Vasovagal Research Articles

Catheter Ablation for Vasovagal Syncope: The Therapeutic Potential of Gateway Plexi

Vasovagal syncope (VVS) is the most common cause of syncope, and significantly impacts quality of life despite its benign nature. For some patients, conventional management strategies such as lifestyle changes, pharmacotherapy and pacemaker implantation, fail to prevent recurrence. Cardioneuroablation (CNA), a novel intervention targeting the cardiac autonomic nervous system’s ganglionated plexi, has shown promise in addressing refractory VVS. This review examines the therapeutic potential of CNA, exploring the anatomy and physiology of the cardiac autonomic nervous system, the role of ganglionated plexi in cardiac regulation and the rationale behind their selection as ablation targets. The review also discusses diverse strategies for ganglionated plexi identification and ablation. The gateway ganglionated plexi hypothesis is used to explain the success of CNA across varied procedural methods, despite the absence of a standardized technique. These gateway ganglionated plexi, located near the sinoatrial and atrioventricular nodes, potentially serve as central nodes influencing heart rhythm and rate, thus explaining the high success rates in VVS treatment using different approaches.

Cardioneuroablation for reflex syncope or functional bradyarrhytmias: new insight from a single center experience

BackgroundCardioneuroablation (CNA) is a new approach to treat reflex syncope and functional bradyarrhytmias caused by autonomic imbalance. We report our experience using CNA.MethodFrom September 2022 to July 2023, we took care of 21 patients (mean age 42 ± 21 years; 62% male) affected by reflex syncope or functional bradyarrhythmias. All patients underwent CNA under conscious sedation targeting the superior and/or inferior paraseptal ganglionated plexus (GPs).ResultsNine patients were affected by vasovagal syncope (VVS) and twelve by functional bradyarrhythmias. In 3 cases (14%) the ablation was performed only on the GPs of the right atrium, while in the remaining 86% of cases we performed biatrial lesions. As regards the acute results, we highlighted an increase in sinus heart rate (12 ± 15 bpm, p = 0.001), a shortening of the PQ interval (−18 ± 18 msec, p < 0.001), a reduction of the correct sinus node recovery times (cSNRT) (−142 ± 204 msec, p = 0.114), a shortening of the AH interval (−31 ± 26 msec, p = 0.008), a reduction of the effective refractory period of the atrio-ventricular node (−156; interquartile range from −30 to −160 msec, p = 0.042) and an increase in the Wencheback point (27 ± 20 bpm, p < 0.001). At follow-up, a single patient, due to persistent symptoms and bradyarrhythmic disorder, underwent permanent pacemaker implantation; no other patient had recurrence of syncope, and all remained persistently asymptomatic.ConclusionOur results confirm the efficacy and safety of CNA for the treatment of VVS and functional bradyarrhythmias, although further studies are needed to support these findings.

Mechanisms of exercise-related neurocardiogenic syncope and the relationship between resting and dynamic cardiac testing.

Syncope is common among pediatric patients and is rarely pathologic. The mechanisms for symptoms during exercise are less well understood than the resting mechanisms. Additionally, inert gas rebreathing analysis, a non-invasive examination of haemodynamics including cardiac output, has not previously been studied in youth with neurocardiogenic syncope. This was a retrospective (2017-2023), single-center cohort study in pediatric patients ≤ 21 years with prior peri-exertional syncope evaluated with echocardiography and cardiopulmonary exercise testing with inert gas rebreathing analysis performed on the same day. Patients with and without symptoms during or immediately following exercise were noted. Of the 101 patients (15.2 ± 2.3 years; 31% male), there were 22 patients with symptoms during exercise testing or recovery. Resting echocardiography stroke volume correlated with resting (r = 0.53, p < 0.0001) and peak stroke volume (r = 0.32, p = 0.009) by inert gas rebreathing and with peak oxygen pulse (r = 0.61, p < 0.0001). Patients with syncopal symptoms peri-exercise had lower left ventricular end-diastolic volume (Z-score -1.2 ± 1.3 vs. -0.36 ± 1.3, p = 0.01) and end-systolic volume (Z-score -1.0 ± 1.4 vs. -0.1 ± 1.1, p = 0.001) by echocardiography, lower percent predicted peak oxygen pulse during exercise (95.5 ± 14.0 vs. 104.6 ± 18.5%, p = 0.04), and slower post-exercise heart rate recovery (31.0 ± 12.7 vs. 37.8 ± 13.2 bpm, p = 0.03). Among youth with a history of peri-exertional syncope, those who become syncopal with exercise testing have lower left ventricular volumes at rest, decreased peak oxygen pulse, and slower heart rate recovery after exercise than those who remain asymptomatic. Peak oxygen pulse and resting stroke volume on inert gas rebreathing are associated with stroke volume on echocardiogram.

Case Report: Painful left bundle branch block syndrome complicated with vasovagal syncope

Case Report: Painful left bundle branch block syndrome complicated with vasovagal syncope

Acute Effects of Slow-Paced Breathing on Measures of HRV in Hospitalized Patients With Bilateral COVID-19 Pneumonia: A Secondary Analysis of a Randomized Clinical Trial.

Slow-paced breathing (SPB) with prolonged exhalation is assumed to stimulate vagal reflexes, which is represented by increased heart rate variability (HRV) values. However, most trials were conducted in healthy participants. We sought to evaluate the feasibility of SPB in hospitalized patients with confirmed bilateral COVID-19 pneumonia with major respiratory impairment and to investigate if SPB shows acute increasing effects on HRV measures in these severely ill patients with distinctly reduced vagal tone. This single-center randomized controlled clinical trial enrolled 23 patients in the intervention (4-second inhalation, 6-second exhalation for 20 minutes 3× daily) and 23 patients in the control group (IG/CG). The effects of SPB on HRV were calculated using post-hoc likelihood ratio tests. Baseline HRV measures between the groups over time were compared using multilevel mixed-effect linear regression models with random slope including the covariates relevant comorbidities, COVID-19 medication, and age. HRV values at baseline were significantly decreased in all patients. During SPB, HRV parameters increased significantly (ln(SDNN), ln(LF), ln(TP); all p < .001). Higher breathing rate at baseline correlated with lower LF during SPB (p < .045). IL-6 morning levels were associated with lower HRV measures (p < .001). Resting HRV measures as well as subjective health increased over hospitalization time with no differences between IG and CG (comparing random slope with random slope interaction models: all LR χ2(5) < 4.5; p > .48). SPB is feasible and safe in patients with bilateral COVID-19 pneumonia and appears to be an effective self-performed intervention to acutely increase HRV measures. This observation was independent of comorbidities and comedication. Further trials should corroborate these findings and extend it to other severely ill populations. German Clinical Trials Register under ID DRKS00023971 (https://drks.de/search/en/trial/DRKS00023971), with a Universal Trial Number (UTN) U1111-1263-8658.

Syncope: Advances in Diagnosis and Treatment 2024.

In light of many recent advances in the field of vasovagal syncope, a selective review has been undertaken of these developments. Recent publications on the following topics were reviewed; understanding of vasovagal syncope pathophysiology, tilt-testing methodology and interpretation, drug, ablation and pacemaker therapy. The vasovagal syncope field is very active in researching its pathophysiology, using it to gain better understanding of the process and applying this knowledge to therapy.

Left Ventricular Hypertrabeculation (LVHT) in Athletes: A Negligible Finding?

Left ventricular hypertrabeculation (LVHT) used to be a rare phenotypic trait. With advances in diagnostic imaging techniques, LVHT is being recognised in an increasing number of people. The scientific data show the possibility of the overdiagnosis of this cardiomyopathy in a population of people who have very high levels of physical activity. We describe the case of a young athlete with no medical history, who presented with syncope during a marathon running race. Initial evaluation showed elevated troponin I; transthoracic echocardiography showed a trabeculated ventricle and subsequent cardiac magnetic resonance (CMR) revealed left ventricular hypertrabeculation (LVHT). During subsequent evaluation by tilt table testing, vasovagal syncope was identified as the likely aetiology of the syncope. The patient was advised to cease sports and stimulants like caffeine use. At the 29-month follow-up, CMR showed the normalisation of the non-compacted to compacted myocardial ratio and an improvement in left ventricular function, with no further syncopal episodes reported. This is an example of the physiological hypertrabeculation of the LV apex in a recreational endurance athlete, with the normalisation of the non-compacted to compacted myocardial layer ratio after detraining. Physiological hypertrabeculation, a benign component of exercise-induced cardiac remodelling, must be differentiated from non-compaction cardiomyopathy and other pathologies causing syncope. This case underscores the importance of distinguishing physiological hypertrabeculation from pathological LVHT in athletes, highlighting that exercise-induced cardiac remodelling can normalise with detraining.

Appetitive traits in adolescents with vasovagal syncope

Aim: This study was designed to explore the peculiarities of eating behavior in adolescents with vasovagal syncope and to identify a possible correlation between clinical data and some appetitive traits that could potentially be associated with the development of syncope. Methods: In total, 69 adolescents with vasovagal syncope and 60 healthy participants underwent clinical examination, vitamin panel (pyridoxine, folate, cobalamin, vitamin D), homocysteine testing, and simultaneously completed the Ukrainian validated version of the Adult Eating Behavior Questionnaire. The feasibility, reliability, and validity of the scales were assessed in this version. The associations of Questionnaire scales with syncope characteristics were analyzed. Results: Our study has shown good psychometric properties of the Ukrainian version of the Adult Eating Behavior Questionnaire for assessing eating behavior in adolescents with vasovagal syncope. Our study revealed lower scores on enjoyment of food and greater scores on satiety responsiveness trait in patients with vasovagal syncope. Lower food responsiveness was associated with a higher number of syncope events, and higher food fussiness predicted a longer duration of syncope history. Reduced food responsiveness and fussy eating in adolescents with vasovagal syncope have also been linked to lower levels of neurotropic vitamins and hyperhomocysteinemia. Conclusions: Our analysis suggests that vitamin deficiency and autonomic dysfunction in adolescents with VVS could be linked to eating disturbances. One potential approach for prevention and treatment is to provide nutrition education for syncope patients. Clinicians should be aware of the impact of eating behavior, which could help in preventing future syncope attacks and disease progression.

Malignant vasovagal syncope in children.

Malignant vasovagal syncope (VVS) is a unique form of cardioinhibitory VVS, characterized by prolonged asystole. To deepen the understanding of this distinct type of VVS in children, this article reviews advancements in the potential pathogenesis, diagnostic approaches, clinical significance, and treatment controversies of malignant VVS in pediatric patients. This article was developed by reviewing the literature and studies in databases including PubMed and Chinese Journal Full-text Database up to September 2024. Search terms included "malignant vasovagal syncope" AND "children" or "vasovagal syncope" AND "asystole" AND "children". To date, studies focused on malignant VVS in children remain limited. Theoretically, children with malignant VVS are at risk of physical or mental impairment due to this cardiac asystole, though no definite conclusions have been reached. The mechanism underlying the significant cardiac inhibition in malignant VVS remains unclear, and the treatment strategy of malignant VVS is debatable. The understanding of children with malignant VVSis insufficient. Further research is required to evaluate the clinical features and the pathogenesis of pediatric VVS with cardiac asystole and to establish effective management strategies for malignant VVS. Video Abstract.

Differential and synergistic effects of right and left atrial ganglionated plexi ablation in patients undergoing cardioneuroablation: results from the ELEGANCE multicenter study.

Cardioneuroablation (CNA) treats reflex syncope by ablating ganglionated plexi (GPs) either confined to the right (RA) or left atrium (LA), or accessible from both. We assessed whether GP ablation in one atrium affects parasympathetic modulation in the other and how ablation sequence (RA then LA, or vice-versa) impacts efficacy. Two propensity-matched groups of patients with reflex syncope or functional bradycardia were analyzed. Group 1 received CNA in the RA first, followed by LA. Group 2 in the reverse order. Thirty-four patients were enrolled. In group 1, RA ablation prompted a heart rate (HR) increase (49.8 ± 10.6 vs. 61.2 ± 13.8bpm; p < 0.01) that was enhanced after LA ablation (60.3 ± 14.5 vs. 64.5 ± 14.4bpm; p = 0.02). RA ablation did not reduce PR interval in any patient or modify the Wenckebach point (WP) (596 ± 269 vs. 609 ± 319ms; p = 0.68), while additional LA ablation reduced PR interval in 3 patients and mean WP (611 ± 317 vs. 482 ± 191ms; p = 0.03). In group 2, LA ablation increased HR (56.7 ± 6.6 vs. 76.4 ± 13.8bpm; p < 0.01), with an additional effect of RA ablation (76.0 ± 16.5 vs. 85.4 ± 15.9bpm; p < 0.01). LA ablation decreased PR interval in 3 patients and mean WP (512 ± 182 vs .399 ± 85ms; p = 0.01). Further RA ablation did not decrease PR or WP. CNA success was 82% in group 1 and 100% in group 2 (p = 0.552). After 24.5 ± 6.1months, 2 patients in group 1 vs. no patients in group 2 experienced symptom recurrence. Bi-atrial CNA provides incremental benefits after both RA and LA ablation. Starting ablation in the LA provides the most significant effect on vagal modulation.

Inadvertent neuromodulation during pulmonary vein isolation for atrial fibrillation – immediate and short-term effects of radiofrequency and cryogenic energy

Inadvertent vagal denervation has been reported as an adjunctive effect during pulmonary vein isolation (PVI) for atrial fibrillation (AF). However, it is not known how frequent and durable this effect is during thermal ablation. Material and methods: This is a retrospective study of consecutive patients with AF and first PVI in sinus rhythm using radiofrequency or cryogenic energy. We studied the incidence of non-targeted and non-transient heart rate (HR) acceleration, induction and abolition of vagal reflex (VR), as well as the durability of the HR increase at the end of the first month. Results: PVI was carried out in 102 patients (cryo, n = 46). Overall, 60 patients (58.8%) had inadvertent neuromodulation, presented by VR induction and abolition (n = 18, 17.6%) and predominantly by HR increase (n = 50, 49%). In patients with vs those without HR acceleration the mean HR increase at the end of the procedure was 14.2 &amp;plusmn; 5.64 bpm vs. -2.63 &amp;plusmn; 5.43 bpm, and at the next day &amp;ndash; 10.6 &amp;plusmn; 7.53 bpm vs. 3.68 &amp;plusmn; 7.75 bpm (p &lt; 0.001 for all). The mean HR at 1 month was 74.2 &amp;plusmn; 9.91 bpm vs. 68.9 &amp;plusmn; 12 bpm (p = 0.048). Patients with a durable HR increase were younger (median age 61 vs. 65.5 years, p = 0.016) and less frequently had heart failure with reduced ejection fraction (1% vs. 6.9%, p = 0.031). Conclusion: Inadvertent neu-romodulation occurs in more than half of the patients with radiofrequency or cryo PVI for AF. It is mostly represented by a HR increase and persists for up to at least one month post-procedurally.

Vagal response during radiofrequency catheter ablation initiated from right superior pulmonary vein: Incidence, risk factors, and clinical outcomes.

The vagal response (VR) is unavoidable during pulmonary vein isolation (PVI) for atrial fibrillation (AF). In this study, we aimed to investigate the incidence, risk factors, and clinical outcomes of VR during PVI initiated from the right superior pulmonary vein (RSPV). Patients with AF were consecutively enrolled. PVI was initiated from the RSPV, followed by other PVs. The VR was defined as atrioventricular block (AVB), asystole, or a 50 % increase in the R-R interval. We enrolled 702 patients with AF (paroxysmal = 380, persistent = 322). Seventy-seven (11.0 %) patients developed 81 VR episodes, which were more common in paroxysmal than persistent AF (74 [19.5 %] vs. 3 [0.9 %], P < 0.001). VR manifestations in paroxysmal AF included sinus arrest in 51 (63.0 %) patients, sinus bradycardia in 26 (32.1 %), and AVB in one (1.2 %) patient. For persistent AF, VR manifested as AVB. Most VR episodes were observed in the left superior ganglionated plexi (n = 67, 82.7 %). Body mass index (BMI) ≥28.0 kg/m2 (odds ratio [OR] = 2.261, P = 0.005) and left ventricular ejection fraction (LVEF) ≥60.0 % (OR = 2.622, P = 0.018) were independent risk factors. Among patients with paroxysmal AF, seven (9.5 %) with VR and 34 (11.1 %) without VR had AF recurrence during a follow-up of 15.5 ± 4.6 months (P = 0.582). VR occurred more often in paroxysmal AF than in persistent AF during RSPV-initiated PVI, with specific manifestations. Increased BMI and LVEF were independent risk factors. Inadvertent VR does not predict better clinical outcome.

Yield of Tilt Table Test in Diagnosing Syncope in Patients With Suspected Neurally Mediated Syncope.

Syncope is a common medical condition. The reflex or neurally mediated syncope (NMS) is the most frequent type. The tilt table test (TTT) helps distinguish syncope from other common causes of complete loss of consciousness, such as epilepsy, define syncope subtypes and guide management. This study aimed to assess the TTT yield in patients with suspected NMS and to compare the nitroglycerin (NTG) and isoproterenol (Isuprel) provocative protocols. This study was a retrospective analysis of the data of 426 consecutive patients who underwent TTT at the Heart Center at King Faisal Specialist Hospital and Research Center (KFSH&RC), Riyadh, Saudi Arabia, between January 1, 2006, and March 31, 2017. The age at referral for TTT ranged from 7 to 84 years (mean 38.4 ± 15.75 years), and 212 (49.8%) were males. The main clinical manifestations were recurrent syncope in 259 patients (60.8%), a single syncopal episode in 60 (14.1%), and pre-syncope or dizzy spells without loss of consciousness in 171(25.1%). The test was positive in 295 patients (69.2%), with type 1 (mixed response) seen in 151 patients (51.19%), type 2a (cardioinhibitory without pause) in 16 (5.4%), type 2b (cardioinhibitory with pause) in 10 patients (3.39%), and type 3 (vasodepressor) in 118 patients (40%). A false positive test was seen in 11 patients (2.6%) and a false negative in 27 patients (6.3%). The overall test sensitivity was 91%, specificity was 89%, positive predictive value (PPV) was 96%, and negative predictive value (NPV) was 79%. The TTT is beneficial in diagnosing syncope in males and females and patients of young and old ages. A provocative test utilizing NTG provides a shorter, more straightforward test with the same diagnostic accuracy as the isoproterenol test. Lifestyle modification is effective and remains the primary intervention in managing patients with NMS.

The Impact of BMI on Heart Rate During Suspension Laryngoscopy Operation in Patients With Laryngeal Lesions: A Prospective Cohort Study.

Suspension laryngoscopy can trigger vagal reflexes, leading to a decrease in heart rate, a phenomenon that is more common in patients with a high body mass index (BMI). This study aims to systematically evaluate the effect of BMI on heart rate during suspension laryngoscopy (SL-HR) in patients with laryngeal lesions. We employed univariate generalized linear regression and stratified analyses to assess the relationship between BMI and changes in SLHR, adjusting for confounders such as age, gender, intubation type, and depth. A generalized additive model with spline smoothing was utilized to evaluate the BMI-HR relationship, with piecewise linear regression to identify specific cutoff points. We conducted a prospective study of 205 patients who underwent general anesthesia for suspension laryngoscopy. Multivariate linear regression analysis indicated that, after adjusting for covariates, each one-unit increase in BMI was associated with a decrease of 1.04 beats per minute in SL-HR (β=-1.04 [95% CI, -1.85 to -0.23]). Curve fitting revealed a gradual decline in SL-HR with increasing BMI, plateauing at around 60 beats per minute. The decrease in SL-HR became more pronounced as BMI approached 30kg/m², with further analysis revealing an inflection point at a BMI of 28.8kg/m², where each additional unit of BMI correlated with a 6.5 beats per minute decrease in heart rate (β =-6.5 [95% CI, -10.1 to -2.8], P <0.001). Patients with high BMI are more prone to vagal reflexes during suspension laryngoscopy, resulting in significant reductions in heart rate, especially when BMI exceeds 28.8kg/m². Therefore, close monitoring of heart rate changes is crucial in this patient demographic, along with considering prophylactic anticholinergic agents to mitigate vagal reflex effects.

Nomogram Based on HRV for Predicting the Therapeutic Effects of Orthostatic Training in Children with Vasovagal Syncope.

This study intended to find out whether the parameters of heart rate variability (HRV) can predict the treatment efficacy of orthostatic training among pediatric cases of vasovagal syncope (VVS). Patients with VVS who underwent orthostatic training were retrospectively enrolled. Lasso and logistic regression were used to sift through variables and build the model, which is visualized using a nomogram. The model's performance was evaluated through calibration plots, a receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) for both datasets. In total, 119 participants were included in the analysis, and 73 and 46 were assigned to the training and validation datasets, respectively. Five factors with nonzero coefficients were chosen based on lasso regression: age, the root means square of successive differences between normal sinus beats (rMSSD), standard deviation of the averages normal-to-normal intervals in all 5-min segments, minimum heart rate, and high frequency. Drawing from the logistic regression analysis results, the visual predictive model incorporated two variables, namely age and rMSSD. For the training dataset, the sensitivity was 0.686 and the specificity was 0.868 with an area under the curve (AUC) of 0.81 (95% CI, 0.71-0.91) for the ROC curve. For the validation dataset, the AUC of the ROC was 0.80 (95% CI, 0.66-0.93), while sensitivity and specificity were recorded at 0.625 and 0.909, respectively. In the calibration plots for both datasets, the predicted probabilities correlated well with the actual probabilities. According to the DCA, the visual predictive model gained a significant net benefit across a wide threshold range. Pediatric patients with VVS can benefit from orthostatic training using a visual predictive model comprising age and rMSSD.

Vestibular Syncope and Acute Peripheral Vestibular Deficit: A Case Report.

Vestibular syncope is a rare condition in which vertigo may cause syncopal attacks; however, the term has been associated with confusion because it has been ascribed to completely different vestibular and neurological conditions, from dizziness to Menière disease (MD), to the neurovegetative symptoms in benign paroxysmal positional vertigo (BPPV) and central vertebrobasilar hyperfusion. A 75-year-old woman with vasodepressive vasovagal syncope, confirmed by a tilt test with trinitrine administration, was referred for an audiological and vestibular assessment showing an acute unilateral peripheral vestibular deficit on the right side. The diagnosis is peripheral acute vestibular deficits. Interventions and outcomes are vestibular treatment and rehabilitation. The patient's vasovagal symptoms immediately improved and were completely resolved. Peripheral vestibular deficits might also trigger syncopal episodes and must be considered and studied by a complete audiological and vestibular evaluation. By restoring the peripheral vestibular function of the right labyrinth after vestibular treatment, a complete long-term resolution of multiple vasovagal syncopal episodes was observed together with normalization of the tilt test.

Continuous nursing care improving outcomes of patients after percutaneous coronary intervention.

Percutaneous coronary intervention (PCI) is an effective method for the treatment of coronary heart disease. Cardiac rehabilitation and continuous nursing management after discharge are the key to ensure the quality of treatment and the quality of life of patients. This study aimed to explore the significance of WeChat platform in continuous care after PCI. We collected the clinical data of 90 PCI patients in 2 centers from January 2020 to July 2023, and divided the patients into 2 groups: the continuous nursing care group based on the WeChat platform and the control group. Continuous nursing care was implemented immediately after discharge. After 1-year follow-up, we compared the outcomes of the 2 groups, including postoperative complications, lifestyle changes and psychological status. There were no heart-related postoperative complications in either group. The incidence of vagal reflex was significantly decreased in the continuous nursing group (P = .042). The improvement of life style, such as smoking cessation (P = .001) and alcohol withdrawal (P = .003), was significantly better than that of the control group. The continuous nursing group was better than the control group in improving psychological status based on the Hamilton's depression scale. Continuous nursing care based on WeChat platform could reduce the incidence of complications of patients after PCI, alleviate patients' depression, and improve patients' quality of life.

Predictive value of Tpeak-Tend interval of supine and orthostatic electrocardiogram in the diagnosis between psychogenic pseudosyncope and vasovagal syncope in children

Tpeak-Tend interval (Tp-Te) is an indicator of transmural dispersion of repolarization, which is often related to ventricular arrhythmias. The relationship between Tp-Te and vasovagal syncope (VVS) has been reported in previous studies, but very little is known about Tp-Te in differentiation between psychogenic pseudosyncope (PPS) and VVS in children. We aim to discuss the predictive value of Tp-Te of supine and orthostatic electrocardiogram (ECG) in the diagnosis between PPS and VVS in children. The 31 children with PPS and 40 children with VVS from July 2014 to November 2023 were enrolled as the study group. Meanwhile, 30 healthy children who underwent a physical examination in the same hospital were selected as the control group. Tp-Te and QT interval in 12-lead supine and orthostatic ECG were measured. (1) Supine ECG: ① The Tp-Te/QT in PPS group was significantly lower than that in control group in II lead (P < 0.05). The Tp-Te/QTc in PPS group was significantly lower than that in control group in II and aVR lead (P < 0.05). There was no significant difference in Tp-Te between PPS group and control group (P > 0.05). ② The Tp-Te in VVS group was significantly higher than that in control group in aVR, aVF, and V4 lead (P < 0.05). The Tp-Te/QT in VVS group was significantly higher than that in control group in aVF lead (P < 0.05). The Tp-Te/QTc in VVS group was significantly higher than that in control group in aVL, aVF and V1 lead (P < 0.05). ③ The Tp-Te, Tp-Te/QT in PPS group were significantly lower than those in VVS group in some leads (P < 0.05). The Tp-Te/QTc in PPS group was significantly lower than that in VVS group in some leads. (2) Orthostatic ECG: ① The Tp-Te in PPS group was significantly higher than that in control group in V1, V2 lead (P < 0.05). The Tp-Te/QT, Tp-Te/QTc in PPS group were significantly higher than those in control group in V2 lead (P < 0.05). ② The Tp-Te and Tp-Te/QTc in V4 lead, Tp-Te/QT in V1, V4 lead in VVS group were significantly higher than those in control group (P < 0.05). ③ The Tp-Te in PPS group was significantly lower than that in VVS group in some leads (P < 0.05). The Tp-Te/QT in PPS group was significantly lower than that in VVS group in some leads (P < 0.05). The Tp-Te/QTc in PPS group was significantly lower than that in VVS group in some leads. (3) The receiver-operating characteristic (ROC) curve analysis: Tp-Te of supine ECG and orthostatic ECG in some leads had a predictive value on diagnosis between PPS and VVS (P < 0.05). Tp-Te, Tp-Te/QT, and Tp-Te/QTc of supine and orthostatic ECG in some leads have a certain predictive value in the diagnosis between PPS and VVS in children.

Reducing Pain, Spasm, and Vasovagal Syndrome in Transradial Cardiac Angiography: The Role of Lidocaine Cream and Injectable Lidocaine

Background: Transradial cardiac angiography offers advantages in therapeutic outcomes and economic efficiency; however, it is associated with side effects such as pain, vascular spasm, and vasovagal syndrome. Objectives: This study evaluates the efficacy of injectable lidocaine, with and without the application of topical lidocaine cream, in mitigating these adverse effects. Methods: In this single-blinded clinical trial, 80 patients aged 18 and older who referred to Shahid Modarres Hospital, Tehran, Iran, between 2022 and 2023 were enrolled. Participants met specific criteria to ensure a homogeneous study population. They were randomly assigned to receive either lidocaine cream in conjunction with a subcutaneous lidocaine injection or a placebo cream with subcutaneous lidocaine. Pain intensity was assessed using the Visual Analog Scale (VAS), and complications were recorded through pre-designed checklists. Statistical analyses were performed using SPSS version 23, employing appropriate tests to explore significant differences. Results: The mean age of participants was 58.1 years, with both groups exhibiting similar demographic characteristics. Statistical analysis indicated that the use of lidocaine cream significantly reduced pain occurrence, with none in the experimental group reporting pain compared to 7 in the control group (P = 0.006). Furthermore, lidocaine cream decreased the incidence of spasms, noted in 5 patients in the control group, with no spasms reported in the experimental group (P = 0.021). Additionally, vasovagal syndrome was significantly lower in the experimental group (P = 0.011). Conclusions: The study indicates that pre-application of lidocaine cream prior to injectable lidocaine effectively alleviates pain, vascular spasm, and vasovagal syndrome in patients undergoing transradial cardiac angiography, supporting its incorporation into routine practice to enhance patient comfort and safety.

Cardiac Geometry and Function in Patients with Reflex Syncope.

Reflex syncope (RS) is the most prevalent form of syncope, yet its pathophysiology and clinical presentation are not well understood. Despite controversy, the 'ventricular theory' remains the most plausible hypothesis to explain RS in susceptible patients. Certain assumptions regarding the geometry and function of the heart are essential in supporting this theory. Given these considerations, the goal of this review was to try to integrate data on heart morphology and function in a phenotype of a patient susceptible to RS. Previous research suggests that a small left ventricle and atria, in addition to a normo- or hypercontractile myocardium, predispose to more syncopal events. These findings have been confirmed in different subsets of patients, including those with small heart and chronic fatigue syndrome, highlighting common pathophysiologic pathways in these subgroups of population. Heart geometry and function seem to play a role in different treatment strategies for RS patients, including the administration of medications, pacing, and possibly cardioneural ablation. In addition, parameters related to the geometry of the heart chambers and of the electrical activation of the heart seem to have predictive value for syncope recurrence. These parameters could be included in the future and improve the accuracy of predictive models for RS.