CAROTID SINUS HYPERSENSITIVITY IN PATIENTS REFERRED WITH POSSIBLE EPILEPSY

SUMMARY Four patients with recurrent transient loss of consciousness, all of whom had previously undergone extensive non-invasive cardiological investigations, were referred for neurological opinion. All were found to exhibit a resting bradycardia and a cardioinhibitory response to carotid sinus stimulation. All were referred for cardiological opinion but only two patients were considered by their respective cardiologists to warrant pacemaker implantation. Those who did not receive a pacemaker continue to suffer from their symptoms. The clinical management of these patients highlights an apparent divergence of opinion amongst cardiologists on the treatment of carotid sinus hypersensitivity and emphasises that, unless the ECG and blood pressure responses to carotid sinus stimulation are observed in patients with histories of unexplained episodes of altered consciousness, carotid sinus hypersensitivity will be missed as a possible cause of symptoms. The presence of unexplained bradycardia may suggest carotid sinus hypersensitivity.     

Cough Syncope Caused by Sinus Arrest in a Patient with Sick Sinus Syndrome

Cough syncope is a syndrome in which dizziness or syncope occurs after prolonged bouts of cough. This paper presents a case of 63-year-old man with recurrent dizziness and syncope. The 24-hour ambulatory electrocardiogram and intracardiac electrogram showed sinus node dysfunction with sinus arrest, both spontaneous and inducible by voluntary cough. Sinus arrest was sometimes associated with dizziness. A permanent VVI pacemaker was implanted and no further cough syncope has occurred. We suggest that sinus arrest may play a role as a mechanism of cough syncope in a patient with sick sinus syndrome.     

Thalidomide-induced sinus bradycardia

OBJECTIVE: To report a case of thalidomide-induced sinus bradycardia in an elderly man. CASE SUMMARY: A 72-year-old white man, with transfusion-dependent refractory anemia with ringed sideroblasts and hypertension treated with atenolol, was started on thalidomide 100 mg at bedtime. During the dose titration period (maximum dose 400 mg/d), his heart rate decreased from a baseline of 63 beats/min to as low as 44 beats/min with positive electrocardiogram findings of sinus bradycardia. After discontinuation of atenolol, the patient's heart rate increased to 68 beats/min, but symptoms of bradycardia persisted. Due to the patient's continued dizziness and lightheadedness, thalidomide was discontinued. In the 3 months following discontinuation of thalidomide, the patient's heart rate increased to an average of 74 beats/min. DISCUSSION: Clinical trials and postmarketing surveillance suggest that the incidence of thalidomide-induced bradycardia is low. The mechanism of this effect is unknown. Concurrent medications affecting the heart rate may also increase the risk of thalidomide-induced bradycardia. Following titration of thalidomide to a maximum dose of 400 mg/d, our patient's heart rate decreased markedly, resulting in intermittent symptoms of lightheadedness and dizziness. He may have been at higher risk of thalidomide-induced bradycardia because of concurrent administration of atenolol. An objective causality assessment revealed that the adverse event was probable. CONCLUSIONS: Despite the low incidence of thalidomide-induced bradycardia, it appears to be an important adverse effect, particularly in patients with comorbidities or concurrent medications that decrease heart rate. Therefore, providers should monitor these patients closely for signs and symptoms of bradycardia during the administration of thalidomide.     

Intermittent Pacemaker Syndrome: Revision of VVI Pacemaker to a New Cardiac Pacing Mode for Tachy-Brady Syndrome

A patient with tachy-brady syndrome manifested by paroxysmal atrial fibrillation and symptomatic sinus bradycardia and treated by VVI pacing developed pacemaker syndrome during episodes of ventricular pacing. His cardiac pacemaker was revised to a dual chamber system utilizing the new AV sequential DDI pacing mode which eliminated pacemaker-related tachycardias and totally abolished the pacemaker syndrome symptoms. There have been no further episodes of atrial fibrillation, possibly due to elimination of temporal dispersion of refractory periods during bradycardia. The propensity for atrial fibrillation has also been minimized by excluding competitive atrial stimulation during DVI pacing. The DDI mode provides the clinician increased utility and flexibility in the use of AV sequential pacing therapy.     

Assessment of VVI Diagnostic Pacing Mode in Patients with Cardioinhibitory Carotid Sinus Syndrome

In this study, we used Holter pacemakers in a group of 13 patients affected by severe carotid sinus syndrome in order to evaluate its evolution. All the patients had one to three syncopal episodes and frequent other symptoms such as fainting, dizziness, lightheadedness and pre-syncope interferring with their daily activity so that pacemaker therapy was considered necessary. Patient selection criteria were: presence of the isolated cardioinhibitory type, absence of associated sinus dysfunction and absence of symptomatic WI pacemaker effect. All the patients received a Micropacer 1 device; among special functions, bradycardia events counter was activated and programmed so that each sequence of three consecutives beats at a cycle length 1.5 sec (i.e., 4.5 sec total interval) could he recognized and stored in its memory. The follow-up lasted 13±7 months. Brady events occurred in eight out of 13 patients (62%), during this period. Syncope and major symptoms disappeared in ail the patients; mild dizziness recurred rarely in two patients and were not linked to brady-events recording. In conclusion, disappearance of severe symptoms observed after pacemaker implant in cardioinhibitory carotid sinus syndrome seems to depend from pacing therapy, in most cases, yet from the benign natural course of the disease in some other cases.     

The Use of Serotonin Reuptake Inhibitors for the Treatment of Recurrent Syncope Due to Carotid Sinus Hypersensitivity Unresponsive to Dual Chamber Cardiac Pacing

Carotid sinus hypersensitivity can be a cause of recurrent unexplained syncope in the older patient. Dual chamber cardiac pacing may relieve the bradycardia, but may not affect the vasodilatory component of this disorder. We report on two patients with carotid sinus hypersensitivity with a predominant vasodilatory component who experienced recurrent syncope following permanent pacemaker implantation. Both patients were treated with serotonin reuptake inhibitors and after 4–6 weeks of therapy had complete resolution of symptoms. We conclude that serotonin reuptake inhibitors may be useful in the treatment of recurrent syncope due to carotid sinus hypersensitivity resistant to dual chamber cardiac pacing.     

Sphenopalatine ganglion block for treatment of sinus arrest in postherpetic neuralgia

A 64-year-old woman presented with bradycardia from sinus pauses during exacerbations of postherpetic trigeminal distribution neuralgia. She had underlying systemic lupus erythematosus. Sphenopalatine ganglion blockade was employed to treat her pain. The episodes of bradycardia resolved with successful alleviation of pain. This report emphasizes that a sphenopalatine ganglion blockade can be employed in the treatment and prevention of sinus arrest associated with postherpetic trigeminal distribution neuralgia.     

Intravenous theophylline--an alternative to temporary pacing in the management of bradycardia secondary to AV nodal block

OBJECTIVE: To report a case of bradycardia secondary to atrioventricular nodal block (AVNB) successfully treated with intravenous theophylline. Intravenous theophylline was used as an alternative to temporary pacing in a patient with sepsis secondary to thermal injury. CASE SUMMARY: A 79-year-old white woman with significant cardiac history was admitted with 14.5% total body surface area burns after a house fire. Cardiac events included intermittent episodes of sinus bradycardia complicated by the development of second-degree AVNB and periods of sinus arrest. Intravenous theophylline initiation maintained normal sinus rhythm without further episodes of sinus bradycardia or heart block, thus preventing the need for cardiac pacemaker placement. DISCUSSION: This is the first case published in the English-language literature describing the use of intravenous theophylline as an alternative therapy to temporary pacing in a patient with sepsis secondary to thermal injury. Bradyarrhythmic events in sepsis patients have been associated with catecholamine production increasing adenosine formation. High concentrations of adenosine in the areas of the sinoatrial or atrioventricular nodal regions may induce sinus bradycardia or AVNB. Theophylline, an adenosine antagonist, has been identified as a treatment option for such bradyarrhythmic events. CONCLUSIONS: Theophylline, a methylxanthine derivative, may represent an alternative to other pharmacologic therapies and temporary pacing in the treatment of bradycardia secondary to AVNB. These agents may represent a pharmacologic alternative in patients in whom other pharmacologic strategies or cardiac pacemaker insertion may be contraindicated.     

Diagnosis and treatment of sick sinus syndrome

Sick sinus syndrome comprises a variety of conditions involving sinus node dysfunction and commonly affects elderly persons. While the syndrome can have many causes, it usually is idiopathic. Patients may experience syncope, pre-syncope, palpitations, or dizziness; however, they often are asymptomatic or have subtle or nonspecific symptoms. Sick sinus syndrome has multiple manifestations on electrocardiogram, including sinus bradycardia, sinus arrest, sinoatrial block, and alternating patterns of bradycardia and tachycardia (bradycardia-tachycardia syndrome). Diagnosis of sick sinus syndrome can be difficult because of its nonspecific symptoms and elusive findings on electrocardiogram or Holter monitor. The mainstay of treatment is atrial or dual-chamber pacemaker placement, which generally provides effective relief of symptoms and lowers the incidence of atrial fibrillation, thromboembolic events, heart failure, and mortality, compared with ventricular pacemakers.     

Arrhythmia diagnosis and management throughout life in congenital heart disease

Arrhythmias, covering bradycardia and tachycardia, occur in association with congenital heart disease (CHD) and as a consequence of surgical repair. Symptomatic bradycardia can occur due to sinus node dysfunction or atrioventricular block secondary to either unrepaired CHD or surgical repair in the area of the conduction system. Tachyarrhythmias are common in repaired CHD due to scar formation, chamber distension or increased chamber pressure, all potentially leading to abnormal automaticity and heterogeneous conduction properties as a substrate for re-entry. Atrial arrhythmias occur more frequently, but ventricular tachyarrhythmias may be associated with an increased risk of sudden cardiac death, notably in patients with repaired tetralogy of Fallot or aortic stenosis. Defibrillator implantation provides life-saving electrical therapy for hemodynamically unstable arrhythmias. Ablation procedures with 3D electroanatomic mapping technology offer a viable alternative to pharmacologic or device therapy. Advances in electrophysiology have allowed for successful management of arrhythmias in patients with congenital heart disease.     

SEVERE BRADYARRHYTHMIA IN A PATIENT WITH ALZHEIMER'S DISEASE AND A PATIENT WITH CEREBRAL ISCHAEMIA,BOTH INDUCED BY ACUTE DISTENSION OF THE BLADDER

Two case reports are presented of bradycardia in two elderly patients, which was resistant to atropine but which resolved immediately the acute bladder distension was treated. Generally, a sympathetic cardiac response is expected, and this paradoxical response may be due not only to lesions of the reflex loop involving both the vagal and the sympathetic nerves, but also to endocrinological factors. As acute urinary distension is not uncommon on geriatric wards, bradyarrhythmia due to bladder distension should be considered in elderly patients.     

Temporary coronary sinus pacing to improve ventricular dyssynchrony with cardiogenic shock: A case report

BACKGROUNDTemporary transvenous pacing through the coronary sinus is a novel approach rarely used in treating unstable bradycardia. This modality could provide cardiac pacing while achieving better ventricular synchrony. We present a case who received cardiac pacing through the coronary sinus and provide a summary of evidence in the current literature.CASE SUMMARYA 55-year-old woman with a history of advanced heart failure was admitted to the rehabilitation ward after a recent stroke. During hospitalization, she had paroxysmal atrial fibrillation with rapid ventricular response resulting from fluid overload. While atrial fibrillation was spontaneously reversed to sinus rhythm after diuresis, she developed multiple episodes of polymorphic ventricular tachycardia along with sinus bradycardia and prolonged QTc interval. She became hypotensive despite appropriate medical management. Pacing through her implantable cardioverter-defibrillator was attempted but worsened her hypotension. Ventricular dyssynchrony was suspected. Temporary transvenous atrial pacing through the coronary sinus was performed, which stabilized her blood pressure and improved end-organ perfusion. A permanent biventricular pacemaker was later implanted, and she was safely discharged to a nursing home.CONCLUSIONTemporary transvenous pacing through the coronary sinus, a novel approach to treat unstable bradycardia, may reduce ventricular dyssynchrony.     

Progressive and persistent atrial inexcitability

Sinus node disease is characterized by the presence of significant sinus bradycardia or prolonged sinus pauses, and is attributed to either primary failure of sinus node automaticity or sino-atrial conduction disturbance. We present two patients with symptomatic bradycardia due to idiopathic global atrial inexcitability.     

Preliminary Evaluation of a Dual Chamber Pacemaker with Bradycardia Diagnostic Functions

LASCAULT, G., et al .: Preliminary Evaluation of a Dual Chamber Pacemaker with Bradycardia Diagnostic Functions . Unexplained syncope is the main indication for the implantation of a diagnostic pacemaker. Studies on those implanted have shown that in patients with unexplained syncope, the diagnosis of paroxysmal bradycardia was feasible and reliable. The present study was designed to evaluate a new bradycardia diagnosis algorithm, loaded in a dual chamber pacemaker, in 24 patients considered as candidates for diagnostic pacemakers. During a mean follow-up of 153 days, at least one bradycardia episode was recorded in 13 patients. The mean number of detected bradycardias was 6 and the median was 3. The mean delay between the algorithm activation and the first bradycardia episode was 67 days. The mechanism of bradycardia was atrioventricular block in 6 patients, sinus node dysfunction in 6 patients, and consecutive blocked atrial premature beats in 1 patient, as indicated by the event markers. In 11 patients bradycardia was recorded during the daytime only or day and night. In two patients the episodes were recorded only at night. Overall, the algorithm was well-tolerated; however, some mild symptoms were observed due to the method of bradycardia determination, allowing bradycardia. Three patients were symptomatic as a direct result of the algorithm operation, and four patients had symptoms related to the single chamber operation of the pacemaker while functioning in the diagnosis mode (VDI). These symptoms were relieved with DDD pacing.     

Ambulatory electrocardiography in the elderly: an audit

In a retrospective analysis of 264 episodes of ambulatory electrocardiography (AECG) in 252 elderly out-patients the overall diagnostic yield was only 12 per cent. However, AECG was found to be of significant value in detecting symptomatic tachyarrhythmias, and in confirming the diagnosis of the 'sick sinus syndrome'. The AECG results influenced the management plan in at least 16 per cent, and changes in drug treatment in 10 per cent. When interpreted critically, AECG is useful tool in the investigation of elderly patients with symptoms such as syncope, faintness, dizziness and unexplained falls.     

Abdominal distention as an indication of post-polio ventilatory insufficiency. Clinical note

Post-polio patients may experience episodes of recurrent respiratory insufficiency even after years of relatively stable pulmonary function. This patient's case was clearly documented with pulse oxymetry at night. Her major complaint, that of abdominal distension, was successfully addressed with the use of negative pressure ventilation. The likely cause of the abdominal distension was the excessive swallowing of air during episodes of ventilatory insufficiency. The goal of care for this patient was a safer, less stressful, more comfortable and restful nighttime routine with less daytime fatigue. The symptom of abdominal distention served as an indicator of a significant threat to her well being. Psychological support was a key element in her acceptance of the use of the ventilatory support equipment.     

Contribution of a Pacemaker Bradycardia Detection Algorithm in the Study of Patients with Carotid Sinus Syndrome

While carotid sinus syndrome (CSS) is often suspected as a cause of syncope in the elderly, whether it represents an indication for cardiac pacing may remain uncertain. Bradycardia algorithms included in pacemakers are now able to establish a precise relationship between spontaneous asystole and occurrence of symptoms and strengthen the indication for permanent pacing. This study included seven men and three women (70.5 +/- 7.3 years of age) who, over an average period of 54.1 +/- 17 months, had suffered from syncope (12.6 episodes/patient) and presyncope (11.2 episodes/patient) attributed to pure cardioinhibition (2 patients) or mixed CSS (8 patients). Other sources of symptoms were excluded by thorough clinical evaluations, including Holter monitoring, echocardiography, and electrophysiological testing. All patients received a CHORUS 6234 pacemaker, the memory of which includes a dedicated bradycardia detection algorithm capable of storing atrial and ventricular chains, and date and time of the last ten pauses and/or bradycardic events. After a initial period of 14.7 +/- 8 months, during which symptoms were suppressed, the bradycardia algorithm was activated. From then on, a cumulative increase in the number of patients presenting with diurnal pauses was measured (1 month, n = 0; 3 months, n = 6; 9 months, n = 7; 2 years, n = 8). Fourteen episodes of diurnal asystole were recorded. The mean duration of the longest episodes of spontaneous ventricular standstill was 6,319 +/- 1,615 ms and was due to sinoatrial block (n = 7), atrioventricular block (n = 5), and a combination of both (n = 2). In conclusion, activation of the CHORUS bradycardia algorithm allowed confirmation of the appropriateness of permanent pacing in a majority of patients suffering from CSS.     

Clinical significance of intrinsic sympathomimetic activity of the beta blocker carteolol. II: Comparative studies of carteolol and pindolol in patients with bradycardia

Completing previous studies in patients with sinus bradycardia (Med. Klin. 82 [1987], 647-650) we compared metoprolol with carteolol and pindolol, pindolol with carteolol, no treatment with carteolol (in two groups) in five series of the paired comparisons of Holter-ECG each. With change from metoprolol to carteolol or pindolol (dose ratio 10:1) lowest heart rate on Holter-ECG increased by 28 or 29% without change of exercise heart rate. Direct comparison of pindolol and carteolol revealed a very similar heart rate profile, indicating equipotent beta blockade and ISA. In patients with previous beta blocker induced bradycardia, carteolol did not change a normal resting heart rate off treatment. However, in patients with spontaneous sinus bradycardia carteolol increased lowest heart rate (+14%, due to overriding ISA) and lowered exercise heart rate (-15%, due to overriding beta blockade). A beta blocker induced sinus bradycardia consistently improved with change of treatment to carteolol and pindolol. With caution carteolol and pindolol may also be used despite spontaneous sinus bradycardia.     

Cardiac emergencies caused by honey ingestion: a single centre experience

An unusual type of food poisoning is commonly seen in the Black Sea coast of Turkey attributable to andromedotoxin containing toxic honey ingestion. This study is a retrospective case series of 19 patients admitted to an emergency department in 2002, poisoned by "mad" honey. All of the patients had the complaints of nausea, vomiting, sweating, dizziness, and weakness, several hours after ingesting "mad" honey. Physical examination showed hypotension in 15 patients, sinus bradycardia in 15, and complete atrioventricular block (AVB) in four patients on admission. Two patients with bradycardia and two with AVB fell and injured their heads. Three of them presented with local haematoma. One patient had a 6 cm cut on his head without any neurological deficit and his cranial computed tomography imaging was normal. Hypotension and conduction disorders resolved with atropine treatment, resulting in complete recovery within 24 hours.     

Acute myocardial infarction complicated by hemodynamically unstable bradyarrhythmia: prehospital and ED treatment with atropine

The purpose of this study was to investigate the therapeutic response to atropine of patients experiencing hemodynamically compromising bradyarrhythmia related to acute myocardial infarction (AMI) in the prehospital (PH) setting and the therapeutic impact of the PH response to atropine on further Emergency Department (ED) care. In addition, the prevalence of AMI in patients presenting with atrioventricular block (AVB) is noted. Retrospective review of PH, emergency department (ED), and hospital records. PH patients, with hemodynamically compromising bradycardia or AVB with evidence of spontaneous circulation, who received atropine as delivered by emergency medical services (EMS) personnel, were used. Urban/suburban fire department-based emergency medical services (EMS) system with on-line medical control serving a population of approximately 1.6 million persons. Hemodynamic instability was defined as the presence of any of the following: ischemic chest pain, dyspnea, syncope, altered mental status, and systolic blood pressure less than 90 mm Hg. Bradycardia was defined as sinus bradycardia, junctional bradycardia, or idioventricular bradycardia (grouped as bradycardia), whereas AVB included first-, second- (types I and II), or third-degree (grouped as AVB). The response that occurred within 1 minute of atropine dosing was recorded as none, partial, complete, or adverse. Comparisons were made between patients with AMI and non-AMI hospital discharge diagnoses. The diagnosis of AMI was confirmed by abnormal elevations in creatinine phosphokinase MB fraction. One hundred seventy-two patients meeting entry criteria were identified. Of these, 131 (76.1%) had complete PH, ED, and hospital records and were used for data analysis. Forty-five patients (34.3%) had a primary hospital discharge diagnosis of AMI; the remaining patients had a non-AMI discharge diagnosis. AMI patients were significantly younger (67 +/- 12 v 73 +/- 13 years, P = .025), were less likely to have a history of heart disease (35.5% v54.7%, P = .038), and were more likely to present with chest pain (68.9% v24.4%, P < .001) or hypotension (60% v37.2%, P = .013) compared with non-AMI patients. Forty-five of 131 patients presented with AVB, of which 25 had a hospital discharge diagnosis of AMI (55.6%). The mean time from first dose of atropine to ED arrival and the total dose of atropine received in the PH setting did not differ between AMI and non-AMI groups (15.2 +/- 7.7 v 16.2 +/- 8.7 minutes, P= .5; and 0.9 +/- 0.49 v 1.0 +/- 0.58 mg, P = .25). The likelihood of achieving normal sinus rhythm in the PH setting did not differ between AMI and non-AMI groups (40% v 18.6%, P = .07). No differences were found between AMI and non-AMI groups in the amount of additional atropine given (1.2 +/- 0.58 v 1.3 +/- 1.1 mg, P = .58) or the use of other resuscitative therapies after ED arrival (isoproterenol, 13.3% v12.8%, P = .93; dopamine, 28.9% v26.7% P = .79; transcutaneous pacing, 26.7% v26.7%, P = .99; transvenous pacing, 8.9% v5.8%, P = .51), with the exception of thrombolytic therapy (24.4% v 0%, P< .001) and cardiac catheterization (22.2% v3.4%, P = .001). Despite a lack of significant difference in achieving a normal sinus rhythm in the prehospital or ED setting, AMI patients were more likely to achieve a normal sinus rhythm over the total course of PH and ED care than non-AMI patients (44.4% v24.4%, P = .019). Hemodynamically unstable (by ACLS criterion) AVB presenting in the PH setting is associated with a hospital diagnosis of AMI in most (55.6%) patients in this study. AMI patients with hemodynamically unstable AVB or bradycardia are no more likely to respond to atropine therapy in the PH setting than patients with non-AMI hospital diagnoses. Finally, although there is no difference in the treatment of compromising AVB or bradycardia received by AMI versus non-AMI patients in the PH or ED setting, AMI patients are more likely to achieve a normal sinus rhythm over the t