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An Anteroseptal Accessory Pathway in a Patient with Dextrocardia and Situs Inversus ASHLEY CHIN, M.B.Ch.B., M.Phil. and TAMARA PHIRI, M.B.Ch.B. From the Division of Cardiology, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
accessory pathway, catheter ablation, dextrocardia, Wolff-Parkinson-White syndrome A 39-year-old woman was referred to our unit with a brief history of recurrent syncopal episodes. She had no prior history of palpitations or documented arrhythmias. The patient’s standard 12-lead ECG is shown (Fig. 1, Panel A). The ECG shows an underlying atrial rhythm with preexcitation. The atrial rhythm does not appear to be sinus in origin with a P wave axis of +120°. Preexcitation is noted with a short PR interval, delta wave, and a wide QRS complex during conducted beats. Closer inspection of the morphology of the delta waves reveals unusual negative QS complexes in leads V4–V6, I, and aVL. Negative QS complexes in leads V4–V6 is a very unusual pattern of pre-excitation in a patient with a levocardia as a typical atrioventricular accessory pathway inserts into the ventricle at the base of the heart. Thus, irrespective of the location of the accessory pathway, R waves are always visible in leads V4–V6 irrespective of the degree of preexcitation or
J Cardiovasc Electrophysiol, Vol. 00, p. 1 No disclosures. Address for correspondence: Ashley Chin, M.B.Ch.B., M.Phil., Division of Pacing and Electrophysiology, University of Cape Town, Cape Town, South Africa. Fax: +27 21 4046070; E-mail: [email protected] doi: 10.1111/jce.12616
the morphology of the delta wave. Together with the abnormal P wave axis, the differential diagnosis includes abnormal ECG lead positions (unlikely, because both limb and chest leads would have to be misplaced in this case) or the heart is an abnormal position in the chest (likely). An atypical long atrioventricular accessory pathway that inserts near the left ventricular apex can cause negative QS complexes in V4–V6 but would not account for the abnormal P wave axis. Cardiac examination and chest Xray confirmed the patient had dextrocardia with situs inversus (Fig. 1, Panel B). The patient’s ECG was repeated with inversion of both the chest and limb leads (Fig. 1, Panel C). The ECG now shows a typical pattern of sinus rhythm with evidence for an anteroseptal accessory pathway with an equiphasic delta wave in V1 and a positive delta wave in aVF. An electrophysiological procedure was performed. Standard antegrade mapping of the accessory pathway localized the earliest ventricular signal to 1 o’clock along the tricuspid annulus in the RAO 40° view (anteroseptal pathway). Radiofrequency ablation with a non-irrigated catheter at 30 Watts resulted in loss of preexcitation with the second burn. Reports of WPW syndrome with dextrocardia have been reported previously with left free wall, lateral mitral atrioventricular ring, and right free wall accessory pathways. This is a unique case of an anteroseptal accessory pathway in a patient with dextrocardia. Similar to previous reports, we report a preexcitation pattern of QS waves in leads V4–V6 to be a specific sign of preexcitation and dextrocardia.
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Journal of Cardiovascular Electrophysiology
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Figure 1. Panel A: ECG with leads in the standard conventional position. Panel B: A chest X-ray showing dextrocardia with situs inversus. Panel C: ECG with inversion of the chest and limb leads. For a high quality, full color version of this figure, please see Journal of Cardiovascular Electrophysiology’s website: www.wileyonlinelibrary.com/journal/jce
EP Image
An Anteroseptal Accessory Pathway in a Patient with Dextrocardia and Situs Inversus ASHLEY CHIN, M.B.Ch.B., M.Phil. and TAMARA PHIRI, M.B.Ch.B. From the Division of Cardiology, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
accessory pathway, catheter ablation, dextrocardia, Wolff-Parkinson-White syndrome A 39-year-old woman was referred to our unit with a brief history of recurrent syncopal episodes. She had no prior history of palpitations or documented arrhythmias. The patient’s standard 12-lead ECG is shown (Fig. 1, Panel A). The ECG shows an underlying atrial rhythm with preexcitation. The atrial rhythm does not appear to be sinus in origin with a P wave axis of +120°. Preexcitation is noted with a short PR interval, delta wave, and a wide QRS complex during conducted beats. Closer inspection of the morphology of the delta waves reveals unusual negative QS complexes in leads V4–V6, I, and aVL. Negative QS complexes in leads V4–V6 is a very unusual pattern of pre-excitation in a patient with a levocardia as a typical atrioventricular accessory pathway inserts into the ventricle at the base of the heart. Thus, irrespective of the location of the accessory pathway, R waves are always visible in leads V4–V6 irrespective of the degree of preexcitation or
J Cardiovasc Electrophysiol, Vol. 00, p. 1 No disclosures. Address for correspondence: Ashley Chin, M.B.Ch.B., M.Phil., Division of Pacing and Electrophysiology, University of Cape Town, Cape Town, South Africa. Fax: +27 21 4046070; E-mail: [email protected] doi: 10.1111/jce.12616
the morphology of the delta wave. Together with the abnormal P wave axis, the differential diagnosis includes abnormal ECG lead positions (unlikely, because both limb and chest leads would have to be misplaced in this case) or the heart is an abnormal position in the chest (likely). An atypical long atrioventricular accessory pathway that inserts near the left ventricular apex can cause negative QS complexes in V4–V6 but would not account for the abnormal P wave axis. Cardiac examination and chest Xray confirmed the patient had dextrocardia with situs inversus (Fig. 1, Panel B). The patient’s ECG was repeated with inversion of both the chest and limb leads (Fig. 1, Panel C). The ECG now shows a typical pattern of sinus rhythm with evidence for an anteroseptal accessory pathway with an equiphasic delta wave in V1 and a positive delta wave in aVF. An electrophysiological procedure was performed. Standard antegrade mapping of the accessory pathway localized the earliest ventricular signal to 1 o’clock along the tricuspid annulus in the RAO 40° view (anteroseptal pathway). Radiofrequency ablation with a non-irrigated catheter at 30 Watts resulted in loss of preexcitation with the second burn. Reports of WPW syndrome with dextrocardia have been reported previously with left free wall, lateral mitral atrioventricular ring, and right free wall accessory pathways. This is a unique case of an anteroseptal accessory pathway in a patient with dextrocardia. Similar to previous reports, we report a preexcitation pattern of QS waves in leads V4–V6 to be a specific sign of preexcitation and dextrocardia.
2
Journal of Cardiovascular Electrophysiology
Vol. No.
Figure 1. Panel A: ECG with leads in the standard conventional position. Panel B: A chest X-ray showing dextrocardia with situs inversus. Panel C: ECG with inversion of the chest and limb leads. For a high quality, full color version of this figure, please see Journal of Cardiovascular Electrophysiology’s website: www.wileyonlinelibrary.com/journal/jce
