-
Yukoh Hirai,
Yukiko Nakano,
Hideya Yamamoto,
Hiroshi Ogi,
Yoshiyuki Yamamoto,
Kazuyoshi Suenari,
Noboru Oda, Shigeyuki Ueda,
Yuko Makita,
Kenta Kajihara,
Yasuki Kihara
[show abstract]
[hide abstract]
ABSTRACT: Background: Distinguishing left-and right-sided atrial tachycardia (AT) is often challenging. The coronary sinus (CS) provides information only concerning the anterior left atrium (LA). Potentials recorded in the pulmonary artery (PA) have been substituted for those of the upper posterior LA because of their anatomical relationship. Methods and Results: Three patterns were designed, using potentials in the PA, right atrium (RA) and CS, to predict the side of AT. Two patterns were for left-sided AT and 1 pattern was for right-sided AT. Ten left-sided and 11 right-sided ATs were investigated regardless of mechanism. Electrode catheters were inserted in the RA, His bundle region, and CS, and an ablation catheter was inserted into the left and/or right PA. The sequences from these catheters were analyzed before detailed electroanatomical mapping. Patterns were obtained for 20 of 21 ATs. The mechanism was focal in 16 ATs and macroreentry in 5. The method predicted left-sided AT with a sensitivity of 78%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 84%, and an accuracy of 90%. Conclusions: The use of potentials in PA combined with conventional RA and CS electrograms is useful for distinguishing left-sided AT from right-sided AT, regardless of mechanism.
Circulation Journal 10/2012; · 3.77 Impact Factor
-
Kazuyoshi Suenari,
Yukiko Nakano,
Yukoh Hirai,
Hiroshi Ogi,
Noboru Oda,
Yuko Makita, Shigeyuki Ueda,
Kenta Kajihara,
Takehito Tokuyama,
Chikaaki Motoda,
Mai Fujiwara,
Kazuaki Chayama,
Yasuki Kihara
[show abstract]
[hide abstract]
ABSTRACT: A detailed understanding of the left atrial (LA) anatomy in patients with atrial fibrillation (AF) would improve the safety and efficacy of the radiofrequency catheter ablation. The objective of this study was to examine the myocardial thickness under the lines of the circumferential pulmonary vein isolation (CPVI) using 64-slice multidetector computed tomography (MDCT). Fifty-four consecutive symptomatic drug-refractory paroxysmal AF patients (45 men, age 61 ± 12 years) who underwent a primary CPVI guided by a three-dimensional electroanatomic mapping system (Carto XP; Biosense-Webster, Diamond Bar, CA, USA) with CT integration (Cartomerge; Biosense-Webster) were enrolled. Using MDCT, we examined the myocardial thickness of the LA and pulmonary vein (PV) regions in all patients. An analysis of the measurements by the MDCT revealed that the LA wall was thickest in the left lateral ridge (LLR; 4.42 ± 1.28 mm) and thinnest in the left inferior pulmonary vein wall (1.68 ± 0.27 mm). On the other hand, the thickness of the posterior wall in the cases with contact between the esophagus and left PV antrum was 1.79 ± 0.22 mm (n = 30). After the primary CPVI, the freedom from AF without any drugs during a 1-year follow-up period was 78 % (n = 42). According to the multivariate analysis, the thickness of the LLR was an independent positive predictor of an AF recurrence (P = 0.041). The structure of the left atrium and PVs exhibited a variety of myocardial thicknesses in the different regions. Of those, only the measurement of the LLR thickness was associated with an AF recurrence.
Heart and Vessels 04/2012; · 2.05 Impact Factor
-
Hiroshi Ogi,
Yukiko Nakano,
Shumpei Niida,
Keigo Dote,
Yukoh Hirai,
Kazuyosi Suenari,
Yukiji Tonouchi,
Noboru Oda,
Yuko Makita, Shigeyuki Ueda,
Kenta Kajihara,
Katsuhiko Imai,
Taijro Sueda,
Kazuaki Chayama,
Yasuki Kihara
[show abstract]
[hide abstract]
ABSTRACT: Matrix metalloproteinases (MMPs) play an important role in degradation of the extracellular matrix of injured tissue. MMP-9 expression increases in fibrillating atrial tissue; however, the mechanism for this increase has not been clarified.
Changes in the expression of vascular endothelial growth factor (VEGF), VEGF receptors, and hypoxia-induced transcription factor-1alpha (HIF-1alpha) in fibrillating atrial tissue were investigated. Atrial tissue samples were obtained from 13 patients with atrial fibrillation (AF) and 25 patients without a history of AF (regular sinus rhythm, RSR) undergoing cardiac operations. Western blot, real-time polymerase chain reaction, and immunofluorescence analyses of the expression of VEGF, VEGF receptors, and HIF-1alpha were performed. The VEGF mRNA and protein levels increased significantly in the AF group compared with the RSR group (P<0.05), and the expression of HIF-1alpha protein was also significantly higher in the AF group. VEGF receptor-1 mRNA, a high-affinity receptor for VEGF, but not VEGF receptor-2 mRNA, was upregulated in the atria of the AF group (P<0.05). Immunofluorescence staining revealed excess production and co-localization of HIF-1alpha, VEGF and MMP-9 in the endothelium of the atrial arteries in the AF group.
It is possible that upregulation of HIF-1/VEGF is involved in the enhancement of MMP-9 expression under hypoxic conditions.
Circulation Journal 09/2010; 74(9):1815-21. · 3.77 Impact Factor
-
Yukiko Nakano,
Wataru Shimizu,
Hiroshi Ogi,
Kazuyoshi Suenari,
Noboru Oda,
Yuko Makita,
Kenta Kajihara,
Yukoh Hirai,
Akinori Sairaku,
Takehito Tokuyama,
Yukiji Tonouchi, Shigeyuki Ueda,
Taijiro Sueda,
Kazuaki Chayama,
Yasuki Kihara
[show abstract]
[hide abstract]
ABSTRACT: Risk stratification for Brugada syndrome remains controversial. We investigated the relationships between episodes of ventricular fibrillation (VF) and various clinical, electrocardiographic, electrophysiologic, and genetic parameters both retrospectively and prospectively.
Fifty-two patients with Brugada syndrome (49 men, average age 42 +/- 3 years) were studied. In the Brugada patients with a VF history, the frequency of a spontaneous Type 1 electrocardiogram (ECG) pattern in lead V2 was significantly higher and the STJ amplitude in the V1 and V2 leads was also higher than in those without a VF history. Multivariate analyses revealed that the spontaneous Type 1 ECG pattern in lead V2 (but not lead V1) was the only independent predictor of a VF history. During a mean follow-up period of 39 +/- 4 months, 38.8% of the patients with a VF history and 2.9% of those without experienced an appropriate implantable cardioverter-defibrillation owing to VF. A multivariate analysis using a Cox's proportional hazard model showed that a VF history and spontaneous Type 1 ECG pattern in lead V2 were independent predictors of subsequent VF events.
A spontaneous Type 1 Brugada ECG pattern in lead V2 (but not lead V1) was both a prospective and retrospective independent predictor of VF episodes in Brugada syndrome.
Europace 03/2010; 12(3):410-6. · 1.98 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A 74-year-old female with a diagnosis of idiopathic dilated cardiomyopathy and ventricular tachycardia died suddenly 9 years after an implantation of an implantable cardioverter-defibrillator (ICD). The destructive removal of an ICD generator and the leads by an uninformed coroner resulted in the loss of the fragile electrograms during the terminal episodes of VT/VF and caused severe charring on the surface of the ICD generator. In order to observe the conditions in which the shock deliveries occurred during the noise detection, we programmed the ICD to deliver the maximum shock energy via a programmer while keeping continuous contact between the device surface and shock lead. The maximum shock energy of 31 Joules produced significant sparks from the surface of the ICD. To avoid the loss of data from an ICD and injury to the patient, widespread notification and education through appropriate scientific societies about the functions of ICDs are highly recommended.
International Heart Journal 11/2009; 50(6):823-7. · 1.16 Impact Factor
