Effect of intravenous digitoxin on inotropy, haemodynamics and P-Q interval in ischaemic heart disease.
The haemodynamic and electrophysiologic responses to rapid intravenous injection of digitoxin (0.6 mg over 5 min) were measured in 6 patients with chronic coronary heart disease without clinical heart failure. Two minutes after end of injection peripheral resistance increased and stroke volume fell, while peak dP/dt in the right ventricle showed minimal increase. AV nodal conduction velocity decreased markedly. Thereafter, the peripheral resistance remained unchanged, stroke volume and peak dP/dt in the right ventricle increased slightly, while AV conduction remained stable. In 2 control patients stable values were found during 60 min. We conclude that digitoxin given intravenously as a single bolus injection induces an abrupt slight increase in peripheral resistance. Thereafter, a gradual increase in inotropy is found. The effect on the AV node appears rapidly and remains stable.
D000368:Aged; D001283:Atrioventricular Node / Q000187:drug effects; D003327:Coronary Disease / Q000188:drug therapy* / Q000503:physiopathology; D004074:Digitoxin / Q000008:administration & dosage* / Q000097:blood; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*; D013318:Stroke Volume / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D004074:Digitoxin