The structure of atrial natriurtic peptide (ANP) and Brain natriuretic peptide (BNP) are similar and they are also similar in their actions e.g natriuresis and vasodilation. The previous studies have revealed the presence of ANP and BNP in sheep atrial extract, wherease ANP in human atrial. The aim of the present study is to investigate the comparison of hemodynamic effects of these two atrial ...

We report on a 33-year-old woman who underwent an electrophysiologic study because of a documented supraventricular tachycardia. The induced tachycardia presented with cycle length variations and an apparent ventriculo atrial (VA) dissociation on the surface ECG. Careful analysis of the activation sequence revealed the correct diagnosis of an atrioventricular nodal re-entrant tachycardia using ...

OBJECTIVE Previous studies on atrial recovery after cardioversion of atrial fibrillation have not taken into account new knowledge about the pathophysiology of transmitral and transtricuspid flow velocity patterns. It is possible to shed further light on this problem if atrioventricular inflow velocity, venous filling pattern, and atrioventricular annulus motion are recorded and interpreted tog...

Cerebral capillaries constitute the blood-brain barrier. Studies of specific receptors (neurotransmitters or hormones) located on this structure can be performed by means of radioligand-binding techniques on isolated brain microvessels. We examined on pure bovine cerebral microvessel preparations the binding of atrial natriuretic factor (ANF), using 125I-labeled ANF. Saturation and competition ...

progressive endo-epicardial dissociation, transforming the atria into an electrical double layer of dissociated waves that constantly ‘feed’ each other. Figure 1 gives a diagrammatic presentation of the double layer hypothesis. In Figure 1A and B, a rotor is compared with an epicardial breakthrough. Whereas a rotor at best can maintain itself, endo-epicardial breakthroughs act as multiplication...

The ECG (electrocardiography) shows a sinus bradycardia of 42 beats/min, a horizontal electrical heart axis and a narrow QRS complex. The second to fourth QRS complex is preceded by a P wave with a variation in the PQ time. The PQ time in the second QRS complex is 220 ms, in the third 200 ms and the fourth 140 ms. No P wave precedes the fifth QRS complex. In the sixth QRS complex, the P wave is...

• A dual transmission system was postulated in 1956 to explain certain features of A-V impulse propagation: unexpected delay in the ventricular arrival of early premature atrial impulses; changes in the electrical configuration of the delayed ventricular complexes; and atrial or ventricular echoes. A similar hypothesis was proposed by Rosenblueth, and certain complex A-V dysrhythmias in the hum...

Electrophysiologic studies were performed in a patient who had an apparently uncomplicated complete trifascicular block. His bundle recordings revealed atrioventricular dissociation with: 1) an atrial rate of 58 beats/min, 2) an idioventricular escape rate of 45 beats/min, and 3) nonparoxysmal junctional tachyeardia (His bundle rhythm) at a rate of 65-85 beats/min. The latter arrhythmia was ele...

His bundle electrograms were repeatedly recorded in two patients with complex arrhythmias. In the first case the pacemaker was located in the lower part of the left bundle-branch, retrogradely activating the His bundle. Atrial standstill was associated with this mechanism. Afterfour days, His bundle tachycardia occurred, with constant retrograde activation of the atria, and anterograde block. I...

It has been hypothesized, based on physiological evidence, that there is a greater proportion of 1-adrenergic receptors on the myocytes of the conduction system when compared with the working myocardium. The purpose of these studies was to examine f3-adrenergic receptor subtype in the conduction system of the dog by using the technique of coverslip autoradiography. Scintillation studies of ['25...