Describe the BNP.
BNP (or NT-proBNP): useful for diagnostic confirmation and prognostication; can be measured serially to guide therapy
Should always be interpreted in comparison to the patient's baseline and in the context of history, examination, and imaging.
High diagnostic utility in patients with an unclear diagnosis
List additional blood tests.
Troponin: to rule out ACS
Consider thyroid function tests.
Measuring BNP (or NT-proBNP) is especially helpful in patients with an unclear diagnosis. BNP has a high diagnostic value when combined with a physical examination and imaging.
In a patient presenting with acute dyspnea, a low BNP (or NT-proBNP) makes a diagnosis of acute heart failure very unlikely.
Describe the ECG.
ECG findings in acute heart failure are variable and may include: 
Acute ischemic changes due to ACS (see “Diagnosis of myocardial infarction”)
Left ventricular hypertrophy
Bundle branch block
Nonspecific ST segment changes
Low voltage QRS 
ECG findings may be normal.
Describe findings of Chest x-ray (initial imaging).
X-ray findings in pulmonary congestion
Enlarged heart shadow due to cardiomegaly and/or pericardial effusion 
Kerley B lines (also known as septal lines)
Prominent pulmonary vessels and perihilar alveolar edema (the hilar shadow has a butterfly or “bat wing” appearance)
Basilar interstitial edema
Bilateral pleural effusions 
Cephalization: increased prominence of pulmonary vessels in the upper lobes of the lungs due to venous congestion 
ABCDE: Alveolar edema (bat wings), Kerley B lines (interstitial edema), Cardiomegaly, Dilated prominent pulmonary vessels, and Effusions
List findings of TTE.
Indications: all patients with suspected acute heart failure (imaging modality of choice) 
Characteristic echocardiographic findings of AHF
Reduced or normal LVEF 
Left atrial dilation, valvular disorders 
Right ventricular systolic dysfunction, increase in right ventricular systolic pressure