A dedicated investigation unit improves management of syncopal attacks (Syncope Study of Unselected Population in Malmö—SYSTEMA I)

AIMS: To investigate whether a systematic approach to unexplained syncopal attacks based on the European Society of Cardiology guidelines would improve the diagnostic and therapeutic outcomes. METHODS AND RESULTS: Patients presenting with transient loss of consciousness to the Emergency Department of Skåne University Hospital in Malmö were registered by triage staff. Those with established cardiac, neurological, or other definite aetiology and those with advanced dementia were excluded. The remaining patients were offered evaluation based on an expanded head-up tilt test protocol, which included carotid sinus massage, and nitroglycerine challenge if needed. Out of 201 patients registered over a period of 6 months, 129 (64.2%) were found to be eligible; of these, 101 (38.6% men, mean age 66.3 ± 18.4 years) decided to participate in the study. Head-up tilt test allowed diagnoses in 91 cases (90.1%). Vasovagal syncope (VVS) was detected in 45, carotid sinus hypersensitivity (CSH) in 27, and orthostatic hypotension (OH) in 51 patients. Twelve patients with VVS and 15 with CSH also had OH, whereas 25 were diagnosed with OH only. In a multivariate logistic regression, OH was independently associated with age [OR (per year): 1.05, 95% CI 1.02–1.08, P = 0.001], history of hypertension (2.73, 1.05–7.09, P = 0.039), lowered estimated glomerular filtration rate (per 10 mL/min/1.73 m(2): 1.17, 1.01–1.33, P = 0.032), use of loop diuretics (10.44, 1.22–89.08, P = 0.032), and calcium-channel blockers (5.29, 1.03–27.14, P = 0.046), while CSH with age [(per year) 1.12, 1.05–1.19, P < 0.001), use of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (4.46, 1.22–16.24, P = 0.023), and nitrates (27.88, 1.99–389.81, P = 0.013). CONCLUSION: A systematic approach to patients presenting with unexplained syncopal attacks considerably increased diagnostic efficacy and accuracy. Potential syncope diagnoses have a tendency to overlap and show diversity in demographic, anamnestic, and pharmacological determinants.