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pharmacology
01-22-2005, 10:39 PM
A 57-year-old man is brought to the emergency room for a suspected myocardial infarction. An electrocardiogram indicates the appearance of a wide-complex ventricular tachycardia with a rate of 126 beats per minute. The physician prescribes a drug to decrease SA node automaticity, increase AV node refractoriness, and decrease AV node conduction velocity. Which of the following agents was most likely prescribed?

A. Amiodarone
B. Disopyramide
C. Lidocaine
D. Propranolol
E. Verapamil

stepanida
01-29-2005, 09:59 PM
answer d?

pharmacology
02-10-2005, 11:26 PM
A 57-year-old man is brought to the emergency room for a suspected myocardial infarction. An electrocardiogram indicates the appearance of a wide-complex ventricular tachycardia with a rate of 126 beats per minute. The physician prescribes a drug to decrease SA node automaticity, increase AV node refractoriness, and decrease AV node conduction velocity. Which of the following agents was most likely prescribed?

A. Amiodarone
B. Disopyramide
C. Lidocaine
D. Propranolol
E. Verapamil

Good job Stapandia.

The correct answer is D. The patient has a ventricular tachycardia as indicated by the electrocardiogram: the appearance of a wide-complex ventricular tachycardia with a rate of 126 beats per minute. Propranolol is a Type II antiarrhythmic agent that acts by decreasing SA node automaticity, increasing AV nodal refractoriness, and decreasing AV nodal conduction velocity. Propranolol is indicated for the treatment of ventricular tachycardias, supraventricular arrhythmias, and for slowing the ventricular rate during atrial fibrillation and atrial flutter.

Amiodarone (choice A) is a Type III antiarrhythmic that acts by prolonging the action potential duration in tissue with fast-response action potentials. Amiodarone is indicated for the treatment of refractory ventricular arrhythmias that are unresponsive to other antiarrhythmics.

Disopyramide (choice B) is a Type IA antiarrhythmic that reduces the maximal velocity of phase 0 depolarization by blocking the inward sodium current in tissue with fast-response action potentials. It also increases the action potential duration. Disopyramide is indicated for the treatment of atrial and ventricular extrasystoles and atrial and ventricular tachyarrhythmias.

Lidocaine (choice C) is a Type IB agent that attenuates phase 4 depolarization, decreases automaticity and cases a decrease in excitability and membrane responsiveness. This agent raises the ventricular fibrillation threshold as well as suppresses arrhythmias casued by abnormal automaticity. Lidocaine is used in the treatment of the acute management of ventricular arrhythmias that occur during periods of cardiac ischemia, such as cardiac surgery or secondary to an acute MI.

Verapamil (choice E), a Type IV antiarrhythmic agent, blocks calcium channels, thereby decreasing conduction velocity and increasing refractoriness in tissue with slow-response action potentials. Verapamil is indicated for the treatment of atrial fibrillation and flutter as well as other atrial tachycardias.

ceejay2005
02-03-2009, 10:26 PM
For patients who have trouble swallowing, can Amiodarone tablets be crushed and administered in apple sauce?

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