Prognostic Significance of Nonsustained Ventricular Tachycardia During Dobutamine Stress Echocardiography

Nonsustained ventricular tachycardia (NSVT) is a well-recognized side effect during dobutamine stress echocardiography (DSE). This study sought to evaluate the prognostic implications of NSVT during DSE on 1,266 consecutive dobutamine stress echocardiograms performed over 1 year. NSVT, defined as ≥3 consecutive ventricular premature beats, occurred in 65 of 1,266 patients (5.1%). There was no absolute increased risk in all-cause mortality between the NSVT and no NSVT groups (22% vs 17%, p = 0.15) during the 3-year follow-up. Survival curves generated by the Kaplan-Meier method also demonstrated no increased risk in mortality between the NSVT and no NSVT groups (p = 0.43). When only studies with negative results for inducible ischemia were taken into account, survival curves showed no significant difference in all-cause mortality (p = 0.26). Studies with negative results for inducible ischemia were also stratified according to the ejection fraction (EF). Patients without inducible ischemia and mildly reduced to normal EFs (>0.45) did not have significant differences in survival between the NSVT and no NSVT groups over the 3-year follow-up (p = 0.86). However, patients without inducible ischemia and moderately reduced EFs (0.35 to 0.45) who had NSVT during DSE had significantly reduced survival over the follow-up (p = 0.01).