Most of patients with heart failure present a left ventricular systolic dysfunction usually, if not always, associated with a diastolic dysfunction. Clinical manifestations and physical examination allows a presumed diagnosis. Some signs guide toward a systolic heart failure: deviation of cardiac impulse, protodiastolic gallop, functional mitral insufficiency, radiological cardiomegaly associated with signs of postcapillary hypertension, anterior Q wave or complete left bundle branch block. Bed-side dosage of B-type natriuretic peptide is useful to make or exclude the diagnosis of heart failure in patients with acute dyspnea from various causes. Doppler echocardiography is essential to confirm the left ventricular systolic dysfunction and its mechanism: ischemic, valvular or myocardial. The value of shortening fraction is better than eye evaluation. Coronary angiography is indicated when the mechanism of heart failure is unclear and if the patient is relevant to revascularization.