From the Guidelines
Syncope evaluation should begin with a thorough history, physical examination, and 12-lead ECG for all patients. The history should focus on circumstances surrounding the event, prodromal symptoms, position at onset, and any associated symptoms 1. Physical examination should include orthostatic vital signs, cardiovascular assessment, and neurological evaluation. Risk stratification is essential to determine which patients need hospitalization versus outpatient management. High-risk features include age >60, history of cardiac disease, abnormal ECG, syncope during exertion, syncope without warning, or family history of sudden cardiac death.
Key Components of Evaluation
- A meticulous history to determine the cause of syncope with great accuracy 1
- Physical examination including orthostatic blood pressure measurements and standard electrocardiogram (ECG) 1
- Assessment of the medication list for agents associated with proarrhythmia 1
Further Testing and Treatment
For patients with suspected cardiac syncope, further testing may include echocardiography, prolonged cardiac monitoring (Holter or event monitor for 2-4 weeks), or tilt-table testing. If neurological causes are suspected, brain imaging (MRI or CT) and EEG may be appropriate 1. For recurrent unexplained syncope, implantable loop recorders can monitor for up to 3 years. Treatment depends on the underlying cause: cardiac syncope may require antiarrhythmic medications, pacemaker, or ICD; vasovagal syncope often responds to increased salt and fluid intake, compression stockings, and occasionally medications like midodrine (2.5-10mg three times daily) or fludrocortisone (0.1-0.2mg daily). Orthostatic hypotension may require medication adjustments, compression stockings, and adequate hydration. Prompt evaluation is crucial as syncope can be the first presentation of life-threatening conditions, particularly in those with structural heart disease.
From the Research
Syncope Evaluation
- Syncope is a complex presenting symptom defined by a transient loss of consciousness, usually accompanied by falling, and with spontaneous recovery 2.
- The evaluation of syncope begins with a careful history, physical examination, and electrocardiography, with additional testing based on the initial clinical evaluation 2, 3, 4.
- Syncope can be classified into four categories: reflex mediated, cardiac, orthostatic, and cerebrovascular, with cardiac cause associated with significantly higher rates of morbidity and mortality than other causes 2, 4.
Diagnostic Approach
- A thorough history and physical examination, including orthostatic assessment, are crucial for making the diagnosis 3, 4, 5.
- Short-term risk assessment should be performed to determine the need for admission, with inpatient evaluation needed for high-risk patients and outpatient evaluation recommended for low-risk patients 3, 4.
- Electrocardiography is a mandatory diagnostic tool, although normal in the majority of patients with syncope, it has the potential to identify patients with high likelihood of cardiac syncope due to arrhythmic or cardiopulmonary disorder 5.
Testing and Risk Stratification
- Additional testing, such as prolonged electrocardiographic monitoring, echocardiography, and exercise stress testing, may be beneficial in patients at higher risk of adverse outcomes from cardiac syncope 2, 4.
- Risk stratification tools, such as the Canadian Syncope Risk Score, may be beneficial in informing decisions regarding hospital admission 4.
- Neuroimaging should be ordered only when findings suggest a neurologic event or a head injury is suspected, and laboratory tests may be ordered based on history and physical examination findings 2, 4.