1/15. Accurate diagnosis of convulsive syncope: role of an implantable subcutaneous ECG monitor.Convulsive syncope due to transient bradycardia is recognized as a cause of treatment-resistant seizures. However, the diagnosis may be difficult to make with conventional electrocardiographic devices if attacks are infrequent. We present a case of apparent epilepsy in which a new implantable electrocardiographic event recorder (the 'Reveal' insertable loop recorder) was used to show that attacks were caused by prolonged asystole of up to 36 s in duration. The insertable loop recorder may have an important role in the investigation of patients with treatment-resistant seizures, particularly where there is a strong suspicion of an underlying cardiac arrhythmia.- - - - - - - - - - ranking = 1keywords = bradycardia (Clic here for more details about this article) |
2/15. Hemodynamic during a postexertional asystolia in a healthy athlete: a case study.Hemodynamic events leading to spontaneous postexertional vasovagal syncope are not completely understood because of the lack of beat-to-beat data. We report a case study of a young athlete who undergoes a syncopal episode during the recovery period following a maximal cycle-ergometer test. The episode was monitored by an impedance cardiograph which can gather noninvasively beat-to-beat the flow of heart rate (HR), stroke volume (SV), cardiac output (CO), diastolic filling rate (SV/DT), and myocardial contractility index (PEP/LVET). The most important findings of this report are the dramatic reduction of SV/DT preceding the syncope, the increment of SV together with the reduction of HR preceding and following the syncope, the prompt recovery of CO values after the syncopal episode despite the bradycardia, and the reduction of PEP/LVET after the syncope. This report confirms the importance of active recovery immediately after strenuous exercise and supports the hypothesis that the reduction of SV/DT in the presence of an inotropic stimulation can trigger the vasovagal reaction.- - - - - - - - - - ranking = 1keywords = bradycardia (Clic here for more details about this article) |
3/15. syncope after effort.A 29-year-old man developed recurrent syncope following exertion. Cardiac investigations revealed no evidence of structural heart disease, but during exercise testing, in the recovery phase, he sustained a bradycardia and then asystole for a prolonged period. Before cardiac massage could be instituted a tonic-clonic fit occurred, and this initiated a return to sinus rhythm. His symptoms were abolished following the implantation of a dual-chamber pacemaker.- - - - - - - - - - ranking = 1keywords = bradycardia (Clic here for more details about this article) |
4/15. Neurally mediated syncope induced by lung cancer--a case report.The authors present hemodynamic and autonomic features of recurrent and episodic neurally mediated syncope in a man with lung cancer involving afferent vagus. He revealed extreme hypotension with bradycardia occurring during sitting or standing. A head-up tilt test also induced syncope. However, syncope attacks no longer occurred 2 weeks after admission. Alternatively, the paralyses of the left recurrent laryngeal nerve and the left phrenic nerve developed. It is suggested that the lung cancer involved upper rootlets of the left vagus and caused transient hypersensitivity of baroreceptor function that resulted in neurally mediated syncope.- - - - - - - - - - ranking = 1keywords = bradycardia (Clic here for more details about this article) |
5/15. Decreased bispectral index as an indicator of syncope before hypotension and bradycardia in two patients with needle phobia.We report two cases who exhibited a decrease in their bispectral index (BIS) score, associated with syncope during venipuncture in patients with suspected needle phobia. In case 1, the reduction in BIS score occurred during the development of hypotension and bradycardia and may well have been caused by cerebral hypoperfusion. In case 2, the patient lost consciousness with decreasing BIS score before hypotension and bradycardia; this patient's condition could not be completely explained by cerebral hypoperfusion as a result of a vasovagal reflex because the patient's blood pressure and heart rate remained normal during the syncopal episode.- - - - - - - - - - ranking = 6keywords = bradycardia (Clic here for more details about this article) |
6/15. A patient with recurrent syncope and ST-elevation on the electrocardiogram.A 56-year old woman had over 100 episodes of syncope since the age of 8. Because the patient's description of the episodes suggested vasovagal syncope she was studied by a head up tilt test (HUT). Seconds after the uncomplicated HUT the patient experienced a typical syncope with bradycardia, marked ST-elevation and chest pain. After treatment with nifedipine she has had one syncopal spell in a follow up period of 31 months. We conclude that the syncopal events in this patient were caused by a combination of vasovagal syncope and coronary spasm.- - - - - - - - - - ranking = 1keywords = bradycardia (Clic here for more details about this article) |
7/15. Vasovagal response induced by a low dose of isoproterenol infusion before tilting-up.A 56 year-old man was referred to hospital for evaluation of syncopal episodes. During head-up tilt testing, his symptom was reproduced, associated with bradycardia and hypotension, by a low dose of isoproterenol (0.02 microg. kg (-1). min(-1)) infusion in the supine position before tilting-up. isoproterenol infusion can provoke a vasovagal response without tilting. Careful observation of the patient's hemodynamics is mandatory not only during tilting, but also in the supine position before tilting-up.- - - - - - - - - - ranking = 1keywords = bradycardia (Clic here for more details about this article) |
8/15. When the heart is stopped for good: hypotension-bradycardia paradox revisited.In vasovagal syncope, occurrence of bradycardia/asystole in the wake of hypotension has often been considered paradoxical. The major objective of this teaching module is to critically examine the pathophysiological mechanism and significance of the hypotension-bradycardia paradox unique to this condition. We narrate here how we discussed the pathophysiology of vasovagal syncope in a large classroom session attended by 275 doctors and medical students. A case study was used to describe the typical clinical presentation of vasovagal syncope. The pathophysiological mechanisms involved were then discussed systematically using a series of open-ended questions. We made it clear 1) that the occurrence of bradycardia or asystole in the face of acute severe hypotension is a mechanism to possibly minimize further blood loss, prevent myocardial damage, and increase ventricular filling; and 2) that fainting, which occurs as a consequence of this, is a homeostatic mechanism that serves to restore venous return and cerebral blood flow before blood pressure is normalized by neural reflex mechanisms. Eighty-four percent of participants reported that they were satisfied with the session. The information contained herein could be used to explain to any suitable audience the neural regulation of blood pressure in the face of acute severe hypotension and the pathophysiology of vasovagal syncope.- - - - - - - - - - ranking = 7keywords = bradycardia (Clic here for more details about this article) |
9/15. Vasodepressor syncope due to subclinical myocardial ischemia.INTRODUCTION: Vasodepressor syncope is a common cause of syncope, but the initiating event that triggers the vasodepressor response remains incompletely understood. Although ischemia due to acute right coronary occlusion may precipitate hypotension and bradycardia through the Bezold-Jarisch reflex, an ischemic precipitant for the common vasodepressor faint has not been previously identified. In the present study, we present evidence for a causal relationship between myocardial ischemia and vasodepressor syncope. methods AND RESULTS: Two patients referred for evaluation of syncope underwent upright tilt table testing with either ST segment monitoring, sestamibi scintigraphy and echocardiography during the tilt test, or coronary angiography. Both patients had positive tilt table tests during the control study. Patient 1 was documented to have reproducible ischemic ECG changes during atypical chest pressure induced by upright tilt, despite a normal coronary angiogram with ergonovine provocation. Subsequent tilt testing with simultaneous sestamibi perfusion imaging and echocardiography revealed reversible anterolateral hypoperfusion corresponding with anterolateral hypokinesis during upright tilt that preceded syncope. Ischemic ECG changes during incremental rapid atrial pacing further suggested ischemia on the basis of microvascular disease. Follow-up tilt testing on verapamil was negative. Patient 2 developed ischemic ECG changes during the recovery phase of an exercise stress test, which was followed by a vasodepressor response and frank syncope. coronary angiography revealed a 90% distal right coronary artery stenosis that was successfully dilated, after which follow-up tilt table testing off all other medication was negative. CONCLUSIONS: These two cases illustrate a previously unrecognized causality between myocardial ischemia and clinical vasodepressor syncope, and demonstrate that subtle manifestations of myocardial ischemia, associated with either atypical angina or silent ischemia, can provoke syncope.- - - - - - - - - - ranking = 1keywords = bradycardia (Clic here for more details about this article) |
10/15. Vasovagal syncope: asystole provoked by head-up tilt testing under sertraline therapy.syncope is defined as a sudden transient loss of consciousness. Vasovagally mediated hypotension and bradycardia are believed common, yet difficult to diagnose, causes of syncope in healthy children and adolescents. These episodes are often both sudden and sporadic in nature and, if recurrent and severe (malignant vasovagal syncope), can be a source of morbidity and possibly mortality. head-up tilt testing has emerged as a useful investigation in patients who are thought to have recurrent vasovagal syncope with systemic hypotension, bradycardia, or both, and it has been suggested as a potential method to test for vasovagal episodes. sertraline hydrochloride, a serotonin reuptake inhibitor, has been reported to be effective in preventing the vasovagal syncopal episodes in children and adults. Here, two cases of recurrent, unexplained syncope are presented. Both were under sertraline therapy and underwent provocative head-up tilt testing that resulted in asystole.- - - - - - - - - - ranking = 2keywords = bradycardia (Clic here for more details about this article) |
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