Putting it together: a new treatment algorithm for vasovagal syncope and related disorders

Youth with Chronic Pain and Postural Orthostatic Tachycardia Syndrome (POTS): Treatment Mediators of Improvement in Functional Disability

Intensive pain rehabilitation programs are effective in increasing functioning for youth with chronic pain (CP). However, the utility of such programs for youth with CP and co-morbid postural orthostatic tachycardia syndrome (POTS) is rarely examined. In addition, studies examining mediators of treatment for CP are sparse. This paper compares treatment outcomes for youth with CP (n = 117) and youth with CP + POTS (n = 118). Additionally, depression and pain catastrophizing were tested as potential mediators of treatment effects. Significant treatment improvements were found for functional disability, depression, pain catastrophizing, and perceived pain intensity but with no differences between groups. Improvements in depressed mood, pain catastrophizing (helplessness subscale), and pain severity partially mediated functioning improvement. Pain severity was not a significant mediator in the CP + POTS group. We concluded that depression and pain catastrophizing, especially the helplessness domain, can impact functioning improvement in adolescents with CP and POTS and are particularly important to target in treatment.

Pyridostigmine in the Treatment of Orthostatic Intolerance

Objective:

To review the efficacy of pyridostigmine bromide for the treatment of orthostatic intolerance.

Data Sources:

MEDLINE and International Pharmaceutical Abstracts were searched (1966–December 2006) using the terms pyridostigmine, acetylcholinesterase inhibitor, orthostatic intolerance, orthostatic hypotension, neurogenic orthostatic hypotension, postural tachycardia syndrome, tachycardia, and orthostatic tachycardia.

Study Selection and Data Extraction:

Pertinent English-language human clinical trials, case reports, and background material were evaluated for safety and efficacy data. The references of reviewed articles were reviewed and used to identify additional sources.

Data Synthesis:

Pyridostigmine bromide has been associated with improved baroreceptor sensitivity and presents a novel approach to treatment of orthostatic intolerance. Four single-dose trials and a follow-up survey encompassing a total of 106 patients were identified. One open-label and one placebo-controlled single-dose trial in patients with neurogenic orthostatic hypotension (NOH) found statistically significant improvement in standing diastolic blood pressures (DBP). Absolute improvements in standing DBP were 3.7 and 6.4 mm Hg in the open-label and controlled trials, respectively. Long-term data consist of a single survey of patients receiving open-label pyridostigmine bromide. Twenty-nine percent of patients who initiated maintenance pyridostigmine bromide discontinued therapy. Concomitant NOH medications were taken by 75% of patients, and 85% of patients reported receiving benefit from pyridostigmine bromide. When evaluated for postural tachycardia syndrome, pyridostigmine bromide significantly reduced standing heart rate (10%). Pyridostigmine bromide significantly reduced symptom scores when compared with baseline but not placebo. The majority of patients included in these trials did not have supine hypertension.

Conclusions:

Single doses of pyridostigmine bromide produced modest but statistically significant improvements in hemodynamic measurements. At this time, long-term data are insufficient to support recommending the routine use of pyridostigmine bromide for treatment of orthostatic intolerance.

High diagnostic yield and accuracy of history, physical examination, and ECG in patients with transient loss of consciousness in FAST: the Fainting Assessment study

BACKGROUND

Transient loss of consciousness (TLOC) is a common clinical problem.

OBJECTIVE

The aim of this study was to assess the yield and accuracy of the initial evaluation, consisting of standardized history, physical examination, and ECG performed by attending physicians in patients with TLOC.

METHODS AND RESULTS

Five hundred and three adult patients (mean age 53 +/- 19; 56% male) presenting with TLOC to the Academic Medical Center Amsterdam between February 2000 and May 2002 were included in this study. After initial evaluation, the physician made a certain, a highly likely (>80% certain), or no initial diagnosis. Initially undiagnosed patients received additional cardiological testing, additional history taking, and autonomic function tests. After 2 years of follow-up, an expert committee determined the final diagnoses. Two-year follow-up was obtained in 99% of the patients. The yield of certain diagnoses after the initial evaluation was 24%, increasing to 63% after including the highly likely diagnoses. The diagnostic accuracy of the initial certain diagnoses was 93% (95% CI 87-97%), decreasing to 88% (95% CI 84-91%) after inclusion of the initial highly likely diagnoses.

CONCLUSION

Attending physicians can make a diagnosis based on initial evaluation in 63% of patients with TLOC, with an overall diagnostic accuracy of 88%. The use of additional testing, beyond history, physical examination, and ECG can be avoided in many patients with TLOC.

Blood Volume Measurement as a Tool in Diagnosing Syncope

BACKGROUND

The cause of syncope remains unknown in 24% to 37% of cases even after standard diagnostic tests. Measuring blood volume may elucidate the mechanisms of syncope in the individual patient and prove helpful in determining optimal therapy. This report includes the largest set of blood volume measurements performed in syncope patients to date.

METHODS

We performed radioisotopic blood volume measurement (Daxor BVA-100) on 539 patients who presented to our center with syncope/presyncope of unclear etiology. There were 202 men and 337 women, ages 16 to 88 years; many were receiving treatment at the time they were referred to our center. We also measured blood pressure, heart rate, and cardiac index before and during tilt, with complete data available for 411 patients.

RESULTS

Blood volume derangements ranged from -32% to +116% deviation from normal. Hematocrit could not be used to predict volume status. Volume depletion was found in 241 (44.7%) patients and volume expansion was found in 63 (11.7%). Blood pressure, heart rate, and cardiac index before and during tilt did not correlate with any component of blood volume and could not be used to predict volume status.

CONCLUSIONS

Syncope patients are heterogeneous with respect to blood volume, and blood volume derangements are common and are not identified through tilt table testing. Empirically prescribed pharmacological treatment for syncope is frequently inappropriate. Blood volume measurement should be included in syncope diagnosis.

Hipertensión arterial episódica asociada al síndrome de taquicardia postural ortostática

We report the case of a 17-year-old woman who presented to the emergency department on several occasions due to palpitations, tachycardia, syncope, short spells of dizziness and light-headedness with complete spontaneous recovery, and hypertension. The patient had been evaluated by several specialists, and multiple complementary examinations had revealed no abnormalities that could explain the symptoms. Due to suspicion of orthostatic intolerance or postural orthostatic tachycardia syndrome with hypertension, the patient underwent a 60-degree tilt table test, which confirmed the diagnosis. The patient was successfully treated with bisoprolol. The physiopathological mechanisms, diagnosis, and treatment of this syndrome are reviewed.

A randomised prospective comparison of three protocols for head-up tilt testing and carotid sinus massage

INTRODUCTION

Head-up tilt testing is an important tool in the diagnosis of syncope. Several different protocols are in use. This study aimed to compare three different protocols in an unselected population of patients with recurrent unexplained syncope and to assess long-term outcome using conventional tilt-directed management or implantable loop recorder (Reveal Plus)-directed management, allowing evaluation of the sensitivity and specificity of the technique.

METHODS

Patients with recurrent unexplained syncope were randomized to one of three tilt protocols: Drug-free--70 degree tilt, 45 min, CSM at 5 and 45 min. GTN--70 degree tilt, 35 min, CSM at 5 min, 400 microg of glyceryl trinitrate spray administered sublingually at 20 min. Adenosine--70 degree tilt, 5 min, CSM when blood pressure is stable in upright position, adenosine bonus at 150 microg/kg after CSM. Tilts were terminated at the onset of syncope, when systolic BP reached 60 mm Hg, or in the presence of prolonged hypotension (> 3 min systolic BP < 80 mm Hg). Appropriate therapies were commenced according to the result of the tilt test. All patients without a definite indication for immediate cardiac pacing (asystolic tilt) were randomized to conventional management or ILR implantation. Recurrent syncopal events were compared to tilt outcome, allowing estimation of sensitivity and specificity.

RESULTS

Of 214 patients, aged 68+/-18 years, 55% were female, with a median of three previous syncopes. 13 patients received pacemakers due to asystolic syncope during tilt testing. The proportion of VASIS classification diagnoses was similar with each protocol; however more positive diagnoses resulted from the GTN protocol (p=0.0013). 47% of patients achieved a diagnosis with tilt testing. We were able to correlate a subsequent spontaneous syncope to tilt result in 36 patients (18%). Heart rate during a spontaneous event was similar to that obtained during tilt testing (+/- 10%) in 55% of cases. Sensitivities for combined protocols, adenosine, GTN, and drug-free protocols were 50%, 50%, 100%, and 21%, respectively. Specificities were 85%, 100%, 75%, and 71%, respectively.

CONCLUSIONS

A high diagnosis rate for unexplained syncope can be achieved with tilt testing. The GTN protocol resulted in significantly more diagnoses than the other compared protocols with good sensitivity and adequate specificity. Sensitivity of the drug-free tilt test was lower than drug-augmented tilt testing.

Long-term survival of Japanese patients transported to an emergency department because of syncope

STUDY OBJECTIVE

Cardiovascular disease mortality is affected by ethnic differences and is lower in Japan than in Western countries. Although patients with cardiac syncope have significantly higher mortality than patients with noncardiac syncope in Western countries, no such phenomenon has been described in Japan. The aim of this study is to clarify the long-term mortality of patients with syncope who are brought to an emergency department (ED) in Japan.

METHODS

This retrospective observational study was conducted on patients treated in the ED of Keio University Hospital in Tokyo. Nine hundred twelve consecutive patients who presented with syncope were identified. The patients were classified into 2 groups according to the cause of syncope: cardiac syncope and noncardiac syncope. Follow-up information about mortality was obtained from mailed questionnaires and medical records. Mortality data were analyzed using the actuarial life-table method and a Cox proportional hazards model.

RESULTS

Follow-up information was obtained for 715 patients. The median follow-up period was 38 months, during which 63 patients died. At 5 years, the 23.1% (95% confidence interval [CI] 12.7% to 33.4%) mortality of the patients with cardiac syncope was significantly higher than the 8.2% (95% CI 5.5% to 10.9%) mortality of the patients with noncardiac syncope (P<.0001). The incidence of cardiac death among the patients with cardiac syncope was 17.2% (95% CI 7.8% to 26.5%) compared with 0.9% (95% CI 0% to 1.8%) in the noncardiac syncope group (P<.0001). Cardiac syncope was an independent predictor of overall mortality and cardiac mortality (relative risk 2.81 [95% CI 1.53 to 5.16], 18.74 [95% CI 5.90 to 59.52]).

CONCLUSION

Cardiac syncope is associated with higher mortality than noncardiac syncope in this Japanese patient population.

Syncope and orthostatic intolerance

Syncope and orthostatic intolerance remain common and significant clinical problems with many undocumented, misdiagnosed, or cryptogenic cases. Careful clinical assessment and application of advancing laboratory support can further improve diagnosis and treatment. Despite the depth of existing research into these common problems, many underlying mechanisms remain unproven.

Usefulness and safety of shortened head-up tilt testing potentiated with sublingual glyceryl trinitrate in older patients with recurrent unexplained syncope

OBJECTIVES

To evaluate the sensitivity and tolerability of shortened, glyceryl trinitrate (GTN)-potentiated, head-up tilt test (HUT) in patients older and younger than 65 with unexplained syncope and to compare the specificity of GTN-potentiated HUT (GTN-HUT) in older and younger controls.

DESIGN

Methodological study.

SETTING

Syncope units in secondary and tertiary hospitals.

PARTICIPANTS

Three hundred twenty-four consecutive patients with unexplained syncope (100 aged > or =65 (mean age +/- standard deviation 73 +/- 6; 35 men) and 224 aged <65 (41 +/- 15; 111 men)) and 64 controls (29 aged > or =65 (73 +/- 6; 13 men) and 35 aged <65 (42 +/- 13; 16 men)).

INTERVENTION

Patients and controls were tilted upright to 60 degrees for 20 minutes. If syncope did not occur, sublingual GTN (400 microg) was administered and 60 degrees HUT was continued for 15 minutes. Responses were classified as positive, negative, or exaggerated (slow decrease in blood pressure with a slight decrease in heart rate after GTN).

MEASUREMENTS

Electrocardiogram and arterial pressure were monitored continuously.

RESULTS

GTN-HUT was positive in 60% and 66% (NS), negative in 29% and 33% (NS), and exaggerated in 11% and 1% (P <.001) of older and younger patients, respectively. In older and younger controls, the GTN-HUT was negative in 70% and 86% and exaggerated in 28% and 9% of cases, respectively, (P <.05). The overall specificity (considering as negative also the exaggerated responses) was 97% in older and 94% in younger subjects. No patient or control experienced serious side effects.

CONCLUSION

The shortened GTN-HUT provides satisfactory positivity rate and specificity in older patients. This test may be considered as a diagnostic tool in assessing recurrent unexplained syncope in older patients.

Strategy for the management of vasovagal syncope

The disorders of autonomic control associated with orthostatic intolerance are a diverse group of syndromes that can result in syncope and near-syncope. A basic understanding of the pathophysiology of these disorders is essential to diagnosis and proper treatment. It is especially important to recognise the difference between the effect of prolonged upright posture on a failing autonomic nervous system (a hyposensitive or dysautonomic response) and the vasovagal response (which may be a hypersensitive response). Vasovagal syncope is the most common abnormal response to upright posture and occurs in all age groups. The advent of tilt table testing has helped define a population with an objective finding during provocative testing that has enabled researchers to study the mechanism of vasovagal syncope and to evaluate the efficacy of treatments. In most patients, vasovagal syncope occurs infrequently and only under exceptional circumstances and treatment is not needed. Treatment may be indicated in patients with recurrent syncope or with syncope that has been associated with physical injury or potential occupational hazard. Based on study data, patients with vasovagal syncope can now be risk stratified into a high-risk group likely to have recurrent syncope and a low-risk group. Many patients with vasovagal syncope can be effectively treated with education, reassurance and a simple increase in dietary salt and fluid intake. In others, treatment involves removal or avoidance of agents that predispose to hypotension or dehydration. However, when these measures fail to prevent the recurrence of symptoms, pharmacological therapy is usually recommended. Although many pharmacological agents have been proposed and/or demonstrated to be effective based on nonrandomised clinical trials, there is a remarkable absence of data from large prospective clinical trials. Data from randomised placebo-controlled studies support the efficacy of beta-blockers, midodrine, serotonin reuptake inhibitors and ACE inhibitors. There is also considerable clinical experience and a consensus suggesting that fludrocortisone is effective. Encouraging new data suggest that a programme involving tilt training can effectively prevent vasovagal syncope. For patients with recurrent vasovagal syncope that is refractory to these treatments, implantation of a permanent pacemaker with specialised sensing/pacing algorithms appears to be effective. A number of larger clinical trials are underway which should help further define the efficacy of a number of different treatments for vasovagal syncope.

Orthostatic hypotension, 2001

Upright posture requires rapid and effective circulatory and neurologic compensations to maintain blood pressure and consciousness. Although it has been recognized over the past 100 years or more that the act of standing may cause hypotension in patients with autonomic dysfunction, only recently several of the pathophysiologic mechanisms resulting in orthostatic intolerance have been discovered. In patients with orthostatic hypotension, failure of reflex vasoconstriction causes pooling of blood in the legs during standing. Not everyone with a postural blood pressure drop requires treatment, nor does everyone with posturally induced symptoms have orthostatic hypotension. This review will discuss current knowledge of a broad, heterogeneous group of disturbances in the autonomic nervous system, each of which is manifested by hypotension, orthostatic intolerance, and often syncope.

Medical therapy of neurocardiogenic syncope

Neurocardiogenic syncope, alternatively called vasovagal, vasodepressor, or neurally mediated syncope, is a clinical syndrome faced by many clinicians. Its pathophysiology is complicated and not fully understood. Multiple pharmacologic therapies have been evaluated, with no clear ideal agent. Decisions regarding tilt-table testing, selection of pharmacotherapy, and assessment of drug efficacy are not straightforward. This article attempts to assess these issues.

Dysautonomia and neurocardiogenic syncope

Syncope in childhood is a common problem. In most children, syncope is benign, secondary to a disturbance in autonomic control of heart rate and blood pressure. It is increasingly evident that neurally mediated syncope is a heterogeneous group of conditions, necessitating a reclassification of autonomic disorders. New entities, such as postural orthostatic tachycardia and cerebral vasoconstrictive syncope, are recognized. The key to the diagnosis of syncope is a careful history. Tilt testing can be useful when the history is unclear. Unfortunately tilt test protocols vary, affecting specificity and sensitivity. The mainstay of therapy is reassurance. If symptoms are troublesome, Fludrocortisone and B-blockers remain the favored drugs. The efficacy of Midodrine and Serotonin Uptake Inhibitors is currently under review. Cardiac pacing is effective for those patients with severe episodes and demonstrated asystole. It is not known whether pacing would be effective for the majority who have neurally mediated syncope without significant bradycardia.

Vasodepressor Syncope

Neurocardiogenic syncope is a common disorder affecting various individuals of different ages with a wide variety of circumstances and comorbid conditions. Although a large amount of data is available regarding evaluation and treatment options, there is still sufficient latitude for the physician to exercise clinical judgment. We summarize current opinions on treatment here and also add some of our own bias regarding how to manage such patients. The vast majority of patients can be assessed by a reduction of symptomatic episodes with therapy. In all patients, careful follow-up should be made after initiating therapy. Not all patients will obtain complete resolution of symptoms. If episodes of complete syncope are reduced to infrequent dizzy spells, however, this may be satisfactory. In other patients, abrupt syncope may be converted to spells with a sufficient prodromal warning for the patient to take evasive action.

Indications, methodology, and classification of results of tilt-table testing

Tilt-table testing has become an important part of the evaluation of patients with unexplained syncope, although not every patient with vasovagal syncope requires it. Studies have attested to the effectiveness of the technique for providing direct diagnostic evidence of a patient's susceptibility to vasovagal syncope. This article reviews the need for tilt-table testing and the recommended methods for performing a test. In addition, a detailed classification of the hemodynamic patterns of collapse displayed over the course of a tilt-table study is provided. These distinctive collapse patterns document the evolution of a syncopal event and are particularly important to identify because they can influence the selection of therapy.