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Bradyarrhythmias occur when the heart rate is <60 beats per minute (bpm); can be physiologic, such as in young individuals and in well-trained athletes, or pathologic and symptomatic. Typically, symptoms occur when the heart rate is <40 beats per minute.
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In the setting of a reversible cause, the only treatment indicated is to avoid the inciting cause.
Indications for permanent pacing include evidence of infranodal disease or symptomatic bradycardia at any level (SA node, AV node, or infranodal) that is spontaneous or secondary to the need for advancement of medical therapy (β-blocker, calcium channel blocker, etc); symptoms include dizziness, fatigue, syncope, poor exercise tolerance, and so on.
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Tachyarrhythmias occur when the heart rate is >100 beats per minute and are divided into narrow QRS complex and wide QRS complex tachyarrhythmias.
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This can be further divided into supraventricular tachyarrhythmias (SVT), atrial fibrillation (AF), and atrial flutter.
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Supraventricular Tachyarrhythmias
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