1) Symptoms due to pulmonary congestion: When the heart is unable to adequately fill with blood, the pressures inside the heart increase, and the blood "backs up" into the lungs, causing a condition known as pulmonary (or lung) congestion. Patients with pulmonary congestion often experience increasing shortness of breath, most often during exertion or while lying down. As the heart failure progresses, these symptoms can gradually increase to the point of producing physical incapacity. Severe and often sudden episodes of shortness of breath can also occur. These episodes, called "acute pulmonary edema," constitute medical emergencies. To make matters worse, in many patients with heart failure, changes occur in blood hormones and in the kidneys that cause salt and water retention. This fluid retention leads to swelling (or edema) in the legs, and in more pulmonary congestion. Symptoms of pulmonary congestion are common in all three types of heart failure.
2) Symptoms due to poor cardiac pumping action: Generally, symptoms caused by poor cardiac pumping (also referred to as decreased cardiac output) are seen only relatively late in the course of dilated cardiomyopathy, when the heart muscle has become extremely weak. (Because hypertrophic cardiomyopathy and diastolic heart failure are both characterized by relatively well-preserved cardiac pumping action, such symptoms are generally uncommon in these conditions.) When the heart muscle becomes weakened, the heart can no longer pump enough blood to sufficiently supply the body's organs. The most prominent symptoms caused by this poor pumping action are extreme fatigue and muscle wasting. However, poor blood flow can also reduce the function of internal organs including the brain, liver, kidneys, and intestines, leading to a host of additional symptoms such as lethargy, extreme edema (swelling), abdominal distention, and numerous gastrointestinal symptoms.
3) Symptoms due to cardiac arrhythmias: Heart failure of all three types are associated with heart rhythm disturbances. The most common is atrial fibrillation. The likelihood of developing atrial fibrillation continually increases as the heart failure worsens. You can read all about atrial fibrillation here. Unfortunately, sudden death due to ventricular tachycardia or ventricular fibrillation (very rapid and disorganized heart rhythms originating in the ventricles) is disturbingly common in patients with heart failure - especially in patients with dilated cardiomyopathy, and some forms of hypertrophic cardiomyopathy. Almost one out of three patients with dilated cardiomyopathy dies suddenly from ventricular arrhythmias. For this reason, patients with significant dilated cardiomyopathy should be considered for implantable defibrillators.
More on Heart Failure
Additional Links Related to Heart Failure
Sources:
Massie, BM "Heart Failure" in: Goldman L and Ausiello D (Eds). Cecil Textbook of Medicine, WB Saunders, 2003
