Cardiac Arrythmia

Cardiac Arrhythmia
Tachyarrhythmias
Cardiac rhythms whose ventricular rate exceeds 100 bpm.
1. Narrow-Complex Tachyarrhythmia (QRS <120 ms)
2. Wide-Complex Tachyarrhythmia (QRS >120 ms)
Etiology
? Disorders of Impulse Conduction (e.g., VT).
? Disorders of Impulse Formation: Enhanced automaticity (e.g., accelerated junctional and accelerated idioventricular rhythm) and triggered activity (e.g., long QT syndrome and digitalis toxicity)
? Other less common mechanisms of tachyarrhythmias.
Clinical features
? Dyspnea, angina, lightheadedness or syncope and decreased level of consciousness
? Palpitations:
? Sudden onset and termination
? Symptom abatement with breath holding or Valsalva maneuver (supraventricular tachyarrhythmia
? AV node is critical in the maintenance of this arrhythmia.
? History of organic heart disease
? Endocrinopathy
? Familial or congenital causes of arrhythmias
? Medications: (over-the-counter and herbal medications
1. Supraventricular tachyarrhythmia
2. Ventricular tachyarrhythmia
• (SVT) are often recurrent, occasionally persistent, and a frequent cause of visits to emergency departments and primary care physician offices.
Differential Diagnosis
• (AF) is the most common narrow-complex tachycardia seen : irregular with no p wave pattern
• If rate is about 150 bpm, suspect atrial flutter (AFl) with 2:1, 4:1 to 3:1, etc sawtooth.(can often accompany AF).
• Like AF, AFl is commonly associated with the postcardiac surgery period, pulmonary disease, thyrotoxicosis, and atrial enlargement.
3. Multifocal atrial tachycardia (MAT)