[Significance of spike potentials in the sinus nodes and atrial conduction system during interpretation of bundle-of-his electrography].

The article deals with the issues of the His bundle electrogram (HBE) analysis, using the spike potentials of the sinus node and the atrial conductive tracts for the interpretation of the HBE. The HBE and the atrium spike potentials have been recorded in 40 dogs and in 307 patients. According to our data the onset of the A-wave on the IcECG begins in some msec earlier than the onset of the P-wave on the standard ECG leads. The spike potentials of the sinus node have been recorded directly at the sinus node area, the onset of which begins in 20-40 msec earlier than the onset of the P-wave. By our data the atrial A-wave recorded from the right atrium on the IcECG consists of the slow wave showing summary effect of the atrium depolarization and the three spikes (A1, A2, A3). They are recorded at the beginning (A1) middle (A2) and the end (A3) of the P-wave and reflect the quick impulse spread through the atrium conductive tracts. The moment of the impulse coming to the AV nodes is reflected by the atrial spike A2. The time of the impulse spread from the sinus node to the AV node shows exactly the interval from the onset of the spike potential of the sinus node till the spike A2. The interval from the spike A2 to the H-potential (A2-H) shows the impulse spread time through the AV node. The recording of the HBE and the atrium spike potentials was performed by means of the microcatheter of own construction (with the unipolar electrodes, external diameter of which does not exceed 1 mm) after our method of the heart microcatheterization through the subclavian vein.