Heart Failure: Difference between revisions

=== Symptoms ===

HF can manifest with a multitude of different symptoms, but shortness of breath and tiredness are the most characteristic. Other symptoms include:

In general, correlation between the severity of symptoms and the severity of HF is weak (guidelines). The New York Heart Association functional classification is used most frequently to classify the severity of HF (table 2).  

Table 2 NYHA functional classification

Class IV Unable to carry on any physical activity without discomfort. Symptoms at rest. If any physical activity is undertaken, discomfort is increased.  

There are several key features in the clinical examination of a patient presenting with HF, and these include observation, palpitation and auscultation. The physical examination should focus on the general appearance of the patient, pulse and blood pressure, signs of fluid overload (increased jugular venous pressure, peripheral oedema, ascites and hepatomegaly), the lungs, and the heart (apex, Gallop rhythm, third heart sound, murmurs).

In order to assist in diagnosing HF and differentiate between causes, the following modalities are available.  

In every patient suspected of HF, an electrocardiogram (ECG) should be performed. Several common abnormalities (including possible causes) indicative of HF on the ECG include but are not limited to; sinus tachy- or bradycardia, atrial tachycardia, -flutter, or –fibrillation, ventricular arrhythmias, ischemia (including myocardial infarction), abnormal Q waves, left ventricular hypertrophy, micro voltages, and QRS length >120 ms. Allthough an abnormal ECG (exluding arrhythmias) has a low positive predictive value for HF, a normal ECG is highly indicative of the absence of HF.

A chest X-ray is a part of the standard examination in potential HF patients. Importantly, the x-ray is a tool to detect cardiomegaly or other possible cues that indicate HF. Also, it is important to rule out other causes of dyspnoea.  

Echocardiography is the cornerstone in diagnosing HF, and should routinely be performed, because ventricular function can be evaluated accurately with this technique. It can provide objective evidence of a structural or functional abnormality of the heart at rest besides signs and symptoms typical of heart failure. Important parameters that can be assessed include but are not limited to wall motion, valve function, and left ventricular ejection fraction and diastolic function. Diastolic dysfunction might be an important finding in symptomatic patients with a preserved ejection fraction. Please refer to Table 3 for common echocardiographic findings in HF. Transoesophageal echocardiography is indicated in patients with an inadequate thansthoracic echo window, suspected endocarditis, complicated valvular disease or to exclude a LV thrombus. If echocardiography provides inadequate information or in patients with suspected coronary artery disease, additional imaging includes CT scanning, cardiac magnetic resonance imaging or radionuclide imaging.

A standard blood assessment covers a complete blood count. Electrolytes, renal function, glucose and liver function. Furthermore, an urinalysis complete and other tests depending on the clinical condition complete the laboratory assessment.  For example, cardiac troponins must be sampled if an ACS is in the differential diagnosis. In patients suspected of HF, values of natriuretic peptides  atrial natriuretic peptide (ANP), N-terminal  ANP (NT-ANP), B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) can provide important information regarding diagnosis, management and prognosis of HF. Natriuretic peptides are enzymes, secreted by the atria or ventricles in response to myocardial wall stress. ANP and NT-ANP are secreted primarily by the atria, BNP and NT-proBNP mainly by the ventricles. These values are used for evaluating prognosis in patients with known HF, for defining medication dose, and for making a diagnosis in patients suffering shortness of breath. Especially for the last mentioned group, peptide counts can help differentiate between pulmonary- or cardiac problems when they present in the emergency room.  

This test is usually performed on a treadmill or on an ergo meter. The patient is asked to give maximal effort while the work load gradually increases. During the test, ECG is constantly monitored for ischemia. When possible, oxygen consumption should be measured during the test. Not only is an oxygen consumption test a good tool to discriminate between lung- peripheral- or heart problems, the obtained maximal oxygen uptake (VO2-max) also has an important prognostic value.  

Heart catheterization is not part of the routine diagnosis and work-up of patients with HF.  But in patients suffering angina pectoris despite optimal medical therapy, it should be considered (Class of recommendation IIa, level of evidence C, see table 4). Also, coronary angiography is recommended in patients at high risk of coronary artery disease  (Class of recommendation I, level of evidence C) and in HF patients with significant valvular disease (Class of recommendation IIa, level of evidence C).