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The action potential passes along the cell membrane causing the cell to contract, therefore the activity of the sinoatrial node results in a resting heart rate of roughly 60–100 beats per minute. All cardiac muscle cells are electrically linked to one another, by intercalated discs which allow the action potential to pass from one cell to the ...
Antiarrhythmic agents, also known as cardiac dysrhythmia medications, are a class of drugs that are used to suppress abnormally fast rhythms (tachycardias), such as atrial fibrillation, supraventricular tachycardia and ventricular tachycardia.
The sinoatrial node (also known as the sinuatrial node, SA node or sinus node) is an oval shaped region of special cardiac muscle in the upper back wall of the right atrium made up of cells known as pacemaker cells. The sinus node is approximately 15 mm long, 3 mm wide, and 1 mm thick, located directly below and to the side of the superior vena ...
Potassium channel blockers exhibit reverse use-dependent prolongation of the action potential duration. Reverse use dependence is the effect where the efficacy of the drug is reduced after repeated use of the tissue. [11] This contrasts with (ordinary) use dependence, where the efficacy of the drug is increased after repeated use of the tissue.
Chronotropic effects (from chrono-, meaning time, and tropos, "a turn") are those that change the heart rate.. Chronotropic drugs may change the heart rate and rhythm by affecting the electrical conduction system of the heart and the nerves that influence it, such as by changing the rhythm produced by the sinoatrial node.
The funny current is highly expressed in spontaneously active cardiac regions, such as the sinoatrial node (SAN, the natural pacemaker region), the atrioventricular node (AVN) and the Purkinje fibres of conduction tissue. The funny current is a mixed sodium–potassium current that activates upon hyperpolarization at voltages in the diastolic ...
Image of a myocardial action potential. Effective refractory period in green. In electrocardiography, during a cardiac cycle, once an action potential is initiated, there is a period of time that a new action potential cannot be initiated.
Procainamide (PCA) is a medication of the antiarrhythmic class used for the treatment of cardiac arrhythmias.It is a sodium channel blocker of cardiomyocytes; thus it is classified by the Vaughan Williams classification system as class Ia.