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Biomedical subjects

Koichi Taniguchi

Publications and source records attributed to Koichi Taniguchi.

At least 19 recordsLinked to original sources

Atrial tachycardia arising from the right atrial inferoseptum masquerading as common atrial flutter.

Radiofrequency catheter ablation was performed in 2 patients with atrial tachycardia (AT). In both cases the AT originated from the inferoseptal portion of the right atrium, and the cycle length was 210 ms. The surface ECG demonstrated common counterclockwise atrial flutter, probably caused by functional block in the clockwise direction at the cavo-tricuspid isthmus and posterior right atrium with rapid activation of the origin. Although rare (2%), AT originating from the inferoseptum of the right atrium should be considered when the surface ECG exhibits common atrial flutter.

Adult↗

Idiopathic ventricular arrhythmias originating from the tricuspid annulus: Prevalence, electrocardiographic characteristics, and results of radiofrequency catheter ablation.

BACKGROUND: Idiopathic ventricular tachycardias (VTs) and premature ventricular contractions (PVCs) arising from the tricuspid annulus have been reported. OBJECTIVE: The purpose of this study was to clarify the prevalence and characteristics of VT/PVCs originating from the tricuspid annulus. METHODS: The ECG characteristics and results of radiofrequency (RF) catheter ablation were analyzed in 454 patients with idiopathic VT/PVCs. RESULTS: Thirty-eight (8%) patients had VT/PVCs arising from the tricuspid annulus: 28 VT/PVCs (74%) originated from the septal portion of the tricuspid annulus and the remaining 10 (26%) from the free wall of the tricuspid annulus. QRS duration and Q-wave amplitude in each of leads V1-V3 were greater in VT/PVCs arising from the free wall of the tricuspid annulus than those from the septum of the tricuspid annulus (all P < .01). "Notching" of the QRS complex was observed more often in VT/PVCs arising from the free wall of the tricuspid annulus than those from the septum of the tricuspid annulus (P < .01). A Q wave in lead V1 was observed more often in VT/PVCs arising from the septum of the tricuspid annulus than those from the free wall of the tricuspid annulus (P < .005). R-wave transition occurred beyond lead V3 more often in VT/PVCs arising from the free wall of the tricuspid annulus than those from the septum of the tricuspid annulus (P < .005). RF catheter ablation eliminated 90% of the VT/PVCs arising from the free wall of the tricuspid annulus but only 57% of the VT/PVCs arising from septum of the tricuspid annulus. CONCLUSION: Idiopathic VT/PVCs arising from tricuspid annulus are not rare, and the detailed origin can be determined by ECG analysis. The preferential site of origin was the septum but also could be the free wall of the tricuspid annulus.

Cardiac Catheterization↗

Association of Gln222Arg polymorphism in the deoxyribonuclease I (DNase I) gene with myocardial infarction in Japanese patients.

AIMS: We have recently reported that serum deoxyribonuclease I (DNase I) activity, which may be involved in apoptosis, increases abruptly in the early phase of acute myocardial infarction (MI) [Kawai Y, Yoshida M, Arakawa K, Kumamoto T, Morikawa N, Masamura K, Tada H, Ito S, Hoshizaki H, Oshima S, Taniguchi K, Terasawa H, Miyamori I, Kishi K, Yasuda T. Diagnostic use of serum deoxyribonuclease I activity as a novel early-phase marker in acute myocardial infarction. Circulation 2004;109:2398-2400]. Death of vascular smooth muscle cells, in part because of apoptosis, is postulated to heighten susceptibility to disruption of vulnerable plaque, resulting in onset of MI. The present study evaluated the possibility that Gln222Arg polymorphism of the DNase I gene may be one of the factors involved in predisposition to MI. METHODS AND RESULTS: We assessed 611 Japanese patients: 311 with MI and 300 with stable angina pectoris (AP). Three common phenotypes determined by two common codominant alleles, DNASE1*1 and *2, whose corresponding gene products exhibit different properties, were found in these patient groups. The prevalence of DNASE1*2 was significantly higher in patients with MI than in those with AP (0.543 vs. 0.428, P < 0.001), being confirmed by phenotyping of the second study population. Multiple logistic regression analysis showed that the odds ratio of DNASE1*2 was 1.51 [95% confidence interval (CI) 1.04-2.18]. The association of the DNASE1*2 allele with MI was statistically significant, being independent of other conventional risk factors. CONCLUSION: Our data demonstrate that Gln222Arg polymorphism in the DNase I gene is associated with MI in the Japanese patients.

Aged↗

Nicorandil administration shows cardioprotective effects in patients with poor TIMI and collateral flow as well as good flow after AMI.

BACKGROUND: Nicorandil (NCR) has been reported to have cardioprotective effects in patients with AMI. And collateral flow and TIMI flow are also important determinants of final salvaged myocardium in patients with AMI. There is no evidence as to whether TIMI or collateral flow modifies the cardioprotective effects of NCR in patients with AMI. METHODS AND RESULTS: We studied 68 initial AMI patients without restenosis which was defined as 50% diameter reduction of the intervention site in the chronic period. On initial CAG, 41 patients with poor flow (collateral: Rentrop 0 or 1 and TIMI 0 or 1) were NCR/Non-NCR = 20/21. Twenty-seven patients with good flow (collateral: Rentrop 2 or 3 or TIMI 2 or 3) were NCR/Non-NCR = 13/14. NCR was administered intravenously (4 mg) via intracoronary injection (2 mg) or continuously (4 mg/h). 99mTc-tetrofosmin (TF) and 123I-BMIPP SPECT were performed in the subacute and chronic (6 Mo) periods. In 20 SPECT segments, summed defect scores (TDS) and regional wall motion (WMS: -1=dyskinesis -4 = normal) of AMI segments using TF-QGS were estimated. In poor flow patients, the following values for NCR patients were higher (p < 0.05) than for Non-NCR patients in the improvement degree of TDS (BMIPP) (NCR: 6.5 +/- 3.9 vs. Non-NCR: 4.0 +/- 3.4), the improvement degree of TDS (TF) (NCR: 5.7 +/- 4.6 vs. Non-NCR: 2.2 +/- 4.6), and delta WMS (NCR: 1.4 +/- 1.1 vs. Non-NCR: 0.9 +/- 1.0). In good flow patients, the following values for NCR patients were better (p < 0.05) than for Non-NCR patients in TDS (BMIPP) (subacute) (NCR: 9.9 +/- 5.2 vs. Non-NCR: 16.5 +/- 10.4) and (chronic) (NCR: 5.1 +/- 5.2 vs. Non-NCR: 12.4 +/- 8.5), WMS (subacute) (NCR: 1.7 +/- 1.3 vs. Non-NCR: 1.0 +/- 1.0), and WMS (chronic) (NCR: 3.0 +/- 1.5 vs. Non-NCR: 2.1 +/- 1.3). CONCLUSION: We conclude that the cardioprotective effects of nicorandil administration are observable in both AMI patients with poor collateral and TIMI flow and good flow before reperfusion therapy.

Blood Flow Velocity↗

Radiofrequency catheter ablation within the coronary sinus eliminates a macro-reentrant atrial tachycardia: importance of mapping in the coronary sinus.

We describe a patient who underwent radiofrequency (RF) catheter ablation of symptomatic atrial fibrillation. After left atrial (LA) catheter ablation and pulmonary vein isolation, a macro-reentrant atrial tachycardia (AT) with a critical isthmus at the mitral isthmus was induced by incremental atrial pacing from the coronary sinus. Extensive RF energy applications from endocardial sites using ablation catheters with 4 mm- and 8 mm- tips resulted in no discrete potentials being recorded from the endocardial sites of the isthmus, but the tachycardia could not be terminated. However, discrete potentials were recorded within the CS, and epicardial RF energy applications from the CS eliminated the tachycardia. Thus, mapping in the CS is useful for detecting residual conduction at epicardial sites along the mitral isthmus. RF catheter ablation within the CS should be considered when no distinct electrograms are recorded after extensive ablation from the endocardial sites and when distinct electrograms are recorded within the CS.

Atrial Fibrillation↗

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↗

Prognostic impact of ventilatory efficiency in heart disease patients with preserved exercise tolerance.

BACKGROUND: The minute ventilation/carbon-dioxide output (VE/VCO2) slope as a marker of cardiac events has been established in patients with severe heart failure, but it is not known whether it is useful for other heart diseases. METHODS AND RESULTS: The present study investigated 215 patients with various heart diseases (age 59+/-11 years; ischemic heart disease, n=89; dilated cardiomyopathy, n=38; valvular disease, n=37; hypertensive heart disease, n=33; others, n=18) who underwent cardiopulmonary exercise testing to determine the VE/VCO(2) slope. Patients were divided into 2 groups according to the VE/VCO2 slope and were followed-up for 3 years. Forty-eight cardiac events (6 deaths, 42 re-hospitalizations) occurred during the observation period. Patients with a VE/VCO2 slope >34 had a significantly higher 3-year cardiac event rate (32.1%) than patients with VE/VCO2 slope <34 (18.9%, p<0.05). When patients were selected with relatively preserved peak oxygen uptake values (>16 ml . kg (-1) . min(-1)), patients with VE/VCO2 slope >34 still demonstrated a significantly higher cardiac event rate than other patients (35.0% vs 13.3%, p<0.01). CONCLUSION: The VE/VCO2 slope may be a prognostic indicator of cardiac events in a heterogeneous group of patients with heart disease, independent of exercise tolerance.

Aged↗

Functional mitral regurgitation during exercise in patients with heart failure.

BACKGROUND: Functional mitral regurgitation (MR) is common in patients with chronic heart failure (CHF) and left ventricular dysfunction. The severity of CHF is expressed in terms of exercise tolerance, so MR during exercise would affect the severity of heart failure. However, it is not well known how much MR increases during exercise, or if it is related with severity of heart failure. METHODS AND RESULTS: Seventeen subjects underwent dynamic cycle exercise at steady-state levels of 80% and 150% of anaerobic threshold (AT). During each exercise level, the MR jet and left atrial (LA) area were measured, and the degree of MR was expressed as the ratio (MR/LA). The MR/LA increased slightly at 80% AT (rest: 15.5+/-7.8%, 80% AT: 21.7+/-9.3%, p<0.05). It increased more at 150% AT (29.2+/-11.6%, p<0.01). The MR/LA at both 80% and 150% AT weakly correlated with peak oxygen consumption/heart rate (r=-0.509). They showed a weakly positive correlation with the ventilatoly equivalent/CO(2) production slope (r=0.340). CONCLUSIONS: MR during exercise increases as stroke volume worsens during exercise, so evaluation of MR during exercise is important in the management of patients with CHF.

Aged↗

Serum deoxyribonuclease I activity can be used as a sensitive marker for detection of transient myocardial ischaemia induced by percutaneous coronary intervention.

AIMS: Cardiac markers such as troponin T (c-TnT) have proven unsuitable for the detection of early and transient myocardial ischaemia. We recently reported that abrupt elevation of serum deoxyribonuclease I (DNase I) activity in the early stage of acute myocardial infarction could be used as a diagnostic marker. To evaluate whether serum DNase I could be used as a marker of early myocardial ischaemia, we investigated alterations in its levels after transient ischaemia induced during percutaneous coronary intervention (PCI). METHODS AND RESULTS: In 24 consecutive patients with stable angina undergoing elective PCI and 12 patients undergoing coronary angiography (CAG), serum samples were tested for DNase I, creatine kinase isoenzyme MB (CK-MB), and c-TnT before, soon after, and 3 and 12-24 h after completion of the procedures. Serum DNase I activity had risen significantly from baseline by 3 h after PCI in 21 of the 24 PCI patients. The mean per cent difference from baseline in serum DNase I activity 3 h after PCI was 35.9+/-37.5%. Even among the 16 PCI patients whose levels of CK-MB and c-TnT were within the normal range, 13 showed elevation of serum DNase I activity from baseline after PCI. In the CAG patient group, DNase I activity levels remained unchanged at all times after CAG. CONCLUSION: Elevation of serum DNase I activity can be used as a sensitive marker for detection of transient myocardial ischaemia.

Aged↗

Idiopathic ventricular arrhythmia arising from the mitral annulus: a distinct subgroup of idiopathic ventricular arrhythmias.

OBJECTIVES: We sought to clarify the prevalence and characteristics of idiopathic ventricular tachycardia or premature ventricular contraction originating from the mitral annulus (MAVT/PVC). BACKGROUND: Recent case reports have presented patients with MAVT/PVC. METHODS: Electrocardiographic (ECG) characteristics and the results of electrophysiologic investigation and radiofrequency catheter ablation (RFCA) were analyzed in 352 patients with symptomatic idiopathic ventricular tachycardia (IVT)/premature ventricular contraction (PVC). RESULTS: Nineteen cases of IVT/PVC (5%) represented MAVT/PVC. Of these, 11 (58%) originated from the anterolateral portion of the mitral annulus (AL-MAVT/PVC), and 2 (11%) arose from the posterior portion (Pos-MAVT/PVC). The remaining six cases of MAVT/PVC (31%) had posteroseptal origin (PS-MAVT/PVC). In all patients, an S-wave was present in lead V(6). The QRS polarity in inferior leads and leads I and aVL was useful for differentiating AL-MAVT/PVC from Pos-MAVT/PVC or PS-MAVT/PVC. The Pos-MAVT/PVC had an Rs pattern in lead I and an R pattern in lead V(1), whereas PS-MAVT/PVC invariably had an R pattern in lead I and a negative QRS component in lead V(1). The AL-MAVT/PVC and Pos-MAVT/PVC showed a longer QRS duration than the PS-MAVT/PVC (p < 0.001), and all had late-phase "notching" of the QRS complex in inferior leads. In all patients, RFCA eliminated MAVT/PVC, with no recurrences during follow-up for 21 +/- 15 months. CONCLUSIONS: Mitral annular VT/PVC is a rare but distinct subgroup of IVT/PVC. MAVT/PVC origin could be determined by ECG analysis. The AL and PS sites of the MA were preferential.

Adult↗

Tissue tracking imaging as a new modality for identifying the origin of idiopathic ventricular arrhythmias.

Tissue tracking imaging was performed in 33 patients with idiopathic ventricular arrhythmias before radiofrequency catheter ablation. The site of the arrhythmia origin, defined as the site where the earliest color-coded signal appeared on the myocardium at the onset of the arrhythmia, corresponded to the site of origin as determined on fluoroscopy during activation mapping in all patients. Catheter ablation at that site abolished the arrhythmia in 29 patients (88%).

Catheter Ablation↗

Primary malignant peripheral nerve-sheath tumor of the common bile duct.

Primary malignant peripheral nerve-sheath tumors of the common bile duct are extremely rare. To our knowledge, the published literature contains no previous case report of this disease. Here we report on a 58-year-old Japanese woman with a primary malignant peripheral nerve-sheath tumor of the common bile duct, which was completely resected. A hypoechoic mass was identified in the hepatic hilus, using ultrasonography and computed tomography. Endoscopic retrograde cholangiography revealed a smooth stricture and deviation of the common bile duct. Laparotomy exposed a firm mass around the common bile duct that had not invaded the surrounding tissues. Partial resection of the common bile duct and cholecystectomy were performed as the treatment of choice. The final histopathological diagnosis was malignant peripheral nerve-sheath tumor arising from the wall of the common bile duct.

Cholangiopancreatography, Endoscopic Retrograde↗

Long-term results of cryoablation with a new cryoprobe to eliminate chronic atrial fibrillation associated with mitral valve disease.

The purpose of this study was to examine the performance of a new cryoprobe in the treatment of chronic atrial fibrillation (AF) associated with mitral valve disease. The study included 66 patients undergoing mitral valve replacement. The mean AF duration was 9.0 +/- 9.0 years and mean left atrial (LA) was diameter 57 +/- 10 mm. Cryoablation (-60 degrees C) was applied to four pulmonary vein (PV) orifices over 2-3 minute. The spherical tip (2-cm in diameter) of the cryoprobe is capable of ablating the left atrium near the PV, as well as the PV ostium with a single cryoablation. After cryoablation, mitral valve surgery or a combined surgical procedure were performed in 66 patients. There were no intraoperative complications. Sinus rhythm was restored in 60 patients (91%) immediately after the operation. Recurrent AF was treated with antiarrhythmic drugs and/or direct current cardioversion in 43 patients (72%). At discharge, 48 patients (72%) were in sinus rhythm. During a mean follow-up period of 31 +/- 16 months, 40 patients (61%) were in sinus rhythm with (29) or without antiarrhythmic drugs (11). In patients in sinus rhythm at the end of the follow-up period, the duration of preoperative AF duration was significantly shorter (P < 0.05) and the preoperative LA diameter and cardiothoracic ratio were significantly smaller than in patients who were in AF (both for P < 0.005). Using this new cryoprobe, sinus rhythm was restored and maintained in 61% of patients with chronic AF and mitral valve disease with a 12-15 minute cryoablation procedure.

Atrial Fibrillation↗

Biatrial epicardial pacing prevents atrial fibrillation and confers hemodynamic benefits after coronary artery bypass surgery.

Biatrial pacing (BIP) can be more effective than standard right atrial pacing (RAP) in preventing atrial fibrillation (AF) after coronary artery bypass graft surgery (CABG). However, the mechanisms and hemodynamic benefits of BIP have not been studied in detail. This study examined the efficacy and hemodynamic benefits conferred by overdrive epicardial BIP in preventing post-CABG AF. After undergoing CABG, 72 patients (mean age = 66 +/- 12 years, 48 men) were randomly assigned to triggered BIP (BIP-AAT; n = 50) versus single RAP (RAP-AAI; n = 22). The hemodynamic effects of BIP were measured by right heart catheterization and echocardiography. The patients were monitored for 8.8 +/- 2.4 days after CABG to detect episodes of AF. The incidence of AF was significantly lower in the BIP-AAT group (22.0%) than in the RAP-AAI group (59.1%, P < 0.01). Cardiac output was significantly higher and pulmonary artery wedge pressure (PAWP) significantly lower during BIP-AAT than during RAP-AAI. The E-wave (65.2 +/- 37.8 vs 57.8 +/- 37.8 cm/s, P < 0.05) was significantly higher during BIP-AAT, and the interval between atrial pacing spike and the end of A-wave (241 +/- 18.4 vs 286 +/- 17.2 ms, P < 0.001) was significantly shorter during BIP-AAT than during RAP-AAI. Triggered BIP was well tolerated and significantly reduced the incidence of post-CABG AF compared to single-site RAP. The hemodynamic improvements conferred by BIP-AAT were due to a shortening of the inter-atrial conduction delay and greater contribution of left atrial contraction. These hemodynamic benefits may play a role in lowering intra-atrial pressure and in preventing AF.

Aged↗

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↗

Pulmonary vein morphology before and after segmental isolation in patients with atrial fibrillation.

BACKGROUND: The morphology of the pulmonary veins (PVs) before and after segmental isolation of the PVs has not been sufficiently characterized. METHODS AND RESULTS: Multi-slice computed tomography was performed before and 3 +/- 1 months after ablation in 30 patients with atrial fibrillation who underwent PV isolation. Before ablation, PV narrowing (> or =25% luminal reduction) was found in nine (8%) PVs. After ablation, de novo PV narrowing was found in 24 PVs (26%) and was detected only in the supero-inferior direction in 14 PVs (58%). The diameter reduction inside the PVs after ablation was greater in the supero-inferior direction (14 +/- 12%) than in the antero-posterior direction (9 +/- 13%; P < 0.0001). In the ablated PVs, the PV trunk was shorter than before ablation (P < 0.0001). The reduction in the diameters of both the PV ostium and the ablation site in the ablated PVs, as well as the diameter of the PV ostium in the nonablated PVs, correlated with the decrease in the left atrial diameter. Shortening of the PV trunk correlated with the severity of PV narrowing, but it was not related to the percent diameter reduction of the left atrium. PV narrowing before or after ablation did not result in any clinical consequences. CONCLUSIONS: PV narrowing is present in about 10% of PVs before ablation. Asymmetric luminal reduction and longitudinal shrinkage of the PV trunk occur after ablation. Reverse remodeling of the PV and contraction of the PV wall may contribute to the reduction in the PV diameter. PV morphology should be assessed with multi-directional views to avoid missing heterogeneous legions.

Analysis of Variance↗