A case of ventricular fibrillation as a consequence of capecitabine-induced secondary QT prolongation: A case report.

Capecitabine is an oral fluoropyrimidine which can prolong QT interval. However, there have been no reports that capecitabine induced ventricular fibrillation (VF) due to secondary QT prolongation in patients with no structural heart disease. A 39-year-old woman developed VF during the chemotherapy of capecitabine for colon cancer. At the administration, corrected QT interval (QTc) was prolonged to 559 ms despite no evidence of organic heart disease. Discontinuation of capecitabline normalized the QTc (414 ms). During the follow-up of eight years, neither the QTc prolongation nor the recurrent VF has been detected. We report the rare case of capecitabine-related VF without any organic heart disease. .

The mechanism of mitral regurgitation assessed by preprocedural echocardiography is associated with the outcome of catheter ablation in patients with paroxysmal atrial fibrillation.

BACKGROUND: Mitral regurgitation (MR) is generally classified as either primary (organic) or secondary (functional). Although patients with atrial fibrillation (AF) often exhibit MR, the relation between the etiology of MR and the outcome of catheter ablation (CA) remains unknown. We conducted this study in order to elucidate this association. METHODS: Among 1330 consecutive paroxysmal AF patients who underwent initial catheter ablation in our institution, 92 patients (62 men, mean age 65 ± 7 years) who had moderate or severe MR were included in this study; 46 were classified to have primary and the remaining 46 to have secondary MR by preoperative echocardiography. These patients were prospectively monitored after the CA. RESULTS: During a mean follow-up period of 27.9 ± 28.8 months, AF recurred in 26/46 (56.6 %) of primary MR patients and in 15/46 (32.6 %) of those with secondary MR (P < 0.02). Although univariate analysis found that diabetes, left atrial volume indexed by body surface area (LAVI), and primary MR were significantly associated with AF recurrence, primary MR (hazard ratio (HR), 2.47; 95 % confidence interval (CI), 1.30-4.88; P = 0.006) and LAVI (HR, 1.03/1 mL/m(2) increase; 95 % CI, 1.00-1.06; P = 0.03) remained significant predictors on multivariate analysis. The AF recurrence-free rate was lower in patients with primary MR after both the initial and final CA. CONCLUSION: In patients with paroxysmal AF and moderate or severe MR, primary MR may increase the risk of AF recurrence after the initial and final CA.

Rapid Mapping of Right Atrial Tachycardia Using a New Multielectrode Basket Catheter.

INTRODUCTION: The mapping of atrial tachycardia (AT) can often be challenging and time-consuming, especially in patients with ATs that develop following cardiac surgery or are concomitant with atrial fibrillation. Recently, a new multielectrode basket catheter (MBC) has become available; we hypothesized that the MBC could be utilized to diagnose AT circuits. METHODS AND RESULTS: This study included 51 consecutive patients undergoing catheter ablation of clinically documented right-sided ATs (including 17 cases following cardiac surgery). Using a NavX system, 2 activation maps of the ATs were created, one using the new MBC (32 mm, 31 poles) and the other using a circular catheter. The time needed to complete the activation maps and the points acquired with both mapping catheters were compared. In all 64 ATs, including 34 non-cavotricuspid isthmus-dependent ATs, the AT activation maps created by both catheters were essentially identical. The number of points acquired to complete the activation maps did not differ significantly between the MBC and the circular catheter (387 [285-511] vs. 374 [269-533], P = 0.19), but the mapping time was significantly shorter using the MBC (4.0 [3.0-6.0] minutes vs. 8.0 [6.5-10.0] minutes, P < 0.0001). Inadvertent mechanical AT termination (n = 6) was observed only during mapping with the circular catheter. CONCLUSION: In patients with right-sided ATs, the use of an MBC could save mapping time.

Impact of Non-Pulmonary Vein Foci on the Outcome of the Second Session of Catheter Ablation for Paroxysmal Atrial Fibrillation.

BACKGROUND: Paroxysmal atrial fibrillation (AF) is primarily triggered by pulmonary veins (PVs). However, non-PV AF foci may also trigger AF. METHODS: We examined 207 patients (mean age, 62 ± 11 years; 166 men) who underwent a second catheter ablation (CA) and evaluated the clinical significance of non-PV AF foci on the outcomes. RESULTS: Electrical reconnections between the PVs and left atrium (LA) were observed in 162 patients (78.3%). Non-PV AF foci were identified in 95 patients (45.9%, 60 patients with successfully ablated non-PV AF foci and 35 with unmappable non-PV AF foci). During a median follow-up period of 22.7 months, 61 patients (29.5%; 18/112 [16.1%] without non-PV AF foci vs. 20/60 [33.3%] with successfully ablated non-PV AF foci vs. 23/35 [65.7%] with unmappable non-PV AF foci, P < 0.0001) developed AF recurrence; 52 (85.2%) developed recurrence within 1 year. The presence of non-PV AF foci was a significant clinical predictor of AF recurrence after the second CA; successfully ablated non-PV AF foci increased the AF recurrence risk by 2.24 times (95% confidence interval [CI], 1.12-4.54; P = 0.02), and unmappable AF foci increased this risk by 5.58 times (95% CI, 2.73-11.63; P < 0.0001). CONCLUSION: Nearly half of the patients had non-PV AF foci at the second CA session. AF recurred after the second CA session in approximately 30%, with most recurrences happening within 1 year. The presence of non-PV AF foci significantly increased the AF recurrence risk after a second CA. When non-PV AF foci were unmappable, the AF recurrence rate was extremely high.

Incidences of esophageal injury during esophageal temperature monitoring: a comparative study of a multi-thermocouple temperature probe and a deflectable temperature probe in atrial fibrillation ablation.

PURPOSE: The study aim was to compare the incidence of esophageal injuries between different temperature probes in the monitoring of esophageal temperature during atrial fibrillation (AF) ablation. METHODS: One hundred patients with drug-resistant AF were prospectively and randomly assigned into two groups according to the esophageal temperature probe used: the multi-thermocouple probe group (n = 50) and the deflectable temperature probe group (n = 50). Extensive pulmonary vein (PV) isolation was performed with a 3.5-mm open irrigated tip ablation catheter by using a radiofrequency (RF) power of 25-30 W. In both groups, the esophageal temperature thermocouple was placed on the area of the esophagus adjacent to the ablation site. When the esophageal temperature reached 42 °C, the RF energy delivery was stopped. Esophageal endoscopy was performed 1 day after the catheter ablation. RESULTS: No differences existed between the two groups in terms of clinical background and various parameters related to the catheter ablation, including RF delivery time and number of RF deliveries at an esophageal temperature of >42 °C. Esophageal lesions, such as esophagitis and esophageal ulcers, occurred in 10/50 (20 %) and 15/50 (30 %) patients in the multi-thermocouple and deflectable temperature probe groups, respectively (P = 0.25). Most lesions were mild to moderate injuries, and all were cured using conservative treatment. CONCLUSION: The incidence of esophageal injury was almost equal between the multi-thermocouple temperature probe and the deflectable temperature probe during esophageal temperature monitoring. Most of the esophageal lesions that developed during esophageal temperature monitoring were mild to moderate and reversible.

Primary diffuse large B-cell lymphoma of the bladder.

Primary lymphoma of the bladder is quite rare; primarily, it is extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT-lymphoma). There is only one case report of primary diffuse large B-cell lymphoma (DLBCL) of the bladder, accompanied by diffuse wall thickening of the bladder. Here, we report a second case of primary DLBCL of the bladder in a 75-year-old woman patient, whose initial presentation was acute renal failure. Three courses of R-CHOP chemotherapy were effective to treat acute renal failure caused by post-renal obstruction and to attain clinical remission.

Propagation of adult rat bone marrow-derived hepatocyte-like cells by serial passages in vitro.

Previously, we found that hepatocyte growth factor receptor (c-Met)-and alpha-fetoprotein (AFP)-expressing cells were present in adult rat bone marrow, and that these cells also expressed hematopoietic stem cell markers, such as CD34, Thy-1, and c-Kit. When bone marrow cells were cultured in a hepatocyte growth medium (HGM) with HGF and EGF, colonies composed of polygonal cells resembling mature hepatocytes appeared by 2 weeks and grew very slowly because of overgrowth of stromal cells. At days 34-41, 2-mm2 sheets of hepatocyte-like cells were cut out of their colonies by scratching with an injection needle under observation with a phase contrast microscope, transferred into wells of 24-well plates, and cultured in the HGM medium in the presence or absence of HGF and EGF. When cells reached confluence, cells were detached with trypsin and EDTA and transferred step by step into bigger culture vessels. Thus, hepatocyte-like cells were expanded 1000-fold during less than 4 months. These cells were immunocytochemically stained for albumin and also for AFP and the hematopoietic stem cell markers described above, showing characteristics of oval cells. By RT-PCR, we detected mRNAs of tryptophan-2,3-dioxygenase and tyrosine aminotransferase, markers of hepatocytes at a terminal differentiation stage. The present culture system may be useful for supply of hepatocyte resources for cell transplantation therapy.

Improved conditions to induce hepatocytes from rat bone marrow cells in culture.

Recent studies have revealed that bone marrow cells can develop into hepatocytes by in vivo transplantation under certain circumstances. However, little is known about the mechanism of bone marrow cell differentiation into hepatocytes. It is important to determine suitable culture conditions in which bone marrow cells will be differentiated into hepatocytes not only for understanding differentiation mechanisms but also for efficient amplification of hepatocyte-progenitor cells of bone marrow origin, this being a prerequisite for potential therapeutic use. In the present study, we found that hepatocyte growth factor (HGF) receptor (c-Met)- and alpha-fetoprotein-expressing cells were present in adult rat bone marrow. We also found that these cells also express hematopoietic stem cell markers, such as CD34, Thy-1, and c-Kit. Using an HGM medium with HGF and EGF, we succeeded in propagating hepatocyte-like cells induced from adult rat bone marrow in culture. These cells were immunocytochemically stained for albumin. By RT-PCR analysis of cultures containing the hepatocyte-like cells, we detected mRNAs of tryptophan-2,3-dioxygenase and tyrosine aminotransferase, markers of hepatocytes at a terminal differentiation stage. The present culture therefore can be a useful resource for cell transplantation therapy for liver diseases.