Endocardial ablation of ganglionated plexus for the treatment of carotid sinus syndrome

INTRODUCTION

Carotid sinus syndrome (CSS), characterized by exaggerated vagal responses leading to asystolic pauses with carotid sinus massage (CSM), often necessitates pacemaker implantation. This study investigates cardioneuroablation (CNA) as an alternative strategy for CSS.

METHODS

Prospective study of consecutive patients referred for CNA due to CSS. All patients underwent CSM, atropine test and 24-h Holter monitoring before the procedure and at 6 months. The primary objective was the absence of any cardioinhibitory response to CSM following CNA. Secondary objectives included the combined endpoint of syncope and presyncope-free survival, pacemaker-free survival, differences in heart rate variation (HRV), as well as differences in the pre- and postprocedure atropine tests and in the SF-36 quality-of-life questionnaire.

RESULTS

A total of 13 consecutive patients (84.6% male, mean age 63.8 ± 12.3 years) were included. CSM revealed a symptomatic asystolic pause in all patients before CNA (7.3 [5.6-10.5] s). After the procedure, all the patients had a negative CSM, and only one patient (7.7%) had a positive CSM at 6 months. After a median follow-up of 11.2 (10.6-16.3) months, syncope or presyncope-free survival was 84.6%, and none required pacemaker implantation. There was an improvement in the energy and health change items in the SF-36 questionnaire. There was a reduction in HR increase in the atropine test at 6 months (pre-CNA: 66% [52-84] vs. post-CNA 26.0% (19.8-29.3]; p = .008) and in HRV parameters.

CONCLUSIONS

In this proof-of-efficacy study, performed in patients affected by asystolic CSS, CNA was effective in reducing the rate of cardioinhibitory responses, suggesting a potential efficacy in also reducing syncopal recurrences. Controlled trials are warranted to corroborate clinical findings.

Carotid Sinus Tumor-Induced Positional Bradycardia and Hypotension After Extubation: A Case Report

Regional progression of head and neck malignancies can lead to carotid sinus tumors, causing hemodynamic instability and carotid sinus syndrome (CSS). A 60-year-old male with tonsillar squamous cell carcinoma developed profound positional bradycardia and hypotension immediately after extubation following dental extraction. The patient developed recurrent episodes of positional bradycardia and hypotension, leading to eventual pacemaker placement. Further workup revealed a large mass in the left neck and necrotic cervical lymphadenopathy, indicating CSS from malignancy compression. This case highlights the need for consideration of CSS in patients with known head and neck malignancy, particularly when postural hypotension and bradycardia are present.

Air Pollution Role as Risk Factor of Cardioinhibitory Carotid Hypersensitivity

Little is known about the impact of air pollution on neuroautonomic system. The authors have investigated possible influence of air pollution and outdoor temperature on the carotid sinus hypersensitivity (CSH), as main cause of neurally mediated syncope in forty-years-old subjects and older. Pollutants’ concentrations and outdoor temperature of days in which 179 subjects with recurrent syncope underwent carotid sinus massage (CSM) were analyzed. Before this manoeuvre, cardiovascular control by short period heart and blood pressure spectral duration of segment between the end of P and R ECG-waves (PeR) were registred; RR variability on the same short period ECG recordings and their spectral coherence were also analyzed. CSH was found in 57 patients (28 with cardioinhibitory response and 29 subjects showed vasodepressor reaction), while 122 subjects had a normal response. CSM performed during high ozone concentrations was associated with slightly higher risk of cardioinhibitory response (odd ratio 1.012, 95% CI 1.001–1.023, p < 0.05), but neither this or other polluting agent nor outdoor temperature seemed to influence autonomic control in basal resting condition. Thus, ozone seemed to influence response to the CSM in CSH patients and it is probably able to facilitate a cardioinhibitory response, perhaps through an increase of nerve acetylcholine release. P→PR coherence could be useful in predicting a sinus cardioinhibitory hypersensitivity in those cases when CSM is contraindicated.

[Management of syncope in clinical practice : What has changed according to the new ESC guidelines 2018?]

Syncope is a common problem in clinical practice, which affects approximately 1% of patients admitted to European emergency departments. The clinical practice guidelines for the diagnosis and management of syncope published by the European Society of Cardiology (ESC) are based on the newest scientific data in the field and have provided clinical cardiologists with a structured therapeutic approach for affected patients over many years. The previous ESC guidelines on syncope were published in 2009 and are compared to the most recent edition, which was published in 2018. This review summarizes the most important innovations with respect to the diagnostic principles and treatment of syncope. The initial assessment of the patient and the risk stratification in the emergency department are the focus of the review. Another important topic that is adequately covered in the current guidelines is the rising significance of implantable loop recorders for the evaluation of unexplained syncope and the assessment of potential indications for a definitive treatment with a pacemaker or implantable cardioverter defibrillator (ICD). Additional changes involve the evidence level with respect to the use of other diagnostic (ECG monitoring, tilt testing) and therapeutic measures (indications for pacemaker implantation, catheter ablation of tachycardiac rhythm disorders).

Carotid sinus syndrome: Progress in understanding and management

Carotid sinus syndrome (CSS) is a disease of the autonomic nervous system presenting with syncope, especially in older males who often have cardiovascular disease. The aetiology is unknown and epidemiological data is limited. Forty new patients/million population have been estimated to require pacing for CSS and these patients represent ∼9% of those presenting syncope to a specialist facility. CSS is defined as a response to carotid sinus massage (CSM) that includes reproduction of spontaneous symptoms. Cardioinhibitory CSS shows 3s asystole on CSM and vasodepressor CSS shows >50 mmHg fall in blood pressure (BP), there are mixed forms. The methodology of CSM requires correct massage in the supine and upright with continuous ECG and BP. Assessment of the vasodepressor component implies the ‘method of symptoms’ using atropine to prevent asystole. Carotid sinus hypersensitivity (CSH) is a related condition where CSM is positive in an asymptomatic patient. CSH cannot be assumed to respond to pacing. CSS patients present syncope with little or no warning. If no cause is revealed by the initial evaluation, CSM should be considered in all patients >40 years. CSM carries a small risk of thromboembolism. Therapy for cardioinhibitory CSS is dual chamber pacing, which is most effective in patients with a negative tilt test. Syncope recurrence is ∼20% in 5 years in paced patients. Therapy for the vasodepressor component of CSS, as pure vasodepression or mixed, where tilt testing will likely be positive, is often unrewarding: alternative therapeutic measures may be needed including discontinuation/reduction of hypotensive drugs.

At the heart of the arterial baroreflex: a physiological basis for a new classification of carotid sinus hypersensitivity

The aim of this review is to provide an update of the current knowledge of the physiological mechanisms underlying reflex syncope. Carotid sinus syncope will be used as the classical example of an autonomic reflex with relatively well-established afferent, central and efferent pathways. These pathways, as well as the pathophysiology of carotid sinus hypersensitivity (CSH) and the haemodynamic effects of cardiac standstill and vasodilatation will be discussed. We will demonstrate that continuous recordings of arterial pressure provide a better understanding of the cardiovascular mechanisms mediating arterial hypotension and cerebral hypoperfusion in patients with reflex syncope. Finally we will demonstrate that the current criteria to diagnose CSH are too lenient and that the conventional classification of carotid sinus syncope as cardioinhibitory, mixed and vasodepressor subtypes should be revised because isolated cardioinhibitory CSH (asystole without a fall in arterial pressure) does not occur. Instead, we suggest that all patients with CSH should be thought of as being 'mixed', between cardioinhibition and vasodepression. The proposed stricter set of criteria for CSH should be evaluated in future studies.