Potentials recorded at various sites in the atrioventricular (A-V) conduction system indicate that conduction is continuously electrical in nature and involves no synapse-like (i.e., chemical) conduction. The region between atrium and atrioventricular node has the slowest conduction velocity (.05 M./see.) and lowest safety factor. Conduction through the A-V node is at about .12 M./sec. Results ...

Electrophysiological studies with atrial extrastimulus technique suggested the presence of dual atrioventricular (A-V) nodal pathways in a patient with hypothyroidism, as evidenced by a sudden increase of H1-H2 intervals at critical A1-A2 coupling intervals. Following the atrial extrastimulus (A2), a third impulse (A3) occurred spontaneously. During slow pathway conduction of A2, and A3, appear...

OBJECTIVES To evaluate serial central motor conduction time in the Miller Fisher syndrome. METHOD Three patients with classic Miller Fisher syndrome were evaluated clinically. They had serial central motor conduction times measured with transcranial magnetic stimulation and nerve conduction studies. Motor evoked potentials were recorded from the first dorsal interossei and abductor hallucis m...

Electrophysiological studies with atrial extrastimulus technique suggested the presence of dual atrioventricular (A-V) nodal pathways in a patient with hypothyroidism, as evidenced by a sudden increase of H,-H2 intervals at critical A,-A2 coupling intervals. Following the atrial extrastimulus (A2), a third impulse (A3) occurred spontaneously. During slow pathway conduction of A2, an A3, appeari...

BACKGROUND Bachmann's bundle (BB) is considered to be the main route of interatrial conduction and to play a role in development of atrial fibrillation (AF). The goals of this study are to characterize the presence of conduction disorders in BB during sinus rhythm and to study their relation with AF. METHODS AND RESULTS High-resolution epicardial mapping (192 unipolar electrodes, interelectro...

Investigation to evaluate axial wall heat conduction has been conducted for heat transfer in a laminar flow circular tube with two classical thermal boundary conditions at the outside wall. The tube ends are either adiabatic or with heat losses. The simulation is three-dimensional with various wall materials, wall thicknesses and tube lengths. A wide range of Peclet number from 7 to 14,000 is c...

Conduction velocity from spinal cord to axilla (estimated using the F wave) has been compared with conduction velocity from axilla to wrist (measured in the conventional manner) in the motor fibres of the ulnar nerve in 17 controls subjects and in 11 patients with the Guillain-Barré syndrome (GBS). In the patients with GBS the conduction velocity was, in general reduced to a similar extent in b...

Adenosine and related compounds can produce atrioventricular (A-V) conduction block. Similar conduction disturbances are observed in myocardial hypoxia. To investigate the possibility that adenosine might be causally involved in hypoxic conduction disturbances, we measured A-V conduction times, subdivided into atrial-to-His bundle (A-H) and His bundle-to-ventricular (H-V) intervals, with extrac...

BACKGROUND There is a significant variability observed in the conduction properties of the atrioventricular node. In a subset of hearts, impulse transmission tends to fall into two distinct conduction regions, termed the slow and fast pathway, and a further subset are capable of dual conduction of a single input stimulus, termed double firing. METHODS AND RESULTS In this article, we closely c...

BACKGROUND AND OBJECTIVES Local wide split double potentials are used as a parameter to determine complete conduction block during cavotricuspid isthmus ablation in patients with isthmus dependent atrial flutter. However, delayed slow conduction in that region can sometimes be very difficult to differentiate from complete block. Flutter cycle length (FCL) can be used to confirm isthmus conducti...