1/170. adenosine-induced atrial pro-arrhythmia in children.adenosine has become the preferred acute treatment for common types of supraventricular tachycardia because of its efficacy and safety. There have been a few reports of serious proarrhythmic events associated with its use, including the induction of atrial fibrillation in adult patients. Three instances of adenosine-induced atrial proarrhythmia (two atrial fibrillation and one atrial flutter) have been observed in children with manifest or concealed wolff-parkinson-white syndrome at the Hospital for Sick Children, Toronto, ontario since 1990, which indicates a previously unreported risk of atrial arrhythmia for children as well. Because adenosine may enhance antegrade bypass tract conduction, its use carries a risk of ventricular acceleration, including progression to ventricular fibrillation. Because of such rare and potentially life-threatening adverse effects, appropriate monitoring and precautions are required during the administration of the drug to children and adults.- - - - - - - - - - ranking = 1keywords = rhythm (Clic here for more details about this article) |
2/170. ST segment elevation in the right precordial leads induced with class IC antiarrhythmic drugs: insight into the mechanism of brugada syndrome.We evaluated two patients without previous episodes of syncope who showed characteristic ECG changes similar to brugada syndrome following administration of Class IC drugs, flecainide and pilsicainide, but not following Class IA drugs. Patient 1 had frequent episodes of paroxysmal atrial fibrillation resistant to Class IA drugs. After treatment with flecainide, the ECG showed a marked ST elevation in leads V2 and V3, and the coved-type configuration of ST segment in lead V2. A signal-averaged ECG showed late potentials that became more prominent after flecainide. Pilsicainide, a Class IC drug, induced the same ST segment elevation as flecainide, but procainamide did not. Patient 2 also had frequent episodes of paroxysmal atrial fibrillation. Pilsicainide changed atrial fibrillation to atrial flutter with 2:1 ventricular response, and the ECG showed right bundle branch block and a marked coved-type ST elevation in leads V1 and V2. After termination of atrial flutter, ST segment elevation in leads V1 and V2 continued. In this patient, procainamide and quinidine did not induce this type of ECG change. In conclusion, strong Na channel blocking drugs induce ST segment elevation similar to brugada syndrome even in patients without any history of syncope or ventricular fibrillation.- - - - - - - - - - ranking = 0.57142857142857keywords = rhythm (Clic here for more details about this article) |
3/170. Preterm labor and accidental hemorrhage after disopyramide therapy in pregnancy. A case report.BACKGROUND: Treatment of arrhythmias during pregnancy is complicated by concerns about the safety of antiarrhythmic therapy. This is the first case report of preterm labor and abruptio placentae following the administration of disopyramide during pregnancy. CASE: A 26-year-old woman, gravida 2, para 1, was diagnosed as having wolff-parkinson-white syndrome during the third trimester of pregnancy. Recurrent episodes of supra-ventricular tachycardia were refractory to medical therapy and required repeated direct current cardioversion. Administration of disopyramide led to the initiation of painful uterine contractions and accidental hemorrhage. CONCLUSION: Caution must be exercised during the use of disopyramide during pregnancy, and intensive monitoring should be instituted to avoid adverse maternal and fetal effects.- - - - - - - - - - ranking = 0.28571428571429keywords = rhythm (Clic here for more details about this article) |
4/170. Ibutilide for termination of atrial fibrillation in the wolff-parkinson-white syndrome.Ibutilide promptly restored sinus rhythm on two occasions in an elderly patient with AF and rapid ventricular response associated with the WPW syndrome. As a selective Class III antiarrhythmic agent that prolongs cardiac refractoriness, ibutilide offers an alternative effective therapy for rapid termination of AF in WPW.- - - - - - - - - - ranking = 0.28571428571429keywords = rhythm (Clic here for more details about this article) |
5/170. electrocardiography in the patient with the wolff-parkinson-white syndrome: diagnostic and initial therapeutic issues.The wolff-parkinson-white syndrome (WPW), estimated to occur in approximately 0.1% to 3% of the general population, is a form of ventricular preexcitation involving an accessory conduction pathway. The definition of WPW relies on the following electrocardiographic features: (1) a PR interval less than 0.12 seconds (2) with a slurring of the initial segment of the QRS complex, known as a delta wave, (3) a QRS complex widening with a total duration greater than 0.12 seconds, and (4) secondary repolarization changes reflected in ST segment-T wave changes that are generally directed opposite (discordant) to the major delta wave and QRS complex changes. The accessory pathway bypasses the atrioventricular (AV) node, creating a direct electrical connection between the atria and ventricles. The majority of patients with preexcitation syndromes remain asymptomatic throughout their lives. When symptoms do occur they are usually secondary to tachyarrhythmias; the importance of recognizing this syndrome is that these patients may be at risk to develop a variety of supraventricular tachyarrhythmias which cause disabling symptoms and, in the extreme, sudden cardiac death. The tachyarrhythmias encountered in the WPW patient include paroxysmal supraventricular tachycardia (both the narrow QRS and wide QRS complex varieties), atrial fibrillation, atrial flutter, and ventricular fibrillation. Diagnostic and urgent, initial therapeutic issues based on initial electrocardiographic information are presented via 5 illustrative cases.- - - - - - - - - - ranking = 0.42857142857143keywords = rhythm (Clic here for more details about this article) |
6/170. Familial hypokalemic periodic paralysis and wolff-parkinson-white syndrome in pregnancy.PURPOSE: To describe the anesthetic and obstetrical management of a pregnant patient with co-existing Familial hypokalemic periodic paralysis (FHPP) and wolff-parkinson-white syndrome (WPW). CLINICAL FEATURES: A 29 yr-old primigravida with FHPP and WPW presented to the antenatal clinic at 18 wk gestation, for consideration of her anesthetic and obstetrical management during labour and delivery. A plan was constructed to avoid the known precipitating factors of FHPP including carbohydrate loading, cold, mental stress and exercise, which could lead to acute attacks of weakness. She presented for induction of labour at 41 wk and three days. An epidural catheter was sited early in labour. The second stage was limited to less than one hour. She had a rotational forceps delivery for which the epidural was extended to provide anesthesia. A healthy male baby was delivered. The patient made an uncomplicated recovery and was discharged home on the second postnatal day. The peripartum potassium was kept within the normal range with intravenous as well as oral potassium supplementation. No arrhythmias were reported. CONCLUSION: Assessment of the patient at an early stage in her pregnancy allowed for a multidisciplinary approach to this patient and her medical problems. A plan was made to avoid known precipitating factors during labour, delivery and the postnatal period well in advance of her date of confinement, leading to a successful outcome for mother and child.- - - - - - - - - - ranking = 0.14285846857105keywords = rhythm, hour (Clic here for more details about this article) |
7/170. Development of rapid atrial fibrillation with a wide QRS complex after neostigmine in a patient with intermittent wolff-parkinson-white syndrome.We report the case of a 67-yr-old man with intermittent Wolff-Parkinson-White (WPW) syndrome in whom neostigmine produced life-threatening tachyarrhythmias. The patient was scheduled for microsurgery for a laryngeal tumour. When he arrived in the operating room, the electrocardiogram showed normal sinus rhythm with a rate of 82 beat min-1 and a narrow QRS complex which remained normal throughout the operative period. On emergence from anaesthesia, the sinus rhythm (87 beat min-1) changed to atrial fibrillation with a rate of 80-120 beat min-1 and a normal QRS complex. We did not treat the atrial fibrillation because the patient was haemodynamically stable. neostigmine 1 mg without atropine was then administered to antagonize residual neuromuscular block produced by vecuronium. Two minutes later, the narrow QRS complexes changed to a wide QRS complex tachycardia with a rate of 110-180 beat min-1, which was diagnosed as rapid atrial fibrillation. As the patient was hypotensive, two synchronized DC cardioversions of 100 J and 200 J were given, which restored sinus rhythm. No electrophysiological studies of anticholinesterase drugs have been performed in patients with WPW syndrome. We discuss the use of these drugs in this condition.- - - - - - - - - - ranking = 0.57142857142857keywords = rhythm (Clic here for more details about this article) |
8/170. Late onset of accessory pathway conduction in a patient with complete AV block.This case report discusses a patient with complete AV block in early childhood. The patient required a permanent pacemaker. At 6 years of age, intermittent preexcited beats were noted on telephonic transmissions. At 7 years of age, 1:1 preexcitation was noted in sinus rhythm. Therefore, late onset of antegrade accessory pathway function is demonstrated. This case provides evidence of developmental changes in accessory pathways. This may explain age related differences in the onset of narrow complex tachycardia in the school age years.- - - - - - - - - - ranking = 0.14285714285714keywords = rhythm (Clic here for more details about this article) |
9/170. atrial fibrillation and continuous hypotension induced by sildenafil in an intermittent WPW syndrome patient.A 55-year-old Japanese man was hospitalized for palpitations and severe chest oppression one hour after he ingested about 1500 ml of beer and sildenafil (Viagra) 50 mg. At 43 years of age, he had been diagnosed with intermittent WPW syndrome following a paroxysmal supraventricular tachycardia (PSVT) attack. He took a 1 mg tablet of doxazosin daily for mild hypertension. On admission, his blood pressure was 90/54 mmHg and his heart beat was weak and irregular with a rate of about 220/min. Since atrial fibrillation (Af) was diagnosed on an electrocardiogram (minimum RR interval; 0.22 seconds), direct current shock was performed with 100 joules and 150 joules but conversion to sinus rhythm failed. Sinus rhythm returned spontaneously from Af four hours after taking sildenafil. Since blood pressure was 50/17 mmHg despite the return to sinus rhythm, blood pressure was maintained by dopamine for twelve hours after sinus rhythm returned. The patient underwent catheter ablation for curative therapy and thereafter has not had any further episodes of tachycardia.- - - - - - - - - - ranking = 0.57143254857029keywords = rhythm, hour (Clic here for more details about this article) |
10/170. Transient appearance of antegrade conduction via an AV accessory pathway caused by atrial fibrillation in a patient with intermittent wolff-parkinson-white syndrome.A 55 year old man with intermittent Wolff-Parkinson-White (WPW) syndrome had an episode of atrial fibrillation (AF) that lasted for 117 days. After interruption of the AF a Delta wave appeared that lasted for two days and then disappeared. exercise stress and isoprenaline infusion could not reproduce the Delta wave, but after another episode of AF which lasted for seven days a persistent Delta wave appeared that lasted for six hours. In an electrophysiological study performed on a day without a Delta wave, neither antegrade nor retrograde conduction via an accessory pathway was seen, but after atrial burst pacing (at 250 ms cycle length) for 10 minutes, a Delta wave appeared lasting for 16 seconds. Atrial electrical remodelling-that is, the shortening of the atrial effective refractory period caused by AF, is a possible mechanism of the appearance of the Delta wave.- - - - - - - - - - ranking = 1.3257139070374E-6keywords = hour (Clic here for more details about this article) |
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