Postural Tachycardia Syndrome
Conditions
Keywords
POTS
Brief summary
This study is to determine different chemical levels in the blood during a low salt diet. This study will compare normal volunteers to those with Postural Tachycardia Syndrome (POTS)
Detailed description
Patients with postural tachycardia syndrome had a subnormal increment in aldosterone with upright posture, which might reflect a blunted adrenal response to stimulation upon assuming upright posture. In this AIM, we propose to assess the adrenal response to aldosterone stimulation with intravenous adrenocorticotropin hormone. For this protocol, subjects enrolled in the parent study will be approached about this sub-study. Subjects will be assured that they are not required to participate in this study even if they choose to participate in the parent study. There will be no randomization for this specific sub-study. The order of diets (low sodium vs. high sodium) will be performed as a part of the parent study, and not as a part of this sub-study. This sub-study will only be performed in the LOW dietary salt phase. All subjects will be previously screened and evaluated as a part of the parent study. No further screening will be performed exclusively for this study. Women of childbearing potential will have had a serum pregnancy test as a part of the parent study. Pregnant women will not be allowed to participate.
Interventions
DRUGCosyntropin administration
After 30 minutes of rest in the seated position, participants will be given cosyntropin intravenously. Blood samples will be taken 30 minutes pre-drug administration, 30 minutes post and 60 minutes post drug administration.
Sponsors
National Institutes of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Vanderbilt University
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
Subjects will be enrolled in the parent study Dietary Salt in Postural Tachycardia Syndrome during the LOW SALT phase Postural Tachycardia Syndrome Diagnosed with postural tachycardia syndrome by the Vanderbilt Autonomic Dysfunction Center Increase in heart rate ≥30 beats/min with position change from supine to standing (10 minutes) Chronic symptoms consistent with POTS that are worse when upright and get better with recumbence * Control Subjects * Healthy, non-obese, non-smokers without orthostatic tachycardia * Selected to match profiles of POTS patients (gender, age) * Not using vasoactive medication * Age between 18-50 years * Male and female subjects are eligible. * Able and willing to provide informed consent
Exclusion criteria
* Overt cause for postural tachycardia (such as acute dehydration) * Inability to give, or withdrawal of, informed consent * pregnant * Other factors which in the investigator's opinion would prevent the subject from completing the protocol.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Alldosterone Increase in Response to Adrenocorticotropin Hormone (ACTH). | 30 minutes after injection of ACTH | To assess the adrenal responsiveness to adrenocorticotropin hormone (ACTH), as measured by plasma aldosterone level, is contributing to the pathophysiology of Orthostatic Tachycardia. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Low Salt Diet POTS After 7 days of being on a low salt diets, POTS patients and controls will be asked to undergo Cosyntropin administration: After 30 minutes of rest in the seated position, participants will be given cosyntropin intravenously. Blood samples will be taken 30 minutes pre-drug administration, 30 minutes post and 60 minutes post drug administration. | 8 |
| Low Salt Diet Controls After 7 days of being on a low salt diets, POTS patients and controls will be asked to undergo Cosyntropin administration: After 30 minutes of rest in the seated position, participants will be given cosyntropin intravenously. Blood samples will be taken 30 minutes pre-drug administration, 30 minutes post and 60 minutes post drug administration. | 5 |
| Total | 13 |
Baseline characteristics
| Characteristic | Low Salt Diet POTS | Low Salt Diet Controls | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 8 Participants | 5 Participants | 13 Participants |
| Age, Continuous | 33 years STANDARD_DEVIATION 6 | 30 years STANDARD_DEVIATION 8 | 32 years STANDARD_DEVIATION 7 |
| Baseline Aldosterone | 34 nanograms/dL STANDARD_DEVIATION 20.1 | 33 nanograms/dL STANDARD_DEVIATION 14.2 | 33.5 nanograms/dL STANDARD_DEVIATION 16.2 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 8 Participants | 5 Participants | 13 Participants |
| Region of Enrollment United States | 8 participants | 5 participants | 13 participants |
| Sex: Female, Male Female | 8 Participants | 5 Participants | 13 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 8 | 0 / 5 |
| other Total, other adverse events | 0 / 8 | 0 / 5 |
| serious Total, serious adverse events | 0 / 8 | 0 / 5 |
Outcome results
Primary
Alldosterone Increase in Response to Adrenocorticotropin Hormone (ACTH).
To assess the adrenal responsiveness to adrenocorticotropin hormone (ACTH), as measured by plasma aldosterone level, is contributing to the pathophysiology of Orthostatic Tachycardia.
Time frame: 30 minutes after injection of ACTH
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Low Salt Diet POTS | Alldosterone Increase in Response to Adrenocorticotropin Hormone (ACTH). | 52.5 nanograms/dL | Standard Deviation 15.7 |
| Low Salt Diet Controls | Alldosterone Increase in Response to Adrenocorticotropin Hormone (ACTH). | 57.9 nanograms/dL | Standard Deviation 26.4 |