A tilt table test (TTT), occasionally called upright tilt testing (UTT), is a

medical procedure A medical procedure is a course of action intended to achieve a result in the delivery of healthcare. A medical procedure with the intention of determining, measuring, or diagnosing a patient condition or parameter is also called a medical test. ...

often used to

diagnose Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems enginee ...

dysautonomia Dysautonomia or autonomic dysfunction is a condition in which the autonomic nervous system (ANS) does not work properly. This may affect the functioning of the heart, bladder, intestines, sweat glands, pupils, and blood vessels. Dysautonomia has m ...

or syncope.

Patient A patient is any recipient of health care services that are performed by healthcare professionals. The patient is most often ill or injured and in need of treatment by a physician, nurse, optometrist, dentist, veterinarian, or other health c ...

s with

symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

s of dizziness or lightheadedness, with or without a loss of

consciousness Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scien ...

(

fainting Syncope, commonly known as fainting, or passing out, is a loss of consciousness and muscle strength characterized by a fast onset, short duration, and spontaneous recovery. It is caused by a decrease in blood flow to the brain, typically from ...

), suspected to be associated with a drop in

blood pressure Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" r ...

or positional

tachycardia Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal (su ...

are good candidates for this test. The procedure tests for causes of syncope by attempting to cause syncope by having the patient lie flat on a special table or bed and then be monitored with

ECG Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the hear ...

and a blood pressure monitor that measure continuous, beat to beat, non-invasively. The table then creates a change in posture from lying to standing.

Preparations

Before taking the test, the patient may be instructed to fast for a period before the test will take place and to stop taking any medications. On the day of the tilt table test, an

intravenous line Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrie ...

may be placed in case the patient needs to be given

medications A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and rel ...

quickly; however, this may influence the results of the test and may only be indicated in particular circumstances. More recently, most investigators monitor

cerebral perfusion pressure Cerebral perfusion pressure, or CPP, is the net pressure gradient causing cerebral blood flow to the brain (brain perfusion). It must be maintained within narrow limits because too little pressure could cause brain tissue to become ischemic (having ...

using mean flow velocity recording with

transcranial Doppler Transcranial Doppler (TCD) and transcranial color Doppler (TCCD) are types of Doppler ultrasonography that measure the velocity of blood flow through the brain's blood vessels by measuring the echoes of ultrasound waves moving transcranially (thr ...

ultrasound in supine horizontal position, during and after head-up tilt. An 18 MHz ultrasound transducer is placed on the temporal bone above the cheekbone, using headgear to hold the probe in place.

Procedure

A tilt table test can be done in different ways and be modified for individual circumstances. In some cases, the patient will be strapped to a tilt table lying flat and then tilted or suspended completely or almost completely upright (as if standing). Most of the time, the patient is suspended at an angle of 60 to 80

degree Degree may refer to: As a unit of measurement * Degree (angle), a unit of angle measurement ** Degree of geographical latitude ** Degree of geographical longitude * Degree symbol (°), a notation used in science, engineering, and mathematics ...

s. Sometimes, the patient will be given a drug, such as

glyceryl trinitrate Nitroglycerin (NG), (alternative spelling of nitroglycerine) also known as trinitroglycerin (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless, oily, explosive liquid most commonly produced by nitrating ...

(nitroglycerin) or

isoproterenol Isoprenaline, or isoproterenol (brand name: Isoprenaline Macure), is a medication used for the treatment of bradycardia (slow heart rate), heart block, and rarely for asthma. It is a non-selective β adrenoceptor agonist that is the isopropylam ...

, to create further susceptibility to the test. In all cases, the patient is instructed not to move. Symptoms, blood pressure, pulse, electrocardiogram, and sometimes blood oxygen saturation are recorded. The test either ends when the patient faints or develops other significant symptoms, or after a set period (usually from 20 to 45 minutes, depending on the facility or individualized protocol).

Diagnostic symptoms

A tilt table test is considered positive if the patient experiences symptoms associated with a drop in blood pressure or

cardiac arrhythmia Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adults ...

. A normal person's blood pressure will not drop dramatically while standing, because the body will compensate for this posture with a slight increase in heart rate and constriction of the

blood vessels The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away f ...

in the legs. If this process does not function normally in the patient, the test could provoke signs and symptoms ranging from minor lightheadedness to a very severe cardiac episode, depending on the person. A common side effect during tilt table testing is a feeling of heaviness and warmth in the lower extremities. This is due to

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...

pooling in the legs and, to onlookers, the patient's lower extremities may appear blotchy,

pink Pink is the color of a namesake flower that is a pale tint of red. It was first used as a color name in the late 17th century. According to surveys in Europe and the United States, pink is the color most often associated with charm, politeness, ...

, or

red Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondar ...

. Dizziness or lightheadedness are also likely to occur in susceptible patients. Tilt table testing could provoke fainting or syncope. It is the purpose of the test to provoke these symptoms, in order to aid in diagnosis. It may not be appropriate, or indeed even possible, to stop the test before fainting occurs, as the drop in blood pressure or pulse rate associated with fainting can come on in seconds. This is why the patient's blood pressure and ECG should be continuously monitored during the test. If at any time in tilt table testing a patient loses consciousness, he or she will be returned to a supine or head down position and will be given immediate medical attention, which could include being given fluids or perhaps

atropine Atropine is a tropane alkaloid and anticholinergic medication used to treat certain types of nerve agent and pesticide poisonings as well as some types of slow heart rate, and to decrease saliva production during surgery. It is typically given i ...

or a sympathomimetic drug like epinephrine or

ephedrine Ephedrine is a central nervous system (CNS) stimulant that is often used to prevent low blood pressure during anesthesia. It has also been used for asthma, narcolepsy, and obesity but is not the preferred treatment. It is of unclear benefit in ...

which will raise blood pressure and heart rate rapidly. In extreme cases, tilt table testing could provoke

seizures An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or neural oscillation, synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much o ...

or even cause the heart to stop. The heart resumes beating normally upon being returned to a flat or head-down position. A drop in blood pressure during the tilt table test is indicative of

orthostatic hypotension Orthostatic hypotension, also known as postural hypotension, is a medical condition wherein a person's blood pressure drops when standing up or sitting down. Primary orthostatic hypertension is also often referred to as neurogenic orthostatic hyp ...

. A marked increase in heart rate in the absence of orthostatic hypotension is indicative of

postural orthostatic tachycardia syndrome Postural orthostatic tachycardia syndrome (POTS) is a condition characterized by an abnormally large increase in heart rate upon standing. Symptoms may include lightheadedness, brain fog, blurred vision, weakness, fatigue, headaches, heart ...

References

External links

2004 European Society of Cardiology Guidelines on Management (Diagnosis and Treatment) of Syncope.
{{Peripheral nervous system tests and procedures Diagnostic cardiology Diagnostic neurology Physical examination

Preparations

Procedure

Diagnostic symptoms

See also

References

External links