Premium
Alternans of the Ventricular Electrogram in Patients with an Implanted Cardioverter‐Defibrillator
Author(s) -
BAROLD S. SERGE,
KUCHER ANDREAS,
ANTOINE,
STROOBANDT ROLAND X.
Publication year - 2015
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.12758
Subject(s) - medicine , cardiology , ventricular tachycardia , implantable cardioverter defibrillator , qrs complex , t wave alternans , cardiac resynchronization therapy , catecholaminergic polymorphic ventricular tachycardia , sudden cardiac death , heart failure , ejection fraction , ryanodine receptor 2 , ryanodine receptor , calcium
Background The occurrence and significance of alternans of the ventricular electrogram (VEGM) in patients with an implanted cardioverter‐defibrillator (ICD) has been rarely reported. Objectives and Methods This report describes our observations of VEGM alternans documented in nine patients with an ICD (seven new cases and two previously published cases for comparison). Results We found seven new cases of near‐field VEGM alternans and added two of our previously reported examples. Catecholaminergic polymorphic ventricular tachycardia (CPVT) was diagnosed in one patient based on ICD recordings. Alternans occurred during ventricular tachycardia (VT) in eight patients. A fast sinus tachycardia could not be ruled out in one patient. Stable cycle length alternans was found in five patients. QRS alternans of the left ventricular (LV) electrogram (EGM) was recorded in all five patients who had a device for cardiac resynchronization therapy capable of sensing by the LV channel. These five cases exhibited corresponding alternans of the right ventricular (RV) EGM in three cases, none in one patient, and a questionable recording in another. Alternans of the far‐field (FF) VEGM occurred simultaneously with RV EGM alternans in all four patients whose device provided an FF tracing. Conclusion Ventricular alternans may be more common than realized in ICD patients with VT. The correlation of VEGM alternans with the surface electrocardiogram remains unknown. Although QRS alternans itself as an electrical pattern is generally benign, its cause may not be, as illustrated in our patient with CPVT. Furthermore, associated cycle length alternans or undersensing of the smaller alternans component may complicate ICD therapy.