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Gaetano Satullo - One of the best experts on this subject based on the ideXlab platform.
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Intermittent Sinus Bigeminy as an Expression of Sinus Parasystole: A Case Report
Journal of electrocardiology, 1999Co-Authors: Gaetano Satullo, Cavallaro LAbstract:A case of sinus Parasystole is reported. The diagnosis of sinus Parasystole is relatively difficult because there is no difference between the basic sinus P wave and the parasystolic wave. Sinus Parasystole is diagnosed according to the following electrocardiographic criteria: (1) premature P waves having contour identical to P waves of basic beats; (2) intervals between premature P waves mathematically related. In the case reported, the coupling intervals during long phases of intermittent sinus bigeminy were nearly fixed, because there was little variability in the returning cycles, making the diagnosis of sinus Parasystole difficult.
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Irregular sinus Parasystole due to intermittency and modulation of parasystolic activity.
Journal of cardiovascular electrophysiology, 1996Co-Authors: Gaetano Satullo, A Donato, Giuseppe Busà, Cavallaro LAbstract:Intermittent Sinus Parasystole. A case of intermittent sinus Parasystole in which the parasystolic focus is protected from the dominant sinus rhythm only during the second half of its intrinsic cycle is reported. In addition, a modulating (i.e., electrotonic) effect is often clearly exerted from the dominant rhythm upon the focus during the protected period. Coexistence of both modulation and intermittency in sinus Parasystole, as well as a modulating effect limited to the second part of the parasystolic cycle, have not been previously reported.
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Triple ventricular Parasystole
Journal of electrocardiology, 1993Co-Authors: Giuseppe Oreto, Gaetano Satullo, Francesco Luzza, Francesco SaporitoAbstract:This presentation reflects the analysis of an electrocardiographic recording obtained from a patient with hypertensive heart disease. In the initial section of the tracing, fixed coupled monomorphic ectopic ventricular beats occurred in regular trigeminal rhythm. The pattern changed following an atrial extrasystole and several ventricular ectopic beats of various configuration occurred, often in sequence. Analysis demonstrated the presence of three independent parasystolic rhythms, two of which manifested with the character of intermittency, namely they were occasionally reset by extraneous impulses. The interplay of the sinus pacemaker with three parasystolic foci resulted in a very complex arrhythmic pattern. In some periods, however, two out of three ectopic rhythms were inapparent, and the third one manifested with fixed coupled complexes, so that a regular extrasystolic trigeminy ensued, and Parasystole was not recognizable.
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Atrial Parasystole and Tachycardia: Modulation and Automodulation of a Parasystolic Focus
Chest, 1992Co-Authors: Gaetano Satullo, Francesco Luzza, A Donato, Francesco Saporito, Giuseppe OretoAbstract:This report deals with a patient reflecting atrial Parasystole and episodes of atrial tachycardia. The P' waves during tachycardia were identical to the parasystolic P' waves. Atrial Parasystole was at times regular, as revealed by a precise mathematical relationship between the interectopic intervals, and on other occasions irregular. Irregularity was due to modulation, namely electrotonic influence exerted by the sinus impulses upon the parasystolic focus. Atrial tachycardia occurred only during the periods when atrial Parasystole was modulated. Atrial tachycardia has been interpreted as due to automodulation, a situation where the propagated parasystolic impulse exerts an electrotonic influence on the ectopic focus itself, leading to a marked unexpected acceleration of the ensuing parasystolic discharge.
Giuseppe Oreto - One of the best experts on this subject based on the ideXlab platform.
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Triple ventricular Parasystole
Journal of electrocardiology, 1993Co-Authors: Giuseppe Oreto, Gaetano Satullo, Francesco Luzza, Francesco SaporitoAbstract:This presentation reflects the analysis of an electrocardiographic recording obtained from a patient with hypertensive heart disease. In the initial section of the tracing, fixed coupled monomorphic ectopic ventricular beats occurred in regular trigeminal rhythm. The pattern changed following an atrial extrasystole and several ventricular ectopic beats of various configuration occurred, often in sequence. Analysis demonstrated the presence of three independent parasystolic rhythms, two of which manifested with the character of intermittency, namely they were occasionally reset by extraneous impulses. The interplay of the sinus pacemaker with three parasystolic foci resulted in a very complex arrhythmic pattern. In some periods, however, two out of three ectopic rhythms were inapparent, and the third one manifested with fixed coupled complexes, so that a regular extrasystolic trigeminy ensued, and Parasystole was not recognizable.
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Atrial Parasystole and Tachycardia: Modulation and Automodulation of a Parasystolic Focus
Chest, 1992Co-Authors: Gaetano Satullo, Francesco Luzza, A Donato, Francesco Saporito, Giuseppe OretoAbstract:This report deals with a patient reflecting atrial Parasystole and episodes of atrial tachycardia. The P' waves during tachycardia were identical to the parasystolic P' waves. Atrial Parasystole was at times regular, as revealed by a precise mathematical relationship between the interectopic intervals, and on other occasions irregular. Irregularity was due to modulation, namely electrotonic influence exerted by the sinus impulses upon the parasystolic focus. Atrial tachycardia occurred only during the periods when atrial Parasystole was modulated. Atrial tachycardia has been interpreted as due to automodulation, a situation where the propagated parasystolic impulse exerts an electrotonic influence on the ectopic focus itself, leading to a marked unexpected acceleration of the ensuing parasystolic discharge.
Shinji Kinoshita - One of the best experts on this subject based on the ideXlab platform.
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Parasystole due to re-entry as the possible mechanism of ventricular Parasystole with second-degree entrance block.
Journal of cardiovascular medicine (Hagerstown Md.), 2010Co-Authors: Shinji Kinoshita, Takakazu Katoh, Hiroshi YoshidaAbstract:BACKGROUND In 1974, Kinoshita reported a case of 'irregular Parasystole' due to type I second-degree entrance block. Since then, many cases of such 'irregular' Parasystole have been reported by us. To explain the mechanism of 'irregular' Parasystole, two theories have been suggested, namely, 'electrotonic modulation' by Jalife and Moe, and 'type I second-degree entrance block' by us. On the contrary, in 1960, Kinoshita et al. reported a case of concealed bigeminy for the first time. The electrocardiographic findings in concealed bigeminy have suggested that there are dual re-entrant pathways with markedly long effective refractory periods in the re-entrant pathway. We have suggested that Parasystole may be caused by re-entry in such re-entrant pathways. In this article, attempts are made to explain the mechanism of all the electrocardiographic findings in our cases of Parasystole by 'Parasystole due to re-entry'. METHODS Using 24 studies on Parasystole and 21 studies on concealed extrasystoles that we have reported over 50 years, as well as three exemplary cases in this article, attempts are made to explain all electrocardiographic findings in Parasystole by 'Parasystole due to re-entry'. CONCLUSIONS The electrocardiographic findings in our previous clinical cases of Parasystole and concealed extrasystoles, as well as exemplary cases and diagrams in the present article, strongly suggest 'Parasystole due to re-entry' as the mechanism of ventricular Parasystole with second-degree entrance block.
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ventricular parasystolic couplets originating in the pathway between the ventricle and the parasystolic pacemaker mechanism of irregular Parasystole
Journal of Electrocardiology, 2001Co-Authors: Shinji Kinoshita, Takakazu Katoh, Takao Mitsuoka, Takashi Hanai, Yoshinori Tsujimura, Yoshihiko SasakiAbstract:Abstract This article explains the mechanism of “irregular” Parasystole. Two theories have been suggested: “electrotonic modulation” and “type I second degree entrance block.” This study attempts to clarify the mechanism of irregular Parasystole in cases of true ventricular Parasystole associated with ventricular parasystolic couplets. Cases associated with ventricular parasystolic couplets were selected from 37 clinical cases of true ventricular Parasystole in which one or more pure parasystolic cycles with no intervening nonectopic QRS complexes were found. Of the 37 cases of true ventricular Parasystole, ventricular parasystolic couplets were found in 4 cases. In none of the other 33 cases, ventricular parasystolic couplets were found. In all the cases coexisting with ventricular parasystolic couplets, the latter ectopic QRS complex of the couplet failed to reset the parasystolic rhythm. The above findings suggest that the latter ectopic QRS complex of the parasystolic couplet originated not in the parasystolic pacemaker but in the pathway between the ventricle and the parasystolic pacemaker. It seems that when a sinus impulse fell late in the parasystolic cycle, it passed through the site of second degree entrance block and that the parasystolic couplets originated from the reentrant pathway between the ventricle and the pacemaker. This strengthens our previous suggestion that the mechanism of irregular Parasystole is governed by “type I second degree entrance block” and not by “electrotonic modulation.”
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Ventricular parasystolic couplets originating in the pathway between the ventricle and the parasystolic pacemaker: Mechanism of “irregular” Parasystole☆
Journal of electrocardiology, 2001Co-Authors: Shinji Kinoshita, Takakazu Katoh, Takao Mitsuoka, Takashi Hanai, Yoshinori Tsujimura, Yoshihiko SasakiAbstract:Abstract This article explains the mechanism of “irregular” Parasystole. Two theories have been suggested: “electrotonic modulation” and “type I second degree entrance block.” This study attempts to clarify the mechanism of irregular Parasystole in cases of true ventricular Parasystole associated with ventricular parasystolic couplets. Cases associated with ventricular parasystolic couplets were selected from 37 clinical cases of true ventricular Parasystole in which one or more pure parasystolic cycles with no intervening nonectopic QRS complexes were found. Of the 37 cases of true ventricular Parasystole, ventricular parasystolic couplets were found in 4 cases. In none of the other 33 cases, ventricular parasystolic couplets were found. In all the cases coexisting with ventricular parasystolic couplets, the latter ectopic QRS complex of the couplet failed to reset the parasystolic rhythm. The above findings suggest that the latter ectopic QRS complex of the parasystolic couplet originated not in the parasystolic pacemaker but in the pathway between the ventricle and the parasystolic pacemaker. It seems that when a sinus impulse fell late in the parasystolic cycle, it passed through the site of second degree entrance block and that the parasystolic couplets originated from the reentrant pathway between the ventricle and the pacemaker. This strengthens our previous suggestion that the mechanism of irregular Parasystole is governed by “type I second degree entrance block” and not by “electrotonic modulation.”
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Effects of exercise and standing on atrial Parasystole: Prolongation and shortening of the parasystolic cycle length
Journal of electrocardiology, 1999Co-Authors: Shinji Kinoshita, Yohtaro Oyama, Hisao Kawasaki, Shuichi KinoshitaAbstract:In recently reported cases of ventricular Parasystole, it was shown that after exercise the parasystolic cycle length is prolonged, in contrast to a shortening of the sinus cycle length, whereas during standing the parasystolic cycle length and the sinus cycle length both shortened. In this report, to explore whether the same features as occur in ventricular Parasystole are seen in atrial Parasystole, effects of exercise and standing on the parasystolic cycle length were investigated in two men with atrial Parasystole. The atrial parasystolic cycle length was prolonged after exercise, whereas it shortened during standing, similar to what occurs in ventricular Parasystole. This is the first report to show such changes of cycle length in atrial Parasystole. These findings suggest that in atrial Parasystole, as in ventricular Parasystole, influences on the parasystolic cycle length do not always act in the same direction as those on sinus cycle length.
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Differentiation between Parasystole and extrasystoles. Influence of vagal stimulation on parasystolic impulse formation.
Journal of electrocardiology, 1994Co-Authors: Shinji Kinoshita, Go Konishi, Fumihiko Okada, Makoto Kinoshita, Yoshito ItoAbstract:Recently, it has been shown that when a sinus impulse falls late in the parasystolic cycle, it usually hastens the next ectopic discharge. Thus, in many cases, the classic criteria for the diagnosis of Parasystole (ie, varying coupling intervals and constant shortest interectopic intervals) cannot be used. To differentiate between Parasystole and extrasystoles in such cases, the influence of vagal stimulation on parasystolic impulse formation was investigated in seven cases of "true" Parasystole in which one or more "pure" ectopic cycles without any intervening nonectopic QRS complexes were found spontaneously. In all cases pure ectopic cycles were found during sinus arrest caused by vagal stimulation; namely, none of the cases showed extreme prolongation of the parasystolic cycle. These results strongly suggest that instead of the classic criteria, vagal stimulation causing temporary sinus arrest is the optimal method for differentiation between Parasystole and extrasystoles in cases without spontaneous pure ectopic cycles.
Lihong Wang - One of the best experts on this subject based on the ideXlab platform.
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Ablation of unmappable ventricular Parasystole originating from the right ventricular outflow tract: a case report
BMC cardiovascular disorders, 2019Co-Authors: Huan Wang, Lihong WangAbstract:When the coupling interval is matched, ventricular Parasystole can form a stable fusion QRS complex with sinus rhythm. Ablation of a fusion QRS complex has been rarely reported and is unexpectedly difficult. We describe a case of ventricular Parasystole from muscle sleeves of the right ventricular outflow tract. The patient was a 54-year-old woman who was admitted to the hospital because of frequent palpitations for 3 months. Anti-arrhythmic drugs had been ineffective, and she had no history of cardiovascular disease. Because the fusion QRS complex interfered with the conventional mapping technique, we could not eliminate the ventricular Parasystole successfully. Finally, we used the reversed U curve method and found that the source of ventricular arrhythmia was in the right cusp according to the special local potential. A fusion QRS complex formed by ventricular Parasystole and nodal ventricular activation make mapping and ablation difficult. The special local potential was the only evidence available to confirm the target of ablation satisfactorily.
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Ablation of unmappable ventricular Parasystole originating from the right ventricular outflow tract: a case report
BMC, 2019Co-Authors: Huan Wang, Lihong WangAbstract:Abstract Background When the coupling interval is matched, ventricular Parasystole can form a stable fusion QRS complex with sinus rhythm. Ablation of a fusion QRS complex has been rarely reported and is unexpectedly difficult. Case presentation We describe a case of ventricular Parasystole from muscle sleeves of the right ventricular outflow tract. The patient was a 54-year-old woman who was admitted to the hospital because of frequent palpitations for 3 months. Anti-arrhythmic drugs had been ineffective, and she had no history of cardiovascular disease. Because the fusion QRS complex interfered with the conventional mapping technique, we could not eliminate the ventricular Parasystole successfully. Results and conclusions Finally, we used the reversed U curve method and found that the source of ventricular arrhythmia was in the right cusp according to the special local potential. A fusion QRS complex formed by ventricular Parasystole and nodal ventricular activation make mapping and ablation difficult. The special local potential was the only evidence available to confirm the target of ablation satisfactorily
Francesco Saporito - One of the best experts on this subject based on the ideXlab platform.
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Triple ventricular Parasystole
Journal of electrocardiology, 1993Co-Authors: Giuseppe Oreto, Gaetano Satullo, Francesco Luzza, Francesco SaporitoAbstract:This presentation reflects the analysis of an electrocardiographic recording obtained from a patient with hypertensive heart disease. In the initial section of the tracing, fixed coupled monomorphic ectopic ventricular beats occurred in regular trigeminal rhythm. The pattern changed following an atrial extrasystole and several ventricular ectopic beats of various configuration occurred, often in sequence. Analysis demonstrated the presence of three independent parasystolic rhythms, two of which manifested with the character of intermittency, namely they were occasionally reset by extraneous impulses. The interplay of the sinus pacemaker with three parasystolic foci resulted in a very complex arrhythmic pattern. In some periods, however, two out of three ectopic rhythms were inapparent, and the third one manifested with fixed coupled complexes, so that a regular extrasystolic trigeminy ensued, and Parasystole was not recognizable.
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Atrial Parasystole and Tachycardia: Modulation and Automodulation of a Parasystolic Focus
Chest, 1992Co-Authors: Gaetano Satullo, Francesco Luzza, A Donato, Francesco Saporito, Giuseppe OretoAbstract:This report deals with a patient reflecting atrial Parasystole and episodes of atrial tachycardia. The P' waves during tachycardia were identical to the parasystolic P' waves. Atrial Parasystole was at times regular, as revealed by a precise mathematical relationship between the interectopic intervals, and on other occasions irregular. Irregularity was due to modulation, namely electrotonic influence exerted by the sinus impulses upon the parasystolic focus. Atrial tachycardia occurred only during the periods when atrial Parasystole was modulated. Atrial tachycardia has been interpreted as due to automodulation, a situation where the propagated parasystolic impulse exerts an electrotonic influence on the ectopic focus itself, leading to a marked unexpected acceleration of the ensuing parasystolic discharge.
