Effect of long-term right ventricular pacing in young adults with structurally normal heart.
BACKGROUND
Right ventricular pacing increases the risk of heart failure in adults with structural heart disease. The impact of prolonged right ventricular pacing in adults without structural heart disease is not fully characterized and may depend on interactions of pacing with abnormal substrate predisposing to ventricular dysfunction.


RESULTS
We assessed the effect of right ventricular pacing in patients who underwent pacemaker implantation for isolated congenital atrioventricular block between 1964 and 2005. To assess for immunologic contribution to cardiac dysfunction, outcomes were compared between patients with (Ab(+)) and without (Ab(-)) antinuclear antibody during adulthood and an age- and sex-matched Olmsted County, Minnesota, population. Of 103 patients (mean+/-SD age, 32+/-19 years), 18 were Ab(+). Long-term survival free of new heart failure after pacemaker implantation in isolated congenital atrioventricular block patients was worse than in the matched population (P<0.001). This difference was attributable to the development of heart failure in 12 Ab(+) patients (67%; P<0.001), without differences between Ab(-) patients (2%) and the matched population (2%; P=0.7). Compared with baseline, at last follow-up, left ventricular ejection fraction did not decline in Ab(-) (53+/-9% to 57+/-12%) but decreased in Ab(+)(52+/-10% to 38+/-12%; P=0.03) patients. Survival was similar in Ab(-) patients and the Minnesota population (98%; P=0.7) but worse in Ab(+) patients (79%; P<0.01).


CONCLUSIONS
The natural history of patients with isolated congenital atrioventricular block who require pacing depends upon their antibody status. Antinuclear antibody status was a predictor for the development of heart failure and death. Long-term right ventricular pacing alone does not appear to be associated with development of heart failure, deterioration in ventricular function, or reduced survival in Ab(-) isolated congenital atrioventricular block patients.
Sagar
Sandeep
S
Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minn., USA.
Shen
Win-Kuang
WK
Asirvatham
Samuel J
SJ
Cha
Yong-Mei
YM
Espinosa
Raul E
RE
Friedman
Paul A
PA
Hodge
David O
DO
Munger
Thomas M
TM
Porter
Co-Burn J
CB
Rea
Robert F
RF
Hayes
David L
DL
Jahangir
Arshad
A
D000293:Adolescent; D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects* / Q000401:mortality*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000276:immunology / Q000401:mortality* / Q000628:therapy*; D006333:Heart Failure / Q000276:immunology / Q000401:mortality*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D011237:Predictive Value of Tests; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D013318:Stroke Volume; D016019:Survival Analysis; D018497:Ventricular Dysfunction, Right / Q000276:immunology / Q000401:mortality; D055815:Young Adult
D000974:Antibodies, Antinuclear