Cardioinhibitory Carotid Sinus Syndrome Research Articles

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

Abstract 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 management strategy for CSS. Methods Prospective study of consecutive patients referred for CNA. All patients underwent CSM, atropine test, 24-hour Holter monitoring and SF-36 quality of life questionary before the procedure and at 6 months. The objective of the study was to assess syncope free survival, grade of cardioinhibition with CSM and heart rate variation (HRV) and quality of life after the procedure. Results A total of 13 patients (84.6% male, mean age 63.8 ± 12.3 years) were included. After a median follow-up of 9.2 (8.6-14.3) months, none of the patients experienced syncope (0%) and none of the patients required pacemaker implantation. After the procedure all the patients had a negative CSM and only one patient (7.7%) had a positive CSM at 6 months (Figure 1). There was an improvement in the energy and health change items in the SF-36 quality of life questionary. There was a reduction in HR increase in the atropine test at 6 months (pre-CNA: 66% (52-84) vs. post-CNA 27.4% (21.9-90.9); p=0.027) and in most of the 24-hour Holter monitoring HRV parameters (Figure 2). Conclusions Cardioneuroablation emerges as a promising and effective alternative to pacemaker implantation in managing cardioinhibitory CSS. Further research is warranted to solidify these findings and explore the long-term effects of CNA in this scenario.Maximum RR interval with CSMHeart rate increase in the atropine tes

Head-up tilt test induced asystole and recurrent syncope: a follow-up study

Abstract Introduction Head-up tilt test (HUTT) is a valuable diagnostic tool in unexplained and recurrent syncope, especially when reflex etiology is suspected. If asystole is the dominant feature of reflex syncope, permanent pacemaker therapy may be effective for reducing syncope recurrence. Purpose To investigate syncope recurrence, pacemaker implantation and death of patients with syncope and asystole induced by HUTT and carotid sinus message (CSM). Methods Retrospective analysis of consecutive patients referred for HUTT between January 2017 and December 2021 and selection of those with cardioinhibitory response, defined by syncope or pre-syncope and asystolic pause ≥3 seconds. Patients’ follow-up (FUP) was performed via a phone interview and analysis of clinical records, to assess recurrence of syncope, treatments, and death. Results A total of 44 patients were included: 30 (68,2%) were men, with a median age of 69 years (interquartile range (IQR) of 24). Asystole was experienced after CSMin 41 patients and during tilt test alone in 3 patients. Median FUP was 26 months (IQR 23). There were 19 (44,2%) patients who implanted pacemaker (PM), all with cardioinhibitory carotid sinus syndrome ( I-CSS), 57,9% men, with median age of 74 years (IQR 19) and median duration of asystole during CSMof 6,3 seconds (IQR 3,8). Of these, 5 (26,3%) implanted a unicameral PM and the remaininga bicameral PM, with AAI-DDD mode programming. Two patients had PM-related complications: infection and dislodgment of ventricular lead, both in the first 15 days after implantation. Median atrial and ventricular pacing percentage at last PM consultation was 7% (IQR 28) and 1% (IQR 4), respectively. There was a positive strong correlation between the percentage of atrial pacing at first and at last appointment (p<0,001, r=0,867) and a positive moderated correlation between the percentage of ventricular pacingat first and at last appointment (p=0,022, r=0,586), suggesting a similar degree of pacing along FUP-time. Only three patients (6,8%) had syncope recurrence, all men with CI-CSS, median age of 78; one patient had syncope before implantation PM, other relapsed 2-times with a PMimplanted and the third refused PMimplantation despite 5-time recurrence of symptoms. There was no association between the duration of the asystole during HUTT with implantation of PM nor syncope recurrence (p>0.2). Age at HUTT was significantly associated both with CI-CSS and PM implantation (p=0,001 and p=0,045, respectively). Two patients died, both of oncologic causes. Conclusion In agreement with the literature, our cohort of patients with cardioinhibitory response during HUTT and CSM experienced an overall good prognosis, with no cardiac deaths; there was very low syncope recurrence, not allowing a comparison between the groups with and without pacemaker. Age at HUTT was significantly associated both with CI-CSS and PMimplantation.

Cardioneuroablation for carotid sinus syndrome mediated by complete atrioventricular block.

Carotid sinus syndrome (CSS) is a rare condition leading to recurrent syncope. Permanent pacemaker implantation is the mainstay treatment of cardioinhibitory CSS. In this report, we present a CSS patient with reproducible atrioventricular block during carotid massage, who was treated with cardioneuroablation.

Cardioneuroablation for carotid sinus syndrome: a case series

Cardioinhibitory carotid sinus syndrome (CSS) is a neurally-mediated (reflex) syncope, secondary to excessive vagal response to carotid sinus pressure. A growing body of studies have shown that catheter ablation of ganglionated plexi (GPs) or cardioneuroablation (CNA) is effective in treating patients with vaso-vagal syncope (1). To date, no studies systematically evaluated CNA in patients with CSS.

Causes of syncopal recurrences in patients treated with permanent pacing for bradyarrhythmic syncope: Findings from the SYNCOPACED registry

Few studies have examined the causes of syncope/collapse recurrences in patients with a previously implanted pacemaker for bradyarrhythmic syncope. The purpose of this study was to assess the causes of syncope/collapse recurrences after pacemaker implantation for bradyarrhythmic syncope in a large patient population. The SYNCOpal recurrences in patients treated with permanent PACing for bradyarrhythmic syncope (SYNCOPACED) registry was a prospective multicenter observational registry enrolling 1364 consecutive patients undergoing pacemaker implantation for bradyarrhythmic syncope. During follow-up, the time to the first syncope/collapse recurrence was recorded. Patients with syncope/collapse recurrences underwent a predefined diagnostic workup aimed at establishing the mechanism of syncope/collapse. During a median follow-up of 50 months, 213 patients (15.6%) reported at least 1 syncope/collapse recurrence. The risk of syncope/collapse recurrence was highest in patients who underwent implantation for cardioinhibitory vasovagal syncope (26.4%), followed by unexplained syncope and chronic bifascicular block (21.5%), cardioinhibitory carotid sinus syndrome (17.2%), atrial fibrillation needing pacing (15.5%), atrioventricular block (13.6%), and sinus node disease (12.5%) (P = .017). The most frequent cause of syncope/collapse recurrence was reflex syncope (27.7%), followed by orthostatic hypotension (26.3%), pacemaker or lead malfunction (5.6%), structural cardiac disease (5.2%), and atrial and ventricular tachyarrhythmias (4.7% and 3.8%, respectively). In 26.8% of cases, the mechanism of syncope/collapse remained unexplained. In patients receiving a pacemaker for bradyarrhythmic syncope, reflex syncope and orthostatic hypotension are the most frequent mechanisms of syncope/collapse recurrence after implantation. Pacing system malfunction, structural cardiac diseases, and tachyarrhythmias are rare mechanisms. The mechanism remains unexplained in >25% of patients.

Incidence and predictors of syncope recurrence after cardiac pacing in patients with carotid sinus syndrome

BackgroundCardiac pacing is the treatment of choice for cardioinhibitory carotid sinus syndrome (CSS), but syncope recurrence occurs in up to 20% of patients within 3 years. The present study aims at assessing incidence and identifying predictors of syncope recurrence in patients receiving pacing therapy for CSS. MethodsThe Syncope Clinics of two large regional hospitals in Northern Italy, both following European Syncope Guidelines, combined to perform this study. Retrospective analysis of 3127 consecutive patients undergoing carotid sinus massage (CSM) was performed 2004–2014. Ten-second supine and standing CSM was systematically assessed in patients aged >40 years with suspected reflex syncope as part of the initial evaluation. Syncope recurrence was investigated in those paced for CSS having >6 months' available follow-up. Data were collected from clinical records and patient interviews. ResultsCSS was diagnosed in 261 patients (8.3%). Pacemakers were implanted in 158, with follow-up data available in 112: 19 (17%) experienced 73 syncope recurrences during a mean follow-up of 89 ± 42 months, yielding an incidence of 0.5 episodes per patient/year. Prodrome, predisposing situations preceding syncope and chronic nitrate therapy were more frequent in patients reporting recurrence. Prodrome and predisposing situations remained independent predictors of post-implantation recurrence on multivariable analysis. ConclusionsCSS is a frequent cause of syncope, if CSM is performed during the initial evaluation. Most patients treated by pacing remain asymptomatic during long-term follow-up. In those who have recurrence, its incidence is very low. Prodrome and predisposing situations are predictors of post-implantation recurrence, suggesting presence of hypotensive susceptibility.

Relationship Between Phosphate and Sodium Nitrite Ingestion and Vascular Hardness of Longevity Elderly Population in Okinawa Prefecture

Cardiac pacing is the treatment of choice for cardioinhibitory carotid sinus syndrome (CSS), but syncope recurrence occurs in up to 20% of patients within 3 years. The present study aims at assessing incidence and identifying predictors of syncope recurrence in patients receiving pacing therapy for CSS.The Syncope Clinics of two large regional hospitals in Northern Italy, both following European Syncope Guidelines, combined to perform this study. Retrospective analysis of 3127 consecutive patients undergoing carotid sinus massage (CSM) was performed 2004–2014. Ten-second supine and standing CSM was systematically assessed in patients aged >40 years with suspected reflex syncope as part of the initial evaluation. Syncope recurrence was investigated in those paced for CSS having >6 months' available follow-up. Data were collected from clinical records and patient interviews.CSS was diagnosed in 261 patients (8.3%). Pacemakers were implanted in 158, with follow-up data available in 112: 19 (17%) experienced 73 syncope recurrences during a mean follow-up of 89 ± 42 months, yielding an incidence of 0.5 episodes per patient/year. Prodrome, predisposing situations preceding syncope and chronic nitrate therapy were more frequent in patients reporting recurrence. Prodrome and predisposing situations remained independent predictors of post-implantation recurrence on multivariable analysis.CSS is a frequent cause of syncope, if CSM is performed during the initial evaluation. Most patients treated by pacing remain asymptomatic during long-term follow-up. In those who have recurrence, its incidence is very low. Prodrome and predisposing situations are predictors of post-implantation recurrence, suggesting presence of hypotensive susceptibility.

073_16760 Predictors of Syncopal Recurrence after Cardiac Pacing in Patients with Carotid Sinus Syndrome

In cardio-inhibitory Carotid Sinus Syndrome (CI-CSS), syncopal recurrence is expected to occur in up to the 20% of patients after pacing therapy. The present study analyzes post-implantation syncopal recurrence in CI-CSS, to identify predictors of recurrence. We retrieved electronic records

Cardioinhibitory Carotid Sinus Syndrome - a mathematical model.

Carotid sinus massage (CSM) is a simple clinical test for stimulating the carotid sinus reflex. During CSM, firm longitudinal massage is applied at the point of maximal pulsation over the carotid bifurcation resulting in relative bradycardia. CSM is used to diagnose Cardioinhibitory Carotid Sinus Syndrome (CICSS). CICSS is an age-related disorder, characterized by profound symptomatic cardioinhibition (> 3 seconds pause) following CSM. CICSS prevalence increases with age and is responsible for 1 to 20% of all pacemaker implantations per year. Treatment options for CSS are limited and much debate still remains around its underlying etiology. In this paper we present a first computer simulation of carotid sinus massage (CSM) in older adults and demonstrate its ability to simulate normal heart rate responses to CSM. Importantly we demonstrate that our mathematical model requires inclusion of model elements to simulate autonomic control of perinodal T-cell activity in order to replicate the profound cardioinhibitory response observed in CICSS. Our model findings implicate CSS as a candidate biomarker of biological aging and frailty.

The role of cardiac pacing therapy in the management of carotid sinus syndrome

Carotid sinus syndrome is characterized by a hypersensitive carotid sinus and syncope. Although we have clear guidelines for the diagnosis and treatment of carotid sinus syndrome, the efficacy of pacing therapy with this indication has not been the subject of many studies. This study aimed to assess the efficacy and safety of pacing therapy in the treatment of patients with carotid sinus syndrome and to determine the factors contributing to symp- toms recurrence after pacemaker implantation. This study was retrospective and included 32 patients in whom a pacemaker was implanted due to carotid sinus syn- drome at the Pacemaker Center, Clinical Center of Serbia, be- tween April 2005 and April 2012. Carotid sinus massage and head-up tilt test (HUTT) were performed to select patients with cardioinhibitory and mixed type carotid sinus syndrome, who were enrolled to the study. The mean age of patients was 65.6 ± 11.5 years and 20 (62.5%) were men. The mean follow-up period was 4.3 ± 1.9 years. HUTT was performed in 3 (9.4%) patients. Twenty-seven (84.4%) patients presented with cardioinhibitory and 5 (15.6%) with mixed type of carotid sinus syndrome. After pacemaker implantation, 22 (68.7%) patients had no further symptoms, 8 (25.0%) had syncope and 2 (6.3%) presyncope.The mixed type of the disease (HR 3.1; 95% CI 1.4-5.1; p = 0.021) and implanta- tion of pacemaker in WI mode (HR 1.8; 95% CI 1.1-3.2; p = 0.034) were independent predictors of symptoms recurrence. There were 3 (9.4%) perioperative surgical complications. Pacemaker therapy is an effective and safe treat- ment for patients with carotid sinus syndrome. As predictors of symptoms persistence after pacemaker implantation in our population, we identified the implantation of pacemaker in WI mode and the mixed type of carotid sinus syndrome.

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.

The role of cardiac pacing in carotid sinus syndrome: a meta-analysis

Cardiac pacing can be used to treat carotid sinus syndrome (CSS), but clinical studies have shown conflicting results. We conducted a systematic review and meta-analysis to evaluate the role of pacing for CSS. A systematic search of publications in PubMed, Embase, and the Cochrane Library without language restriction was performed. Prospective randomized studies that compared cardiac pacing with standard therapy or pacing with different algorithms were included if the recurrence of syncope or the number of falls was observed. Eight studies enrolling 540 patients were identified. In open-label studies, the recurrence of syncope was reduced significantly by cardiac pacing compared with standard therapy. The recurrence of syncope was not different between single- and dual-chamber pacing, but a lower rate of patients with pre-syncope was observed in the group with dual-chamber pacing. Double-blind clinical studies failed to observe the role of cardiac pacing for preventing falls in patients with CSS. The results of meta-analysis supported the use of cardiac pacing for patients with dominant cardioinhibitory CSS.

Treatment of Reflex Syncope

This review assesses the role of all types of therapy for reflex syncope including physical counter-measures, diet, behavior, drugs and implantable devices. There are no drugs currently demonstrated to have convincingly beneficial effect by randomized controlled trial. However, provided that the patient experiences warning of an impending attack physical counter-measures are demonstrably effective. Implantable cardiac pacemakers have a role in a carefully selected minority of patients with vasovagal syncope. Pacing, dual chamber of cardio-inhibitory Carotid Sinus Syndrome is the treatment of choice. Modification of lifestyle in terms of fluid, caffeine and salt consumption is necessary in many cases but has little scientific background. Educating and reassuring the patient is an important part of management. The patient must understand that attacks are not as dangerous as they might seem in most cases and learning to anticipate those permits evasive measures.

The role of pacemaker in hypersensitive carotid sinus syndrome

About 15% of patients with the hypersensitive carotid sinus syndrome (CSS) have no clinical improvement after permanent pacemaker implantation. We aimed to assess the outcome of patients with CSS treated with pacemaker and to determine predictors of symptoms' recurrence. A retrospective analysis of 138 patients in whom pacemaker was implanted for CSS was carried out from February 1990 to October 2008. Data were collected from clinical records. Mean age was 69 ± 10.7 years and 104 patients (75.4%) were men. Mean follow-up period was 4.9 ± 4.4 years. Twenty-one (15.2%) patients presented mixed CSS and 117 (84.8%) cardioinhibitory CSS. The head-up tilt test (HUTT) was performed in 93 patients (67.4%). After pacemaker implantation, 115 (83.3%) patients had no further symptoms, 8 (5.8%) presented minor symptoms and in 15 (10.9%), the symptoms remained unchanged. Among patients with symptoms' recurrence, 8 (38.1%) had mixed CSS and 15 (12.8%) cardioinhibitory CSS. Mixed CSS was the only independent predictor of symptoms' recurrence in total population {hazard ratio (HR) 2.84 [95% confidence intervals (CI) 1.20-6.71]; P = 0.017} and in patients who performed HUTT [HR 1.84 (95% CI 1.01-3.35); P = 0.045]. Although the HUTT result was not related to symptoms' recurrence, patients with mixed CSS were more likely to present a vasodepressor response (61.9 vs. 19.4%; P < 0.001) and a reproduction of spontaneous symptoms (28.6 vs. 2.8%; P = 0,001) on HUTT. Permanent pacemaker is an effective treatment for CSS. However, the recurrence of symptoms was two- to three-fold more frequent in patients with mixed CSS, probably due to the persistence of vasodepressor component.

The intravenous adenosine test: a new test for the identification of bradycardia pacing indications? A pilot study in subjects with bradycardia pacing indications, vasovagal syncope and controls

Intravenous adenosine has recently been used in the diagnosis of unexplained syncope, but there is no consensus as to the meaning of a 'positive' test. The objective is to determine the sensitivity and specificity of intravenous adenosine testing in the diagnosis of bradycardia-pacing indications [sinus node dysfunction(SND), atrio-ventricular block (AVB) and cardio-inhibitory carotid sinus syndrome (CSS)]. Pilot cohort study. Patients-(i) Bradycardia-pacing group: Consecutive patients referred for pacing for SND, AVB and CSS; (ii) Consecutive head-up tilt (HUT)-positive VVS patients. Controls-(i) Simple controls (S-Con: normal examination/ECG) and (ii) Electrophysiology controls (EP-Con: consecutive subjects referred for accessory pathway ablation). Pacing referrals and EP-Con had electrophysiology studies to confirm referral diagnosis and exclude others. All subjects had bolus injection of 20 mg intravenous adenosine during continuous ECG and blood pressure monitoring (positive test: >or=6 s asystole, >or=10 s high-degree AVB post-injection). Sensitivity, specificity, safety and tolerability of the test were measured. Of 264 potential participants (4 SND, 8 AVB, 7 CSS, 10 VVS, 10 EP-Con and 11 S-Con) 50 were studied. All (100%) of the bradycardia-pacing group were adenosine test-positive, as were 6 (60%) VVS. None (0%) and 3 (27%) of the EP- and S-Con groups were positive. Adenosine testing was 100% sensitive and 86% specific for bradycardia-pacing indications, and 100% specific using the diagnostically 'clean' EP-Con results. There were no significant adverse or side effects. Adenosine testing reliably identified patients with definitive bradycardia-pacing indications in whom alternative diagnoses were excluded. Further work is needed to evaluate the role of this test in the diagnosis of unexplained syncope.

Less syncope and milder symptoms in patients treated with pacing for induced cardioinhibitory carotid sinus syndrome: a randomized study

The aim of this study was to examine the effect on symptoms in patients with induced cardioinhibitory carotid sinus syndrome (ICSS) when treated or not treated with a pacemaker. Sixty patients with a history of syncope or pre-syncope and ICSS were randomized to receive a permanent pacemaker (P group, n = 30) or no pacing (NP group, n = 30). ICSS was defined as a ventricular pause (i.e. asystole) lasting 3 s or more in response to carotid sinus stimulation. The patients were seen at 3 and 12 months and at symptoms. At 12 months, the rate of syncope in the NP group was 40% (n = 12) compared with 10% (n = 3) in the P group (P = 0.008). The majority (11 of 12) of the syncope recurrences in the NP group occurred during the first 3 months. Pre-syncope occurred in two patients (7%) in the NP group and in eight (27%) in the P group. Ten patients (33%) with recurrent syncope in the NP group later crossed-over to receive pacemaker implant. A history of syncope or pre-syncope, plus ICSS, was a strong predictor of subsequent syncope or pre-syncope. Most of the new symptoms occurred within 3 months. Pacemaker treatment effectively reduced syncope and/or resulted in milder symptoms.

Atrial fibrillation precipitated by carotid sinus massage in a patient with unexplained syncope

Carotid sinus massage (CSM) is a useful tool in the investigation of unexplained syncope, but is associated with risks. To describe the first reported case of atrial fibrillation precipitated by CSM during the investigation of a patient with recurrent unexplained syncope. A 58-year-old female underwent CSM as part of a tilt test protocol for the investigation of recurrent unexplained syncope. Left CSM revealed the diagnosis of mixed cardioinhibitory and vasodepressor carotid sinus syndrome but also precipitated atrial fibrillation, an arrhythmia previously unreported as a complication of the procedure. CSM is a useful tool in the investigation of patients with recurrent unexplained syncope, but may cause atrial fibrillation in addition to other previously described complications and should, therefore, be used with caution.

Circadian and orthostatic blood pressure is abnormal in the carotid sinus syndrome.

The authors' objective was to determine circadian blood pressure behavior and the prevalence of orthostatic hypotension in patients with cardioinhibitory carotid sinus syndrome. A prospective consecutive series of 160 patients (mean age, 72 [65-83]) with recurrent syncope attributed to cardioinhibitory carotid sinus syndrome was recruited. Mean maximal slowing of heart rate was 4.5 seconds (3.0-5.5 seconds) during carotid sinus massage. Patients had cardiovascular assessments, including 24-hour ambulatory blood pressure measurements (recordings every half-hour during daytime, hourly at night) and morning orthostatic blood pressures before pacemaker implants. Ambulatory measurements were compared with those of 98 age- and sex-matched controls. Nocturnal systolic blood pressure (130.0+/-21.0 vs. 122.1+/-16.7 mm Hg; p<0.005), diastolic blood pressure (72.8+/-12.5 vs. 68.7+/-9.7 mm Hg; p<0.005), and heart rate (66.5+/-9.4 vs. 65.2+/-9.7 bpm; p<0.005), were significantly higher in patients and independent of cardiovascular medication, cardiovascular diagnoses, and orthostatic hypotension. Almost one half of carotid sinus syndrome patients also had orthostatic hypotension. Blood pressure behavior is abnormal in patients with carotid sinus syndrome as represented by altered nocturnal blood pressures and high prevalence of orthostatic hypotension.

Randomized clinical trials of neurally mediated syncope.

Evidence for therapy of neurally mediated syncope is generally weak. Many drugs have been used for the treatment of vasovagal syncope (beta-blockers, disopyramide, scopolamine, clonidine, theophylline, fludrocortisone, ephedrine, dihydroergotamine, etilefrine, midodrine, clonidine, serotonin reuptake inhibitors, enalapril). In general, although the results have been satisfactory in uncontrolled trials or short-term controlled trials, the majority of long-term placebo-controlled prospective trials have not been able to show a benefit of the active drug over placebo. Only two well-designed double-blind placebo-controlled randomized trials have been performed-one for etilefrine and the other for atenolol-and both were unable to show a superiority of the active drug versus placebo. Four randomized clinical trials of pacing therapy-three positive and one negative-have been performed in patients affected by vasovagal syncope. The relationship between carotid sinus hypersensitivity and spontaneous, otherwise unexplained, syncope has been demonstrated. Cardiac pacing appears to be beneficial in carotid sinus syndrome; its efficacy has been demonstrated by two randomized controlled trials and confirmed by several pre-post comparative studies, one controlled trial, and one prospective observational study. There is evidence and general agreement that cardiac pacing is useful in patients with cardioinhibitory or mixed carotid sinus syndrome. Usefulness of the treatment is less well established and divergence of opinion exists with regard to cardiac pacing in patients with cardioinhibitory vasovagal syncope. The evidence fails to support the efficacy of beta-blocking drugs. As yet there are insufficient data to support the use of any other pharmacologic therapy for vasovagal syncope.

Diagnostic yield and development of a neurocardiovascular investigation unit for older adults in a district hospital.

Dizziness, syncope, and falls are common occurrences in elderly people. Neurocardiovascular investigation units aim to detect those patients who fall due to disturbances of blood pressure control or cardiac conduction. Specialist units have a high diagnostic yield in the investigation of these problems. Does this translate to less specialized centers? We report on the diagnostic findings of a district general hospital neurocardiovascular investigation unit. A total of 120 consecutive patients over the age of 65 presenting to a single geriatrician were assessed. After a full history and physical examination, patients underwent neurocardiovascular investigation: blood pressure and heart rate response to active stand, carotid sinus massage, and 30-minute head-up tilt. The 120 patients assessed had a mean age of 78 years (range 66-94 years); in this group, 85 were women. Of these patients, 23% presented with falls, 14% with blackouts, and 30% with dizziness. The remaining 33% had overlap of symptoms. Neurocardiovascular investigations produced a diagnosis in 57% of the patients: 22% had cardioinhibitory carotid sinus syndrome (CSS): 15% had vasodepressor CSS; 29% had orthostatic hypotension; and 3% had vasovagal syncope. Thirteen percent had more than one neurocardiovascular abnormality, and 18% had benign positional vertigo. Five patients had postural instability causing falls. Hyperventilation syndrome, aortic stenosis, dysrhythmia, cervical spondylosis, and epilepsy each accounted for one case. Seventeen percent of the subjects remained undiagnosed after integrated neurocardiovascular assessment. Management of falls requires access to neurocardiovascular assessment. It is feasible to provide such a service in the district general hospital setting, with a comparable diagnostic yield to tertiary referral centers.