PRECIPITANTS OF HEART FAILURE.
Patients with compensated heart failure have a high rate of readmission into the hospital with acute exacerbations. A number of studies have shown that a precipitant can be identified in two-thirds of cases of emergency admission for heart failure. Decompensation may occur as a result of failure or exhaustion of the compensatory mechanisms but without any change in the load on the heart in patients with persistent, severe pressure or volume overload. In particular, consider whether the patient has underlying coronary artery disease or valvular heart disease.
1. Severe infections in the body especially respiratory tract infections: Systemic infection or the development of unrelated illness can also lead to heart failure. Systemic infection precipitates heart failure by increasing total metabolism as a consequence of fever, discomfort, and cough, increasing the hemodynamic burden on the heart. Septic shock, in particular, can precipitate heart failure by the release of endotoxin-induced factors that can depress myocardial contractility.
2. Heart infections: Cardiac infections and inflammation can also endanger the heart. Inflammation of the heart muscle or infection of the inner lining may directly impair myocardial function and exacerbate existing heart disease. The anemia, fever, and fast heartbeat that frequently accompany these processes are also deleterious. In the case of infective endocarditis, the additional valvular damage that ensues may precipitate cardiac decompensation.
3. Inappropriate discontinuation of therapy: The most common cause of decompensation in a previously compensated patient with heart failure is inappropriate reduction in the intensity of treatment, such as dietary sodium restriction, physical activity reduction, or drug regimen reduction.
4. Uncontrolled Hypertension: Uncontrolled hypertension is the second most common cause of decompensation,
Progressive closure of already narrow aortic or mitral valves: A previously stable, compensated patient may develop heart failure that is clinically apparent for the first time when the intrinsic process (narrowing) has advanced to a critical point.
5. Abnormal heart rhythm: cardiac arrhythmias (most commonly, atrial fibrillation). Arrhythmias, particularly ventricular arrhythmias, can be life threatening.
6. Heart attack (Myocardial infarction): arising from severe inadequate blood flow to the heart caused by:
-Profoundly low blood level: Because of increased myocardial oxygen consumption and demand beyond a critical level.
-Pulmonary embolism: Patients with heart failure, particularly when confined to bed, are at high risk of developing pulmonary emboli, which can increase the hemodynamic burden on the right ventricle by further elevating right ventricular (RV) systolic pressure.
Intense, prolonged physical exertion or severe fatigue, such as may result from prolonged travel or emotional crisis, is a relatively common precipitant of cardiac decompensation.
The same is true of exposure to severe climate change (ie, the individual comes in contact with a hot, humid environment or a bitterly cold one).
Excessive intake of water and/or sodium and the administration of cardiac depressants, cancer drugs or drugs that cause salt retention (such as NSAID pain relievers) are other factors that can precipitate heart failure.