Congestive heart failure (CHF) has become one of the most common diseases in the United States. Over 5 million people in the United States are living with CHF, and over 650,000 new cases are diagnosed each year. While this disease is associated with significant morbidity and mortality, quality of life and survival may be improved with appropriate lifestyle modifications and medical and device-based therapy.
CHF occurs with impaired myocardial filling and/or contraction. This results in either the heart’s inability to pump a sufficient amount of oxygenated blood and nutrients to meet the body’s needs, or the heart’s ability to pump blood effectively only by elevating the filling pressures. A manifestation of acute CHF is pulmonary edema, the backup of blood from the left heart into the lungs. Heart failure may be due to myocardial damage (ischemia, longstanding hypertension, the effects of alcohol, etc.).
CHF is the result of an imbalance in the degree of end-diastolic fiber stretch proportional to the systolic mechanical work achieved. This imbalance can produce a malfunction between mechanisms that keep the interstitium and the alveoli dry and the competing forces that result in fluid transfer to the interstitium. The mechanisms that keep the interstitium and the alveoli dry are the maintenance of plasma oncotic pressure higher than pulmonary capillary pressure, maintenance of connective tissue and cellular barriers relatively impermeable to plasma proteins, and maintenance of a vast lymphatic system.