In addition, amiodarone has the potential for direct neurotoxicity, which may lead to neurodevelopmental abnormalities.523 Page et al 2015 ACC/AHA/HRS SVT Guideline e555 9.4. SVT in Older Populations 9.4.1. Acute Treatment and Ongoing Management: Recommendation The natural history of SVT is steadily changing because most patients with SVT undergo ablation at a younger age, but in general, the relative proportion of AT is higher in older popu- lations, and AVNRT is more prevalent than AVRT among patients undergoing ablation.49 Atypical atrial flutter and mac- roreentrant AT are on the rise as consequences of increasing AF ablation in this patient population, yet there are limited outcome data from RCTs for this segment of the population. Therapeutic decisions should be balanced between the over- all risks and benefits of the invasive nature of ablation versus long-term commitment to pharmacological therapy. 10. Quality-of-Life Considerations Patients with SVT may experience recurring symptoms that negatively impact their quality of life. Episodes of tachy- cardia can cause lightheadedness and syncope, which can become an obstacle to the performance of usual activities of daily living (eg, driving).72 However, there are minimal data on the effect of treatment on the quality of life for patients with SVT. In 1 study that evaluated patients with SVT who underwent ablation or received medical therapy, questionnaires such as the 36-Item Short-Form Health Survey revealed improved quality-of-life scores in several categories, including physical role functioning (perceived disability from physical limitations), general health percep- tions (perceived physical and mental health), and emotional role functioning (perceived disability from emotional limi- These improvements, measured at 1 to 5 years of follow-up, were greater in patients who underwent abla- tion than in those treated with medical therapy. 