A patient with arrhythmogenic right ventricular cardiomyopathy/dysplasia, implanted with a dual-chamber implantable cardioverter-defibrillator programmed in DDD mode, showed an unexpected ventricular sensing dysfunction: despite a very long (320 ms) programmed atrioventricular (AV) interval, ventricular stimuli were delivered in the ST segment after each spontaneous conducted QRS complex. This suggested the presence of ventricular undersensing. When, however, the system was programmed in VVI mode, spontaneous QRS complexes were normally sensed, although electrogram (ECM) analysis revealed that ventricular sensing occurred 160 ms after the beginning of QRS complex. A new ventricular lead was then implanted in the outflow tract of the right ventricle, resulting in normal ventricular sensing function. At the time of intervention, the amplitude of the spontaneous ventricular signal recorded from the old ventricular lead was 2.8 mV. In this patient, no true undersensing occurred although ventricular stimuli were delivered 140 ms after the beginning of spontaneous QRS complexes when the system was in DDD mode: the cause of the apparent pacemaker malfunction was the extremely prolonged ventricular depolarization. Due to fibrofatty muscle replacement, the depolarization wave-front reached the ventricular muscle surrounding the pacemaker lead with such a delay that at the end of the programmed sensed AV interval (320 ms) the ventricular EGM had not yet attained the sensing threshold. This apparent undersensing should, thus, be defined as "late sensing." (PACE 2009; 32:677-679)

Late sensing due to extremely delayed right ventricular activation in arrhythmogenic right ventricular cardiomyopathy.

BRAMANTI, Oreste;MELLUSO, Concetta;LUCA', fabiana;ORETO, LILIA;ORETO, Giuseppe
2009-01-01

Abstract

A patient with arrhythmogenic right ventricular cardiomyopathy/dysplasia, implanted with a dual-chamber implantable cardioverter-defibrillator programmed in DDD mode, showed an unexpected ventricular sensing dysfunction: despite a very long (320 ms) programmed atrioventricular (AV) interval, ventricular stimuli were delivered in the ST segment after each spontaneous conducted QRS complex. This suggested the presence of ventricular undersensing. When, however, the system was programmed in VVI mode, spontaneous QRS complexes were normally sensed, although electrogram (ECM) analysis revealed that ventricular sensing occurred 160 ms after the beginning of QRS complex. A new ventricular lead was then implanted in the outflow tract of the right ventricle, resulting in normal ventricular sensing function. At the time of intervention, the amplitude of the spontaneous ventricular signal recorded from the old ventricular lead was 2.8 mV. In this patient, no true undersensing occurred although ventricular stimuli were delivered 140 ms after the beginning of spontaneous QRS complexes when the system was in DDD mode: the cause of the apparent pacemaker malfunction was the extremely prolonged ventricular depolarization. Due to fibrofatty muscle replacement, the depolarization wave-front reached the ventricular muscle surrounding the pacemaker lead with such a delay that at the end of the programmed sensed AV interval (320 ms) the ventricular EGM had not yet attained the sensing threshold. This apparent undersensing should, thus, be defined as "late sensing." (PACE 2009; 32:677-679)
2009
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11570/1953670
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 1
social impact