Biomedical subjects

Goro Shinbo

Publications and source records attributed to Goro Shinbo.

7 recordsLinked to original sources

PubMed2006

Significance and utility of plasma brain natriuretic peptide concentrations in patients with idiopathic ventricular arrhythmias.

BACKGROUND: Secretion of B-type natriuretic peptide (BNP) appears to be regulated mainly by wall tension, and an increase in the plasma BNP concentration is considered to reflect ventricular structural and functional abnormalities. The aim of this study was to clarify the significance and utility of the measurement of the plasma BNP in the setting of idiopathic ventricular arrhythmias (I-VT/PVCs). METHODS: This study included 135 patients with symptomatic, monomorphic I-VT/PVCs (73 women; 53 +/- 17 years; 50 ventricular tachycardias [VTs], 85 premature ventricular contractions) who underwent radiofrequency catheter ablation. None had structural heart disease or renal dysfunction. RESULTS: The plasma BNP concentration exceeded the normal range (>18.4 pg/mL; high BNP concentration) in 79 patients (56%). The high BNP concentration was found more often in I-VT/PVCs originating from the left ventricle (LV; 74%) than the right ventricle (RV; 49%; P < 0.01). The plasma BNP concentration correlated with the age (P = 0.0001) and frequency of premature ventricular contractions (P < 0.0001), and left-sided I-VT/PVCs and the presence of controlled hypertension were independent predictors of a high BNP concentration (both P < 0.05). In patients with a successful ablation and high BNP concentration before the ablation, the BNP concentration decreased to the normal range in 61% of patients after ablation. In patients with a failed ablation, the BNP concentration did not decrease to the normal range after ablation in any of the patients (P < 0.0005). CONCLUSIONS: The plasma BNP concentration was elevated in about 60% of the patients with symptomatic I-VT/PVCs. Normalization of the high BNP concentration after ablation may indicate a successful ablation.

Adolescent↗

PubMed2005

Simultaneous mapping in the left sinus of valsalva and coronary venous system predicts successful catheter ablation from the left sinus of valsalva.

Idiopathic ventricular tachycardia originating from the left epicardium (Epi-VT) can be ablated from the left sinus of Valsalva (LSV) in selected patients. We hypothesized that the analysis of electrograms at the LSV and transitional zone from the great cardiac vein to the anterior interventricular vein (GCV-AIV) could predict the efficacy of radiofrequency catheter ablation (RFCA) from the LSV. Simultaneous mapping in the LSV and coronary venous system was performed in 25 patients (12 VTs and 13 premature ventricular contractions). The earliest ventricular activation (VA) during the arrhythmias was found at the LSV or GCV-AIV in all patients. RF applications from the LSV were successful in 17 patients success group (S-Gr) and failed in 8 failure group (F-Gr). The earliness of the VA recorded in the LSV (VA[LSV]) and in GCV-AIV (VA[GCV-AIV]) was compared between the two groups. (1) The VA[LSV] preceded the QRS onset by 28 +/- 11 ms in S-Gr and 14 +/- 10 ms in F-Gr (P < 0.01). (2) In S-Gr, the VA[GCV-AIV] was earlier than the VA[LSV] in 5 five patients (35%). However, in F-Gr, the VA[GCV-AIV] was earlier than the VA[LSV] in all patients. (3) In patients in whom the earliest VA was found at the LSV or GCV-AIV, a VA [GCV-AIV] preceding the VA[LSV] by less than 10 ms identified successful RFCA from the LSV with a sensitivity of 88 %, specificity of 100%, and high predictive value. With a detailed analysis of the electrograms recorded from the GCV-AIV and LSV, it was possible to identify the successful catheter ablation of Epi-VT from the LSV.

Catheter Ablation↗

PubMed2005

Three-dimensional visualization of the coronary venous system using multidetector row computed tomography.

BACKGROUND: This study was undertaken to investigate the applicability and image quality of contrast-enhanced visualization of the coronary venous system (CVS) by multidetector row computed tomography (MDCT). METHODS AND RESULTS: A total of 70 patients underwent MDCT and for each patient, 6 data sets were created throughout the cardiac cycle. The number and location of coronary veins were evaluated in 3-dimensional images using the 6 data sets. The quality of all images reconstructed from the 6 data sets was too poor to evaluate the CVS in 6 patients (9%). In the remaining 64 patients (91%), the diameter of the CVS was usually greater in the images reconstructed from data acquired during systole than in those reconstructed from data acquired during diastole. However, artifacts were observed more often in images from systole than from diastole. The coronary sinus and middle cardiac vein were visible in all 64 patients. The left marginal and posterior veins also were identified in 54 (84%) and 60 patients (94%), respectively. CONCLUSIONS: MDCT can be used as a non-invasive modality for evaluating the CVS anatomy in most patients.

Adult↗

PubMed2004

Significance of two potentials for predicting successful catheter ablation from the left sinus of Valsalva for left ventricular epicardial tachycardia.

The aim of this study was to identify the characteristics of electrograms that may be helpful in predicting successful ablation of idiopathic ventricular tachycardia from the aortic sinus of Valsalva. Data were obtained from 23 patients with symptomatic ventricular tachycardia or premature ventricular contractions (LV-VT) who underwent RF catheter ablation from the left sinus of Valsalva. Electrograms before and after application of RF energy during sinus rhythm and during LV-VT were analyzed. Complete elimination of LV-VT was finally achieved in 21 (91%) patients. The incidence of presystolic potentials preceding the QRS complex of LV-VT (P1 potential) was 90% for the 21 successful ablation sites, which did not differ from the incidence for the 24 unsuccessful sites (79%; P = 0.5). During sinus rhythm, a potential following the QRS complex (P2 potential) was more often recorded at the successful ablation site than at an unsuccessful ablation site before and after application of RF energy (before, P < 0.05; after, P < 0.001). The appearance of the P2 potential or a delay in the preexisting P2 potential after application of RF energy was observed only at the successful ablation sites (P < 0.001). In 18 control individuals who had no LV-VT, no P2 potential was recorded within the left sinus of Valsalva. Although the P1 potential may be useful for identifying the successful ablation site, its sensitivity is low. The appearance of the P2 potential or an increasingly delayed P2 potential after application of RF energy may be more useful than the P1 potential for predicting successful ablation.

Catheter Ablation↗

PubMed2004

Prevalence and characteristics of idiopathic outflow tract tachycardia with QRS alteration following catheter ablation requiring additional radiofrequency ablation at a different point in the outflow tract.

Subtle variations in QRS morphology occurs during idiopathic outflow tract ventricular tachycardia (OTVT), but no studies have clarified the prevalence and characteristics of the OTVT with altered QRS morphology following radiofrequency catheter ablation (RFA), which then require an additional RF application at a different portion of the outflow tract to abolish OTVT. Of 202 patients with a monomorphic VT or premature ventricular contraction (PVC) originating from the outflow tract, 6 (3%) showed changes in QRS morphology in the OTVT following RFA, requiring an additional RF application to the outflow tract at a different portion. In all six patients, RFA was applied for the first or second OTVT to a right or left ventricular endocardial site, with the other site being the left sinus of Valsalva. In each patient, OTVT before or after the changes in QRS morphology had characteristic ECG findings originating from a particular portion of the outflow tract. Changes in QRS morphology consistently included an increase or decrease in R wave amplitude in all inferior leads. Detailed continuous observation of QRS morphology in OTVT, especially R wave amplitude in inferior leads, is important for identifying changes of QRS morphology during catheter ablation. Mapping and ablation at a different portion of the outflow tract is then needed for cure.

Adult↗

PubMed2004

Prevalence and electrocardiographic characteristics of idiopathic ventricular arrhythmia originating in the free wall of the right ventricular outflow tract.

BACKGROUND: The prevalence and ECG characteristics of idiopathic ventricular arrhythmia originating in the free wall of the right ventricular outflow tract (RVOT) require further clarification, which was the aim of the present study of 110 patients with idiopathic ventricular tachycardia (n=34) or premature ventricular contraction (n=76; OT-VT/PVC) who underwent successful catheter ablation at the RVOT. METHODS AND RESULTS: Ten OT-VT/PVCs (9%) were ablated successfully at the free wall (FW-VT/PVC); the remaining 100 (91%) were ablated at the RVOT septum (Sep-VT/PVC). R wave amplitudes in the inferior leads were significantly smaller in FW-VT/PVC than in Sep-VT/PVC (p<0.01). An RR' pattern in the inferior leads was observed significantly more often in FW-VT/PVC than in Sep-VT/PVC (p<0.001). QS-wave amplitude in each of leads V(1) to V(3) was significantly deeper in FW-VT/PVC than in Sep-VT/PVC (p<0.001). ECG criteria requiring an RR' pattern in all inferior leads as well as an S-wave amplitude of at least 3.0 mV in lead V(2) differentiated FW-VT/PVC from Sep-VT/PVC with high sensitivity, specificity, and predictive accuracy. CONCLUSIONS: Although FW-VT/PVC has a relatively low prevalence, it has several distinctive ECG characteristics and detailed ECG analysis can differentiate it from Sep-VT/PVC.

Adult↗

PubMed2003

Segmental pulmonary vein isolation for paroxysmal atrial fibrillation improves quality of life and clinical outcomes.

The purpose of this study was to clarify the change in the quality of life (QOL) and clinical outcomes following segmental pulmonary vein (PV) isolation for paroxysmal atrial fibrillation (AF) in 50 patients with drug-refractory, paroxysmal AF. The left superior, left inferior, and right superior PVs were targeted for isolation in all patients, and the right inferior PV was isolated in 4 patients. AF recurred in 22 of 50 patients, and these patients were treated with class I or class III antiarrhythmic drugs that had been ineffective before the ablation procedure. The symptom severity and frequency was scored and the QOL was assessed using the Short-Form-36 questionnaire (SF-36) before the PV isolation and at the end of the follow-up period (6.0+/-3.0 months). PV isolation resulted in a reduction in the symptom severity (p<0.001) and symptom frequency (p<0.001) scores as compared with the pre-ablation values. Ninety percent of the patients had a >90% reduction in the frequency of symptomatic episodes of AF after the ablation procedure. The mean SF-36 physical and mental component summary scores also significantly improved after PV isolation as compared with the pre-ablation values (both for p<0.001). With a segmental isolation approach that targets at least 3 PVs, satisfactory improvement in the symptoms and QOL can be achieved in patients with drug-refractory, paroxysmal AF.

Aged↗