Complete free wall isolation of arrhythmogenic persistent left superior vena cava

INTRODUCTION

Persistent left superior vena cava (PLSVC) is one of the major sources of triggers and drivers of atrial fibrillation (AF). There has been no established PLSVC ablation procedure to eliminate the arrhythmogenicity along the entire length of PLSVC.

METHODS AND RESULTS

A 70-year-old woman with a history of two previous catheter ablations for AF, mitral valvuloplasty, and an unroofed coronary sinus-type atrial septal defect closure underwent the redo AF ablations. The AF trigger and driver were identified within the patient's enlarged PLSVC. The AF was treated by complete PLSVC free wall isolation.

CONCLUSION

Complete PLSVC free wall isolation may be an effective ablation method to eliminate the arrhythmogenicity along the entire length of the PLSVC.

Systematic observation-based diagnosis of atrioventricular nodal reentrant tachycardia with a bystander concealed nodoventricular pathway

Background

This study aimed to establish a systematic method for diagnosing atrioventricular nodal reentrant tachycardia (AVNRT) with a bystander concealed nodoventricular pathway (cNVP).

Methods

We analyzed 13 cases of AVNRT with a bystander cNVP, 11 connected to the slow pathway (cNVP-SP) and two to the fast pathway (cNVP-FP), along with two cases of cNVP-related orthodromic reciprocating tachycardia (ORT).

Results

The diagnostic process was summarized in three steps. Step 1 was identification of the presence of an accessory pathway by resetting the tachycardia with delay (n = 9) and termination without atrial capture (n = 4) immediately after delivery of a His-refractory premature ventricular contraction (PVC). Step 2 was exclusion of ORT by atrio-His block during the tachycardia (n = 4), disappearance of the reset phenomenon after the early PVC (n = 7), or dissociation of His from the tachycardia during ventricular overdrive pacing (n = 1). Moreover, tachycardia reset/termination without the atrial capture (n = 2/2) 1 cycle after the His-refractory PVC was specifically diagnostic. Exceptionally, the disappearance of the reset phenomenon was also observed in the two cNVP-ORTs. Step 3 was verification of the AVN as the cNVP insertion site, evidenced by an atrial reset/block preceding the His reset/block in fast-slow AVNRT with a cNVP-SP and slow-fast AVNRT with a cNVP-FP or His reset preceding the atrial reset in slow-fast AVNRT with a cNVP-SP.

Conclusion

AVNRT with a bystander cNVP can be diagnosed in the three steps with few exceptions. Notably, tachycardia reset/termination without atrial capture one cycle after delivery of a His-refractory PVC is specifically diagnostic.

Quantitative analysis of fractionated electrogram area of left atrium during right atrial pacing as an indicator of left atrial electrical remodeling in patients with atrial fibrillation

Background

The clinical significance of left atrial local electrogram fractionation after restoration of sinus rhythm in patients with atrial fibrillation (AF) has not been elucidated.

Methods

We evaluated ultrahigh-resolution maps of the left atrium (LA) during RA pacing acquired after pulmonary vein isolation in 40 patients with AF. The association between low-voltage area (LVA, <0.5 mV), fractionated electrogram area (FEA, the highlighted area with LUMIPOINT™ Complex Activation), the interval from onset of LA activation to wavefront collision at the mitral isthmus (LA activation time), and wave propagation velocity (WPV) was evaluated quantitatively.

Results

The total LVA, total FEA with ≥5.0 peaks or ≥7.0 peaks were 7.0 ± 7.9 cm2, 15.9 ± 12.9 cm2, and 5.2 ± 7.5 cm2, respectively. These areas were predominantly observed in the anteroseptal region. Total LVA, total FEA with ≥5.0 peaks, and total FEA with ≥5.0 peaks in the normal voltage area (NVA: ≥0.5 mV) correlated with LA activation time (R = 0.69, 0.75, and 0.71; each p < .0001). In the anterior wall, these areas correlated with regional mean WPV (R = -0.75, -0.83, and - 0.55; each p < .0001) and the extent of slow conduction area (SCA) with WPV <0.3 m/s (R = 0.89, 0.84, 0.33; p < .0001 for LVA and FEA, p < .05 for FEA located in NVA). The anterior wall FEA with ≥7.0 peaks and that in the NVA showed a better correlation in predicting anterior wall SCA (R = 0.92 and 0.86, each p < .0001).

Conclusion

Quantitative analysis of FEA together with LVA may facilitate the assessment of LA electrical remodeling.

First Report of Electromagnetic Interference Between Percutaneous Ventricular Assist Device and Implantable Cardioverter-Defibrillator

Electromagnetic interference (EMI) between implantable left ventricular assist devices and cardiac implantable electronic devices has been observed. We demonstrated the first case of EMI between a percutaneous ventricular assist device and an implantable cardioverter-defibrillator, validated by an extra vivo simulation test. EMI might depend on the distance between devices. (Level of Difficulty: Advanced.).

Delineation of an intra-isthmus reentry circuit around the coronary sinus ostium using an ultrahigh-resolution mapping system

•Intra-isthmus reentry is a variant of cavotricuspid isthmus-dependent atrial flutter. •Intra-isthmus reentry circuit can involve the rotational activation around the coronary sinus ostium. •Ultrahigh-resolution mapping can help delineate the complete intra-isthmus reentry circuit.

Left atrial anterolateral linear ablation for biatrial tachycardia via Bachmann's bundle, interatrial septum, and left atrial anterior wall under mitral isthmus block

Biatrial tachycardia via Bachmann's bundle, interatrial septum, and left atrial anterior wall can be treated by left atrial anterolateral linear ablation without left atrial appendage isolation, even under mitral isthmus block.

Subclinical sinus node dysfunction in patients with atrial fibrillation-Insight from ultrahigh-resolution mapping of human sinoatrial exits

BACKGROUND

Even a short duration of paroxysmal episodes of atrial fibrillation (AF) is associated with sinus node (SN) remodeling and a reduced SN reserve or dysfunction. The number of earliest atrial activation sites (EASs) during sinus rhythm decreases according to the decrease in the SN reserve.

OBJECTIVE

We sought to evaluate the EASs during sinus rhythm using an ultrahigh-density mapping system.

METHODS

This study included 35 patients (supraventricular tachycardia [SVT]/paroxysmal atrial fibrillation [PAF]/persistent atrial fibrillation [PsAF] = 5/21/9) who underwent ultrahigh-resolution endocardial mapping of the SN area at rest and during β-stimulation. The number of EASs was determined by the Lumipoint™ algorithm.

RESULTS

The number of EASs was greatest in SVT patients both at rest (SVT/PAF/PsAF = 1.4 ± 0.8/1.0 ± 0/1.0 ± 0, p = .04) and during β-stimulation (SVT/PAF/PsAF = 2.6 ± 1.0/1.3 ± 0.6/1.0 ± 0, p < .01). The number significantly increased with β-stimulation as compared to baseline in the PAF patients (p = .02), but not in the PsAF patients. The brain natriuretic peptide (BNP) level was significantly higher in AF than SVT patients (SVT/PAF/PsAF = 12.3 [10.1-14.5]/25.7 [14.8-36.0]/73.4 [57.6-140] pg/ml, p < .01). In the PAF patients, the BNP level was significantly higher in those with unicentric EASs than multicentric EASs during β-stimulation (28.1 [19.1-46.5] vs. 13.1 [9.4-26.9] pg/ml, p = .03), and the optimal cutoff point for the BNP level predicting unicentric EASs was 21.8 pg/ml (sensitivity 82.6%; specificity 85.7%).

CONCLUSIONS

AF patients have a smaller number of EASs and poorer response to β-stimulation than non-AF patients. An elevated BNP level might predict subclinical SN dysfunction in patients with PAF.

Declines in serum uric acid level after catheter ablation of atrial fibrillation

BACKGROUND

Few studies have examined whether catheter ablation for AF patients improves biomarkers other than serum levels of brain natriuretic peptide (BNP) and renal function. This study was to explore whether catheter ablation for atrial fibrillation (AF) patients affects uric acid (UA), glucose and lipid metabolism.

METHODS AND RESULTS

A total of 206 patients (66.6 ± 10.4 years; 132 men) who underwent initial AF ablation without changes to oral medications were included. Baseline BNP and UA levels significantly decreased at 1 year after ablation (p < 0.05 each). Changes in UA level correlated significantly with pre-procedural UA level (r = 0.57). In multivariable logistic regression modeling, pre-procedural UA level, persistent AF, and hemoglobin A1c (p < 0.05 each) were independent predictors of post-procedural UA level decline. Significant improvements in both persistent and paroxysmal AF patients were identified, and the magnitude of post-procedural serum UA level decline after ablation (ΔUA) was significantly greater in patients with persistent AF (0.8 ± 1.0 mg/dl) than in those with paroxysmal AF (0.2 ± 0.8 mg/dl, p < 0.001). Of the 48 patients with high UA level before procedure, 28 patients showed improvement in UA level to normal range.

CONCLUSIONS

Catheter ablation for AF patients significantly improved serum UA levels without obvious influences of heart failure, renal function, or inflammation, suggesting that AF ablation may be effective for AF patients with hyperuricemia. Trial registration The study was approved by the Research Ethics Committee of University of Fukui (no. 20210132) and clinical trial registration (UMIN000044669).

Evaluation of cryoballoon pulmonary vein isolation lesions during the acute and chronic phases using a high-resolution mapping system

BACKGROUND

An acute cryothermal ablation lesion contains both reversible and irreversible elements. However, differences in lesions created with cryoballoon pulmonary vein isolation (PVI) between the acute and chronic phases have not been fully elucidated.

METHODS

We retrospectively analyzed 23 consecutive patients with atrial fibrillation who underwent cryoballoon PVI during the initial procedure followed by a second ablation procedure. In all patients, cryoballoon PVI lesions were evaluated with high-resolution voltage mapping just after PVI (acute phase) and during the second session (chronic phase). We compared the area and width of the non-isolated left atrial posterior wall (NI-LAPW) with voltage ≥ 0.5 mV during both sessions.

RESULTS

PVI was successfully achieved in all patients. Cryoballoon PVI lesions were re-evaluated at 11 [2-17] months post-procedure. During the chronic phase, NI-LAPW width became significantly larger at the level of the roof (change, 5.8 ± 5.5 mm; p < 0.001) and at the level of the carina (change, 3.3 ± 7.0 mm; p < 0.05), and NI-LAPW area became significantly larger (change, 1.5 ± 1.9 cm²; p < 0.001) compared with the acute phase. Eight patients without any PV reconnections also had larger NI-LAPW areas (change, 1.3 ± 1.2 cm²; p < 0.05) during the chronic phase. Conduction resumption confined to the right carina was observed in 1 (4.3%) patient who presented with circumferential PVI that included the carina during the first session.

CONCLUSION

Acute cryoballoon PVI lesions significantly regressed during the chronic phase. PV reconnections and the isolation area should be carefully re-evaluated during the second procedure.

The feasibility and safety of substrate modification on the left atrial roof area using a cryoballoon in atrial fibrillation ablation

BACKGROUND

Data on additional substrate modification using a cryoballoon beyond cryoballoon pulmonary vein isolation (CB-PVI) is limited. We sought to evaluate the efficacy and safety of substrate modification on the left atrial roof area using CBs (LAR-CBs) for atrial fibrillation (AF) patients.

METHODS

Eighty-one AF patients (70.0[62.5-77.0] years, 33 paroxysmal AF[PAF], 48 non-PAF) underwent LAR-CBs following CB-PVIs. Voltage maps were created with a high-resolution mapping system. Roof line conduction block was evaluated during the repeat procedure.

RESULTS

The total number of applications for the CB-PVI and LAR-CB were 5.0 ± 1.2 and 3.8 ± 0.7, and both were significantly greater in non-PAF than PAF patients. LA roof areas had continuous scar in 61/79(77.2%) patients, and the mean balloon temperature was significantly lower in patients with continuous scar than those without (-39.3 ± 3.8 vs. 36.0 ± 4.6 °C, p = 0.004). The single procedure 1-year AF freedom was 87.6% (7.5% on antiarrhythmic drug) and was similar between PAF and non-PAF patients (p = 0.14). Twelve (14.8%) patients underwent a second procedure 5.5(2.2-7.5) months later, and a mean of 1.3 ± 0.5 PVs were reconnected in 7/12(58.3%) patients. Electrical conduction block across the roof line was proven in 3/12(25.0%) patients. There were 6(7.4%) complications related to the procedures, including iatrogenic roof dependent atrial tachycardia, takotsubo cardiomyopathy, and severe pericarditis in 1, 1, and 2 patients, respectively.

CONCLUSIONS

LA roof area substrate modification using CBs yielded a high arrhythmia freedom after single procedures. However, a low incidence of electrical conduction block across the line during the chronic phase and delayed complications were the major concerns.

Safety and durability of cavo-tricuspid isthmus linear ablation in the current era: Single-center 9-year experience from 1078 procedures

BACKGROUND

Cavo-tricuspid isthmus (CTI) linear ablation is performed not only for atrial flutter (AFL) but empirically during atrial fibrillation (AF) ablation in real-world practice.  PURPOSE: We sought to evaluate the safety and durability of the CTI ablation.  METHODS: This retrospective study included 1078 consecutive patients who underwent a CTI ablation. AFL was documented before or during the procedure in 249 (23.1%) patients, and an empirical CTI and AF ablation were performed in 829 (76.9%) patients.  RESULTS: CTI block was successfully created in 1051 (97.5%) patients with a 10.3 ± 6.6 min total radiofrequency time. Repeat procedures were performed for recurrent arrhythmias in 187 (17.3%) patients at a median of 11.0 (5.0-30.0) months postprocedure, and conduction resumption was identified in 68/174 (39.1%). Among those undergoing a CTI ablation with an AF ablation, the durability was significantly higher in those with than without documented AFL (78.1% vs. 58.2%, p = .031).  The total radiofrequency time was significantly shorter (9.0 ± 5.3 vs. 10.0 ± 6.4 [mins], p = .024) and durability significantly higher (78.1 vs. 58.7[%], p = .043) in the large-tip than irrigated-tip catheter group. Iatrogenic AFL was observed after the empiric CTI ablation in 11 (1.3%) patients. Procedure-related complications occurred in 15 (1.4%) patients. Eight patients experienced coronary artery spasms, including one with ventricular fibrillation following ST elevation on the ward. The other six patients experienced transient atrioventricular block and one experienced cardiac tamponade requiring drainage.  CONCLUSIONS: Despite a high acute CTI ablation success, the conduction block durability was relatively low after the empiric ablation. An empiric CTI ablation at the time of the AF ablation is not recommended.

High-Resolution Mapping and Ablation of Atrial Tachycardias Involving the Lateral Left Atrium

Background

The lateral left atrium (LA) is often associated with atrial tachycardia (AT) because of its complex anatomy. We sought to characterize ATs associated with the lateral LA, including the posterolateral mitral isthmus (MI) and left atrial ridge.

Methods and Results

Twenty‐eight lateral LA‐associated ATs were mapped with high‐resolution mapping systems and entrainment pacing. The vein of Marshall was mapped with a 1.8‐Fr mapping catheter when possible. ATs were associated with the posterolateral MI in 18 ATs (14 perimitral, 3 small reentry, and 1 focal AT). All patients had undergone MI area ablation, and all ATs were successfully eliminated. During 27.0 (interquartile range, 10.5–40.0) months of follow‐up, all were free from any atrial tachyarrhythmias, with 3 patients on antiarrhythmics. Of 10 ATs involving the ridge or Marshall bundle, 3 were ridge related, 3 were Marshall bundle related based on vein of Marshall mapping, and 1 was a persistent left superior vena cava related AT. All 7 patients had undergone MI linear ablation. The critical isthmus was in the LA‐ridge junction or the LA‐Marshall bundle junction. Bidirectional conduction block between the LA and ridge or Marshall bundle was created. Two patients had the critical isthmus in the other area. The remaining patient had micro‐reentry in the ridge. All 10 ATs were terminated during ablation at the critical isthmus. During 12.0 (5.2–31.7) months of follow‐up, all were free from any atrial tachyarrhythmias, with 7 patients on antiarrhythmics.

Conclusions

Most ATs occurred after MI area ablation. An high resolution mapping‐guided approach is highly effective for identifying the mechanism.

Premature ventricular contraction originating from the distal left anterior fascicle: The usefulness of a multipolar catheter with small electrodes in mapping presystolic Purkinje potential and pace mapping

Mapping and localizing presystolic Purkinje potentials are crucial for determining the optimal ablation site for fascicular premature ventricular contractions (PVCs). Here we present a case of PVCs originating from the distal left anterior fascicle (LAF). Activation mapping using a multipolar catheter with small electrodes demonstrated early presystolic Purkinje potentials during the PVCs. A moderately good pace-map match was also obtained near the successful ablation site. This case demonstrates the activation pattern of PVCs originating from the distal LAF and the usefulness of multipolar catheters with small electrodes for the mapping of fascicular PVCs.

Usefulness of electron microscopy in the diagnosis of wild-type transthyretin cardiac amyloidosis

Wild-type transthyretin cardiac amyloidosis (ATTRwt) has been recognized as an important cause of heart failure with preserved ejection fraction; thus, its accurate diagnosis is crucial. Herein, we describe the case of a 76-year-old man who presented with dyspnea and palpitation. On observing the laboratory evaluations and clinical course, we suspected cardiac amyloidosis. However, optical microscopic analysis by Congo-red and direct fast scarlet staining revealed no amyloid deposits in the biopsy samples. Therefore, a more thorough investigation was pursued by examining the myocardial tissue under electron microscopy. We could recognize amyloid deposits between the myocardial fibers using electron microscopy. We submitted all the pathological specimens to a specialized facility for genetic testing to ensure the accurate diagnosis of the amyloidosis disease type. As a result, a biopsy sample from the minor salivary gland was stained with the Congo red stain. Anti-transthyretin antibody detected using immunohistochemical analysis of amyloidosis supported the presence of transthyretin form of amyloid proteins. Genetic testing revealed the absence of TTR gene mutations. The final diagnosis was ATTRwt. We believe that this case suggests the usefulness of electron microscopy in the diagnosis of ATTRwt and other related disorders. Further study is warranted to validate our findings.

Ultrahigh resolution electroanatomical mapping of the transverse conduction of the right atrial posterior wall in cases with and without typical atrial flutter

INTRODUCTION

The right atrial posterior wall (RAPW) is known to form a conduction barrier during typical atrial flutter (AFL). We evaluated the transverse conduction properties of RAPW in patients with and without typical AFL using an ultrahigh resolution electroanatomical mapping system.

METHODS AND RESULTS

This study included 41 patients who underwent catheter ablation of AF, typical or atypical AFL, in whom we performed RAPW mapping with an ultrahigh resolution mapping system during typical AFL and coronary sinus ostial pacing with three different pacing cycle lengths (PCLs) (1) PCL1: PCL within 40 ms of the AFL cycle length in patients with typical AFL or 250-300 ms for those without, (2) PCL2: 400 ms, (3) PCL3: PCL just faster than the sinus rate. Local RAPW conduction block was evaluated by propagation mapping and local double potentials separated by an isoelectric line. The functional block was defined as areas blocked during shorter PCLs but conductive during longer PCLs. The degree of blockade was calculated by dividing the blocked length by RAPW length (%blockade). Only two patients demonstrated a fixed complete RAPW block (100%, %blockade). Thirty-one patients demonstrated a partial block of RAPW, and the %blockade during PCL1-3 was 49.4 ± 19.8%, 39.5 ± 19.2%, and 35.0 ± 22.9% in this group, respectively. Functional block areas were frequently observed above the fixed block area adjacent to the RA-inferior vena cava junction. Transverse conduction block was more frequently observed in patients with typical AFL at any longitudinal level of RAPW.

CONCLUSION

RAPW transverse conduction block is lower-side dominant and greater in patients with typical AFL than those without.

A cavotricuspid isthmus pouch revealed to be a breakout site for gap conduction of recurrent common atrial flutter

A cavotricuspid isthmus pouch can be a breakout site for gap conduction of cavotricuspid isthmus block line. If the previous block line is electrically silent, high-density 3-D mapping and pouchgraphy are useful to find the pouch and ablate within it.

A case of outflow tract premature ventricular contractions with very distant exit sites suspected to have a single origin

Outflow tract premature ventricular contractions sometimes demonstrate multiple exit sites in the right and left outflow tracts with preferential pathways. Here we present a case of outflow tract premature ventricular contractions, which were eliminated by ablation from the right ventricular outflow tract accompanied by additional ablation from the very distant endocardial left ventricular outflow tract. The findings during the ablation indicated there was a single origin with multiple exit sites rather than multiple origins for each QRS morphology. This case illustrates that the preferential pathways can demonstrate very distant multiple exit sites.

Pseudoblock of cavotricuspid isthmus via detouring gap conduction

To detect detouring gap conduction, as demonstrated in this case, 3-D mapping is useful in addition to conventional methods.

Disappearance of an anticoagulation-resistant left atrial appendage thrombus after administration of low-dose pimobendan

Anticoagulation therapy is essential for preventing thrombus formation in the left atrial appendage (LAA) and subsequent ischemic strokes in patients with atrial fibrillation (AF). The complete disappearance of any existing LAA thrombi is crucial before AF ablation. Currently, warfarin and direct oral anticoagulants are widely used for this purpose. However, treatment strategies for anticoagulation-resistant LAA thrombi are not well established. Here, we present a case of an 85-year-old male who was scheduled to undergo AF ablation. He developed an LAA thrombus that was resistant to 300 mg/day of dabigatran. Low-dose pimobendan was prescribed in addition to dabigatran; three months later, the thrombus was dissolved successfully. This case demonstrates the potential efficacy of a low-dose oral inotrope for treating an anticoagulation-resistant LAA thrombus. <Learning objective: Treatment strategies for anticoagulation-resistant left atrial appendage thrombi are not well established. This case demonstrates that a low-dose oral inotrope, such as pimobendan, is capable of dissolving such thrombi and is a potentially useful treatment modality.>.

Reversible Left Ventricular Wall Thickening with Takotsubo Syndrome Sequentially Detected by Cardiac Magnetic Resonance Imaging

Recently, it has been reported that spontaneous left ventricular wall thickening occurs among patients with takotsubo syndrome, which affects the long-term prognosis of such patients due to cerebral and cardiac complications. We herein report two cases of transient left ventricular wall thickening with takotsubo syndrome in which sequential cardiac magnetic resonance imaging revealed the existence of edematous changes in the thickened wall. Notably, a left ventricular aneurysm was detected during the course of ventricular wall thickening and may have played a role in the development of serious complications accompanied by takotsubo syndrome. This is the first case report of left ventricular aneurysm occurring with ventricular wall thickening due to takotsubo syndrome.

Ventricular fibrillation via torsade des pointes of cardiac sarcoidosis with preserved left ventricular ejection fraction

Generally, low left ventricular ejection fraction (LVEF) is a risk for ventricular arrhythmia in patients with cardiac sarcoidosis. We present a case of cardiac sarcoidosis with preserved LVEF that evoked ventricular fibrillation (VF). A 73-year-old woman with VF presented to our emergency department. She had a history of ocular sarcoidosis, with gradual thinning of the basal intraventricular septum. LVEF was 62% on the most recent echocardiography. The electrocardiogram after defibrillation showed complete atrioventricular block (CAVB) with QT segment prolongation and frequent ventricular premature beats. VF via torsade des pointes (TdP) was suspected, and temporary intravenous ventricular pacing and magnesium sulfate infusion suppressed her VF. Cardiac sarcoidosis was diagnosed, and an implantable cardioverter defibrillator was implanted. Patients with cardiac sarcoidosis with CAVB are at risk of evoking VF via TdP regardless of LVEF. If cardiac sarcoidosis is suspected, early diagnosis and risk stratification of ventricular arrhythmia are important.

Platypnea-orthodeoxia Syndrome Diagnosed Using Contrast Transesophageal Echocardiography with Simultaneous SpO2 Monitoring

Platypnea-orthodeoxia syndrome (POS) is a rare condition characterized by interatrial right-to-left shunting that is exacerbated in the upright position. We herein report a 78-year-old woman with POS that remained undiagnosed for 2 years, despite repetitive transthoracic echocardiography (TTE). POS was ultimately diagnosed using contrast transesophageal echocardiography (TEE), which revealed a marked increase in right-to-left shunting in the sitting position, associated with simultaneous desaturation. Therefore, we propose that POS should be considered according to the clinical symptoms, regardless of the repetitive TTE results, and contrast TEE should be performed in both the supine and sitting positions to exclude a diagnosis of POS.

Two-dimensional superconducting state of monolayer Pb films grown on GaAs(110) in a strong parallel magnetic field

Two-dimensional (2D) superconductivity was studied by magnetotransport measurements on single-atomic-layer Pb films on a cleaved GaAs(110) surface. The superconducting transition temperature shows only a weak dependence on the parallel magnetic field up to 14T, which is higher than the Pauli paramagnetic limit. Furthermore, the perpendicular-magnetic-field dependence of the sheet resistance is almost independent of the presence of the parallel field component. These results are explained in terms of an inhomogeneous superconducting state predicted for 2D metals with a large Rashba spin splitting.

Histologic typing of thymoma according to the new World Health Organization classification

The new WHO classification scheme provides a set of simple and easily reproducible morphologic criteria for an accurate and consistent categorization of thymic epithelial tumors. This scheme should facilitate interobserver reproducibility and lead to a more precise assessment of prognosis when used in combination with the staging system.

[Lung cancer]

The five year survival rate of lung cancer patients is only 10% in Japan. The staging system of c-TNM is more important than p-TNM when deciding treatment modality for lung cancer. Compared to other solid cancers, neoadjuvant therapy in lung cancer treatment has a more important position. A clinical protocol study should be carried out with the idea of "intent to treat" and medical oncology will play a more important role in the treatment of lung cancer.

[Clinical study on prostate cancer initially presenting with disseminated intravascular coagulation syndrome]

We experienced five patients with prostate cancer with disseminated intravascular coagulation syndrome (DIC) at the first presentation at Gunma University Hospital and affiliated institutions between 1991 and 1997. Their average age was 68 years, average DIC score at the first presentation was 10 and prostate specific antigen (PSA) level was more than 700 ng/ml. All of them had multiple bone metastases. The therapy for DIC and hormonal therapy for prostate cancer were simultaneously started at the first presentation before prostate needle biopsy, but all patients died. The average number of days from the start of DIC to death was 685 days. The patients initially showed a good response to therapy, but their conditions soon aggravated. The prognosis was extremely poor, but some proper therapies lead to the prognosis which was equal to that of prostate cancer in Stage D2 without DIC.

Leuprorelin acetate blood levels and dialysance after the administration of sustained-release leuprorelin acetate in a dialysis case complicated by prostate cancer

BACKGROUND

The objective of this study is to determine whether in a dialysis patient with prostate cancer leuprorelin acetate blood levels were abnormally high or low due to kidney failure or because of dialysis.

METHODS

Sustained-release leuprorelin acetate 3.75 mg was given every 4 weeks for prostate cancer in a 79-year-old dialysis patient. Changes in serum level of leuprorelin acetate in this patient were measured before and after dialysis.

RESULTS

Leuprorelin acetate appeared to have a dialysance close to that of vitamin B12, which has a similar molecular weight. The amount dialyzed did not exceed 8.3% of the amount released per day. Mean blood levels of leuprorelin acetate, as measured in this patient, were higher (0.64 to 1.31 ng/ml) than those in prostate cancer patients with normal kidney function (mean +/- SD, 0.24 +/- 0.12 to 0.50 +/- 0.32 ng/ml).

CONCLUSIONS

Sustained-release leuprorelin acetate can be used safely in dialysis patients with prostate cancer.

High postprandial plasma remnant-like particles-cholesterol in patients with coronary artery diseases on chronic maintenance hemodialysis

The aim of this study was to determine the levels of postprandial plasma remnant-like particles-cholesterol (RLP-C) in patients with coronary artery disease (CAD) on chronic maintenance hemodialysis (HD). Forty-two patients on chronic maintenance HD with and without CAD were studied. The subjects took a meal within 1 hr before HD then underwent HD for 4 hr with heparin infusion. The plasma level of RLP-C was monitored before and during HD and its biochemical characteristics were analysed. In the CAD group, the RLP-C level was 5.9 +/- 3.5 mg/dl before HD and 6.9 +/- 4.6 mg/dl after HD. In patients without CAD, RLP-C levels before and after HD were 2.1 +/- 0.8 mg/ dl and 2.7 +/- 1.2 mg/dl respectively (within the normal range). The RLP-C levels between CAD and non-CAD were highly significant (p < 0.001). HPLC analysis of RLP revealed that VLDL remnants were reduced to smaller size, cholesterol rich particles within 1 hr of HD and a marked increase in chylomicron (CM) remnants was observed at the end of HD. These observations suggest that a latent metabolic disorder of chylomicrons and VLDL during HD after a meal can be detected by plasma RLP-C assay. The association between the frequency of latent metabolic lipoprotein disorders and CAD found in HD patients may require appropriate dietary intervention together with drugy therapy for the control of CAD.

Quantification of the Na+/K(+)-pump in solubilized tissue by the ouabain binding method coupled with high-performance gel chromatography

Membrane-bound Na+/K(+)-ATPase purified from dog kidney outer medulla was solubilized with octaethylene glycol n-dodecyl ether (C12E8) and incubated with [3H]ouabain in the presence of NaCl. ATP and MgCl2 for 10 min at 0 degrees C. The resulting enzyme was separated, by high-performance gel chromatography executed at 0.2 degrees C. Mainly into its (alpha beta)2-diprotomer and alpha beta-protomer, which both bound stoichiometrically to [3H]ouabain. The amounts of ouabain that bound to the tissue itself and its microsomes could be estimated in the same way, as [3H]ouabain was found to bind only to the diprotomer and protomer they possessed. The amounts of ouabain that bound to them in the solubilized state were at least 5-times higher than those that did so when they were non-solubilized, suggesting that the surfactant rendered the enzyme accessible to ouabain. When the solubilized tissue (138 mg ml-1 wet tissue) was reacted with ouabain in the presence of 0.1 M NaCl and 4.8 mM MgCl2 for 10 min at 0 degrees C, maximal ouabain binding was attained in the presence of 18.3 microM [3H]ouabain, 1.2 mM ATP and 3 to 5 mg ml-1 C12E8, which was common to the outer medulla and human colon cancer cells. The present method enabled the pump number in protein and tissue samples in the range 7.2 x 10(-9) (purified pump) to 1.5 x 10(-12) (cancer tissue) mol/mg protein to be estimated within 2 h.

Renocolic fistula caused by xanthogranulomatous pyelonephritis

A 68-year-old female was diagnosed with a renocolic fistula, associated with left chronic pyelonephritis due to a ureter stone. Nephrectomy and repair of the fistula were performed. Histopathological examination revealed xanthogranulomatous pyelonephritis.

Increased urinary dopamine excretion in young patients with essential hypertension

The evidence that some older patients with essential hypertension have low urinary dopamine excretion has brought into question the levels of urinary dopamine and plasma dopa, the major source of urinary dopamine, in young patients with essential hypertension. Twenty-four-hour urine sodium, creatinine, dopamine and noradrenaline and plasma dopa were evaluated in 48 patients with essential hypertension aged 18 to 27 years and 25 normotensive subjects. In comparison with age-matched normotensive subjects, the hypertensive patients had higher urinary dopamine (1920 +/- 80 vs 1520 +/- 130 nmol/day, p < 0.01) and noradrenaline (216 +/- 11 vs 179 +/- 12 nmol/day, p < 0.05) excretion. There was a significant correlation between urinary dopamine and noradrenaline excretion. There was no difference in plasma dopa levels between normotensive and hypertensive subjects. These results suggest that the elevated conversion of dopa to dopamine in the kidney is leading to increased urinary dopamine excretion in young patients with essential hypertension.

[Symptoms and signs of benign prostate hypertrophy (BPH)]

Clinical characteristics of BPH were investigated in the relationship among prostate volume estimated by transrectal sonography, symptoms by questionnaire, residual urine volume, and voiding force evaluated by uroflowmetry. There was no apparent relationship among them, which might be caused by the poor reproducibility of residual urine volume, the difficult enumeration of the symptoms, contamination of other diseases of which voiding disorder is correlated with aging and other unknown factors. Under such a situation, this disease should be treated as a BPH syndrome. Moreover we propose that BPH syndrome should be classified into three types; type 1: symptomatic BPH without enlarged prostate, type 2: asymptomatic BPH with enlarged prostate and type 3: symptomatic BPH with enlarged prostate.

The role of intraabdominal pressure in venous blood drainage from the prostate into the vertebral vein system

We investigated venous blood drainage from the prostate into the vertebral vein system by cineangiography in five mongrel dogs and measured intraabdominal pressure and venous blood pressure in the dog or human to study the role of intraabdominal pressure in the drainage. The averages of intraabdominal pressure and caudal vena caval pressure in the dog were 32.2 +/- 3.0 and 12.8 +/- 1.3 mmHg, respectively, in the supine position, and 39.2 +/- 3.0 and 23.8 +/- 4.0 mmHg, respectively, in the head-up tilt position, when the radiopaque medium injected into the dorsal penile vein appeared in the vertebral vein system. Intraabdominal pressure in the head-up tilt position was significantly higher than that in the supine position when the venous drainage into the vertebral veins happened. In eight continuous ambulatory peritoneal dialysis patients, intraabdominal pressure showed 8.1 +/- 2.4 mmHg in the supine position, 24.6 +/- 4.3 mmHg in the sitting position, and 30.4 +/- 4.9 mmHg in the standing position at rest. During voluntary contraction of the abdominal muscles, the pressure was increased up to 50.6 +/- 21.6 mmHg in the supine position, 69.3 +/- 19.8 mmHg in the sitting position, and 73.8 +/- 19.8 mmHg in the standing position. These pressure values in the human were significantly higher than those observed at the time when the radiopaque medium appeared in the vertebral veins in both supine and head-up tilt positions in the canine. These results suggest that the increase of intraabdominal pressure causes inflow of prostatic venous blood into the vertebral veins via the inferior vena cava, common iliac vein, or internal iliac vein.

Leisure time physical activity and insulin resistance in young obese students with hypertension

To investigate the hypothesis that insulin resistance plays a role in the etiology of hypertension and hyperlipidemia, we measured serum lipid levels, the fasting glucose/insulin ratio, and the insulin response to oral glucose (GTT) in a group of young obese subjects (n = 21) with hypertension and normal glucose tolerance and in normotensive subjects (n = 36) with normal glucose tolerance, matched for age and body mass index. Leisure time physical activity was evaluated by a questionnaire outlining three levels of physical activities during leisure time. Subjects with hypertension had higher fasting serum insulin (19 +/- 2 v 13 +/- 1 microU/mL, P < .01) and lower fasting glucose/insulin ratio (5.3 +/- 0.2 v 7.1 +/- 0.5 mg/dL/microU/mL, P < .01) than normotensive subjects. Subjects with hypertension had higher peak serum insulin and lower plasma glucose area/insulin area ratio in response to glucose (1.8 +/- 0.2 v 2.4 +/- 0.2 mg/dL/microU/mL, P < .05) than normotensive subjects. Serum total cholesterol, low-density cholesterol, and triglycerides were higher in the obese hypertensive subjects than in obese normotensive ones. Blood pressure correlated with either fasting serum insulin, fasting glucose/insulin ratio, or glucose area/insulin area ratio during GTT. The level of leisure time physical activities was lower in obese hypertensive subjects than in obese normotensive ones. There were significant correlations between the levels of physical activity and the fasting plasma glucose/insulin ratio (r = 0.371, P < .01) or the fasting serum insulin concentration (r = -0.282, P < .05). The study provided evidence that a low level of leisure time physical activity is associated with insulin resistance and resultant hyperinsulinemia, which are the key metabolic abnormalities that link hypertension, obesity, and hyperlipidemia in young subjects.

[A case of shock following intravesical formalin instillation]

A case of shock following intravesical formalin instillation for massive bladder hemorrhage owing to post-radiation cystitis is reported. A 79-year-old woman had been treated with external irradiation for cancer of the uterine body in 1981. She was suffering from massive hematuria after hysterectomy in 1988. No hemostatic procedures were effective. Then we instilled 10% formalin into her bladder. After the instillation she entered a state of allergic shock.

[Double filtration plasma pheresis was effective on the recurrence of pulmonary hemorrhage after renal transplantation: report of a case]

A 35-year old female with an autoimmune disease complaining of recurrent hemoptysis and macrohematuria had received a renal transplantation from her mother. After transplantation, recurrence of pulmonary hemorrhage occurred twice. First recurrence followed the peritonitis with ileal perforation. Steroid pulse therapy had no effect on this recurrence, while double filtration plasmapheresis was effective. During this treatment, renal function was not failed. Second recurrence followed acute rejection that was cured with the OKT3-rescue therapy. DFPP therapy was effective on this episode. Pulmonary hemorrhage was caused by auto immune reaction and acute rejection caused by transplant immune reaction were recognized independently, and they needed different treatment. According to this clinical course, we consider the relation between auto immune reaction and transplant immune reaction was as follows. T cell activation caused by primary transplant immune reaction may have no direct influence on auto immune reaction. Peritonitis and rejection may induce auto immune reaction. We suppose that this auto immune reaction was caused by humoral factor, because auto immune reaction was controlled by DFPP.

Effect of L-dopa in young patients with hypertension

The effects of L-dopa on blood pressure, heart rate, plasma renin activity, norepinephrine, epinephrine and prolactin were studied in a randomized single-blind trial in 36 patients with essential hypertension. In response to L-dopa, 250 mg administered orally, the blood pressure decreased significantly as compared with the results of placebo treatment. The heart rate and plasma norepinephrine and epinephrine were unchanged. The plasma renin activity and prolactin decreased as a result of L-dopa administration. The administration of a peripheral DA2 dopamine receptor blocker, domperidone (20 mg, orally) prevented the L-dopa-induced reduction in plasma prolactin but failed to block the fall in blood pressure and plasma renin activity. These results suggest that the blood pressure-lowering effect of L-dopa may be mediated through multiple sites involving D1 dopamine receptors, the central nervous system, and the renin-angiotensin system.