Refractory Supraventricular Reentry Tachycardia Treated by Radiofrequency Atriai Pacemaker

CASE REPORT

Refractory Supraventricular Reentry Tachycardia Treated by Radiofrequency Atriai Pacemaker FRANCIS SOLTI, ZOLTAN SZABO, ELMER CZAKO, ALEX BODOR, and FRANCIS RENYIVAMOS JR. From the Itistitute of Cardiovascular Surgery of the Setnmelweis Medical University School, Budapest, Hungary SOLTI, F., ET AL,: Refractory supraventricular reentry tachycardia treated by radio/requency atriaJ pacemaker. The authors report on a case of drug-resistant supraventricuiar tachycardia with frequent and iong-iasting paroxysmal attacks. ElectrophysioJogic study revealed that the supraventricuiar tachycardia was based on a reentry circuit. The attack was reguJarJy induced by premature deiay 340400 ms atriai stimulation and il could aiways be terminated by rapid atriai stimuiation within 1-2 seconds. Atrioventricuiar 2:1 hlock occurred with very rapid atriai stimulation of > 190/min. The patient received a radiofrequency atriai pacemaker, and at the first sign of a tachyarrliythmia he switched on the instrument for 1-2 sec. and the attack was promptly terminated, (PACE, Vol. 5, March-Aprii, 1982] tachyarriiytiimia, reentry mechanism, arrhytiimia anaiysis, accessory pathway, pacemaker therapy

Pacemaker therapy has opened new vistas for the treatment of tachyarrhythmias; but not all types of paroxysmal tachycardia are amenable to pacemaker therapy. Arrhythmia analysis helps to elucidate the origin and the pathophysiological basis of the arrhythmia and aids in selecting the mode of treatment for the tachycardias. This paper reports a case of paroxysmal tachycardia and the application of an atriai radiofrequency pacemaker to treat supraventricular paroxysmal tachycardia. Case Report A 41-year-ald man had a history of tachycardia attacks for five years. During the previous two years he had more frequent episodes (3-4 times a day) and each lasted for a longer period (2-4 hrs). Tbe patient had no symptoms of cardiomyopatby, valvular heart disease, or coronary disease. Tbe episodes of paroxysmal tachyAddress for reprints: Dr, F. Soiti, D. Med. Sci., Institute of Cardiovascular Surgery, Budapest, Varosmajor Str. 68., H1122, Budapest, Hungary. Received December 3, 1979; revisions received April 8,1980 and March 17, 1961; accepted May 1, 1981.

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cardia could not be prevented by any of the following antiarrhythmic agents: propranolol 20 mg qid, lidocaine 250 mg qid, procainamide 250 mg qid, diphenylhydantoin 100 mg qid, amiodarone 200 mg tid, verapamil 40 mg tid, and quinidine 0.20 g tid for 4-10 weeks. Arrhythmia analysis was indicated to determine the electrophysiological basis of the arrhythmia and to evaluate the possibility of pacemaker implantation. A standard electropbysiological study was carried out and special attention was given to the initiation and termination of the tachycardia by electrical stimulation of the heart. For the electrical stimulation of the right atrium and the right ventricle, a unipolar electrode was introduced via the left femoral vein. For recording of the His bundle eiectrogram and the intracavitary eiectrogram, a septapolar catheter was introduced into the right femoral vein and a Medtronic* 5831 pulse generator and a 5825 programmable stimulator were used for programmed electrical stimulation of the heart. To provoke the tachycardia premature delay 100-500 ms stimulation was applied in different *Medtronic, Inc, Minneapolis, Minnesota, U.S.A.

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Figure 1. ECG recorded at 25 mm/sec paper-speed; I, U, HI, and AVR limb leads. The tracing was recorded during o tachycardia attack. At the beginning of the episode the patient switched the pacemaker on f ^), and the tachycardia terminated during rapid atrial stimuiation, and sinus rhythm resumed. areas of the right atrium and ventricle. The electrophysiological evaluation was performed by atriai or ventricular stimulation during sinus rhythm; only tbe determination of the SNRT was performed by electrical drive of the atrium. Electrophysiological Study The pacemaker function of the sinus node proved normal. Sinus node recovery time and sinoatrial conduction time were also in the normal range. The atriai and atrioventricular conduction times were normal: P-A = 20 ms, A-H = 70 ms, H-V = 60 ms; an accessory conduction pathway was revealed. The conduction time of the accessory pathway was a Uttle shorter (A-H = 50 ms, H-V = 60 msec). The refractory period of the normal atrioventricular conduction pathway was 400 ms; earlier atriai stimulus delay < 400 ms were conducted on the accessory pathway. By rapid atriai stimulation > 190/min, 2:1 conduction block appeared in the accessory pathway. The effective refractory period of the atrium was very short [AERP = 180 ms). while that of the ventricle was in the normal range (VERP = 260 ms). The tachycardia could be regularly initiated by a single premature atriai stimulus (de-

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lay 340-400 ms). The provoked tachyarrhythmia was based on a reentry circuit, anterograde conduction on the accessory pathway, and retrograde conduction on the normal conduction pathway. By rapid atriai stimulation of > 160/min the episodes could be repeatedly terminated within a short time ( 11 montbs). He has successfully used rapid atriai pacing once or twice a day for interruption of tbe tacbycardia. Discussion Tbe majority of tachyarrhythmias are of supraventricular origin and a substantial number of them can be effectively treated by rapid

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RADIOFREQUENCY ATRIAL PACEMAKER

atrial pacing.^-" For the interruption of supraventricular tachycardia attacks, radiofrequency atrial pacemakers have proved suitable.'-*"'" The treatment of supraventricular tachycardia with rapid atrial pacing has two requirements: 1) that the tachycardia attack could repeatedly he initiated and terminated during electrophysiological study hy rapid atrial stimulation; 2) that the

atrioventricular conduction should not he very fast; rapid atrial stimulation of > 200 min should not be conducted in 1:1 ratio to the ventricle. In selected cases the inductive radiofrequency rapid atrial stimulation has proven very effective for interruption of supraventricular tachycardias.

References 1. Arbel, E.R., Cohen. H.C., Langerdorf, R., et al.: Successful treatment of drug-resistant atrial tachycardia and intractable congestive heart failure with permanent coupled atrial pacing. Am. /. CordJo]., 41:336. 1978. 2. Cooper, T.B., McLean. W.A.H., and Waldo. A.L,: Overdrive pacing for supraventricular tachycardia. A review of theoretical implications and therapeutic techniques. PACE, 1:196. 1978. 3. Davidson. R,M,, Wallace. A,G.. Sealy, W,C,. et al.: Electrically induced atrial tachycardia with block: a therapeutic application of permanent radiofrequency atrial pacing. Circu/ation, 44:1014. 1971. 4. Fischer, J.D.. Cohen, H.L., Mehra, R., et al.: Cardiac pacing and pacemakers IL Serial electrophysiologic-pharmacologic testing for control of recurrent tachyarrhythmias. Am. Heart /,, 93:658, 1977.

5. Frueham, CTh., Meyer, I.A., Klie, J.H., et al.: Refractory paroxysmal supraventricular tachycardia. Treatment with patient controlled permanent frequency atrial pacemaker. Am. Heart /., 87:229, 1974. 6. Iwa. T., Abe, H.. Sugiki, K., et a!.: Treatment of supraventricular tachycardia with inductive radiofrequency atrial stimulation. Progr. Med., 74:372, 1970, 7. Naime. A., Bello. A., Jaen. R., et al.: The use of a permanent pacemaker for ventricular tachyarrhythmia without atrioventricular block. /. Cardiovasc. Surg., 13:204, 1972. 8. Preston. T.A.. and Kirsh, M.M.: Permanent pacing of the left atrium for treatment of WPW tachycardia. Circulation, 42:1073. 1970.

I connected her to the string galvanometer for two hours and recorded the electrocardiogram; during this time she had one attack after another. Thus I obtained records of a large number of brief attacks, from which it was evident that during each attack ventricular flutter, or a transition from ventricular flutter to fibrillation, was present. The tracings also showed that there was no relationship between the P waves and the ventricular complexes, so that complete heart block was present. De Boer, S.: On the origin and essence ot the Morgagni-Adams-Stokes Ann. Intern. Med. 37:48-64. 1952.

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syndrome.

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