Properties of the pacemaker current (If) in latent pacemaker cells isolated from cat right atrium.
نویسندگان
چکیده
منابع مشابه
Tachybradycardia in the isolated canine right atrium induced by chronic sympathetic stimulation and pacemaker current inhibition.
The mechanisms of sinoatrial node (SAN) dysfunction in patients with chronically elevated sympathetic tone and reduced pacemaker current (I(f); such as heart failure) are poorly understood. We simultaneously mapped membrane potential and intracellular Ca(2+) in the Langendorff-perfused canine right atrium (RA). Blockade of either I(f) (ZD-7288) or sarcoplasmic reticulum Ca(2+) release (ryanodin...
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Mammalian sinoatrial node (SAN) cells, the natural pacemaker cells of the heart, have an action potential characterized by the presence of a special phase, the slow diastolic (pacemaker) depolarization (phase 4), which drives pacemaker activity and has therefore attracted the interest of generations of cardiac physiologists. What is the basis of the pacemaker depolarization? Here the features o...
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A typical feature of sinoatrial (SA) nodal pacemaker cells is the presence of an ionic current that activates upon hyperpolarization. The contribution of this hyperpolarization-activated current, If, which is also known as the ‘funny current’ or ‘pacemaker current’, to the spontaneous pacemaker activity of SA nodal cells remains a matter of intense debate. We used experimentally recorded action...
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When 7 X 10~M tetraethylpyrophosphate (TEPP) was administered as constant perfusion, the results were: (1) A progressive slowing of atrial rate and subsequent block in conduction; (2) A decrease in slope of the prepotential of pacemaker fibers; (3) No significant change in membrane resting potential of sinoatrial and atrial fibers, even during block in conduction; (4) An accelerated repolarizat...
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We report the case of a 65year old female patient who was urgently admitted to our institution with hemothorax after pacemaker implantation. The bichamber pacemaker had been implanted one week before admission and the active fixation lead caused perforation of the right atrial wall and penetration of the right lung. Transthoracic echocardiography demonstrated a minimal cardiac effusion but ches...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1992
ISSN: 0022-3751
DOI: 10.1113/jphysiol.1992.sp019242