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Triple ventricular fusion due to intermittent ventricular parasystole in the Wolff-Parkinson-White syndrome
290 Brief communications
August 1981 American Hurt Journal
Reversible obstruction of the ventricular outflow tract. Am J Cardiol 11:1, 1963. 6. Raah W: The pathogenic significance of adrenalin and related substances in the heart muscle. Exp Med Surg 1:188, 1943. 7. Cueto L, Arriaga J, Zinser J: Echocardiographic changes in pheochromocytoma. Chest 7§:600, 1979. 8. Engelman K, Sjoerdsma A: Chronic medical therapy for pheochromocytoma: A report of four cases. Ann Intern Med 61:229, 1964.
9. Wiswell JG, Crago RM: Reversible cardiomyopathy with pheochromocytoma. Trans Am Clin Climatol Assoc 80:185, 1968. 10. ComePC, Bulkley BH, Goodman ZD, Hutchins GM, Pitt B, Fortuin NJ: Hypercontractile cardiac states simulating hypertrophic cardiomyopathy. Circulation 55:901, 1977.
Triple ventricular fusion due to intermittent ventricular parasystole in the Wolfl.Parkinson-White syndrome Shinji Kinoshita, M.D., Masayuki Sakurai, M.D., and Taro Yasukouchi, M.D. Sapporo, Japan
Recently, Kinoshita "3 showed the presence of seconddegree entrance block of Mobitz type I in patients with intermittent ventricular parasystole. The present communication is the first report of triple ventricular fusion due to the coexistence of such intermittent ventricular parasystole with the Wolff-Parkinson-White (WPW) syndrome. ECGs were recorded from a 21-year-old asymptomatic man without otherwise apparent heart disease. Figs. 1 to 3 present parts of a long continuous recording. In Fig. 1 the configuration of sinus beats shows type A WPW pattern, and the configuration of ectopic beats resembles left bundle branch block pattern. This indicates that the preexcitation area of the sinus impulse is situated in the left ventricle (LV), while the ectopic focus is in the right ventricle (RV). The ectopic beats show intermittent ventricular parasystole due to second-degree entrance block of Mobitz type I. 1-3 Diagrams below the strips of Fig. 2 illustrate such second-degree entrance block. In the diagrams, shaded bars represent the long absolute refractory period in the pathway containing the parasystolic focus. The diagrams show that when a sinus impulse conducted to the RV (e.g., DS3 in the top strip) falls in the absolute refractory period of the pathway, the parasystolic focus is protected from this sinus impulse: On the other hand, From the Second Department of Medicine and the Department of Cardiovascular Medicine, Hokkaido University School of Medicine; and the Department of Medicine, Higashi Nippon Gakuen University School of Dentistry. Supported in part by a grant-in-aid for scientific research from the Ministry of Education, Science and Culture of the Japanese Government. Received for publication Oct. 17, 1980; revision received March 6, 1981; accepted March 30, 1981. Reprint requests: Shinji Kinoshita, M.D., the Second Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
0002-8703/81/080290 + 03500.30/0© 1981 The C. V. Mosby Co.
Fig. 1. Sinus beats showing type A Wolff-ParkinsonWhite (WPW) pattern and parasystolic beats resembling left bundle branch b l o c k pattern. Time intervals are expressed in hundredths of a second. DS = sinus beat; E = ectopic (parasystolic) beat.
when a conducted sinus impulse (e.g., DSll in the top strip) falls after the absolute refractory period of the pathway, it reaches and discharges the parasystolic focus after some delay, and then becomes a concealed reentrant ventricular extrasystole. After that, concealed reentrant bigeminal rhythm 3.4 continues until a parasystolic beat reappears. In Figs. 2 and 3, triple ventricular fusion beats are seen. In these fusion beats, the ventricles are simultaneously stimulated by three impulses of different origins: (1) an impulse coming through the accessory pathway and producing the delta wave (D), (2) a sinus impulse coming through the normal AV junction (S), and (3) an impulse coming from the ectopic (parasystolic) focus (E). The triple ventricular fusion beats have various configurations. These fusion beats can be classified into several groups. In the fusion beat EDS (the bottom strip of Fig, 3), impulse E invades the ventricles earlier than impulse D. In the fusion beat D/E S (Fig. 3), the impulses D and E invade the ventricles simultaneously, in which case the fusion beat shows a narrow QRS complex because the parasystolic focus and the preexcitation area of impulse D are situated in different ventricles. In the fusion beat DES (the bottom strip of Fig. 2), impulse E invades the ventricles later than impulse D, but earlier than impulse S. In the fusion beat DSE (the middle strip of Fig. 2), impulse E invades the ventricles later than impulse S. Prior to the present report, triple ventricular fusion in the WPW syndrome was noted in only a few patients with ventricular escape beats ~' or continuous ventricular parasystole." However, this is the initial report of triple ventricular fusion due to coexistence of the WPW syndrome with intermittent ventricular parasystole.
Volume
102
Number 2
Brief communications
Fig. 2. The WPW syndrome with intermittent ventricular parasystole due to second-degree entrance block of Mobitz type I, occasionally showing triple ventricular fusion. The top and middle strips are continuous. In the bottom strip sinus rhythm is slowed because of vagal stimulation. The numbers in the strips indicate intervals between a parasystolic beat and the following sinus beat. S h a d e d bars in the diagrams below the strips represent the absolute refractory period in the reentrant pathway containing the parasystolic focus. Vertical dashed lines in the diagrams represent intraventricular conduction of the sinus or parasystolic impulse leading to the reentrant pathway. ED, DES, and D S E = ventricular fusion beats; L V = left ventricle; R V = right ventricle; R P = reentrant pathway containing the parasystolic focus.
Fig. 3. Triple ventricular fusion beats showing various configurations. The first two strips are continuous. T h e numbers in the strips indicate intervals between a parasystolic beat and the following sinus beat. ED, EDS, D / E S, D E S , and D S E = ventricular fusion beats.
291
292
August 1981 American Heart Journal
Brief communications !
REFERENCES
1. Kinoshita S: Wenckebach phenomenon of entrance block in intermittent ventricular parasystole. Chest $6:530, 1974. 2. Kinoshita S: Intermittent parasystole originating in the reentrant path of ventricular extrasystoles. Chest 72:201, 1977. 3. Kinoshita S: Mechanisms of ventricular parasystole. Circulation 58:715, 1978. 4. Kinoshita S: Concealed ventricular extrasystoles due to interference and due to exit block. Circulation 52:230, 1975. 5. Myburgh DP, Carton J, Schamroth JM: Triple ventricular fusion in Wolff-Parkinson-White pattern. Chest 77:421, 1980. 6. Dubb A, Schamroth L: Ventricular parasystole with the Wolff-Parkinson-White syndrome. Chest 75:607, 1979.
Clinical comparison of indirectly and directly determined sinoatrial conducUon time Peter Rakovec, M.D., Ph.D., Japec Jakopin, M.D., Primo~ Rode, M.D., Miran F. Kenda, M.D., Ph.D., and M a t i j a Horvat, M.D., Ph.D. Ljubljana, Yugoslavia
Two methods of indirect estimation of sinoatrial node (SAN) conduction time (SACT) are c u r r e n t l y employed: (1) programmed p r e m a t u r e a t r i a l stimulation technique 1 and (2) modality utilizing a brief period of constant a t r i a l pacing. 2 While the l a t t e r m e t h o d is more simply and rapidly applied, it is subject to the same sources of error as those of the p r e m a t u r e a t r i a l stimulation technique. 3 Recently, a means of directly recording S A N electrical activity by endocardial catheterization has been described. 4 T h e purpose of this communication was to compare the new method of direct S A C T m e a s u r e m e n t 4 to an indirect method. ~ Such comparison is i m p o r t a n t because of the direct approach limitations,' which include low success rate and technical difficulty. Fifteen patients were studied who underwent temporary pacemaker electrode insertion because of dizziness and syncope. Their m e a n age was 59 years; six were men and nine were women. T h e patients had sick sinus syndrome (SSS) or AV block of different degree. After obtaining informed consent and without c o n c o m i t a n t cardioactive drugs, an electrode c a t h e t e r was passed via the right femoral vein or the left basilic vein a n d positioned at the superior vena cava-to-right a t r i a l junction. Bipolar S A N electrograms were recorded at paper speed 50 m m / s e c and high amplification 200 ~V/cm. Direct From the Cardiological Clinic and Center for Intensive Internal Medicine, Clinical Center, and Institute of Physiology, Medical Faculty. Received for publication Dec. 19, 1980; revision received March 23, 1981; accepted Apr. 3, 1981. Reprint requests: Dr. Peter Rakovec, Cardiological Clinic, Clinical Center, Zalo~ka 7, 61105 Ljubljana, Yugoslavia.
0002-8703/81/080292 + 03500.30/0 © 1981 The C. V. Mosby Co.
~CT Fig. 1. Record of S A N electrogram (SANE). Shown are the diastolic slope (A), the upstroke slope (B), and the primary negativity (C). Sinoatrial conduction time (SA CT) is measured from the point of departure of the upstroke slope from the t r a j e c t o r y of the diastolic slope to the beginning of the P wave in ECG lead II (voltage increased).
measurement of S A C T is shown in Fig. 1; indirectly S A C T was estimated by the constant atrial pacing technique. 2 Representative examples of both methods in a p a t i e n t with normal (Fig. 2) and in another p a t i e n t with prolonged (Fig. 3) S A C T are demonstrated. Mean value of directly measured SACT was 105 + 10 msec (SEM) and of indirectly estimated S A C T 117 _+ 12 msec; these mean values were not significantly different. The linear correlation coefficient between measured and estimated S A C T was 0.88 (p < 0.001) {Fig. 4). Estimation of S A C T by the indirect method exhibited a mean error of 16.5% when compared to the direct measurement. S A C T (measured by both methods) was prolonged ( > 120 msec) in all the five patients with SSS and in two patients with AV block. Experimental and clinical studies by Cramer et a12 and by H a l i m a n et al. 4' 6 have established the validity of directly obtained S A N recordings. Similar results were reported by Castillo Fenoy et al., 7 as well as by Rugienius and Steponeniene2 However, G r a n t et a12 compared estimates of S A C T obtained by constant atrial pacing to directly measured SACT in isolated rabbit right a t r i a l preparations; correlation between both values was satisfactory (r = 0.7) with 30% mean error of estimated SACT. While a greater discrepancy between indirectly and directly determined S A C T might have been anticipated, the study of G r a n t et al. 3 and our investigation reported herein document t h a t the indirect values of S A C T do n o t
August 1981 American Hurt Journal
Reversible obstruction of the ventricular outflow tract. Am J Cardiol 11:1, 1963. 6. Raah W: The pathogenic significance of adrenalin and related substances in the heart muscle. Exp Med Surg 1:188, 1943. 7. Cueto L, Arriaga J, Zinser J: Echocardiographic changes in pheochromocytoma. Chest 7§:600, 1979. 8. Engelman K, Sjoerdsma A: Chronic medical therapy for pheochromocytoma: A report of four cases. Ann Intern Med 61:229, 1964.
9. Wiswell JG, Crago RM: Reversible cardiomyopathy with pheochromocytoma. Trans Am Clin Climatol Assoc 80:185, 1968. 10. ComePC, Bulkley BH, Goodman ZD, Hutchins GM, Pitt B, Fortuin NJ: Hypercontractile cardiac states simulating hypertrophic cardiomyopathy. Circulation 55:901, 1977.
Triple ventricular fusion due to intermittent ventricular parasystole in the Wolfl.Parkinson-White syndrome Shinji Kinoshita, M.D., Masayuki Sakurai, M.D., and Taro Yasukouchi, M.D. Sapporo, Japan
Recently, Kinoshita "3 showed the presence of seconddegree entrance block of Mobitz type I in patients with intermittent ventricular parasystole. The present communication is the first report of triple ventricular fusion due to the coexistence of such intermittent ventricular parasystole with the Wolff-Parkinson-White (WPW) syndrome. ECGs were recorded from a 21-year-old asymptomatic man without otherwise apparent heart disease. Figs. 1 to 3 present parts of a long continuous recording. In Fig. 1 the configuration of sinus beats shows type A WPW pattern, and the configuration of ectopic beats resembles left bundle branch block pattern. This indicates that the preexcitation area of the sinus impulse is situated in the left ventricle (LV), while the ectopic focus is in the right ventricle (RV). The ectopic beats show intermittent ventricular parasystole due to second-degree entrance block of Mobitz type I. 1-3 Diagrams below the strips of Fig. 2 illustrate such second-degree entrance block. In the diagrams, shaded bars represent the long absolute refractory period in the pathway containing the parasystolic focus. The diagrams show that when a sinus impulse conducted to the RV (e.g., DS3 in the top strip) falls in the absolute refractory period of the pathway, the parasystolic focus is protected from this sinus impulse: On the other hand, From the Second Department of Medicine and the Department of Cardiovascular Medicine, Hokkaido University School of Medicine; and the Department of Medicine, Higashi Nippon Gakuen University School of Dentistry. Supported in part by a grant-in-aid for scientific research from the Ministry of Education, Science and Culture of the Japanese Government. Received for publication Oct. 17, 1980; revision received March 6, 1981; accepted March 30, 1981. Reprint requests: Shinji Kinoshita, M.D., the Second Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
0002-8703/81/080290 + 03500.30/0© 1981 The C. V. Mosby Co.
Fig. 1. Sinus beats showing type A Wolff-ParkinsonWhite (WPW) pattern and parasystolic beats resembling left bundle branch b l o c k pattern. Time intervals are expressed in hundredths of a second. DS = sinus beat; E = ectopic (parasystolic) beat.
when a conducted sinus impulse (e.g., DSll in the top strip) falls after the absolute refractory period of the pathway, it reaches and discharges the parasystolic focus after some delay, and then becomes a concealed reentrant ventricular extrasystole. After that, concealed reentrant bigeminal rhythm 3.4 continues until a parasystolic beat reappears. In Figs. 2 and 3, triple ventricular fusion beats are seen. In these fusion beats, the ventricles are simultaneously stimulated by three impulses of different origins: (1) an impulse coming through the accessory pathway and producing the delta wave (D), (2) a sinus impulse coming through the normal AV junction (S), and (3) an impulse coming from the ectopic (parasystolic) focus (E). The triple ventricular fusion beats have various configurations. These fusion beats can be classified into several groups. In the fusion beat EDS (the bottom strip of Fig, 3), impulse E invades the ventricles earlier than impulse D. In the fusion beat D/E S (Fig. 3), the impulses D and E invade the ventricles simultaneously, in which case the fusion beat shows a narrow QRS complex because the parasystolic focus and the preexcitation area of impulse D are situated in different ventricles. In the fusion beat DES (the bottom strip of Fig. 2), impulse E invades the ventricles later than impulse D, but earlier than impulse S. In the fusion beat DSE (the middle strip of Fig. 2), impulse E invades the ventricles later than impulse S. Prior to the present report, triple ventricular fusion in the WPW syndrome was noted in only a few patients with ventricular escape beats ~' or continuous ventricular parasystole." However, this is the initial report of triple ventricular fusion due to coexistence of the WPW syndrome with intermittent ventricular parasystole.
Volume
102
Number 2
Brief communications
Fig. 2. The WPW syndrome with intermittent ventricular parasystole due to second-degree entrance block of Mobitz type I, occasionally showing triple ventricular fusion. The top and middle strips are continuous. In the bottom strip sinus rhythm is slowed because of vagal stimulation. The numbers in the strips indicate intervals between a parasystolic beat and the following sinus beat. S h a d e d bars in the diagrams below the strips represent the absolute refractory period in the reentrant pathway containing the parasystolic focus. Vertical dashed lines in the diagrams represent intraventricular conduction of the sinus or parasystolic impulse leading to the reentrant pathway. ED, DES, and D S E = ventricular fusion beats; L V = left ventricle; R V = right ventricle; R P = reentrant pathway containing the parasystolic focus.
Fig. 3. Triple ventricular fusion beats showing various configurations. The first two strips are continuous. T h e numbers in the strips indicate intervals between a parasystolic beat and the following sinus beat. ED, EDS, D / E S, D E S , and D S E = ventricular fusion beats.
291
292
August 1981 American Heart Journal
Brief communications !
REFERENCES
1. Kinoshita S: Wenckebach phenomenon of entrance block in intermittent ventricular parasystole. Chest $6:530, 1974. 2. Kinoshita S: Intermittent parasystole originating in the reentrant path of ventricular extrasystoles. Chest 72:201, 1977. 3. Kinoshita S: Mechanisms of ventricular parasystole. Circulation 58:715, 1978. 4. Kinoshita S: Concealed ventricular extrasystoles due to interference and due to exit block. Circulation 52:230, 1975. 5. Myburgh DP, Carton J, Schamroth JM: Triple ventricular fusion in Wolff-Parkinson-White pattern. Chest 77:421, 1980. 6. Dubb A, Schamroth L: Ventricular parasystole with the Wolff-Parkinson-White syndrome. Chest 75:607, 1979.
Clinical comparison of indirectly and directly determined sinoatrial conducUon time Peter Rakovec, M.D., Ph.D., Japec Jakopin, M.D., Primo~ Rode, M.D., Miran F. Kenda, M.D., Ph.D., and M a t i j a Horvat, M.D., Ph.D. Ljubljana, Yugoslavia
Two methods of indirect estimation of sinoatrial node (SAN) conduction time (SACT) are c u r r e n t l y employed: (1) programmed p r e m a t u r e a t r i a l stimulation technique 1 and (2) modality utilizing a brief period of constant a t r i a l pacing. 2 While the l a t t e r m e t h o d is more simply and rapidly applied, it is subject to the same sources of error as those of the p r e m a t u r e a t r i a l stimulation technique. 3 Recently, a means of directly recording S A N electrical activity by endocardial catheterization has been described. 4 T h e purpose of this communication was to compare the new method of direct S A C T m e a s u r e m e n t 4 to an indirect method. ~ Such comparison is i m p o r t a n t because of the direct approach limitations,' which include low success rate and technical difficulty. Fifteen patients were studied who underwent temporary pacemaker electrode insertion because of dizziness and syncope. Their m e a n age was 59 years; six were men and nine were women. T h e patients had sick sinus syndrome (SSS) or AV block of different degree. After obtaining informed consent and without c o n c o m i t a n t cardioactive drugs, an electrode c a t h e t e r was passed via the right femoral vein or the left basilic vein a n d positioned at the superior vena cava-to-right a t r i a l junction. Bipolar S A N electrograms were recorded at paper speed 50 m m / s e c and high amplification 200 ~V/cm. Direct From the Cardiological Clinic and Center for Intensive Internal Medicine, Clinical Center, and Institute of Physiology, Medical Faculty. Received for publication Dec. 19, 1980; revision received March 23, 1981; accepted Apr. 3, 1981. Reprint requests: Dr. Peter Rakovec, Cardiological Clinic, Clinical Center, Zalo~ka 7, 61105 Ljubljana, Yugoslavia.
0002-8703/81/080292 + 03500.30/0 © 1981 The C. V. Mosby Co.
~CT Fig. 1. Record of S A N electrogram (SANE). Shown are the diastolic slope (A), the upstroke slope (B), and the primary negativity (C). Sinoatrial conduction time (SA CT) is measured from the point of departure of the upstroke slope from the t r a j e c t o r y of the diastolic slope to the beginning of the P wave in ECG lead II (voltage increased).
measurement of S A C T is shown in Fig. 1; indirectly S A C T was estimated by the constant atrial pacing technique. 2 Representative examples of both methods in a p a t i e n t with normal (Fig. 2) and in another p a t i e n t with prolonged (Fig. 3) S A C T are demonstrated. Mean value of directly measured SACT was 105 + 10 msec (SEM) and of indirectly estimated S A C T 117 _+ 12 msec; these mean values were not significantly different. The linear correlation coefficient between measured and estimated S A C T was 0.88 (p < 0.001) {Fig. 4). Estimation of S A C T by the indirect method exhibited a mean error of 16.5% when compared to the direct measurement. S A C T (measured by both methods) was prolonged ( > 120 msec) in all the five patients with SSS and in two patients with AV block. Experimental and clinical studies by Cramer et a12 and by H a l i m a n et al. 4' 6 have established the validity of directly obtained S A N recordings. Similar results were reported by Castillo Fenoy et al., 7 as well as by Rugienius and Steponeniene2 However, G r a n t et a12 compared estimates of S A C T obtained by constant atrial pacing to directly measured SACT in isolated rabbit right a t r i a l preparations; correlation between both values was satisfactory (r = 0.7) with 30% mean error of estimated SACT. While a greater discrepancy between indirectly and directly determined S A C T might have been anticipated, the study of G r a n t et al. 3 and our investigation reported herein document t h a t the indirect values of S A C T do n o t