BACKGROUND: Lead dislodgements, tricuspid valve failure, and wound infections are prominent issues addressed by leadless pacemakers (LPM). These devises have emerged as viable alternatives to conventional transvenous pacemakers. LPMs offer minimized complications and effective pacing, particularly beneficial for elderly patients with a low body mass index (BMI) who are at heightened infection of risk. The Micra AV leadless pacemaker was released in the US in 2020, featuring a VDD pacing mode akin to conventional pacemakers. It senses atrial activity to pace ventricular beats while maintaining the natural atrioventricular activation sequence. Micra AV achieves atrioventricular synchronization through mechanical sensing principles. Ongoing research aims to assess its efficacy, implantation feasibility, and clinical safety.
METHODS: An 83-year-old man with a history of syncope was the focus of this case study. An implantable cardiac monitor (ICM) recorded occasional high-degree atrioventricular block in the patient. Subsequently, the Micra AV was implanted via the left femoral vein, and its settings were adjusted in accordance with data obtained from the ICM. No significant issues regarding pacing threshold or impedance were found during the follow-up examinations post-surgery. Importantly, the patient experienced a noticeable reduction in symptoms compared to before the implantation.
CONCLUSIONS: This case underscores the significance of ICM monitoring in elucidating cardiac events leading to syncope and guiding appropriate treatment. It also highlights the successful outcomes and reliable implantation of the Micra AV for managing high-degree atrioventricular block. This study contributes to the growing body of evidence supporting the adoption of leadless pacemakers as a viable option for patients requiring cardiac pacing, particularly those vulnerable to complications associated with traditional pacemakers. It provides real-world evidence of Micra AV\'s efficacy and safety, further validating its role in clinical practice.

Observed and recorded in various forms since ancient times, \'syncope\' is often popularly called \'fainting\', such that the two terms are used synonymously. Syncope/fainting can be caused by a variety of conditions, including but not limited to head injuries, vertigo, and oxygen deficiency. Here, we draw on a large body of literature on syncope, including the role of a recently discovered set of specialized mammalian neurons. Although the etiology of syncope still remains a mystery, we have attempted to provide a comprehensive account of what is known and what still needs to be performed. Much of our understanding of syncope is owing to studies in the laboratory mouse, whereas evidence from human patients remains scarce. Interestingly, the cardioinhibitory Bezold-Jarisch reflex, recognized in the early 1900s, has an intriguing similarity to-and forms the basis of-syncope. In this review, we have integrated this minimal model into the modern view of the brain-neuron-heart signaling loop of syncope, to which several signaling events contribute. Molecular signaling is our major focus here, presented in terms of a normal heart, and thus, syncope due to abnormal or weak heart activity is not discussed in detail. In addition, we have offered possible directions for clinical intervention based on this model. Overall, this article is expected to generate interest in chronic vertigo and syncope/fainting, an enigmatic condition that affects most humans at some point in life; it is also hoped that this may lead to a mechanism-based clinical intervention in the future.

UNASSIGNED: Syncope is a serious consequence in patients with hypertrophic obstructive cardiomyopathy (HOCM). Percutaneous endocardial septal radiofrequency ablation (PESA) has emerged as a promising intervention to alleviate symptoms and enhance the quality of life for HOCM patients. However, little is known about the effects of PESA on syncope in HOCM. The authors aimed to study the effects of PESA on syncope in patients with HOCM.
UNASSIGNED: Nineteen patients with HOCM and syncope were enrolled. The left ventricular outflow tract gradient (LVOTG) of the patients was more than 50 mmHg despite medication. The participants underwent PESA under the guidance of intracardiac echocardiography (ICE) combined with a three-dimensional electrophysiological mapping system. The patients were followed for 3 (3-5.5) months.
UNASSIGNED: The mean age of the patients was 54.8±13.7 years. Out of the 19 participants, 7 (37%) were females. During the follow-up, the syncope was completely alleviated in 14 patients (73.7%) or the syncope episodes were reduced greater than or equal to 80% in 16 patients (84.2%). The mean NYHA functional class significantly improved from 2.2±0.7 at baseline to 1.7±0.6 during follow-up (P=0.002). The LVOTG and septal thickness showed a decreasing trend from baseline to follow-up (LVOTG: P=0.083, septal thickness: P=0.086).
UNASSIGNED: The authors\' investigation provides evidence supporting the effectiveness of PESA in reducing syncope episodes in patients with HOCM.

暂无摘要。

We present a unique case of an 80-year-old male who presented to our emergency department following cardiac defibrillation when he was found to be in polymorphic ventricular tachycardia (VT) after a syncopal event while at cardiac rehabilitation. He had known coronary artery disease and had a four-vessel coronary artery bypass graft (CABG) 20 years prior to presentation. He underwent left heart catheterization (LHC) two months prior to the syncopal event for worsening shortness of breath and the decision at that time was to proceed with medical management and intervene with redo-CABG if shortness of breath did not improve or progressively worsened. While admitted under our care after the polymorphic VT event, we faced the dilemma of whether to proceed with redo-CABG first since cardiac ischemia is a common cause of polymorphic VT or whether to insert an implantable cardioverter-defibrillator (ICD) before proceeding with redo-CABG. We present the current literature that addresses ICD implantation for secondary prevention and our approach to this complicated case.

OBJECTIVE: Prior case series showed promising results for cardioneuroablation in patients with vagally induced atrioventricular blocks (VAVBs). We aimed to examine the acute procedural characteristics and intermediate-term outcomes of electroanatomical-guided cardioneuroablation (EACNA) in patients with VAVB.
RESULTS: This international multicentre retrospective registry included data collected from 20 centres. Patients presenting with symptomatic paroxysmal or persistent VAVB were included in the study. All patients underwent EACNA. Procedural success was defined by the acute reversal of atrioventricular blocks (AVBs) and complete abolition of atropine response. The primary outcome was occurrence of syncope and daytime second- or advanced-degree AVB on serial prolonged electrocardiogram monitoring during follow-up. A total of 130 patients underwent EACNA. Acute procedural success was achieved in 96.2% of the cases. During a median follow-up of 300 days (150, 496), the primary outcome occurred in 17/125 (14%) cases with acute procedural success (recurrence of AVB in 9 and new syncope in 8 cases). Operator experience and use of extracardiac vagal stimulation were similar for patients with and without primary outcomes. A history of atrial fibrillation, hypertension, and coronary artery disease was associated with a higher primary outcome occurrence. Only four patients with primary outcome required pacemaker placement during follow-up.
CONCLUSIONS: This is the largest multicentre study demonstrating the feasibility of EACNA with encouraging intermediate-term outcomes in selected patients with VAVB. Studies investigating the effect on burden of daytime symptoms caused by the AVB are required to confirm these findings.

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: There is no universally followed protocol for managing Reflex Vasovagal syncope (VVS).
METHODS: VVS patients were treated with a 2 step protocol. Step I - counseling, hydration, physiotherapy, and Tadasana Yoga maneuver. Patients with ≥2 VVS recurrences were given step II care - intensification of step I, elastic stockings,and pharmacotherapy. Follow-up included assessment by periodic functional status questionnaires.
RESULTS: 157 patients (103 males & 54 females,mean age - 53 ± 20 years & mean LVEF - 62 ± 5%.) experienced 867 total events - 382 syncopal, and 485 near syncopal episodes over 14 ± 9 months. After step I protocol, the mean total, syncopal and near syncopal events declined from 5 ± 7 to 0.3 ± 1.2 (P < 0.0001), 3 ± 2 to 0.1 ± 0.4 (P < 0.0001) and 3 ± 6 to 0.2 ± 1.1 (P < 0.0001) respectively. Twenty (12.7%) patients had 53 event recurrences, 15- syncopal episodes in 7 and 38 near syncope events in 13. After step II, 5 patients had 14 events. At 33 ± 15 months, in 152 patients (96.8%) there were no recurrences and syncope was prevented in all (100%). The median total, syncopal and near syncopal events declined from 3 to 0,(p < 0.001) 2 to 0 (p < 0.001) and 1 to 0 (p < 0.001) respectively. There was an improvement in all the 3 quality of life parameters.
CONCLUSIONS: We demonstrate a simple and effective protocol that can be universally adopted to prevent VVS recurrences,with improvement in quality of life.

Syncope, a form of transient loss of consciousness, remains a complex medical condition for which adverse cardiovascular outcomes, including death, are of major concern but rarely occur. Current risk stratification algorithms have not completely delineated which patients benefit from hospitalization and specific interventions. Patients are often admitted unnecessarily and at high cost. Artificial intelligence (AI) and machine learning may help define the transient loss of consciousness event, diagnose the cause, assess short- and long-term risks, predict recurrence, and determine need for hospitalization and therapeutic intervention; however, several challenges remain, including medicolegal and ethical concerns. This collaborative statement, from a multidisciplinary group of clinicians, investigators, and scientists, focuses on the potential role of AI in syncope management with a goal to inspire creation of AI-derived clinical decision support tools that may improve patient outcomes, streamline diagnostics, and reduce health-care costs.

UNASSIGNED: Symptoms associated with severe aortic stenosis (AS) are used to guide management.
UNASSIGNED: The purpose of this study was to examine the pattern of symptoms, comorbidities, and cardiac damage in moderate and severe AS.
UNASSIGNED: A total of 846,198 echocardiographic investigations from 330,940 individuals aged >18 years were selected for the most recent echocardiogram, moderate or severe AS (mean gradient 20.0-39.9 mm Hg, aortic valve peak gradient 3.0-3.9 m/s and aortic valve area >1.0 cm2; or ≥ 40.0 mm Hg, ≥4.0 m/s or ≤1.0 cm2, respectively), and a cardiologist consultation. Natural Language Processing was applied to letters to extract comorbidities, dyspnea, chest pain, and syncope. Patients with prior aortic valve replacement were excluded.
UNASSIGNED: 2,213 patients (0.7% overall, 32.8% females) had moderate and 3,416 (1.0%, 47.3% females) had severe AS. Comorbidities were common, including hypertension, (56.6% moderate AS, 53.1% severe AS, P = 0.01), coronary disease (46.0% and 46.8%, respectively, P = 0.58) and atrial fibrillation (29.6% and 34.8%, respectively, P < 0.001). Symptoms were also common in both moderate (n = 915, 41.3%) and severe (n = 1,630, 47.7%) AS (P < 0.001). Comorbidities were more likely in symptomatic vs asymptomatic patients (P < 0.001). Dyspnea was more likely in severe AS, whereas angina and syncope were similar in moderate vs severe AS. In multivariable analysis, only dyspnea was associated with severe (vs moderate) AS (OR: 1.73, 95% CI: 1.41-2.13, P < 0.001). In both adjusted and unadjusted models, the degree of cardiac damage did not relate to presence of any symptoms but was associated with AS severity.
UNASSIGNED: Dyspnea is common in both moderate and severe AS, is associated with comorbidities and is not related to the degree of cardiac damage. Symptom-guided management decisions in AS may need revision.