Active clinical trials for "Syncope"

This study will examine the effectiveness of the drug propranolol in preventing fainting in patients with sympathoadrenal imbalance (SAI). SAI is a particular pattern of nervous system and chemical responses in which the blood vessels in skeletal muscles do not remain constricted appropriately during standing for a long time. This can lower blood pressure and cause fainting. Propranolol Inderal (registered trademark) is a Food and Drug Administration-approved drug that belongs to a class of drugs called beta-blockers. These drugs slow the heart rate and maintain blood pressure in certain situations. Patients 18 years of age and older with SAI may be eligible for this study. Screening includes a tilt table test, described below, to determine if the patient has a particular chemical pattern in the blood. Patients enrolled in the study take propranolol pills in increasing doses during the first week of the study to determine the proper dose for the individual. Then, the drug is stopped until the experimental phase of the study begins. In this phase, patients are randomly assigned to take either propranolol or placebo (look-alike pill with no active ingredient) for 4 days. On the fourth day, the patient undergoes a tilt table test to determine whether the treatment affects the patient's ability to tolerate tilt. For this test, the patient lies on a padded table with a motorized tilt mechanism that can move the patient from a flat position to an upright position in about 10 seconds. The patient remains upright for up to 45 minutes while the following measurements are taken: Arterial blood pressure monitoring and arterial blood sampling. A catheter (thin, plastic tube) is inserted into an artery in the elbow crease area of the arm or the wrist. This catheter allows continuous blood pressure monitoring and sampling of arterial (oxygenated) blood during the tilt test. Venous blood sampling and measurement of epinephrine and norepinephrine release. A catheter is inserted into a vein in each arm, one to collect venous (deoxygenated) blood samples, and the other to inject radioactive epinephrine (adrenaline) and norepinephrine (noradrenaline). These radioactive drugs, or ,tracers, allow measurement of the rate of release of the body's own norepinephrine and epinephrine into the bloodstream. Physiologic measurements. Blood pressure, heart rate, and EKG are measured continuously during the tilt test session, and blood flows and skin electrical conduction are measured intermittently. Blood flow is measured using sensors applied to the skin and a blood pressure cuff around the limb. For skin blood flow measurements, a laser beam scans the skin surface. The skin electrical conduction test measures how well the skin conducts electricity. This is measured through sensors placed on the fingers or other sites. The effects of the test drug are allowed to wear off for 1 week, after which the entire tilt test procedure is repeated. Patients who were given propranolol for the first test session take placebo for the repeat session, and those who were given placebo take propranolol.

Syncope is defined as transient loss of consciousness associated with inability to maintain postural tone with rapid and spontaneous recovery. The purpose of this study is to assess the effects of sublingual administration of a new medication called CPC on tilt-induced syncope in patients with a history of vasovagal syncope (VVS) or near syncope. 140 participants were randomized at the University of Wisconsin - Madison. Each participant will be in the study for 1 day.

The purpose of this study is to determine whether point-of-care (bedside) ultrasound assists physicians in the evaluation and management of patients with syncope.

OBJECTIVES: Determine the efficacy of midodrine, a selective alpha 1 adrenergic agonist, in preventing neurally mediated syncope.

The purpose of this study is to assess whether the Closed Loop Stimulation (CLS) in addition to the DDD pacing is effective in reducing syncopal recurrences. The study hypothesis is that DDD pacing with CLS stimulation is able to prevent syncopal recurrences completely or partially by transforming syncope in pre-syncope.

Study Objective The purpose of this study is to evaluate the efficacy of bradycardia pacing with respect to patient symptoms in patients with bifascicular block and syncope of unexplained origin.

The main question in the study is whether people taking fludrocortisone are less likely to faint than people taking an inactive pill called a placebo. Fludrocortisone is a drug that stimulates the body to retain salt and water. The investigators know from some studies that it might prevent people from fainting at home and in the community, while they are carrying on with their lives. There is some evidence that salt and water retention help prevent fainting, but no one has a clear idea about whether this is true. This study will try to determine if that is true.

This study will examine the effectiveness of the drug propranolol in preventing fainting in patients with sympathoadrenal imbalance (SAI). SAI is a particular pattern of nervous system and chemical responses in which the blood vessels in skeletal muscles do not remain constricted appropriately during standing for a long time. This can lower blood pressure and cause fainting. Propranolol (Inderal® (Registered Trademark)) is a Food and Drug Administration-approved drug that belongs to a class of drugs called beta-blockers. These drugs slow the heart rate and maintain blood pressure in certain situations. Children between 10 and 17 years of age with frequent fainting or near-fainting due to SAI may be eligible for this study. Children must experience severe dizzy episodes at least once every 2 months or fainting episodes at least once every 4 months. The condition must be severe enough to affect the child's quality of life or to have forced the child to alter his or her life routines to accommodate to the illness. Screening includes a tilt table test, described below, to determine if the child has a particular chemical pattern in the blood. Children enrolled in the study take propranolol pills in increasing doses during the first week of the study to determine the proper dose for the individual. Then, the drug is stopped until the experimental phase of the study begins. In this phase, children are randomly assigned to take either propranolol or placebo (a look-alike pill with no active ingredient) for a maximum of 3 days. On the fourth day, the child undergoes a tilt table test to determine whether the treatment affects his or her ability to tolerate tilt. For this test, the child lies on a padded table with a motorized tilt mechanism that can move the child from a flat position to an upright position in about 10 seconds. The child remains upright for up to 40 minutes while the following measurements are taken: Blood sampling: Blood is drawn through a catheter (thin plastic tube) placed in an arm vein. This allows repeated sampling without repeated needle sticks. Samples are collected before starting the tilt test, about every 4 minutes during the test, immediately when a drop in blood pressure is detected or symptoms develop, and after 10 minutes of recovery lying flat. A maximum of 12 samples are collected for each tilt test. Physiologic measurements: Blood pressure, heart rate, and electrocardiogram (EKG) are measured continuously during the tilt test session, and blood flows and skin electrical conduction are measured intermittently. Blood flow is measured using sensors applied to the skin and a blood pressure cuff around the limb. For skin blood flow measurements, a laser beam scans the skin surface. The skin electrical conduction test measures how well the skin conducts electricity. This is measured through sensors placed on the tips of two fingers. Respiration and breathing rate are monitored by an elastic cloth band around the chest. Self-report questionnaires: Patients or their parents complete a questionnaire about the child's symptoms before and during treatment. The effects of the test drug are allowed to wear off for up to 1 week, after which the entire tilt test procedure is repeated. Patients who were given propranolol for the first test session take placebo for the repeat session, and those who were given placebo take propranolol.

Identifying the mechanism of non-cardiac syncope is the essential prerequisite for an effective personalized therapy. Aim of this multicentre, prospective, cross-sectional, observational study is to assess effectiveness and diagnostic yield of a two-step standardized assessment which consists of 24-hour ambulatory blood pressure monitoring (ABPM) and of tilt-table Short Cardiovascular Autonomic Function Battery (SCAFB) which consists in carotid sinus massage (CSM), limited to patients ≥40-year-old, standing test, and head-up tilt test (HUT) performed one after the other in an uninterrupted sequence as a single procedure on a tilt table

Postural orthostatic tachycardia syndrome (POTS) is a common cause of orthostatic intolerance in adolescents and adults. Compression stockings are commonly recommended as a treatment modality for POTS, but the effects of abdominal and lower extremity compression during tilt table testing have not been measured in adolescent patients. The aims of our study are to compare heart-rate changes and symptom onset during tilt table testing (a) with and without abdomen/lower extremity compression and (b) with abdominal compression only versus lower extremity compression only. During phase 1, 20 adolescents with POTS will undergo up to 10 minutes of tilt without compression (trial #1), a repeat study of up to 10 minutes with full compression (trial #2), and a third study without compression up to 10 minutes (trial #3). Compression will be performed using the non-inflatable Zoex anti-shock garment. During study phase 2, an additional 20 adolescent POTS patients will undergo up to 10 minutes of tilt without compression (trial #1), a repeat study of up to 10 minutes with abdominal compression only [n=10] or lower extremity compression only [n=10] (trial #2), and a third study repeated without compression up to 10 minutes (trial #3). To limit compression to the abdomen only, we will use the Zoex garment strap numbers 4 and 5 (thigh and abdomen) without straps 1-3 (lower extremities). For lower extremity-only compression, we will use Zoex garment straps 1-4 (lower extremity and thigh) without strap 5. Data collected will include mean and peak heart rates and timing of symptoms with each trial. A paired-samples t-test will be used to compare mean heart rates between trials for each study phase. Hazard analyses will be used to assess time-based endpoints.