1/171. tachycardia induced tachycardia: case report of right ventricular outflow tract tachycardia and AV nodal reentrant tachycardia.tachycardia induced tachycardia, or so called double tachycardia, is rare. A 34 year old woman is described who had a history of syncope, frequent extrasystoles, and episodes of non-sustained ventricular tachycardia, perceived as palpitation, without syncope. At electrophysiological study, during infusion of isoprenaline, an episode of non-sustained ventricular tachycardia arising from the right ventricular outflow tract initiated sustained atrioventricular nodal reentrant tachycardia, thought to be the cause of the patient's syncope. Ablation of the right ventricular outflow tract focus abolished the ventricular ectopy; the slow AV nodal pathway was also ablated. The patient no longer has either syncope or palpitation.- - - - - - - - - - ranking = 1keywords = long (Clic here for more details about this article) |
2/171. Potential proarrhythmic effects of implantable cardioverter-defibrillators.Implantable cardioverter-defibrillator (ICD) interventions have the potential to be proarrhythmogenic. New arrhythmias can occur in the setting of clinically appropriate therapies, as well as during a cardiac rhythm for which therapy is not intended. Cardioversion/defibrillation therapies, antitachycardia pacing, and antibradycardia pacing are potential triggers for the development of new arrhythmias. Newer ICDs allow better recognition and interpretation of the arrhythmias that are induced by delivered therapies. Two cases of ICD-induced proarrhythmias are described. Based on the course of these patients and review of previous reports, proarrhythmic effects of ICD interventions along with prevention and management strategies are discussed.- - - - - - - - - - ranking = 1keywords = long (Clic here for more details about this article) |
3/171. hypokalemia with syncope caused by habitual drinking of oolong tea.A 61-year-old woman developed hypokalemia, atrioventricular block and ventricular tachycardia with syncope after habitual drinking 2 to 3 liters of oolong tea per day. She had been suffering from rheumatoid arthritis and sjogren's syndrome and her serum albumin was decreased (2.9 g/dl). Oolong tea contains caffeine at approximately 20 mg/dl. Great quantities of caffeine can induce hypokalemia. The serum protein binding caffeine is albumin. Accordingly, in patients with hypoalbuminemia, caffeine is apt to induce hypokalemia. This case suggested that great quantities of oolong tea, one of the so-called "healthy" drinks, result in serious symptoms for patients with hypoalbuminemia.- - - - - - - - - - ranking = 7keywords = long (Clic here for more details about this article) |
4/171. Radiofrequency catheter ablation of idiopathic right ventricular tachycardia near the His bundle.There are only a few reports on successful radiofrequency catheter ablation of idiopathic right ventricular tachycardia (VT) originating from other sites than right ventricular outflow tract. We report here a case of VT which exhibited an inferior-axis and a left bundle branch block pattern and originated near the His bundle. Using the temperature-controlled ablation catheter, prudent observation of the fluoroscopy and intracardiac electrograms during pacemapping, we successfully ablated the origin of the VT without any conduction disturbance. However, further study is required to determine the effectiveness of catheter ablation and the long term prognosis for this type of VT.- - - - - - - - - - ranking = 1keywords = long (Clic here for more details about this article) |
5/171. A variant of long qt syndrome manifested as fetal tachycardia and associated with ventricular septal defect.Two patients with a novel variant of long qt syndrome are described. The clinical course was characterised by an in utero onset of ventricular tachycardia and atrioventricular block (at 26 and 30 weeks' gestational age, respectively), and an association with a ventricular septal defect. Studies of both patients' families identified relatives with prolonged QT interval, syncope, or sudden death. One patient died of intractable ventricular tachycardia at 4 days old. The other received beta blocker treatment and a pacemaker. She died suddenly at the age of 10 months. The unique association with ventricular septal defect and the malignant clinical course warrants further molecular diagnosis of this novel variant of long qt syndrome.- - - - - - - - - - ranking = 7keywords = long (Clic here for more details about this article) |
6/171. hyperkalemia probably reverses the antiarrhythmic effects of amiodarone: a case report.Sustained monomorphic ventricular tachycardia (VT) developed in a 58-year-old man with acute myocardial infarction and end-stage renal disease. amiodarone was effective in preventing VT recurrence. Sustained VT was not induced during an electrophysiologic study. However, VT recurred during accidental hyperkalemia, which was caused by the change of dialysis therapy from peritoneal dialysis to hemodialysis. VT subsided with correction of hyperkalemia. Thereafter, VT did not recur as long as the serum potassium concentration was kept within the normal range. Several months later, the patient died suddenly because poor dietary compliance resulted in an increase in his potassium concentration. This case suggests that hyperkalemia may reverse the potent antiarrhythmic effects of amiodarone.- - - - - - - - - - ranking = 1keywords = long (Clic here for more details about this article) |
7/171. Beneficial effect of amiodarone on pacing induced terminability of reentrant ventricular tachycardia.A 33 year-old woman was referred to our hospital for further treatment of ventricular tachycardia (VT). During treatment with amiodarone (200 mg/day), clinical VT at the cycle length of 510 ms was induced. During the VT, rapid ventricular pacing was repeated at progressively shorter cycle lengths after a decrement of 10 ms steps. The VT was entrained by the rapid pacing and reproducibly terminated at a paced cycle length of 380 ms. Four weeks after reducing the amiodarone to 100 mg/day, programmed stimulation was repeated. The VT with the same morphology but with a slightly shorter cycle length of 480 ms was again induced. However, at this time, rapid pacing from the same site could not terminate VT and transient acceleration developed at a shorter paced cycle length of 260 ms. The QT (QTc) interval, effective refractory period at the pacing site and width of the paced QRS complex were similar before and after changing the amiodarone treatment. The most characteristic change of VT in the second study was a widening of the entrainment zone, which was calculated as the difference between VT cycle length and the longest pacing cycle length which interrupts VT during the entrainment (from 130 to > 220 ms), and it may be explained by the preferential shortening of the action potential duration and/or facilitation of the depressed cell to cell conduction within the reentry circuit. amiodarone must exert a preferential action in the reentry circuit and modulate the conduction property as well as the effective refractory period. We should pay close attention to the efficacy of antitachycardia pacing during the modification of amiodarone treatment.- - - - - - - - - - ranking = 1keywords = long (Clic here for more details about this article) |
8/171. Development of ventricular fibrillations with different characteristics in the local electrocardiogram: large and small amplitude of activation, and its implication for implantable cardioverter defibrillator treatment.An implantable cardioverter defibrillator (ICD) was implanted in 2 patients with ventricular tachyarrhythmia related to old myocardial infarction, and defibrillation tests were attempted at the time of ICD implantation and at 2 or 4 weeks after the operation. ventricular fibrillation (VF) was induced by T-wave shocks, but the amplitude of the ventricular electrogram was different in each VF. In most of the VFs with large ventricular electrograms, the local activity was appropriately detected. However, many undersensed beats were observed in other VFs that had fine ventricular electrograms and a longer time was needed before delivering the shock. The amplitude of the ventricular electrogram might be small in some cases of VF and this might result in undersensing and/or unsuccessful defibrillation. Close attention must be paid to the amplitude of ventricular activation in each VF to avoid possible difficulty in ICD therapy.- - - - - - - - - - ranking = 1keywords = long (Clic here for more details about this article) |
9/171. tachycardia-dependent right bundle-branch block with supernormal conduction.This paper reports the case of a 76-year-old man in whom atrial flutter with varying atrioventricular block and intermittent right bundle-branch block was found. This is the first report on tachycardia-dependent right bundle-branch block associated with supernormal conduction in a case of atrial flutter. When an impulse is conducted to the ventricles beyond 0.72 s after a QRS complex of right bundle-branch block configuration, the impulse falls after the abnormally long effective refractor period of the right bundle branch and passes through the right bundle branch. When the conducted impulse occurs within 0.72 s after a QRS complex of right bundle-branch block configuration, the impulse usually falls in the refractory period and is blocked in the right bundle branch; however, only when the impulse occurs 0.48 or 0.49 s after that does it fall in the supernormal period and passes through the right bundle branch. The findings in the present report strengthen our previous suggestion that the presence of supernormal conduction plays an important role in the initiation of reentrant ventricular tachycardia.- - - - - - - - - - ranking = 1keywords = long (Clic here for more details about this article) |
10/171. A case of primary cardiac B cell lymphoma associated with ventricular tachycardia, successfully treated with systemic chemotherapy and radiotherapy: a long-term survival case.We experienced a long-term survival case of primary cardiac lymphoma (PCL) demonstrating ventricular tachycardia (VT) as an initial sign, which was related to localized myocardial damage by lymphoma cells. A 70-year-old woman with sustained VT was admitted to the Kofu Municipal Hospital. VT ceased with the administration of disopyramide intravenously. The origin of the VT was the free wall of the right ventricular outflow tract (RVOT) as observed by electrocardiography on admission. A solitary mass in the free wall of the RVOT was found by echocardiography, chest computed tomographic scanning and magnetic resonance imaging. There was no evidence of extracardiac involvement. The patient was histologically diagnosed as PCL by endomyocardial biopsy. Chemotherapy started immediately after the diagnosis and the mass showed a marked reduction in size. After 8 cycles of chemotherapy, radiotherapy was performed. Pericardial thickness in the free wall of the RVOT developed without severe side effects. Complete remission has been maintained for 30 months after the initial diagnosis, and no recurrence and arrhythmias have been detected during the follow-up period. It was demonstrated that rapid diagnosis and chemotherapy followed by radiotherapy for PCL achieved better survival.- - - - - - - - - - ranking = 5keywords = long (Clic here for more details about this article) |
| | Next -> |