Background: There is sparse research on the contemporary management of stable monomorphic ventricular tachycardia (VT). Which interventions are selected and how effective they are in the real-world setting is unknown. We describe the variation and effectiveness of stable VT management.
Methods: This interim analysis of a retrospective cohort study used structured manual chart review of all treated adults with ED presentations for prolonged (>2 min) monomorphic VT in 21 community EDs from 01/2010 through 12/2017 (we have reviewed to date 36% of the cohort). We defined monomorphic VT as a regular wide-complex tachycardia (WCT) with QRS >120 ms and rate >120 beats/min. We excluded unstable patients, that is, those with an abnormal level of consciousness, dyspnea at rest, severe anginal symptoms, or physician documentation of instability. We also excluded patients whose WCT was diagnosed as supraventricular. We report the incidence of treatments, successful termination (defined as sustained VT resolution of >30 min), ED cardiac arrest, and death.
Results: We analyzed 115 eligible ED presentations from 105 patients. Mean age was 68.6 years and 25.7% were female: 34 (32.4%) had an automated internal cardioverter defibrillator (AICD), 64 (61.0%) had congestive heart failure, and 30 (28.6%) were taking chronic antiarrhythmic medications. WCT was evaluated with adenosine in 14 (12.2%) cases. Initial VT treatments were amiodarone (n=60; 56.1%), external direct-current cardioversion [DCC] (n=25; 23.4%), lidocaine (n=9; 8.4%), firing of AICD (n=5; 4.7%), procainamide (n=3; 2.8%), and other treatments (n=5; 4.6%). Initial treatment success was as follows: amiodarone (41.7%), DCC (72.0%), lidocaine (44.4%), AICD (20.0%), procainamide (66.7%), and other treatments (16.7%). Overall, 74 presentations (69.2%) required multiple treatments. Six patients had cardiac arrest, 5 of whom were admitted to the ICU and one died in the ED. At the time of hospitalization, 10 presentations (8.7%) had continued stable VT.
Conclusion: ED physicians use a variety of treatments for stable monomorphic VT with differing rates of success. Amiodarone is the most common treatment, but may be less effective than DCC. Because initial treatments are often ineffective, most patients require multiple interventions. Opportunities exist for improvements in care.