Diagnosis

Arrhythmia

Etiology

Cause

1. Congenital heart defects with extra pathway: Wolff-Parkinson-White

2. Automaticity: intrinsic electrical impulses inside cardiac muscle cell --> higher frequency than the SA node (ectopic focus)

3. Re-entrant arrhythmia: electrical impulse travels recurrently in a circle within the heart (supraventricular tachycardia)

4. Fibrillation: the entire heart chamber involved in multiple micro-reentry circuits --> chaotic electrical impulses (atrial fibrillation and ventricular fibrillation)

5. Conduction disturbances in the AV node or the His-Purkinje system

6. Changes in ionic current -> afterdepolarizations -> delay in repolarization (long QT syndrome and Torsade de Pointes)

Classification

1. Based on heart rate: bradyarrhythmias and tachyarrhythmia

2. According to the origin: atrial vs ventricular

3. Means of transmission: recurrent, re-entry, accessory

Tachyarrhythmia [ctu]

1. Atrial/Supraventricular Tachycardia (narrow QRS complex)

   • Atrial fibrillation

   • Atrial flutter

   • Atrial tachycardia

   • Atrial premature complex

   • Atrioventricular nodal reentrant tachycardia

   • Atrioventricular reentrant tachycardia

   • AV junctional extrasystoles

2. Ventricular Tachycardia

   • Ventricular fibrillation

   • Ventricular premature beats

   • Ventricular tachycardia

Atrial

1. Premature Atrial Contractions (supraventricular extra beats)

2. Wandering Atrial Pacemaker

3. Multifocal atrial tachycardia

4. Atrial flutter

5. Atrial fibrillation

   • New-onset

   • Paroxysmal: Self-terminating or intermittent

   • Persistent: > 7 days

   • Long-standing Persistent: Lasts for ≥ 1 year

   • Permanent: Persistent for ≥ 1 year despite treatment

Junctional arrhythmias

1. Supraventricular tachycardia

2. Atrioventricular Nodal Reentry Tachycardia (Paroxysmal Supra-ventricular Tachycardia)

3. Junctional rhythm

4. Junctional tachycardia

5. Premature junctional contraction

Ventricular

1. Premature ventricular contractions (ventricular extra beats)

2. Ventricular bigeminy/trigeminy

3. Accelerated idioventricular rhythm

4. Monomorphic Ventricular tachycardia

5. Polymorphic ventricular tachycardia

6. Ventricular fibrillation

AV blocks

1. First degree heart block, which manifests as PR prolongation

2. Second degree heart block: Type 1 (Mobitz I/Wenckebach) and Type 2 (Mobitz II)

3. Third degree heart block (complete heart block)

Sudden Arrhythmic Death Syndrome

• Myocarditis, long QT syndrome, Brugada syndrome, Catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy and arrhythmogenic right ventricular dysplasia

Risk-factors

• Old age

• Male sex

• Hypertension

• Chronic kidney disease

• Heart failure

Epidemiology

Incidence per 100.000 [ctu][qsu][sfb]

Prevalence per 100.000 [ctu][qsu][sfb]

Approach

• ECG

• 24-hour-ECG

• Echocardiography

Treatment

1. Treat underlying disease: electrolyte levels, hypertension, heart disease, sleep apnea, or thyroid disease

2. Vagal maneuvers: Coughing, gagging, Valsalva, lying down, cold towel on the face

3. Medicines:

   • Adenosine

   • Beta blocker

   • Calcium channel blocker

   • Digoxin

   • Potassium channel blocker

   • Sodium channel blocker

   • Amiodarone or procainamide

4. Cardioversion/defibrillation

5. Ablation of the accessory pathway

6. Implantable cardioverter defibrillators (ICDs)

7. Pacemakers

8. Supraventricular Tachycardia narrow complex tachycardias: [ctu]

   1. Amiodarone or procainamide

   2. Synchronized cardioversion

   3. Definitive Therapy: Ablation of the accessory pathway

9. Atrioventricular Nodal Reentrant Tachycardia: [ctu]

   1. Carotid massage/Valsalva maneuver 

   2. Adenosine

   3. Cardioversion

   4. Ablation or chronic suppressive therapy with beta-blockers and calcium channel blockers such as diltiazem/verapamil

10. Atrial fibrillation: [ctu]

    1. Rhythm control: to achieve hemodynamic stability

       • Beta-blocker

       • Cardioversion within 36 hrs of the onset or confirmed absence of thrombi (TEE)

    2. Aspirin if CHA2DS2VaSc score = 1

    3. Anticoagulation (risk of stroke) if CHA2DS2VaSc score ≥ 2

       • Heart failure with EF < 40%

       • Hypertension

       • Age > 65 years

       • Diabetes mellitus

       • History of stroke or TIA (2 points)

       • Vascular disease (peripheral vascular disease)

       • Age > 75 years

       • Female sex

11. Ventricular Tachycardia: [ctu]

    1. Implantable cardioverter-defibrillator (ICD)

    2. Sustained Ventricular Tachycardia: Lidocaine, amiodarone, procainamide, ablation

    3. Ventricular Fibrillation: cardioversion followed by amiodarone

    4. Torsades De Pointes: IV magnesium, Isoproterenol, treat hypokalemia, beta-blocker

12. Bradyarrhythmia: [ctu]

    1. Sinus Bradycardia: Isoproterenol or pacemaker if symotoms

    2. Atrioventricular Blocks:

       1st degree: No treatment

       2nd degree: Pacemaker if symptomatic Mobitz I or all Mobitz II

       3rd degree: Pacemaker

13. Sinus Node Dysfunction

    1. Symptomatic patients require pacemaker placement

Differential diagnoses

Acute respiratory distress syndrome, Anemia, Angina pectoris, Aortic regurgitation, Aortic stenosis, Asthma, Atrial fibrillation, AV nodal block, Cardiomyopathy, COPD, Drug side effects, Heart failure, Hyperkalemia, Hyperthyroidism, Hypokalemia, Hypovolemia, Interstitial lung disease, Mitral regurgitation, Mitral stenosis, Myocardial infarction, Myxoma, Paroxysmal supraventricular tachycardia, Pericarditis, Pleural effusion, Pneumonia, Pneumothorax, Pulmonary embolism, Pulmonary hypertension, Ventricular tachycardia