UNASSIGNED: Exercise-induced complete atrioventricular block (EIAVB) is a rare cardiac conduction abnormality presenting challenges in diagnosis due to non-specific symptoms such as exertional dyspnoea, dizziness, and syncope.
UNASSIGNED: We present a case of a 76-year-old female with recurrent exercise-associated syncope. Non-invasive exercise testing played a crucial role in diagnosing her condition, revealing EIAVB and underscoring its importance in patients with cardiovascular risk factors.
UNASSIGNED: This case provides insight into the pathophysiology of EIAVB, including altered atrioventricular nodal refractoriness and exercise-induced ischaemic imbalances. It highlights the need for heightened clinical vigilance in diagnosing exercise-related syncope, especially in pre-existing cardiovascular conditions. This case underscores the critical importance of non-invasive testing for diagnosing EIAVB, highlighting the necessity of thorough evaluation in patients presenting with ambiguous symptoms and cardiovascular risks. Consequently, it advocates for adherence to guidelines to enhance outcomes and reduce the need for unnecessary invasive procedures.

BACKGROUND: Pulmonary embolisms (PEs) exhibit clinical features similar to those of acute coronary syndrome (ACS), including electrocardiographic abnormalities and elevated troponin levels, which frequently lead to misdiagnoses in emergency situations.
METHODS: Here, we report a case of PE coinciding with chronic coronary syndrome in which the patient\'s condition was obscured by symptoms mimicking ACS. A 68-year-old female with syncope presented to the hospital. Upon admission, she was found to have elevated troponin levels and an electrocardiogram showing ST-segment changes across multiple leads, which initially led to a diagnosis of ACS. Emergency coronary arteriography revealed occlusion of the posterior branches of the left ventricle of the right coronary artery, but based on the complexity of the intervention, the occlusion was considered chronic rather than acute. On the 3rd day after admission, the patient experienced recurrent chest tightness and shortness of breath, which was confirmed as acute PE by emergency computed tomography pulmonary angiography. Following standardized anticoagulation treatment, the patient improved and was subsequently discharged.
CONCLUSIONS: This case report highlights the importance of recognizing the nonspecific features of PE. Clinicians should be vigilant when identifying other clinical features that are difficult to explain accompanying the expected disease, and it is necessary to carefully identify the causes to prevent missed diagnoses or misdiagnoses.

BACKGROUND: Syncope is transient loss of consciousness, and in presyncope, patients experience same prodromal symptoms without losing consciousness. While studies have extensively reported the risk of serious outcome among emergency department (ED) syncope, the outcome for patients with presyncope and their management are not well studied. We undertook a systematic review to assess the occurrence/identification of short-term (30-day) serious outcomes among ED patients with presyncope.
METHODS: ED studies that enrolled patients with presyncope and reported any short-term serious outcome were included. Studies that enrolled patients without presyncope (e.g., hypoglycemia, seizure, and stroke) were excluded. We restricted our study to only English publications and searched the MEDLINE, Embase, Scopus, and Web of Science from the inception date to July 2023. We used SIGN 50 tool for assessment of risk of bias.
RESULTS: In total, 1788 articles were screened by two reviewers and 32 articles were selected for full-text assessment. Five (four prospective and one retrospective) studies with 2741 presyncope patients were included. Four studies were from North America and the fifth one was from Europe. Included studies had weaknesses due to risk of bias, but all had acceptable quality. The prevalence of overall adverse outcome varied 4.4%-26.8% for all adults and 5.5%-18.7% among older patients; arrhythmia was the most prevalent (17.4% in one study), followed by anemia/hemorrhage as reported in different studies. Among older patients, myocardial infarction was the third most common serious outcome reported in one study.
CONCLUSIONS: The prevalence of short-term serious outcomes varies from 4% to 27% among ED patients with presyncope in our review, with arrhythmia being the most common serious outcome. Our review indicates that presyncope may carry a similar risk to syncope, and hence, the same level of caution should be exercised for ED presyncope management as syncope.

BACKGROUND: The novel coronavirus of 2019 (COVID-19) has inflicted significant harm on the cardiovascular system. Patients presenting with fatal chronic arrhythmias after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are rare, arrhythmia caused by SARS-CoV-2 infection need to be taken seriously.
METHODS: Three female patients were admitted to the hospital with syncopal symptoms. Previously, they had been identified to have COVID-19 infection and none of the patients had a preexisting history of arrhythmia, and upon hospital admission, no electrolyte imbalances associated with arrhythmias were observed. However, following SARS-CoV-2 infection, patients exhibit varying degrees of syncope symptoms.
METHODS: A high-degree atrioventricular block was diagnosed after a comprehensive evaluation of the patient\'s clinical manifestations and electrocardiogram (ECG) performance.
METHODS: We performed ECG monitoring of the patient and excluded other causes of arrhythmia. The patient was discharged from the hospital after permanent pacemaker implantation and symptomatic treatment.
RESULTS: The outpatient follow-ups did not reveal a recurrence of syncope or complications related to the pacemaker in any of the three patients.
CONCLUSIONS: Some patients did not exhibit any obvious respiratory symptoms or signs following SARS-CoV-2 infection. This suggests that the cardiac conduction system may be the preferred target for some SARS-CoV-2 variants. Therefore, in addition to investigating the causes of malignant arrhythmias, special attention should be paid to SARS-CoV-2 infection in patients with developing arrhythmias. Additionally, permanent pacemaker implantation may be the most suitable option for patients who already have malignant arrhythmias.

BACKGROUND: Gaucher disease (GD) is a lysosomal storage disease that leads to the accumulation of glucocerebroside within reticuloendothelial cells, haematological, neurological, skeletal and abdominal organs. These clinical manifestations are common to all types of GD, but categorization depends on the absence of neurological involvement (type I) or its presence (type II and III). Cardiac involvement is rare and only reported in few cases, where valvular and aortic calcifications were associated with type IIIc. Other cardiac manifestations, such as constrictive pericarditis, pulmonary hypertension, myocardial infiltration, and restrictive cardiomyopathy, had also been reported.
METHODS: We report a case of a 72-year-old patient with known type 1 GD who presented with a sudden syncope during exercise. He reported also an exercise intolerance evolving for three months. Echocardiography found concentric left ventricular hypertrophy with segmental hypokinesis, bi-atrial enlargement, and mildly reduced ejection fraction. Mitral flow was in favour of grade II diastolic dysfunction with elevated filling pressure. Cardiac magnetic resonance (CMR) showed interstitial fibrosis in the basal infero-septal wall, probably due to the myocardial infiltration of GD. Due to the lack of echocardiographic and CMR hallmarks of cardiac GD, we conducted a literature review on similar findings.
CONCLUSIONS: This case illustrates the importance of non-invasive cardiac imaging in the diagnosis, prognosis and management of cardiac manifestations of GD.

BACKGROUND: Implantable loop recorders (ILRs) are increasingly used to evaluate patients with unexplained syncope. Identification of all predictors of bradycardic syncope and consequent permanent pacemaker (PPM) insertion is of substantial clinical interest as patients in the highest risk category may benefit from upfront pacemaker insertion.
OBJECTIVE: We performed a systematic review and meta-analysis to identify risk predictors for PPM insertion in ILR recipients with unexplained syncope.
METHODS: An electronic database search (MEDLINE, Embase, Scopus, Cochrane) was performed in June 2023. Studies evaluating ILR recipients with unexplained syncope and recording risk factors for eventual PPM insertion were included. A random effects model was used to calculate the pooled odds ratio (OR) for clinical and electrocardiographic characteristics with respect to future PPM requirement.
RESULTS: Eight studies evaluating 1007 ILR recipients were included; 268 patients (26.6%) underwent PPM insertion during study follow-up. PPM recipients were older (mean age, 70.2 ± 15.4 years vs 61.6 ± 19.7 years; P < .001). PR prolongation on baseline electrocardiography was a significant predictor of PPM requirement (pooled OR, 2.91; 95% confidence interval, 1.63-5.20). The presence of distal conduction system disease, encompassing any bundle branch or fascicular block, yielded a pooled OR of 2.88 for PPM insertion (95% confidence interval, 1.53-5.41). Injurious syncope and lack of syncopal prodrome were not significant predictors of PPM insertion. Sinus node dysfunction accounted for 62% of PPM insertions, whereas atrioventricular block accounted for 26%.
CONCLUSIONS: Approximately one-quarter of ILR recipients for unexplained syncope require eventual PPM insertion. Advancing age, PR prolongation, and distal conduction disease are the strongest predictors for PPM requirement.

Identifying the underlying cause of unexplained syncope is crucial for appropriate management of recurrent syncopal episodes. Implantable loop recorders (ILRs) have emerged as valuable diagnostic tools for monitoring patients with unexplained syncope. However, the predictors of pacemaker requirement in patients with ILR and unexplained syncope remain unclear. In this study, we shed light on these prognostic factors. PubMed/MEDLINE, EMBASE, Web of Science, and Cochrane CENTRAL were systematically searched until May 04, 2023. Studies that evaluated the predictors of pacemaker requirement in patients with implantable loop recorder and unexplained syncope were included. The \"Quality In Prognosis Studies\" appraisal tool was used for quality assessment. The pooled odds ratio (OR) with 95% confidence intervals (CIs) was calculated. The publication bias was evaluated using Egger\'s and Begg\'s tests. Ten studies (n = 4200) were included. Right bundle branch block (OR: 3.264; 95% CI: 1.907-5.588, p < .0001) and bifascicular block (OR: 2.969; 95% CI: 1.859-4.742, p < .0001) were the strongest predictors for pacemaker implantation. Pacemaker requirement was more than two times in patients with atrial fibrillation, sinus bradycardia and first degree AV block. Valvular heart disease, diabetes mellitus, and hypertension were also significantly more in patients with pacemaker implantation. Age (standardized mean difference [SMD]: 0.560; 95% CI: 0.410/0.710, p < .0001) and PR interval (SMD: 0.351; 95% CI: 0.150/0.553, p = .001) were significantly higher in patients with pacemaker requirement. Heart conduction disorders, atrial arrhythmias and underlying medical conditions are main predictors of pacemaker device implantation following loop recorder installation in unexplained syncopal patients.

Remote Monitoring (RM) has been shown to provide useful information about arrhythmic events in patients with implantable loop recorders (ILRs), however there is few and conflicting data about the false positive (FP) alarms burden and characteristics among ILR recipients. The aim of the present systematic review was to evaluate incidence and characteristics of FP alarms among ILR patients followed by RM. We developed a systematic research in Embase, MEDLINE and PubMed databases and selected all papers focused on false positive ILR transmissions published from June 1, 2013 to June 1, 2023. Case reports, meeting summaries, posters and simple reviews were excluded. Twelve reports were finally selected, including five prospective and seven retrospective studies. Information about population characteristics, device type and setting, overall transmissions and FP alarms and any adopted strategies to reduce them were extracted from an overall population of 3.305 patients. FP alarms were 59.7% of the overall remote transmissions and were found in 1/5 of the analyzed population. FP alarms for atrial fibrillation were the most common cause of false transmissions and were mainly due to premature atrial and ventricular complexes. No clinical predictors of FP alarms were identified, except for nonparasternal ILR implantation site. Since the overload work due to FP alarms might reduce the benefit of remote monitoring of ILR patients, the device optimization is an important step until an help from machine-learning algorithms is available.

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.

To review the available evidence on the impact of muscarinic receptor modulation on cardiovascular control in humans.
In this narrative Review we summarize data on cardiovascular endpoints from clinical trials of novel subtype-selective or quasi-selective muscarinic modulators, mostly PAMs, performed in the last decade. We also review the cardiovascular phenotype in recently described human genetic and autoimmune disorders affecting muscarinic receptors.
Recent advancements in the development of compounds that selectively target muscarinic acetylcholine receptors are expanding our knowledge about the physiological function of each muscarinic receptor subtype (M1, M2, M3, M4, M5). Among these novel compounds, positive allosteric modulators (PAMs) have emerged as the preferred therapeutic to regulate muscarinic receptor subtype function. Many muscarinic allosteric and orthosteric modulators (including but not limited to xanomeline-trospium and emraclidine) are now in clinical development and approaching regulatory approval for multiple indications, including the treatment of cognitive and psychiatric symptoms in patients with schizophrenia as well as Alzheimer\'s disease and other dementias. The results of these clinical trials provide an opportunity to understand the influence of muscarinic modulation on cardiovascular autonomic control in humans. While the results and the impact of each of these therapies on heart rate and blood pressure control have been variable, in part because the clinical trials were not specifically designed to measure cardiovascular endpoints, the emerging data is valuable to elucidate the relative cardiovascular contributions of each muscarinic receptor subtype.
Understanding the muscarinic control of cardiovascular function is of paramount importance and may contribute to the development of novel therapeutic strategies for treating cardiovascular disease.