Atrial Tachycardia
Atrial tachycardias are not frequent if atrial fibrillation (Chapter 21) and atrial flutter (Chapter 20) are excluded. The types of atrial tachycardia differ with respect to morphology of the p wave, atrial rate, atrioventricular conduction, duration of t
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Atrial Tachycardia
AtaGlance Atrial tachycardias are not frequent if atrial fibrillation (Chapter 21) and atrial flutter (Chapter 20) are excluded. The types of atrial tachycardia differ with respect to morphology of the p wave, atrial rate, atrioventricular conduction, duration of the arrhythmia, hemodynamie consequences, electrophysiologie mechanisms, and etiology.
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ECG In all atrial tachycardias the p waves precede the QRS complex, but p morphology is different from sinusal p waves. Most atrial tachycardias are regular. Based on clinical significance, atrial tachycardias may be classified in the following way.
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'Salvos' of Atrial Premature Beats
The episodes of APBs (often 3-5 beats) are generally of moderate rate (no-150!min) and are often without symptoms. ECG 19.1 shows a longer episode of 8 beats.
2
nign' Atrial Tachycardia
This regular tachycardia is characterized by a relatively short duration (from several seconds to minutes), a moderate rate « 150/min) and occurs in otherwise healthy hearts (ECG 19.2). Therapy is only needed if there are symptoms (mostly palpitations).
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or even syncope requiring drug therapy or catheter ablation. The tachycardia occurs in healthy individuals and in patients with heart disease. ECG 19.3 demonstrates that drug conversion with adenosine mayaiso cause the treating physician's heart to tremble.
Atrial Tachycardia of Medium Duration and High Rate
The tachycardia lasts minutes to days, the rate is (individually) between 150 and 200/min (maximally 280/min) (ECG 19.3). The symptoms are malaise, palpitations, dizziness, presyncope
M. Gertsch, The ECG © Springer-Verlag Berlin Heidelberg 2004
'Inces nt' Atrial Tachycardia
The duration of this rare type of longstanding tachycardia is days to months. If the tachycardia lasts months and its rate is 150/min or more, it may induce a considerable reduction in the function of the left (and/or right) ventricle, and even chronic heart failure. The arrhythmia may have its origin in the right or left atrium and is often resistant to drugs. Restoration of sinus rhythm by catheter ablation may normalize he art function in otherwise healthy hearts, after weeks or months. However, this tachycardia also occurs in patients with heart diseases where ablation does not completely resolve the problem.
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Atrial Tachycardia with Atrioventricular Bloc
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The tachycardia usually shows 2 : 1 atrioventricular (AV) block and is often associated with heart disease (ECG 19.4). It may also be due to digitalis intoxication. In the conventional ECG, differentiation from atrial flutter type 2 (with 2 : 1 AV block) is often impossible.
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Multifocal Ectopic Atrial Tachycardia (eh otic A rial Mechanisml
This completely irregular tachycardia is very rare. The rate is 100-140/min (or less than 100/min). The morphology of the p waves changes from beat to beat, so do the PQ and the R-R in-
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tervals (ECG 19.5). The arrhythmia 'per se' has modest haemodynamic consequences. However, its usual association with
severe obstructive lung disease is
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