Isoproterenol Causing Coronary Vasospasm and ST Elevations During Tilt Table Testing

Area of Science:

• Cardiology
• Neurology
• Clinical Medicine

Background:

• Syncope, a transient loss of consciousness due to reduced cerebral perfusion, encompasses reflex syncope (vasovagal, carotid sinus syndrome, situational).
• Vasovagal syncope, the most common type, is often triggered by emotional stress or prolonged standing and diagnosed via tilt table testing.
• Thorough syncope investigation is crucial as underlying cardiovascular disorders can be serious.

Observation:

• A 48-year-old previously healthy woman underwent a tilt table test augmented with isoproterenol.
• During the test, she exhibited inferior wall ST elevations, an electrocardiographic change typically indicating myocardial ischemia.
• This presentation is unusual for standard vasovagal syncope diagnosis.

Findings:

• The observed ST elevations during the tilt table test were attributed to vasovagal syncope.
• These findings suggest a concurrent or related event of right coronary artery vasospasm.
• Isoproterenol augmentation may unmask or precipitate coronary vasospasm in susceptible individuals.

Implications:

• This case underscores the importance of recognizing potential cardiac manifestations during syncope evaluation.
• It suggests that vasovagal syncope, particularly when pharmacologically provoked, may be associated with coronary artery vasospasm.
• Clinicians should consider vasospastic phenomena in the differential diagnosis of syncope with ischemic changes on ECG during provocative testing.