Ajmaline Challenge To Unmask Infrahisian Disease In Patients With Recurrent And Unexplained Syncope, Preserved Ejection Fraction, With Or Without Conduction Abnormalities On Surface ECG.

Pharmacological challenge with class I antiarrhythmic drug is a recommended diagnostic test in patients with unexplained syncope only in the presence of bundle branch block, when non-invasive tests have failed to make the diagnosis. Its role in patients with minor or no conduction disturbances on 12-leads ECG has not been evaluated yet. It is also not clear which are the values of His-Ventricular interval to be considered diagnostic.

[Complete atrioventricular block as the first clinical manifestation of a tick bite (Lyme disease)].

A 52-year-old male patient presented to the emergency department because of malaise and frequent dizziness. The ECG revealed high-grade atrioventricular block that required placement of a temporary pacemaker. There were no other abnormalities in physical and echocardiographic examination, and coronary angiography excluded the presence of coronary artery disease.