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[Bundle-branch reentry ventricular tachycardia induced by sinus beat]
T Morgera1, M Zecchin, F Camerini
1Divisione e Cattedra Di Cardiologia, Ospedale Maggiore e Università, Trieste.
Giornale Italiano Di Cardiologia
|November 1, 1996
Summary
A patient experienced spontaneous bundle branch reentry ventricular tachycardia after aortic valve surgery. This suggests concealed conduction changes, not intramyocardial delay, may trigger such events.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Surgery
Background:
- Bundle branch reentry ventricular tachycardia (BBRVT) is a rare arrhythmia.
- Aortic valve regurgitation can necessitate surgical intervention, potentially impacting cardiac electrophysiology.
- Post-operative syncope and bradycardia-dependent left bundle branch block (LBBB) can indicate underlying electrical instability.
Observation:
- A 50-year-old male developed recurrent syncope and LBBB following aortic valve regurgitation surgery.
- Spontaneous BBRVT with LBBB morphology was recorded, triggered by a long sinus cycle.
- Premature ventricular stimulation easily induced BBRVT, but signal-averaged ECG showed no significant intramyocardial delay.
Findings:
- The study identified a spontaneous episode of BBRVT in a post-aortic valve surgery patient.
- Bradycardia-dependent LBBB and a prolonged HV interval (70 ms) were noted.
- The disappearance of concealed anterograde conduction in the left bundle branch was hypothesized as the trigger for spontaneous BBRVT.
Implications:
- This case highlights a potential mechanism for BBRVT post-cardiac surgery, involving concealed conduction rather than intramyocardial delay.
- Negative signal-averaged ECG findings challenge the necessity of intramyocardial delay for BBRVT.
- Understanding these triggers is crucial for managing arrhythmias after valve surgery.