This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Amar, D. Articles by Nguyen, H. Search for Related Content PubMed PubMed Citation Articles by Amar, D. Articles by Nguyen, H.

---

CARDIOVASCULAR ANESTHESIA

The Effects of Advanced Age on the Incidence of Supraventricular Arrhythmias After Pneumonectomy in Dogs

David Amar, MD^*, Paul M. Heerdt, MD PhD^*, Robert J. Korst, MD, Hao Zhang, MD^*, and Hai Nguyen, VDM

Departments of *Anesthesiology and Critical Care Medicine, Surgery, and Veterinary Medicine, Memorial Sloan-Kettering Cancer Center; and Weill Medical College of Cornell University, New York, New York

Address correspondence and reprint requests to David Amar, MD, Memorial Sloan Kettering Cancer Center, 1275 York Ave., M304, New York, NY 10021. Address e-mail to amard{at}mskcc.org

Because advanced age is the strongest independent risk factor for the development of supraventricular arrhythmias after lung resection, we compared the incidence and premorbid events of supraventricular arrhythmias after pneumonectomy in young and elderly dogs with the aim of better understanding potential age-related arrhythmogenic mechanisms. Right pneumonectomy was performed in 15 male mongrel dogs ("old" 8 yr [n = 8], "young" <4 yr [n = 7]) and the electrocardiogram continuously recorded by an implantable telemetry system for 1 wk before euthanizing. After surgery, 7 of 8 older animals (88%) developed a total of 23 episodes of sustained (>30 s) paroxysmal supraventricular tachycardia (SVT), compared with 0 of 7 (0%) young dogs, P = 0.0014. Analysis of heart rate over the 60 min preceding the onset of SVT revealed a progressive increase in sinus rhythm beginning 15 min before the arrhythmia. Comparison of the heart rate and rhythm obtained in younger animals from the corresponding postoperative hour demonstrated that although older animals developed more atrial (P = 0.03) and ventricular premature contractions (P = 0.056) and episodes of nonsustained ventricular tachycardia (P = 0.01), heart rate was similar for both groups until the increase in elderly dogs preceding the onset of SVT. Histologic examination of the atria showed interstitial fibrosis in old but not young animals. In addition, 4 of 8 (50%) elderly animals exhibited an inflammatory response within the atria consistent with acute myo- and epicarditis. We conclude that elderly dogs have an increased supraventricular arrhythmogenic potential within the first week after pneumonectomy than younger animals, perhaps because of increased atrial fibrosis and inflammation. Heart rate analysis before SVT onset suggests that adrenergic predominance was a probable responsible trigger.

IMPLICATIONS: In this canine pneumonectomy model, advanced age was associated with an increased incidence of supraventricular arrhythmias, perhaps because of increased atrial fibrosis and inflammation.

This article has been cited by other articles:

				D. Amar, H. Zhang, and N. Roistacher The Incidence and Outcome of Ventricular Arrhythmias After Noncardiac Thoracic Surgery Anesth. Analg., September 1, 2002; 95(3): 537 - 543. [Abstract] [Full Text] [PDF]