The effect of amiodarone in the Wolff-Parkinson-White syndrome was studied with programmed electrical stimulation of the heart in 15 patients. All 15 patients had circus movement tachycardias; 7 also had atrial fibrillation. Programmed electrical stimulation was performed before and after 14 days of oral administration of amiodarone. The effective refractory period of the accessory pathway lengthened in an atrioventricular direction in all patients and in a ventriculoatrial direction in eight patients. The effective refractory period of the atrium and ventricle lengthened in 14 and 12 patients, respectively. After administration of amiodarone, circus movement tachycardia could no longer be initiated in five patients. The zone of tachycardia narrowed in four patients, did not change in two and increased in seven. The effect of amiodarone on initiation of circus movement tachycardia could be related to differences in effect of the drug and in the mechanism of tachycardia in individual patients. In all patients in whom tachycardias could still be initiated after treatment with amiodarone the heart rate during tachycardia was slower than before treatment. This slowing was caused by a decrease in conduction velocity of the circulatory wave in different parts of the tachycardia circuit. The effect of amiodarone in prolonging the refractory period of the accessory pathway makes this drug especially useful in patients with the Wolff-Parkinson-White syndrome and atrial fibrillation.
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http://dx.doi.org/10.1016/0002-9149(76)90148-x | DOI Listing |
J Interv Card Electrophysiol
January 2025
Department of Cardiovascular Medicine, Dokkyo Medical University, 880 Kitakobayashi, Mibu, Shimotsugagun, Tochigi, 321-0293, Japan.
Background: The conventional mapping approach for the atrioventricular accessory pathway (AP) involves point-by-point mapping to identify the connection sites of the AP to the atria or ventricle and accurate interpretation of local electrograms. Omnipolar mapping technology (OMT) explains how vector and wave speed are produced by using both unipolar and bipolar signals to obtain omnipolar signals, directions, and conduction velocity. The aim of this study is to verify the effectiveness of OMT for catheter ablation of AP.
View Article and Find Full Text PDFEur Heart J Case Rep
January 2025
Arrhythmology, Pacing and Electrophysiology Unit, Cardiology Service, Santa Marta Hospital, Central Lisbon Hospital University Centre, R. de Santa Marta 50, Lisboa 1169-024, Portugal.
Background: Accessory pathways (AP) are associated with an increased risk of atrioventricular reentry tachycardia (AVRT), presenting as a wide QRS tachycardia if the mechanism is antidromic. Rarely, AVRT may not respond to adenosine, suggesting a duodromic mechanism if the patient has multiple APs. Herein, we present a case of a male patient with multiple APs, wide QRS complex tachycardia, and resistance to adenosine.
View Article and Find Full Text PDFEur J Case Rep Intern Med
December 2024
Internal Medicine, Holy Family Hospital, Rawalpindi, Pakistan.
Background: Andersen-Tawil syndrome (ATS) is a rare autosomal dominant disorder caused by variants in the gene. It is associated with periodic paralysis, dysmorphic features and cardiac arrhythmias. The syndrome exhibits incomplete penetrance, leading to a broad spectrum of clinical manifestations, making diagnosis challenging.
View Article and Find Full Text PDFCardiol Young
January 2025
Department of Cardiovascular Surgery, Hacettepe University, Ankara, Turkey.
Background: Ebstein's anomaly represents 40% of congenital tricuspid valve abnormalities. Studies about paediatric Ebstein's anomaly patients are limited.
Aim: To evaluate clinical characteristics, treatment (medical/arrhythmia ablation/surgical) results, and outcome of Ebstein's anomaly patients, and to determine factors affecting arrhythmia presence and mortality.
Cardiol Young
January 2025
Saitama Children's Medical Center, Division of Pediatric Cardiology, Saitama, Japan.
Background: The Wolff-Parkinson-White pattern is a delta wave frequently detected in school-based cardiovascular screening programs in Japan. Although most children with Wolff-Parkinson-White pattern are asymptomatic, initial symptoms may include syncope or sudden death, necessitating accurate diagnosis and management. Delta waves can also indicate a fasciculoventricular pathway, which poses no risk and does not require management.
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