2017 ACC/AHA/HRS晕厥评估指南

1. 晕厥的初始评估流程：
   

2.1 History and Physical Examination: Recommendation

A detailed history and physical examination should be performed in patients with syncope (I).

The history should aim to identify the prognosis, diagnosis, reversible or
ameliorable factors, comorbidities, medication use, and patient and family needs. Cardiac syncope carries a significantly worse prognosis than does neurally mediated syncope. Prognostic factors generally separate neurally mediated from cardiac syncope and are described in Section 2.3.3. The diagnostic history focuses on the situations in which syncope occurs, prodromal symptoms that provide physiological insight, patient’s self-report, bystander observations of the event and vital signs, and post-event symptoms. Video recordings are helpful when available. Time relationship to meals and physical activities and duration of the prodrome are helpful in differentiating neurally mediated syncope from cardiac syncope. Comorbidities and medication use are particularly important factors in older patients. A history of past medical conditions should be obtained,particularly with regard to the existence of preexisting cardiovascular disease. A family history should be obtained, with particular emphasis on histories of syncope or sudden unexplained death (or drowning). Historical characteristics associated with, though not diagnostic of, cardiac and noncardiac syncope are summarized in Table 4.The physical examination should include determination of orthostatic blood pressure and heart rate changes in lying and sitting positions, on immediate standing, and after 3 minutes of upright posture. Careful attention should be paid to heart rate and rhythm, as well the presence of murmurs, gallops, or rubs that would indicate the presence of structural heart disease. A basic neurological examination should be performed, looking for focal defects or other abnormalities that would suggest need for further neurological evaluation or referral.

Historical Characteristics Associated With Increased Probability of Cardiac and Noncardiac Causes of Syncope

2.2 Electrocardiography: Recommendation

In the initial evaluation of patients with syncope, a resting 12-lead electrocardiogram (ECG) is useful (I).

2.3 Risk Assessment: Recommendations

Evaluation of the cause and assessment for the short- and long-term morbidity and mortality risk of syncope are recommended (Table 5)(I).

Use of risk stratification scores may be reasonable in the management of patients with syncope (IIb).

2.4 Recommendations for Disposition After Initial Evaluation

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 (I).

It is reasonable to manage patients with presumptive reflex-mediated syncope in the outpatient setting in the absence of serious medical conditions(IIa).

In intermediate-risk patients with an unclear cause of syncope, use of a structured ED observation protocol can be effective in reducing hospital admission (IIa).

It may be reasonable to manage selected patients with suspected cardiac syncope in the outpatient setting in the absence of serious medical conditions (IIb).

3. Additional Evaluation and Diagnosis

3.1. Blood Testing: Recommendations

Targeted blood tests are reasonable in the evaluation of selected patients with syncope identified on the basis of clinical assessment from history,physical examination, and ECG(IIa).

Usefulness of brain natriuretic peptide and high-sensitivity troponin measurement is uncertain in patients for whom a cardiac cause of syncope is suspected (IIb).

Routine and comprehensive laboratory testing is not useful in the evaluation of patients with syncope (III).

3.2. Cardiovascular Testing
3.2.1. Cardiac Imaging: Recommendations
Transthoracic echocardiography can be useful in selected patients presenting with syncope if structural heart disease is suspected
(IIa).

Computed tomography (CT) or magnetic resonance imaging (MRI) may be useful in selected patients presenting with syncope of suspected cardiac etiology(IIb).

Routine cardiac imaging is not useful in the evaluation of patients with syncope unless cardiac etiology is suspected on the basis of an initial evaluation, including history, physical examination, or ECG (III).

3.2.2. Stress Testing: Recommendation

Exercise stress testing can be useful to establish the cause of syncope in selected patients who experience syncope or presyncope during exertion (IIa).

3.2.3. Cardiac Monitoring: Recommendations

The choice of a specific cardiac monitor should be determined on the basis of the frequency and nature of syncope events (I).

To evaluate selected ambulatory patients with syncope of suspected arrhythmic etiology, the following external cardiac monitoring approaches can be useful:
1. Holter monitor
2. Transtelephonic monitor
3. External loop recorder
4. Patch recorder
5. Mobile cardiac outpatient telemetry (IIa)

To evaluate selected ambulatory patients with syncope of suspected arrhythmic etiology, an ICM can be useful(IIa).

3.2.4. In-Hospital Telemetry: Recommendation
Continuous ECG monitoring is useful for hospitalized patients admitted for syncope evaluation with suspected cardiac etiology(I).

3.2.5. Electrophysiological Study: Recommendations

EPS can be useful for evaluation of selected patients with syncope of suspected arrhythmic etiology(IIa).

EPS is not recommended for syncope evaluation in patients with a normal ECG and normal cardiac structure and function, unless an arrhythmic etiology is suspected (III).

3.2.6. Tilt-Table Testing: Recommendations

If the diagnosis is unclear after initial evaluation, tilt-table testing can be useful for patients with suspected VVS(IIa).

Tilt-table testing can be useful for patients with syncope and suspected delayed OH when initial evaluation is not diagnostic(IIa).

Tilt-table testing is reasonable to distinguish convulsive syncope from epilepsy in selected patients(IIa).

Tilt-table testing is reasonable to establish a diagnosis of pseudosyncope (IIa).

Tilt-table testing is not recommended to predict a treatments response to medical for VVS (III).

3.3. Neurological Testing

3.3.1. Autonomic Evaluation: Recommendation

Referral for autonomic evaluation can be useful to improve diagnostic and prognostic accuracy in selected patients with syncope and known or suspected neurodegenerative disease (IIa).

3.3.2. Neurological and Imaging Diagnostics: Recommendations

Simultaneous monitoring of an EEG and hemodynamic parameters during tilt-table testing can be useful to distinguish among syncope, pseudosyncope,and epilepsy (IIa).

MRI and CT of the head are not recommended in the routine evaluation of patients with syncope in the absence of focal neurological findings or head injury that support further evaluation (III).

Carotid artery imaging is not recommended in the routine evaluation of patients with syncope in the absence of focal neurological findings that support further evaluation (III).

Routine recording of an EEG is not recommended in the evaluation of patients with syncope in the absence of specific neurological features suggestive of a seizure (III).