We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Spontaneous Termination of Paroxysmal Supraventricular Tachycardia Following Disappearance of Bundle Branch Block Ipsilateral to a Concealed Atrioventricular Accessory Pathway: The Role of Autonomic Tone in Tachycardia Diagnosis.
- Authors
Waxman, Menashe B.; Cupps, Christina L.
- Abstract
We present a case of an 18-year-old man with a history of palpitations in whom episodes of paroxysmal supraventricular tachycardia were easily initiated by administered atrial premature beats. In all 15 control episodes of tachycardia, functional left bundle branch block (LBBB) seen at the onset, resolved within 10-20 cycles (mean. 13.1 ± 0.95). The tachycardia ended with the normalized QRS complex in each episode. Eleven episodes ended because of block within the antegrade pathway (ended with a P-wave), and four episodes stopped because of block within the retrograde pathway (ended without a P-wave). During the administration of isoproterenol (1 mg/min IV) all six episodes of tachycardia had LBBB but these did not end when LBBB disappeared spontaneously. When LBBB subsided, the mean tachycardia cycle interval shortened from 328.5 ± 1.4 to 264.2 ± 2.1 ms (p < 0.001). Each episode of tachycardia was then terminated by carotid sinus massage. The disappearance of LBBB in control conditions presented the retrograde and antegrade limbs of the reentrant circuit with an early impulse that stopped the tachycardia. After isoproterenol administration, the tachycardia did not end following disappearance of LBBB, thus enabling the tachycardia cycle interval to shorten by a mean of 64.3 ± 1.9 ms. This extent of tachycardia acceleration is diagnostic of the participation of a concealed, left free-wall bypass tract.
- Subjects
PAROXYSMAL tachycardia; VENTRICULAR tachycardia; BUNDLE-branch block; ATRIOVENTRICULAR node; DIAGNOSIS; PALPITATION; ISOPROTERENOL
- Publication
Pacing & Clinical Electrophysiology, 1986, Vol 9, Issue 1, p26
- ISSN
0147-8389
- Publication type
Article
- DOI
10.1111/j.1540-8159.1986.tb05358.x