WHEN SHOULD WE USE TILT TESTING?

Dr Michele Brignole states that, although management guided by clinical history is often considered superior to tilt table testing (TTT) for identifying patients affected by reflex syncope, the latest ESC guidelines on syncope² detail its appropriate indications and the correct way to interpret results.

Brignole cites the ESC 2009 Guidelines for the management of syncope as:

1.  Offering precise criteria based on clinical presentation for diagnosis of reflex syncope:

a) Vasovagal syncope can be diagnosed if syncope is precipitated by emotional distress (from fear, pain, instrumentation, venipuncture).

b) Situational syncope can be diagnosed if syncope is triggered by specific circumstances (during or immediately after micturition, defecation, coughing, swallowing, laughing, eating or immediately after vigorous exercise) or by prolonged standing.

2.  Providing criteria for risk stratification and, specifically, for identification of patients with suspected cardiac syncope. In these patients, it is cardiac evaluation that is warranted. TTT, however, should not be performed as a first-choice test.

3.  Defining a syndrome of delayed orthostatic hypotension in which the standard active standing test is negative and diagnosis can be made only by means of TTT.

The latest ESC guidelines also offer general indications for the proper use of tilt table testing, says Brignole:

When NOT to tilt-table test

• When diagnosis of vasovagal syncope is already certain
• When a cardiac syncope is likely (“cardiac evaluation first”)
• When syncope occurs in absence of emotional distress or orthostatic stress
• When a diagnosis is not necessary

When to tilt-table test – in establishing a diagnosis

• When reflex syncope is suspected, but clinical presentation is atypical
• When syncope is unexplained and an orthostatic trigger is present
• When delayed orthostatic hypotension is suspected

When to tilt-table test – in establishing therapy

• When differentiating reflex syncope from orthostatic hypotension as prerequisite for a specific therapy

• To demonstrate susceptibility of the patient to reflex syncope as part of the biofeedback training program for counter-pressure maneuvers. With this indication, a positivity rate approaching 100% is desirable. Nitroglycerin TTT should be performed in patients in whom a situational trigger is present, whereas clomipramine TTT should be undertaken in patients in whom an emotional trigger is present

A distinct form of syncope, defined by idiopathic paroxysmal atrioventricular (AV) block, was proposed by a study³ published recently in the Journal of the American College of Cardiology.  18 patients presenting with unexplained syncope underwent a full cardiological work-up, competed by means of TTT.  The authors hypothesise a new syndrome of syncope due to idiopathic paroxysmal AV block prevalent among patients without structural heart disease and with a normal electrocardiogram.

References

1 Brignole M. When to use tilt table testing and findings regarding its sensitivity.  The e-journal of the ESC Council for Cardiology Practice 2011;9:  Available from http://www.escardio.org/communities/councils/ccp/e-journal/volume9/Pages/tilt-table-testing-when-to-perform-specificity-brignole-michele.aspx

2 Moya A, Sutton R, Ammirati F, et al. Guidelines for the Diagnosis and Management of Syncope (Version 2009). Eur Heart J 2009;30:2631–71.

3 Brignole M, Deharo JC, De Roy L, et al. Syncope due to idiopathic paroxysmal atrioventricular block long-term follow-up of a distinct form of atrioventricular block. JACC 2011;58:000-0. doi:10.1016/j.jacc.2010.12.045