Cardioinhibitory Carotid Sinus Hypersensitivity Research Articles

Long-Term Mortality in Cardioinhibitory Carotid Sinus Hypersensitivity Patient Cohort.

BackgroundCardioinhibitory carotid sinus hypersensitivity (CICSH) is defined as ventricular asystole ≥ 3 seconds in response to 5-10 seconds of carotid sinus massage (CSM). There is a common concern that a prolonged asystole episode could lead to death directly from bradycardia or as a consequence of serious trauma, brain injury or pause-dependent ventricular arrhythmias.ObjectiveTo describe total mortality, cardiovascular mortality and trauma-related mortality of a cohort of CICSH patients, and to compare those mortalities with those found in a non-CICSH patient cohort.MethodsIn 2006, 502 patients ≥ 50 years of age were submitted to CSM. Fifty-two patients (10,4%) were identified with CICSH. Survival of this cohort was compared with that of another cohort of 408 non-CICSH patients using Kaplan-Meier curves. Cox regression was used to examine the relation between CICSH and mortality. The level of statistical significance was set at 0.05.ResultsAfter a maximum follow-up of 11.6 years, 29 of the 52 CICSH patients (55.8%) were dead. Cardiovascular mortality, trauma-related mortality and the total mortality rate of this population were not statistically different from that found in 408 patients without CICSH. (Total mortality of CICSH patients 55.8% vs. 49,3% of non-CICSH patients; p: 0.38).ConclusionAt the end of follow-up, the 52 CICSH patient cohort had total mortality, cardiovascular mortality and trauma-related mortality similar to that found in 408 patients without CICSH.

Prevention of falls in old people – a review

SummaryPhysical training, if including specific different training modalities, reduces the fall risk in healthy community-dwelling older people, as does a home hazards modification programme. Vitamin D supplementation in older individuals with low levels of vitamin D, adjustment of psychotropic medication, and structured modification of multi-pharmacy are all drug-focused programmes that reduce the number of falls. Anti-slip shoe devices during icy conditions for older people who walk outdoors and multifaceted podiatry in patients with specific foot disability reduce the fall risk. First eye cataract surgery and pacemakers in patients with cardio-inhibitory carotid sinus hypersensitivity are surgical interventions that reduce the fall risk. Multi-factorial preventive programmes that include training, both individually designed and generally prescribed, also reduce the fall frequency. With this in mind, we ought to initiate fall preventive programmes in older people, especially in high- risk groups, to reduce the number of falls and fallers in society.

Prevention of falls in the elderly: A review

Falls often result in soft tissue injuries, dislocations, fractures, longstanding pain and reduced quality of life. Therefore, fall preventive programmes have been developed. In this review, we evaluate programmes that in randomized controlled trials (RCT) have been shown with fall reducing effect. Physical exercise that includes several training modalities, especially balance and strength training, is the only intervention programme that reduces both the number of fallers and the number of falls in community dwellers. Home hazards modification reduces the fall risk in community-living elderly but has the best effects in high risk groups when the programme is led by occupational therapists. Vitamin D supplement in those with low levels of vitamin D, adjustment of psychotropic medication and modification of multi-pharmacy are drug-related programmes that reduce the fall risk. Anti-slip shoe devices in elderly who walk outdoors during icy conditions and multifaceted podiatry to patients with specific foot disability are interventions targeted at the lower extremities with a fall-reducing effect. First eye cataract surgery and pacemakers in patients with cardio-inhibitory carotid sinus hypersensitivity are surgical procedures with fall-reducing effect. Multifactorial standardized preventive programmes that include an exercise component and individually-designed subject-specific programmes also reduce the number of falls. Fall preventive interventions should be provided to elderly by a structured approach, especially to high risk groups, as to reduce the number of falls and fallers.

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.

Prevention of falls in the elderly—a review

The proportion of elderly in the society increases and fall frequency increases with advancing age. Many falls result in fractures and also soft tissue injuries, longstanding pain, functional impairment, reduced quality of life, increased mortality, and excess in healthcare costs. Due to the magnitude of these negative effects, a variety of single- and multicomponent fall-preventive intervention programs has been initiated.This review identifies programs that, in randomized controlled trials (RCTs), have been shown with fall-reductive effects.The most effective strategies in community-dwelling elderly include regular physical training with program that includes several different training modalities. Modification of the overall or patient-specific risk factor profile in home hazard modification program has been proven to decrease fall risk in community-living elderly. The elderly in the community benefit also from wearing antislip shoe devices when walking in icy conditions, from adjustment of psychotropic medication, and from structured modification of multipharmacy. If vitamin D levels in blood are low, supplementation is beneficial as is the first eye cataract surgery and pacemaker implantation in patients with cardioinhibitory carotid sinus hypersensitivity. In addition to modification of specific risk factors, generalized and individualized multifactorial preventive programs, all including some sort of physical training, have been found to decrease the fall risk. In summary, there is now strong evidence in the literature that structured fall-preventive programs in the elderly, especially in high-risk groups, are beneficial in reducing both the number of fallers and the number of falls in community.

Evaluation of Sinus and Atrioventricular Nodes Function in Patients with Vasovagal Syncope

Evaluation of sinus and atrioventricular nodes function as a potential factor responsible for prolonged bradycardia, asystole, or both in patients with cardioinhibitory and non-cardioinhibitory vasovagal syncope (VVS). The study included 258 patients (mean age = 47.7 +/- 17.2 years; range 18-62; 147 females) with a history of VVS. They were divided among four groups, according to results of head-up tilt test (HUTT). All patients underwent standard HUTT, carotid sinus massage (CSM), and rapid transesophageal atrial pacing for evaluation of total sinus node recovery time (SNRT), and corrected sinus node recovery time (CNRT), resting and intrinsic heart rate (IHR), and Wenckebach point (WP). Values of SNRT > 1,500 ms, CNRT > 525 ms, WP < 130 bpm, and CSM-induced pause >3 seconds were considered abnormal. SNRT, CNRT, and WP before and after pharmacological blockade, resting heart rate, and IHR did not differ significantly among the study groups. The prevalence of mild sinus node dysfunction (SND), decreased value of WP, and cardioinhibitory carotid sinus hypersensitivity was similar among all study groups. The prevalence of mild SND, abnormal atrioventricular conduction, and carotid sinus hypersensitivity (CSH) was similar among patients with VVS regardless of the type of vasovagal reaction. SND and CSH do not seem to play an important role in the pathogenesis of cardioinhibitory vasovagal reaction.

Cardioinhibitory carotid sinus hypersensitivity predicts an asystolic mechanism of spontaneous neurally mediated syncope

We correlated the finding of cardioinhibitory carotid sinus hypersensitivity (CSH) with that observed during a spontaneous syncopal relapse by means of an implantable loop recorder (ILR). We included 18 consecutive patients with suspected recurrent neurally mediated syncope and positive cardioinhibitory response during carotid sinus massage (max pause 5.5 +/- 1.6 s) who had subsequent documentation of a spontaneous syncope by means of an ILR. They were compared with a 2:1 age- and sex-matched group of 36 patients with a clinical diagnosis of recurrent neurally mediated syncope and negative response to carotid sinus massage, tilt testing and ATP test. Asystole >3 s was observed at the time of the spontaneous syncope in 16 (89%) of CSH patients and in 18 (50%) of the control group (P = 0.007). Sinus arrest was the most frequent finding among CSH patients but not among controls (72 vs. 28%, P = 0.003). After ILR documentation, 14 CSH patients with asystole received dual-chamber pacemaker implantation; during 35 +/- 22 months of follow-up, 2 syncopal episodes recurred in 2 patients (14%), and pre-syncope occurred in another 2 patients (14%). Syncope burden decreased from 1.68 (95% confidence interval 1.66 - 1.70) episodes per patient per year before to 0.04 (0.038-0.042) after pacemaker implant (98% relative risk reduction). In patients with suspected neurally mediated syncope, the finding of cardioinhibitory CSH predicts an asystolic mechanism at the time of spontaneous syncope and, consequently, suggests a possible benefit of cardiac pacing therapy.

The prevalence of falls in older persons paced for atrioventricular block and sick sinus syndrome.

Falls are a major health priority. Eight percent of persons over age 70 present to emergency departments each year due to a fall; fall-related injuries account for 6% of all medical expenditures for persons age 65 and older in the United States. Pacing reduces falls by 70% in patients with cardioinhibitory carotid sinus hypersensitivity. The prevalence of falls in other bradyarrhythmic disorders is not known. The purpose of the following study was to compare the prevalence of falls in older adults with atrioventricular block and sick sinus syndrome with case controls. Consecutive subjects who had pacemakers implanted for atrioventricular block and sick sinus syndrome were assessed. Age and gender-matched admissions to the coronary care unit were similarly studied. Eighty-one subjects were included in the study, 31 paced and 50 controls. There were 134 falls in the bradyarrhythmic group and 12 in the control group. The authors conclude that this is the first series that clearly shows a significant association between atrioventricular block, sick sinus syndrome, and falls. Further prospective studies are needed to substantiate these results.

Neurocardiovascular instability in cognitive impairment and dementia.

Neurocardiovascular instability (NCVI, neurally mediated disorders causing hypotension with or without bradycardia) represents abnormal neural control of the cardiovascular system and presents as dizziness, syncope, or falls. The mechanisms underpinning NCVI are incompletely understood. The three most common disorders are carotid sinus syndrome (CSS), orthostatic hypotension (OH), and vasovagal syndrome (VVS): CSS, cardioinhibition > 3 s and/or vasodepressor response > or = 50 mmHg drop in systolic pressure during carotid sinus stimulation; OH: fall in systolic blood pressure > 20 mmHg during standing; VVS: cardioinhibition > 3 s and/or vasodepressor response > 50 mmHg during prolonged head-up tilting. In fallers with cognitive impairment or dementia, the prevalence of NCVI is 70%. Multifactorial interventions, including treatment of NCVI, significantly reduce falls and syncope. The predominant components of NCVI in fallers with cognitive impairment and dementia are CSS and OH. In Lewy body and Alzheimer's dementia, the prevalence of NCVI is up to 60%, again predominantly CSS and OH. The prevalence of cardioinhibitory carotid sinus hypersensitivity is particularly high in Lewy body dementia-41% compared with 12% in Alzheimer's disease and 3% in case controls. In addition, patients with Lewy body dementia have greater heart rate slowing (>2 s) and falls in systolic blood pressure (>20 mmHg) than those with Alzheimer's disease or controls during carotid sinus stimulation. The extent of deep white matter hyperintensities on MRI correlates with systolic fall during carotid sinus stimulation (R = 0.58; p < 0.005), suggesting a possible causal association between bradyarrhythmia-induced hypotension and microvascular pathology. NCVI is common in patients with dementia and may be a reversible cause of falls and syncope. Repeated hypotensive episodes may exaggerate cognitive decline in these patients.

Cardiac pacing reduced nonaccidental falls in older adults with cardioinhibitory carotid sinus hypersensitivity

Cardiac pacing reduced nonaccidental falls in older adults with cardioinhibitory carotid sinus hypersensitivity

Cardiac pacing reduced non-accidental falls in older adults with cardioinhibitory carotid sinus hypersensitivity

(2001) J Am Coll Cardiol 38, 1491; Kenny RA, Richardson DA, Steen N, et al. . Carotid sinus syndrome: a modifiable risk factor for nonaccidental falls in older adults (SAFE...

Carotid sinus syndrome: a modifiable risk factor for nonaccidental falls in older adults (SAFE PACE)

OBJECTIVESThe aim of the study was to determine whether cardiac pacing reduces falls in older adults with cardioinhibitory carotid sinus hypersensitivity (CSH).BACKGROUNDCardioinhibitory carotid sinus syndrome causes syncope, and symptoms respond to cardiac pacing. There is circumstantial evidence for an association between falls and the syndrome.METHODSA randomized controlled trial was done of consecutive older patients (>50 years) attending an accident and emergency facility because of a non-accidental fall. Patients were randomized to dual-chamber pacemaker implant (paced patients) or standard treatment (controls). The primary outcome was the number of falls during one year of follow-up.RESULTSOne hundred seventy-five eligible patients (mean age 73 ± 10 years; 60% women) were randomized to the trial: pacemaker 87; controls 88. Falls (without loss of consciousness) were reduced by two-thirds: controls reported 669 falls (mean 9.3; range 0 to 89), and paced patients 216 falls (mean 4.1; range 0 to 29). Thus, paced patients were significantly less likely to fall (odds ratio 0.42; 95% confidence interval: 0.23, 0.75) than were controls. Syncopal events were also reduced during the follow-up period, but there were much fewer syncopal events than falls—28 episodes in paced patients and 47 in controls. Injurious events were reduced by 70% (202 in controls compared to 61 in paced patients).CONCLUSIONSThere is a strong association between non-accidental falls and cardioinhibitory CSH. These patients would not usually be referred for cardiovascular assessment. Carotid sinus hypersensitivity should be considered in all older adults who have non-accidental falls.

Effect of recent randomized trials on current pacing practice.

The most common indication for a permanent pacemaker is symptomatic bradycardia. An atrial-based pacemaker (dual-chamber or atrial) usually is preferred, except in patients with chronic atrial fibrillation. Several prospective, randomized trials recently have been completed to evaluate new indications for permanent pacemakers. A dual-chamber pacemaker with an optimal atrioventricular interval can reduce the left ventricular outflow tract gradient by >50% in patients with hypertrophic cardiomyopathy. This has been associated with symptomatic improvement in the majority of patients, but an important placebo effect appears likely. Pacing also has been evaluated in patients with medically refractory dilated cardiomyopathy. Despite encouraging initial studies, routine implantation of a permanent pacemaker in dilated cardiomyopathy is not indicated. In patients with cardioinhibitory or mixed vasovagal syncope and carotid sinus hypersensitivity, implantation of a pacemaker markedly decreases syncopal episodes. Pacemaker therapy is clearly indicated in patients with atrial fibrillation associated with symptomatic bradycardia, and exciting new data on the use of pacing to prevent atrial fibrillation appear promising. The best pacing modality for this indication may be dual-site atrial pacing. Finally, permanent pacemakers play an important role in the treatment of symptomatic long QT syndrome, usually in combination with beta-blockers.

High prevalence of neurovascular instability in neurodegenerative dementias.

Orthostatic hypotension and carotid sinus hypersensitivity were assessed in patients meeting clinical criteria for dementia with Lewy bodies (DLB; n=30) and AD (n=35). Cardioinhibitory carotid sinus hypersensitivity (CI) was the most common sign (AD patients, 28%; DLB patients, 41%). Preliminary data from a secondary analysis excluding patients with hypertension or EKG evidence of ischemia suggested that CI may be significantly more common in DLB. Larger studies are needed to evaluate the implications for treatment and to explore the underlying mechanisms.

Prevalence of cardioinhibitory carotid sinus hypersensitivity in patients 50 years or over presenting to the accident and emergency department with "unexplained" or "recurrent" falls.

To study the prevalence of Cardioinhibitory Carotid Sinus Hypersensitivity (CICSH) in patients 50 years or over presenting to casualty with "unexplained" or "recurrent" falls. The prospective study was from October 1, 1995 to April 30, 1996 in the Inner City Accident and Emergency Departments, Newcastle Upon Tyne, U.K. Ten thousand four hundred forty-three patients 50 years and over presented, of which 4,051 (39%) were fallers. Fallers were excluded if they lived over 15 miles from the hospital (81), were registered blind (17), were unable to speak English (22), were unable to previously walk (27), if there was a history of only one accidental fall (1,659) or were cognitively impaired (776: Mini Mental State Examination < 24 [30]) or if there was a clear attributable medical diagnosis for the fall (871). Five hundred ninety-eight "unexplained" or "recurrent" fallers (defined as three or more falls in the previous 12 months) were assessed for carotid sinus massage (CSM). One hundred forty-five patients declined CSM (24%), 70 (12%) had relative contraindications to CSM and 13 already had pacemakers in situ (2%). Two hundred seventy-nine underwent CSM, of whom 65 had CICSH (23%), which might be amenable to treatment with pacemakers. The prevalence of CICSH (a potentially treatable condition) in "unexplained" or "recurrent" fallers who present to the accident and emergency department is 23%. A randomized control study to assess benefit from pacemaker intervention in these patients is underway.

Pathophysiology of carotid sinus hypersensitivity in elderly patients

Summary Carotid sinus hypersensitivity (CSH) is recognised in up to 45% of elderly patients with syncope, falls, and dizziness that may not be attributed to specific myocardial sinus node dysfunction, various diseases that affect pacemaker activity, cardiac output and blood supply to the brain. The pathophysiology of CSH is unclear but it is associated with ageing, hypertension, and ischaemic heart disease. CSH is potentially treatable with dual chamber pacing for prolonged sinus arrest (cardio-inhibitory CSH) but therapy for the more prevalent hypotension (vasodepressor CSH) is unsatisfactory. However, hypersensitivity of the carotid sinus is not consistent with the known blunting effects of senescence and hypertension on baroreflex sensitivity. The present hypothesis proposes that CSH in elderly patients results from up-regulation of brainstem postsynaptic α-2 adrenoceptors. Reduced carotid sinus compliance in elderly arteriosclerotic hypertensive patients will reduce afferent impulse traffic in the baroreflex pathway. Such relative deafferentation may be expected to cause baroreflex postsynaptic hypersensitivity, mediated by up-regulation of the dominant postsynaptic receptor population in the baroreflex pathway, ie, α-2 adrenoceptors. Vigorous carotid sinus stimulation, eg, massage, could thus cause an overshoot baroreflex efferent response, resulting in profound hypotension and bradycardia. Hypotension and bradycardia are compounded by the effects of age, hypertension, ischaemic heart disease and arteriosclerosis on rapid cardiovascular compensation, resulting in cerebral hypoperfusion and syncope. Thus, CSH in elderly patients should be considered as a clinical marker of widespread arteriosclerotic disease, rather than as a distinct disease entity. If correct, this hypothesis has potentially important implications for the pharmacotherapy of hypotension-related symptoms in elderly arteriosclerotic patients.

Pattern of inhibition of parasympathetic activity in response to incremental bolus doses of atropine in carotid sinus hypersensitivity.

Patients with established reproducible cardioinhibitory carotid sinus hypersensitivity were studied to define the dose of atropine required to abolish the heart rate slowing in response to carotid sinus massage, the heart rate response to the Valsalva manoeuvre and salivary gland flow. Bolus doses of intravenous atropine were given to a cumulative dose of 700 mcg. Cardioinhibition was abolished in all patients with a total dose of 700 mcg. The heart rate ratio during the Valsalva manoeuvre did not vary significantly. The decline in salivary gland flow was evident earliest, at a dose of 75 mcg. In clinical studies, 700 mcg of atropine will abolish the diagnostic cardioinhibitory response to carotid sinus message in patients with the syndrome. This may not prevent syncope, as could occur in the key frequent vasodepressor form of carotid sinus hypersensitivity syndrome.

The carotid sinus syndrome: A frequently overlooked cause of syncope in the elderly

Exaggerated carotid sinus reflexes may account for alterations in consciousness responsible for significant disability and injury in elderly patients. Nonspecificity of symptoms and concomitant medical conditions frequently delay diagnosis and therapy. During a recent 9-year period, 82 patients were identified as having symptomatic carotid sinus hypersensitivity (CSH). Fifty-nine patients described complete syncope, 73 patients had multiple syncopal or near-syncopal episodes, and 40 patients related cervical pressure or motion as provocative events. Electrophysiologic testing demonstrated that 47% had cardioinhibitory CSH, 26% had vasodepressor CSH, and 27% had combined vasodepressor and cardioinhibitory CSH. The mean follow-up period of all patients was 36 months. Surgical therapy included ventricular demand pacemaker implantation in 33 patients and carotid sinus denervation in seven patients. Medical therapy was used in 32 patients, 11 mildly symptomatic patients were not treated, and 3 patients had carotid sinus irradiation. Pacemaker implantation relieved symptoms in 53%; however, 11 patients (33%) had significant postoperative complications. Carotid sinus denervation relieved symptoms in 86%, medical therapy in 54%, and carotid sinus irradiation in 33% of patients. Because of its demonstrated effectiveness in all variants of CSH and negligible perioperative morbidity, carotid sinus denervation should be offered to acceptable operative candidates when the diagnosis of CSH is confirmed.

Studies on the differential diagnosis between the primary and secondary cardioinhibitory carotid sinus hypersensitivity.

Studies on the differential diagnosis between the primary and secondary cardioinhibitory carotid sinus hypersensitivity.

Cardioinhibitory carotid sinus hypersensitivity. Intracardiac recordings and clinical assessment

Cardioinhibitory carotid sinus hypersensitivity. Intracardiac recordings and clinical assessment