The emergency department (ED) plays a critical role in the initial diagnosis and management of acute heart failure (AHF),1,2 as nearly 80 % of all AHF admissions originate from the ER.3 However, patients do not present with a diagnosis; rather they present with a chief complaint reflecting signs and symptoms – most commonly breathlessness. Differentiating AHF from other causes of breathlessness can be challenging, especially in patients with multiple co-morbid conditions such as chronic heart failure and chronic obstructive pulmonary disease (COPD). Failure to diagnose correctly leads to delays or mistreatment, potentially leading to worsened outcomes. Determining whether breathlessness is cardiac or non-cardiac in origin is a critical step in management.
In this article, the authors review the role of focused cardiac and pulmonary ultrasound in the diagnosis and management of dyspnoeic emergency patients, with a specific focus on AHF. Importantly, point- of-care cardiac ultrasound does not replace formal echocardiography (ECG).4,5 As the training requirements for focused ultrasound are beyond the scope of this review, readers should refer elsewhere.6,7
Clinical Case Study
A 68-year-old man presents to the ER complaining of shortness of breath for the past three days, progressively worsening. He has a low-grade fever and his initial vital signs are as follows: HR 109, BP 158/81, RR 20, Sa02 97 % on room air. He has a history of coronary artery disease with two stents placed two years ago. He also has a long history of smoking and has COPD. He has no known history of heart failure but does report increase dyspnoea on exertion, but denies paroxymal nocturnal dyspnoea and orthopnoea. On examination, he is in mild distress, but able to speak in complete sentences. His heart is regular, but fast with no murmurs, gallops or rubs. Faint expiratory wheezes bilaterally are audible. He is mildly obese and jugular venous distention is not ascertained, despite hepatic pressure. He has trace pitting oedema bilaterally. Electrocardiogram (ECG) shows sinus tachycardia, but no acute ischaemic changes.
Background
AHF is a clinical diagnosis. Similar to other diagnostic studies, such as chest radiography and biomarkers, ulstrasound is not intended to be a stand-alone test. Rather, focused ultrasound should be incorporated into the overall diagnosis and management of the AHF patient. The primary purpose of point-of-care cardiac and pulmonary ultrasound is to aid in clinical management. It may allow for earlier diagnosis of AHF and potentially identify alternative etiologies of acute dyspnoea. In other words, focused ultrasound may facilitate the correct diagnosis.4,6,8–13
Diagnosis
The authors recommend performing focused ultrasound during the initial encounter with the patient. Assuming critical life-saving interventions or immediate resuscitation are not required, focused ultrasound occurs immediately after the history, physical examination and ECG. As discussed in detail below, multiple studies demonstrate the utility of ultrasound to improve diagnostic accuracy in dyspnoeic ED patients.