- Orthopnea, paroxysmal nocturnal dyspnea, dyspnea at rest
and during exertion, fatigue.
- Jugular vein distention, peripheral pitting edema, sinus tachycardia,
basilar rales or coarse bubbling rales throughout both lung fields,
cardiomegaly, S3 gallop sound, liver enlargement.
- Left ventricular systolic or diastolic dysfunction.
Congestive heart failure (CHF) is a complex clinical syndrome characterized by dysfunction of the left, right, or both ventricles
and the resultant changes in neurohormonal regulation. This syndrome is accompanied by effort intolerance, fluid retention, and shortened survival. It is often a terminal stage of heart disease, occurring after all reserve capacity and compensatory mechanisms of the myocardium
and peripheral circulation have been exhausted. Initially, the syndrome was described as a state of fluid overload with congestion of the lungs caused by a failing heart. It is, however, now well recognized that in many patients the predominant symptom may be a reduction of functional
capacity because of poor exercise tolerance associated with limited cardiac reserve.
Heart failure results from myocardial dysfunction that impairs the heart’s ability to circulate blood at a rate sufficient
to maintain the metabolic needs of peripheral tissues and various
organs. It follows myocardial damage when the compensatory hemodynamic
and neurohormonal mechanisms are overwhelmed or exhausted and results
from the loss of a critical amount of functioning myocardium due
to acute myocardial infarction (MI), prolonged cardiovascular stress (hypertension,
valvular disease), toxins (eg, alcohol abuse), or infection; in
some cases, there is no apparent cause (idiopathic cardiomyopathy).
Heart failure is a relatively common clinical disorder, estimated to affect more than 5 million patients in the United States. Each
year, new cases of CHF develop in about 550,000 patients. Morbidity
and mortality rates are high; annually, approximately 1 million
patients require hospitalization for CHF, approximately 6.5 million
hospital-days. Each year 50,000 to 60,000 patients die of this condition.
Approximately one-third to one-half of the deaths in patients with CHF are secondary to the progression of cardiac insufficiency
and its associated conditions. The remainder of the patients with CHF
die of sudden cardiac death, presumably related to electrical instability and
ventricular arrhythmias and other cardiovascular conditions as well
as from noncardiovascular causes.
Data describing the natural history of CHF are limited because this condition has not been extensively studied in a prospective manner. The Framingham heart study showed that men in whom clinical symptoms of CHF developed had a 62% probability of dying within 5 years of the onset of symptoms. Subsequent studies in patients with dilated or congestive cardiomyopathy indicate that heart failure is a progressively deteriorating condition, with 20–40% of patients dying within 5 years after the onset of illness; other studies show that patients with advanced CHF (New York Heart Association [NYHA] class IV) have a 40–50% annual mortality rate.
When an excessive workload is imposed on the heart by increased systolic blood pressure (pressure overload), increased diastolic
volume (volume overload), or loss of ...