PT  - JOURNAL ARTICLE
AU  - P Rizzon
AU  - M Di Biase
AU  - A Chiddo
AU  - D Mastrangelo
AU  - L Sorgente
TI  - Electrophysiological properties of intravenous metoprolol in man.
AID  - 10.1136/hrt.40.6.650
DP  - 1978 Jun 01
TA  - British Heart Journal
PG  - 650--655
VI  - 40
IP  - 6
4099  - http://heart.bmj.com/content/40/6/650.short
4100  - http://heart.bmj.com/content/40/6/650.full
SO  - Heart1978 Jun 01; 40
AB  - Electrophysiological changes produced by intravenous (0.1 mg/kg) metoprolol, a new selective beta 1-blocking agent devoid of intrinsic activity, were studied in 16 subjects with estimated normal impulse formation and conduction. The most important effects were sinus bradycardia, mild increase of sinoatrial conduction time, depression of intranodal conduction, and prolongation of AV node refractory periods. Sinus node recovery time and atrial refractory periods were unmodified. Infranodal conduction and the refractory periods of the His-Purkinje system, as well as of the bundle-branches, were unchanged. These effects are compared with those observed after intravenous propranolol, pindolol, and oxprenolol.