Table 2:

Serious adverse events among patients with syncope after disposition from emergency department

Serious adverse event	Location of adverse event; no. of patients
Serious adverse event	Total n = 147	In hospital n = 86	Outside hospital n = 61
Death	21	8	13
Known cause^*	7	5	2
Unknown cause	14	3^†	11
Cardiac	98	65	33
Arrhythmia
Sinus node dysfunction	18	10	8
New or uncontrolled atrial fibrillation	7	0	7
High-grade atrioventricular block	9	6	3
Ventricular arrhythmia	15	11	4
Supraventricular tachycardia	2	1	1
Pacemaker insertion	24	21	3
Other cardiac
Structural heart disease	11	9	2
Myocardial infarction	11	6	5
Aortic dissection	1	1	0
Noncardiac	35	18	17
Pulmonary embolism	8	6	2
Gastrointestinal bleeding	10	6	4
Other^‡	17	6	11

↵* Patients with a known cause of death had one of the cardiac or noncardiac serious adverse events and hence are not counted toward the total number of patients with serious outcomes.
↵† Multiple causes of death were reported in the medical records, with no clear indication of cause of death.
↵‡ Includes conditions that require acute treatment or that cause a patient to return to hospital if discharged home, such as renal failure requiring dialysis, sepsis, anemia requiring transfusion, acute abdominal conditions (i.e., bowel obstruction, acute appendicitis, ectopic pregnancy, acute presentation of intra-abdominal or pelvic cancer, and cholangitis), lung pathology (i.e., severe pulmonary hypertension, pulmonary fibrosis, and large pleural effusion), acute intracranial pathology (i.e., subarachnoid hemorrhage, posterior circulation stroke, brain tumour, brain metastasis, intracranial hemorrhage, subdural hematoma) and subclavian steal syndrome.