Gibbons, Christopher H.

Sinus tachycardia (ST) is ubiquitous, but its presence outside of normal physiological triggers in otherwise healthy individuals remains a commonly encountered phenomenon in medical practice. In many cases, ST can be readily explained by a current medical condition that precipitates an increase in the sinus rate, but ST at rest without physiological triggers may also represent a spectrum of normal. In other cases, ST may not have an easily explainable cause but may represent serious underlying pathology and can be associated with intolerable symptoms. The classification of ST, consideration of possible etiologies, as well as the decisions of when and how to intervene can be difficult. ST can be classified as secondary to a specific, usually treatable, medical condition (eg, pulmonary embolism, anemia, infection, or hyperthyroidism) or be related to several incompletely defined conditions (eg, inappropriate ST, postural tachycardia syndrome, mast cell disorder, or post-COVID syndrome). While cardiologists and cardiac electrophysiologists often evaluate patients with symptoms associated with persistent or paroxysmal ST, an optimal approach remains uncertain. Due to the many possible conditions associated with ST, and an overlap in medical specialists who see these patients, the inclusion of experts in different fields is essential for a more comprehensive understanding. This article is unique in that it was composed by international experts in Neurology, Psychology, Autonomic Medicine, Allergy and Immunology, Exercise Physiology, Pulmonology and Critical Care Medicine, Endocrinology, Cardiology, and Cardiac Electrophysiology in the hope that it will facilitate a more complete understanding and thereby result in the better care of patients with ST.

Objective: To understand the patient and caregiver experience with the management of neurogenic orthostatic hypotension (nOH) Background: nOH is a sustained reduction in blood pressure (BP) with postural change associated with autonomic dysfunction. Clinical symptoms may include falls, leading to activity limits and a diminished sense of well-being. Methods: A US-based survey designed by the authors was conducted by Harris Poll. Eligible participants had Parkinson disease (PD), multiple system atrophy, or pure autonomic failure and ≥1 of the following: orthostatic hypotension (OH), nOH, low BP, OH/nOH symptoms, or were caregivers of eligible patients. Descriptive statistics are reported. Results: PD was the most frequent underlying diagnosis (Table 1) . Healthcare provider (HCP) communication with patients was rated as satisfactory by ≥75% of respondents, yet when nOH symptoms were first discussed with the HCP, only 35% of patients and 31% of caregivers reported the patient received guidance on management. The most frequently recommended interventions are listed in Table 1 ; 25% of patients reported that no interventions were recommended. Medication prescribed to treat nOH was reported by 34% of patients and 45% of caregivers. Among patients treated, 79% of patients and 71% of caregivers said that the patient’s symptoms were somewhat to very well managed. Conclusions: Survey findings suggest the need for increased awareness of nOH and engagement with patients and caregivers regarding symptom management. A variety of interventions were recommended; no single treatment approach was noted. Respondents felt nOH symptoms were at least somewhat well managed with treatment.

Objective: To understand the burden and impact of symptoms of neurogenic orthostatic hypotension (nOH) on patients Background: nOH and its symptoms such as dizziness/lightheadedness are common in patients with Parkinson disease (PD) and other forms of autonomic dysfunction. Methods: An author-designed, US-based survey was conducted by Harris Poll. Eligible participants were aged ≥18 years with PD, multiple system atrophy (MSA), or pure autonomic failure and ≥1 of the following: orthostatic hypotension, nOH, low BP, OH/nOH symptoms, or were caregivers of eligible patients. Results: Most patients (90%) had a diagnosis of PD, and most caregivers (88%) cared for a patient with PD (Table 1) . Patients (34%) and caregivers (49%) reported experiencing nOH symptoms before PD or MSA motor symptoms and >40% indicated that nOH symptoms were more troublesome than motor manifestations of PD or MSA. Less than a quarter (22%) of respondents suggested symptoms were most severe in the morning; more (30%) reported a consistent severity throughout the day. Patients (40%) and caregivers (63%) reported trouble managing symptoms during the day. In the past 12 months, a fall due to nOH symptoms was reported by 57% of patients and 80% of caregivers. Conclusions: These findings suggest that nOH symptoms may predate the onset of motor symptoms in neurodegenerative conditions linked to alpha-synuclein pathology. Many respondents report nOH symptoms are the same severity through the day. Patients with nOH may have trouble managing symptoms and note an increased risk for falls.

Objective: To understand the challenges to diagnosis in patients with neurogenic orthostatic hypotension (nOH) Background: nOH is a sustained reduction in blood pressure (BP) with postural change associated with autonomic dysfunction. Despite symptoms of nOH, many patients struggle to find an accurate diagnosis. Methods: An online, US-based survey designed by the authors was conducted by Harris Poll. Eligible participants were ≥18 years of age with Parkinson disease, multiple system atrophy, or pure autonomic failure and ≥1 of the following: orthostatic hypotension (OH), nOH, low BP, OH/nOH symptoms, or were caregivers of eligible participants. Results: The survey included 363 patients and 128 caregivers. Groups were separate, where caregivers were not the caregivers to patient responders. Respondents indicated that patients experienced nOH symptoms long term (Table 1) . Most patients (69%) and caregivers (59%) reported discussing nOH symptoms with a healthcare provider (HCP) within the first year of symptom onset, but only 36% of patients and 16% of caregivers reported a formal diagnosis of OH or nOH. Of those with a formal diagnosis, the majority of patients (50%) were frustrated by the path to diagnosis and more than 40% of patients and caregivers reported that the patient saw ≥3 HCPs before diagnosis. After diagnosis, most patients (70%) and caregivers (60%) reported improved symptom management. Conclusions: This survey reveals that patients and caregivers may find the path to nOH diagnosis challenging and suggests increased awareness among HCPs is needed. Once a diagnosis is made nOH symptoms are better managed.

Objective Blunted tachycardia during hypotension is a characteristic feature of patients with autonomic failure, but the range has not been defined. This study reports the range of orthostatic heart rate (HR) changes in patients with autonomic failure caused by neurodegenerative synucleinopathies. Methods Patients evaluated at sites of the U.S. Autonomic Consortium (NCT01799915) underwent standardized autonomic function tests and full neurological evaluation. Results We identified 402 patients with orthostatic hypotension (OH) who had normal sinus rhythm. Of these, 378 had impaired sympathetic activation (ie, neurogenic OH) and based on their neurological examination were diagnosed with Parkinson disease, dementia with Lewy bodies, pure autonomic failure, or multiple system atrophy. The remaining 24 patients had preserved sympathetic activation and their OH was classified as nonneurogenic, due to volume depletion, anemia, or polypharmacy. Patients with neurogenic OH had twice the fall in systolic blood pressure (SBP; −44 ± 25 vs −21 ± 14 mmHg [mean ± standard deviation], p < 0.0001) but only one‐third of the increase in HR of those with nonneurogenic OH (8 ± 8 vs 25 ± 11 beats per minute [bpm], p < 0.0001). A ΔHR/ΔSBP ratio of 0.492 bpm/mmHg had excellent sensitivity (91.3%) and specificity (88.4%) to distinguish between patients with neurogenic from nonneurogenic OH (area under the curve = 0.96, p < 0.0001). Within patients with neurogenic OH, HR increased more in those with multiple system atrophy ( p = 0.0003), but there was considerable overlap with patients with Lewy body disorders. Interpretation A blunted HR increase during hypotension suggests a neurogenic cause. A ΔHR/ΔSBP ratio < 0.5 bpm/mmHg is diagnostic of neurogenic OH. Ann Neurol 2018;83:522–531

ObjectiveTo define the clinical features and biomarkers that predict which patients with pure autonomic failure will develop Parkinson disease, dementia with Lewy bodies, or multiple system atrophy.MethodsOne hundred patients who presented with pure autonomic failure were recruited at 5 medical centers in the United States. Seventy‐four patients agreed to be followed prospectively. Patients underwent clinical evaluations including neurological rating scales, sleep questionnaires, smell test, and sympathetic and parasympathetic cardiovascular autonomic function tests.ResultsAt enrollment, patients were 68 ± 12 years old (median ± interquartile range) and had had autonomic failure for 5 ± 7 years. Within 4 years of follow‐up, 25 of 74 subjects (34%) developed dementia with Lewy bodies (n = 13), Parkinson disease (n = 6), or multiple system atrophy (n = 6). The presence of probable rapid eye movement (REM) sleep behavior disorder was strongly associated with the development of a manifest central nervous system (CNS) synucleinopathy (odds ratio = 7.1). Patients who phenoconverted to multiple system atrophy had younger age at onset of autonomic failure, severe bladder/bowel dysfunction, preserved olfaction, and a cardiac chronotropic response upon tilt > 10 beats per minute. Those who phenoconverted to Parkinson disease or dementia with Lewy bodies had decreased olfaction, a lesser chronotropic response to tilt, and a longer duration of illness. The small group of patients retaining the pure autonomic failure phenotype had very low plasma norepinephrine levels, slow resting heart rate, no REM sleep behavior disorder, and preserved smell.InterpretationPatients presenting with pure autonomic failure are at high risk of phenoconverting to a manifest CNS synucleinopathy. Specific clinical features predict future diagnosis. Ann Neurol 2017;81:287–297