Syncope in pulmonary embolism: a retrospective cohort study.

Objective: To determine the prevalence of syncope or collapse in pulmonary embolism (PE).

Methods: A retrospective cohort study was conducted. We examined the frequency with which syncope or collapse (presyncope) occurred alone or with other symptoms and signs in an unselected series of 224 patients presenting to a district general hospital with PE between September 2012 and March 2016. Confirmation of PE was by CT pulmonary angiogram in each case.

Results: Our cohort of 224 patients comprised 97 men and 127 women, average age 66 years with age range of 21-94 years. Syncope or collapse was one of several symptoms and signs that led to a diagnosis of PE in 22 patients (9.8%) but was never the sole presenting feature. In descending order, these other clinical features were hypoxaemia (17 patients), dyspnoea (12), chest pain (9), tachycardia (7) and tachypnoea (7). ECG abnormalities reported to occur more commonly in PE were found in 13/17 patients for whom ECGs were available. Patients with PE presenting with syncope or collapse were judged to have a large clot load in 15/22 (68%) cases.

Conclusion: Syncope was a frequent presenting symptom in our study of 224 consecutive patients with PE but was never the sole clinical feature. It would be difficult to justify routine testing for PE in patients presenting only with syncope or collapse.