Syncope: First Evaluation and Management in the Emergency Department

Fig. 2.1

Context of transient loss of consciousness. SCD sudden cardiac death, TLOC transient loss of consciousness

Table 2.1

Conditions incorrectly diagnosed as syncope

Disorders with partial or complete LOC (without global cerebral hypoperfusion)

Epilepsy

Metabolic disorders including hypoglycemia, hypoxia, hyperventilation with hypocapnia

Intoxication

Vertebrobasilar TIA

Disorders without impairment of consciousness

Cataplexy

Drop attacks

Falls

Functional (psychogenic pseudosyncope)

TIA of carotid origin

LOC loss of consciousness, TIA transient ischemic attack

Table 2.2

Classification of syncope

Neurally mediated syncope

Vasovagal cause

Mediated by emotional distress (fear, pain, instrumentation blood phobia)

Orthostatic stress

Situational

Sneeze, cough

Gastrointestinal stimulation (defecation, abdominal pain, swallowing)

After micturition

After exercise

Postprandial

Others

Carotid sinus syncope

Forms without apparent triggers or atypical presentation

Orthostatic hypotension syncope

Primary autonomic failure

Pure autonomic failure, multiple atrophy, Parkinson disease with autonomic failure

Lewy body dementia

Secondary autonomic failure

Diabetes, amyloidosis, uremia, spinal injuries

Drug-induced orthostatic hypotension

Alcohol, vasodilators, diuretics, antidepressants

Volume depletion

Hemorrhage, diarrhea, vomiting, etc

Cardiovascular syncope

Arrhythmia as primary cause

Bradycardia: sinus node dysfunction, AV conduction system disease, implanted device dysfunction

Tachycardia: supraventricular, ventricular

Drug-induced bradycardia and arrhythmias

Structural disease

Cardiac: valvular diseases, AMI, hypertrophic cardiomyopathy, etc

Others: acute aortic dissection, pulmonary hypertension, pulmonary embolus

This syncope often raises diagnostic and therapeutic problems which is proved by the diversity of the pathways followed by patients attending the ED. Indeed, data from the literature [4–7] reveal that these patients may be hospitalized in cardiology, neurology, pediatric, geriatric, internal medicine, and orthopedic wards. These patients then undergo, often inappropriately, several instrumental examinations that are costly and have a low diagnostic yield. The result is that hospitalization is prolonged and healthcare costs rise, while a correct diagnosis of the cause of syncope fails to be reached in a high percentage of cases. As the risk of malpractice suits is high in this field, ED physicians often adopt a strategy of “self-defense,” which results in an increase of the number of hospitalizations and inappropriate instrumental investigations. Thus, the current management of syncope displays little diagnostic efficacy and considerable economic inefficiency.

The factors underlying these disappointing results can be summed up as follows: insufficient competence and attention on the part of physicians with regard to the differential diagnosis of TLOC, owing to the difficulty of tackling this problem in a multidisciplinary manner; a “defensive” stance prompted by the possible legal implications of a wrong diagnosis; and, in various healthcare institutions, the lack of diagnostic and therapeutic facilities specialized in the management of syncope patients [11, 12].

2.2.2 The Recommended Management of Syncope in the ED

Most of the direct cost of syncope is attributable to hospitalization. A proper diagnostic evaluation and prognostic stratification of syncope in the ED should limit hospitalization to patients suffering from heart disease, serious neurological diseases, or severe secondary traumas.

In 2009 the European Society of Cardiology developed guidelines on the management of syncope [10]. This document defined what has become the current standard for the management of patients with TLOC and the most valuable diagnostic pathway, and gave recommendations on indications and interpretation of diagnostic tests with indications for hospitalization and treatment.

According to the guidelines, the cornerstone in syncope management in the ED is the initial clinical evaluation, i.e., history, physical examination, recumbent and orthostatic blood pressure measurement, and electrocardiogram (ECG).

Patients should be interrogated about:

The circumstances (position and activity of the patient, presence of predisposing factors) and symptoms (nausea, dizziness, palpitations) occurring just before the attack
Manner of fall (slumping or kneeling over), duration, and whether movements were present during LOC (if witnessed)
Number, frequency of spells, and age at first episode
Family history of cardiac disease or sudden death, neurological history, metabolic disorders

Consultation by a cardiologist is indicated when a cardiac cause is suspected or ascertained, particularly in cases of:

Presence of definite heart disease, family history of sudden death, or channelopathy
Syncope during exertion or in supine position
Sudden onset of palpitation prior to the syncope

ECG abnormalities such as intraventricular delay with QRS duration >120 ms, Mobitz II second-degree atrioventricular block, sinoatrial pauses >3 s, nonsustained ventricular tachycardia, preexcitation, long or short QT intervals, Brugada pattern, negative precordial T waves suggestive of right ventricular dysplasia, Q waves suggesting previous myocardial infarction, pacemaker/implantable cardioverter-defibrillator malfunction.

Neurological consultation (Fig. 2.2) is indicated for a nonsyncopal TLOC cause (epilepsy, transient ischemic attack, subclavian steal syndrome, psychogenic pseudosyncope), especially in cases of:

Fig. 2.2

Diagnostic flowchart of patients with suspected T-LOC.*May require laboratory investigations. ECG electrocardiographic, TLOC transient loss of consciousness

Presence of aura before the event
Tonic-clonic movements coinciding with the onset of LOC (and not some seconds later) or hemilateral
Clear automatisms or tongue biting
Prolonged confusion after the episode
Family history of seizures, sleepiness or headache after the event

Specific tests such as neurological investigations or blood tests are only indicated for a suspicion of nonsyncopal TLOC.

This strategy requires adequate clinical competence on the part of all of the physicians involved in the management of these patients. Table 2.3 presents the diagnostic criteria that permit a diagnosis of the causes of syncope in the ED by means of initial evaluation, and Table 2.4 lists the clinical features that suggest a diagnosis.

Table 2.3

Diagnostic criteria of causes of syncope with initial evaluation

Vasovagal syncope is diagnosed if syncope is precipitated by emotional distress or orthostatic stress, and is associated with typical prodrome

Situational syncope is diagnosed if syncope occurs during or immediately after specific triggers listed in Table 2.2

Orthostatic syncope is diagnosed when it occurs after standing up and there is documentation of OH

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