Cardiac implantable electronic devices establish proper therapy for the prevention
of sudden cardiac death, significantly reducing the morbidity and mortality of patients
with arrhythmias and heart failure. It is well-known that the number of electrodes
increases the risk of complications. To preserve the benefit of atrial sensing without
the need to implant an additional lead, a single-lead ICD system with a floating atrial
dipole (DX ICD lead) has been developed. Besides all of the potential benefits, the
necessity of a reliable and stable atrial sensing via the floating dipole could be
the main concern against the use of this lead type. In the current generation of DX
devices, the specially filtered atrial signal seems to be high enough and stable over
time, which is crucial in the early detection of atrial arrhythmias, discrimination
between different forms of tachycardias in order to prevent inappropriate ICD therapy,
and achieving an optimal atrioventricular and interventricular synchrony in patients
with a two-lead CRT-DX system. The present review summarizes the benefits and potential
drawbacks of the DX ICD systems based on the available literature, furthermore, proposes
an evidence-based algorithm of ICD type selection.
