Syncope and COVID-19 disease – a systematic review

Background Syncope is not a common manifestation of COVID-19, but it may occur in this context and it can be the presenting symptom in some cases. Although several mechanisms may explain the pathophysiology behind COVID-19 related syncope, a valid relationship has not been established yet. In this systematic review, we aimed to examine the current incidence of syncope in COVID-19 patients and to explore different patterns observed in this setting. Methods A systematic review across PubMed, ISI Web of Knowledge and SCOPUS was performed, according to PRISMA guidelines, in order to identify all relevant articles regarding both COVID-19 and syncope. Results We identified 81 publications, of which 62 were excluded. The cumulative incidence of syncope and pre-syncope across the selected studies was 7.1% (256/3584 patients). Unspecified syncope was the most common type (76.2% of the reported episodes), followed by reflex syncope (18.1% of the cases). Orthostatic hypotension was responsible for 3.6% of the cases and syncope of presumable cardiac cause accounted for 2.0%. Arterial hypertension was present in 64.7% of the patients and either angiotensin receptor blockers or angiotensin converting enzyme inhibitors were used by 39.5% of hypertensive patients with syncope. Conclusion Syncope, although not considered a typical symptom of the COVID-19 disease, can be associated with it, particularly in early stages. Different types of syncope were seen in this context, each with different implications requiring distinct approaches. A careful reevaluation of blood pressure whenever a patient develops COVID-19 is suggested, including reassessment of antihypertensive therapy.