Table 3

Prevalence and Outcomes Related to Patients With First-Degree Heart Block and a Pacing Indication

First Author (Year) (Ref. #)Study TypePopulationNFirst-Degree AVB (ms)First-Degree AVB, n (%)Age (yrs)F/U (Months)Outcomes Related to First-Degree AVBNotes
Patients with preserved systolic function
Holmqvist et al. (2014) (60)SubanalysisMOde Selection Trial Sick Sinus Syndrome DDDR vs. VVIR1,537 (779 DDDR)>200 (baseline)375 (25)7433Increased risk of the composite death/stroke/HF hospitalization with long PR. Neither mode eliminated the negative effects of first-degree AVB
Nielsen et al. (2012) (68)SubanalysisDANPACE
DDDR vs. VVIR
1,357 (650 DDDR)PQ >180 (baseline)574 (42)7343Longer baseline PQ is associated with increased risk of AFExcluded:
PR ≥220 age <70 yrs
PR ≥260 age ≥70 yrs
Dual-chamber pacing in patients with systolic dysfunction
Kutalek et al. (2008) (80)SubanalysisDAVID trial
DDDR ICD vs. VVI ICD
LVEF 27%
12% NYHA III/IV
504>20091 (18)658DDDR is not superior to VVI pacing in patients with HF and ICD irrespective of the presence of first-degree AVBHigher % ventricular pacing in the DDDR group
Sweeney et al. (2010) (81)SubanalysisDDDR MVP vs. VVI
LVEF 35%,
19% NYHA III/IV
12% LBBB
1,031≥230156 (15)6329Increase risk of the combined all-cause mortality/HF hospitalization/HF urgent care with DDDR MVP compared with VVI when PR ≥230No difference in % ventricular pacing between groups
Patients with systolic dysfunction and indication for CRT
Olshansky et al. (2012) (5)SubanalysisCOMPANION
CRT vs. OMT
LVEF 23%
NYHA III/IV
1,520 (1,212 CRT)≥200 (baseline)792 (52)6612 OMT/16 CRTOMT group: 41% increase in risk of the composite all-cause mortality/HF hospitalization when baseline PR ≥200
Gervais et al. (2009) (4)SubanalysisCARE-HF CRT vs. OMT
LVEF 25%
NYHA III/IV
813 (409 CRT)>200 (native except 3-month CRT-paced)213 (26)6729Baseline and 3-month PR interval was associated with increased risk of the composite all-cause mortality/unplanned hospitalization
Pires et al.
(2006) (12)
SubanalysisMIRACLE CRT vs. OMT
LVEF 23%, NYHA III/IV
224Not defined69 (30)646Baseline first-degree AVB predicted nonresponse to CRT
Hsing et al. (2011) (88)SubanalysisPROSPECT-ECG Multicenter observational study426Continuous variableN/A686Baseline PR interval did not predict response to CRT
Kutyifa et al. (2014) (90)SubanalysisMADIT-CRT
CRT-D vs. ICD
QRS≥130 non-LBBB LVEF 30%
NYHA I/II
534 (327 CRT-D)≥230 (baseline)96 (18)6629ICD-group: 3-fold increase in combined all-cause mortality/HF with baseline PR ≥230. CRT-D conferred a 73% risk reduction in all-cause mortality/HF when PR ≥230 compared with ICDCurrent indication for CRT-D: QRS ≥150 non-LBBB
Kronborg et al. (2010) (13)Registry analysisDanish Pacemaker Register, 1997–2007,
CRT and CRT-D
LVEF 25%
83% NYHA III/IV
659 (225 CRT-D)>200 (baseline)208 (47)6630Entire CRT group: long PR predicted all-cause-mortality and cardiac mortality
Lee et al. (2014) (89)Retrospective analysisPatients with CRT, single center403>200 (baseline)204 (51)6753PR >200 was an independent predictor of worse response to CRT compared with ≤200, but not associated with an increase in all-cause mortality
Januszkiewicz et al. (2015) (87)Retrospective analysisPatients with CRT, single center283≥200 (baseline)125 (44)6630PR >200 was associated with an increased risk of HF hospitalization
Patients with systolic dysfunction without indication for CRT
Joshi et al. (2015) (91)SubanalysisReThinQ,
CRT vs. no-CRT,
QRS <130, LVEF 15%, NYHA III
87≥180 (baseline)41 (47)6024CRT group: increase in Vo2 max and LVEF at 6 months when PR ≥180No-CRT group not included in the analysis

Values are mean except as noted.

CRT = cardiac resynchronization therapy; CRT-D = cardiac resynchronization therapy with defibrillator; DDDR = dual-chamber pacing; ICD = intracardiac defibrillator; LBBB = left bundle branch block; MVP = managed ventricular pacing; NYHA = New York Heart Association functional class; OMT = optimal medical therapy; RV = right ventricle; VVI = right ventricular pacing; other abbreviations as in Tables 1 and 2.