Antiarrhythmic Medications and Cardiac Arrhythmias Review

Flashcard set covering antiarrhythmic medication classes (IA, IB, IC, II, III, IV), sinus tachycardia interventions, sinus arrhythmia characteristics, and premature atrial complexes based on the lecture text.

What determines the medical management of sinus tachycardia?

It is determined by the severity of symptoms and directed at identifying and abolishing its cause.

What vagal maneuvers can be considered to interrupt sinus tachycardia?

Carotid sinus massage, gagging, bearing down against a closed glottis (as if having a bowel movement), forceful and sustained coughing, and applying a cold stimulus to the face (such as an ice-cold wet towel).

What is the treatment of choice for persistent sinus tachycardia causing hemodynamic instability when vagal maneuvers and adenosine fail?

Synchronized cardioversion (electrical current given in synchrony with the patient's own QRS complex).

What intervention may be used for persistent inappropriate sinus tachycardia unresponsive to other treatments?

Catheter ablation of the SA node.

How is POTS managed when associated with hypovolemia?

Patients may be advised to increase their fluid and sodium intake, or use salt tablets if necessary.

What is the action of Class IA antiarrhythmic medications?

Moderate depression of depolarization; prolongs repolarization. Treats and prevents atrial and ventricular arrhythmias.

Which medications belong to Class IA antiarrhythmics?

Quinidine, procainamide, and disopyramide.

What specific side effects are associated with quinidine, procainamide, and disopyramide?

Diarrhea and cinchonism with quinidine; lupuslike syndrome with procainamide; constipation and anticholinergic effects (dry mouth, urinary hesitancy) with disopyramide.

What nursing intervention regarding QRS duration applies during Class IA antiarrhythmic therapy?

Monitor QRS duration for an increase of >50% from baseline.

What laboratory value must be monitored during procainamide therapy?

N-acetyl procainamide (NAPA) laboratory values.

What is the action of Class IB antiarrhythmic medications?

Minimal depression of depolarization; shortened repolarization. Treats ventricular arrhythmias.

Which medications are classified as Class IB antiarrhythmics?

Lidocaine and mexiletine.

What nursing intervention is required regarding lidocaine dosing in older adults or patients with cardiac/liver dysfunction?

Discuss with the primary provider decreasing the lidocaine dose.

What is the action of Class IC antiarrhythmic medications?

Marked depression of depolarization; little effect on repolarization. Treats atrial and ventricular arrhythmias.

Which drugs belong to Class IC antiarrhythmics?

Flecainide and propafenone.

In which patients should Class IC antiarrhythmics be avoided?

Patients with structural heart disease (e.g., coronary artery disease and HF).

What conditions require a dose reduction for Class IC antiarrhythmics?

Renal dysfunction and strict vegetarian diets.

What is the action of Class II antiarrhythmic medications?

Decreases automaticity and conduction. Treats atrial and ventricular arrhythmias.

Which drugs are listed as Class II antiarrhythmics in Table 23-1?

Acebutolol, atenolol, bisoprolol/HCTZ, esmolol, labetalol, metoprolol, nadolol, propranolol, sotalol (also has Class III actions), and timolol.

Why must patients be cautioned against abrupt withdrawal of Class II antiarrhythmics?

To avoid tachycardia, hypertension, and myocardial ischemia.

What effect do Class II antiarrhythmics have on blood glucose monitoring in diabetic patients?

They can mask symptoms of hypoglycemia.

What is the action of Class III antiarrhythmic medications?

Prolongs repolarization.

Which medications are classified as Class III antiarrhythmics?

Amiodarone, dofetilide, dronedarone, and ibutilide.

What side effects are specifically associated with amiodarone?

Pulmonary toxicity, corneal microdeposits, photosensitivity, and potentiation of digoxin.

What diagnostic test must be obtained prior to initiating amiodarone therapy?

Baseline pulmonary function tests.

What monitoring is required when initiating dofetilide or ibutilide?

Continuous ECG monitoring.

What is the mechanism of action and indication for Class IV antiarrhythmics?

Blocks calcium channels; treats and prevents paroxysmal atrial arrhythmias.

Which medications are Class IV antiarrhythmics?

Verapamil and diltiazem.

What instruction must be given regarding sustained-release Class IV antiarrhythmics?

Do not crush sustained-release medications.

What cardiac rhythm is displayed in this ECG strip, and what is its hallmark feature during respiration?

Sinus arrhythmia; the rate usually increases with inspiration and decreases with expiration.

What are the rate, rhythm, PR interval, and P:QRS ratio criteria for sinus arrhythmia?

Ventricular and atrial rate: 60 to 100 bpm in the adult; Rhythm: Irregular; PR interval: Consistent between 0.12 and 0.20 seconds; P:QRS ratio: 1:1.

Why is sinus arrhythmia typically not treated?

Because it does not cause any significant hemodynamic effect.

Where do atrial arrhythmias originate?

From foci within the atria and not the SA node.

What is a premature atrial complex (PAC)?

A single ECG complex that occurs when an electrical impulse starts in the atrium before the next normal impulse of the sinus node.

What are potential causes of a premature atrial complex (PAC)?

Caffeine, alcohol, nicotine, stretched atrial myocardium (e.g., as in hypervolemia), anxiety, hypokalemia, and hypermetabolic states.