Prospective randomized study comparing permanent pacing with rate drop response and closed loop stimulation in patients with vasovagal syncope where permanent pacing is indicated and selected as the appropriate treatment option.

BACKGROUND: Pacing for vasovagal syncope is established. Two pacing algorithms are available. The rate-drop-response (RDR-Medtronic) is triggered by falling heart rate acting with modified rate-hysteresis. The closed loop stimulation or system (CLS-Biotronik) is triggered by impedance changes in the right ventricle reflecting falling volume and rising contractility. These are very different physiologically. Both algorithms carry favorable reports in clinical use. METHODS: A randomized-controlled superiority trial is proposed to compare the two algorithms for the control of vasovagal syncope in patients for whom pacing is indicated by current guidelines in North America and Europe. Available recent evidence may be seen as supporting superiority of CLS. No comparison between the two algorithms has been made. In this trial, patients will be centrally randomized to one or other algorithm on a 1:1 basis. Two-hundred-seventy-six patients in each group will be recruited. Sample size is determined using a confidence interval of 95%, a power of 90%, and a drop-out rate of 10% to detect an 11% difference between CLS and RDR. Recurrent symptom comparison will be made by an independent committee. The Co-primary endpoints will be recurrent syncope burden compared with that in 24-months preimplant, and occurrence of syncope in 24-months follow-up. Each outcome will be compared between the two algorithms. Secondary endpoints will be program and drug therapy changes over 24-months follow-up and quality of life by questionnaire at baseline,1 and 2 years. RESULTS AND CONCLUSIONS: These are anticipated to clarify the device algorithm choice and, therefore, to improve patient care.

Dysautonomia, Hypermobility Spectrum Disorders and Mast Cell Activation Syndrome as Migraine Comorbidities.

PURPOSE OF REVIEW: Dysautonomia refers to the dysfunction of the autonomic nervous system and encompasses a wide variety of autonomic symptoms and disorders. The most common autonomic disorders are postural orthostatic tachycardia syndrome (POTS), neurocardiogenic syncope (NCS), and orthostatic hypotension (OH), which may be encountered in clinical practice as part of a triad of dysautonomia, hypermobility spectrum disorders (HSD), and mast cell activation syndrome (MCAS). Migraine is one of the most common comorbidities of POTS, HSD, and MCAS; conversely, these conditions are also prevalent in patients with migraine, especially in those with multiple systemic symptoms, such as chronic dizziness, lightheadedness, orthostatic intolerance, joint pain, and allergic symptoms. Diagnostic criteria, pathophysiologic mechanisms, and therapeutic considerations in patients with migraine and comorbid dysautonomia, HSD, and MCAS are reviewed. RECENT FINDINGS: Numerous studies indicate a significant overlap and shared pathophysiology in migraine, dysautonomia, HSD, and MCAS. In clinical setting, dysautonomia, HSD, and MCAS may present a diagnostic and therapeutic challenge in patients with migraine and require a high index of suspicion on the part of the neurologist. Diagnosis and treatment of these complex disorders in patients with migraine is essential to comprehensive patient-centric care, reduced symptom burden, and improved functional impairment secondary to both migraine and comorbidities.

Ganglionated plexi ablation in the right atrium for the treatment of cardioinhibitory syncope.

Neurocardiogenic syncope, also called vasovagal syncope, represents one of the clinical manifestations of neurally mediated syncopal syndrome. Generally, the prognosis of the cardioinhibitory form of neurocardiogenic syncope is good, but quality of life is seriously compromised in patients who experience severe forms. Drug therapy has not achieved good clinical results and very heterogeneous data come from studies regarding permanent cardiac pacing. In this scenario, the ganglionated plexi ablation has been proposed as an effective and safe method in patients with cardioinhibitory neurocardiogenic syncope, especially in young patients in order to avoid or prolong, as much as possible, the timing of definitive cardiac pacing. Certainly, making this procedure less extensive and limiting the ablation in the right atrium (avoiding the potential complications of a left atrial approach) and at level of anatomical regions of the most important ganglionated plexy, considered 'gateway' of the sino-atrial and atrio-ventricular node function (through the recognition of specific endocardial potentials), could be very advantageous in this clinical scenario. Finally, randomized, multicentre, clinical trials on a large population are needed to better understand which is the best ablation treatment (right-only or bi-atrial) and provide evidence for syncope guidelines.

Vasovagal Syncope during Office Hysteroscopy-A Frequently Overlooked Unpleasant Complication.

Due to technological advancements in miniaturization of instruments and improved optics, the number of office hysteroscopic procedures has increased over time. Office hysteroscopy is preferred due to avoidance of general anesthesia and decreased overall cost. Vasovagal syncope has been implied as the most common complication. Vasovagal syncope is associated with inappropriate reflex vasodilation and bradycardia in the setting of an acute malfunction between the autonomic nervous system and the cardiovascular system; however, there is no mortality associated with vasovagal syncope. A management strategy for acute vasovagal reflex during office hysteroscopy is proposed in order to manage this common complication.

Usefulness of post-procedural heart rate response to predict syncope recurrence or positive head up tilt table testing after cardioneuroablation.

AIMS: Previous reports have suggested that cardioneuroablation (CNA) can be effective in reducing syncopal recurrences in patients with vasovagal syncope (VVS). This study assessed the efficacy of CNA in preventing a positive response to head-up tilt testing (HUT). METHODS AND RESULTS: This is a single-centre retrospective study reviewing prospectively collected data. Fifty-one consecutive patients with VVS were included in the study. After confirmation of >3 s asystole on HUT, all patients underwent CNA. Head-up tilt testing was repeated 1 month after CNA. The main outcome measures were recurrence of syncope episode and positive response on HUT. During a median follow-up period of 11 months (interquartile range 3-27 months), all but 3 (5.8%) of 51 patients were free of syncope. Repeated HUTs were negative in 44 (86.2%) patients. When patients with recurrent syncope were excluded, vasodepressor response was seen in three cases and cardioinhibitory response in one case, respectively. Cardioneuroablation caused significant and durable shortening of RR interval in all cases. This effect was significantly higher in patients without positive HUT responses. CONCLUSION: This pilot study shows that CNA can effectively prevent recurrent syncopal episodes in patients with refractory VVS. Head-up tilt testing seems as a valuable diagnostic tool not only to select suitable candidates and but also to evaluate success of CNA.

Chronic Fatigue Syndrome: From Chronic Fatigue to More Specific Syndromes.

In the last decade, a group of chronic disorders associated with fatigue (CDAF) emerged as the leading cause of chronic fatigue, chronic pain, and functional impairment, all of which have been often labeled in clinical practice as chronic fatigue syndrome (CFS) or fibromyalgia. While these chronic disorders arise from various pathophysiologic mechanisms, a shared autoimmune or immune-mediated etiology could shift the focus from symptomatic treatment of fatigue and pain to targeted immunomodulatory and biological therapy. A clinical paradigm shift is necessary to reevaluate CFS and fibromyalgia diagnoses and its relationship to the CDAF entities, which would ultimately lead to a change in diagnostic and therapeutic algorithm for patients with chronic fatigue and chronic pain. Rather than uniformly apply the diagnoses of CFS or fibromyalgia to any patient presenting with unexplained chronic fatigue or chronic pain, it may be more beneficial and therapeutically effective to stratify these patients into more specific diagnoses in the CDAF group.

Blood Pressure Responses to Endovascular Stimulation: A Potential Therapy for Autonomic Disorders With Vasodilatation.

BACKGROUND: We have previously shown that sympathetic ganglia stimulation via the renal vein rapidly increases blood pressure. This study further investigated the optimal target sites and effective energy levels for stimulation of the renal vasculatures and nearby sympathetic ganglia for rapid increase in blood pressure. METHODS: The pre-study protocol for endovascular stimulations included 2 minutes of stimulation (1-150 V and 10 pulses per second) and at least 2 minutes of rest during poststimulation. If blood pressure and/or heart rate were changed during the stimulation, time to return to baseline was allowed prior to the next stimulation. RESULTS: In 11 acute canine studies, we performed 85 renal artery, 30 renal vein, and 8 hepatic vasculature stimulations. The mean arterial pressure (MAP) rapidly increased during stimulation of renal artery (95 ± 18 mmHg vs. 103 ± 15 mmHg; P < 0.0001), renal vein (90 ± 16 mmHg vs. 102 ± 20 mmHg; P = 0.001), and hepatic vasculatures (74 ± 8 mmHg vs. 82 ± 11 mmHg; P = 0.04). Predictors of a significant increase in MAP were energy >10 V focused on the left renal artery, bilateral renal arteries, and bilateral renal veins (especially the mid segment). Overall, heart rate was unchanged, but muscle fasciculation was observed in 22.0% with an output >10 V (range 15-150 V). Analysis after excluding the stimulations that resulted in fasciculation yielded similar results to the main findings. CONCLUSIONS: Stimulation of intra-abdominal vasculatures promptly increased the MAP and thus may be a potential treatment option for hypotension in autonomic disorders. Predictors of optimal stimulation include energy delivery and the site of stimulation (for the renal vasculatures), which informs the design of subsequent research.

Genome-Wide Association Study of Copy Number Variations in Patients with Familial Neurocardiogenic Syncope.

Neurocardiogenic syncope (NCS) is the most frequent type of syncope characterized by a self-limited episode of systemic hypotension. In this study, we conducted the first genome-wide association study testing copy number variations for association with NCS. Study population consisted of 107 consecutive patients with recurrent syncope and positive head-up tilt table testing. Four families with NCS were selected for CNV analysis. Affymetrix GeneChip(®) SNP 6.0 array was used for CNV analysis. Data and statistical analysis were performed with Affymetrix genotyping console 4.0 and GraphPad Prism v6. Positive family history of NCS was present in 19.6 % (n = 21) in our study population (n = 107). Twenty-six CNV regions were found to be significantly altered in families with NCS (P < 0.05). Several CNVs were identified in families with NCS. Further studies comprising wider study population are required to determine the effect of these variations on NCS development.

[A case of swallow syncope]. / La syncope de déglutition : cas clinique.

Syncope accounts for nearly 5 % of the emergency intake causes. Swallow syncope is a rare form of cardio-neurogenic syncope. Less than a hundred cases were reported since its first description in the mid-18th century. We present the case of an 83-year-old patient with recurrent syncope occurring during meals. Telemetry monitoring revealed a severe bradycardia with complete AV block and a pause of 8 seconds. A dual chamber pacemaker was implanted and the syncopal episodes were abolished. We shall briefly review the diagnostic methods, mechanisms, and therapy of swallow syncope.

La syncope représente près de 5 % des causes d'admission aux urgences. La syncope de déglutition est une forme rare de syncope d'origine cardio-neurogénique : moins d'une centaine de cas ont été rapportés depuis sa première description au milieu du 18ème siècle. Nous décrivons le cas d'un patient de 83 ans qui présente, depuis plusieurs mois, des syncopes au cours des repas. L'exploration a mis en évidence un trouble du rythme de type bradycardie sévère avec un bloc auriculo-ventriculaire et une pause de plus de 8 secondes enregistrée lors de la surveillance télémétrique. L'implantation d'un pacemaker double chambre a permis de mettre fin aux épisodes syncopaux. Cet article fait le point sur les méthodes diagnostiques, les mécanismes et le traitement des syncopes de déglutition.

Relationship between Neurocardiogenic Syncope and Ventricular Repolarization.

BACKGROUND: We aimed to analyze ventricular repolarization in neurocardiogenic syncope (NCS) patients by using T-peak-T-end interval, T-peak-T-end/QT ratio, T-peak-T-end/QTc ratio and corrected QT interval (QTc), QT dispersion (QTd), QT index (QTI) and corrected QT interval index (QTcI) comparing with the corrected JT dispersion (JTcd), and corrected JT (JTc) and the corrected JT interval index (JTcI), by inspecting ventricular activation until termination of repolarization. These parameters are used as an index of potential ventricular arrhythmogenesis. METHODS: We have studied patients with head-up tilt table test (HUTT) (+) (33 patients; mean age: 28 ± 11 years) and HUTT (-) as control group (33 patients; mean age: 30 ± 11 years). In all patients, T-peak-T-end interval, T-peak-T-end/QT ratio, T-peak-T-end/QTc ratio, QT, QTd, QTI, QTc, QTcI, JTd, JTc, and JTcI were measured on electrocardiogram. RESULTS: The following parameters were statistically significant between groups: QTd (22.72 ± 17.54 msn; 11.21 ± 13.40 msn; P = 0.004), QTc (424.27 ± 33.75 msn; 403.66 ± 38.08 msn; P = 0.023), QTcI (114.09 ± 14, 29%; 106.71 ± 15.33%, P = 0.047), and QTI (100.72 ± 7.19%; 97.14 ± 7.13%, P = 0.046). Furthermore, T-peak-T-end interval was significantly prolonged in the study group (93.78 ± 20.27 msn; 81.21 ± 11.66 msn; P = 0.003). T-peak-T-end/QT ratio was significantly higher in the study group (0.24 ± 0.04 msn; 0.22 ± 0.04 msn; P = 0.030). T-peak-T-end/QTc ratio was significantly higher in the study group (0.22 ± 0.04 msn; 0.20 ± 0.03 msn; P = 0.015). The JTc and JTd were also significantly higher in the study group ([103.00 ± 9, 72%; 95.44 ± 10.26%, P = 0.003], [27.57 ± 16.01 msn; 10.45 ± 16.08 msn; P < 0.001], respectively). CONCLUSIONS: Electrocardiographic ventricular repolarization parameters including T-peak-T-end interval, T-peak-T-end/QT ratio, T-peak-T-end/QTc ratio, QTc, QTd, QTI, QTcI, JTc, JTd, and JTI are prolonged in NCS.

Transvenous stimulation of the renal sympathetic nerves increases systemic blood pressure: a potential new treatment option for neurocardiogenic syncope.

BACKGROUND: Neurocardiogenic syncope (NCS) is a common and sometimes debilitating disorder, with no consistently effective treatment. NCS is due to a combination of bradycardia and vasodilation leading to syncope. Although pacemaker devices have been tried in treating the bradycardic aspect of NCS, no device-based therapy exists to treat the coexistent vasodilation that occurs. The renal sympathetic innervation has been the target of denervation to treat hypertension. We hypothesized that stimulation of the renal sympathetic nerves can increase blood pressure and counteract vasodilation in NCS. METHODS AND RESULTS: High-frequency stimulation (800-900 pps, 10 V, 30-200 seconds) was performed using a quadripolar catheter in the renal vein of 7 dogs and 1 baboon. A significant increase in blood pressure (BP; mean [SD] systolic BP 117 [±28] vs. 128 [±33], diastolic BP 75 [±19] vs. 87 [±29] mmHg) was noted during the stimulation, which returned to baseline after cessation of stimulation. The mean increase in systolic and diastolic BP was 13.0 (±3.3) (P = 0.006) and 10.2 (±4.6) (P = 0.08), respectively. CONCLUSION: We report the first ever study of feasibility and safety of high-frequency electrical stimulation of the renal sympathetic innervation to increase BP in animal models. This has potential applications in the treatment of hypotensive states such as NCS.

Postural tachycardia syndrome (POTS) and other autonomic disorders in antiphospholipid (Hughes) syndrome (APS).

BACKGROUND: Antiphospholipid syndrome (APS) is an autoimmune hypercoagulable disorder that has been shown to cause a large number of cardiac and neurological manifestations. Two recent studies have demonstrated abnormalities in cardiovascular autonomic function testing in APS patients without other cardiovascular or autoimmune disease. However, an association between autonomic disorders such as postural tachycardia syndrome and APS has not previously been described. METHODS AND RESULTS: Data were obtained by retrospective chart review. We identified 15 patients who have been diagnosed with APS and an autonomic disorder. The median age of the patients at the time of data analysis was 39 years. The autonomic disorders seen in these patients included postural tachycardia syndrome, neurocardiogenic syncope and orthostatic hypotension. The majority of patients (14/15) were female and the majority (14/15) had non-thrombotic neurological manifestations of APS, most commonly migraine, memory loss and balance disorder. Many also had livedo reticularis (11/15) and Raynaud's phenomenon (nine of 15). In some patients, the autonomic manifestations improved with anticoagulation and/or anti-platelet therapy; in others they did not. Two patients with postural tachycardia syndrome who failed to improve with the usual treatment of APS have been treated with intravenous immunoglobulin with significant improvement in their autonomic symptoms. CONCLUSION: We believe that autonomic disorders in APS may represent an important clinical association with significant implications for treatment.

Atrial electromechanical conduction delay in patients with neurocardiogenic syncope.

AIM: We aimed to investigate the presence of atrial electromechanical conduction delay in patients with neurocardiogenic syncope, which was diagnosed with head-up tilt table test (HUTT). MATERIALS AND METHODS: A total of 29 patients (mean age: 30.6 ± 15.9 years) with vasovagal syncope, as diagnosed by HUTT, and 23 healthy control subjects (mean age: 34.7 ± 16.3 years) with a negative HUTT were enrolled to the study. Atrial electromechanical conduction delay was defined as the time elapsed from the beginning of the P wave in the electrogardiogram to the beginning of the Am wave in tissue Doppler. RESULTS: There was no statistically significant difference between the groups in terms of interatrial conduction delay, whereas the difference was significant with regard to the right intraatrial electromechanical conduction delay (P < 0.01) and the left intraatrial electromechanical conduction delay (P < 0.0001). There was a negative correlation between the left intraatrial electromechanical conduction delay and the right intraatrial electromechanical conduction delay (r = -0.486, P = 0.001), whereas a positive correlation was present with the interatrial electromechanical conduction delay (r = 0.507, P = 0.001). CONCLUSION: In this study, the tissue Doppler method revealed that there is left and right intraatrial electromechanical conduction delay in patients with vasovagal syncope. The impact and role of atrial conduction delay as a pathophysiological determinant should be confirmed in further studies.

Demonstrating new-onset or worsened sudomotor function post-COVID-19 on comparative analysis of autonomic function pre-and post-SARS-CoV-2 infection.

Background: Autonomic dysfunction including sudomotor abnormalities have been reported in association with SARS-CoV-2 infection. Objective: There are no previous studies that have compared autonomic function objectively in patients pre- and post- SARS-CoV-2 infection.We aimed to identify if SARS-CoV-2 virus is triggering and/or worsening dysautonomia by comparing autonomic function tests in a group of patients pre-and post-SARS-CoV-2 infection. Design/methods: Six participants were enrolled and divided into two groups. The first group of 4 participants reported worsened autonomic symptoms post-SARS-CoV-2 infection. These individuals had their first autonomic test prior to COVID-19 pandemic outbreak (July 2019-December 2019). Autonomic function testing was repeated in these participants, 6 months to 1-year post-SARS-CoV-2 infection (June 2021).The second group of 2 participants reported new-onset autonomic symptoms post-COVID-19 infection and were also tested within 6 months post-SARS-CoV-2 infection.All participants had mild COVID-19 infection per WHO criteria. They had no evidence of large fiber neuropathy as demonstrated by normal neurophysiological studies (EMG/NCS). They were all screened for known causes of autonomic dysfunction and without risk factors of hypertension/hyperlipidemia, thyroid dysfunction, diabetes/prediabetes, vitamin deficiencies, history of HIV, hepatitis, or syphilis, prior radiation or chemical exposure or evidence of monoclonal gammopathy, or autoimmune condition. Results: Participants were female (age: 21-37y) and all endorsed orthostatic intolerance (6/6). Gastrointestinal symptoms (⅚), new-onset paresthesias, (3/6), and sexual dysfunction (2/6) were reported. Parasympathetic autonomic function remained stable 6-months to 1-year post-COVID-19 infection and no parasympathetic dysfunction was demonstrated in participants with new-onset dysautonomia symptoms. Postural orthostatic tachycardia was noted in half of the patients, being observed in one patient pre- SARS-CoV-2 infection and persisting post-SARS-CoV-2 infection; while new-onset postural tachycardia was observed in 1/3rd of patients. Sympathetic cholinergic (sudomotor) dysfunction was demonstrated in ALL participants. Worsened, or new-onset, sudomotor dysfunction was demonstrated in those with mild or normal sudomotor function on pre-COVID-19 autonomic testing. Conclusions: Sympathetic adrenergic and cholinergic dysautonomia probably account for some of the symptoms of Long COVID-19. Sudomotor dysfunction was demonstrated as consistently worsened or new-sequelae to COVID-19 infection. COVID-19 may be responsible for triggering new-onset or worsened small-fiber neuropathy in this sample, supporting previously reported studies with similar findings. However, the findings in our study are preliminary, and studies with larger sample size are needed to confirm these observations.

Improved health-related quality of life after cardioneuroablation in patients with vasovagal syncope.

BACKGROUND: As the most common cause of syncope, vasovagal syncope (VVS) is mediated by parasympathetic overactivity and/or sympathetic withdrawal. Although catheter ablation of ganglionated plexi or cardioneuroablation has been used to treat VVS, its role in quality of life (QoL) has not been formally evaluated. The aim of this study was to demonstrate if this novel treatment results in improvement QoL of patients with VVS. METHODS: Twenty-seven consecutive patients (age: 34 ± 14 years, 51.8% male) with dominant cardioinhibitory type VVS were prospectively enrolled in the study. After confirmation of > 3 s asystole on head-up tilt testing (HUT), all patients underwent cardioneuroablation. ECGs were obtained prior to procedure and at 12-month follow-up visit. HUTs were repeated 1 month after cardioneuroablation procedures. QoL was assessed with the use of SF-36, EQ-5D, and EQ VAS questionnaires. RESULTS: ECG, HUT, and QoL data were available in all patients. At 12-month follow-up, heart rate on rest ECG significantly increased (from 74 ± 15 to 84 ± 14 bpm, p = 0.003). Repeated HUTs were negative in 23 (85.1%) patients. All of 27 patients remained free of syncope. QoL assessed by SF-36 score significantly improved in postprocedural follow-up (92 ± 9 and 96 ± 11, p = 0.016). Similarly, significant improvements in mobility, self-care, and usual activity domains of EQ-5D were observed (mean scores of 3.0 ± 1.5 and 2.1 ± 1.3, p < 0.001; 1.3 ± 0.9 and 1.2 ± 0.6, p = 0.041; 1.7 ± 1.0 and 1.4 ± 0.8 respectively). EQ-VAS score also improved significantly (39 ± 24 to 77 ± 18, p < 0.001). CONCLUSION: Our findings suggest that cardioneuroablation may be associated with intermediate term improvement in QoL in patients with VVS.

Prospective Evaluation of Autonomic Dysfunction in Post-Acute Sequela of COVID-19.

BACKGROUND: Patients with post-acute sequela of COVID-19 (PASC) often report symptoms of orthostatic intolerance and autonomic dysfunction. Numerous case reports link postural orthostatic tachycardia syndrome (POTS) to PASC. No prospective analysis has been performed. OBJECTIVES: This study performed head-up tilt table (HUTT) testing in symptomatic patients with PASC to evaluate for orthostatic intolerance suggestive of autonomic dysfunction. METHODS: We performed a prospective, observational evaluation of patients with PASC complaining of poor exertional tolerance, tachycardia with minimal activity or positional change, and palpitations. Exclusion criteria included pregnancy, pre-PASC autonomic dysfunction or syncope, or another potential explanation of PASC symptoms. All subjects underwent HUTT. RESULTS: Twenty-four patients with the described PASC symptoms were included. HUTT was performed a mean of 5.8 ± 3.5 months after symptom onset. Twenty-three of the 24 had orthostatic intolerance on HUTT, with 4 demonstrating POTS, 15 provoked orthostatic intolerance (POI) after nitroglycerin, 3 neurocardiogenic syncope, and 1 orthostatic hypotension. Compared with those with POTS, patients with POI described significantly earlier improvement of symptoms. CONCLUSIONS: This prospective evaluation of HUTT in patients with PASC revealed orthostatic intolerance on HUTT suggestive of autonomic dysfunction in nearly all subjects. Those with POI may be further along the path of clinical recovery than those demonstrating POTS.

Catheter ablation of right atrial ganglionated plexi to treat cardioinhibitory neurocardiogenic syncope: a long-term follow-up prospective study.

PURPOSE: Several reports have focused on biatrial ganglionated plexi (GP) transcatheter ablation to treat cardioinhibitory neurocardiogenic syncope (CNS). Considering that anatomical studies showed a significant number of GP in the right atrium (RA), we hypothesized that RA "cardioneuroablation" could be an effective treatment for CNS. METHODS: Eighteen consecutive patients (mean age: 36.9 ± 11.2 years) with severe CNS were submitted to transcatheter ablation of GPs in the RA alone using an anatomical approach. Head up tilt test evaluation was performed during the follow-up period at 6, 12, and 24 months and in case of significant symptoms, while heart rate variability parameters were evaluated at patients discharge at 1, 3, 6, 12, 24, and 36 months after ablation. RESULTS: At a mean follow-up of 34.1 ± 6.1 months, 3 (16.6%) patients experienced syncopal episodes and 5 patients (27.7%) only prodromal episodes. Syncopal and prodromal recurrences were significantly decreased both in overall population (P = 0.001) and in symptomatic patients after ablation (P = 0.003). Heart rate variability analysis showed the loss of autonomic balance secondary to a reincrease of sympathetic tone after the acute phase faster than vagal tone more evident at 12 months (LF/HF vs preablation, P < 0.001) and persistent until 24 months. Finally, a good correlation was observed between symptomatic events and the extension of RF lesions in supero-, middle-, and infero-posterior RA areas (r = 0.73, P = 0.03; r = 0.85, P = 0.02; r = 0.87, P = 0.004, respectively). CONCLUSIONS: Cardioneuroablation in the RA can be considered safe and an effective technique to treat CNS episodes.

Further Observations on the Use of Pacemakers in Patients with Postural Orthostatic Tachycardia Syndrome with Demonstrated Asystole.

A subgroup of postural orthostatic tachycardia syndrome (POTS) patients may also have features of neurocardiogenic syncope (NCS). Syncope and presyncope are predominant clinical features in this subgroup of patients. Asystole has been reported as the cause of some recurrent syncopal episodes following evaluation with an implantable loop recorder (ILR). We present our experience of pacing in a group of patients with POTS and NCS, which resulted in the complete elimination of syncope. We reviewed the charts of 500 patients at the University of Toledo Medical Center from 2003 to 2013 and identified 40 patients who were eligible for inclusion in this study. Patients were included in this study if they had clinical features of POTS and unusually frequent episodes of syncope. All study participants subsequently underwent ILR implantation. Forty patients, including 32 (80%) women, aged 33 ± 13 years were included in this study. All patients demonstrated prolonged asystole (> 6 seconds) or severe bradycardia (heart rate < 30 bpm) during their syncope. Ten patients demonstrated an asystole of more than 10 seconds and also had prolonged and convulsive syncope. All patients had abrupt syncope without any warning signs. All 40 patients underwent dual-chamber pacemaker implantation. Syncope was eliminated in all 40 patients following pacemaker implantation; however, they continued to experience orthostatic tachycardia. Our findings support that dual-chamber pacing may help to eliminate syncope in a subgroup of POTS patients with recurrent syncope and prolonged asystole on ILR.

Postural orthostatic tachycardia syndrome (POTS) and other autonomic disorders after COVID-19 infection: a case series of 20 patients.

OBJECTIVE: To describe clinical features, diagnostic findings, treatments, and outcomes in patients with new-onset postural orthostatic tachycardia syndrome (POTS) and other autonomic disorders following SARS-CoV-2 infection (COVID-19). METHODS: We retrospectively reviewed medical records for patients who presented with persistent neurologic and cardiovascular complaints between April and December 2020 following COVID-19 infection. RESULTS: Twenty patients (70% female) were included in this study.Fifteen had POTS, 3 had neurocardiogenic syncope, and 2 had orthostatic hypotension. Six patients had abnormalities on cardiac or pulmonary testing, and 4 had elevated autoimmune or inflammatory markers. All patients were treated with non-pharmacologic therapies, and most required pharmacologic therapies. Six to 8 months after COVID-19, 17 (85%) patients had residual autonomic symptoms, with 12 (60%) unable to return to work. CONCLUSIONS: POTS can follow COVID-19 in previously healthy patients. Appropriate diagnostic investigations and therapies are necessary to identify and treat autonomic dysfunction after COVID-19.