Tilt table test
Encyclopedia
A tilt table test, occasionally called upright tilt testing, is a medical procedure
often used to diagnose
dysautonomia
or syncope
. Patient
s with symptom
s of dizziness or lightheadedness, with or without a loss of consciousness
(fainting), suspected to be associated with a drop in blood pressure
or positional tachycardia
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 while connected to ECG and blood pressure monitors. The table then creates a change in posture from lying to standing.
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 may be placed in case the patient needs to be given medication
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 using mean flow velocity recording with transcranial doppler
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.
s. Sometimes, the patient will be given a drug, such as glyceryl trinitrate or isoproterenol
, 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).
A common side effect during tilt table testing is a feeling of heaviness and warmth in the lower extremities. This is due to blood
pooling in the legs and, to onlookers, the patient's lower extremities may appear blotchy, pink
, or red
.
Dizziness or lightheadedness are also likely to occur in susceptible patients. Tilt table testing could provoke fainting or syncope
; in fact, this is the purpose of the test. It may not be appropriate, or indeed even possible, to stop the test before this 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.
In extreme cases, tilt table testing could provoke seizures or even cause the heart to stop
. The heart resumes beating normally upon being returned to a flat or head-down position.
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
or adrenaline.
Head-up tilt table testing can be used to evaluate autonomic dysfunction and is frequently helpful for the work-up of fibromyalgia (FM) complaints, including fatigue, dizziness, and palpitations. One of the most common events experienced by FM patients during tilt table testing is postural orthostatic tachycardia syndrome (POTS) which is defined as a heart rate increase of more than 30 beats per minute after more than three minutes of standing upright.
In a study of adolescents, chronic fatigue syndrome
(CFS) subjects were more susceptible to orthostatic intolerance (OI) than controls, the cardiovascular response predominantly manifest as POTS without hypotension, a response unique to CFS suggesting further investigation is warranted with respect to the pathophysiologic mechanisms involved.
It has recently shown that CFS is associated with a short corrected electrocardiographic QT interval (QTc). A relatively short QTc and positive HIS distinguish CFS patients from FM patients. These data may support the contention that FM and CFS are separate disorders.
The head-up tilt table test reveals a particular dysautonomia in CFS patients that differs from other conditions and is useful in supporting the diagnosis of CFS. Furthermore, these studies indicate that the test is an objective means of monitoring the course and management of CFS.
Medical procedure
A medical procedure is a course of action intended to achieve a result in the care of persons with health problems.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
Diagnosis is the identification of the nature and cause of anything. Diagnosis is used in many different disciplines with variations in the use of logics, analytics, and experience to determine the cause and effect relationships...
dysautonomia
Dysautonomia
Dysautonomia is a broad term that describes any disease or malfunction of the autonomic nervous system. This includes postural orthostatic tachycardia syndrome , inappropriate sinus tachycardia , vasovagal syncope, mitral valve prolapse dysautonomia, pure autonomic failure, neurocardiogenic...
or syncope
Syncope (medicine)
Syncope , the medical term for fainting, is precisely defined as a transient loss of consciousness and postural tone characterized by rapid onset, short duration, and spontaneous recovery due to global cerebral hypoperfusion that most often results from hypotension.Many forms of syncope are...
. Patient
Patient
A patient is any recipient of healthcare services. The patient is most often ill or injured and in need of treatment by a physician, advanced practice registered nurse, veterinarian, or other health care provider....
s with symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
s of dizziness or lightheadedness, with or without a loss of consciousness
Consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
(fainting), suspected to be associated with a drop in blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
or positional tachycardia
Tachycardia
Tachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
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 while connected to ECG and blood pressure monitors. The table then creates a change in posture from lying to standing.
Preparations
Before taking the test, the patient may be instructed to fastFasting
Fasting is primarily the act of willingly abstaining from some or all food, drink, or both, for a period of time. An absolute fast is normally defined as abstinence from all food and liquid for a defined period, usually a single day , or several days. Other fasts may be only partially restrictive,...
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 may be placed in case the patient needs to be given medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
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 using mean flow velocity recording with transcranial doppler
Transcranial doppler
Transcranial Doppler is a test that measures the velocity of blood flow through the brain's blood vessels. Used to help in the diagnosis of emboli, stenosis, vasospasm from a subarachnoid hemorrhage , and other problems, this relatively quick and inexpensive test is growing in popularity in the...
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, a patient is suspended at an angle of 60 to 80 degreeDegree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
s. Sometimes, the patient will be given a drug, such as glyceryl trinitrate or isoproterenol
Isoproterenol
Isoprenaline or isoproterenol is a medication used for the treatment of bradycardia , heart block, and rarely for asthma...
, 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. 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 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
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
pooling in the legs and, to onlookers, the patient's lower extremities may appear blotchy, pink
Pink
Pink is a mixture of red and white. Commonly used for Valentine's Day and Easter, pink is sometimes referred to as "the color of love." The use of the word for the color known today as pink was first recorded in the late 17th century....
, or red
Red
Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...
.
Dizziness or lightheadedness are also likely to occur in susceptible patients. Tilt table testing could provoke fainting or syncope
Collapse (medical)
Collapse is a sudden and often unannounced loss of postural tone , often but not necessarily accompanied by loss of consciousness.If the episode was accompanied by a loss of consciousness, the term syncope is used. The main causes are cardiac , seizures or a psychological cause...
; in fact, this is the purpose of the test. It may not be appropriate, or indeed even possible, to stop the test before this 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.
In extreme cases, tilt table testing could provoke seizures or even cause the heart to stop
Asystole
In medicine, asystole is a state of no cardiac electrical activity, hence no contractions of the myocardium and no cardiac output or blood flow...
. The heart resumes beating normally upon being returned to a flat or head-down position.
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
Atropine is a naturally occurring tropane alkaloid extracted from deadly nightshade , Jimson weed , mandrake and other plants of the family Solanaceae. It is a secondary metabolite of these plants and serves as a drug with a wide variety of effects...
or adrenaline.
Applications
These findings suggest a positive induced cardiovascular training effect in the fighter pilots group. Repetitive exposure to higher G forces results in an increased resting mean arterial pressure and an elevated heart rate response to tilt table tests, which may provide benefits to operational fighter pilots.Head-up tilt table testing can be used to evaluate autonomic dysfunction and is frequently helpful for the work-up of fibromyalgia (FM) complaints, including fatigue, dizziness, and palpitations. One of the most common events experienced by FM patients during tilt table testing is postural orthostatic tachycardia syndrome (POTS) which is defined as a heart rate increase of more than 30 beats per minute after more than three minutes of standing upright.
In a study of adolescents, chronic fatigue syndrome
Chronic fatigue syndrome
Chronic fatigue syndrome is the most common name used to designate a significantly debilitating medical disorder or group of disorders generally defined by persistent fatigue accompanied by other specific symptoms for a minimum of six months, not due to ongoing exertion, not substantially...
(CFS) subjects were more susceptible to orthostatic intolerance (OI) than controls, the cardiovascular response predominantly manifest as POTS without hypotension, a response unique to CFS suggesting further investigation is warranted with respect to the pathophysiologic mechanisms involved.
It has recently shown that CFS is associated with a short corrected electrocardiographic QT interval (QTc). A relatively short QTc and positive HIS distinguish CFS patients from FM patients. These data may support the contention that FM and CFS are separate disorders.
The head-up tilt table test reveals a particular dysautonomia in CFS patients that differs from other conditions and is useful in supporting the diagnosis of CFS. Furthermore, these studies indicate that the test is an objective means of monitoring the course and management of CFS.