Creating a data dictionary for pediatric autonomic disorders.

PURPOSE: Whether evaluating patients clinically, documenting care in the electronic health record, performing research, or communicating with administrative agencies, the use of a common set of terms and definitions is vital to ensure appropriate use of language. At a 2017 meeting of the Pediatric Section of the American Autonomic Society, it was determined that an autonomic data dictionary comprising aspects of evaluation and management of pediatric patients with autonomic disorders would be an important resource for multiple stakeholders. METHODS: Our group created the list of terms for the dictionary. Definitions were prioritized to be obtained from established sources with which to harmonize. Some definitions needed mild modification from original sources. The next tier of sources included published consensus statements, followed by Internet sources. In the absence of appropriate sources, we created a definition. RESULTS: A total of 589 terms were listed and defined in the dictionary. Terms were organized by Signs/Symptoms, Triggers, Co-morbid Disorders, Family History, Medications, Medical Devices, Physical Examination Findings, Testing, and Diagnoses. CONCLUSION: Creation of this data dictionary becomes the foundation of future clinical care and investigative research in pediatric autonomic disorders, and can be used as a building block for a subsequent adult autonomic data dictionary.

Inappropriate sinus tachycardia: a review.

Inappropriate sinus tachycardia (IST) has been defined as a resting heart rate of >100 beats per minute and an average 24-hour heart rate >90 bpm with distressing symptoms resulting from the persistent tachycardia. IST is prevalent in 1% of the middle-aged population, mostly females. Rarely can elderly patients also present with IST. Possible mechanisms of IST include intrinsic sinus node abnormality, beta-adrenergic receptor stimulating autoantibody, beta-adrenergic receptor supersensitivity, muscarinic receptor autoantibody, or hyposensitivity, impaired baroreflex control, depressed efferent parasympathetic/vagal function, nociceptive stimulation, central autonomic overactivity, aberrant neurohumoral modulation, etc. Symptoms associated with IST are palpitations, chest pain, fatigue, shortness of breath, presyncope, and syncope. Despite these distressing symptoms, IST has not been associated with tachycardia-associated cardiomyopathy or increased major cardiovascular events. Various treatment options for patients with IST are ivabradine, beta-adrenergic blockers, calcium channel blockers, psychiatric evaluation, and exercise training. Although, endocardial radiofrequency ablation targeting the sinus node has been used as a treatment modality for otherwise treatment-refractory IST, the results have been dismal. The other modalities used for refractory IST treatment are endocardial modification of the sinus node using radiofrequency energy, combined endo and epicardial ablation of the sinus node, thoracoscopic epicardial ablation of the sinus node, sinus node sparing thoracoscopic and endocardial hybrid ablation. The goal of this review is to provide the readership with the pathophysiological basis of IST and its management options.

Management strategies for vasovagal syncope.

Vasovagal syncope (VVS) (or neurocardiogenic syncope) is a common clinical condition that is challenging to both physicians and patients alike. Severe episodes of recurrent syncope can result in physical injury as well as psychological distress. This article provides a brief overview of current management strategies and a detailed overview of therapeutic modalities such as closed loop stimulation (CLS) and cardioneuroablation (CNA).

Risks of adverse events in patients with orthostatic intolerance undergoing surgery with general anesthesia.

INTRODUCTION: Orthostatic intolerance (OI) is a group of disorders characterized by symptoms that occur upon standing and resolve with recumbence. Although well established but not widely recognized, these diagnoses may create uncertainty for clinicians dealing with a patient affected by OI and requiring a surgical procedure. OBJECTIVES: To determine the rate of intra- and postoperative major adverse events in patients with OI undergoing surgery with general anesthesia. METHODS: The study was a retrospective study of patients with orthostatic intolerance who underwent surgery requiring general anesthesia from 1 January 2000 to 31 December 2018. RESULTS: A total 171 patients with OI underwent 190 surgeries. In patients with POTS and orthostatic-induced VVS, there were no major significant adverse events. There was one episode of AVNRT in a patient with POTS and one episode of bradycardia secondary to vasovagal reflex in a patient with orthostatic-induced VVS. Moreover, there were 13 (6.8%) episodes of postoperative hypotension. However, the majority of these episodes were related to bleeding, volume depletion or sepsis. All cases of hypotension responded well to appropriate therapy. In patients with OH, the rate of postoperative major adverse cardiac events was 4.7%, and the 30-day mortality rate was 6.1%. This is not significantly different from the calculated risk for patients without OH. There were no myocardial infarctions or deaths at 30 days in patients with POTS or orthostatic-induced VVS. CONCLUSION: Patients with OI may not experience higher rates of perioperative complications compared with patients without OI syndromes.

Ivabradine in children with postural orthostatic tachycardia syndrome: a retrospective study.

BACKGROUND: Ivabradine is a unique medication that reduces the intrinsic heart rate by specifically blocking the inward funny current that controls the pacemaker activity of the sinus node. We conducted a retrospective cohort study to assess the efficacy of ivabradine in children suffering from postural orthostatic tachycardia syndrome. METHODS: A chart review was conducted of patients less than 18 years of age who were diagnosed with postural orthostatic tachycardia syndrome who had received ivabradine as treatment from January 2015 to February 2019 at our institution. Twenty-seven patients (25 females, 92.5%) were identified for the study. The outcomes which were assessed included a change in the severity and frequency of symptoms, heart rate, and blood pressure before and after starting ivabradine. RESULTS: There was an improvement in the symptoms of 18 (67%) out of 27 patients. The most notable symptom affected was syncope/presyncope with a reduction in 90%, followed by lightheadedness (85%) and fatigue (81%). The vital signs of the patients showed an overall significant lowering of the heart rate during sitting (89.7 ± 17.9 versus 73.2 ± 12.1; p-value <0.05) and standing (100.5 ± 18.1 versus 80.9 ± 10.1; p-value <0.05) without a significant change in the blood pressure. Two patients had visual disturbances (luminous phenomena). Severe bradycardia and excessive flushing were seen in two patients, respectively. Another one patient reported joint pain and fatigue. CONCLUSION: This study indicates that 67% of children treated with ivabradine report an improvement in symptoms.

Role of implantable loop recorders in patients with postural orthostatic tachycardia syndrome.

INTRODUCTION: We previously reported on a subgroup of postural orthostatic tachycardia syndrome (POTS) patients who may also have features of neurocardiogenic syncope as well. In this subgroup of patients, we found syncope and presyncope were predominant clinical features. To understand the mechanism of syncope in this subgroup, we identified 39 patients who underwent loop recorder insertion. METHODS: We reviewed charts of 450 patients who had POTS and syncope seen at the University of Toledo Medical Center from 2003 to 2017. Thirty-nine patients had at least four episodes of syncope in the last 6 months and were included for this study. All of these patients had a prior evaluation with a Holter and an event monitor which were inconclusive. RESULTS: Thirty-nine patients, 33 (85%) women, aged 20-46 years, were included in this study. All patients demonstrated prolonged asystole (>6 seconds) or severe bradycardia (heart rate < 30 beats/min) during their syncope on implantable loop recorder (IRL). Fifteen patients demonstrated an asystole of >10 seconds and also had prolonged and convulsive syncope. All patients had abrupt syncope without any warning sign. All patients underwent dual-chamber pacemaker implantation using a closed loop stimulation algorithm. Syncope were completely eliminated in all patients following pacemaker implantation; however, they continued to have orthostatic tachycardia. CONCLUSION: POTS patients with unusually frequent syncope should be considered for ILR implantation if other monitoring modalities like 48-hour Holter monitor or event recorder are inconclusive. ILR may identify a subgroup of POTS patients who may benefit from pacemaker implantations.

Utility of High-Output His Pacing during Difficult AV Node Ablation. An Underutilized Strategy.

Atrioventricular (AV) node ablation is a commonly performed procedure for patients with chronic drug refractory atrial fibrillation (AF) with episodes of rapid ventricular response. We report on a 72-year-old man who had difficulty managing chronic drug refractory AFs with frequent hospitalizations for rapid ventricular rate. The patient was taken to the electrophysiology laboratory for AV node ablation. Extensive mapping and localization techniques of the compact AV node and ablation in the region were unsuccessful. Subsequently, high-output His bundle pacing using 20 mA at 2 ms of output energy was performed in an attempt to localize the His bundle in areas where high-output pacing resulted in a narrower QRS complex. Further ablations in the areas where pacing produced a narrower QRS complex resulted in complete heart block. This case highlights the importance of using this simple pacing maneuver to achieve complete heart block in patients in whom standard strategies to localize and ablate the compact AV node are unsuccessful.

Carbohydrate-restricted diet and acute coronary syndrome: a case report and review of this conflicting and yet unknown association.

We describe a case of a young patient, motivated to follow a carbohydrate-restricted diet intake for 6 years, who presented with an acute myocardial infarction.

Postural orthostatic tachycardia syndrome: New concepts in pathophysiology and management.

Postural orthostatic tachycardia syndrome (POTS) is a common and therapeutically challenging condition affecting numerous people worldwide. Recent studies have begun to shed light on the pathophysiology of this disorder. At the same time, both non-pharmacologic and pharmacologic therapies have emerged that offer additional treatment options for those afflicted with this condition. This paper reviews new concepts in both the pathophysiology and management of POTS.

Use of methylphenidate in the treatment of patients suffering from refractory postural tachycardia syndrome.

Methylphenidate has been shown to be an effective therapy in patients with refractory neurocardiogenic syncope. However, the role of methylphenidate in patients suffering from postural orthostatic tachycardia (POTS) has not been reported. The study was approved by the institutional review board. A retrospective nonrandomized analysis was preformed on 24 patients evaluated at our autonomic center for POTS from 2003 to 2010. The diagnosis of POTS was based on patient history, physical examination, and response to head up tilt table testing. The mean follow-up period was 9 ± 3 months. The patients were included in the current study if they had a diagnosis of POTS with severe symptoms of orthostatic intolerance and were refractory to the commonly used medications. All of these patients were started on methylphenidate and the response to therapy was considered successful if it provided symptomatic relief. Twenty-four patients (age 28 ± 12, 20 women) met inclusion criterion for this study. The response to treatment was assed subjectively in each patient and was collected in a retrospective fashion from patient charts and physician communications. Four patients reported side effects in the form of nausea and 2 ultimately had to discontinue the treatment. Another 4 patients had a follow-up of less than 6 months. Thus, only 18 patients who received methylphenidate completed the follow-up of 6 months. Out of these 18 patients, 14 (77%) patients reported marked improvement in their symptoms. Nine out of 12 patients who had recurrent episodes of syncope reported no syncope at 6 months of follow-up. Fourteen (77%) patients reported marked improvement in their symptoms of fatigue and presyncope. Four patients continue to have symptoms of orthostatic intolerance and 3 continued to have recurrent episodes of syncope. Methylphenidate may be beneficial in patients with otherwise refractory postural tachycardia syndrome.

Use of octreotide in the treatment of refractory orthostatic intolerance.

There have been reports on the use of octreotide in patients with orthostatic hypotension, postural tachycardia syndrome, and orthostatic syncope. However, there are little if any data on the use of octreotide in patients who have failed multiple other medications. This study was a retrospective chart analysis and was approved by our Institutional Review Board. A total of 12 patients were identified for inclusion in this study. The diagnosis of orthostatic intolerance was based on patient history, physical examination, and response to Head Up Tilt Table testing. These patients had failed multiple medications and were ultimately treated with octreotide. In a retrospective chart review, we collected data, including demographic information, presenting symptoms, laboratory data, tilt-table response, standing heart rate, standing blood pressure before and after treatment (wherever available), and treatment outcomes. Twelve patients aged 33 ± 18 years, eight (66.7%) females, were found to have symptoms of refractory orthostatic intolerance and failed multiple regimens of medication and were ultimately treated with octreotide administration. Five patients (41.7%) had demonstrated a postural tachycardia syndrome pattern, five (41.7%) a neurocardiogenic, and two (16.6%) a dysautonomic response on a Head Up Tilt Table. Symptoms of syncope and orthostatic palpitations improved in six (50%) of the patients. Standing heart rate was significantly reduced after octreotide administration (80 ± 8 versus 108 ± 13; P < 0.05). The standing systolic blood pressure was increased after octreotide administration (107 ± 26 versus 116 ± 22). Three patients (25%) reported complete elimination of syncope, whereas another three had reduction in the frequency of their syncope. However, symptoms of fatigue improved only in two (29%) of the seven patients. Octreotide may improve symptoms in some patients with refractory orthostatic intolerance.

Initial experience with a technique for wound closure after cardiac device implantation designed to reduce infection and minimize tissue scar formation.

Infection is a well-recognized complication that can occur after the implantation of cardiac devices such as pacemakers and implantable cardioverter defibrillators (ICDs). Reported infection rates after new device implantation are reported to be around 1%, while infection rates after device generator replacements are higher with a reported average of up to 4-5% per year. Here we report our experience using a modified plastic surgical technique for cardiac device wound closure designed to both reduce infections and enhance cosmetic outcomes. Patients were recruited from among those individuals undergoing routine cardiac device implantation (either new or replacement) at our institution. A total of 124 patients were included in the study. There were 74 women and 48 men, mean age 58 ± 16 years. There were 74 new pacemaker implants and 27 pacemaker generator replacements. There were 17 new ICD generator implants and 6 ICD generator reimplants. Mean follow-up time was 15 ± 16 months. During the follow-up period, there have been no device infections nor any wound dehiscences observed. Each patient felt that the scar was cosmetically acceptable. Two patients developed mild rashes to the clear plastic adhesive that resolved after removal. The modified wound closure technique described above appears to minimize cardiac device wound infections while facilitating cosmetically acceptable wound scar formation.

Erythropoietin in the treatment of postural orthostatic tachycardia syndrome.

Erythropoietin has been reported to improve symptoms of orthostatic intolerance in patients suffering from orthostatic hypotension. Previous reports on the use of erythropoietin in patients with postural orthostatic tachycardia (POTS) have included only a very small number of patients. In the current study, we report on the use of erythropoietin in patients with refractory POTS. The study was approved by the institutional review board. A retrospective nonrandomized analysis was performed on 39 patients evaluated at our autonomic center for POTS from 2003 to 2010. The diagnosis of POTS was based on patient history, physical examination, and response to head-up tilt-table testing. The mean follow-up period was 6 months. The patients were included in the current study if they had a diagnosis of POTS with severe symptoms of orthostatic intolerance and were refractory to the commonly used medications. All these patients were started on erythropoietin, and the response to therapy was considered successful if it provided symptomatic relief. We screened 200 patients with POTS and found 39 patients (age 33 ± 12, 37 females) to be eligible for inclusion in the current study. The response to the treatment was assessed subjectively in each patient and was obtained in a retrospective fashion from patient charts and physician communications. Eight (21%) patients demonstrated no improvement in symptoms after administration of erythropoietin. Three (8%) patients showed an improvement in symptoms of orthostatic intolerance of <3 months. Twenty-seven (71%) patients demonstrated sustained improvement in their symptoms of orthostatic intolerance at the mean follow-up of 6 months. Erythropoietin significantly improved sitting diastolic blood pressure but had no effect on other hemodynamic parameters. In a select group of POTS patients who are refractory to commonly used medications, erythropoietin may help improve symptoms of orthostatic intolerance.

Post-reperfusion syndrome during renal transplantation: a retrospective study.

Post-reperfusion syndrome (PRS) is a serious, widely reported complication following the reperfusion of an ischemic tissue or organ. We sought to determine the prevalence, risk factors and short-term outcomes of PRS related renal transplantation. We conducted a retrospective, case-control study of patients undergoing renal transplantation between July 2006 and March 2008. Identification of PRS was based on a drop in mean arterial pressure by at least 15% within 5 minutes of donor kidney reperfusion. Of the 150 consecutive renal transplantations reviewed, 6 patients (4%) met criteria for post-reperfusion syndrome. Univariate analysis showed that an age over 60, diabetes mellitus, Asian race, and extended criteria donors increased the odds of developing PRS by 4.8 times (95% CI [1.2, 20]; P=.0338), 4.5 times (95% CI [1.11, 18.8]; P=.0378), 35.5 times (95% CI [3.94, 319.8]; P=0.0078) and 9.6 times (95% CI [1.19, 76.28] P=0.0115) respectively. Short term follow-up revealed increased graft failure rate within 6 months (6% vs. 16% P=0.0125) and almost twice the number of hospital days post-transplant in PRS cohorts (5.43 ± 2.29 vs. 10.8 ± 7.29 P=<0.0001). Despite limited reporting, PRS appears to be a relatively common complication of renal transplantation and is associated with increase morbidity.

Syncope as an initial manifestation of atypical lipomatous hypertrophy of the interatrial septum.

Lipomatous hypertrophy of the interatrial septum (LHIS) is an incidental echocardiographic abnormality characterized by dumb-bell configuration of the interatrial septum from excess fat deposition. We report a case of syncope in a patient with LHIS obstructing the superior vena cava at the right atrial junction.