Interesting Cases
Title: The first reported case of successful percutaneous ablation of PVC in a patient with congenitally corrected transposition of the great arteries
A 38-year-old man who experienced severe episodes of palpitation despite treatment with sotalol 80 mg twice a day was referred to us for the evaluation of frequent PVCs. His New York Heart Association functional class was class I. Transthoracic echocardiography revealed the reversed position of the left and right ventricles, the origin of the pulmonary artery in the right-sided smooth chamber,
and the origin of the aorta in the trabeculated and hypertrophied left-sided ventricle. The contractility of both ventricles was preserved. Neither a ventricular septal defect nor an Ebstein malformation of the left-sided tricuspid valve was present, and no valvular regurgitation was noted in any of the AV valves. Mild subvalvular pulmonary stenosis with a pressure gradient of 20 mm Hg was noticed. Frequent PVCs with left bundle-branch block (LBBB) and inferior axis morphologic characteristics were evident in a surface 12-lead electrocardiogram. During 24-hour Holter monitoring, frequent bigeminy and couplet ventricular beats with the same morphologic characteristics as PVCs were found.
Because his severe symptoms could not be controlled by medical therapy, this patient was admitted to the hospital to undergo an electrophysiologic study. Placement of a diagnostic catheter inside the right sided ventricle (RV) was possible only with a deflectable catheter. No His potential was found around the right sided mitral valve. An AV Wenckebach conduction block at decremental atrial pacing of 400 msec was identified. VA conduction was absent. Premature ventricular pacing with up to 3 extrastimuli and burst pacing (up to a pacing cycle length of 350 msec) failed to induce sustained VT, even after isoproterenol infusion (8 μg/min). A contrast injection study was performed to reveal the precise location of the right and left ventricles and the interventricular septum (Figure 1).
Figure 1: Contrast ventriculograms. A :Right sided ventriculogram in AP projection,
B:Right sided ventriculogram in LAO 35 projection. C: Left sided ventriculogram in AP preojection. D: Left sided ventriculogra in LAO 35 projecion. AP: Antero posterior, LAO:Left anterior oblique.
After we evaluated the morphologic characteristics of the PVC complex (the LBBB inferior axis, which was predominantly negative in leads I and aVL), we mapped the anterior parts of the interventricular septum. Access to that region was possible only when the catheter of ablation was placed via the left subclavian vein. The frequency of PVCs decreased significantly during that stage of the procedure, and an increased dose of isoproterenol was not effective in inducing more PVCs. We then mapped the septum with a pace map. In an anteroseptal location (Figure 2), paced complexes perfectly matched with the patient's PVCs were obtained (Figure 3). No potential resembling His activity was recorded. Radiofrequency ablation (50 W, 60 degrees) in that region resulted in accelerated nonsustained VT and the resolution of PVCs thereafter. No PVC was recorded during the next 30 minutes, and the patient was transferred to the cardiology ward. No PVC was recorded during subsequent 12-hour ECG monitoring, and the patient was discharged to home the day after the procedure.
Figure 2: Catheter of ablation is placed at anteroseptal region of morphologic left ventricle (site of successful ablation) A- AP view. B- LAO 35 view. Abbreviations as in figure 1.
Figure 3: A- 12 lead electrogram revealing morphology of PVC (second complex). B- 12 lead electrogram during pacing from site of ablation matching PVCs.
This patient has been completely asymptomatic for the first 3 months after his procedure, and no PVC has been recorded on an electrocardiogram or in the repeated Holter monitoring during that time.
Discussion
Congenitally corrected transposition of the great arteries (CCTGA), which is the discordance of both atrioventricular (AV) and ventriculoatrial (VA) connections, is a rare abnormality that accounts for less than 1% of congenital heart diseases. Only 5% of patients with CCTGA have no associated lesion and survive into adulthood without surgical intervention, and arrhythmias and symptoms of heart failure due to systemic ventricular dysfunction develop in a significant number of middle-aged patients with isolated CCTGA [1]. Atrioventricular (AV) nodal conduction disease is the most prevalent heart rhythm disorder in patients with CCTGA [2]. Left-sided accessory pathways are particularly common in those patients and the successful ablation of such accessory pathways has been reported [3,4]. Atrial tachyarrhythmias tend to increase with advancing age, and they occur earlier and more frequently when CCTGA is associated with other intracardiac defects [5,6]. Cases of slow pathway ablation in patients with CCTGA affected by atrioventricular (AV) nodal reentry have also been reported [7,8]. Nevertheless, there are few reports of documented ventricular tachycardia (VT) in patients with CCTGA [9-11]. In one of those reports, scar-related VT was successfully treated with radiofrequency ablation in the failing systemic ventricle [12].
In this report, we describe radiofrequency ablation of the origin of premature ventricular contractions (PVCs) in a patient with highly symptomatic palpitation affected by CCTGA but with no significant other structural heart disorder.
In recent years, radiofrequency ablation has been used with increasing success in the treatment of arrhythmias in patients with congenital heart diseases. In the spectrum of congenital heart diseases, CCTGA is a rare abnormality; however it is frequently associated with arrhythmias. Because of the possible need for invasive procedures such as ablation or device implantation (including biventricular pacemakers) in such patients, familiarity with relevant anatomic features is critical. Fortunately, the information about morphologic characteristics of atria in patients with CCTGA is increasing [13], but because of the rarity of the procedures performed to treat ventricular arrhythmia in these patients, knowledge about the related anatomy is scant.
To our knowledge, this is the first report of the use of radiofrequency catheter ablation to successfully treat a patient with frequent PVCs associated with complete transposition of the great arteries. Because this patient had a structurally abnormal heart, those PVCs were not classified as idiopathic, but their essential characteristics (focal origin, unpredictable inducibility) resembled the focal ectopies found in patients with idiopathic PVCs. More important than the mechanism of PVCs in our patient was whether, given his complex structural cardiac malformation and the ineffectiveness of other treatment modalities, ablation was the best therapeutic choice. Malposition of marking structures such as the interventricular septum, the right atrioventricular valve, the interatrial septum, the fossa ovalis, the coronary sinus, and even the AV conduction system rendered ablation complex and potentially hazardous. For that reason, we thought that 3-dimensional mapping might be of benefit. We used a contrast injection to delineate the cardiac anatomy, but the main problem was difficulty in accessing the appropriate region. Using a 3-dimensional mapping system did not seem to be helpful. We were particularly concerned about the abnormal location of the AV conduction system with a report on a patient in whom that pathway ran around the anterior border of the pulmonary outflow tract [14]. In that report, no His potential was found in the right atrium, and complete AV block was achieved by radiofrequency ablation of the superior part of the middle third of the interventricular septum. In our patient no His potential was recorded in the site of ablation and the AV conduction properties was not affected by ablation.
Conclusion
We reported the first case of ablation of PVCs origin in a patient with CCTGA which to our best knowledge has not been reported before. Although the abnormal structural anatomy makes the procedure more complex and even riskful, Radiofrequency ablation of PVCs may be considered as a justified and effective treatment in patients with CCTGA in whom medical therapy has been ineffective.
Ali Kharazi, MD1; Mohammad Alasti, MD2
From the 1Department of Electrophysiology, Bahman General Hospital, Tehran, Iran; 2Department of Cardiology, Imam Khomeini Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran;
References
1. Graham TP Jr, Bernard YD, Mellen BG, Celermajer D, Baumgartner H, Cetta F, Connoly HM, et al. Long-term outcome in congenitally corrected transposition of the great arteries: a multi-institutional study. J Am Coll Cardiol 2000; 36:255-61.
2. Huhta JC, Maloney JD, Ritter DG, Ilstrup DM, Feldt RH. Complete atrioventricular block in patients with atrioventricular discordance. Circulation 1983; 67:1374-7.
3. Brugada J, Valls V, Freixa R, Gonzalez E, Herreros B, Matas Mariona, Mont L. Radiofrequency ablation of a posteroseptal atrioventricular accessory pathway in a left-sided tricuspid ring with Ebsteinlike anomaly in a patient with congenitally corrected transposition of the great arteries. Pacing Clin Electrophysiol 2000; 23:133-6.
4. Shah P, Dwivedi A, Downar E, Waxman M, Cameron D. Radiofrequency catheter ablation of a posteroseptal accessory pathway along the morphologic tricuspid valve in a patient with congenitally corrected transposition of the great arteries and complete atrioventricular block. J Interv Card Electrophysiol 2004; 10:171-4.
5. Presbitero P, Somerville J, Rabajoli F, Stone S, Conte MR. Corrected transposition of the great arteries without associated defects in adult patients: clinical profile and follow up. Br Heart J 1995; 74:57-9.
6. Van Hare GF, Lesh MD, Stanger P. Radiofrequency catheter ablation of supraventricular arrhythmias in patients with congenital heart disease: results and technical considerations. J Am Coll Cardiol 1993; 22:883-90.
7. Tada H, Nogami A, Naito S, Suguta M, Hoshizaki H, Oshima S, Taniguchi K. Selected slow pathway ablation in a patient with corrected transposition of the great arteries and atrioventricular nodal reentrant tachycardia. J Cardiovasc Electrophysiol 1998; 9:436-40.
8. Eisenberger M, Fox DJ, Earley MJ, Fitzpatrick AP, Davidson NC. Atrioventricular node reentrant tachycardia ablation in a patient with congenitally corrected transposition of the great vessels using the CARTO mapping system. J Interv Card Electrophysiol 2007; 19:129-32.
9. Petit J, Lancelin B, Cabanis C, Lecannelier E, Charpentier E, Charpentier A, Guize L, et all. Hisian tachycardia in an adult with corrected transposition of great vessels. Arch Mal Coeur Vaiss 1979; 72:113-7.
10. Malhotra S, Patel RN, Mandawat M. A case of congenitally corrected transposition of the great arteries with rare but life-threatening ventricular tachycardia and a coincidental single coronary ostium. J Invasive Cardiol 2007; 19:E139-41.
11. Almahmeed W, Haykowski M, Boone J, Kavanagh-Gray D, Human D, Macdonald I. Congenitally corrected transposition of the great arteries and exercise-induced ventricular tachycardia. Can J Cardiol 1996; 12:526-8.
12. Baral VR, Veldtman GR, Yue AM, Duke A, Morgan JM. Successful percutaneous ablation of ventricular tachycardia in congenitally corrected transposition of the great arteries, a case report. J Interv Card Electrophysiol 2004; 11:211-5.
13. Juneja R, Rowland E, Ho SY. Atrial morphology in hearts with congenitally corrected transposition of the great arteries: implications for the interventionist. J Cardiovasc Electrophysiol 2002; 13:158-63.
14. Andrew G, Rudnick AG, Deger FT, Greenberg RM. Ablation of atrioventricular conduction in corrected transposition of the great arteries. Heart Rhythm 2006; 3:598-600.
Because his severe symptoms could not be controlled by medical therapy, this patient was admitted to the hospital to undergo an electrophysiologic study. Placement of a diagnostic catheter inside the right sided ventricle (RV) was possible only with a deflectable catheter. No His potential was found around the right sided mitral valve. An AV Wenckebach conduction block at decremental atrial pacing of 400 msec was identified. VA conduction was absent. Premature ventricular pacing with up to 3 extrastimuli and burst pacing (up to a pacing cycle length of 350 msec) failed to induce sustained VT, even after isoproterenol infusion (8 μg/min). A contrast injection study was performed to reveal the precise location of the right and left ventricles and the interventricular septum (Figure 1).
Figure 1: Contrast ventriculograms. A :Right sided ventriculogram in AP projection,B:Right sided ventriculogram in LAO 35 projection. C: Left sided ventriculogram in AP preojection. D: Left sided ventriculogra in LAO 35 projecion. AP: Antero posterior, LAO:Left anterior oblique.
After we evaluated the morphologic characteristics of the PVC complex (the LBBB inferior axis, which was predominantly negative in leads I and aVL), we mapped the anterior parts of the interventricular septum. Access to that region was possible only when the catheter of ablation was placed via the left subclavian vein. The frequency of PVCs decreased significantly during that stage of the procedure, and an increased dose of isoproterenol was not effective in inducing more PVCs. We then mapped the septum with a pace map. In an anteroseptal location (Figure 2), paced complexes perfectly matched with the patient's PVCs were obtained (Figure 3). No potential resembling His activity was recorded. Radiofrequency ablation (50 W, 60 degrees) in that region resulted in accelerated nonsustained VT and the resolution of PVCs thereafter. No PVC was recorded during the next 30 minutes, and the patient was transferred to the cardiology ward. No PVC was recorded during subsequent 12-hour ECG monitoring, and the patient was discharged to home the day after the procedure.
Figure 2: Catheter of ablation is placed at anteroseptal region of morphologic left ventricle (site of successful ablation) A- AP view. B- LAO 35 view. Abbreviations as in figure 1.
Figure 3: A- 12 lead electrogram revealing morphology of PVC (second complex). B- 12 lead electrogram during pacing from site of ablation matching PVCs.This patient has been completely asymptomatic for the first 3 months after his procedure, and no PVC has been recorded on an electrocardiogram or in the repeated Holter monitoring during that time.
Discussion
Congenitally corrected transposition of the great arteries (CCTGA), which is the discordance of both atrioventricular (AV) and ventriculoatrial (VA) connections, is a rare abnormality that accounts for less than 1% of congenital heart diseases. Only 5% of patients with CCTGA have no associated lesion and survive into adulthood without surgical intervention, and arrhythmias and symptoms of heart failure due to systemic ventricular dysfunction develop in a significant number of middle-aged patients with isolated CCTGA [1]. Atrioventricular (AV) nodal conduction disease is the most prevalent heart rhythm disorder in patients with CCTGA [2]. Left-sided accessory pathways are particularly common in those patients and the successful ablation of such accessory pathways has been reported [3,4]. Atrial tachyarrhythmias tend to increase with advancing age, and they occur earlier and more frequently when CCTGA is associated with other intracardiac defects [5,6]. Cases of slow pathway ablation in patients with CCTGA affected by atrioventricular (AV) nodal reentry have also been reported [7,8]. Nevertheless, there are few reports of documented ventricular tachycardia (VT) in patients with CCTGA [9-11]. In one of those reports, scar-related VT was successfully treated with radiofrequency ablation in the failing systemic ventricle [12].
In this report, we describe radiofrequency ablation of the origin of premature ventricular contractions (PVCs) in a patient with highly symptomatic palpitation affected by CCTGA but with no significant other structural heart disorder.
In recent years, radiofrequency ablation has been used with increasing success in the treatment of arrhythmias in patients with congenital heart diseases. In the spectrum of congenital heart diseases, CCTGA is a rare abnormality; however it is frequently associated with arrhythmias. Because of the possible need for invasive procedures such as ablation or device implantation (including biventricular pacemakers) in such patients, familiarity with relevant anatomic features is critical. Fortunately, the information about morphologic characteristics of atria in patients with CCTGA is increasing [13], but because of the rarity of the procedures performed to treat ventricular arrhythmia in these patients, knowledge about the related anatomy is scant.
To our knowledge, this is the first report of the use of radiofrequency catheter ablation to successfully treat a patient with frequent PVCs associated with complete transposition of the great arteries. Because this patient had a structurally abnormal heart, those PVCs were not classified as idiopathic, but their essential characteristics (focal origin, unpredictable inducibility) resembled the focal ectopies found in patients with idiopathic PVCs. More important than the mechanism of PVCs in our patient was whether, given his complex structural cardiac malformation and the ineffectiveness of other treatment modalities, ablation was the best therapeutic choice. Malposition of marking structures such as the interventricular septum, the right atrioventricular valve, the interatrial septum, the fossa ovalis, the coronary sinus, and even the AV conduction system rendered ablation complex and potentially hazardous. For that reason, we thought that 3-dimensional mapping might be of benefit. We used a contrast injection to delineate the cardiac anatomy, but the main problem was difficulty in accessing the appropriate region. Using a 3-dimensional mapping system did not seem to be helpful. We were particularly concerned about the abnormal location of the AV conduction system with a report on a patient in whom that pathway ran around the anterior border of the pulmonary outflow tract [14]. In that report, no His potential was found in the right atrium, and complete AV block was achieved by radiofrequency ablation of the superior part of the middle third of the interventricular septum. In our patient no His potential was recorded in the site of ablation and the AV conduction properties was not affected by ablation.
Conclusion
We reported the first case of ablation of PVCs origin in a patient with CCTGA which to our best knowledge has not been reported before. Although the abnormal structural anatomy makes the procedure more complex and even riskful, Radiofrequency ablation of PVCs may be considered as a justified and effective treatment in patients with CCTGA in whom medical therapy has been ineffective.
Ali Kharazi, MD1; Mohammad Alasti, MD2
From the 1Department of Electrophysiology, Bahman General Hospital, Tehran, Iran; 2Department of Cardiology, Imam Khomeini Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran;
References
1. Graham TP Jr, Bernard YD, Mellen BG, Celermajer D, Baumgartner H, Cetta F, Connoly HM, et al. Long-term outcome in congenitally corrected transposition of the great arteries: a multi-institutional study. J Am Coll Cardiol 2000; 36:255-61.
2. Huhta JC, Maloney JD, Ritter DG, Ilstrup DM, Feldt RH. Complete atrioventricular block in patients with atrioventricular discordance. Circulation 1983; 67:1374-7.
3. Brugada J, Valls V, Freixa R, Gonzalez E, Herreros B, Matas Mariona, Mont L. Radiofrequency ablation of a posteroseptal atrioventricular accessory pathway in a left-sided tricuspid ring with Ebsteinlike anomaly in a patient with congenitally corrected transposition of the great arteries. Pacing Clin Electrophysiol 2000; 23:133-6.
4. Shah P, Dwivedi A, Downar E, Waxman M, Cameron D. Radiofrequency catheter ablation of a posteroseptal accessory pathway along the morphologic tricuspid valve in a patient with congenitally corrected transposition of the great arteries and complete atrioventricular block. J Interv Card Electrophysiol 2004; 10:171-4.
5. Presbitero P, Somerville J, Rabajoli F, Stone S, Conte MR. Corrected transposition of the great arteries without associated defects in adult patients: clinical profile and follow up. Br Heart J 1995; 74:57-9.
6. Van Hare GF, Lesh MD, Stanger P. Radiofrequency catheter ablation of supraventricular arrhythmias in patients with congenital heart disease: results and technical considerations. J Am Coll Cardiol 1993; 22:883-90.
7. Tada H, Nogami A, Naito S, Suguta M, Hoshizaki H, Oshima S, Taniguchi K. Selected slow pathway ablation in a patient with corrected transposition of the great arteries and atrioventricular nodal reentrant tachycardia. J Cardiovasc Electrophysiol 1998; 9:436-40.
8. Eisenberger M, Fox DJ, Earley MJ, Fitzpatrick AP, Davidson NC. Atrioventricular node reentrant tachycardia ablation in a patient with congenitally corrected transposition of the great vessels using the CARTO mapping system. J Interv Card Electrophysiol 2007; 19:129-32.
9. Petit J, Lancelin B, Cabanis C, Lecannelier E, Charpentier E, Charpentier A, Guize L, et all. Hisian tachycardia in an adult with corrected transposition of great vessels. Arch Mal Coeur Vaiss 1979; 72:113-7.
10. Malhotra S, Patel RN, Mandawat M. A case of congenitally corrected transposition of the great arteries with rare but life-threatening ventricular tachycardia and a coincidental single coronary ostium. J Invasive Cardiol 2007; 19:E139-41.
11. Almahmeed W, Haykowski M, Boone J, Kavanagh-Gray D, Human D, Macdonald I. Congenitally corrected transposition of the great arteries and exercise-induced ventricular tachycardia. Can J Cardiol 1996; 12:526-8.
12. Baral VR, Veldtman GR, Yue AM, Duke A, Morgan JM. Successful percutaneous ablation of ventricular tachycardia in congenitally corrected transposition of the great arteries, a case report. J Interv Card Electrophysiol 2004; 11:211-5.
13. Juneja R, Rowland E, Ho SY. Atrial morphology in hearts with congenitally corrected transposition of the great arteries: implications for the interventionist. J Cardiovasc Electrophysiol 2002; 13:158-63.
14. Andrew G, Rudnick AG, Deger FT, Greenberg RM. Ablation of atrioventricular conduction in corrected transposition of the great arteries. Heart Rhythm 2006; 3:598-600.
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