Clinical research on the care of patients with loss of consciousness (syncope)
Our clinical research group focuses on syncope (loss of consciousness), a frequent symptom (1 to 3% of visits in emergency departments) representing the clinical expression of a wide spectrum of disease entities with very different prognosis depending on the underlying mechanism. For example a vasovagal syncope has an excellent prognosis, on the opposite a cardiac syncope (arrhythmia) has a poor prognosis. Specifically, our aims are : 1) to improve our knowledge on the epidemiology of syncope in emergency departments ; 2) to analyse the diagnostic performance of the different tests currently available in the work-up of syncope, including basic non invasive tests (clinical history, physical examination, 12-lead ECG) as well as specialized cardiovascular tests such as upright tilt testing or electrophysiological tests ; 3) to develop rational diagnostic strategies based on the probability of the underlying mechanism ; 4) to prospectively validate through pragmatic studies the diagnostic yield of these strategies ; and 5) to study the cost-effectiveness of these strategies.
During the past years, our group contributed to the introduction and validation of sequential diagnostic strategies for syncope from the emergency department to specialized inpatient testing. The diagnostic yield of several widely available test such as orthostatic testing and the role of echocardiography in the work-up of syncope have been precised. A clinical score based on clinical features readily available in the emergency department to predict the risk of cardiac arrhythmias has been developed and validated. Finally, a prospective multicentric study (Geneva and Lausanne) aiming at validating an algorithm for evaluating patients with unexplained syncope is under study. This algorithm relies on patient’s prognosis, the diagnostic yield of currently available diagnostic tests and on the available knowledge on the presence of underlying heart disease.