Abstract
The effect of lignocaine on the tension produced during isometric contraction by isolated dog and human papillary muscle, on ventricular function, on myocardial oxygen utilization and high energy phosphate stores, and on coronary blood flow was determined and compared with the effects already described for propranolol. Doses of lignocaine of or in excess of 1.7 μg per milliliter decreased the tension produced during isometric contraction by isolated papillary muscle preparations and increased the time needed to reach “peak” tension during each contraction. Doses of lignocaine below 4 mg. per kilogram or infusions of 0.5 to 1.0 mg. of lignocaine per kilogram per minute did not cause any significant change in left ventricular function as determined by left ventricular work-function studies. After 5 mg. per kilogram of lignocaine was given as a single bolus, the work-function curve was flattened at high but not significantly changed at low rates of work. High energy phosphate stores and myocardial oxygen consumption were not significantly modified when doses of lignocaine up to 5 mg. per kilogram or infusions of lignocaine at a rate of 0.5 to 1.0 mg. per kilogram per minute were used. Lignocaine caused the heart rate to slow and reduced the resistance to blood flow in the coronary circulation. The efficiency with which the left ventricle pumped blood into the circulation was not modified when lignocaine was given as a single injection or infused.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call