Comprehension of active, passive, and causative sentences by Japanese-speaking children with intellectual disabilities and typical development.

This study aimed to identify the comprehension strategies employed for active, passive, and causative sentences and the involvement of phonological memory, which is a subsystem of working memory, in the comprehension skills of Japanese-speaking children with intellectual disability (ID) compared to those with typical development (TD). The participants were 29 children with ID and 18 children with TD who were matched according to mental and vocabulary ages and phonological memory scores. A picture selection method was employed as a sentence comprehension task. The stimulus sentences were grouped into four patterns of word order: subject (S) - object (O) - verb (V), OSV, SV, and OV. For example, in active sentences, the subject and object are assigned to agent and patient, respectively. The results indicated that children in both groups made comprehension errors for sentences that lacked information regarding the agent and sentences in which the two-noun sequence inverts the typical agent - patient or instructor - instructed order. Phonological memory's involvement in sentence comprehension varied according to the combination of participant groups, sentence types, and patterns. The results suggest that both children with ID and TD relied on agent bias, whereby children consider the first noun to denote the actor and a word order strategy of interpreting a sequence of two noun phrases followed by the transitive verb as agent - patient - act. Furthermore, phonological memory underpins understanding of the relationships among arguments, particularly in the case of sentences for which agent bias or word order strategy may result in misinterpretation.

Paradoxical Brain Emboli Related to Heparin-Induced Thrombocytopenia after Catheter Ablation.

BACKGROUND: Thromboembolism associated with catheter ablation of atrial fibrillation has been considered to be derived from catheters, ablation sites, or a left atrial appendage. Paradoxical brain embolism due to iatrogenic shunt after catheter ablation has yet to be described. METHODS: We described a patient with atrial fibrillation who developed acute ischemic stroke while coughing 36 hours after successful catheter ablation. He had venous thrombosis due to heparin-induced thrombocytopenia and a right-to-left shunt, likely due to a trans-septal puncture during catheter ablation. RESULTS: The final diagnosis was paradoxical brain embolism associated with heparin-induced thrombocytopenia. CONCLUSIONS: In addition to anticoagulation, we should pay attention to deep venous thrombosis including preventive intermittent compression for high-risk patients to reduce the risk of stroke after catheter ablation.

Complex anatomy surrounding the left atrial posterior wall: analysis with 3D computed tomography.

Few studies have explored the topographic anatomy of the esophagus, posterior wall of the left atrium (LA), or fat pads using multidetector computed tomography (MDCT) to prevent the risk of esophageal injury during atrial fibrillation (AF) ablation. MDCT was performed in 110 consecutive patients with paroxysmal or persistent AF before the ablation procedure to understand the anatomic relationship of the esophagus. Two major types of esophagus routes were demonstrated. Leftward (type A) and rightward (type B) routes were found in 90 and 10% of the patients, respectively. A type A route had a larger mean size of the LA than type B. The fat pad was identifiable at the level of the inferior pulmonary vein in 91% of the patients without any predominance of either type. The thickness of the fat pad was thinner in the patients with a dilated LA (>42 mm) than in those with a normal LA size (≤42 mm) (p = 0.01). The results demonstrated that the majority of cases had a leftward route of the esophagus. There was a close association between the LA dilatation and fat pad thinning. With a dilated LA, the esophagus may become easily susceptible to direct thermal injury during AF ablation. Visualization of the anatomic relationship may contribute to the prevention of the potential risk of an esophageal injury.

Catheter ablation of ventricular arrhythmias arising from the right ventricular septum close to the His bundle: features of the local electrogram at the optimal ablation site.

INTRODUCTION: The characteristics of the local electrogram at the optimal ablation site of ventricular arrhythmias (VAs) originating from the right ventricle close to the His bundle (HB) region have rarely been described. METHODS AND RESULTS: Among 190 consecutive patients with idiopathic VAs with left bundle branch block morphology and inferior-axis deviation, 16 were found to have successful ablation site in the right ventricle close to the HB region (para-Hisian group). The electrophysiologic data were compared between the patients in the para-Hisian group and those with VAs arising from the right ventricular (RV) outflow tract (RVOT group). The distal bipolar electrogram at the successful ablation sites in the para-Hisian group exhibited a significantly greater R-wave duration, lower R-wave amplitude, and slower upright deflection of the initial R wave than did those in the RVOT group (all P < 0.001). In the para-Hisian group, a total of 56 radiofrequency (RF) energy applications were delivered, of which the local electrograms at 16 successful and 40 unsuccessful ablation sites were reviewed. High-frequency R-wave potentials of the bipolar electrogram were present in 14 (88%) of the successful ablation sites. An R-wave duration of greater than 34 ms had a discriminatory power for indicating the site of a successful ablation (area under the receiver-operator characteristics curve 0.90, sensitivity 94%, specificity 80%). CONCLUSIONS: The successful ablation site of the para-Hisian VAs had distinctive local electrogram characteristics. A longer R-wave duration of the bipolar electrogram with high-frequency potentials could be a novel predictor of a successful ablation.

Atrial defibrillation threshold as a novel predictor of clinical outcome of catheter ablation for persistent atrial fibrillation.

AIMS: Catheter ablation for persistent atrial fibrillation (AF) is currently performed with different procedural endpoints. When AF did not terminate during ablation procedure, electrical cardioversion was performed at different defibrillation threshold (DFT) according to AF characteristics and atrial electrophysiologic substrates. We sought to evaluate the impact of atrial DFT after catheter ablation for persistent AF on clinical outcome. METHODS AND RESULTS: We studied 128 patients with persistent AF (age 63±9 years, 106 men). After completion of circumferential pulmonary vein isolation, the left atrial substrate ablation was performed until AF terminated or all identified complex fractionated electrograms were eliminated. If AF did not terminate during ablation, an internal cardioversion protocol was started at 5J and was increased incrementally in 5 J steps until successful cardioversion was accomplished. Procedural AF termination was achieved in 50 patients (Group A). Atrial fibrillation was terminated by cardioversion with DFT≤10 J in 47 patients (Group B) and with DFT>10 J in 31 patients (Group C). At 14±7 follow-up months after 1.3±0.5 sessions, 47 (94%) Group A patients, 42 (89%) Group B patients, and 14 (45%) Group C patients remained in sinus rhythm. In multivariate analysis of Group B and Group C, DFT (hazard ratio 5.54, P<0.001) and AF duration (hazard ratio 3.74, P=0.011) were independent predictors of recurrent arrhythmia. CONCLUSION: When AF does not terminate after the completion of predetermined stepwise ablation, further extensive ablation to terminate AF might be unnecessary if the AF can be successfully terminated by electrical cardioversion at low DFT.

No severe pulmonary vein stenosis after extensive encircling pulmonary vein isolation: 12-month follow-up with 3D computed tomography.

Few studies have explored the utility of local electrogram-guided extensive encircling pulmonary vein isolation (EEPVI) by analyzing the pulmonary vein (PV) anatomy and occurrence of stenosis using multidetector computed tomography (MDCT). One hundred seventy-six paroxysmal atrial fibrillation (AF) patients underwent EEPVI with a double lasso technique. MDCT was performed in all patients before and at 3, 6 and 12 months after the ablation procedures to screen for PV stenosis. PV stenosis was defined as a >30% reduction in its diameter. A total of 700 PVs were analyzed. PV stenosis was observed in 15 of 700 PVs (2.1%). All stenoses were mild (mean 34.5 ± 3.3%). They were all asymptomatic, and none required treatment. After 12 months of follow-up, the PV narrowing regressed significantly compared with that at 3 months in the patients with PV stenosis (34.5 ± 3 to 30.4 ± 5%, P < 0.05). The remaining PVs exhibited a stable anatomy, and there was no significant progression of the PV narrowing. The results of this study demonstrated that detectable PV stenosis occurred in 2.1% of the PVs, and all stenoses were mild. Moreover, a significant regression of the PV narrowing was observed after 12-months of follow-up. This indicates that the local electrocardiogram-guided EEPVI was relatively safe regarding severe PV stenosis.

Simultaneous conduction over the fast and slow pathways during induction of atrioventricular nodal reentrant arrhythmia with a rate of less than 100 bpm and infra-His block after radiofrequency ablation of the slow pathway.

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common form of paroxysmal regular supraventricular tachycardia in adults. It is typically induced with an anterograde block over the fast pathway (FP) and conduction over the slow pathway (SP), with subsequent retrograde conduction over the FP. Rarely, a simultaneous conduction of a premature atrial complex occurs over the FP and SP to induce AVNRT and is called "one for two phenomenon". We present a 46-year-old woman with atrioventricular nodal rhythm with a rate of 95 beats per minute with distinct electrophysiological characteristics showing simultaneous conduction over the FP and SP during induction of tachycardia and an infra-His block after radiofrequency ablation of the SP.

Some issues of Japanese speech-language-hearing therapy education.

Recent trends in Japanese speech-language-hearing (SLH) therapy education are reported. The rapid growth of educational institutions has continued since our last report. The educational curriculum was established by the 1997 certification of Japanese SLH therapists, and is strictly applied to educating both college/university and vocational school students. Over 1,000 students annually become registered SLH therapists, of whom nearly 70% are under the age of 39 years. More therapists are employed full time to serve the adult population, while a limited number of therapists are fully employed to provide services to children. As a member of the economically more advanced nations, Japan receives assistance from foreign workers coming from economically less developed nations. Their children face the difficult tasks of learning both their mother tongue and Japanese. There is a strong need for our profession to assist the early language acquisition of these children because their cognitive and personal development will be greatly influenced by adequate language acquisition. An appeal is made to our colleagues for sharing the mutual tasks of bringing about better linguistic and communicative development in those educationally disadvantaged children.

"Left-variant" adenosine-sensitive atrial reentrant tachycardia ablated from the left coronary aortic sinus.

Adenosine-sensitive reentrant atrial tachycardia (AT) is usually amenable to ablation at the right superoseptum near the His bundle. We report a case with "left-variant" adenosine-sensitive reentrant AT. The AT was reproducibly induced by atrial extrastimulation with negative correlation between the coupling interval and return cycle, and was terminated by atrial extrastimulation and bolus of 2 mg of adenosine 5'-triphosphate. Ablations at the right superoseptum were unsuccessful; however, the AT was successfully ablated from the left coronary aortic sinus (LCAS) where the earliest atrial activation was recorded. Ablation at the LCAS might be effective in this entity resistant to right-sided ablation.

Superior type of atypical AV nodal reentrant tachycardia: incidence, characteristics, and effect of slow pathway ablation.

BACKGROUND: Atypical atrioventricular (AV) nodal reentrant tachycardias (AVNRT) usually exhibit the earliest retrograde atrial activation (ERAA) at the right inferoseptum (Rt-IS) or proximal coronary sinus (PCS). The purpose of this study was to characterize atypical AVNRT with the ERAA at the right superoseptum (Rt-SS). METHODS: Seventy-three atypical AVNRTs induced in 63 cases were classified into the superior type with the ERAA at the Rt-SS and inferior type with the ERAA at the Rt-IS or PCS. RESULTS: There were nine superior (12%) and 64 inferior types of atypical AVNRT (88%) in seven and 56 cases, respectively. The superior type exhibited a short atrial-His interval during the tachycardia (166 +/- 41 ms), long His-atrial interval during the tachycardia (H-At:156 +/- 38 ms), and ventricular pacing at the tachycardia cycle length (TCL) (H-Ap:201 +/- 36 ms), and evidence for a lower common pathway, including second-degree AV block (four tachycardias) and an H-Ap being longer than the H-At (nine tachycardias). The TCL was shorter in the superior type than in the inferior type (322 +/- 35 vs 404 +/- 110 ms; P < 0.02). In the inferior type, all tachycardias were eliminated after the ablation at the Rt-IS (44 tachycardias) or PCS (20 tachycardias) where an ERAA was recorded. In the superior type, ablation at the Rt-IS was ineffective; however, ablation at the right midseptum eliminated seven (78%) of the nine tachycardias. CONCLUSIONS: The tachycardia circuit of the superior type might have deviated to a more superior part of Koch's triangle than that of the inferior type.

Shift in the earliest retrograde atrial activation site during the fast-slow form of atrioventricular nodal reentrant tachycardia after the radiofrequency modification of the atrioventricular node: is the atrium a necessary link?

Whether or not the perinodal atrium forms an upper link in the tachycardia circuit of the atypical form of AV nodal reentrant tachycardia (AVNRT) is controversial. We report a case with the fast-slow form of AVNRT in whom the earliest retrograde atrial activation site during the tachycardia changed from the right inferoseptum to the right superoseptum close to the His bundle without a change in the tachycardia cycle length following the radiofrequency energy applications to the earliest retrograde atrial activation site. It was speculated that a sub-atrial reentry with multiple atrial breakthroughs was the possible tachycardia mechanism in the present case.

Atypical atrioventricular nodal reentrant tachycardia with eccentric coronary sinus activation: electrophysiological characteristics and essential effects of left-sided ablation inside the coronary sinus.

BACKGROUND: The precise electrophysiological characteristics and essential effects of left-sided ablation in atrioventricular nodal reentrant tachycardia (AVNRT) with eccentric coronary sinus (CS) activation (ECSA) have not been described. OBJECTIVE: The purpose of this study was to elucidate the tachycardia characteristics and essential effects of left-sided ablation in AVNRT with ECSA. METHODS: Electrophysiological and ablation data were reviewed in 340 patients with all forms of AVNRT. RESULTS: Among 360 AVNRTs in the 340 patients, there were 23 atypical AVNRTs (6%; 12 slow-slow and 11 fast-slow) in 18 (5%) patients who exhibited ECSA with the earliest retrograde atrial activation 11 +/- 5 mm inside the CS. The patients with ECSA during the tachycardia were significantly younger than those without (38 +/- 18 vs. 51 +/- 18 years; P<.01). The presence of upper (UCP) and lower common pathways (LCP) was suggested in three (17%) and 18 (100%) patients, respectively. An ablation exclusively targeting the earliest retrograde atrial activation inside the CS eliminated the tachycardias with the elimination (n = 12) or modification of the left-sided slow pathway (SP) conduction (n = 6) without any complications. The entire reentrant circuit was considered to reside on the left side in two patients (11%) because the bidirectional SP conduction was simultaneously eliminated after the ablation inside the CS. CONCLUSIONS: Atypical AVNRT with ECSA involved the left-sided SP as a retrograde limb, and the reentrant circuit was more frequently associated with evidence that suggested a UCP and LCP. Ablation exclusively targeting the earliest retrograde atrial activation inside the CS was highly effective in this entity.

Irregular atypical atrioventricular nodal reentrant tachycardia: incidence, electrophysiological characteristics, and effects of slow pathway ablation.

BACKGROUND: Atrioventricular (AV) nodal reentrant tachycardias (AVNRT) with variable AV relationships are infrequently observed and might be misdiagnosed as atrial tachycardia. OBJECTIVE: This single-center, retrospective study was performed to elucidate the mechanism of AVNRT showing variable AV relationship. METHODS: This study included a total of 340 patients with all forms of AVNRT. The induced AVNRTs were classified into those with variations in the AV relationship (>or=30 ms) (irregular AVNRT) and those without (regular AVNRT). RESULTS: A total of 364 AVNRTs (typical and atypical form = 297 and 67) were induced in the 340 patients. Of the 364 AVNRTs, the variations in the AV relationship were observed in 8 atypical AVNRTs (2%) induced in 8 patients (2%). The patients with irregular atypical AVNRT were significantly younger than those with regular typical AVNRT and those with regular atypical AVNRT (35+/-15 vs 51+/-18 and 47+/-16 years, respectively). Irregular atypical AVNRTs showed atypical Wenckebach periodicity with simultaneous prolongation in the A-A intervals and Wenckebach block proximal to the His bundle. Irregular atypical AVNRTs showed a shorter tachycardia cycle length (TCL) (305+/-78 ms vs 381+/-95 ms; P<.05) and higher prevalence of eccentric coronary sinus (CS) activation than regular atypical AVNRTs (5 (63%) of 8 tachycardias vs 15 (25%) of 59 tachycardias; P<.05). An ablation applied to the earliest retrograde activation sites (CS and right inferoseptum = 5 and 3 cases, respectively) eliminated all irregular atypical AVNRTs. CONCLUSION: The variations in the AV relationship were observed exclusively during atypical AVNRT in 2% of all AVNRT cases. Irregular atypical AVNRT was characterized by younger age of the patients and shorter TCL, and it more frequently required an ablation inside the CS for success. We postulate that the noted irregularity was attributable to the short TCL that gave rise to the unstable conduction in the tachycardia circuit and Wenckebach block in the lower common pathway.

Participation of a concealed atriohisian tract in the reentrant circuit of the slow-fast type of atrioventricular nodal reentrant tachycardia.

BACKGROUND: The retrograde fast pathway in typical atrioventricular nodal reentrant tachycardia (AVNRT) exhibits marked variation in its electrophysiologic properties. OBJECTIVE: The purpose of this study was to characterize the retrograde fast pathway and localize the lower turnaround site of the reentrant circuit in typical AVNRT. METHODS: Seventy-four patients with typical AVNRT were divided into two groups according to the response of the retrograde fast pathway to intravenous administration of adenosine triphosphate (ATP) during ventricular pacing: ATP-S [n = 47 (63.5%)] with and ATP-R without [n = 27 (36.5%)] His-atrial (H-A) block. H-A intervals were measured from the most proximal His-bundle electrogram to the earliest atrial activation during the tachycardia (HAt) and entrainment pacing from the parahisian right ventricular region (HAe). It was postulated that the HAt was the difference in conduction time between the lower common pathway (x) and retrograde fast pathway (y) (HAt = y - x), whereas HAe was the sum of the two (HAe = y + x). Hence, x = (HAe-HAt)/2. x >0 suggested the presence of a lower common pathway, whereas x <0 suggested the absence of a lower common pathway and lower turnaround site within the His bundle. RESULTS: x was significantly smaller in ATP-R than ATP-S (-6 +/- 5 vs 4 +/- 4 ms, P <.05) and was <0 in 23 (85%) of 27 ATP-R patients. The maximal increment in H-A interval during ventricular pacing was significantly longer in ATP-S than ATP-R (35 +/- 33 vs 2 +/- 2 ms, P <.05). CONCLUSION: A concealed atriohisian tract totally bypassing the atrioventricular node constituted the retrograde fast pathway in one third of all typical AVNRT cases.

Catheter ablation therapy for atrial fibrillation: current advancements in strategies.

Curing atrial fibrillation (AF) by catheter ablation has significantly improved patient morbidity and mortality. The circumferential pulmonary vein isolation technique is established as the principal procedure, with a high cure rate and acceptable safety, for paroxysmal AF, but new adjunctive ablation strategies targeting the AF substrates and sources for long-standing persistent/chronic AF have been developed. These new techniques include linear ablation, complex fractionated atrial electrogram guided ablation, dominant frequency map-guided ablation, ganglionated plexi ablation and disconnection of the coronary sinus and superior vena cava to ablate the AF substrates and sources. The long-term usefulness of the established technique and these innovative adjunctive approaches for the treatment of AF remains to be investigated.

Implications of 2:1 atrioventricular block during typical atrioventricular nodal reentrant tachycardia.

OBJECTIVE: The effects of 2:1 AV block (AVB) on AV nodal reentrant tachycardia (AVNRT) remain to be elucidated. This study was performed to localize the site of 2:1 AVB and elucidate the effects of 2:1 AVB on typical AVNRT. METHODS: The His bundle (HB) electrograms during typical AVNRT with 2:1 AV block were reviewed in 24 patients. It was hypothesized that if 2:1 AVB at the HB or below changed tachycardia cycle length (TCL), the lower turnaround point of the reentrant circuit (RC) might be located within the HB and parts of the HB might be involved in the RC. RESULTS: A HB potential was absent in blocked beats during 2:1 AVB in four patients (supra-Hisian block), and the maximal amplitude of the HB potential in blocked beats was the same as that in conducted beats in four patients (infra-Hisian block), and was significantly smaller than that in conducted beats (0.1 +/- 0.1 versus 0.5 +/- 0.2 mV, P < 0.05) in 16 patients (intra-Hisian block). Eight patients (33%) with intra-Hisian block had a nearly identical prolongation of the H-A and A-A intervals in blocked beats (12 +/- 3 and 13 +/- 2 ms, respectively) with unchanged A-H intervals, while the remaining 16 patients (67%) exhibited invariable A-A and/or H-A intervals. CONCLUSION: The site of 2:1 AVB during typical AVNRT was estimated to be at the HB or below in 83% of the cases. Two-to-one intra-Hisian block transiently prolonged TCL, possibly indicating involvement of the proximal HB in the RC in one-third of typical the AVNRT cases with 2:1 AVB.

"Left-variant" atypical atrioventricular nodal reentrant tachycardia: electrophysiological characteristics and effect of slow pathway ablation within coronary sinus.

INTRODUCTION: Recent anatomical and electrophysiological studies have demonstrated the presence of leftward posterior nodal extension (LPNE); however, its role in the genesis of atrioventricular nodal reentrant tachycardia (AVNRT) is poorly understood. This study was performed to characterize successful slow pathway (SP) ablation site and to elucidate the role of LPNE in genesis of atypical AVNRT with eccentric activation patterns within the coronary sinus (CS). METHODS AND RESULTS: Among 45 patients with atypical AVNRT (slow-slow/fast-slow/both = 20/22/3 patients) with concentric (n = 37, 82%) or eccentric CS activation (n = 8, 18%), successful ablation site was evaluated. Among 35/37 patients (95%) with concentric CS activation, ablation at the conventional SP region outside CS eliminated both retrograde SP conduction and AVNRT inducibility. Among eight patients with eccentric CS activation, the earliest retrograde atrial activation was found at proximal CS 16 +/- 4 mm distal to the ostium during AVNRT. The earliest retrograde activation site was located at inferior to inferoseptal mitral annulus, consistent with the presumed location of LPNE. Ablation at the conventional SP region with electroanatomical approach only rendered AVNRT nonsustained without elimination of retrograde SP conduction in seven of eight patients (88%). Ablation targeted to the earliest retrograde atrial activation site within proximal CS (15 +/- 4 mm distal to the ostium); however, eliminated retrograde SP conduction and rendered AVNRT noninducible in six of eight patients (75%). CONCLUSION: In 75% of "left-variant" atypical AVNRT, ablation within proximal CS was required to eliminate eccentric retrograde SP conduction and render AVNRT noninducible, suggesting LPNE formed retrograde limb of reentrant circuit.

Unique electrophysiologic characteristics of atrioventricular nodal reentrant tachycardia with different ventriculoatrial block patterns: effects of slow pathway ablation and insights into the location of the reentrant circuit.

BACKGROUND: The electrophysiologic mechanisms of different ventriculoatrial (VA) block patterns during atrioventricular nodal reentrant tachycardia (AVNRT) are poorly understood. OBJECTIVES: The purpose of this study was to characterize AVNRTs with different VA block patterns and to assess the effects of slow pathway ablation. METHODS: Electrophysiologic data from six AVNRT patients with different VA block patterns were reviewed. RESULTS: All AVNRTs were induced after a sudden AH "jump-up" with the earliest retrograde atrial activation at the right superoparaseptum. Different VA block patterns comprised Wenckebach His-atrial (HA) block (n = 4), 2:1 HA block (n = 1), and variable HA conduction times during fixed AVNRT cycle length (CL) (n = 1). Wenckebach HA block during AVNRT was preceded by gradual HA interval prolongation with fixed His-His (HH) interval and unchanged atrial activation sequence. AVNRT with 2:1 HA block was induced after slow pathway ablation for slow-slow AVNRT with 1:1 HA conduction, and earliest atrial activation shifted from right inferoparaseptum to superoparaseptum without change in AVNRT CL. The presence of a lower common pathway was suggested by a longer HA interval during ventricular pacing at AVNRT CL than during AVNRT (n = 5) or Wenckebach HA block during ventricular pacing at AVNRT CL (n = 1). In four patients, HA interval during ventricular pacing at AVNRT CL was unusually long (188 +/- 30 ms). Ablations at the right inferoparaseptum rendered AVNRT noninducible in 5 (83%) of 6 patients. CONCLUSION: Most AVNRTs with different VA block patterns were amenable to classic slow pathway ablation. The reentrant circuit could be contained within a functionally protected region around the AV node and posterior nodal extensions, and different VA block patterns resulted from variable conduction at tissues extrinsic to the reentrant circuit.