RESUMEN
BACKGROUND Right ventricular (RV) failure can result from acute or chronic cardiac or pulmonary conditions, or both, resulting in increased afterload, reduced contractility, changes in preload, ventricular interdependence, or dysrhythmias. Notably, increased afterload, particularly among previously healthy individuals, is often the primary cause of RV failure in cases of pulmonary and cardiac origin. Massive pulmonary thromboembolism is a common cause of impending RV failure, and chronic conditions like atrial septal defects can also contribute to pulmonary hypertension. CASE REPORT A 72-year-old patient, with no known past medical history, presented to the emergency department in profound shock, rapidly progressing to cardiorespiratory arrest. Bedside ultrasound revealed marked right chambers dilatation, severe mitral and tricuspid insufficiency, a large atrial septal defect, mild pericardial effusion, and global hypokinesia. This case illustrates how multiple mechanisms of RV dysfunction can converge, leading to fulminant RV failure and subsequent cardiac arrest, including increased afterload, decreased contractility, dysrhythmias, and ventricular interdependence. CONCLUSIONS This article emphasizes the usefulness of bedside ultrasound in diagnosing and elucidating the causes of circulatory collapse. In this patient, ultrasound played an important role in identifying 3 contributing factors: chronic RV overload from an extensive atrial septal defect, left ventricular impact due to ventricular interdependence, and acute pulmonary thromboembolism. Being aware of these factors, along with the practicality of bedside ultrasound, allowing emergency physicians to make prompt diagnoses and effectively manage RV failure-related emergencies.