Video Experimental Relacionado
Updated: Aug 31, 2026
10:53
Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
La disfunción contráctil auricular después de la fibrilación auricular a corto plazo se reduce con verapamil pero
E Leistad1, G Aksnes, E Verburg
1Institute for Experimental Medical Research, University of Oslo, Ullevål Hospital, Norway. elizabeth.leistad@ioks.uio.no
Circulation
|May 1, 1996
Resumen
El bloqueador de los canales de calcio verapamil redujo la disfunción contráctil auricular después de la fibrilación auricular, lo que sugiere que la afluencia de calcio contribuye a esta condición. El agonista del calcio BAY K8644 empeoró la disfunción.
Área de la Ciencia:
- Cardiología Cardiología.
- Electrofisiología y electrofisiología.
- Farmacología Farmacología.
Sus antecedentes:
- La contractilidad auricular se reduce después del cese de la fibrilación auricular.
- El mecanismo de esta disfunción auricular post-fibrillación es desconocido.
- La sobrecarga de calcio intracelular por la despolarización rápida es una causa hipotética.
Objetivo del estudio:
- Para investigar el papel de la afluencia de calcio transsarcolemmal en la disfunción auricular posterior a la fibrilación.
- Examinar los efectos de los bloqueadores y agonistas de los canales de calcio en esta disfunción.
- Para determinar si la isquemia auricular contribuye a la disfunción observada.
Principales métodos:
- Se estudiaron cerdos de pecho abierto con fibrilación auricular inducida.
- La contractilidad auricular se midió mediante el acortamiento del diámetro auricular izquierdo.
- Verapamil (antagonista del calcio) o BAY K8644 (agonista del calcio) fue administrado antes del segundo período de fibrilación.
Principales resultados:
- El verapamil redujo el grado y la duración de la disfunción contráctil auricular post-fibrillación.
- BAY K8644 aumento de la disfunción contráctil auricular después de la fibrilación.
- Los niveles de fosfato de creatina en el tejido auricular disminuyeron ligeramente; el ATP y el lactato se mantuvieron sin cambios, lo que indica que no hubo isquemia significativa.
Conclusiones:
- La afluencia de calcio transsarcolemal contribuye a la disfunción contráctil auricular después de la fibrilación auricular.
- El antagonismo de los canales de calcio (verapamil) mejora esta disfunción.
- El agonismo de los canales de calcio (BAY K8644) agrava la disfunción contráctil auricular posterior a la fibrilación.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:22Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class I antiarrhythmic drugs are used to treat various types of arrhythmias or irregular heart rhythms. These drugs block the sodium (Na+) channels in the cardiac cells, thereby affecting the movement of electrical impulses across the heart. Class I antiarrhythmic drugs are divided into three subgroups: Class IA, Class IB, and Class IC, each with distinct mechanisms of action and effects on the heart.
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
01:12Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of the heart's...
01:20Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
01:29Disturbances in Heart Rhythm
Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias.
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
01:25Dysrhythmias VI: Management of Dysrhythmias
Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the...
01:25ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an...