Correspondence

Cardiac Pacing for Sinus-Node Dysfunction

N Engl J Med 2002; 347:1891-1892December 5, 2002

Article

To the Editor:

If Lamas et al. (June 13 issue)1 wished to compare dual-chamber pacing with single-chamber pacing in patients with sinus-node dysfunction, why did they not compare single-chamber right atrial pacing with dual-chamber pacing? This mode of pacing is infrequently used, but in a patient with only sinus-node dysfunction, it would have been both physiologic and less expensive. The only justification for dual-chamber pacing in these patients would be the presumption of associated atrioventricular-node dysfunction, but the associated presence of atrioventricular-node disease in these patients was not mentioned. Single-chamber atrial pacing would have eliminated the problem of the pacemaker syndrome and undoubtedly the increased frequency of atrial fibrillation that was noted with ventricular-demand pacing.

Burton T. Blackman, M.D.
6621 Moore Dr., Los Angeles, CA 90048
eblack6621@aol.com

1 References

1. 1

   Lamas GA, Lee KL, Sweeney MO, et al. Ventricular pacing or dual-chamber pacing for sinus-node dysfunction. N Engl J Med 2002;346:1854-1862
   Full Text | Web of Science | Medline

Author/Editor Response

The authors reply:

To the Editor: Dr. Blackman raises the interesting point that for patients with sinus-node dysfunction and normal atrioventricular conduction, atrial pacing alone should suffice to provide atrioventricular synchrony. Single-chamber atrial pacing is probably safe in carefully screened patients with sinus-node dysfunction. In a clinical series of 399 Danish patients with normal atrioventricular and intraventricular conduction in whom atrial pacemakers were implanted, the rate of development of atrioventricular block was 1.7 percent per year.1 In our study, however, we did not study single-chamber atrial pacing for two reasons. First, atrial pacing is rarely used in the United States. We designed the trial to compare directly the two most commonly used pacing modes in the United States — single-chamber ventricular and dual-chamber. Second, atrioventricular block was present in 21 percent of our study population, and an intraventricular block (QRS interval ≥120 msec) was present in 22 percent.2 Thus, in order to achieve the most broadly relevant results, we chose to compare dual-chamber with single-chamber ventricular pacing.

Gervasio A. Lamas, M.D.
Mount Sinai Medical Center, Miami Beach, FL 33140
glamas@msmc.com

Kerry L. Lee, Ph.D.
Duke Clinical Research Institute, Durham, NC 27705

Lee Goldman, M.D.
University of California at San Francisco, San Francisco, CA 94143

2 References

1. 1

   Kristensen L, Nielsen JC, Pedersen AK, Mortensen PT, Andersen HR. AV block and changes in pacing mode during long-term follow-up of 399 consecutive patients with sick sinus syndrome treated with an AAI/AAIR pacemaker. Pacing Clin Electrophysiol 2001;24:358-365
   CrossRef | Web of Science | Medline

2. 2

   Sweeney MO, Hellkamp AS, Greenspon AJ, et al. Baseline QRS duration ≥120 milliseconds and cumulative percent time ventricular paced predicts increased risk of heart failure, stroke and death in DDDR-paced patients in sick sinus syndrome in MOST. Pacing Clin Electrophysiol 2002;25:690-690 abstract.
   CrossRef | Web of Science

Citing Articles (1)

Citing Articles

1. 1

   Malini Govindan, Andrei Catanchin, A John Camm. (2008) The Place of Hybrid Therapies With Drugs to Supplement Nonpharmacological Therapies in Atrial Fibrillation. Journal of Cardiovascular Pharmacology 52:3, 210-221
   CrossRef