Loss of biventricular capture related a dysfunction of the right ventricular lead

Patient

79 years old man implanted with a triple chamber defibrillator Consulta XT CRT-D for ischemic cardiomyopathy with a wide QRS (The device was implanted 8 years ago and already replaced once); the consultation is motivated by several electrical shock received while he was working in his garden;

Trace

Plots

scattered repartition at the ventricular level (great variability of the cycles length with very short intervals);
electrical cardioversion;
short ventricular cycles ;
end of the oversensing ;

Tracing

ventricular oversensing of anarchical signals in the VT and VF zones ;
intermittent biventricular stimulation ;
spontaneous ventricular activities;
NID in the VF zone is reached ; detection of an episode of VF and charge of the capacitors;
end of charge (CE) ;
confirmation: 4 consecutive VS… The therapy is abandoned;
new detection of a FV and new charge of the capacitors;
end of charge (very short, the capacitors had no time to discharge) ;
no confirmation for this redetected episode; immediate delivery of an electrical shock (34.3 Joules) ;
temporary interruption of the oversensing and biventricular stimulation ;
new episode of oversensing;
end of the episode;

Comments

This patient presented a fracture of the right ventricular lead. This patient was initially implanted for primary prevention in the context of a severe heart failure. He has never presented any episodes of arrhythmia during the entire follow-up. However, he presented a very significant clinical and echocardiographic improvement form the resynchronization therapy. Regarding the diagnosis of lead fracture, different options are possible. The easiest would be probably to disable the defibrillation function of the device to prevent any recurrence of inappropriate therapies while maintaining a biventricular pacing. However, this tracing shows the limits of this strategy since the oversensing also inhibits the biventricular pacing. It is likely that with the progression of the lead problem, the oversensing will increase and results in a significant drop in the percentage of biventricular pacing. A second option is to add a new defibrillation lead (this option was chosen in this patient) or right ventricular pacing lead. The management of the former broken lead is difficult. It was left in place in the patient. Indeed, its extraction is probably not justified in a patient of this age, especially if we consider the associated risk of damaging the left ventricular functional lead.

Pacing & Defibrillation

ECG

Library

News