Key result
Pharmacological testing with atropine in a patient with concealed sinus node dysfunction paradoxically induced an accelerated junctional rhythm and resolved ventricular ectopy.
Case Report (n=1)
Atropine testing in a patient with concealed sinus node dysfunction can paradoxically induce an accelerated junctional rhythm while suppressing bradycardia-induced ventricular hyperexcitability.
Answers are grounded in this paper and cite their sources.
Paradoxical atropine response in concealed SND should not change practice; leaves open diagnostic utility pending larger series.
A 78-year-old male patient presented with repetitive fainting episodes. His electrocardiogram showed sinus rhythm with persistent ventricular bigeminy. Concealed sinus node dysfunction (SND) with consecutive bradycardia-induced ventricular hyperexcitability was suspected. Pharmacological testing with atropine resulted in accelerated junctional rhythm along with nearly total disappearance of the ventricular ectopy. The diagnosis of SND was retained, a dual chamber pacemaker was implanted, and consequently, ventricular hyperexcitability disappeared. The junctional rhythm was a paradoxical effect of atropine, and many explanations were provided. Discussion was made accordingly taking into account relevant data from the literature.
No takes yet. Share an insight, caveat, or question.
Karam et al. (2014) conducted a case report in Concealed sinus node dysfunction (n=1). Atropine was evaluated on Rhythm response and ventricular ectopy. Pharmacological testing with atropine in a patient with concealed sinus node dysfunction paradoxically induced an accelerated junctional rhythm and resolved ventricular ectopy.
Synapse has enriched 10 related papers. Consider them for comparative context: