2.2 Study selection and data abstraction
The abstracts retrieved from the search were reviewed by two
investigators. Articles were included :(1) Study type:observational
study and randomized controlled study; (2)study object: patients who
need permanent pacemaker implantation; (3)clearly define the
conditions for LBBAP success; (4)The ECG characteristics and pacing
parameters of baseline and follow-up including QRS duration, capture
threshold, R-wave amplitude (perception), impedance, etc. (5)have a
clear follow-up time. Articles were excluded: (1) report the acute
response only and follow-up time of LBBAP less than 1 month;
(2)repeated data from the same research center, unable to obtain full
text or original data after contacting the author; (3)case reports,
animal studies etc.; (4)documents in languages other than Chinese and
English. The extracted data included gender, age, indication of device
implantation, number of enrolled patients, success rate of implantation,
follow-up time, QRS duration at baseline and follow-up, capture
threshold at baseline and follow-up, R-wave amplitude at baseline and
follow-up, impedance at baseline and follow-up. For continuous
variables, means, standard deviations, and sample sizes were extracted
to estimate the overall average values.