Background : Automatic diagnosis of electrocardiograms（ECG）has been widely used not only in clinical practice but in the health check-ups for more than half a century. However, the diagnostic accuracy of widely-used computer equipped electrocardiograph is not always satisfactory and therefore requires an expert’s over-read. The aim of the present study was to evaluate the current situation and factors that led to inappropriate diagnosis focused on atrial fibrillation（AF）. Method : ECGs with inappropriate computer diagnosis were evaluated carefully by members of The Task Force on Automated Diagnosis of the Electrocardiogram in Japan. Results :（1）Inappropriate diagnosis of AF was found in 54 of 50,000 health check-up ECGs（0.11％）and 51 of 272 consecutive patients（18.8％）at a cardiovascular clinic.（2）Factors of 62 under-diagnoses for AF consisted of 42（67.7％）misdiagnoses of f-wave as sinus P waves, 5（8.1％）as ectopic P waves, 8（12.9％）as atrial flutters and 7（11.3％）of no atrial excitations.（3）Factors of 83 over-diagnoses for AF consisted of 38（45.8％）that missed sinus P waves, 37（44.6％）that overlooked ectopic P waves, and 8（9.6％）that misdiagnosed typical flutter waves. Conclusion : Inappropriate automatic diagnosis of AF may result not only in unnecessary consultations with expert physicians due to over-diagnosis but also increased risk of cerebral infarction or heart failure due to under-diagnosis. The construction of highly accurate and reliable systems by further improving computer algorithms is urgent needly to improve automatic diagnosis of ECG.

Quinidine is known as a prophylactic agent for supraventricular tachycardia. Recently, qunidine sometimes has been used as an antiepileptic drug. To date, However, there are few reports of its use in children or reports of side effects. The case is a 2-year-old boy with epilepsy with migrating focal seizures. Various antiepileptic drugs and corpus callostomy were ineffective, and quinidine was introduced. The dose was increased while frequently confirming blood concentration. Seizures decreased as the dose increased. One year after introducing quinidine, he was hospitalized for gastrostomy, bradycardia and hypotension and required rapid administration of saline and catecholamine temporarily. Blood concentration during hypotension was within the therapeutic range, but the electrocardiogram showed marked QT prolongation and bradycardia. It is necessary to manage quinidine as an antiepileptic drug by paying attention not only to blood concentration but also to changes in electrocardiogram and hemodynamics.