Fig. 1

Clinical-ultrasound integrated diagnostic approach to the patient with suspected congestive heart failure, focused on the diagnosis of heart failure (HF) with preserved ejection fraction (HFpEF). When facing respiratory distress, and congestive heart failure is suspected, history and a brief clinical exam should screen for cardiovascular risk factors, typical signs/symptoms of heart failure and for potential precipitating factors (step A). Multi-organ bedside ultrasound follows (step B), starting from lung ultrasound (B1): a pattern of bilateral, symmetrical, homogeneously diffuse scans with multiple B-lines (more than 2 positive chest areas per side = sonographic interstitial syndrome) [32] is diagnostic for pulmonary edema. A potential cardiac etiology of this pulmonary congestion is then screened for with Focused Cardiac Ultrasound (B2): the finding of moderate-severe left ventricular systolic dysfunction raises high suspicion for congestive high failure with reduced ejection fraction (HFrEF). This can then be confirmed with the echocardiographic demonstration of high left atrial filling pressures. Alternatively, FoCUS findings of gross valvular dysfunction or pure volume overload (if consistent with history) will suggest a different cardiogenic or a hydrostatic cause of the pulmonary edema. Immediate or delayed comprehensive echocardiography will again confirm the diagnosis and clarify the mechanism and degree of valvular dysfunction. When all the FoCUS findings consistent with potential causes of pulmonary edema are ruled out, comprehensive echocardiography (B3) is even more required to confirm/rule out a likely diagnosis of heart failure with preserved ejection fraction (HFpEF, defined as ejection fraction ≥ 50%, with TDI and Doppler indices diagnostic for elevated left atrial pressures, with/without left ventricular hypertrophy or left atrial enlargement [2]). The diagnosis of HFpEF finally requires a concomitant positive natriuretic peptides assay (step C). Natriuretic peptides must in any case be pathological for the diagnosis of any alternative cardiogenic cause of pulmonary edema (either HFrEF or HF caused by valvular dysfunction). HTN hypertension, CVD cardiovascular disease, HF heart failure, ECG electrocardiography, NSAIDS non steroid anti-inflammatory drugs, LUS lung ultrasound, FoCUS focused cardiac ultrasound, IVC inferior vena cava, LV left ventricle, EF ejection fraction, LAP left atrial pressure, LAE left atrial enlargement, HFpEF heart failure with preserved ejection fraction, HFrEF heart failure with reduced ejection fraction, BNP brain natriuretic peptide