Search Results (43)

Background: When conservative therapies are insufficient for vasovagal syncope (VVS), procedural options such as permanent pacemakers or catheter ablation of ganglionated plexi (GP) may be considered. This meta-analysis aimed to evaluate the efficacy of GP catheter ablation in patients with VVS. Methods: A comprehensive literature search was performed in PubMed, Embase, and the Cochrane Library from 15 March 2024 to 10 May 2025. After duplicate removal, two reviewers independently screened studies and assessed full texts based on predefined criteria. A single-arm proportion meta-analysis was conducted. Results: Thirty-seven studies comprising 1585 participants were included. The pooled proportion of VVS recurrence after ablation was 8.9% (95% CI, 6.4–11.4%), but with substantial heterogeneity (I² = 74.4%, p < 0.001). Sensitivity and subgroup analyses confirmed the robustness of the pooled estimate. A meta-regression was performed to further explore potential effect modifiers, but no covariate reached statistical significance. Conclusions: This meta-analysis suggests that ganglionated plexi catheter ablation may be associated with a reduced recurrence of vasovagal syncope in selected populations. However, the findings are based predominantly on non-randomized observational studies, and the high between-study heterogeneity limits the strength of inference. Future randomized controlled trials with standardized methodologies are needed to confirm the long-term efficacy and safety of this intervention. Full article

Aim: The aim of this study was to evaluate choroidal and peripapillary retinal nerve fiber layer (RNFL) thicknesses in individuals with vasovagal syncope (VVS). Method: A total of 67 consecutive patients with VVS and 61 healthy control subjects were enrolled this study. The choroidal thickness (CT) at the fovea, the nasal to fovea thickness, and the temporal to fovea thickness were measured, alongside pRNLFT measurements assessed by swept-source optical coherence tomography (SS-OCT). Results: The mean foveal CT (408.7 ± 92.5 μm vs. 342.1 ± 60.2 μm, p < 0.01), the mean nasal CT (385.2 ± 88.3 μm vs. 329.2 ± 47.6 μm, p < 0.001), and the mean temporal CT (379.5 ± 51.6 μm vs. 321.48 ± 43.2 μm, p < 0.03) were statistically thicker in patients with VVS compared to the healthy controls. There was no statistically significant difference in the global pRNFLT measurements and all quadrants between the study groups. Conclusions: The CT in all regions was found to be thicker in patients with VVS compared to the healthy controls, while there were no differences in pRNFLT values. These results suggest that choroidal circulation might be affected by local neurotransmitter alterations in patients with VVS. Full article

Background: This paper will identify the potential genetic causes of multimorbidity associated with autosomal dominant congenital cataract (ADCC). Methods: Whole exome sequencing (WES) was performed on 13 individuals affected with ADCC. Subsequent bioinformatic analyses identified variants with deleterious pathogenicity scores. Results: Disease-causing variants were identified in 8 genes already linked to cataract (CHMP4B, CRYAA, CRYBA1, CRYGD, CYP21A2, GJA8, OPA1, and POMGNT1), but variants previously associated with systemic disorders were also found in a further 11 genes (ACTL9, ALDH18A1, CBS, COL4A3, GALT, LRP5, NOD2, PCK2, POMT2, RSPH4A, and SMO). All variants were identified via pipeline data analysis, prioritising rare coding variants using Kaviar and the Genome Aggregation Database. The following ADCC-associated non-ocular phenotypes were identified in four patients in the cohort: (i) Horner’s pupils, vaso-vagal syncope, and paroxysmal orthostatic tachycardia syndrome; (ii) reduced kidney function and high cholesterol; (iii) hypertension, high cholesterol, and kidney stones; and (iv) grade 1 spondylolysis. Conclusions: We report 11 novel genes identified in an ADCC patient cohort associated with systemic disorders found, along with 8 known cataract-causing genes. Our findings broaden the spectrum of potentially cataract-associated genes and their related lens phenotypes, as well as evidence multimorbidities in four patients, highlighting the importance of careful multisystem phenotyping following genetic analysis. Full article

Background: This study aimed to identify the risk factors associated with malignant vasovagal syncope (VVS), a rare yet clinically significant subtype of VVS. Methods: This single-center case–control study enrolled children diagnosed with malignant VVS, and the malignant VVS patients were matched in a 1:4 ratio with non-asystolic VVS children as a control group through age and sex stratification. Clinical characteristics and heart rate variability (HRV) parameters were analyzed. Binary logistic regression analyses were used to identify the risk factors significantly associated with malignant VVS. Results: A total of 10 patients in the malignant group and 40 children in the control group were included. The malignant group exhibited earlier symptom onset (7.0 ± 2.7 vs. 9.7 ± 2.7 years, p < 0.05) than the control group, and children in the malignant group had a higher prevalence of central triggers (60.0% vs. 17.5%, p < 0.05) and convulsive/incontinence episodes (80.0% vs. 17.5%, p < 0.05) than the control group. Additionally, the malignant group demonstrated significantly elevated HRV parameters, including very low frequency (VLF), low frequency (LF), and high frequency (HF), indicating substantial autonomic dysregulation characterized by parasympathetic predominance. Central triggers (OR = 7.16, 95%CI 1.10–46.73) and convulsive/incontinence manifestations (OR = 19.02, 95%CI 2.81–128.64) were independent risk factors of malignant VVS. Conclusions: The age at syncope onset was significantly earlier in children with malignant VVS, and children with malignant VVS exhibited profound autonomic dysregulation characterized by significant parasympathetic predominance. Finally, children with episodes induced by central triggers and accompanied by incontinence or convulsions were at a higher risk of asystole. Full article

Objectives: Syncope is a common cause of the transient loss of consciousness, with neurally mediated syncope (NMS) and particularly vasovagal syncope (VVS) being the most prevalent types among older children and adolescents. VVS is primarily caused by heightened parasympathetic activity triggered by emotional or postural stimuli, resulting in a temporary disruption of circulation. Although anamnesis and physical examination play key roles in diagnosing VVS, additional diagnostic methods are necessary in unclear cases. This study aims to evaluate the long-term outcomes of pediatric patients with syncope, focusing on clinical characteristics, diagnosis, and treatment approaches. Methods: A retrospective analysis was conducted on 455 pediatric patients aged 8–21 years who presented with syncope at our cardiology clinic between 2005 and 2023. Patients diagnosed with cardiac syncope, epilepsy, or postural orthostatic tachycardia syndrome (POTS) were excluded. The remaining 283 patients were categorized into two groups: those with confirmed VVS—based on a comprehensive evaluation, including medical history, physical examination, and electrocardiography—and those suspected of VVS who lack a confident diagnosis after an initial assessment requiring tilt table testing. Clinical features, diagnostic methods, and treatment outcomes were analyzed. Results: The study cohort had a mean age of 13.5 ± 1.6 years, with a female predominance of 69%. Among patients who underwent tilt table testing (TTT), 74.8% exhibited a positive response, with mixed-type syncope being the most prevalent (51%). Syncope recurrence was significantly higher in the TTT group (54%) compared to the clinically diagnosed group (15%) (p < 0.001). Relapse risk was strongly associated with the syncope subtype, particularly cardioinhibitory type 2B (OR: 2.3, 95% CI: 1.1–4, p < 0.01), and episode frequency (OR: 1.7, 95% CI: 1.3–2.5, p = 0.03). Beta-blocker therapy was selectively administered and demonstrated a reduced relapse risk in a univariate analysis. Conclusions: VVS is a significant health issue in pediatric patients and the therapeutic modalities available encompass various interventions, including modifications to lifestyle, adequate hydration, and pharmacological therapies. TTT was found to be an effective diagnostic tool for identifying high-risk patients and is recommended for appropriate cases in pediatric VVS diagnosis in accordance with the guidelines, with the objective of refining therapeutic methodologies and ultimately augmenting patient prognoses. Full article

Self-organized criticality (SOC) describes natural systems spontaneously tuned at equilibrium yet capable of catastrophic events or avalanches. The cardiovascular system, characterized by homeostasis and vasovagal syncope, is a prime candidate for SOC. Power laws are the cornerstone for demonstrating the presence of SOC. This study aimed to provide evidence of power-law behavior in cardiovascular dynamics. We analyzed beat-by-beat blood pressure and heart rate data from seven healthy subjects in the head-up position over 40 min. Cardiovascular avalanches were quantified by their duration (in beats), and symbolic sequences were identified. Five types of distributions were assessed for power-law behavior: Gutenberg–Richter, classical Zipf, modified Zipf, Zipf of time intervals between avalanches, and Zipf of symbolic sequences. A three-stage approach was used to show power laws: (1) regression coefficient r > 0.95, (2) comparison with randomized data, and (3) Clauset’s statistical test for power law. Numerous avalanches were identified (13.9 ± 0.8 per minute). The classical and modified Zipf distributions met all the criteria (r = 0.99 ± 0.00 and 0.98 ± 0.01, respectively), while the others showed partial agreement, likely due to the limited data duration. These findings reveal that Zipf’s distributions of cardiovascular avalanches strongly support SOC, shedding light on the organization of this complex system. Full article

Introduction: Vasovagal syncope is a prevalent condition marked by transient loss of consciousness due to abrupt decreases in systemic blood pressure and/or heart rate. Despite its clinical impact, the underlying haemodynamic mechanisms remain poorly defined, and data on age-related differences are limited and sometimes contradictory. Objectives: This study aimed to characterise haemodynamic adaptation patterns during a head-up tilt (HUT) test in adult (≥18 years) and paediatric (<18 years) patients with recurrent reflex syncope, compared with healthy adult controls. We sought to identify distinct temporal haemodynamic signatures and clarify potential age-related differences in syncope mechanisms. Methods: In this prospective observational study, participants underwent continuous beat-to-beat monitoring of cardiac output (CO), stroke volume (SV), heart rate (HR), and total peripheral resistance (TPR) during HUT. Linear mixed-effects models were used to examine time-by-group interactions, and post-hoc analyses were adjusted for multiple comparisons. Effect sizes and confidence intervals (CIs) were reported to quantify the magnitude of differences. Results: A total of 187 fainters (paediatric n = 81, adult n = 106) and 108 non-fainters (including 30 healthy controls) were studied. Compared to adult fainters, paediatric fainters showed a 24% larger decline in CO from baseline (mean difference of 1.1 L/min [95% CI: 0.5–1.7], p = 0.003) and a 15–20 bpm higher peak HR (p = 0.001) during presyncope. Both subgroups experienced significant drops in TPR, which were more pronounced in paediatric fainters (effect size = 0.27, 95% CI: 0.12–0.42). Non-fainters (including controls) maintained relatively stable haemodynamics, with no significant decrease in CO or TPR (p > 0.05). Age-related comparisons indicated a heavier reliance on HR modulation in paediatric fainters, leading to an earlier transition from compensated to pre-syncopal states. Conclusions: These findings demonstrate that paediatric fainters exhibit more abrupt decreases in CO and TPR than adults, alongside higher HR responses during orthostatic stress. Targeted interventions that address this heightened chronotropic dependency—such as tilt-training protocols or strategies to improve venous return—may be particularly beneficial in younger patients. An age-specific approach to diagnosis and management could improve risk stratification, minimise recurrent episodes, and enhance patient outcomes. Full article

A 1-year-old Maltese–Poodle mixed breed dog was referred to the cardiology service because of severe exercise intolerance and daily exercise-induced syncopal episodes. Physical examination revealed no abnormalities. Echocardiography showed intermittent underfilling of the heart. Abdominal ultrasound examination revealed a segmental aplasia of the caudal vena cava between the kidneys and the liver, and azygos continuation of the cava. The azygos vein dorsal to the right kidney showed a severe aneurysm with stasis of blood. Computed tomographic angiography showed that the right crus of the diaphragm was probably responsible for the intermittent compression of the dilated azygos vein, which was thought to have subsequently led to insufficient venous return to the heart. The underfilled ventricles could not produce sufficient cardiac output, which caused the assumed cerebral hypoperfusion due to presumed systemic arterial hypotension. Under general anesthesia a self-expanding nitinol stent was implanted into the azygos vein at the level of the diaphragm. All clinical signs resolved immediately after surgery. The dog remained free from clinical signs (6 months after surgery). This is the first report that describes the successful treatment of this congenital vascular anomaly. Ultrasonography of the caudal vena cava should be performed in dogs with unexplained syncope. Full article

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. Full article

Background: 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). Methods: 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. Results: 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. Conclusions: Pediatric patients with VVS can benefit from orthostatic training using a visual predictive model comprising age and rMSSD. Full article

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). Full article

Phobias are characterized as the excessive or irrational fear of an object or situation, and specific phobias affect about 10% of the world population. Blood-injection-injury phobia is a specific phobia that has a unique physical response to phobic stimuli, that is, a vasovagal syncope that causes the person to faint. Phobos is a serious game intended for blood phobia treatment that was created to be played in virtual reality with an HTC Vive that has photorealistic graphics to provide a greater immersion. We also developed a console application in C# for electrocardiography sensor connectivity and data acquisition, which gathers a 1 min baseline reading and then has continuous data acquisition during gameplay. Usability tests were conducted with self-reported questionnaires and with a case study population of 10 testers, which gave insight into the previous game experience of the tester for both digital games and virtual reality games, evaluating the discomfort for hardware on both the sensor and the virtual reality headset, as well as the game regarding usability, user experience, level of immersion, and the existence of motion sickness and its source. The results corroborate that the immersion of the game is good, which suggests that it will help with triggering the phobia. Full article

Syncope is a highly prevalent clinical condition characterized by a rapid, complete, and brief loss of consciousness, followed by full recovery caused by cerebral hypoperfusion. This symptom carries significance, as its potential underlying causes may involve the heart, blood pressure, or brain, leading to a spectrum of consequences, from sudden death to compromised quality of life. Various factors contribute to syncope, and adhering to a precise diagnostic pathway can enhance diagnostic accuracy and treatment effectiveness. A standardized initial assessment, risk stratification, and appropriate test identification facilitate determining the underlying cause in the majority of cases. New technologies, including artificial intelligence and smart devices, may have the potential to reshape syncope management into a proactive, personalized, and data-centric model, ultimately enhancing patient outcomes and quality of life. This review addresses key aspects of syncope management, including pathogenesis, current diagnostic testing options, treatments, and considerations in the geriatric population. Full article

Vasovagal syncope (VVS) refers to a heterogeneous group of conditions whereby the cardiovascular reflexes normally controlling the circulation are interrupted irregularly in response to a trigger, resulting in vasodilation, bradycardia, or both. VVS affects one-third of the population at least once in their lifetime or by the age of 60, reduces the quality of life, and may cause disability affecting certain routines. It poses a considerable economic burden on society, and, despite its prevalence, there is currently no proven pharmacological treatment for preventing VVS. The novel procedure of ganglionated plexus (GP) ablation has emerged rapidly in the past two decades, and has been proven successful in treating syncope. Several parameters influence the success rate of GP ablation, including specific ablation sites, localization and surgical techniques, method of access, and the integration of other interventions. This review aims to provide an overview of the existing literature on the physiological aspects and clinical effectiveness of GP ablation in the treatment of VVS. Specifically, we explore the association between GPs and VVS and examine the impact of GP ablation procedures as reported in human clinical trials. Our objective is to shed light on the therapeutic significance of GP ablation in eliminating VVS and restoring normal sinus rhythm, particularly among young adults affected by this condition. Full article

To systematically summarize the evidence of head-up tilt sleeping (HUTS) on orthostatic tolerance, we conducted a systematic, predefined search in PubMed, OVID Embase, Cochrane and Web of Science. We included studies assessing the effect of HUTS on orthostatic tolerance and other cardiovascular measures and rated the quality with the American Academy of Neurology risk of bias tool. We included 10 studies (n = 185) in four groups: orthostatic hypotension (OH; 6 studies, n = 103), vasovagal syncope (1 study, n = 12), nocturnal angina pectoris (1 study, n = 10) and healthy subjects (2 studies, n = 58). HUTS duration varied (1 day–4 months) with variable inclinations (5°–15°). In two of six OH studies, HUTS significantly improved standing systolic blood pressure. Orthostatic tolerance was consistently enhanced in OH studies with higher angles (≥12°), in 2 out of 3 with smaller angles (5°) but also in one studying horizontal sleeping. In vasovagal syncope, HUTS significantly augmented resilience to extreme orthostatic stress. One study was rated as a class II risk of bias, one of Class II/III and eight of Class IV. The evidence favouring HUTS to improve orthostatic tolerance is weak due to variable interventions, populations, small samples and a high risk of bias. Despite this, we found some physiological signs suggesting a beneficial effect. Full article