Orthostatic intolerance is defined as the provocation of symptoms upon standing, commonly caused by neurogenic orthostatic hypotension (OH) and postural tachycardia syndrome (POTS), the etiology for which has not been fully uncovered yet. Many reports have described the occurrence of dysautonomia, orthostatic intolerance and POTS following febrile illness, presumably viral and post-vaccine. Furthermore, patients with dysautonomia have higher rates of autoimmune disorders such as Hashimoto thyroiditis and SLE. Recent evidence has shown the presence of adrenergic and cholinergic receptor antibodies in patients with POTS and orthostatic hypotension. In patients with cholinergic receptor antibodies, higher titers correlate with the disease severity. Few reports have shown that immunomodulation therapy resulted in significant improvement in symptoms. In this article, we review the available literature correlating autoimmunity with orthostatic intolerance syndromes. Future studies are warranted to evaluate the prevalence of such antibodies and examine different treatment modalities in this sub group of patients.

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Guidelines for management of normotensive patients with acute pulmonary embolism (PE) emphasize further risk stratification on the basis of right ventricular (RV) size and biomarkers of RV injury or strain; however, the prognostic importance of these factors on long-term mortality is not known. We performed a retrospective cohort study of subjects diagnosed with acute PE from 2010 to 2015 at a tertiary care academic medical center. The severity of initial PE presentation was categorized into three groups: massive, submassive, and low-risk PE. The primary endpoint of all-cause mortality was ascertained using the Centers for Disease Control National Death Index (CDC NDI). A total of 183 subjects were studied and their median follow-up was 4.1 years. The median age was 65 years. The 30-day mortality rate was 7.7% and the overall mortality rate through the end of follow-up was 40.4%. The overall mortality rates for massive, submassive, and low-risk PE were 71.4%, 44.5%, and 28.1%, respectively ( p < 0.001). Landmark analysis using a 30-day cutpoint demonstrated that subjects presenting with submassive PE compared with low-risk PE had increased mortality during both the short- and the long-term periods. The most frequent causes of death were malignancy, cardiac disease, respiratory disease, and PE. Independent predictors of all-cause mortality were cancer at baseline, age, white blood cell count, diabetes mellitus, liver disease, female sex, and initial presentation with massive PE. In conclusion, the diagnosis of acute PE was associated with substantial long-term mortality. The severity of initial PE presentation was associated with both short- and long-term mortality.

Background: Ivabradine is a selective I f channel blocker that reduces heart rate without affecting other cardiovascular functions. In case reports and case series, it was shown to improve symptoms in patients with postural tachycardia syndrome (POTS). Methodology and results:This retrospective study examined patients who were diagnosed with POTS and received ivabradine as part of their treatment. Forty-nine patients (47 females, 95.9%) received ivabradine. The average age was 35.1 ± 10.35 years. The most common symptoms were palpitations and lightheadedness and both improved significantly, 88.4% and 76.1% response rate, respectively. A total of 38 patients reported improvement in their symptoms. In addition, ivabradine resulted in an objective decrease in sitting and standing heart rate (78.1 ± 10.7 vs 72.5 ± 7.6, P-value: 0.01) and (107.4 ± 14.1 vs 95.1 ± 13.7, P-value: < 0.001), respectively, with no significant change in blood pressure. The most common reported side effect was luminous phenomena/visual brightness occurring in nine patients. However, none of the patients stopped ivabradine due to side effects. Conclusion:Our study shows that ivabradine is likely to be effective in treating patients with POTS. Nearly 78% of our cohort reported a significant improvement in symptoms with no major adverse effects reported. A future randomized, placebo-controlled trial is warranted.

Intermittent IV infusions of saline dramatically reduce symptoms and improve quality of life in patients suffering from POTS. Further work should explore its efficacy as a bridge study for patients of high symptomatic severity.