ECG RHYTHM LAB

Sources & limitations

The rhythm descriptions and timing rules were cross-checked against these references. Software tests and reference checks do not constitute clinical validation; independent educator review remains pending.

• American Heart Association · Arrhythmias
• AHA · Premature contractions
• Merck Manual · AV block
• Merck Manual · Ectopic supraventricular rhythms

Additional pattern context:

• NCBI Bookshelf · Second-degree AV block
• NCBI Bookshelf · Torsades de Pointes

These are simplified single-lead teaching signals. A 2:1 strip alone cannot reliably distinguish Mobitz I from Mobitz II. A twisting waveform alone cannot establish torsades without QT and clinical context. No treatment recommendations, ACLS certification or AHA endorsement are offered.