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Biomedical Engineering Online Mar 2024The diagnostic test for vasovagal syncope (VVS), the most common cause of syncope is head-up tilt test (HUTT) assessment. During the test, subjects experienced clinical...
BACKGROUND
The diagnostic test for vasovagal syncope (VVS), the most common cause of syncope is head-up tilt test (HUTT) assessment. During the test, subjects experienced clinical symptoms such as nausea, sweating, pallor, the feeling of palpitations, being on the verge of passing out, and fainting. The study's goal is to develop an algorithm to classify VVS patients based on physiological signals blood pressure (BP) and electrocardiography (ECG) obtained from the HUTT.
METHODS
After 10 min of supine rest, the subject was tilted at a 70-degree angle on a tilt table for approximately a total of 35 min. 400 µg of glyceryl trinitrate (GTN) was administered sublingually after the first 20 min and monitoring continued for another 15 min. Mean imputation and K-nearest neighbors (KNN) imputation approaches to handle missing values. Next, feature selection techniques were implemented, including genetic algorithm, recursive feature elimination, and feature importance, to determine the crucial features. The Mann-Whitney U test was then performed to determine the statistical difference between two groups. Patients with VVS are categorized via machine learning models including Support Vector Machine (SVM), Gaussian Naïve Bayes (GNB), Multinomial Naïve Bayes (MNB), KNN, Logistic Regression (LR), and Random Forest (RF). The developed model is interpreted using an explainable artificial intelligence (XAI) model known as partial dependence plot.
RESULTS
A total of 137 subjects aged between 9 and 93 years were recruited for this study, 54 experienced clinical symptoms were considered positive tests, while the remaining 83 tested negative. Optimal results were obtained by combining the KNN imputation technique and three tilting features with SVM with 90.5% accuracy, 87.0% sensitivity, 92.7% specificity, 88.6% precision, 87.8% F1 score, and 95.4% ROC (receiver operating characteristics) AUC (area under curve).
CONCLUSIONS
The proposed algorithm effectively classifies VVS patients with over 90% accuracy. However, the study was confined to a small sample size. More clinical datasets are required to ensure that our approach is generalizable.
Topics: Humans; Child; Adolescent; Young Adult; Adult; Middle Aged; Aged; Aged, 80 and over; Syncope, Vasovagal; Artificial Intelligence; Bayes Theorem; Tilt-Table Test; Electrocardiography
PubMed: 38555421
DOI: 10.1186/s12938-024-01229-9 -
Europace : European Pacing,... Mar 2024The term non-cardiac syncope includes all forms of syncope, in which primary intrinsic cardiac mechanism and non-syncopal transient loss of consciousness can be ruled...
The term non-cardiac syncope includes all forms of syncope, in which primary intrinsic cardiac mechanism and non-syncopal transient loss of consciousness can be ruled out. Reflex syncope and orthostatic hypotension are the most frequent aetiologies of non-cardiac syncope. As no specific therapy is effective for all types of non-cardiac syncope, identifying the underlying haemodynamic mechanism is the essential prerequisite for an effective personalized therapy and prevention of syncope recurrences. Indeed, choice of appropriate therapy and its efficacy are largely determined by the syncope mechanism rather than its aetiology and clinical presentation. The two main haemodynamic phenomena leading to non-cardiac syncope include either profound hypotension or extrinsic asystole/pronounced bradycardia, corresponding to two different haemodynamic syncope phenotypes, the hypotensive and bradycardic phenotypes. The choice of therapy-aimed at counteracting hypotension or bradycardia-depends on the given phenotype. Discontinuation of blood pressure-lowering drugs, elastic garments, and blood pressure-elevating agents such as fludrocortisone and midodrine are the most effective therapies in patients with hypotensive phenotype. Cardiac pacing, cardioneuroablation, and drugs preventing bradycardia such as theophylline are the most effective therapies in patients with bradycardic phenotype of extrinsic cause.
Topics: Humans; Bradycardia; Syncope; Syncope, Vasovagal; Hypotension; Hypotension, Orthostatic
PubMed: 38529800
DOI: 10.1093/europace/euae073 -
Open Access Journal of Contraception 2024Intrauterine devices (IUDs) are a widely used contraceptive. Possible complications from IUDs include failed insertion, pain, vasovagal reaction, infection, abnormal... (Review)
Review
Intrauterine devices (IUDs) are a widely used contraceptive. Possible complications from IUDs include failed insertion, pain, vasovagal reaction, infection, abnormal bleeding, and expulsion. Uterine perforation and migration of the IUD are rare complications occurring in approximately 1-2 per 1000 insertions. We executed a systematic review by reviewing all case reports and case series on IUD migration, published between December 2002 and December 2022. Our review indicates that about half of these patients present with pain and that a third are completely asymptomatic. The most common sites of migration are the intestine, bladder, and omentum. We found that the preferred method for removing the migrated IUD is laparoscopy. Generally, there are no lasting injuries after the removal of the migrated IUD, but occasionally, severe complications have been reported. Healthcare providers should be vigilant about this rare complication, especially in cases of painful insertion or the presence of other risk factors for perforation. When uterine perforation is diagnosed, it is advisable to remove the IUD to prevent severe complications.
PubMed: 38495451
DOI: 10.2147/OAJC.S458156 -
Italian Journal of Pediatrics Mar 2024Orthostatic intolerance, which includes vasovagal syncope and postural orthostatic tachycardia syndrome, is common in children and adolescents. Elevated plasma...
BACKGROUND
Orthostatic intolerance, which includes vasovagal syncope and postural orthostatic tachycardia syndrome, is common in children and adolescents. Elevated plasma homocysteine levels might participate in the pathogenesis of orthostatic intolerance. This study was designed to analyze the plasma metabolomic profile in orthostatic intolerance children with high levels of plasma homocysteine.
METHODS
Plasma samples from 34 orthostatic intolerance children with a plasma homocysteine concentration > 9 µmol/L and 10 healthy children were subjected to ultra-high-pressure liquid chromatography and quadrupole-time-of-flight mass spectrometry analysis.
RESULTS
A total of 875 metabolites were identified, 105 of which were significantly differential metabolites. Choline, 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine, 1-(1Z-octadecenyl)-2-(4Z,7Z,10Z,13Z,16Z,19Z-docosahexaenoyl)-sn-glycero-3-phosphocholine, histidine, isocitric acid, and DL-glutamic acid and its downstream metabolites were upregulated, whereas 1-palmitoyl-sn-glycero-3-phosphocholine, 1-stearoyl-sn-glycerol 3-phosphocholine, sphingomyelin (d18:1/18:0), betaine aldehyde, hydroxyproline, and gamma-aminobutyric acid were downregulated in the orthostatic intolerance group compared with the control group. All these metabolites were related to choline and glutamate. Heatmap analysis demonstrated a common metabolic pattern of higher choline, 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine, and DL-glutamic acid, and lower sphingomyelin (d18:1/18:0), 1-stearoyl-sn-glycerol 3-phosphocholine, and 1-palmitoyl-sn-glycero-3-phosphocholine in patients with certain notable metabolic changes (the special group) than in the other patients (the common group). The maximum upright heart rate, the change in heart rate from the supine to the upright position, and the rate of change in heart rate from the supine to the upright position of vasovagal syncope patients were significantly higher in the special group than in the common group (P < 0.05). Choline, 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine, and DL-glutamic acid were positively correlated with the rate of change in heart rate from the supine to the upright position in vasovagal syncope patients (P < 0.05).
CONCLUSIONS
The levels of choline-related metabolites and glutamate-related metabolites changed significantly in orthostatic intolerance children with high levels of plasma homocysteine, and these changes were associated with the severity of illness. These results provided new light on the pathogenesis of orthostatic intolerance.
Topics: Adolescent; Child; Humans; Orthostatic Intolerance; Syncope, Vasovagal; Glutamic Acid; Glycerylphosphorylcholine; Phosphorylcholine; Sphingomyelins; Choline; Homocysteine; Glycerol
PubMed: 38486257
DOI: 10.1186/s13052-024-01601-4 -
Internal Medicine (Tokyo, Japan) May 2024A 74-year-old woman presented to our hospital with syncope after a coronavirus disease 2019 (COVID-19) infection. Upon admission, she passed out, and an 8 second sinus...
A 74-year-old woman presented to our hospital with syncope after a coronavirus disease 2019 (COVID-19) infection. Upon admission, she passed out, and an 8 second sinus arrest was detected during telemetry monitoring. During the next syncope episode, telemetry monitoring showed that her heart rate decreased from 80 to 36 bpm, accompanied by a 2.4 second pause. A permanent pacemaker was implanted; however, the patient still experienced syncope. The head-up tilt test revealed a vasodepressor reflex syncope. The need for permanent pacemakers in patients with syncope following COVID-19 therefore remains controversial.
Topics: Humans; COVID-19; Aged; Female; Syncope; Pacemaker, Artificial; SARS-CoV-2; Tilt-Table Test; Telemetry; Syncope, Vasovagal
PubMed: 38432984
DOI: 10.2169/internalmedicine.3324-23 -
Missouri Medicine 2024Athletes are generally healthy but might have certain cardiac disorders which might, during athletic participation or training, result in cardiac symptoms including...
Athletes are generally healthy but might have certain cardiac disorders which might, during athletic participation or training, result in cardiac symptoms including syncope. Vasovagal syncope is probably the most common cause of syncope in athletes, but syncope in the context of these cardiac disorders might be a warning of sudden death.
Topics: Humans; Death, Sudden, Cardiac; Athletes; Syncope; Sports; Heart Diseases
PubMed: 38404441
DOI: No ID Found -
Clinical Autonomic Research : Official... Feb 2024Approximately 50% of patients with unexplained syncope and negative head-up tilt test (HUTT) who have an electrocardiogram (ECG) documentation of spontaneous syncope...
BACKGROUND
Approximately 50% of patients with unexplained syncope and negative head-up tilt test (HUTT) who have an electrocardiogram (ECG) documentation of spontaneous syncope during implantable loop recorder (ILR) show an asystolic pause at the time of the event.
OBJECTIVE
The aim of the study was to evaluate the age distribution and clinical predictors of asystolic syncope detected by ILR in patients with unexplained syncope and negative HUTT.
METHODS
This research employed a retrospective, single-center study of consecutive patients. The ILR-documented spontaneous syncope was classified according to the International Study on Syncope of Uncertain Etiology (ISSUE) classification.
RESULTS
Among 113 patients (54.0 ± 19.6 years; 46% male), 49 had an ECG-documented recurrence of syncope during the observation period and 28 of these later (24.8%, corresponding to 57.1% of the patients with a diagnostic event) had a diagnosis of asystolic syncope at ILR: type 1A was present in 24 (85.7%), type 1B in 1 (3.6%), and type 1C in 3 (10.7%) patients. The age distribution of asystolic syncope was bimodal, with a peak at age < 19 years and a second peak at the age of 60-79 years. At Cox multivariable analysis, syncope without prodromes (OR 3.7; p = 0.0008) and use of beta blockers (OR 3.2; p = 0.002) were independently associated to ILR-detected asystole.
CONCLUSIONS
In patients with unexplained syncope and negative HUTT, the age distribution of asystolic syncope detected by ILR is bimodal, suggesting a different mechanism responsible for asystole in both younger and older patients. The absence of prodromes and the use of beta blockers are independent predictors of ILR-detected asystole.
Topics: Humans; Male; Young Adult; Adult; Middle Aged; Aged; Female; Retrospective Studies; Age Distribution; Syncope; Heart Arrest; Electrocardiography; Electrocardiography, Ambulatory
PubMed: 38402334
DOI: 10.1007/s10286-024-01021-8 -
International Journal of Cardiology.... Apr 2024Cardioneuroablation (CNA) is an ablation technique that targets epicardial ganglionic plexi to reduce syncope burden and avoid pacemaker implantation in patients with...
BACKGROUND
Cardioneuroablation (CNA) is an ablation technique that targets epicardial ganglionic plexi to reduce syncope burden and avoid pacemaker implantation in patients with cardioinhibitory vasovagal syncope (VVS). This study aims to demonstrate feasibility and safety of CNA in high-risk refractory VVS patients using continuous monitoring with an implantable loop recorder (ILR).
METHODS
Data was collected prospectively for patients undergoing CNA. Patients were required to have recurrent syncope with documented asystole, refractory to conservative measures. Ganglionic plexi (GPs) were identified by fragmented signals and high frequency stimulation (HFS). Ablation was performed until loss of positive response to HFS, Wenckebach cycle shortening was achieved, or an increase in sinus rate of > 20 bpm. Follow-up was performed through remote and clinic follow-up of their ILRs.
RESULTS
Between December 2020 and July 2023 six patients (mean age 29 ± 3, 67 % female)underwent CNA. The baseline heart rate and Wenckebach cycle length was 63.2 ± 15 bpm and 582 ms before and 91 ± 5 bpm and 358 ms after ablation respectively. During a median follow-up of 13.4 months, 3/5 patients had no further syncopal episodes, 1 had a recurrence, underwent repeat CNA with no further episodes at 1 year, and 1 had 5 syncopal events, which was a dramatic reduction from nearly daily episodes pre-CNA. There were no procedure related complications.
CONCLUSIONS
A dramatic reduction in documented pauses and syncope burden was noted post CNA. Appropriate patient selection with rigorous objective follow-up in an experienced center is necessary. Larger studies are required to confirm these findings.
PubMed: 38379634
DOI: 10.1016/j.ijcha.2024.101360 -
Europace : European Pacing,... Feb 2024A dual-chamber pacemaker with closed-loop stimulation (CLS) mode is effective in reducing syncopal recurrences in patients with asystolic vasovagal syncope (VVS). In...
AIMS
A dual-chamber pacemaker with closed-loop stimulation (CLS) mode is effective in reducing syncopal recurrences in patients with asystolic vasovagal syncope (VVS). In this study, we explored the haemodynamic and temporal relationship of CLS during a tilt-induced vasovagal reflex.
METHODS AND RESULTS
Twenty patients underwent a tilt test under video recording 3.9 years after CLS pacemaker implantation. Three patients were excluded from the analysis because of no VVS induced by the tilt test (n = 1) and protocol violation (n = 2). In 14 of the remaining 17 patients, CLS pacing emerged during the pre-syncopal phase of circulatory instability when the mean intrinsic heart rate (HR) was 88 ± 12 b.p.m. and systolic blood pressure (SBP) was 108 ± 19 mmHg. The CLS pacing rate thereafter rapidly increased to 105 ± 14 b.p.m. within a median of 0.1 min [inter-quartile range (IQR), 0.1-0.7 min] when the SBP was 99 ± 21 mmHg. At the time of maximum vasovagal effect (syncope or pre-syncope), SBP was 63 ± 17 mmHg and the CLS rate was 95 ± 13 b.p.m. The onset of CLS pacing was 1.7 min (IQR, 1.5-3.4) before syncope or lowest SBP. The total duration of CLS pacing was 5.0 min (IQR, 3.3-8.3). Closed-loop stimulation pacing was not observed in three patients who had a similar SBP decrease from 142 ± 22 mmHg at baseline to 69 ± 4 mmHg at the time of maximum vasovagal effect, but there was no significant increase in HR (59 ± 1 b.p.m.).
CONCLUSION
The reproducibility of a vasovagal reflex was high. High-rate CLS pacing was observed early during the pre-syncopal phase in most patients and persisted, although attenuated, at the time of maximum vasovagal effect.
REGISTRATION
ClinicalTrials.gov identifier: NCT06038708.
Topics: Humans; Cardiac Pacing, Artificial; Hemodynamics; Pacemaker, Artificial; Reproducibility of Results; Syncope, Vasovagal; Tilt-Table Test
PubMed: 38340330
DOI: 10.1093/europace/euae045 -
Europace : European Pacing,... Feb 2024
Topics: Humans; Syncope, Vasovagal; Pacemaker, Artificial; Cardiac Pacing, Artificial; Hemodynamics
PubMed: 38340323
DOI: 10.1093/europace/euae046