Onsite QTc Interval Screening for Patients in Methadone Maintenance Treatment

To improve the electrocardiogram screening process and early detection of patients at high risk for cardiac arrhythmias, the authors created a model in their clinic where they provided an onsite electrocardiogram screening that might be feasible and practical. The authors then performed a retrospective chart review to access the efficacy and feasibility of their new onsite procedure in identifying methadone maintained patients at high risk for cardiac arrhythmias. Records from all patients who are currently or had previously been maintained on methadone in the methadone maintenance program at the Atlanta VA Medical Center between 2002 and 2009 were evaluated. Of the 140 patients treated at the clinic between 2002 and 2009, 85 were excluded from the study because they had been treated as guests (had been in treatment in other clinics but received methadone dosing temporarily from our clinic), were treated in the clinic for less than 6 months, or dropped out of treatment. Thus, 55 patient charts were selected for review. Most patients (95%) received baseline and annual electrocardiogram screening. The average baseline QTc was (417 +/- 30) and most recent QTc (442 +/- 25). This QTc prolongation from baseline showed statistical significance (P < .0001). Sixty-seven percent of patients had statistically significant QTc prolongation from baseline but was less than 450 ms (mean: 428 +/- 16, P = .008). Twenty-seven percent of patients had statistically significant QTc prolongation from baseline of more 450 ms but was less than 500 ms (mean: 460 +/- 8, P < .0001). Six percent of patients had statistically significant QTc prolongation from baseline of more 500 ms (mean: 503 +/- 1.15, P = .027). Recent cocaine use was the only individual variable that showed statistically significant correlation with QTc prolongation (F = 6.98, P = .01). The authors demonstrated in this study that providing an onsite electrocardiogram screening with a focus on patient education and limiting the referral to specialty care for patients at high risk for cardiac arrhythmias could be practical and feasible.