Interventricular mechanical dyssynchrony determines abnormal heightening of plasma N-terminal probrain natriuretic peptide level in symptomatic bradyarrhythmia patients with chronic dual-chamber vs. single-chamber atrial pacing.
OBJECTIVE
Debates about adverse effects of ventricular- vs. atrial-based pacing have never ended, especially regarding cardiovascular outcomes in common pacemaker populations.


METHODS
To investigate the contribution of right ventricular apical pacing to the left ventricular negative remodeling, we measured the inter- and intraventricular mechanical dyssynchrony by echocardiography as well as plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) level in 116 consecutive patients of symptomatic bradyarrhythmias including sinus node dysfunction (SND) in 80 and atrioventricular block in 36. Dual-chamber rate-modulated pacing (DDDR) pacemakers were implanted in 76 patients (SND, 40), and single-chamber ventricular rate-modulated pacing (AAIR) pacemakers in 40 (all SND). Clinical manifestations were retrospectively correlated.


RESULTS
After 3.5 years of pacing, DDDR pacemaker patients demonstrated higher plasma NT-proBNP concentration (503 +/- 111 pg/ml) than AAIR patients (194 +/- 42 pg/ml, p = 0.002) despite similar cardiovascular function at baseline. Multivariate regression analysis revealed that the only predictor of the highest quartile of plasma NT-proBNP, i.e. >or=386 pg/ml, was the interventricular contraction time difference (p = 0.01). Reprogramming to minimize ventricular pacing percentage in 8 patients of SND caused parallel reduction of plasma NT-proBNP.


CONCLUSIONS
Interventricular mechanical dyssynchrony, imposed mostly by right ventricular apical pacing, could lead to abnormal heightening of plasma NT-proBNP concentration after chronic DDDR pacing in common pacemaker patients with normal baseline left ventricular function.
Keelung Hospital, Department of Health, Executive Yuan, Keelung, Taiwan, ROC.
Jih-Min
JM
Lin
Ling-Ping
LP
Lai
Chia-Ti
CT
Tsai
Lung-Chun
LC
Lin
Chuen-Den
CD
Tseng
Jiunn-Lee
JL
Lin
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001919:Bradycardia / Q000097:blood* / Q000503:physiopathology / Q000628:therapy; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods*; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D012804:Sick Sinus Syndrome / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D018754:Ventricular Dysfunction / Q000000981:diagnostic imaging / Q000209:etiology*
D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain