His bundle electrograms were recorded and A-V junction pacing was achieved in 30 patients by a pervenous electrode catheter technic. His bundle pacing was achieved in 26, and A-V node pacing in five patients. Conduction time from atrium to the His bundle (A-H time) and His bundle to ventricular activation (H-V time) were measured. During His bundle pacing, the pacing impulse to ventricular acti...

a portion of the relative refractory period of the A-V node consistently produced atrial reentry-echoes or sustained SVT. In two patients, APDs falling within the A-V effective refractory period failed to excite the His bundle but still reentered within the A-V node and began SVT. It was noted that the various relationships between atrial and ventricular depolarizations on the surface ECG did n...

Procaine amide was given intravenously to three patients with transient ventricular fibrillation during established auriculoventricular dissociation at a time when they were free from symptoms as well as during the attacks. It was determined that this drug has a transitory slowing effect upon the auricles. It depresses rhythmicity in the auriculoventricular node, prolongs the refractory period ...

a portion of the relative refractory period of the A-V node consistently produced atrial reentry-echoes or sustained SVT. In two patients, APDs falling within the A-V effective refractory period failed to excite the His bundle but still reentered within the A-V node and began SVT. It was noted that the various relationships between atrial and ventricular depolarizations on the surface ECG did n...

SUMMARY In order to answer the question whether the atrium is a link in the pathway of ventricular reciprocation or whether the A-V node itself is the reflection point of the echo, a special stimulation program was followed in six patients in whom ventricular echo beats with stable time relations could be elicited by regular pacing of the right ventricle or by the application of appropriately t...

We examined the electrophysiological effects of dopamine on the single myocardial cells isolated from the rat and rabbit heart. Dopamine at a concentration of 1 or 10 microM did not affect the L-type Ca2+ current (ICa) or the transient outward current (ITO) in rat ventricular, rabbit atrial, ventricular, and sinoatrial node cells. It did not induce any detectable change in the action potential ...

a portion of the relative refractory period of the A-V node consistently produced atrial reentry-echoes or sustained SVT. In two patients, APDs falling within the A-V effective refractory period failed to excite the His bundle but still reentered within the A-V node and began SVT. It was noted that the various relationships between atrial and ventricular depolarizations on the surface ECG did n...

a portion of the relative refractory period of the A-V node consistently produced atrial reentry-echoes or sustained SVT. In two patients, APDs falling within the A-V effective refractory period failed to excite the His bundle but still reentered within the A-V node and began SVT. It was noted that the various relationships between atrial and ventricular depolarizations on the surface ECG did n...

a portion of the relative refractory period of the A-V node consistently produced atrial reentry-echoes or sustained SVT. In two patients, APDs falling within the A-V effective refractory period failed to excite the His bundle but still reentered within the A-V node and began SVT. It was noted that the various relationships between atrial and ventricular depolarizations on the surface ECG did n...

A 38-year-old female had felt exertional dyspnea for six months. Physical examination and laboratory data including angiotensin-converting enzyme, failed to diagnose sarcoidosis. Her chest X-ray showed cardiomegaly but no hilar lymph node enlargement. Holter ECG showed nonsustained and sustained ventricular tachycardias, monomorphic or polymorphic tachycardia. Echocardiography and contrast left...