Search

10 patients with documented ischaemic heart disease were undergone to atrial pacing (AP) before and after administration of nifedipine. The lactate utilization (%L), ischaemic ST, angor were tested in the same conditions before and after the drug. Six patients presented negative lactate utilization (-%L) during AP before the drug and four had decreased %L during recovery. -%L was removed by the drug, in those without -%L nifedipine is able to provocate the same paradoxically. Nevertheless angor disappears n all cases while the ischaemic ST is irregulary eliminated. Paradoxical -%L after nifedipine was not assumed as result of damage of the coronary flow, as ischaemic ST and angor disappear. Probably this is the sign of byochemical block of piruvate-deydrogenasy due to the Ca++ antagonist action of nifedipine. Nifedipine favorable action was explained by the increased %L in patients with low %L during recovery time, that is expression of a increased aerobic metabolism.

Personal experience in 12 cases of atrial flutter treated with various types of atrial electrostimulation is reported. In 6 cases the sinusal rhythm was obtained immediately. In the remaining cases sinusal rhythm was also obtained with atrial fibrillation from a minimum of 2 minutes to a maximum of 48 hours.

A new technique for recording His bundle and right branch potential through the veins of the arm instead of by the femoral route is described. Recordings were carried out in 70 patients. In 10, His potential was recorded simultaneously by the femoral and brachial routes. Potentials proved to be similar as regards morphology and duration; A-V conduction time proved identical while there were slight variations in His node conduction time since the atriogram revealed varying intrinsic deflexions. It is thus possible to confirm that the recording of His potential by the brachial route offers various advantages: 1) it takes less time than the femoral route; 2) it is an excellent alternative if, for various reasons, the patient cannot be examined by the femoral route; 3) His potential can be monitored more easily because of the greater stability of the catheter and the provisional electrosimulation using the same catheter when necessary; 4) contemporaneous recording of right branch and His bundle potential is possible in association with the femoral technique with better results than those obtained using multipolar catheters; 5) it is without complications: i.e. the phlebitis, phlebothrombosis, a-v fistula, and pulmonary emboly which, however rarely, may occur when using the femoral route.

10 patients with documented heart disease were undergone to atrial pacing (AP) combined to metabolic study. A negative lactate utilization (-%L) noticed in SC (coronary synus) represents a sure proof of a subordinate pacing ischaemia. As the negative lactate utilization is absent a significative reduction of %L during AP or its persistence in recovery and a rise of L/P are further parameters of a subordinate pacing ischaemia. The Authors consider the usefulness of combining a metabolic study to AP in assessing the RC (coronary reserve).

12 patients with normal QRS either in basal condition or during atrial pacing, undergone on single premature atrial stimulation, showed several types of intraventricular aberrancies. These have been revalued with atrial premature stimulation introduced over a progressively increasing frequency of fixed atrial stimulation (extrastimulus method), sometimes after atropine. In 9 cases it was possible to eliminate completely the above mentioned aberrancies, having thus a clear reduction of the refractory periods regarding their responsible structures. In 3 cases this was not possible, owing to a less significant reduction of the refractory periods. Such fenomenon is considered as the only parameter able to identify probable initial organic facts of the His-Purkinje system.