Definisi Hipotensi Orthostatikadalahapabilaterjadi penurunantekanandarahsistolik20mmHg atau tekanan darah diastolik 10 mmHg pada posisi berdiri selama 3 menit. Pada saatseseorang dalam posisi berdiri sejumlah darah 500-00 ml darah akan berpindah ke abdomendan eksremitas ba!ah sehingga terjadi penurunan besar "olume darah balik "ena se#ara tiba-tibake jantung. Penurunan ini men#etuskan peningkatan refleks simpatis. $ondisi ini dapatasimptomatik tetapi dapat pula menimbulkan gejala seperti kepala terasa ringan% pusing%gangguanpenglihatan% lemah% berbedebar-debar% hinggasinkop. &inkop'angterjadi setelahmakan terutama pada usia lanjut disebabkan oleh retribusi darah ke usus.Hipotensi ortostatik merupakan penurunan tekanan darah seseorang sedang dalam posisitegak. $eadaan ini terjadi berbagai keadaaan(a. Hipo"olemia )perdarahan% muntah% diare%diuretik*.b. +angguan pada refle, normal )nitrat% "asodilator% penghambat kanal kalium% neuroleptik*.#. $egagalan autonom. Primer atau sekunder. Diabetes paling sering men'ebabkan neuropatiotonomsekunder% sedangkanusialanjut merupakanpen'ebabla-imkegagalanotonomprimer. Paling tidak telah di#erminkan oleh tiga sindroma Disautonomia akut atau subakutPadapen'akitini% seorangde!asaatauanak'angtampaksehatmengalami palisisparsial atau total pada s'stem saraf parasimpatis dan simpatis selama beberapa hariatau beberapa minggu. .efleks pupil menghilang sebagaimana haln'a dengan fungsilakrimasi% sali"asertaperspirasi% danterdapat impotensi% paresisotot-otot kandungkemih dan usus serta hipotensi ortostatik. Pen'akit tersebut dianggap merupakan suatu"arian dari pol'neuritis idiopatik akut 'ang ada hubungann'a dengan sindroma+uillain-/ard. $esembuhan mungkin dapat diper#epat dengan prednisone. 0nsufisiensi autonom pas#anglionik kronis$eadaan ini merupakan pen'akit 'ang men'erang usia pertengahan dan usia lanjut.Penderita berangsur-angsur mengalami hipotensi ortostatik kronik 'ang kadang-kadang bersamaan dengan gejala impotensi dan gangguan sfingter. +ejala pu#at ataumual. 1akil-laki lebih sering terkena% tampakn'a ire"ersibel. 0nsufisiensi autonom praganglionik kronisPada keadaan ini% gejala hipotensi ortostatik dengan anhidrosis 'ang ber"ariasi%impotensi dangangguansfingter terjadi bersamadengankelainan'angmengenals'stem saraf pusat. $elainan tersebut men#akup )1* tremor% rigiditas ekstrapiramidalserta akinesia )sindroma &h'-Drager*% )2* degenerasi serebelum progressi"e 'ang padasebagian kasus bersifat familial dan )3* kelainan sereberal serta ekstrapiramidal 'anglebih ber"ariasi )degenerasi striatonigra*. There are three main ways to identify the causes of syncope: the medical history, the physical examination, and cardiac testing. A medical history and physical examination are recommended for anyone who has had syncope. Some people will also require cardiac testing.Medical history Gathering as much information as possible about eents that occurred before, during,and after a syncopal episode can be helpful in determining the possible cause of syncope.As an example, asoagal syncope is suspected in a person who has warning signs of nausea or sweating. !n contrast, a sudden loss of consciousness with no warning is more li"ely to be due to a heart rhythm problem. A person who has syncope during exertion is more li"ely to hae an obstruction to blood flow #aortic stenosis or hypertrophic cardiomyopathy$ or entricular tachycardia as a cause.!nformation about current medications and pre%existing medical conditions such as diabetes, heart disease, or psychiatric illness can help pinpoint the cause of syncope. !f the person has abnormal body moements while unconscious and requires a long time to recoer consciousness, the person may hae had a sei&ure and not a true syncopal episode.Physical examination The clinician will measure your heart rate and blood pressure to help determineif a rhythm disturbance or low blood pressure caused the syncope. 'ou may be as"ed to sit or stand whilethe blood pressure is measured to test for orthostatic hypotension. The clinician will listen to your heart forabnormal sounds that can be present in conditions such as aortic stenosis. 'ou may hae a test for blood in the stool to ealuate for blood loss, which could result in syncopal episodes.!f the cause of the syncope is not readily apparent, the clinician may perform special maneuers to test your response. As an example, you may be as"ed to bear down as if haing a bowel moement( abnormal heart sounds that occur in response to this maneuer can point to hypertrophic cardiomyopathy.The clinician may firmly massage your carotid artery #located in the nec"$ while your heart rate is closely monitored with an electrocardiogram #)*G or )+G$. The heart,s response to this maneuer can gie clues to a possible diagnosis.Testing A number of medical tests are aailable to help determine the cause of the syncope. -oweer,testing is not always required.Electrocardiogram .ost patients who hae had an episode of syncope will hae an )*G. An )*G can be performed in a clinician,s office and ta"es only a few minutes. Stic"y pads are placed on your chest, abdomen, arm, and leg, and are connected to a recording deice with long, thin cables. This is not painful and there is no ris" of electric shoc" with an )*G.The )*G proides a picture of the electrical actiity passing through the heart muscle. A normal )*G does not necessarily mean that syncope is not caused by a heart rhythm problem. -eart rhythm problemsare often brief, come and go, and may not be present at the moment when the )*G is performed.Rhythm monitoring -eart rhythm monitoring may be recommended to diagnose rhythm problems that come and go and hae not been detected with a routine )*G. This monitoring may be done at home or in the hospital./-olter monitor 0 'ou may be as"ed to wear a monitoring deice, called a -olter monitor, for 12 or 23 hours while performing normal daily actiities at home. The deice is connected to seeral long thin cables that are attached to your chest with stic"y pads #similar to an )*G$. The cables connect to a small, portable machine that can be attached to a belt or strap that is carried oer the shoulder #figure 4$.-oweer, this type of monitoring has limited use and proides a diagnosis in only about 1 to 4 percent of people with syncope. !f you do not experience a syncopal episode while wearing the -olter monitor, the test may need to be repeated, or an alternate form of long%term monitoring may be recommended./)ent recorder 0 An eent recorder may be recommended to capture rhythm problems associated with a syncopal episode. The adantages of an eent recorder compared to a -olter monitor are its small si&e and the ability to monitor for abnormal rhythms for longer periods of time #usually one to two months$.Some deices require you to actiate the recorder when you feel symptoms of a syncopal episode. -oweer, if you lose consciousness and another person is not aailable to assist with the recording, the opportunity to 5capture5 the eent on the monitor may be lost #figure 2$./!ntermittent loop recorders 0 !ntermittent loop recorders were deeloped to capture rhythm problems that occur before the deice is actiated. 6hen you actiate the monitoring deice after regaining consciousness, the )*G recordings from the preious few minutes are retrieed and stored for analysis at a later time.An implantable loop recorder #!78$ proides a way to monitor rhythms oer an extended period of time #eg, 93 to 12 months$. The !78 is implanted under the s"in on the upper left chest area. !t stores eents automatically according to programmed criteria, or can be actiated by the patient. The !78 may be most useful if your symptoms are infrequent and an arrhythmia is suspected, but other forms of testing are negatie or inconclusie.Echocardiogram An echocardiogram is useful for identifying underlying structural heart disease such as hypertrophic cardiomyopathy or significant aortic stenosis. These findings alone do not conclusiely establish the specific cause for syncope.An echocardiogram uses ultrasound #sound waes$ 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 arecording deice and monitor. 'ou are awa"e during the procedure. An echocardiogram does not use radiation.Upright tilt table test This test is often done in healthy patients who hae syncope. 'ou lie on a flat table and are tilted at arious angles while your heart rate and blood pressure are monitored closely #figure :$. 'our response to the change in position can sometimes gie clues about the cause of syncope.Electrophysiology study An electrophysiology study #);S$ may be performed if you hae heart disease or if a rhythm problem is suspected..ost people undergo );S in a hospital setting. 'ou will be gien a sedatie before the procedure but maybe awa"e during testing. The physician uses a local anesthetic to numb a small area oer a blood essel, usually in the groin, and then threads small wires through the blood essels into the heart using x%ray #fluoroscopic$ guidance.