Red flags Certain findings raise suspicion of a more serious etiology of chest pain: Abnormal vital signs (tachycardia, bradycardia, tachypnea, hypotension) Signs of hypoperfusion (eg, confusion, ashen color, diaphoresis) Shortness of breath Hypoxemia on pulse oximetry Asymmetric breath sounds or pulses New heart murmurs Pulsus paradoxus > 10 mm Hg Interpretation of findings Symptoms and signs of thoracic disorders vary greatly, and those of serious and nonserious conditions often overlap.