Week 8 Part 2

Atrial Fibrillation (AFib)

  • Overview

    • Most common dysrhythmia globally.

    • Affects approximately 2.7 to 6 million people in the U.S.

    • Incidence increases with age.

  • Risk Factors

    • Hypertension, previous strokes, Transient Ischemic Attacks (TIA), and thromboembolic events.

    • Increases risk for complications such as pulmonary embolisms and venous thromboembolic events (VTE).

  • Atrial Rate

    • The atrial rate can range from 200 to 600 beats per minute.

Pathophysiology of AFib

  • Regular rhythm differs from AFib:

    • In a normal rhythm, the sinus node fires in a structured manner, leading to coordinated contractions of the atria and ventricles.

    • In AFib, the atria exhibit chaotic electrical activity, preventing effective contraction and leading to irregular ventricular firing.

  • Consequences

    • Blood can pool around the valves due to ineffective atrial contractions, increasing the risk of clot formation.

Medications and Treatments

  • Anticoagulants

    • Eliquis (apixaban) as a direct oral anticoagulant (DOAC).

    • Warfarin (Coumadin) also used but requires INR monitoring to ensure therapeutic levels.

  • Assessment and Symptoms

    • Patients might be asymptomatic or present with irregular heartbeats.

    • Poor perfusion and decreased cardiac output can lead to symptoms like:

      • Shortness of breath

      • Weakness

      • Palpitations

      • Chest discomfort

      • Hypotension

Treatment Strategies

  • Rate Control

    • Control ventricular response using calcium channel blockers (e.g., diltiazem) or beta blockers.

    • For rapid AFib, cardioversion can be required.

  • Long-term Management

    • Patients may remain on anticoagulants if unable to restore normal sinus rhythm.

    • Monitoring is essential, especially post-cardioversion, due to risk of embolization from released clots.

Ventricular Dysrhythmias

  • Premature Ventricular Complexes (PVCs)

    • Irregular heartbeats that can occur due to irritability in the ventricles.

    • PVCs can be unifocal (originating from one site) or multifocal (from multiple sites).

    • Bigeminy, Trigeminy, and Couplets

    • Bigeminy: Every other beat is a PVC.

    • Trigeminy: Every third beat is a PVC.

    • Couplet: Two PVCs in succession.

  • Ventricular Tachycardia (V-Tach)

    • Defined as three or more consecutive PVCs; may lead to reduced cardiac output.

    • Management: Immediate defibrillation is necessary if the patient is unstable or unresponsive.

  • Ventricular Fibrillation (V-Fib)

    • A lethal condition marked by ineffective quivering of the ventricles resulting in no blood flow.

    • Requires immediate CPR and defibrillation.

  • Ventricular Asystole

    • No electrical activity in the heart.

    • Patients will not have a pulse or blood pressure; only treatment is CPR until further medical help arrives.

Diagnosis and Assessment

  • Diagnostic Tests

    • Use of ECG to identify rhythm abnormalities.

    • Assess for symptoms such as hypotension, altered mental status, or respiratory distress related to poor perfusion.

  • Regular Monitoring

    • Patients in AFib or suspected to be AFib should be placed on telemetry to monitor heart rhythm continuously.

Lifestyle Modifications

  • Stress management, regular exercise, and a balanced diet are key elements in managing hypertension, dysrhythmias, and overall cardiac health.

  • Dietary Consideration

    • Consistent intake of Vitamin K (if on Warfarin) is crucial.

    • DASH diet recommended for those with hypertension.

Summary

  • AFib is a prevalent dysrhythmia with notable complications if left untreated.

  • Effective management involves a combination of medications, monitoring, and lifestyle adjustments to minimize risks.