Question

what is the pathophysicology , signs and symptoms, medications, Labs and diagnosis, nursing interventions of atrial fib/flutter, PVCs, 1st degree heart block, second degree type one and third degree heart block.

Answer 1

Arterial fibrillation:Atrial fibrillation (also called AFib or AF) is a quivering or irregular heartbeat (arrhythmia) that can lead to blood clots, stroke, heart failure and other heart-related complications.

It is characterized by an irregular and often rapid heartbeat (see the first image below). The exact mechanisms by which cardiovascular risk factors predispose to AF are not understood fully but are under intense investigation. Catecholamine excess, hemodynamic stress, atrial ischemia, atrial inflammation, metabolic stress, and neurohumoral cascade activation are all purported to promote AF.

Pathophysiology:

• AF is initiated by rapid electrical activity, often arising from arrhythmogenic foci located in the muscular sleeves of pulmonary veins. The arrhythmia is maintained by multiple re-entrant wavelets. Reduced refractoriness and conduction slowing facilitate re-entry

• After a period of continuous AF, electrical remodelling occurs, further facilitating AF maintenance (AF begets AF). These changes are initially reversible if sinus rhythm is restored, but may become permanent and be associated with structural changes if fibrillation is allowed to continue

Those who do have atrial fibrillation symptoms may experience signs and symptoms such as:

• Palpitations, which are sensations of a racing, uncomfortable, irregular heartbeat or a flip-flopping in your chest
• Weakness
• Reduced ability to exercise
• Fatigue
• Lightheadedness
• Dizziness
• Shortness of breath
• Chest pain

Treatment

The treatment goals of atrial fibrillation (AF or AFib) start with a proper diagnosis through an in-depth examination from a physician. The exam usually includes questions about your history and often an EKG or ECG. Some patients may need a thorough electrophysiology study.

Medications are often prescribed to prevent and treat blood clots which can lead to a stroke. Additional drugs may be prescribed to control heart rate and rhythm in the AFib patient.

• Beta blockers. These are drugs used to slow the heart rate. Most people can function and feel better if their heart rate is controlled. Read more about beta blockers.
  • Some examples may include:
    • Atenolol
    • Bisoprolol
    • Carvedilol
    • Metoprolol
    • Nadolol
    • Propranolol
    • Timolol
• Calcium channel blockers. These medications have multiple effects on the heart. They are used to slow the heart rate in patients with AFib and to reduce the strength of the muscle cell’s contraction.
  • Some examples are:
    • Dilitiazem
    • Verapamil
• Digoxin. This medication slows the rate at which electrical currents are conducted from the atria to the ventricle.

• Sodium channel blockers which help the heart's rhythm by slowing the heart's ability to conduct electricity.
  • Examples may include:
    • Flecainide (Tambocor®)
    • Propafenone (Rythmol®)
    • Quinidine (Various)
• Potassium channel blockers help the heart’s rhythm by slowing down the electrical signals that cause AFib.
  • Examples may include:
    • Amiodarone (Cordarone® or Pacerone®)
    • Sotalol (Betapace®)
    • DofetilidPacemakers

  • SURGICAL PROCEDURE

  • A pacemaker is a small electrical device implanted in the body with wires going to the heart to regulate the heartbeat. It is implanted under the skin near the collarbone and sends out an electrical signal to keep a steady contracting rhythm in the heart.

  • Open-heart maze procedure

  • Maze heart surgery is a complex procedure in which a surgeon creates small cuts in the upper part of your heart. The cuts are then stitched together and scar tissue forms. The scars interfere with the transmission of electrical impulses that can cause AFib. Normal heartbeat is then restored.

  • NURSING INTERVENTION

  • Nursing Interventions and Rationales:

  • Obtain a 12 lead ECG

    • Used to diagnose atrial fibrillation
      
      The waves are more chaotic and random
      
      The beat is irregular
      
      You can see the atria quivering between the QRS (ventricles pumping)
      
      No discernible P waves The ventricular rate is often 110-160 bpm and the QRS complexes is usually less than 120 ms.

  • Potential rhythm control: Electrocardioversion, Ablation, Pacemaker

    • -Electrocardioversion: AKA cardioversion, is used to “reset” the heart’s electricity.
      
      The patient will be shocked on the outside of the chest wall. This treatment is used for patients who have infrequent episodes of atrial fibrillation because if the patient has it frequently, they have a high probability of the afib returning after being cardioverted.

    • Heart rate control: Beta Blockers: -Propranolol -Metoprolol -Atenolol Calcium Channel Blockers: -Diltiazem -Verapamil Cardiac Glycosides: -Digoxin

    • A heart can only sustain rapid beating for so long before it tires out. Using beta blockers, calcium channel blockers and cardiac glycosides will help control the rate of the heart beat.
      
      Beta Blockers: They block beta 1 receptors from being stimulated. Stimulation of Beta 1 causes positive inotropic (force of contraction) and chronotropic (pace of heart beat) effects. If you block beta 1 you will have decreased force of contraction and decreased heart rate.
      
      Calcium Channel Blockers: They block calcium channels… Duh. When calcium enters the cell in causes the cell to contract, thus when the channels are blocked, it decreases the production of electrical activity innately decreasing the heart rate.
      
      Cardiac Glycosides: This medication stimulates the Vagus nerve, which when stimulated slows the heart rate down. The vagus nerve is a CNS nerve that also works with the PNS- specifically the autonomic parasympathetic system… AKA rest and digest… So if this is stimulated your body will rest/slow down, thus decreased heart rate.

    • Anticoagulant Therapy: Coumadin Aspirin Lovenox Plavix Eliquis

      • Thinning the blood helps to disintegrate and break up the clot as well as increasing flow of blood. There are many options for blood thinners each with their own pro’s and con’s. The most common are listed to the left.

    • Fall education

      • Being on a blood thinner, the patient needs to be informed of their risk of bleeding out especially if they fall and hit their head.
        
        Make sure to go over environmental hazards such as good lighting and eliminating throw rugs.
        
        If a patient does fall and hit their head they need to go to the ER immediately, even if they are not experiencing any adverse effects.

    • Stroke education Use the FAST Mnemonic: F: Facial drooping A: Arm weakness S: Slurred speech T: Time to call 911

      • The risk of a blood clot forming and moving to the brain is fairly high. It is important to teach the patient and their family members the signs and symptoms of stroke.
        
        Teach the patient that if they feel confused or feel weakness on one side to call for help.

    • Cardiac enzyme monitoring: Troponin I Creatine Kinase MB

      • Initial measurement of the cardiac enzymes is important because it helps with any trending information, the sooner you get this information the better. Also getting trending results over specific periods of time is helpful.
        
        Troponin I: Is an enzyme that helps the interaction of myosin and actin in the cardiac muscle. When necrosis of the myocyte happens, the contents of the cell eventually will be released into the bloodstream.
        
        Troponin can become elevated 2-4 hours after in ischemic cardiac event and can stay elevated for up to 14 days.
        
        Creatine Kinase MB: This enzyme is found in the cardiac muscle cells and catalyses the conversion of ATP into ADP giving your cells energy to contract. When the cardiac muscle cells are damaged the enzyme is eventually released into the bloodstream.
        
        CKMB levels should be checked at admission, and then every 8 hours afterwards.