Definisi Hipotensi Orthostatik adalah apabila terjadi penurunan tekanan darah sistolik 20mmHg atau tekanan darah diastolik 10mmHg pada posisi berdiri selama 3menit. Pada saat seseorang dalam posisi berdiri sejumlah darah 500-800 ml darah akan berpindahke abdomen daneksremitas bawah sehingga terjadi penurunan besar volume darah balik vena secaratiba-tiba kejantung. Penurunan ini mencetuskan peningkatan refleks simpatis. Kondisi ini dapat asimptomatik tetapi dapat pula menimbulkan gejala seperti kepala terasaringan, pusing, gangguan penglihatan, lemah, berbedebar-debar, hinggasinkop. Sinkop yang terjadi setelah makan terutama pada usia lanjut disebabkan oleh retribusi darah k eusus.
Hipotensiortostatikmerupakanpenurunantekanandarahseseorangsedangdalamposisitegak. Keadaaniniterjadiberbagaikeadaaan:
a. Hipovolemia (perdarahan, muntah, diare,diuretik).
b. Gangguanpada reflex normal (nitrat, vasodilator, penghambatkanalkalium, neuroleptik).
c. Kegagalanautonom. Primer atausekunder. Diabetes paling sering menyebabkan neuropatiotonom sekunder, sedangkan usia lanjut merupakan penyebab lazim kegagalanotonom primer. Paling tidak telah dicerminkan oleh tigasindroma
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| Definisi Hipotensi Orthostatik |
Disautonomiaakutatausubakut
Padapenyakitini, seorang dewasa atau anak yang tampak sehat mengalami palisisparsialatau total pada system saraf parasimpatis dan simpatis selama beberapa hari atau beberapa minggu. Refleks pupil menghilang sebagaimanahalnya dengan fungsi lakrimasi, saliva sertaperspirasi, danter dapat impotensi, paresis otot-ototkandung kemih dan usus serta hipotensi ortostatik. Penyakit tersebut dianggap merupakan suatu varian dari polyneuritis idiopatikakut yang ada hubungannya dengan sindromaGuillain-Bard. Kesembuhan mungkin dapat dipercepat dengan prednisone.
Insufisiensiautonompascanglionikkronis
Keadaan ini merupakan penyakit yang menyerang usia pertengahan dan usia lanjut. Penderita berangsur-angsur mengalami hipotensi ortostatik kronik yang kadang-kadangbersamaan dengan gejala impotensi dangang guansfingter. Gejala pucat atau mual. Lakil-laki lebih sering terkena, tampaknya ireversibel.
Insufisiensiautonompraganglionikkronis
Padakeadaan ini, gejala hipotensi ortostatik dengan anhidrosis yang bervariasi, impotensi dan gangguan sfingter terjadi bersama dengan kelainan yang mengenal system saraf pusat. Kelainan tersebut mencakup (1) tremor, rigiditasekstrapiramidal serta akinesia (sindroma Shy-Drager), (2) degenerasi serebelum progressive yang pada sebagian kasus bersifat familial dan (3) kelainan sereberal serta ekstrapiramidal yang lebih bervariasi (degenerasistriatonigra).
There are three main ways to identify the causes of syncope: the medical history, the physical examination, and cardiac testing. A medical history and physical examination are recommended for anyone who has had syncope. Some people will also require cardiac testing.
Medical history — Gathering as much information as possible about events that occurred before, during, and after a syncopal episode can be helpful in determining the possible cause of syncope.
As an example, vasovagal syncope is suspected in a person who has warning signs of nausea or sweating. In contrast, a sudden loss of consciousness with no warning is more likely to be due to a heart rhythm problem. A person who has syncope during exertion is more likely to have an obstruction to blood flow (aortic stenosis or hypertrophic cardiomyopathy) or ventricular tachycardia as a cause.
Information about current medications and pre-existing medical conditions such as diabetes, heart disease, or psychiatric illness can help pinpoint the cause of syncope. If the person has abnormal body movements while unconscious and requires a long time to recover consciousness, the person may have had a seizure and not a true syncopal episode.
Physical examination — The clinician will measure your heart rate and blood pressure to help determine if a rhythm disturbance or low blood pressure caused the syncope. You may be asked to sit or stand while the blood pressure is measured to test for orthostatic hypotension. The clinician will listen to your heart for abnormal sounds that can be present in conditions such as aortic stenosis. You may have a test for blood in the stool to evaluate for blood loss, which could result in syncopal episodes.
If the cause of the syncope is not readily apparent, the clinician may perform special maneuvers to test your response. As an example, you may be asked to bear down as if having a bowel movement; abnormal heart sounds that occur in response to this maneuver can point to hypertrophic cardiomyopathy. The clinician may firmly massage your carotid artery (located in the neck) while your heart rate is closely monitored with an electrocardiogram (ECG or EKG). The heart's response to this maneuver can give clues to a possible diagnosis.
Testing — A number of medical tests are available to help determine the cause of the syncope. However, testing is not always required.
Electrocardiogram — Most patients who have had an episode of syncope will have an ECG. An ECG can be performed in a clinician's office and takes only a few minutes. Sticky pads are placed on your chest, abdomen, arm, and leg, and are connected to a recording device with long, thin cables. This is not painful and there is no risk of electric shock with an ECG.
The ECG provides a picture of the electrical activity passing through the heart muscle. A normal ECG does not necessarily mean that syncope is not caused by a heart rhythm problem. Heart rhythm problems are often brief, come and go, and may not be present at the moment when the ECG is performed.
Rhythm monitoring — Heart rhythm monitoring may be recommended to diagnose rhythm problems that come and go and have not been detected with a routine ECG. This monitoring may be done at home or in the hospital.
●Holter monitor – You may be asked to wear a monitoring device, called a Holter monitor, for 24 or 48 hours while performing normal daily activities at home. The device is connected to several long thin cables that are attached to your chest with sticky pads (similar to an ECG). The cables connect to a small, portable machine that can be attached to a belt or strap that is carried over the shoulder (figure 3).
However, this type of monitoring has limited use and provides a diagnosis in only about 2 to 3 percent of people with syncope. If you do not experience a syncopal episode while wearing the Holter monitor, the test may need to be repeated, or an alternate form of long-term monitoring may be recommended.
●Event recorder – An event recorder may be recommended to capture rhythm problems associated with a syncopal episode. The advantages of an event recorder compared to a Holter monitor are its small size and the ability to monitor for abnormal rhythms for longer periods of time (usually one to two months).
Some devices require you to activate the recorder when you feel symptoms of a syncopal episode. However, if you lose consciousness and another person is not available to assist with the recording, the opportunity to "capture" the event on the monitor may be lost (figure 4).
●Intermittent loop recorders – Intermittent loop recorders were developed to capture rhythm problems that occur before the device is activated. When you activate the monitoring device after regaining consciousness, the ECG recordings from the previous few minutes are retrieved and stored for analysis at a later time.
An implantable loop recorder (ILR) provides a way to monitor rhythms over an extended period of time (eg, 18 to 24 months). The ILR is implanted under the skin on the upper left chest area. It stores events automatically according to programmed criteria, or can be activated by the patient. The ILR may be most useful if your symptoms are infrequent and an arrhythmia is suspected, but other forms of testing are negative or inconclusive.
Echocardiogram — An echocardiogram is useful for identifying underlying structural heart disease such as hypertrophic cardiomyopathy or significant aortic stenosis. These findings alone do not conclusively establish the specific cause for syncope.
An echocardiogram uses ultrasound (sound waves) to obtain detailed pictures of your heart as it beats. A technician presses a transducer (wand) against your chest and abdomen. The transducer is attached to a recording device and monitor. You are awake during the procedure. An echocardiogram does not use radiation.
Upright tilt table test — This test is often done in healthy patients who have syncope. You lie on a flat table and are tilted at various angles while your heart rate and blood pressure are monitored closely (figure 5). Your response to the change in position can sometimes give clues about the cause of syncope.
Electrophysiology study — An electrophysiology study (EPS) may be performed if you have heart disease or if a rhythm problem is suspected.
Most people undergo EPS in a hospital setting. You will be given a sedative before the procedure but may be awake during testing. The physician uses a local anesthetic to numb a small area over a blood vessel, usually in the groin, and then threads small wires through the blood vessels into the heart using x-ray (fluoroscopic) guidance. Once in the heart, precise measurements of the heart's electrical function can be obtained.
Exercise testing — In some people, especially those with a history of syncope during exertion, an exercise test is useful. Your blood pressure, heart rate, and rhythm are monitored while exercising on a treadmill or bicycle.
Electroencephalogram — An electroencephalogram (EEG) involves the measurement of electrical activity in the brain. It can be performed in a provider's office or in a hospital, and generally takes about one hour. Multiple electrodes (small, flat metal discs) will be attached to your head and face with a sticky paste. The electrodes are connected to a recording device with long, thin wires. You must lie still and avoid speaking during the test.
An EEG is frequently obtained in people with syncope, but is rarely useful. It can be helpful if you have syncope and seizure-like activity.
