[Effect of potassium chloride on myocardial stimulation threshold and correlated electrophysiologic parameters...

The influence of KCl on different electrophysiologic parameters and myocardial stimulation threshold (MST) are considered in 9 patients with cardiac pacemaker. Reduction of MST during the diastolic period and the supernormal phase of excitability (SNP), depression of automaticity and slight bradycardia have been observed. The Authors, on the basis of kaliemia values and electrophysiologic parameters, emphasize the improvement of myocardial responsiveness when kaliemia does not exceed 6.5 mEq/l. The electrophysiologic effects of KCl are compared with those obtained in vitro on the transmembrane potential. Therapeutic effects for the treatment of arrhythmias and exit block in patients with cardiac pacemakers are considered.