Effects of lidocaine and propranolol on the normal and anomalous pathways in patients with preexcitation

摘要: Abstract Eleven patients with preexcitation were studied by techniques of His bundle recording and atrial pacing. The P-delta interval was used as a measure anomalous pathway conduction time P-H interval, atrioventricular (A-V) nodal time. In 4 patients, failed pacing at critical paced rate, resulting in normalization conduction. Lidocaine, 50 to 100 mg intravenously, produced depressant effect on the 6 manifested decrease rate producing failure preexcitation. Anomalous effective refractory period, measured 2 prolonged 1 after administration lidocaine. effects lidocaine normal appeared be minimal. Propranolol, 5 no apparent 8 9 patients. patient, QRS slightly decreased. period unchanged this drug. Propranolol depressed (in whose H potentials visualized equivalent rates) prolongation or block proximal H, both. An additional related depression accentuation fusion complexes. summary, conduction, whereas propranolol A-V Both drugs could affect reentrant tachycardia syndrome causing part circus pathway.