| We evaluated 39 patients >45 years old with paroxysmal supraventricular tachycardia (SVT), 21 of whom had ST-segment depression during SVT. Treadmill exercise testing, including thallium stress scintigraphy, was performed in all patients and coronary angiography in 21 patients with ST-segment depression. Based on the presence of abnormal findings on exercise electrocardiogram and/or thallium in 7 of 21 patients (33%) with ST-segment depression, with additional corroboration by angiographic data, we conclude that myocardial ischemia and coronary artery disease is one, but not the only, mechanism involved in the genesis of ST-segment depression during paroxysmal SVT. ( info) |
2/287. Antidromic reciprocating tachycardia in patients with paraseptal accessory pathways: importance of critical delay in the reentry circuit. Previous studies in patients with antidromic reciprocating tachycardia (ART) have observed a critical anatomic requirement (> 4 cm) between an antegrade bypass tract limb and a retrograde AV nodal limb. We report two patients with ART utilizing a paraseptal accessory pathway. In both cases, a critical degree of slow conduction within the circuit provides unusual electrophysiologic substrate to overcome the expected anatomical constraints. ( info) |
3/287. 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. ( info) |
4/287. Left ventricular ischemia due to coronary stenosis as an unexpected treatable cause of paroxysmal atrial fibrillation. We present a patient with exercise-induced paroxysmal atrial fibrillation who was eventually scheduled for a Cox-maze operation due to persistence of his complaints of fatigue, impaired exercise tolerance, and predominantly exercise-related irregular palpitations despite treatment with several antiarrhythmic drugs. A preoperative exercise stress test without antiarrhythmic or negative chronotropic drugs, however, showed clear evidence of myocardial ischemia. After coronary angioplasty of a significant stenosis in the left anterior descending artery, there was no recurrence of atrial fibrillation during a follow-up of 7 months. ( info) |
5/287. mitral valve prosthesis disk embolization during transeptal atrioventricular junction ablation. We report a case of disk embolization from a Bjork-Shiley mitral valve prosthesis (Shiley Inc., Irvine, CA, USA) which occurred during transeptal atrioventricular (RV) junction ablation. The disk lodged in the lower thoracic aorta. The patient was treated successfully by emergency valve replacement, and the escaped disk has been left in situ with no complications. ( info) |
6/287. Anaphylactoid reaction to adenosine. adenosine (Adenocard) is an endogenous purine nucleoside that has been approved recently for intravenous treatment of paroxysmal supraventricular tachycardia. With a serum half-life of 10 seconds, reported side effects including facial flushing, dyspnea, and chest pressure are common, but very transient. An elderly woman who received adenosine for paroxysmal supraventricular tachycardia had a prolonged anaphylactoid reaction that required pharmacological treatment. This is the first reported case of a prolonged anaphylactoid reaction to adenosine. ( info) |
7/287. caffeine intoxication: a case of paroxysmal atrial tachycardia. Caffeinism is a syndrome resulting from the excessive ingestion of caffeine and characterized primarily by cardiovascular and central nervous system manifestations. A variety of tachyarrhythmias and extrasystoles are believed to reflect the toxic, cardiotonic effects of caffeine. A case of paroxysmal atrial tachycardia (PAT) related to caffeine abuse is PAT. The importance of considering this and other less frequent conditions as potential causes for this arrhythmia is stressed. ( info) |
8/287. Symptomatic atrioventricular dual pathway double responses: a role for slow pathway ablation. Two patients with symptomatic fast/slow pathway double responses were evaluated with electrophysiology studies. Chronic palpitations were resistant or worsened by medical therapy. No reentry tachycardias were induced. A nonreentrant paroxysmal supraventricular tachycardia was documented. Radiofrequency ablation of the slow pathway was safely and successfully performed. patients remain asymptomatic for 16-18 months. Ablation of the slow pathway for this substrate is a viable option. ( info) |
| We present two cases of sudden unanticipated cardiovascular complications in patients with noncatecholamine-secreting adrenocortical adenomas during laparoscopic adrenalectomy. In the first case, the patient developed paroxysmal tachycardia and hypertension followed by ventricular fibrillation shortly after clipping of the adrenal vein. In the second case, the patient suffered hypertension and bigeminy during manipulation of the adrenal gland just around the adrenal vein. awareness of such complications during either conventional or laparoscopic adrenalectomy is important even if the operation is performed in a patient with an apparently noncatecholamine-secreting adrenocortical adenoma. ( info) |
10/287. Arrhythmias in the coronary-care unit. IV. Physiologic bases of paroxysmal tachycardia-dependent bundle branch block. Paroxysmal BBB may be either tachycardia-dependent which is referred to as "phase 3 block" or bradycardia-dependent, referred to as "phase 4 block." tachycardia-dependent BBB is related to prolonged recovery. bradycardia-dependent BBB is related to hypopolarization and SDD. These fundamental electrophysiological properties aid in understanding of transient BBB occurring during an acute MI. ( info) |