A case of successful percutaneous transluminal septal myocardial ablation for heart failure due to severe left ventricular outflow obstruction with Mönckeberg's arteriosclerosis, manifested after aortic valvular replacement.

Although percutaneous transluminal septal myocardial ablation (PTSMA) has been the established treatment of symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM), the efficacy for specific HOCM is not elucidated. We report a successful case of PTSMA for heart failure with severe left ventricular outflow tract (LVOT) obstruction due to sigmoid-shaped interventricular septum and diffuse left ventricular hypertrophy with Mönckeberg's arteriosclerosis and aortic valvular stenosis. While the PTSMA relieved LVOT obstruction and symptoms in the acute phase, the modest recurrence was confirmed 6 months later, which is rare in the case of idiopathic HOCM. The possible mechanisms of LVOT obstruction and recurrence are discussed.

Comparison of five-year outcome of sirolimus-eluting stent implantation for chronic total occlusions versus for non-chronic total occlusion (from the j-Cypher registry).

The aim of this study was to evaluate the 5-year clinical outcomes of patients who underwent sirolimus-eluting stent implantation for chronic total occlusion (CTO). Among 10,759 patients treated exclusively with sirolimus-eluting stent in the j-Cypher registry, clinical outcomes were compared between 1,210 patients with revascularization for CTO and 9,549 patients with revascularization for non-CTO only. The cumulative 5-year incidence of all-cause death (13.2% vs 14.3%, p = 0.56) and definite stent thrombosis (1.9% vs 1.6%, p = 0.76) was similar between the 2 groups. The adjusted risk for CTO relative to non-CTO for all-cause death and definite stent thrombosis was insignificant (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.81 to 1.16, and HR 0.99, 95% CI 0.6 to 1.65, respectively). The cumulative incidence of target lesion revascularization was significantly higher in the CTO group (20.7% vs 14.8%, p <0.001). The adjusted risk for target lesion revascularization was significant (HR 1.31, 95% CI 1.13 to 1.52, p <0.001). In the subgroup analysis, the risk for CTO for all-cause death tended to be lower in the subgroup of patients with left ventricular ejection fractions ≤40% (HR 0.68, 95% CI 0.45 to 1.01, p = 0.053), while the risk was significantly higher in the subgroup of patients with end-stage renal disease without hemodialysis (HR 1.66, 95% CI 1.02 to 2.70, p = 0.04). In conclusion, sirolimus-eluting stent implantation for CTO appears to be as safe as that for non-CTO for up to 5 years, except for the modestly elevated risk for target lesion revascularization and the higher risk for all-cause death in patients with end-stage renal disease without hemodialysis.

A combination of two simultaneous tachycardias in the right atrium close to the atrio-ventricular node and within the coronary sinus in a post-operative cor triatriatum patient.

A 71-year-old male was referred to another hospital for dizziness. A bradycardia -tachycardia syndrome and Cor triatriatum were detected, and an operation to resect the membrane in the left atrium and implant a pacemaker epicardially was performed. However, no suitable site could be found on either atria and therefore, a single chamber ventricular pacemaker was implanted. In the electrophysiological study performed in our hospital, we could not detect any atrial potentials in either atria, excluding the region close to the His bundle (HB) and within coronary sinus (CS), in spite of extensive catheter mapping. A regular atrial rhythm with a cycle length of 820 ms, which was synchronous with the rate of the QRS complex on the surface ECG, was recorded only at the HB. Meanwhile, the CS catheter recording exhibited regular focal activity with a cycle length of 150 ms, and this focal activity did not conduct to the atrium close to the HB. Furthermore, this activity was dissociated from the ventricular activity recorded from the CS catheter. During an isoproterenol infusion, an atrial tachycardia with a cycle length of 380 ms was recorded only at the HB, and the twelve-lead ECG exhibited a regular tachycardia with the same cycle length as this tachycardia. Meanwhile, the focal activity within the CS persisted without any change in the cycle length. These findings suggested that there was dissociation between the right atrium (RA) and CS. Furthermore, partial atrial standstill was observed in both atria, excluding the RA close to the atrio-ventricular (AV) node and area within the CS. These rare electrophysiological features were considered to play an important role in the genesis of a simultaneous combination of the two tachycardias at their respective sites.

Changes in autonomic nervous activity after catheter ablation of atrial tachycardia arising from the atrioventricular annulus.

Radiofrequency (RF) catheter ablation of supraventricular tachycardias causes local parasympathetic denervation. This study used heart rate variability (HRV) to evaluate the effects of ablation of atrial tachycardia (AT) arising from the atrioventricular annulus (AVAT) on autonomic function. Ten patients with AVAT were referred for ablation (group AT) and compared with 8 patients with paroxysmal atrial fibrillation who underwent PV isolation (group Paf), and 13 patients with idiopathic ventricular tachycardia successfully treated by ablation (group VT). Time and frequency domain analysis of HRV on 24-hour ambulatory ECG recordings was performed before and after ablation. Root mean square of differences of consecutive N-N intervals (rMSSD), percentage of difference between consecutive N-N intervals >50 ms (pNN50), and high frequency (HF) component were measured to examine the effects on parasympathetic nerve activity. In group AT, rMSSD, pNN50, and HF decreased significantly after ablation, while they remained unchanged in group Paf and group VT. These observations suggest that parasympathetic denervation after ablation was limited to group AT, and depended on the site of energy delivery along the tricuspid or mitral valve as opposed to atrial or ventricular muscle.

Transient cerebral ischemic attack induced by transient left ventricular apical ballooning.

A 57-year-old woman had transient right hemiplegia 2 days after physical stress. An electrocardiogram exhibited T-wave inversion with QT prolongation. An echocardiogram revealed akinesia of the entire left ventricle except for the basal region. Cranial computed tomography and transthoracic echocardiography revealed an apical thrombus that disappeared 1 month later. Coronary angiography was normal. After 3 months, left ventricular wall motion had completely normalized.

Effect of left atrial-coronary sinus musculature connections on the coronary sinus activation pattern via retrograde conduction in patients with WPW syndrome.

BACKGROUND: Double potential (DP) activation patterns observed in coronary sinus (CS) electrograms recorded during left lateral atrial pacing, were explained by an initial low-frequency left atrial (LA) activation potential and secondary high-frequency CS musculature activation potential in canine hearts. Moreover, the connections between the LA and CS musculature vary greatly in size and location in the human heart. The purpose of this study was to investigate the relationship between the CS activation pattern during retrograde conduction via an accessory pathway (AP) and the location of left-sided APs. METHODS AND RESULTS: Fifty-one patients (31 males, mean age 48.6 years) who underwent radiofrequency catheter ablation of left-sided APs were divided into two groups according to the successful ablation site. The CS electrograms during retrograde AP conduction were classified into 3 types; single, fractionated, and DP activation patterns. A DP pattern was identified in 10 of 12 patients (83.3%) with posteroseptal to posterolateral APs, and in particular, 9 had a divergent sequence. Twenty-six of 39 patients (66.7%) with lateral to anterolateral APs, demonstrated a single pattern. The number of radiofrequency applications was significantly higher in patients with a DP pattern than in those with a single pattern (3.4 +/- 3.3 vs. 7.8 +/- 6.8, p < 0.01). CONCLUSION: Misleading information obtained when mapping for optimal ablation sites might result from DP patterns with a divergent sequence produced by discrete muscular connections between the LA and CS musculature. Ablation around left posterior APs may require meticulous observation of the CS activation patterns.

Electrophysiological features of atrial tachycardia arising from the atrioventricular annulus.

Atrial tachycardia (AT) arises from various sites in the atrium and the mechanisms are nonuniform. McGuire et al. reported that the cells around the atrioventricular annuli resembled nodal cells in their cellular electrophysiology. The purpose of this study was to delineate the electrophysiological features of AT arising from the atrioventricular (AV) annulus (AVAT). The study included five patients with six AVATs that were abolished by the radiofrequency energy delivery. The location of the AV annuli was defined by using the AV ratio of the local electrograms and the amplitude of the ventricular electrograms, in addition to the anatomic findings under fluoroscopic guidance. The tachycardia cycle lengths were 403 +/- 117 ms. An AV ratio of the electrograms at the successful ablation sites was 0.4 +/- 0.4 at the tricuspid annulus and 1.5 +/- 0.3 at the mitral annulus. Small doses (mean 3.2 +/- 1.8 mg) of adenosine triphosphate could terminate all the tachycardia episodes for five of the ATs without the development of AV nodal conduction block. The successful ablation sites were located at the right mid-septum in 1 AT, right posteroseptum in 2 ATs, right posterolateral region in 1 AT, and left anteroseptum in 2 ATs. These findings suggest that the cells with nodal-type action potentials around both annuli might play an important role in the genesis of AVAT.

Radiofrequency catheter ablation for intra-atrial reentrant tachycardia after surgery of atrial septal defect: use of isopotential mapping (QMS system) to demonstrate bidirectional complete block.

A 51 year-old Japanese man who had undergone surgical correction of an atrial septal defect at the age of 18 years old was referred to our institute for evaluation of his atrial arrhythmia. The conventional electrophysiological study was combined with a new technique utilizing an isopotential and isochronal mapping system (QMS) to visualize the electrical signals recorded with a 64-electrode basket catheter. Using this system, an intra-atrial reentrant tachycardia (IART) was demonstrated. The isopotential map recorded with the QMS (QMS-isoP) rapidly revealed a clockwise global reentrant circuit in the mid free wall of the right atrium and a narrowest activation isthmus between the lower end of the atriotomy scar and the inferior vena cava (IVC). After confirming entrainment with concealed fusion at the lower end of the atriotomy scar, radiofrequency energy was delivered linearly from this site to the IVC by slowly dragging the catheter. The elimination of the IART was defined by the QMS-isoP which demonstrated bidirectional block during pacing from both sides of the ablated linear lesion. The conventional technique of entrainment with concealed fusion combined with the QMS-isoP may result in a highly sophisticated method for identifying global reentrant circuits and for defining bidirectional block after eliminating the IART.

Idiopathic left ventricular aneurysm associated with pleomorphic ventricular tachycardia: a case report.

A 39-year-old Japanese woman presented with an idiopathic left ventricular aneurysm manifesting as recurrent episodes of palpitation. She was referred to our hospital for evaluation of sustained ventricular tachycardia. Echocardiography disclosed a dyskinetic well-defined wall bulge during both systole and diastole at the basal region of the interventricular septum, and reduced left ventricular wall thickness and severe hypokinesis at the anterolateral to posterolateral region. These appearances were confirmed by the angiographic findings. The sustained ventricular tachycardia was reproducibly induced by a single extrastimulus from the right ventricular apex. Subsequently, 4-type ventricular tachycardias were induced during the electrophysiological study and the mechanism of these ventricular tachycardias was considered reentry. Radiofrequency catheter ablation failed due to the changing QRS morphologies during the entrainment study. The patient was treated with cibenzoline 300 mg a day, and there has been no recurrence of tachycardia during the 18-month follow-up period.