Water drinking and the heart

Effect of cold oral stimulation on orthostatic hypotension in multiple system atrophy: a case study

[Purpose] The aim of this case study is to reconsider the method for preventing orthostatic hypotension in multiple system atrophy. [Participant and Methods] The case was that of a 70-year-old female with multiple system atrophy who experienced frequent falls and orthostatic hypotension. An orthostatic test was performed, and the effect of cold oral stimulation before standing was compared with no stimulation. Outcome measures were blood pressure, heart rate variability and autonomic variables. [Results] In the control test, blood pressure decreased from 150/72 mmHg in the supine position to 98/58 mmHg in the standing position. Heart rate increased from 71 bpm to 82 bpm, high frequency declined from 16.48 msec² to 14.07 msec², and low/high frequency increased from 2.56 to 5.13. Cold stimulation in the standing position induced changes in blood pressure from 168/82 mmHg to 104/72 mmHg, heart rate from 73 bpm to 83 bpm, high frequency from 61.29 msec² to 24.56 msec², and low/high frequency from 1.45 to 6.33 msec². [Conclusion] Standing after cold stimulation affected autonomic variables, but did not affect the heart rate or blood pressure, possibly because of damaged peripheral blood vessels. Further research is required to demonstrate the effect of cold stimulation on orthostatic hypotension.

Evidence-based treatment of neurogenic orthostatic hypotension and related symptoms

Neurogenic orthostatic hypotension, postprandial hypotension and exercise-induced hypotension are common features of cardiovascular autonomic failure. Despite the serious impact on patient’s quality of life, evidence-based guidelines for non-pharmacological and pharmacological management are lacking at present. Here, we provide a systematic review of the literature on therapeutic options for neurogenic orthostatic hypotension and related symptoms with evidence-based recommendations according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Patient’s education and non-pharmacological measures remain essential, with strong recommendation for use of abdominal binders. Based on quality of evidence and safety issues, midodrine and droxidopa reach a strong recommendation level for pharmacological treatment of neurogenic orthostatic hypotension. In selected cases, a range of alternative agents can be considered (fludrocortisone, pyridostigmine, yohimbine, atomoxetine, fluoxetine, ergot alkaloids, ephedrine, phenylpropanolamine, octreotide, indomethacin, ibuprofen, caffeine, methylphenidate and desmopressin), though recommendation strength is weak and quality of evidence is low (atomoxetine, octreotide) or very low (fludrocortisone, pyridostigmine, yohimbine, fluoxetine, ergot alkaloids, ephedrine, phenylpropanolamine, indomethacin, ibuprofen, caffeine, methylphenidate and desmopressin). In case of severe postprandial hypotension, acarbose and octreotide are recommended (strong recommendation, moderate level of evidence). Alternatively, voglibose or caffeine, for which a weak recommendation is available, may be useful.

The Treatment of Primary Orthostatic Hypotension

OBJECTIVE

To review the efficacy and safety of pharmacological and nonpharmacological strategies used to treat primary orthostatic hypotension (OH).

DATA SOURCES

A literature review using PubMed and MEDLINE databases searching hypotension, non-pharmacological therapy, midodrine, droxidopa, pyridostigmine, fludrocortisone, atomoxetine, pseudoephedrine, and octreotide was performed.

STUDY SELECTION AND DATA EXTRACTION

Randomized or observational studies, cohorts, case series, or case reports written in English between January 1970 and November 2016 that assessed primary OH treatment in adult patients were evaluated.

DATA SYNTHESIS

Based on the chosen criteria, it was found that OH patients make up approximately 15% of all syncope patients, predominantly as a result of cardiovascular or neurological insults, or offending medication. Nonpharmacological strategies are the primary treatment, such as discontinuing offending medications, switching medication administration to bedtime, avoiding large carbohydrate-rich meals, limiting alcohol, maintaining adequate hydration, adding salt to diet, and so on. If these fail, pharmacotherapy can help ameliorate symptoms, including midodrine, droxidopa, fludrocortisone, pyridostigmine, atomoxetine, sympathomimetic agents, and octreotide.

CONCLUSIONS

Midodrine and droxidopa possess the most evidence with respect to increasing blood pressure and alleviating symptoms. Pyridostigmine and fludrocortisone can be used in patients who fail to respond to these agents. Emerging evidence with low-dose atomoxetine is promising, especially in those with central autonomic failure, and may prove to be a viable alternative treatment option. Data surrounding other therapies such as sympathomimetic agents or octreotide are minimal. Medication management of primary OH should be guided by patient-specific factors, such as tolerability, adverse effects, and drug-drug and drug-disease interactions.

The management of orthostatic hypotension in Parkinson's disease

Orthostatic hypotension (OH) is a common and disabling symptom affecting Parkinson's disease (PD) patients. We present the effect of the different therapies commonly used to manage PD on this clinical manifestation. For this purpose, we describe the relationship between OH and the current treatments employed in PD, such as L-DOPA, dopaminergic agonists, and continuous dopaminergic stimulation therapies. Additionally, we review the therapeutic measures that could be used to ameliorate OH. There are different approaches to deal with this manifestation, including pharmacological and non-pharmacological treatments, although none of them is specifically aimed for treating OH in PD.

Water drinking in the management of orthostatic intolerance due to orthostatic hypotension, vasovagal syncope and the postural tachycardia syndrome

Water drinking recently has been shown to raise blood pressure in normal subjects and in patients with autonomic failure who have orthostatic hypotension. However, in normal young subjects, ingestion of approximately 500 ml has no pressor effect; but in older subjects there is an increase in blood pressure. An even greater rise in blood pressure occurs in cases with autonomic failure. The possible mechanisms responsible for the pressor response to water include neural and humoral factors; fluid redistribution also needs to be considered. This review will concentrate on the water pressor response in normal subjects and different groups of patients with autonomic diseases who have orthostatic intolerance, on the mechanisms that could be involved, and on whether this pressor response may be used in the management of orthostatic hypotension, vasovagal syncope and the postural tachycardia syndrome.