Palpitations after a MAZE Procedure: Difference between revisions

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m (New page: {{NHJ| |mainauthor= '''A.A.M. Wilde, H.H.D. Idzerda''' |edition= 2005:02,72 }} Figure 1|thumb A 75-year-old lady presented with palpitations. Her med...)
 
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[[Puzzle_20075_2_072_Answer|Answer]]
[[Puzzle_20075_2_072_Answer|Answer]]
The initial four beats on the electrocardiogram are
compatible with sinus rhythm at a slightly irregular
rate. After the 4th beat an extrasystole initiates a narrow
QRS complex tachycardia with a cycle length of 340
ms (rate of ±180 beats/min). The initiating P wave
has a different morphology than the sinus P wave. Its
morphology is (also) positive in the inferior leads and
negative in lead aVL, indicating a left atrial superior
origin. The same P wave is presumably superimposed
on the T wave of the subsequent beats (in lead aVL the
negative P wave seems clearly discernable).
Based on the morphology of the P wave the most
likely diagnosis is a left atrial tachycardia, which is not
an uncommon finding after a MAZE procedure. An
alternative diagnosis could be AV nodal reentrant
tachycardia but this is usually initiated by an atrial
extrasystole with a long PR interval (the ‘slow pathway’)
followed by a retrograde P wave (conducted through
the ‘fast pathway’). The morphology and timing of
the P wave are not compatible with common type AV
nodal reentrant tachycardia or uncommon type AV
nodal reentrant tachycardia (the morphology in
particular). An orthodromic AV reentry tachycardia
(with a concealed bypass) is not likely either because
of the presumable positive P wave in the inferior leads.
In summary, the most likely diagnosis is a left atrial
tachycardia post MAZE procedure.

Revision as of 20:20, 8 October 2007

Author(s) A.A.M. Wilde, H.H.D. Idzerda
NHJ edition: 2005:02,72
These Rhythm Puzzles have been published in the Netherlands Heart Journal and are reproduced here under the prevailing creative commons license with permission from the publisher, Bohn Stafleu Van Loghum.
The ECG can be enlarged twice by clicking on the image and it's first enlargement
Figure 1

A 75-year-old lady presented with palpitations. Her medical history reveals cardiac surgery with a mitral valve repair combined with a MAZE procedure two years prior to presentation. In the past two years she had been without complaints. The current palpitations are associated with dizziness, and a general uncomfortable feeling. Upon physical examination blood pressure is normal and the pulse is regular at 190 beats/min. Because of the high rate, the heart sounds could not be interpreted. The ECG at presentation is shown in figure 1. Vagal manoeuvres were not effective nor was adenosine up to a dose of 18 mg.

What is your diagnosis?

Answer