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- Patients are admitted to the intensive care unit (ICU) with manifestations of acute heart failure (AHF) that arise in three general contexts: decompensation of chronic heart failure, as a complication of a cardiac process such as ischemia or valve incompetence, and when cardiomyopathy complicates other critical illness.
- Determining which of the contexts of AHF is present is invaluable to guide therapy.
- Predominant signs and symptoms arise from venous congestion after elevation of ventricular end-diastolic pressure and hypoperfusion; in a given patient, different contributions of these processes may be present.
- Measurement of brain natriuretic peptide has been a useful addition to the diagnostic armamentarium to determine whether heart failure is a cause of acute dyspnea; this measurement is most useful when obtained acutely and before initiation of therapies and, hence, has a limited role for assessing patients after admission to the ICU.
- Echocardiography is an extremely useful tool to assess ventricular function and define cardiac anatomy; on occasion, information from invasive measurement of intravascular pressure or venous oxygen saturation is also required to guide therapy.
- Many patients will exhibit respiratory distress and different degrees of impaired oxygenation; whereas many, if not most, patients can be managed with oxygen for this component of AHF, ventilatory support in the form of continuous positive airway pressure or bilevel airway support (BiPAP) should be considered for patients not responding adequately to oxygen therapy alone or whose respiratory symptoms and findings are severe from the onset.
- Diuretics are useful for treating venous congestion and inotropes for inadequate perfusion, but each carry risk of excessive dosing; the mainstay of therapy for most patients should be afterload reduction and search for the underlying causes of ventricular dysfunction and decompensation.
- Vasoconstrictive agents should be used only when and as long as truly life-threatening hypotension is present
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Acute heart failure (AHF) is the primary or an underlying diagnosis in many patients admitted to the intensive care unit (ICU), but its exact incidence is unknown. The cause of heart failure (HF) in 60% to 70% of hospitalized patients is ischemic heart disease,1–3 but many diagnoses, including arrhythmias, idiopathic dilated cardiomyopathy, systemic or pulmonary hypertension, congenital and valvular heart disease, or myocarditis, should be considered (see Chap. 24). HF is complicated by diabetes in 27% of hospitalized patients, renal dysfunction in 17%, and respiratory disease in 32%, and the vast majority of individuals hospitalized for AHF are older than 70 years.3
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AHF may present with left or right HF or the combination of these conditions. The cardiac dysfunction may be systolic or “diastolic” (with preserved ejection fraction), and the underlying pathogenetic mechanism may be cardiac or extracardiac and may induce transient or permanent cardiac damage.4 Especially in the ICU, multiple extracardiac pathologies may result in AHF by changing preload, afterload, or contractility, including pericardial disease, renal failure, endocrinopathy, sepsis, thyrotoxicosis, anemia, end-stage liver disease, and central nervous system lesions. Some rare cardiac pathologies also may be responsible for AHF, ...