Recording of spike potentials of heart atria and His bundle using microcatheterization via subclavian vein.

The authors describe their own method of right heart microcatheterization by means of transcutaneous introduction of an original unipolar microcatheter into the left subclavian vein. The method makes possible recording of th His bundle electrogram as well as of spike potentials of the sinus node and atrial conduction pathways. His bundle electrograms were recorded in 237 subjects, of whom 72 had ischaemic heart disease and 115 suffered from other cardiopathies, 50 persons with non-cardiac diseases constituted the control group. The high diagnostic value of His bundle electrogram was confirmed, especially in appraising the degree of A-V block, differentiation between aberrant QRS complexes and ventricular extrasystolia, and in other arrhythmias. Recording of spike potentials of the sinus node, atrial conduction pathways, and His bundle, and determination of the interposed intervals allow selective assessments of the impulse propagation velocities in individual segments of heart conduction system, especially on drug administration, and offer valuable information on the genesis of various types of arrhythmias and conduction disturbances.