RHYTHM PUZZLE
A
narrow
sensitive
QRS to
complex tachycardia
Isoptin
A.A.M. Wilde, RH. Bakker
Figure 1.
Figure 2.
A.A.M. Wild Department of Cardiology, Amsterdam Medical Centre, Amsterdam, the Netherlands R.H. Bakker Departrnent of Cardiology, Slotervaart Hospital, Amsterdam, the Netherlands
Correspondence to: A.A.M. Wilde Department of Cardiology, Academic Medical Centre, PO Box 226600, 1100 DD Amsterdam, the Netherlands E-mail: [email protected]
268
A54-year-old man presented with palpitations. He
had no other symptoms. Physical examination revealed, with the exception of a fast regular heart rhythm (200 beats/min), no abnormalities. His ECG is shown in figure 1. Intravenous verapamil terminated the tachycardia and a second ECG (figure 2) was taken. What is your diagnosis? c Answer You will find the answer on page 279. Nethands Heart Journal, Volume 14, Number 7/8, August 2006
(W
RHYTHM PUZZLE
Answer to the rhythm puzzle on page 268 Figure 1 shows a narrow-complex tachycardia (rate
180 beats/min). The QRS complex is 84 msec wide, and has an intermediate axis. A P wave is not easy to discern, but could be present in the mid part of the T wave (most clearly seen in leads II and aVF). The Pwave axis cannot be determined. The differential diagnosis of this tachycardia is orthodromic circus movement tachycardia, AV-nodal re-entry tachycardia or atrial tachycardia. The position of the P wave at some distance from the QRS complex is in favour of an orthodromic tachycardia (or an atrial tachycardia with first-degree atrioventricular (AV) block). Isoptin terminates the tachycardia and that is usually indicative of involvement of the AV node. Hence, an orthodromic tachycardia is the most likely diagnosis. The ECG after termination ofthe tachycardia (figure 2) showed sinus rhythm with a normal PQ interval
#C
Netherlands Heart Journal, Volume 14, Number 7/8, August 2006
(140 msec), followed by a normal QRS complex in the first six beats. In the rhythm strip at the bottom of the panel, the next three QRS complexes are preceded by the same configuration P wave but with a shorter PQ interval (90 msec). These QRS complexes start with a Q wave. In the three precordial leads above the rhythm strip a discrete A-wave is visible (electroneutral in V1 and positive in leads V2 and V3). In the left precordial leads (last complex) the A-wave changes from positive (V4) to neutral-negative (V6). Hence, this ECG shows evidence of intermittent pre-excitation with a Kent bundle in the inferior wall, presumably just left ofthe septum. For the exact location ofthe Kent bundle pre-excitation should be present in the extremity leads. In conclusion, in the presence of (intermittent) preexcitation the tachycardia is most likely an orthodromic re-entrant tachycardia. c
279
A
narrow
sensitive
QRS to
complex tachycardia
Isoptin
A.A.M. Wilde, RH. Bakker
Figure 1.
Figure 2.
A.A.M. Wild Department of Cardiology, Amsterdam Medical Centre, Amsterdam, the Netherlands R.H. Bakker Departrnent of Cardiology, Slotervaart Hospital, Amsterdam, the Netherlands
Correspondence to: A.A.M. Wilde Department of Cardiology, Academic Medical Centre, PO Box 226600, 1100 DD Amsterdam, the Netherlands E-mail: [email protected]
268
A54-year-old man presented with palpitations. He
had no other symptoms. Physical examination revealed, with the exception of a fast regular heart rhythm (200 beats/min), no abnormalities. His ECG is shown in figure 1. Intravenous verapamil terminated the tachycardia and a second ECG (figure 2) was taken. What is your diagnosis? c Answer You will find the answer on page 279. Nethands Heart Journal, Volume 14, Number 7/8, August 2006
(W
RHYTHM PUZZLE
Answer to the rhythm puzzle on page 268 Figure 1 shows a narrow-complex tachycardia (rate
180 beats/min). The QRS complex is 84 msec wide, and has an intermediate axis. A P wave is not easy to discern, but could be present in the mid part of the T wave (most clearly seen in leads II and aVF). The Pwave axis cannot be determined. The differential diagnosis of this tachycardia is orthodromic circus movement tachycardia, AV-nodal re-entry tachycardia or atrial tachycardia. The position of the P wave at some distance from the QRS complex is in favour of an orthodromic tachycardia (or an atrial tachycardia with first-degree atrioventricular (AV) block). Isoptin terminates the tachycardia and that is usually indicative of involvement of the AV node. Hence, an orthodromic tachycardia is the most likely diagnosis. The ECG after termination ofthe tachycardia (figure 2) showed sinus rhythm with a normal PQ interval
#C
Netherlands Heart Journal, Volume 14, Number 7/8, August 2006
(140 msec), followed by a normal QRS complex in the first six beats. In the rhythm strip at the bottom of the panel, the next three QRS complexes are preceded by the same configuration P wave but with a shorter PQ interval (90 msec). These QRS complexes start with a Q wave. In the three precordial leads above the rhythm strip a discrete A-wave is visible (electroneutral in V1 and positive in leads V2 and V3). In the left precordial leads (last complex) the A-wave changes from positive (V4) to neutral-negative (V6). Hence, this ECG shows evidence of intermittent pre-excitation with a Kent bundle in the inferior wall, presumably just left ofthe septum. For the exact location ofthe Kent bundle pre-excitation should be present in the extremity leads. In conclusion, in the presence of (intermittent) preexcitation the tachycardia is most likely an orthodromic re-entrant tachycardia. c
279
