1/14. Atrioventricular dissociation as a cause of syncope determined by head-up tilt test.This report describes a patient with syncopal attacks in a sitting position on a reclining seat, in whom atrioventricular dissociation due to accelerated ventricular rhythm was determined to be the cause by recording of the electrocardiogram, blood pressure, and mitral and aortic Doppler flow during a 60 degree head-up tilt test.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
2/14. Familial vasovagal syncope and pseudosyncope: observations in a case with both natural and adopted siblings.This report describes an 11-year-old girl with recurrent syncope beginning at the age of 2 1/2 years. Her paternal grandmother, father, and three of her five natural siblings had similar symptoms, often linked to emotional upsets. There were three adopted children from a single family, and none of these had syncope. Prior to referral there was an increase in attacks, some with convulsions, but with no other features of epilepsy. Vasovagal syncope was confirmed. However, continuous electroencephalogram, blood pressure, and heart rate recordings during attacks indicated that in some episodes there was neither cardiovascular change nor epileptiform activity, implying feigned syncope (pseudosyncope) with pseudoseizures. A psychological origin was sought, found, and in part rectified. The separation of vasovagal syncope from pseudosyncope, in the context of the family history, is discussed.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
3/14. Valsalva-induced syncope during apnea diving.A young man had two dangerous episodes of transient loss of consciousness during apnea diving in a swimming pool. Medical and neurologic examination results were normal. Standard autonomic test results (including heart rate variability, baroreflex sensitivity, tilt-table test, and Valsalva ratio) were unremarkable, with the exception of an increased blood pressure decrease during early phase II of the valsalva maneuver. syncope with arrhythmic myoclonic jerks could be evoked by a strong straining maneuver. Simultaneous physiologic recordings showed extreme blood pressure and cerebral blood flow velocity decreases and electroencephalographic slowing during syncope. The electrocardiogram showed a continuous sinus rhythm with a progressive tachycardia. The authors' findings were not compatible with baroreflex failure or vasovagal mechanisms (Bezold-Jarisch reflex activation) as the underlying causes. The authors concluded that mechanical factors (strong reduction of blood reflux to the heart) in combination with a reduced threshold of the brain for developing ischemia-related arrhythmic myoclonic jerks were responsible for Valsalva-induced syncope in the patient.- - - - - - - - - - ranking = 2keywords = pressure (Clic here for more details about this article) |
4/14. eye examination-induced syncope role of trigeminal afferents.The role of trigeminal afferents in a patient with eye examination - induced syncope was investigated. A head-up tilt test precipitated presyncope with a reduced blood pressure. On a separate day, the application of Schirmer's lacrimation test strips in each conjunctival sac caused vasodepression and cardioinhibition. Topical administration of 0.5 % proparacaine hydrochloride produced ocular anesthesia and loss of corneal reflexes. Schirmer's test following anesthesia again caused presyncope with reductions in blood pressure and heart rate. The supramaximal stimulus to a supraorbital nerve before and after topical anesthesia did not affect blood pressure or heart rate. It is concluded that trigeminal afferents did not induce vasodepressive syncope in this patient. Instead, corticohypothalamic centers may have played an important role.- - - - - - - - - - ranking = 3keywords = pressure (Clic here for more details about this article) |
5/14. association between vasovagal hypotension and low sympathetic neural activity during presyncope.Recent studies suggest that an underlying mechanism for susceptibility of patients and astronauts to presyncope includes hypoadrenergic responses to orthostatic stress. However, data used to reach this conclusion are open to various interpretations. In this report, maintenance of sympathetic neural activity (MSNA; peroneal nerve microneurography) during -60 mmHg lower body negative pressure (LBNP) was associated with maintenance of orthostatic tolerance, and disappearance of MSNA was associated with hypotension and pre-syncope. However, MSNA was substantially higher during progressive increases of negative pressure in the presyncopal subject, compared to the non-presyncopal subjects. The data from this case report question the notion that orthostatic hypotension occurs due to inadequate sympathetic neural activation during orthostatic stress in apparently normal, healthy subjects.- - - - - - - - - - ranking = 2keywords = pressure (Clic here for more details about this article) |
6/14. Decreased bispectral index as an indicator of syncope before hypotension and bradycardia in two patients with needle phobia.We report two cases who exhibited a decrease in their bispectral index (BIS) score, associated with syncope during venipuncture in patients with suspected needle phobia. In case 1, the reduction in BIS score occurred during the development of hypotension and bradycardia and may well have been caused by cerebral hypoperfusion. In case 2, the patient lost consciousness with decreasing BIS score before hypotension and bradycardia; this patient's condition could not be completely explained by cerebral hypoperfusion as a result of a vasovagal reflex because the patient's blood pressure and heart rate remained normal during the syncopal episode.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
7/14. Severe vasovagal attack: an unusual cause of abruptio placentae.CASE REPORT: abruptio placentae occurred in a 29 years old woman following a vasovagal episode. Her medical history was free from all the commonly accepted risk factors for abruption. DISCUSSION: We speculate that the restoration of placental blood flow caused a sudden increase in uteroplacental blood pressure, and induces rupture of some vessels, causing a progressively growing retroplacental hematoma and placental detachment.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
8/14. Malignant vasovagal syndrome in two patients with wolff-parkinson-white syndrome.The presence of Wolff-Parkinson-White (WPW) syndrome in patients presenting with syncope suggests that tachyarrhythmia may be the cause. However, the symptoms require careful evaluation. Two young patients presented with syncope and were found to have WPW syndrome on their ECG. In both patients symptoms were suggestive of vasovagal syncope. During tilt testing, both the patients developed their typical symptoms with a fall in blood pressure and heart rate confirming the diagnosis of malignant vasovagal syndrome.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
9/14. Applied tension treatment of vasovagal syncope during pregnancy.Vasovagal syncope is a common clinical problem that is often difficult and expensive to diagnose and treat. Applied tension is a behavioral treatment approach that has been demonstrated to be efficacious for the treatment of vasovagal syncope associated with injection phobia. The present case study evaluated the treatment of vasovagal syncope in a 41-year-old pregnant patient with injection phobia. The treatment included the use of applied muscle tension to increase blood pressure and prevent syncope during graduated exposure to increasingly greater anxiety-provoking stimuli. After completion of the treatment, the patient was able to undergo a blood draw and other medical procedures involving exposure to needles, with significantly reduced anxiety and no episodes of syncope. Applied tension is an effective and relatively inexpensive treatment for patients with vasovagal syncope related to injection phobia and may hold promise as a treatment for other types of syncope.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
10/14. When the heart is stopped for good: hypotension-bradycardia paradox revisited.In vasovagal syncope, occurrence of bradycardia/asystole in the wake of hypotension has often been considered paradoxical. The major objective of this teaching module is to critically examine the pathophysiological mechanism and significance of the hypotension-bradycardia paradox unique to this condition. We narrate here how we discussed the pathophysiology of vasovagal syncope in a large classroom session attended by 275 doctors and medical students. A case study was used to describe the typical clinical presentation of vasovagal syncope. The pathophysiological mechanisms involved were then discussed systematically using a series of open-ended questions. We made it clear 1) that the occurrence of bradycardia or asystole in the face of acute severe hypotension is a mechanism to possibly minimize further blood loss, prevent myocardial damage, and increase ventricular filling; and 2) that fainting, which occurs as a consequence of this, is a homeostatic mechanism that serves to restore venous return and cerebral blood flow before blood pressure is normalized by neural reflex mechanisms. Eighty-four percent of participants reported that they were satisfied with the session. The information contained herein could be used to explain to any suitable audience the neural regulation of blood pressure in the face of acute severe hypotension and the pathophysiology of vasovagal syncope.- - - - - - - - - - ranking = 2keywords = pressure (Clic here for more details about this article) |
| | Next -> |