Tachyarrhythmias

Paroxysmal Tachycardias 150-250 bpm

• Paroxysmal Atrial Tachycardia
• An irritable atrial focus produces a normal wave sequence, if P' waves are visible.
• P.A.T. with block
• Same as P.A.T. but only every second (or more) P' wave produces a QRS.
• Paroxysmal Junctional Tachycardia
• AV Junctional focus produces a rapid sequence of QRS-T cycles.
• QRS may be slightly widened.
• Paroxysmal Ventricular Tachycardia
• Ventricular focus produces a rapid sequence of (PVC-like)
• Wide ventricular complexes.

Flutter (250-350 bpm)

• Atrial Flutter
• Continuous (“saw tooth”) rapid sequence of atrial complexes from a single rapid-firing atrial focus. Many flutter waves needed to produce a ventricular response.
• Ventricular Flutter / Torsades
• A rapid series of smooth sine waves from a single rapid-firing ventricular focus; usually in a short burst leading to Ventricular Fibrillation.
• Torsades de Pointes if amplitude of wave varies like a ribbon.

Fibrillation (350-450 bpm)

• Erratic (multifocal) rapid discharges
• Atrial Fibrillation
• Multiple atrial foci rapidly discharging produce a jagged baseline of tiny spikes.
• Ventricular (QRS) response is irregular.
• Ventricular Fibrillation
• Multiple ventricular foci rapidly discharging produce a totally erratic ventricular rhythm
• without identifiable waves.
• Needs immediate treatment.