Introduction to Arrhythmias

Arrhythmias (non-normal heart rhythms) can be a challenge to the person who tries to understand them. But with a systematical approach, diagnosis is often less difficult than it seems at the beginning.

First look at the heart rate:

• >100 bpm = tachycardia
• <60 bpm = bradycardia
• are there extra beats? -> Ectopic Beats

Secondly it is important to assess the origin of the arrhythmia:

• If the QRS < 120ms (i.e. a narrow complex), then it is either a sinus arrhythmia, supraventricular rhythm or a junctional tachycardia. In tachycardias, this flowchart will lead to the right diagnosis.
• If the QRS > 120ms it is either a ventricular tachycardia or a supraventricular rhythm with additional bundle branch block. This is a challenging difficulty in arrhythmia diagnosis, therefore a flowchart has been developed for this.[1]

Normal heart rhythm is explained in:

• Sinus node rhythms and arrhythmias

Non-normal heart rhythms (arrhythmias) are described in:

• Supraventricular Rhythms
• Junctional Tachycardias
• Ventricular Arrhythmias
• AV Conduction
• Genetic Arrhythmias
• Pacemaker

• Flowchart: Approach to the Wide Complex Tachycardia
• Flowchart: Approach to the Narrow Complex Tachycardia Adapted from [2].

References

2. Blomström-Lundqvist C, Scheinman MM, Aliot EM, Alpert JS, Calkins H, Camm AJ, Campbell WB, Haines DE, Kuck KH, Lerman BB, Miller DD, Shaeffer CW, Stevenson WG, Tomaselli GF, Antman EM, Smith SC Jr, Alpert JS, Faxon DP, Fuster V, Gibbons RJ, Gregoratos G, Hiratzka LF, Hunt SA, Jacobs AK, Russell RO Jr, Priori SG, Blanc JJ, Budaj A, Burgos EF, Cowie M, Deckers JW, Garcia MA, Klein WW, Lekakis J, Lindahl B, Mazzotta G, Morais JC, Oto A, Smiseth O, Trappe HJ, and European Society of Cardiology Committee, NASPE-Heart Rhythm Society. ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias--executive summary. a report of the American college of cardiology/American heart association task force on practice guidelines and the European society of cardiology committee for practice guidelines (writing committee to develop guidelines for the management of patients with supraventricular arrhythmias) developed in collaboration with NASPE-Heart Rhythm Society. J Am Coll Cardiol. 2003 Oct 15;42(8):1493-531. DOI:10.1016/j.jacc.2003.08.013 |
3. Brugada P, Brugada J, Mont L, Smeets J, and Andries EW. A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex. Circulation. 1991 May;83(5):1649-59. DOI:10.1161/01.cir.83.5.1649 |