Sinus Node Dysfunction Unmasked during Dobutamine Stress Echocardiography

Abstract

Sinus bradycardia and associated isorhythmic AV dissociation may be seen during dobutamine stress echocardiography. This phenomenon is usually considered a benign peri-procedural event and is thought to be secondary to the Bezold-Jarisch reflex, with profound heart rate decrease secondary to a marked increased in vagal efferent discharge. To the best of our knowledge, dobutamine stress echocardiography unmasking clinically relevant sinus node dysfunction has never been reported. We report a case of a 50-year-old man presenting with chest pain and a history of syncope, who had worsening sinus bradycardia with isorhythmic AV dissociation during dobutamine stress echocardiography. An invasive electrophysiological study revealed marked sinus node dysfunction. The patient was referred for the insertion of a permanent pacemaker for sinus node dysfunction, chronotropic incompetence and symptomatic bradycardia. Dobutamine-associated bradycardia may not always be a benign peri-procedural physiologic effect, as in this case it may unmask clinically significant sinus node dysfunction.

Paradoxical sinus deceleration during dobutamine stress echocardiography: case series and review of the literature

“…Again, the coronary angiography revealed normal coronary anatomy, while invasive electrophysiological study revealed marked sinus node dysfunction with indication for a permanent pacemaker implantation. 9 Finally, in two other cases, reports of women aged 48 11 and 60 years, 12 experiencing severe DSE-induced PSD, the coronary angiography was normal.…”

“…Other published case reports did not describe an association between DSE-induced PSD and CAD either. 6 , 9 , 11 , 12 It is plausible that the higher proportion of CAD among PSD cases in the Attenhofer et al . study 4 reflects a higher level of baseline risk (i.e.…”