From the Guidelines
Seated syncope can occur in various situations, including those with serious medical conditions, such as arrhythmic or cardiac causes, which may require hospital evaluation and treatment, as recommended by the 2017 ACC/AHA/HRS guideline 1. When considering the potential situations for seated syncope, it is essential to prioritize the evaluation and management of patients with serious medical conditions that may be relevant to the cause of syncope. According to the 2017 ACC/AHA/HRS guideline 1, hospital evaluation and treatment are recommended for patients presenting with syncope who have a serious medical condition potentially relevant to the cause of syncope identified during initial evaluation. Some key situations that may lead to seated syncope include:
- Arrhythmic causes, which may require consideration of pacemaker/implantable cardioverter-defibrillator (ICD) placement or revision and/or medication modification, as outlined in the guideline 1
- Cardiac causes, which require treatment of the underlying condition, such as medication management and consideration of surgical intervention for critical aortic stenosis, as recommended by the guideline 1
- Noncardiac serious conditions, such as severe anemia from a gastrointestinal bleed, which may require management of the underlying problem, as noted in the guideline 1 It is also important to consider that patients with presumptive reflex-mediated syncope, such as vasovagal syncope (VVS), can be managed in the outpatient setting in the absence of serious medical conditions, as suggested by the guideline 1. However, hospital-based evaluation may be necessary for patients with frequent recurrent syncope, risk of injury, or identified injury related to syncope, as indicated by the guideline 1.
From the Research
Potential Situations for Seated Syncope
Seated syncope, or fainting while sitting, can occur in various situations. Some potential causes and situations include:
- Reflex syncope, which may be challenging to treat due to its complex pathophysiological mechanism 2
- Orthostatic hypotension, which can be easily detected and may be managed with simple measures or drug treatments 3
- Cardiac syncope, which is more likely to be associated with adverse outcomes and may require additional testing, such as prolonged electrocardiographic monitoring or echocardiography 4
- Systemic vasodilation or decreased cardiac output, which can lead to cerebral hypoperfusion and syncope 4
Risk Factors and Triggers
Certain risk factors and triggers may contribute to seated syncope, including:
- Abrupt drop in systemic blood pressure 5
- Cardiac structural disease or channelopathies, which may increase the risk of sudden cardiac death 5
- Neurogenic or reflex causes, such as adenosine-sensitive syncope or idiopathic atrioventricular block 2
- Orthostatic challenge, such as active standing, which can help detect orthostatic hypotension 3
Diagnostic Considerations
Diagnosing the cause of seated syncope is crucial to initiate effective therapy. Evaluation may involve:
- History and physical examination, including orthostatic blood pressure measurements 4
- Electrocardiographic results and additional testing, such as stress testing or echocardiography, if cardiac syncope is suspected 4
- Risk stratification tools, such as the Canadian Syncope Risk Score, to inform decisions regarding hospital admission 4