Swallow syncope associated with complete atrioventricular block and vasovagal syncope

A 21 year old man presented with multiple, recurrent episodes of complete atrioventricular (AV) block associated with swallowing. Electrophysiological study revealed an AV block with swallowing of carbonated beverages and balloon inflation in the lower oesophagus. Evaluation did not demonstrate any underlying oesophageal or cardiac disease, and the AV block was not induced after intravenous atropine administration. The AV block was probably caused by a hypersensitive vagotonic reflex triggered by mechanical receptors in the lower oesophagus, resulting in suppression of the AV node. Head up tilt test revealed an increase in the high frequency spectrum of heart rate variability before the onset of the syncope. These findings suggest that the amplitude of the continual fluctuations in response to a variety of stimuli and derangement from both intrinsic and extrinsic environments was greater in this patient than in normal subjects. Swallow syncope is an unusual but treatable disorder. These reflexes that become exaggerated to the point of causing illness are poorly understood.


Keywords: swallow syncope; AV block; electrophysiological study; head up tilt test     

Syncope upon swallowing caused by an esophageal hiatal hernia compressing the left atrium: a case report

We describe a patient with syncope associated with swallowing. This syncope was caused by transient compression of the left atrium (LA) by an esophageal hiatal hernia. Two-dimensional echocardiography demonstrated a hyperechoic mass compressing the LA from the posterior. With air insufflation of the esophagus, compression of the LA by this hernia sac was seen to increase. Pulsed and color Doppler echocardiography revealed greatly decreased velocity of blood flowing into the LA and left ventricle (LV). Thus, marked compression of the LA by an esophageal hiatal hernia can cause syncope by impeding blood flow from the LA to the LV. Echocardiography proved highly useful in diagnosis.     

Swallowing syncope: observations in the absence of conduction system or esophageal disease

A patient is described with the clinical syndrome of "swallowing syncope" who reproducibly demonstrated sinus bradycardia, A-H prolongation, and intranodal atrioventricular block in response to swallowing during electrophysiologic study. Baseline electrophysiologic and esophageal manometric results were normal, as was his response to other vagal maneuvers. Demand ventricular pacing alleviated his symptoms. These findings suggest that "swallowing syncope" is mediated via an esophageocardiac reflex and can occur in the absence of cardiac conduction system or esophageal disease.     

Swallowing syncope in a patient with diffuse esophageal spasm]

We present a patient with swallowing syncope. The esophageal manometric examination showed a diffuse spasm. This induces a vagovagal reflex mediated by tensoreceptors from the esophageal wall, which block the AV and/or sinus nodes.     

Swallowing syncope: complex mechanisms of the reflex

A 69-year-old woman was admitted to our hospital for the examination of syncope. When she ate solid food, she had dizziness or loss of consciousness. The ambulatory ECG suggested sino-atrial block during swallowing with a maximum sinus pause of 6 seconds. An electrophysiologic study revealed pre-existing sinus node dysfunction, which was exaggerated by the balloon inflation in the esophagus. Atropine counteracted the slowing of the basal sinus rate induced by esophageal pressure, but it did not block the effect on the maximum sinus node recovery time. This observation suggested that the syncope was mediated partly by a non-vagal mechanism.     

Exercise induced complete atrioventricular block: Utility of exercise stress test

Exercise induced complete atrioventricular block (EIAVB) is a relatively uncommon condition. This phenomenon is clinically important because it can mimic symptoms of other cardiovascular conditions and may be associated with exercise intolerance and subsequent syncope. A 76 year old man with long-standing hypertension and diabetes mellitus presented with recurrent episodes of lightheadedness and syncope with physical activity. ECG showed sinus rhythm with first degree atrioventricular block. Echocardiography did not show any valvular disease causing his symptoms. Coronoary angiographic evaluation revealed non-obstructive coronary artery disease. Because of the exertional nature of his symptoms, a symptom-limited treadmill exercise test was performed which revealed EIAVB. A permanent dual chamber pacemaker was implanted and his symptoms resolved completely.     

Gender effect on the clinical measurement of swallowing

BACKGROUND: Swallowing coordination is affected by cortical and subcortical inputs from the central nervous system. Our hypothesis is that the swallowing dynamics may be influenced by gender. AIM: To evaluate the influence of gender on water swallowing dynamics. METHODS: We studied 111 health subjects, 36 men, aged 24-77 years (mean: 46.3 +/- 16.1 years) and 75 women, aged 22-75 years (mean: 39.6 +/- 13.3 years). All volunteers swallowed in triplicate 50 mL of water at 4 degrees C while precisely timed, when we measured the time to swallow all the volume and counted the number of swallows. We calculated the inter-swallow interval: the time to complete the task, in seconds, divided by the number of swallows; swallowing velocity: volume drunk (mL) by the time taken (s); swallowing volume capacity: volume drunk (mL) divided by the number of swallows. RESULTS: Women had a shorter inter-swallow interval, slower swallowing velocity and lower volume capacity than men. CONCLUSION: Gender has an effect on water swallowing dynamics, with women having a lower swallowing velocity and a lower volume capacity in each swallow than men.     

Syncopes and brief spells of feeling faint: value of Holter monitoring?

A retrospective study of Holter monitoring of 250 patients referred for syncope and short spells of dizziness suspected of being cardiac in origin was undertaken to assess the diagnostic value of the investigation. The arrhythmias observed were classified in 3 groups, significant, suspect and physiological with respect to their true or potential severity and to previously reported results of Holter monitoring in healthy subjects. The following arrhythmias were classified as significant: supraventricular tachycardia with a ventricular rate greater than or equal to 200 bpm; sustained ventricular tachycardia (greater than 30 s and greater than or equal to 150 bpm), bradycardia (less than bpm), sinus arrest (waking greater than 2 s sleeping greater than or equal to 6 s), complete AV block with wide QRS complexes and pacemaker dysfunction. The following arrhythmias were classified as suspect: paroxysmal supraventricular tachycardia with a ventricular rate less than 200 bpm, salvos of ventricular tachycardia (120 greater than 150 bpm); R/T phenomenon and doublets (greater than or equal to 50/24 hours), sinus arrest of 2 to 6 seconds during sleep, complete AV block with narrow QRS complexes or second degree Mobitz II block. This classification led to a diagnosis of certitude in 20 patients (5.7%) with significant arrhythmias concomitant with syncope or a minor form in only 5 cases, supraventricular tachycardia (4 cases), ventricular tachycardia (4 cases), AV block (5 cases), sinus arrest (3 cases), pacemaker dysfunction (4 cases); a diagnosis of presumption in 74 patients (21.1%) with suspect arrhythmias in the absence of syncope or minor equivalent.(ABSTRACT TRUNCATED AT 250 WORDS)     

Abnormal His-Purkinje system conduction leading to complete atrioventricular block in patients with hypertrophic cardiomyopathy: a report of 3 cases

This case report describes three hypertrophic cardiomyopathy patients with abnormal His-Purkinje conduction and complete atrioventricular block with attacks of syncope and cardiopulmonary arrest. Although arrhythmias are common in hypertrophic cardiomyopathy, complete atrioventricular block is very rare. Prolonged QRS duration and abnormal His-Purkinje system conduction may result in complete atrioventricular block.     

Histamine,paroxysmal AV block and low adenosine syncope a case report

Histamine is a widespread natural amine, rarely suspected to provoke syncope due to complete atrio-ventricular block. A patient was admitted to the emergency room after an episode of vomiting and syncope following a dinner of mussels, most likely attributable to a histamine food intoxication. Stale mussels are ostensibly known to occasionally encompass high concentrations of histamine. We hereby present, a documented unexpected complete atrioventricular block (AV block) with preserved stable sinus electrical activity during an episode of fainting with vomiting. Pathophysiologically, we hypothesize a possible intense H1 and/or A1 receptor stimulation linked to histamine overload, suggestive of a variant of idiopathic AVB or low adenosine syncope.     

Swallowing: Is It a Carotid Massage Equivalent Causing Syncope in Patients With Neck Masses?

Syncope associated with the act of swallowing (deglutition syncope) and syncope associated with head and neck cancers have been documented independently. We present a case of syncope precipitated by a combination of both these mechanisms. It is important to recognize the coexistence of different hemodynamically significant mechanisms leading to syncope. A 66-year-old male recently diagnosed with head and neck cancer presented with syncope associated with eating. Diagnosis was complicated because of multiple factors in this patient, which individually could have led to syncope. The patient was on beta-blocker therapy, had a neck mass, and the episodes were associated with swallowing. Our hypothesis is that all these etiologies together led to the events but not in their typical mechanisms and raises the possibility that swallowing can be considered a carotid massage equivalent in patients with neck masses not physically extending to the carotid sinus.     

Symmetry and reproducibility of swallowing sounds

Cervical auscultation is being used more frequently in the clinical assessment of dysphagic patients. The present study was designed to assess symmetry and the reproducibility of swallowing sounds detected simultaneously from bilateral cervical sites. Symmetry of the swallowing sounds acquired using our method was verified because no significant differences were found for any parameters in both time and frequency domain analyses between swallowing sounds detected bilaterally. This result supports the use of a unilateral site for the detection of swallowing sounds. The reproducibility of swallowing sounds was assessed by a coefficient of variation. Results of this analysis suggest that one should evaluate the acoustic characteristics of swallowing sounds from repeated swallows rather than from one swallow.     

Coordination of mastication and swallowing

The coordination of mastication, oral transport, and swallowing was examined during intake of solids and liquids in four normal subjects. Videofluorography (VFG) and electromyography (EMG) were recorded simultaneously while subjects consumed barium-impregnated foods. Intramuscular electrodes were inserted in the masseter, suprahyoid, and infrahyoid muscles. Ninety-four swallows were analyzed frame-by-frame for timing of bolus transport, swallowing, and phases of the masticatory gape cycle. Barium entered the pharynx a mean of 1.1 s (range −0.3 to 6.4 s) before swallow onset. This interval varied significantly among foods and was shortest for liquids. A bolus of food reached the valleculae prior to swallow onset in 37% of sequences, but most of the food was in the oral cavity at the onset of swallowing. Nearly all swallows started during the intercuspal (minimum gape) phase of the masticatory cycle. Selected sequences were analyzed further by computer, using an analog-to-digital convertor (for EMG) and frame grabber (for VFG). When subjects chewed solid food, there were loosely linked cycles of jaw and hyoid motion. A preswallow bolus of chewed food was transported from the oral cavity to the oropharynx by protraction (movement forward and upward) of the tongue and hyoid bone. The tongue compressed the food against the palate and squeezed a portion into the pharynx one or more cycles prior to swallowing. This protraction was produced by contraction of the geniohyoid and anterior digastric muscles, and occurred during the intercuspal (minimum gape) and opening phases of the masticatory cycle. The mechanism of preswallow transport was highly similar to the oral phase of swallowing. Alternation of jaw adductor and abductor activity during mastication provided a framework for integration of chewing, transport, and swallowing.     

Complete heart block as a cause of syncope in asymmetric septal hypertrophy

This case report presents a young adult with asymmetric septal hypertrophy (ASH) and syncope. Infranodal complete heart block was demonstrated as his cause for syncope. Therapy consisted of implantation of a A-V sequential pacemaker. Cardiac output determinations and systolic time intervals demonstrated the beneficial effects of properly timed atrial contractions.     

Congenital complete atrioventricular block: Clinical and electrophysiologic predictors of need for pacemaker insertion

Because an initial Adams-Stokes attack in the patient with congenital complete atrioventricular (A-V) block may sometimes prove fatal, there is a need to be able to identify the patient at great risk of having such attacks. Twenty-four children with congenital complete A-V block were followed up for 1 to 19 years to determine the efficacy of current methods of predicting risk for Adams-Stokes syncope and the usefulness of pacemaker therapy in relieving symptoms. The heart rate at rest, configuration of surface electrocardiographic complexes, data obtained during intracardiac electrophysiologic study and response to graded treadmill exercise testing were compared in children with and without syncope. One or more Adams-Stokes episodes were experienced by eight children, one of whom died. Only a persistent heart rate at rest of 50 beats/min or less demonstrated any significant (probability [p] < 0.01) correlation with the incidence of syncope. Intracardiac electrophysiologic study was of little benefit because the site of block did not correlate with syncope. Although the increase in heart rate during treadmill exercise testing showed no correlation with prevalence of syncope or location of block, exercise-induced ventricular ectopic beats may have predictive value in older children and young adults.

Ventricular pacemakers were implanted in 10 children. Each child was asymptomatic over a 1 to 10 year follow-up period. Because extreme bradycardia may contribute to the prevalence of Adams-Stokes attacks in children with congenital complete A-V block, careful evaluation of heart rate at rest may be an effective means of differentiating patients at risk of syncope. Pacemaker therapy is a feasible and effective method of treatment in young children and relieves symptoms.     

Demonstration of a His-Purkinje Fatigue Phenomenon with Programmed Stimulation of the Right Ventricular Outflow Tract

This report describes the development of atrioventricular block by programmed stimulation of the right ventricular (RV) outflow tract in a patient with undiagnosed syncope. Burst pacing from the RV apex and outflow tract and programmed stimulation from the RV apex were unsuccessful. The observations were consistent with the fatigue phenomenon of the His-Purkinje system and illustrate the importance of an appropriate stimulation protocol in the electrophysiological evaluation of syncope.     

The videoendoscopic swallowing study: An alternative and partner to the videofluoroscopic swallowing study

A new, physical examination-based videoendoscopic method of evaluation can enhance considerably the understanding and efficiency of clinicians working with patients with swallowing difficulties. Using the fiberoptic nasolaryngoscope, evaluation of structure and function of palate, pharynx, and larynx, along with sensation of the laryngopharynx, is carried out. Next, patients' swallowing capabilities are assessed as they ingest various food consistencies. This method, formerly called videoendoscopic evaluation of dysphagia (VEED), but perhaps more appropriately termed videoendoscopic swallowing study (VESS) has particular value for patients who cannot undergo the videofluoroscopic swallowing study (VFSS)—for example, because they are bedfast-or those whose swallowing function is changing so rapidly (after a stroke or surgery) as to call for frequent reassessments. This technique is often useful during the initial consultation with new patients complaining of dysphagia, as a stand alone method of diagnosis and management. Less frequently, VESS findings, along with patient history, will indicate when VFSS should also be obtained. VESS will orient the examiner to the nature and severity of the problem even in this latter circumstance. In follow-up circumstances, VESS is generally more useful than the VFSS. Case presentations are utilized to illustrate the usefulness of VESS as compared to VFSS.     

卒中后吞咽障碍荧光透视与临床吞咽功能的相关性

目的探讨吞咽障碍患者的临床表现与吞咽荧光透视检查(VFSS)所示结构和功能的相关性。方法连续收集2012年6月—2014年5月浙江中医药大学附属温州市中医院收治的56例卒中后吞咽障碍患者,选择性应用4种不同质地的食物进行测试,分别完成临床吞咽功能评估和VFSS检查,并用SPSS 20.0统计软件对该两种方法的各项观察指标进行单因素分析和多因素Logistic回归分析。结果临床表现与VFSS检查的点对应关系在口腔期有口内食物残留与口唇闭合异常(95%CI:1.430~101.468,P=0.022);软腭上抬差与口腔食物残留(95%CI:1.476~102.033,P=0.020);分次吞咽与口通过时间延长(95%CI:2.616~182.897,P=0.004);舌运动障碍及软腭上抬差与食团形成障碍(95%CI分别为1.468~50.795、1.220~13.825,P值分别为0.017、0.023);食物口角漏出、咽下困难与食团从舌根掉落会厌或气管(95%CI分别为1.146~125.459、1.657~174.400,P值分别为0.038、0.017)。在咽期主要有咽反射减弱与喉上抬程度弱(95%CI:1.150~92.815,P=0.037);咽下困难、吞咽延迟与吞咽反射启动触发时间长(95%CI分别为2.123~37.770、1.233~114.176,P值分别为0.003、0.032);分次吞咽、用力吞咽、哽噎感以及喉上抬差与咽期通过时间长(95%CI分别为1.619~223.316、1.061~31.445、2.834~132.707,P值分别为0.019、0.042、0.003);咽下困难与环咽肌开放不全(95%CI:1.037~24.115,P=0.045);喉上抬程度弱、咽部异物感、吞咽后呛咳与会厌谷或梨状窝滞留或残留(95%CI分别为1.046~13.685、1.116~87.741,P值分别为0.043、0.040);吞咽过程中咳嗽、进食呛咳与误吸(95%CI分别为0.010~0.921、0.037~0.826,P值分别为0.042、0.028)等,均存在明显相关性。结论某些临床症状表现与VFSS检查发现的吞咽功能异常密切相关,借助该规律可更简捷、安全地判断患者吞咽障碍程度及类型,为不能接受VFSS检查的卒中后吞咽障碍患者进行康复治疗作指导。     

Complete heart block in an Inuit family

An Inuit family from Cape Dorset, Northwest Territories is described; six had documented complete heart block, one high grade atrioventricular block, one bi- or trifascicular block and all suffered syncope. One other member received a pacemaker for unknown reasons. Two of three middle-aged relatives had minor conduction abnormalities. All younger family members who were examined had no conduction problems. This suggests a heritable form of adult onset complete heart block, the largest series reported in the English literature.