Exercise stress echocardiography with ABCDE protocol in unexplained dyspnoea

Current guidelines recommend the use of exercise stress echocardiography (ESE) in patients with unexplained dyspnoea. SE was recently reshaped with the ABCDE protocol: A for asynergy, B for B-lines (4-site simplified scan), C for contractile reserve based on force, D for Doppler-based coronary flow velocity reserve (CFVR) in left anterior descending coronary artery; and E for EKG-based heart rate reserve (HRR, defined as peak/rest HR < 1.62). Aim of the study was to define the ESE response in patients with dyspnoea as the main symptom. From the initial population of patients referred in 2018 in a single center for semi-supine ESE, we selected two groups (without history of previous myocardial infarction or coronary revascularization) on the basis of the main presenting symptom: dyspnoea (Group 1, n = 100, 62 men, 63 ± 10 years) or chest pain (Group 2, n = 100, 58 men, age 61 ± 8 years). All underwent ESE with ABCDE protocol. Success rate was 100% for steps A, B, C, E, and 88% for step D. Positivity for A criterion occurred in 56 patients of Group 1 and 24 of Group 2 (p < 0.0001). B-lines positivity (stress > rest for ≥ 2 points) occurred in 40 patients of Group 1 and 28 of Group 2 (p = 0.07). LVCR positivity (< 2.0) occurred in 60 patients of Group 1 and 42 of Group 2 (p < 0.05). A reduced CFVR occurred in 56 of Group 1 and 22 of Group 2 (p < 0.0001). A blunted HRR was present in 44 patients of Group 1 and 22 of Group 2 (p < 0.001). In conclusion, in patients with unexplained dyspnoea, SE with ABCDE protocol is useful to document the cardiac origin of dyspnoea with a comprehensive assessment focused not only on ischemia (A) but also pulmonary congestion (B), myocardial scar or necrosis (C), coronary microvascular dysfunction (D) or chronotropic incompetence (E).