Fatima’s Arrhythmic Case

Classification of arrhythmias
1. According to anatomical site
  1. Supraventricular (narrow QRS)
    1. Atrial extrasystole
      1. ECG pattern
        abnormal beat arises from the atrium before the expected sinus beat
    2. Supraventricular tachycardia
      1. cause
        Ectopic focus
      2. ECG pattern
        Rregular
        150-250 BPM
        Abnormal P wave shape
      3. treatment
        vagal maneuver
    3. Atrial flutter
      1. ECG pattern
        Saw-toothed
        Atrail rate 250-350 BPM
    4. Atrial fibrillation
      1. ECG pattern
        absent P wave
        Irregular irregular, of RR wave
  2. Ventricular (wide QRS)
    1. Ventricular tachycardia
      1. cause
        ectopic focus
      2. ECG pattern
        three or more beats of ventricular origin in succession
    2. Ventricular fibrillation
      1. Cause
        several ectopic foci in ventricles
      2. No pattern in ECG
        No pulse
      3. Most serious (cause death)
2. According to the mechanism
  1. Disturbance of impulse formation:
    1. Abnormal sinus rhythms
      1. Sinus Tachycardia
        Causes
        Physiological
        Physical exercise
        Pharmacological
        Anticholinergic drugs (atropine)
        pathological
        Thyrotoxicosis, Anaemia
        ECG pattern
        1:1 P:QRS
        Regular
        100-200 BPM
      2. Sinus Bradycardia
        Causes
        Physiological
        in athletes, at deep sleep
        Pharmacological
        Beta blockers
        pathological
        Hypothyroidism, sick sinus syndrome
        ECG pattern
        less than 60 BPM
        Regular
        1:1 P:QRS
    2. Shift of the pacemaker
  2. Disturbance of impulse conduction
    1. Atrioventricular block
      1. First Degree
        ECG pattern
        1:1 P:QRS
        Regular
        PR interval > 0.2 sec; > 5 small boxes
      2. Second Degree
        Mobitz 1
        Cause
        AV node abnormality
        ECG pattern
        Progressive increase in PR interval until one QRS is dropped
        Mobitz 2
        Cause
        bundle of His block
        ECG pattern
        normal P-R interval
        2: 1 or 3: 1 P:QRS
        = dropped a beat
      3. Third Degree
        ECG pattern
        Dissociation between P wave and QRS
    2. Bundle branch block
      1. Right
      2. Left
Pharmacological managment
1. Antiarrhythmic Drugs
  1. Class I drugs
    1. use
      1. Suppress ventricular arrhythmias
    2. mechanism
      1. Sodium channels blockers
  2. Class II drugs
    1. use
      1. inhibit AV node
    2. mechanism
      1. β-adrenoceptors blockers
    3. example
      1. Propranolol
  3. Class III drugs
    1. mechanism
      1. Prolongs refractory period
        K+ channel blocker
    2. example
      1. Amiodarone
  4. Class IV drugs
    1. mechanism
      1. Calcium channel blockers
    2. example
      1. Verapamil
  5. Class V drugs
    1. mechanism
      1. Muscarinic antagonist
    2. example
      1. Adenosine
  6. others
    1. Atropine
      1. mechanism
        Anticholinergic drug
      2. use
        Increase heart rate in bradycardia and heart blocks
    2. Digitalis
      1. use
        Inhibit AV node; treat atrial fibrillation
      2. mechanism
        inhibit Na+\K+ pump
        shorten the refractory period
2. Anticoagulant drugs
  1. Heparin
    1. Structure
      1. polysaccharides
        water-soluble
        safe at pregnancy
    2. Actions & Uses
      1. Increases the activity of antithrombin 3
        inhibit factor 5 & Thrombin (f 2)
      2. prophylaxis against deep vein thrombosis
    3. Administration
      1. Intravenously
        immediate effect
        ER, Post-operation
    4. Metabolism
      1. Heparin is metabolized in the liver by heparinase
      2. excreted in the urine
    5. Adverse effects
      1. Bleeding
  2. Warfarin
    1. Structure
      1. lipid souluble
        pass placenta
        could cause teratogenicity
    2. Action & uses
      1. inhibit Vitamin K
        Inhibit Factors 2,7,9,10
      2. for patients of Artificial Valve or Atrail fibrillation
        because congestion can lead to couglation
        whose risk for a stroke is high
    3. Administration
      1. orally
        Low therapeutic index
        100% bioavailability
    4. Adverse Effect
      1. Bleeding
      2. teratogenicity
Clinical Presentation
1. Palpitation
  1. Definition
    1. Intermittent “pounding,” sensation in the chest.
    2. During rest
  2. Etiology
    1. cardiac (43%)
  3. Cardiac causes
    1. Regular
      1. supraventricular and ventricular tachycardias
    2. Irregular
      1. atrial fibrillation
  4. other causes
    1. tobacco, caffeine, atropine, thyroxine, cocaine
2. Dizziness
  1. Causes
    1. orthostatic hypotension
    2. cardiac dysrhythmia
    3. medication effects & others
  2. Cardiac mechanism
    1. Insufficient cardiac output
      1. insufficient oxygen to the brain
Thrombosis As An Arrhythmic Complication
1. Types of Thrombus
  1. Pale Thrombus
    1. Mainly platelet
    2. Cardiac chambers or arteries
  2. Red Thrombus
    1. Fibrin,RBCs, WBCs and platelets
    2. veins
  3. Mixed Thrombus
    1. Alternating layers of platelets + ﬁbrin, RBCs
    2. In heart or aorta
Public health approach to atrial fibrillation
1. Define the problem
2. Identify risk and protective factors
  1. congestive heart failure
  2. diabetes mellitus
  3. obesity
  4. alcohol consumption
  5. hypertension
3. Develop and test prevention strategies
4. Ensure widespread adoption

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Fatima’s Arrhythmic Case

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	Created by Yaman Farid about 7 years ago