[Diagnosis of total block in the bundle of His with rhythm of idioventricular substitution].

His bundle (HB) recording does not allow the recognition of third degree intrahisian block in patients with complete atrio-ventricular block (AVB) associated with idioventricular rhythm, due to the absence of pacemaker activation in the distal HB region. We have observed fixed retrograde distal HB activation in the standard HB recording of a patient with complete AVB and ventricular rhythm at a rate of 28/min. Retrograde distal HB activation (h'r) did not disappear during apical right ventricular pacing, in association with the complete absence of retrograde nodal conduction: concealed retroconduction into the proximal HB did not allow the recording of anterograde hisian deflection when the interval between h'r deflection and the subsequent sinus atriogram was shorter than 200 msec.

[Paradoxical effect of nifedipine. A case report].

The provocation of ischaemic cardiac pain by nifedipine, as side effect, is claimed to be rare. We describe one patient treated with nifedipine in whom this effect was accompanied by electrocardiographic changes that suggested subepicardial ischaemia. We believe that these changes were the consequence of a nifedipine-induced coronary spasm.