Heart Failure

Heart failure develops when the heart cannot effectively fill or contract w/ adequate strength to function as a pump to meet the needs of the body. As a result, cardiac output falls, leading to decreased tissue perfusion. The body initially adjusts to reduced cardiac output by activating compensatory mechanisms to restore tissue perfusion. These normal mechanisms may result in vascular congestion -- hence, the commonly used term congestive heart failure. As these mechanisms are exhausted, heart failure ensues, w/ increased morbidity and mortality.

Depending upon the cause, HF presents initially as right sided heart failure or left sided heart failure; as it progresses, the other side becomes affected

Left heart failure:

• the left ventricle has reduced capacity to pump blood into systemic circulation causing decreased cardiac output and stasis or backup of blood into the pulmonary circulation
• due to coronary artery disease, hypertension, cardiomyopathy, rheumatic heart disease
• Presenting symptoms: dyspnea on exertion (1st sign), orthopnea, PND, new s3, crackles; pulmonary edema.

Right heart failure:

•  the right ventricle has reduced capacity to pump blood into pulmonary circulation causing stasis or back up of blood into the venous circulation
• due to COPD, pulmonary embolism, rv infarct
• usually called cor pulmonale
• Presenting symptoms: edema of lower extremities, jugular venous distention, abdominal discomfort and nausea occur from fluid congestion in the abdominal organs

Both sides:

•  Presenting symptoms are unexplained fatigue, decrease exercise tolerance, unexplained altered mental status

Further clarification:

• Fall in cardiac output activates mechanisms that cause increased salt and water retention which causes weight gain and further increases pressures in the capillaries, resulting in edema
• Nocturia develops as edema fluid from dependent tissues is reabsorbed when the patient is supine
• Paroxysal nocturnal dyspnea, a frightening condition in w/c the pt. awakens at night acutely short of breath. It occurs when edema fluid that has accumulated during the day is reabsorbed into the circulation at night, causing fluid overload and pulmonary congestion
• Congestive hepatomegaly and splenomegaly caused by engorgement of the portal venous system results in increased abdominal pressure, ascites and GI problems. 
• Prolonged RHF may lead to impaired liver function

Main goals for care:

• slow progression
• reduce cardiac workload
• improve cardiac function
• control fluid retention