Sinus standstill following lidocaine administration.

To the Editor.— Lidocaine hydrochloride is used widely in the suppression of ventricular arrhythmias, especially during acute myocardial infarction (AMI). At the conventional therapeutic loading dose of 1 mg/kg of body weight, it is generally safe and has no inhibitory effect on sinus-node activity. 1 In this report, we describe a case of sinus standstill following administration of a bolus of intravenous lidocaine, given in the conventional dose. Report of a Case.— A 65-year-old woman was admitted to our intensive coronary care unit (ICCU) with AMI of the diaphragmatic wall. At first examination, body weight was 51 kg; BP, 100/60 mm Hg; and heart rate, 108 beats per minute. At auscultation, a 2/6 systolic murmur was heard in the mitral area, and diffuse crepitations in the pulmonary area were heard; the ECG showed sinus rhythm, incomplete left bundle-branch block, ST-segment elevation in II-III-aV L leads and negative T waves in aV