or Hyperthyroidism or severe Anemia, where the heart is in a feverish state of activity, having to move the blood around vigorously, and wearing itself out.
Treatment of CHF
Since CHF occurs from the presence of excessive fluid in the air sacs due to an absolute or relative weakened heart muscle, the solution is directed at these two problems. Of course, once the patient is comfortable, then the underlying disease should be sought for and addressed, such as treating the Hyperthyroidism, or balloon dilating and stenting the Coronary Arteries, or giving blood, etc.
So, first we try and remove the fluid from the lungs so the patient can breath.
Then, we try and increase the strength of the heart muscle if possible, or, at least, relieve the burden on the heart muscle.
Relieve the lungs of fluid - By simply dehydrating the blood stream with the use of Diuretics, leaving less free fluid to be available to infiltrate the tissues, leak into the air sacs or for the heart muscle to have to move around, in it's weakened state.
Strengthen the heart muscle - Unfortunately, this is our biggest problem. We have very few medications which can be absorbed orally and not be destroyed by the stomach juices, which will strengthen the heart muscle.
A.) Digitalis - This drug has been in use for a century and is still very useful in treating CHF. It has been shown to improve the stamina and life style of CHF patients, but, for some unknown reason, not prolong life. At present, this is the only oral heart muscle strengthening muscle (IONOTROPIC AGENT) available.
B.) Other Ionotropic Agents - Intravenously, we do have some very good agents, but, of course, the route of administration is cumbersome and expensive. Dobutamine and Dopamine are examines of this genre. On the horizon, however, there are plenty of candidates, which should be available shortly, some of which can be taken orally. What about a patch?
3.) Decrease the burden against which the heart muscle must push against. (Peripheral Vascular Dilators).
A.) ACE Inhibitors - Stands for Angiotensin Converting Enzyme Inhibitors. These ACE Inhibitors are the 1st. drugs of choice in early CHF. They have been proven to increase the quality of life and to prolong life. They work by decreasing the work of the heart by decreasing the peripheral resistance against which the heart muscle must work. They also work on the kidney vessels to prevent them from deteriorating and compounding the congestive state. They do so by inhibiting the enzymes which tell the kidney to retain salt and water, a mechanism the body uses when the tissues do not receive enough oxygen and blood nutrients. In this case it is self-destructive. A new improved and more selective class of ACE Inhibitors has come on the market with great promise. (I will update that shortly).
.) Other types of peripheral vascular vasodilators exist and have been found to be beneficial in difficult CHF cases, which work on either the arteries or veins, such as Alpha Blockers or Nitroglycerine.
4.) Decrease the frenatic activity of the heart muscle so that it can relax, allowing more blood to enter its chambers without elevating the pressure.
A.) Beta Blockers - Unique in that these drugs allow the heart muscle to rest and slow down and thereby become more efficient, even in their weakened state. Of course, we do not want weakened muscles to fall asleep and not work at all, making the CHF worse, so these drugs must be carefully monitored.
Congestive Heart Failure occurs when the heart muscle is, either weakened or overburdened. It occurs because of the inability of the heart to effectively pump blood out into the lungs or to the rest of the body. This blood in the vessels, principally in the lungs, builds up increasing the pressure and causes fluid to leak out into the surrounding tissues, such as the air sacs, in the lungs, or the subcutaneous tissue in the extremities. Symptoms vary from Shortness of Breath to swelling of the lower extremities. Signs include liquid heard in the air sacs (rales), compressional swelling of the extremities (edema), and purplish fingers and/or toes (cyanosis), among others. Treatment is directed towards mobilization of fluid plus strengthening and reducing the stress on the heart muscle. So, diuretics, Ace Inhibitors, vasodilators, Ionotropic agents and Beta blockers may be employed, separately or together to effect this relief.