Tilt table test

The tilt table testing is an investigation in human medicine. It allows the evaluation of the adaptation of blood pressure to passive changes in position of the patient and orthostatic hypotension (lack of adaptation of blood pressure on rapid changes in position ) or vasovagal syncope clarify (fainting about after an extended period in an upright position) as a cause of repeated loss of consciousness ( syncope). Cause orthostatic dysregulation may be a faulty control of the heart, blood vessels or the loss of function of the autonomic nervous system.

Indication

Syncope are frequent events in the general population. In older people, the incidence is 6% per year, 1/ 3 of them suffer more syncopation in a row. The risks and consequences of resulting in serious injury are evident.

A comprehensive diagnostics enables up to 70% of cases to clarify the cause of syncope. For some causes of action can influence the morbidity and mortality favorably against a recurrence. A tilt table testing is carried out as a rule, if the previous investigation such as echocardiography, exercise test, ambulatory blood pressure monitoring, Holter monitoring, and simple circuit tests have yielded inconclusive.

The tilt table testing may reveal for the classification of syncope result without this necessarily trigger.

Implementation

The principle of the tilt table is based on, to understand the pathogenic mechanisms that have led to the experienced syncope under controlled conditions. The secured on a special examination table patient is slowly " tilts " to from the horizontal beds to 60-70 °, where it a " sink " of blood in the lower extremities is ( venous pooling). This is the heart less blood is available, the stroke volume decreases and it comes to blood pressure. In order to judge it provoked compensatory mechanisms, blood pressure and heart rate are regularly determined during the experiment. On the basis of the distinction can be made between normal and pathological circulatory reaction and in some patients allows for specific treatment of any circulatory reaction weaknesses. Is that enough " tipping " is not sufficient to trigger a cycle of stress, a pharmacological provocation can also be performed with nitroglycerin ( "Italian protocol ").

In healthy subjects, there comes after the " tipping " to a brief drop in blood pressure, which pulls on the activation of baroreceptors a narrowing of the vessels and an increase in heart rate after themselves. If this reaction is disturbed, the blood pressure is not adequately compensated and it comes to unconsciousness ( positive test result ). From a secondary dysregulation or neurally mediated dysregulation occurs when the compensation mechanism was initially successful, but it comes at a delayed fall in blood pressure. Further distinction is made in a kardioinhibitorischen type, drop in blood pressure and heart rate, and a vasodepressor type in which the heart rate remains unaffected.

For a positive test result, it may be several causes. To understand whether a slump in blood pressure or heart rate has led to loss of consciousness, in more modern implementation procedures of the blood pressure is measured continuously during the experiment. If this data is logged, the test can be aborted already positive during presyncope. In this way, syncope, thereby forming composite potential complications can be avoided.

Complications

Overall, the tilt table is very safe. There are no reports of deaths from the study. The occurrence of syncope is considered a positive test result and not as a complication. It may, depending on the type of dysregulation, come to a sharp drop in heart rate up to the self-limiting asystole. Under pharmacological provocation may occur in rare cases to more side effects.