Vasovagal Research Articles

Diagnostic and therapeutic challenges in vasovagal syncope - a case report and literature review

Diagnostic and therapeutic challenges in vasovagal syncope - a case report and literature review

Heart Rate Variability in Basketball: The Golden Nugget of Holistic Adaptation?

The main aim of this narrative review is to assess the existing body of scientific literature on heart rate variability (HRV) in relation to basketball, focusing on its use as a measure of internal load and vagal nerve responses. Monitoring HRV offers insights into the autonomic function and training-induced adaptations of basketball players. Various HRV measurement protocols, ranging from short-term to longer durations, can be conducted in different positions and conditions, such as rest, training, and sleep, to determine this key metric. Consistency and individualization in measurement protocols, responding to the athlete’s specific characteristics, is crucial for reliable HRV data and their interpretation. Studies on HRV in basketball have explored psychological adaptation, training effects, individual differences, recovery, and sleep quality. Biofeedback techniques show positive effects on HRV and anxiety reduction, potentially enhancing performance and stress management. The scientific literature on HRV in basketball could benefit from studies involving longer monitoring periods to identify significant trends and results related to training and recovery. Longitudinal HRV monitoring in teams with intense travel schedules could reveal the impact on athletes of all levels and ages, and, in this regard, individualized interpretation, considering the subjective recovery and fitness levels of athletes, is recommended to optimize training programs and performance. HRV provides insights into training and competitive loads, aiding in determining exercise intensities and training status. Additionally, HRV is linked to recovery and sleep quality, offering valuable information for optimizing player performance and well-being. Overall, HRV is a reliable tool for adjusting training programs to meet the specific needs of basketball players.

Unraveling autonomic cardiovascular control complexity during orthostatic stress: Insights from a mathematical model

Understanding cardiovascular control mediated by the autonomic system remains challenging due to its inherent complexity. Consequently, syndromes such as orthostatic intolerance continue to evoke debates regarding the underlying pathophysiological mechanisms. This study develops a comprehensive mathematical model simulating the control of the sympathetic branch of the cardiovascular system in individuals with normal and abnormal responses to the head-up-tilt test. We recruited four young women: one control, one with vasovagal syncope, one with orthostatic hypertension, and one with orthostatic hypotension, exposing them to an orthostatic head-up tilt test (HUTT) employing non-invasive methods to measure electrocardiography and continuous blood pressure.Our work encompasses a compartmental model formulated using a system of ordinary differential equations. Using heart rate as input, we predict blood pressure, flow, and volume in compartments representing the veins, arteries, heart, and the sympathetic branch of the baroreflex control system. The latter is modulated by high- and low-pressure baroreceptor afferents activated by changes in blood pressure induced by the HUTT. Sensitivity analysis, parameter subset selection, and optimization are employed to estimate patient-specific parameters associated with autonomic performance. The model has seven sensitive and identifiable parameters with significant physiological relevance that can serve as biomarkers for patient classification.Results show that the model can reproduce a spectrum of blood pressure responses successfully, fitting the trajectory displayed by the experimental data. The controller exhibits behavior that emulates the operation of the sympathetic system. These encouraging findings underscore the potential of computational methods in evaluating pathologies associated with autonomic nervous system control, warranting further exploration and novel approaches.

Survey of Practice Patterns in the Use of Superior Laryngeal Nerve Blocks.

Superior laryngeal nerve (SLN) injection is performed for a variety of upper aerodigestive tract-related indications. Existing literature examines the efficacy of SLN injection for specific indications. However, there is a paucity of insight into overall practice patterns and a lack of standardization, particularly with regards to medication and dosing, treatment time frame, and circumstances. The goal of this study is to elucidate the practice patterns of SLN injection and allow for broader understanding of its utilization. This is a descriptive study of results from an electronic survey disseminated via email to US-based and international otolaryngologists and laryngologists. 80 responses were collected. 53.8% responders endorsed utilizing SLN injection in their practice, including 39/43 laryngologists (90.7%). Responders perform SLN injection for an array of indications, using a variety of anesthetic and steroid combinations and dosages. The most used steroid is triamcinolone (81.4%). The most used anesthetic is lidocaine (53.5%). 43% of respondents endorse willingness to perform bilateral injections simultaneously. Follow-up after initial injection is highly inconsistent, as are time intervals between injections and number of injections performed. With regards to side effects and complications discussed prior to the procedure, 95% counseled patients on pain/discomfort while roughly half of responders discussed bleeding/hematoma, aspiration risk, vasovagal response, and/or globus sensation, respectively. This is the first known study investigating the practice patterns of SLN injection. The substantial variability of responses reflects a lack of standardization of this procedure despite its widespread use. Further study is needed to optimize protocols. Levels 5 and 6 Laryngoscope, 2024.

Atrial rates during treated ventricular tachycardia in patients with implantable cardioverter defibrillators: clinical implications of a vagal sinus node response

Abstract Introduction Autonomic tone plays an important role in the genesis and sustenance of ventricular tachycardia (VT). Whilst sympathetic hyperactivity is an established driver of ventricular arrhythmias, sinus node response during VT varies broadly between patients, and can be paradoxical. Purpose We hypothesized that device-detected changes in sinus node rate could be an important surrogate of the autonomic response to VT, and may exert significant – and potentially modifiable – haemodynamic consequences independent of ventricular activity. Methods Device electrograms were analysed from consecutive patients with dual chamber implantable cardioverter defibrillators (ICDs) requiring anti-tachycardia pacing (ATP) or defibrillation for sustained monomorphic VT. Atrial rates were measured before VT onset (‘baseline’) and again at the point of detection by the device. Sinus node response was characterized as ‘stable’ (atrial rate remained within 10% of baseline), ‘sympathetic’ (atrial rate increased >10%) or ‘vagal’ (atrial rate decreased >10%). Patients who did not maintain ventriculoatrial dissociation or who presented in atrial tachyarrhythmia were excluded. Symptoms and electrical response to ICD therapies were recorded. Results 172 treated episodes of VT were included from 97 patients (median age: 69 years, 65% male, 31% ischaemic cardiomyopathy, median ventricular rate: 205bpm, median ejection fraction: 30%). Sinus node response was stable in 55%, sympathetic in 24% and vagal in 21%. A vagal response was associated with ATP-refractory VT (OR: 2.2 (1.1-4.8) p=0.03) and, when adjusting for ventricular rate, was independently associated with symptoms of presyncope or syncope (adjusted OR: 6 (2.7-13.7), p<0.0001). Conclusions This preliminary analysis suggests that a vagal sinus node response during VT is associated with adverse outcomes in ICD patients. Vagolytic therapy has recently been demonstrated to improve haemodynamic tolerance during VT ablation; whether supportive atrial pacing during VT could mitigate symptoms and potentiate arrhythmia termination in ICD patients warrants further exploration. Figure 1: Change in sinus node rate during sustained monomorphic ventricular tachycardia in patients with dual chamber ICDs, stratified by the occurrence of presyncopal symptoms or syncopeFigure 1

Machine learning model using heart rate variability for the prediction of vasovagal syncope

Abstract Background and Aims: Vasovagal syncope (VVS) is a reversible condition that can cause serious events, such as cerebral hemorrhage due to head trauma. Its occurrence is difficult to predict; therefore, this study aimed to develop machine learning (ML) models using heart rate variability (HRV) to predict the occurrence of VVS. Methods and Results We investigated 80 patients with syncope who underwent Holter monitoring during the head-up tilt test. Twenty-six ML models for the prediction of VVS using HRV parameters were examined. We randomly split the subjects into training and testing sets at a 7:3 ratio (training set: 46 positive and 9 negative subjects; testing set: 21 positive and 4 negative subjects). The XGB classifier achieved the highest performance compared with other algorithms (accuracy, 0.72; area under the curve, 0.801; sensitivity, 0.857; specificity, 0.621). When examining the time taken to predict syncope occurrence using the developed prediction model, it was found that the model could forecast approximately 3 min (equivalent to 193.2 beats) prior to the onset of symptoms. Conclusion The ML model utilizing HRV parameters was proficient in preemptively predicting VVS incidents. In practical applications, this approach can effectively enhance VVS prediction by leveraging the HRV, thereby aiding in the prevention of unforeseen accidents.

Selective use of implatable loop recorders improves diagnostic potential for unexplained syncope

Abstract Background Syncope remains a common medical problem with significant socio-economic consequences. Recently, the role of dedicated Syncope Units (SU) and implantable loop recorders (ILR) has emerged, in the investigation of unexplained syncope. Purpose To investigate the possibilities for a more rational and targeted use of various diagnostic tools. Methods In this retrospective study, 196 patients with Unexplained Syncope admitted in a single SU, between March 2019 and February 2023 were included. Various diagnostic tools were utilised during the investigational process, according to clinical judgement. Patients were retrospectively allocated into Group A including those who, among other tests, underwent ILR insertion and Group B including patients investigated without ILR implantation. Data were also compared with Group C, including patients assessed prior to SU establishment. Results There was no difference between Group A (n=133) and Group B (n=63) in the diagnostic yield (74% vs. 76%, p=0.22). There was significant difference between Group A and B regarding age (67.3 ± 16.9 years vs. 48.3 ± 19.1 years, p<0.001) and regarding cause of syncope (cardiogenic in 69% of group A and reflex syncope in 77% of group B, p<0.001). The diagnosis was based on electrocardiography (ECG) in 55% of group A and in 19% of group B (p<0.001). Time to diagnosis was 4.2 ± 2.7 months in patients with ILR implantation and 7.5 ± 5.6 months in Group B, p<0.001. In Group C, the diagnostic yield was 57.9% and the ECG-based diagnostic yield was 18.3%. Conclusions A selective use of ILR according to the clinical and electrocardiographic characteristics represents an acceptable diagnostic pathway that increases the effectiveness of the structured SU-approach by further preserving financial resources

Importance of the left superior ganglionated plexus ablation for the denervation of atrioventricular node: the impact of patient gender and bradycardia phenotype

Abstract Background Cardioneuroablation has been proposed as a new therapeutic option in selected patients with symptomatic functional bradyarrhythmia including recurrent neurally-mediated syncope. The contribution of individual ganglionated plexi to cardiac autonomic regulations is not fully established. Purpose It appears that ablation of the left superior ganglionated plexus (LSGP) is inoperable for the denervation of the sinoatrial node (SAN) and infrequently required for the denervation of the atrioventricular node (AVN). We explored the conditions that are associated with the need for LSGP ablation. Methods The study included 177 otherwise healthy patients aged 41 ± 12 years; 55% of males; 36% with predominant AVN disorder (29% in males, 44% in females, P <0.05) who underwent their first cardioneuroablation for symptomatic bradyarrhythmias at our centre between 2019 – 2024. Anatomically-navigated radiofrequency ablation with a bi-atrial approach was performed. In all patients, we ablated first the superior paraseptal (former right superior) ganglionated plexus (SPSGP) and inferior paraseptal (former posteromedial left) ganglionated plexus (IPSGP). Extracardiac vagus nerve stimulation (ECVS) via right and left jugular vein in general anaesthesia was used to assess the residual parasympathetic modulation of the AVN. If AVN was not completely denervated after the SPSGP and IPSGP ablation, the LSGP was targeted. Results Ablation of SPSGP and IPSGP resulted in SAN and AVN denervation in the majority of patients. LSGP ablation was required in 39 / 177 (22%) patients; in 31% of females vs. 14% of males (P <0.01); in 41% vs. 12% (P <0.0001) of patients with predominant AVN vs. SAN disorder, respectively. The corresponding decomposition is provided in the Table. In multivariate analysis, both female gender (P <0.05) and AVN disorder (P <0.001) were independently associated with the need for LSGP ablation. When the population was dichotomized into early (September 2019 – December 2021) and recent period (January 2022 – February 2024), the need for LSGP ablation had a downward trend (28% vs. 16%, P <0.05). Conclusions LSGP ablation to finalize the AVN denervation is required in a minority of patients. This need is independently associated with the female gender and predominant AVN disorder. The ECVS guidance in the ablation of SPSGP and IPSGP contributes to the decreasing trend of LSGP ablation, i.e. minimizing the final lesion set.Rate of LSGP ablation

Cardioneuroablation for the treatment of carotid sinus syndrome

Abstract Introduction Carotid sinus syndrome (CSS), characterized by exaggerated vagal responses leading to asystolic pauses with carotid sinus massage (CSM), often necessitates pacemaker implantation. This study investigates cardioneuroablation (CNA) as an alternative management strategy for CSS. Methods Prospective study of consecutive patients referred for CNA. All patients underwent CSM, atropine test, 24-hour Holter monitoring and SF-36 quality of life questionary before the procedure and at 6 months. The objective of the study was to assess syncope free survival, grade of cardioinhibition with CSM and heart rate variation (HRV) and quality of life after the procedure. Results A total of 13 patients (84.6% male, mean age 63.8 ± 12.3 years) were included. After a median follow-up of 11.2 (10.6-16.3) months, none of the patients experienced syncope (0%) and none of the patients required pacemaker implantation. After the procedure all the patients had a negative CSM and only one patient (7.7%) had a positive CSM at 6 months (Figure 1). There was an improvement in the energy and health change items in the SF-36 quality of life questionary (Figure 2). There was a reduction in HR increase in the atropine test at 6 months (pre-CNA: 66% (52-84) vs. post-CNA 27.4% (21.9-90.9); p=0.027) and in most of the 24-hour Holter monitoring HRV parameters. Conclusions Cardioneuroablation emerges as a promising and effective alternative to pacemaker implantation in managing cardioinhibitory CSS. Further research is warranted to solidify these findings and explore the long-term effects of CNA in this scenario.Figure 1Figure 2

Post-Exercise Syncope in a Previously Healthy 67-Year-Old Man: The Bezold–Jarisch Reflex and the Role of Autonomic Nervous System Dysfunction

A 67-year-old man started treatment due to frequent asymptomatic premature ventricular complexes (PVCs) accidentally being registered during a preventive examination by a specialist, because of which he was referred to cardiologist. During the initial 24-hour (h) ECG monitoring, 4.5% PVCs and one episode of asymptomatic non-sustained ventricular tachycardia (NSVT) with three PVCs in row, at a frequency of 150 beats per minute (bpm), were detected. After the introduction of beta blockers into therapy, a lower number of PVCs, without NSVT, were recorded in the control 24 h Holter ECG, while transthoracic echocardiography (TTE) showed normal left ventricular (LV) systolic function without cardiomyopathy. So, an exercise test was indicated, and it was interrupted in the third minute at 120 beats per minute (bpm) due to fatigue and pain in the hips, without malignant arrhythmias, angina or dyspneic complaints. During the rest period, a significant inferolateral depression of the ST junction was observed, which recovered in the ninth minute. Immediately after the ECG monitoring stopped, the patient lost consciousness; his pulse was not palpable, but breathing was audible, so cardiac massage was started. After he had regained consciousness, the ECG showed alternating sinus and junctional rhythm with the lowest frequency of 33 bpm, which was accompanied by marked hypotension (80/50 mmHg). The patient was immediately hospitalized; coronary angiography and repeated TTE were completely normal, while continuous ECG monitoring did not confirm malignant rhythm disorders or asystole. It was concluded that it was vasovagal syncope (VVS), most likely caused by the Bezold–Jarisch reflex (BJR).

Factors affecting the syncopal episodes in pediatric vasovagal syncope.

To investigate factors that influence the syncopal episodes in pediatric vasovagal syncope (VVS). A retrospective analysis was performed on the clinical data of 2908 children who were diagnosed with VVS for the first time between January 2001 and February 2023. The study examined the linear relationships among age, sex, height, weight, heart rate (HR), blood pressure, hemodynamic type, and head-up tilt test (HUTT) mode in relation to the onset of syncope. (1) Comparative analysis of intergroup differences revealed statistically significant variations in sex, age, height, weight, HR, systolic blood pressure, hemodynamic classification, and HUTT mode among syncopal episodes groups (P < 0.05); (2) Univariate analysis identified age, female, height, weight, VVS-cardioinhibited type (VVS-CI), VVS-mixed type (VVS-M) as potential risk factors for syncope episodes. Conversely, HR and sublingual nitroglycerin HUTT (SNHUT) emerged as potential protective factors against syncope episodes. (3) Multivariate analysis indicated that the frequency of syncope episodes increased by 0.27/0.02 for each unit increase in age/weight. When females compared to males and VVS-CI and VVS-M compared to VVS-vasoinhibited type (VVS-VI), the frequency of syncope episodes increased by 1.36, 0.53, and 0.66 respectively. Furthermore, SNHUT was associated with a reduction in the number of syncope episodes by 0.34 relative to basic HUTT. Female, age, weight, VVS-CI, and VVS-M were identified as independent risk factors for syncopal episodes, while SNHUT was recognized as an independent protective factor against syncopal episodes.

A higher peak heart rate during head-up tilt test predicts the therapeutic efficacy of metoprolol in vasovagal syncope

BackgroundAlthough beta blockers, such as metoprolol, have been widely used in the management of vasovagal syncope (VVS), their efficacy remains debated, with larger studies showing limited benefit. Identifying patient-specific characteristics that predict a positive response to metoprolol could optimize its use. This study aims to investigate the key factors that may determine which VVS patients are suitable candidates for metoprolol treatment.MethodsThis retrospective study was conducted at a single center. Patients diagnosed with VVS and treated with metoprolol for a minimum of three months were included. A 50% reduction in syncope symptom score (SS) after three months of metoprolol treatment was used to define metoprolol responders, while those who did not achieve this reduction were classified as non-responders. After a three-month follow-up, patients were divided into two groups: responders and non-responders. Baseline data—including age, gender, comorbidities, laboratory tests, and the type of VVS—were analyzed for each patient. Changes in heart rate (HR) and blood pressure during the head-up tilt test (HUTT) were also evaluated between the two groups. Logistic regression analysis was performed to identify potential predictors of metoprolol response, and receiver operating characteristic (ROC) curve analysis was used to assess the value of these predictors in selecting potential responders.ResultsA total of 168 VVS patients were enrolled between January 2016 and December 2020. Of these, 100 patients responded positively to metoprolol, while 68 did not. No significant differences in baseline characteristics or HUTT results were observed between the two groups (p > 0.05). However, responders exhibited a significantly higher peak HR compared to non-responders during the HUTT (120.13 ± 19.33 vs. 106.60 ± 22.32, p < 0.001). The increase in HR was also more pronounced in responders (0.60 ± 0.23 vs. 0.41 ± 0.25, p < 0.001). Additionally, HR variability was significantly greater in responders than in non-responders (16.18 ± 5.51 vs. 12.61 ± 5.50, p < 0.001).ConclusionHigher peak HR, larger increases in HR, and greater HR variability during the HUTT may serve as reliable predictors of a positive response to metoprolol in patients with VVS.

Mesenteric blood flow and muscle sympathetic nerve activity during vasovagal syncope.

Vasovagal syncope is thought to be mediated by a progressive fall in cardiac output secondary to venous pooling of blood in the splanchnic circulation. How and when this occurs before syncope has not been determined. A total of 20 patients who became hypotensive during head-up tilt (age 40.9 ± 3.4 years; 10 females) were divided into two groups-the glyceryl trinitrate (GTN) group (n = 12) and the vasovagal syncope (VVS) group (n = 8) - on the basis of whether or not nitroglycerine provocation was required. They were compared with a control group (age 38.6 ± 3.3; 8 females; n = 13). Hemodynamics, including superior mesenteric artery blood flow (SMABF) and muscle sympathetic nerve activity (MSNA) were recorded continuously during early tilt, presyncope and recovery. We used pixel-weighting to calculate average velocity from the pulsed Doppler velocity envelope. During baseline and early tilt, resistance to mesenteric blood flow was lower in the VVS group: 0.30 ± 0.02 to 0.30 ± 0.02mmHg/ml/min versus controls 0.30 ± 0.03 to 0.38 ± 0.04mmHg/ml/min (p = 0.05). During presyncope, as blood pressure and stroke volume gradually fell, SMABF was higher in the VVS group, falling from 370 ± 46 to 248 ± 35ml/min, versus controls, falling from 342 ± 51 to 233 ± 19 (p = 0.03). At this time, MSNA was lower in the VVS group than controls: 39 ± 4 to 34 ± 3 bursts/min versus 45 ± 2 to 48 ± 3 (p = 0.001). During presyncope, increased splanchnic blood flow may pool more blood in capacitance vessels resulting in decreased venous return and cardiac output. This may be secondary to decreased vasoconstrictor sympathetic activity.

Resting cortisol concentrations in dogs presenting to a university teaching hospital with collapse.

The relationship between collapse and a diagnosis of hypoadrenocorticism is not well understood in dogs. To assess the prevalence of episodes of collapse in dogs screened for hypoadrenocorticism, and to assess the prevalence of confirmed hypoadrenocorticism in dogs presenting with reported collapse. Seventy-three client-owned dogs with resting cortisol concentrations were measured and presented to a University teaching hospital for collapse. Retrospective review of medical records of dogs at a single center. The prevalence of episodes of collapse in dogs that had a resting cortisol measurement was 73/856 (8.5%; 95% confidence interval [95% CI], 6.7%-10.6%). Resting cortisol concentration was <2 μg/dL (<55 nmol/L) in 19 dogs. Cortisol concentration after ACTH stimulation was <2 μg/dL (<55 nmol/L) in 1 of the 73 dogs in this cohort, consistent with a diagnosis of hypoadrenocorticism, giving a prevalence estimate of hypoadrenocorticism of 1.3% (95% CI, 0.15%-6.2%). In 8 dogs with an initial resting cortisol concentration <2 μg/dL (<55 nmol/L), hypoadrenocorticism was excluded based on a repeat resting cortisol concentration >2 μg/dL (>55 nmol/L). The most common diagnosis was vasovagal syncope (10/73), followed by sick sinus syndrome and third-degree atrioventricular block (2/73). The final diagnosis was unknown in 24/73 dogs. Hypoadrenocorticism was the final diagnosis in 1 of 73 dogs presented to a teaching hospital either in a collapsed state or with a previous history of episodes of collapse. No dog presenting as cardiovascularly stable for intermittent collapse was found to have hypoadrenocorticism.

Endocardial ablation of ganglionated plexus for the treatment of carotid sinus syndrome.

Carotid sinus syndrome (CSS), characterized by exaggerated vagal responses leading to asystolic pauses with carotid sinus massage (CSM), often necessitates pacemaker implantation. This study investigates cardioneuroablation (CNA) as an alternative strategy for CSS. Prospective study of consecutive patients referred for CNA due to CSS. All patients underwent CSM, atropine test and 24-h Holter monitoring before the procedure and at 6 months. The primary objective was the absence of any cardioinhibitory response to CSM following CNA. Secondary objectives included the combined endpoint of syncope and presyncope-free survival, pacemaker-free survival, differences in heart rate variation (HRV), as well as differences in the pre- and postprocedure atropine tests and in the SF-36 quality-of-life questionnaire. A total of 13 consecutive patients (84.6% male, mean age 63.8 ± 12.3 years) were included. CSM revealed a symptomatic asystolic pause in all patients before CNA (7.3 [5.6-10.5] s). After the procedure, all the patients had a negative CSM, and only one patient (7.7%) had a positive CSM at 6 months. After a median follow-up of 11.2 (10.6-16.3) months, syncope or presyncope-free survival was 84.6%, and none required pacemaker implantation. There was an improvement in the energy and health change items in the SF-36 questionnaire. There was a reduction in HR increase in the atropine test at 6 months (pre-CNA: 66% [52-84] vs. post-CNA 26.0% (19.8-29.3]; p = .008) and in HRV parameters. In this proof-of-efficacy study, performed in patients affected by asystolic CSS, CNA was effective in reducing the rate of cardioinhibitory responses, suggesting a potential efficacy in also reducing syncopal recurrences. Controlled trials are warranted to corroborate clinical findings.

The Effect of Gum Chewing on Gastrointestinal System Functions in Patients Undergoing Colorectal Surgery: A Systematic Review

In the postoperative period, gas and secretions in the stomach and small and large intestines due to delayed motility of the gastrointestinal system cause abdominal bloating, nausea, vomiting and pain, and this situation negatively affects the comfort level of patients. Chewing gum is among the methods used to prevent ileus after surgery. Chewing gum activates the cephalic vagal reflex and stimulates bowel function in the postoperative period. In this article, the effect of chewing gum in preventing ileus after colorectal surgery and the factors affecting the success rate are reviewed in the light of current literature.

Fluoroscopy-free cardioneuroablation for functional bradycardia: a single-center experience.

Cardioneuroablation (CNA) is an emerging treatment for cardioinhibitory syncope and functional AV block. This study aimed to evaluate the safety and efficacy of a fluoroless CNA approach using three-dimensional mapping and extracardiac vagal stimulation (ECVS). This prospective observational study included 22 patients (mean age 21years) with clinically significant functional bradycardia who underwent fluoroless CNA. Procedural success was defined as elimination or significant attenuation of the vagal response to ECVS. CNA was successfully performed in all patients with a mean procedure time of 251min. Fluoroscopy was avoided in 91% of cases. At a mean follow-up of 11.4months, 77% of patients remained symptom-free. Among pacemaker patients, 90% did not require further pacing, and 6/10 (60%) have had their pacemakers turned off. No complications were seen during the procedure. Fluoroscopy-free CNA is a safe and effective treatment for functional bradycardia, offering high procedural success rates and favorable symptom-free outcomes while minimizing radiation exposure.

Comparison of the effectiveness of 0.5% and 0.25% proparacaine hydrochloride eye drops as topical anesthetics in routine ocular investigations and procedures.

To compare the effectiveness of 0.5% and 0.25% proparacaine eye drops in providing topical anesthesia for routine ocular procedures. 137 patients (274 eyes) were included in this study. They were categorized into two groups. Group A patients received 0.5% and Group B received 0.25% proparacaine drops. A single surgeon performed all the procedures. Intraprocedural and postprocedural pain scores, surgeon comfort, supplemental anesthesia, and vital parameters, were noted. The mean age of the participants was 69.42 years (±12.05). An equal number of procedures were performed (n = 30) for applanation tonometry, lacrimal sac syringing, and A-scan biometry. The other procedures performed were removal of the conjunctiva (n = 5) and corneal foreign bodies (n = 16 per group), corneal scraping (n = 8 per group), and corneal suture removal (n = 18 per group).The mean visual analog pain score during the procedure was 6.9663 in Group A and 8.0803 in Group B (P = 0.66). The mean postprocedural pain score was not significant (P = 0.21). None of the patients required any additional anesthesia during or after the procedure. The average surgeon's experience was 0.152±0.507 in Group A and 0.111±0.402 in Group B (P = 0.07).In Group A, 133 of 137 patients (97.08%), and in Group B, 132 out of 137 patients (96.35%) preferred to use the same anesthetic for future procedures. None of the patients experienced a vasovagal attack or any change in vital parameters. The present study aimed to establish equivalence between two concentrations of proparacaine hydrochloride in which false positive and false negative errors were expected. This is the inherent challenge in the equivalence and inferiority trials. To mitigate these risks, the present study was carefully designed with specific statistical methods, sample size calculation, and rigorous methodology. Nevertheless, it is crucial to recognize that the risk of false positive errors remains, and the results should be interpreted with this in mind. These findings indicated that 0.25% proparacaine is a viable alternative to the standard 0.5% concentration in routine ophthalmic procedures, with the potential for improved patient comfort.

Failure of pacemaker therapy in a pediatric patient with neurally mediated complete heart block and syncope: A case report.

Neurally mediated syncope (NMS) is a well-known condition that can be subdivided into three subgroups: vasopressor type, cardioinhibitory type, and mixed type. While different degrees of sinus bradycardia occur at the time of syncope in all types, complete heart block is a rare event that can lead to pulselessness during syncope. We present a case of a 14-year-old girl with documented NMS before and after temporary pacemaker implantation, who had complete heart block during syncope. The patient's temporary pacemaker placement was ineffective in preventing syncope during a repeat head-up tilt test, indicating that permanent pacing may not be effective in this patient. Midodrine, an alpha-adrenergic agonist, was started, and the patient experienced complete control of syncope episodes without recurrence during a 2-month follow-up.

TCT-97 A Meta-Analysis of Cardioneuroablation Efficacy in Achieving Syncope Freedom in Neurocardiogenic Syncope

TCT-97 A Meta-Analysis of Cardioneuroablation Efficacy in Achieving Syncope Freedom in Neurocardiogenic Syncope