Short QT Syndrome Recommendations for Short QT Syndrome References that support the recommendations are summarized in Online Data Supplement 44. COR LOE Recommendations I B-NR In asymptomatic patients with a short QTc interval, observation without treatment is I B-NR In patients with short QT syndrome who have a cardiac arrest or sustained VA, an ICD is recommended if meaningful survival greater than 1 year IIa C-LD In patients with short QT syndrome and recurrent sustained VA, treatment with quinidine can be useful.S7.9.1.5-3,S7.9.1.5-5,S7.9.1.5-6 IIa C-LD In patients with short QT syndrome and VT/ VF storm, isoproterenol infusion can be IIb C-EO In patients with short QT syndrome, genetic testing may be considered to facilitate screening of first-degree relatives.S7.9.1.5-4 Recommendation-Specific Supportive Text 1. The prevalence of short QTc 340 ms is esti- mated to be 5 in 10000 in persons <21 years of age and is more common in An incidental finding of a short QTc 320 ms in an asymp- tomatic patient warrants monitoring and follow-up without prophylactic medication 2. Patients with cardiac arrest in the setting of short QT syndrome are known to be at increased risk for recurrent cardiac arrest.S7.9.1.5-3 S7.9.1.5-5 Approximately 18% of the small number of reported patients with short QT and implanted ICDs have experienced appropriate ICD therapies during short-term follow-up.S7.9.1.5-3,S7.9.1.5-5,S7.9.1.5-6 Therapy with quinidine may reduce the number of ICD shocks.S7.9.1.5-3,S7.9.1.5-5,S7.9.1.5-6 3. 