Amar David, Heerdt Paul M, Korst Robert J, Zhang Hao, Nguyen Hai
Department of Anesthesiology and Critical Care Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Anesth Analg. 2002 May;94(5):1132-6, table of contents. doi: 10.1097/00000539-200205000-00013.
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" > or =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.
In this canine pneumonectomy model, advanced age was associated with an increased incidence of supraventricular arrhythmias, perhaps because of increased atrial fibrosis and inflammation.
由于高龄是肺切除术后发生室上性心律失常最强的独立危险因素，我们比较了年轻和老年犬肺切除术后室上性心律失常的发生率和病前情况，旨在更好地理解潜在的与年龄相关的心律失常机制。对15只雄性杂种犬进行了右肺切除术（“老年”≥8岁[n = 8]，“年轻”<4岁[n = 7]），并在安乐死之前通过植入式遥测系统连续记录心电图1周。术后，8只老年动物中有7只（88%）共发生23次持续（>30秒）阵发性室上性心动过速（SVT）发作，而7只年轻犬中无一例（0%）发生，P = 0.0014。对SVT发作前60分钟的心率分析显示，心律失常开始前15分钟窦性心律逐渐增加。比较年轻动物在相应术后时间点的心率和心律发现，尽管老年动物出现更多房性早搏（P = 0.03）和室性早搏（P = 0.056）以及非持续性室性心动过速发作（P = 0.01），但在老年犬SVT发作前心率增加之前，两组心率相似。心房组织学检查显示老年动物有间质纤维化，而年轻动物没有。此外，8只老年动物中有4只（50%）心房内出现与急性心肌和心外膜炎一致的确炎症反应。我们得出结论，老年犬在肺切除术后第一周内发生室上性心律失常的可能性比年轻动物高，可能是由于心房纤维化和炎症增加。SVT发作前的心率分析表明，肾上腺素能占优势可能是一个触发因素。
在这个犬肺切除模型中，高龄与室上性心律失常发生率增加有关，可能是由于心房纤维化和炎症增加。
