The full content of Annals is available to subscribers

Subscribe/Learn More  >
Articles |

The Role of Pacing Modality in Determining Long-Term Survival in the Sick Sinus Syndrome

Elena B. Sgarbossa, MD; Sergio L. Pinski, MD; and James D. Maloney, MD
[+] Article, Author, and Disclosure Information

From the Cleveland Clinic Foundation, Cleveland, Ohio. Requests for Reprints: Elena B. Sgarbossa, MD, Department of Cardiology, Desk F15, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195. Acknowledgments: The authors thank Lon W. Castle, MD, Bruce L. Wilkoff, MD, Victor A. Morant, MD, and Tony W. Simmons, MD, for their clinical work, which made possible the careful analysis of a large number of pacemaker implants; Richard G. Trohman, MD, for his review of the manuscript and suggestions; Marlene Goormastic, MPH, and David Miller, MS, for their collaboration in the statistical analysis of the data; and John Frater, Jr., for his cooperation in the data collection. Grant Support: In part by grants from Keith Benson Memorial Fund and DuPont Pharmaceuticals, Wilmington, Delaware.

Copyright 2004 by the American College of Physicians

Ann Intern Med. 1993;119(5):359-365. doi:10.7326/0003-4819-119-5-199309010-00002
Text Size: A A A

Objective: To determine whether the atrial-based pacing modalities (physiologic pacing) improve survival when compared with single-chamber ventricular pacing in patients with the sick sinus syndrome.

Design: Retrospective, nonrandomized study.

Setting: A tertiary care teaching hospital.

Patients: A total of 507 patients with a mean age of 66 years who received an initial pacemaker for the sick sinus syndrome between January 1980 and December 1989. Pacing modes were ventricular (22%), atrial (4%), and dual-chamber (74%).

Measurements: Total and cardiovascular mortality rates. Mean follow-up was 66 months.

Results: Independent predictors of total mortality by the Cox proportional-hazards model were 1) New York Heart Association functional class [hazard ratio =1.67/class; 95% CI, 1.31 to 2.11]; 2) age [hazard ratio = 1.62/12-year increment; CI, 1.28 to 2.05]; 3) peripheral vascular disease [hazard ratio = 2.21; CI, 1.42 to 3.42]; 4) bundle branch block [hazard ratio = 2.04; CI, 1.33 to 3.13]; 5) coronary artery disease [hazard ratio = 1.66; CI, 1.15 to 2.39]; and 6) valvular heart disease (hazard ratio = 1.71; CI, 1.08 to 2.69). The same variables were independent predictors of cardiovascular mortality, with cerebrovascular disease reaching borderline statistical significance (hazard ratio = 1.69; CI, 1.00 to 2.86). Using univariate analysis, single-chamber ventricular pacing had more than 40% increased risk for both total and cardiovascular death, but the difference was of borderline statistical significance (total mortality: P = 0.053; hazard ratio = 1.43; CI, 0.99 to 2.07; cardiovascular mortality: P = 0.15; hazard ratio = 1.41; CI, 0.87 to 2.29).

Conclusions: Because the role of the ventricular pacing mode as a long-term predictor of total and cardiovascular mortality remains inconclusive, a large, randomized study is necessary to confirm whether physiologic pacing provides a substantial reduction in mortality when compared with ventricular pacing.


Grahic Jump Location
Figure 1.
Actuarial survival in the study group compared with the expected survival for an age- and gender-matched general population.PP

Dots represent 95% confidence intervals for each year. Difference first reaches statistical significance at 72 months ( = 0.002) and continues to be significant thereafter ( = 0.005 at 10 years). The numbers beneath the graph are the numbers of paced patients with the sick sinus syndrome who were at risk at each point.

Grahic Jump Location
Grahic Jump Location
Figure 2.
Total actuarial survival for patients with physiologic pacing and ventricular pacing after adjustment for all covariates.P

The numbers beneath the graph are the numbers of patients in each group who were at risk at each point. = 0.17.

Grahic Jump Location




Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).


Submit a Comment/Letter
Submit a Comment/Letter

Summary for Patients

Clinical Slide Sets

Terms of Use

The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.


Buy Now for $32.00

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Related Articles
Topic Collections
PubMed Articles
Forgot your password?
Enter your username and email address. We'll send you a reminder to the email address on record.