Is presyncope (near fainting) the same as near syncope (near fainting)?

Presyncope and Near Syncope: Understanding the Relationship

Yes, presyncope and near syncope are the same condition, both referring to symptoms that precede potential syncope but without actual loss of consciousness. 1

Definition and Characteristics

Presyncope (or near syncope) is defined as:

• The sudden onset of symptoms that resemble the prodrome of syncope but are not followed by loss of consciousness 1
• A condition where patients feel as though syncope is imminent 1
• Symptoms include light-headedness, dizziness, nausea, sweating, weakness, and visual disturbances (such as "tunnel vision" or blurred vision) 1
• Observable signs include pallor/paleness, sweating, vomiting, shivering, diminished postural tone, and confusion 1

Clinical Significance

Despite the absence of actual loss of consciousness, presyncope should be taken seriously:

• Multiple prospective studies have shown that short-term serious outcomes and deaths in patients with syncope and presyncope are extremely similar 1
• The prevalence of short-term serious outcomes varies from 4% to 27% among emergency department patients with presyncope 2
• Arrhythmia is the most common serious outcome, followed by anemia/hemorrhage 2
• Emergency physicians have difficulty predicting which presyncope patients are at risk for serious outcomes after ED discharge 3

Management Approach

The management of presyncope should mirror that of syncope 1:

1. Immediate actions:

   • Maintain or assume a safe position (sitting or lying down) 1
   • Use physical counterpressure maneuvers (PCMs) to avoid progression to syncope 1

2. PCM techniques:

   • Lower-body PCMs (leg crossing with tensing, squatting) are preferable to upper-body maneuvers 1
   • Other effective PCMs include handgrip, arm tensing, and abdominal muscle tensing 1
   • PCMs should NOT be used when symptoms of heart attack or stroke accompany presyncope 1

3. Risk stratification:

   • High-risk patients with cardiovascular or structural heart disease, history concerning for arrhythmia, abnormal ECG findings, or severe comorbidities should be admitted to the hospital 4
   • Low-risk patients with a single episode may be reassured with minimal further investigation 4

Important Distinctions

• While presyncope and near syncope are synonymous, they must be distinguished from actual syncope, which involves complete loss of consciousness 1
• Both conditions fall under the broader category of transient loss of consciousness (T-LOC) disorders, though presyncope does not involve actual loss of consciousness 1
• Presyncope symptoms can be relatively non-specific and may overlap with the premonitory phase of true syncope 1

Common Pitfalls to Avoid

1. Diagnostic confusion: Presyncope symptoms can be mistaken for other conditions like vertigo, anxiety, or hypoglycemia

2. Underestimating risk: Despite no loss of consciousness, presyncope carries similar risks to syncope and requires the same level of caution 2

3. Inadequate evaluation: Focusing only on symptoms without investigating potential underlying causes can miss serious conditions

4. Overlooking cardiac causes: While neurally mediated (vasovagal) presyncope is common and benign, cardiac causes require urgent attention 4

By understanding that presyncope and near syncope are identical conditions with potentially serious implications, clinicians can provide appropriate evaluation and management to prevent progression to syncope and identify underlying pathology.