Similarly, additional studies from older patient cohorts have consistently shown that older patients have more comorbid medical conditions, have a higher incidence of structural heart disease or ischemic heart disease, and have more severe symptoms associated with A few studies have shown that complications may be slightly higher in older patients than in younger patients, although the overall complications are low and acceptable.530,538,539 These ablation outcome data should be balanced with the risks and benefits of pharmacological therapy when therapeutic options are reviewed with older patients. Figure 22. Acute treatment of SVT in ACHD patients. Colors correspond to Class of Recommendation in Table 1; drugs listed alphabetically. *For rhythms that break or recur spontaneously, synchronized cardioversion is not appropriate. ACHD indicates adult congenital heart disease; IV, intravenous; and SVT, supra- ventricular tachycardia. be some cost associated with unintended harm or compli- cations that result from any intervention. Furthermore, the approach toward evaluating the burden of cost in the litera- ture is based on varied perspectives (eg, individual, third party, stakeholder, societal). The small body of literature evaluating cost-effectiveness strategies in PSVT has traditionally centered on an evalua- tion of medical therapy versus catheter ablation. A rigorous cost-effectiveness Markov model was conducted in 2000 to compare radiofrequency ablation to medical management with generic metoprolol from the societal perspective.105 The estimated population consisted of patients with AVNRT (approximately 65%) and AVRT. On the basis of this simula- tion, the authors concluded that, for symptomatic patients with monthly episodes of PSVT, radiofrequency ablation was the more effective and less expensive strategy when compared with medical therapy. 