6
Definitions
Table 1. Definitions
Term Definition
Substantial
right
ventricular
pacing (RVP)
Chronic RVP may result in pacing-induced cardiomyopathy in a
subset of patients. Substantial RVP may be defined as RVP that is
documented to or is anticipated to exceed 40%. However, some
observational studies have indicated that RVP exceeding 20% can also
have detrimental consequences. It is acknowledged that the burden
of RVP may not be accurately predictable prior to implantation and
that these data are based on percentages that have been reported in
patients with implanted devices. For the purposes of this document,
substantial RVP refers to anticipated or actual pacing ≥20%–40%,
and less than substantial refers to anticipated or actual pacing
<20%–40%. Substantial RVP may occur due to second- or third-degree
atrioventricular block or to first-degree atrioventricular block with very
prolonged PR intervals.
Response to
CRT/CPP
CRT "response" has been variously defined in different studies,
without an actual consensus on what constitutes response. Response
to CRT may be defined using multiple criteria (see Table 2) in terms
of improvement of clinical conditions. e terms CRT "stabilizer" or
"non-progressor" have evolved to include patients who may not derive
significant reverse remodeling from CRT but seem to realize a blunting
of the natural downhill progression of HF. e terms "favorable
responder," which includes the CRT stabilizer or non-progressor, and
"unfavorable responder" have been proposed to account for this. No
specific response criteria have yet been postulated for other types of
CPP. However, it is reasonable to apply the criteria above for all forms
of CPP.
(cont'd)
