Neurocardiogenic Syncope and Related Disorders of Orthostatic Intolerance

Cardiology Department of Medicine, the Medical University of Ohio, Toledo, Ohio 43614, USA.
Circulation (Impact Factor: 14.43). 07/2005; 111(22):2997-3006. DOI: 10.1161/CIRCULATIONAHA.104.482018
Source: PubMed


The ANS is both complex and diverse and is involved in essentially every organ system and in the majority of disease processes. Disruptions in this system can be incredibly diverse in presentation, yet often culminate in a failure to maintain normotension, with resultant near syncope and syncope. A working knowledge of these disorders is required for both their recognition and their management. Further investigations will aid in our understanding of this wide range of disorders and at the same time identify better diagnostic and therapeutic modalities.

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    • "Because a relatively small proportion of OH patients in our study had comorbid Parkinson's disease (22.6%) or multiple system atrophy (7.5%), we speculate this group is mainly composed of patients with pure autonomic failure. The similarity of clinical characteristics between the OH patients included in our study (mean age, 67.1 years; male-to-female ratio, 1.8∶1; Table 1) and patients with autonomic failure included in previous studies [4], [29] further support this hypothesis. Our finding of prolonged QTc interval, increased QTc dispersion, and widespread impairment in autonomic function domains in OH patients could be interpreted as sympathetic and parasympathetic dysfunctions, which are characteristic features of pure autonomic failure. "
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    ABSTRACT: We performed this study to determine whether electrocardiographic corrected QT (QTc) interval predicts alterations in sympathovagal balance during orthostatic intolerance (OI). We reviewed 1,368 patients presenting with symptoms suggestive of OI who underwent electrocardiography and composite autonomic function tests (AFTs). Patients with a positive response to the head-up tilt test were classified into orthostatic hypotension (OH), neurocardiogenic syncope (NCS), or postural orthostatic tachycardia syndrome (POTS) groups. A total of 275 patients (159 OH, 54 NCS, and 62 POTS) were included in the final analysis. Between-group comparisons of OI symptom grade, QTc interval, QTc dispersion, and each AFT measure were performed. QTc interval and dispersion were correlated with AFT measures. OH Patients had the most severe OI symptom grade and NCS patients the mildest. Patients with OH showed the longest QTc interval (448.8±33.6 msec), QTc dispersion (59.5±30.3 msec) and the lowest values in heart rate response to deep breathing (HRDB) (10.3±6.0 beats/min) and Valsalva ratio (1.3±0.2). Patients with POTS showed the shortest QTc interval (421.7±28.6 msec), the highest HRDB values (24.5±9.2 beats/min), Valsalva ratio (1.8±0.3), and proximal and distal leg sweat volumes in the quantitative sudomotor axon reflex test. QTc interval correlated negatively with HRDB (r = -0.443, p<0.001) and Valsalva ratio (r = -0.425, p<0.001). We found negative correlations between QTc interval and AFT values representing cardiovagal function in patients with OI. Our findings suggest that prolonged QTc interval may be considered to be a biomarker for detecting alterations in sympathovagal balance, especially cardiovagal dysfunction in OH.
    PLoS ONE 09/2014; 9(9):e106417. DOI:10.1371/journal.pone.0106417 · 3.23 Impact Factor
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    • "Various measurements throughout the day, including before and after meals, after medication, and before bed, or ambulatory blood pressure monitoring and measurements on different days, may be needed for patients with symptoms but normal blood pressure, or for differentiating between OH and postprandial hypotension (Feldstein & Weder, 2012; Gupta & Lipsitz, 2007). For those with unexplained recurrent syncope or suspected of neurocardiogenic syncope, OH can be diagnosed when a head-up tilt test is positive to an angle between 60 • and 80 • while standing for 3 min (Figueroa et al., 2010; Grubb, 2005; Moya et al., 2009; Vetta et al., 2009). In addition, measuring heart rate before and after standing is helpful; an increase in heart rate of less than 10 beats/min indicates baroreflex impairment, while an increase of more than 20 beats/min implies volume deficiency or orthostatic intolerance (Gupta & Lipsitz, 2007). "
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    ABSTRACT: To enhance awareness of orthostatic hypotension (OH) in older populations, and guide primary care nurse practitioners (NPs) in the assessment and management of patients with OH. Electronic data collection was conducted on studies and reviews that were published between 2005 and 2012 in English, and contained information related to the purpose of this article from following databases: PubMed, Scopus, and MEDLINE. OH is a syndrome that is accompanied by unfavorable symptoms such as dizziness, and headaches and can impede the individual's daily activities and quality of life. The prevalence of OH is higher in older people because of comorbidities, polypharmacy, and physiological changes that occur with aging. OH is diagnosed with serial blood pressure measurements and the primary goal of management is to relieve unfavorable symptoms and enhance patient safety. Pharmacological management is considered when nonpharmacological interventions fail. OH is not a problem to be taken lightly as it is highly related to the risk of falling and cardiovascular problems, as well as increasing morbidity and mortality rates. NPs can contribute to improving the quality of life for older adults and reducing adverse consequences by understanding OH and adequately managing it.
    Journal of the American Association of Nurse Practitioners 09/2013; 25(9):451-8. DOI:10.1002/2327-6924.12026
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    • "The key strategy in promoting postoperative recovery is early ambulation after surgery [1]. However, early ambulation is difficult when there is orthostatic intolerance, which is characterized by having difficulty maintaining a sitting and/or upright position due to symptoms from cerebral hypoperfusion, such as dizziness, nausea, feeling of heat, blurred vision, and syncope [2]. In the sitting and/or upright position, gravity pulls blood towards the abdomen or legs, and it is easy for postoperative patients to have a reduced central blood volume when maintaining a sitting and/or upright position due to an insufficient amount of fluids or blood during surgery. "
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    ABSTRACT: Opioid analgesics are widely used to reduce postoperative pain and to enhance post-operative recovery. However, orthostatic intolerance (OI) induced by opioid containing intravenous patient controlled analgesia (IPCA) may hinder postoperative recovery. This study investigated factors that affect OI in patients receiving IPCA for postoperative pain control. OI was instantly evaluated at the time of first ambulation in 175 patients taking opioid containing IPCA after open and laparoscopic subtotal gastrectomies. Patients were classified as having OI if they experienced dizziness, nausea/vomiting, blurred vision, headache, somnolence and syncope. Factors contributing to OI were assessed with logistic regression analysis. Out of 175 patients, 61 (52.6%) male and 44 (74.6%) female patients experienced OI at the time of first ambulation. The frequency of OI related symptoms were dizziness (97, 55.4%), nausea (46, 26.3%), headache (9, 5.1%), blurred vision (3, 1.7%) and vomiting (2, 1.1%). Significant risk factors for OI were gender (P=0.002) and total amount of opioids administered (P=0.033). The incidence of OI is significantly higher in male than in female patients and is influenced by the opioid dose.
    The Korean journal of pain 07/2013; 26(3):277-85. DOI:10.3344/kjp.2013.26.3.277
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