Bleeding sites and treatment strategies for cardiac tamponade by catheter ablation requiring thoracotomy: risks of catheter ablation in patients with left atrial diverticulum.

BACKGROUND: There is insufficient information regarding the bleeding sites and surgical strategies of cardiac tamponade during catheter ablation for atrial fibrillation (AF). CASE PRESENTATION: Of the five patients with cardiac tamponade, three required surgical intervention and two required pericardiocentesis. In the first case of three cardiac tamponades requiring surgical intervention, considering that the peripheral route was used, the catecholamines did not reach the heart, and due to unstable vital signs, venoarterial extracorporeal membrane oxygenation (VA-ECMO) was inserted. No bleeding point was identified, but a thrombus had spread around the left atrium (LA) with diverticulum. Hemostasis was achieved with adhesives placed around the LA under on-pump beating. In the second case, pericardiocentesis was performed, but the patient showed heavy bleeding and unstable vital signs. Thus, VA-ECMO was inserted. Heavy bleeding was expected, and safety was enhanced by attaching a reservoir to the VA-ECMO. The bleeding point was found between the left upper pulmonary artery and LA under cardiac arrest to obtain a good surgical view for suturing repair. In the third case, the LA diverticulum was damaged. Pericardiocentesis resulted in stable vitals, but sustained bleeding was present. A bleeding point was found at the LA diverticulum, and suture repair under on-pump beating was performed. CONCLUSIONS: When cardiac tamponade occured in any patient with LA diverticulum, treatment could not be completed with pericardiocentesis alone, and thoracotomy was likely to be necessary. If the bleeding point could be confirmed, suturing technique is a more reliable surgical strategy than adhesive alone that leads to pseudoaneurysm. If the bleeding point is unclear, it is important to confirm the occurrence of LA diverticulum using a preoperative CT, and if confirmed, cover it with adhesive due to a high possibility of diverticulum bleeding. The necessity of CPB should be determined based on whether these operations can be completed while maintaining vital stability.

Transient decrease in the depth of the negative T wave in apical hypertrophic cardiomyopathy is a sign of left anterior descending artery stenosis: a case series.

Background: In patients with apical hypertrophic cardiomyopathy (HCM), electrocardiography (ECG) often shows left ventricular hypertrophy (LVH) and a negative T wave. A negative T wave often disappears over time due to degeneration of the apical myocardium. However, there are limited reports on the temporary change of a negative T wave in patients with HCM. Case summary: We report three apical HCM patients with LVH and T wave inversion on their previous ECG who showed a temporary decrease in the depth of the negative T wave. All of them had significant stenosis of coronary arteries including the left anterior descending artery (LAD). After revascularization for the LAD lesion, their ECG returned to the previous depth of the negative T wave. Discussion: The cases presented here suggested that a temporary decrease in the depth of the negative T wave in apical HCM patients may be one of the signs of ischaemia in the anterior-apical region caused by severe stenosis of the LAD.

Systemic delivery of siRNA to the colon using peptide modified PEG-PCL polymer micelles for the treatment of ulcerative colitis.

Ulcerative colitis (UC) is a refractory inflammatory bowel disease that causes inflammation and ulcers in the digestive tract, and significantly reduces the patient's quality of life. While existing UC treatments have many challenges, nanotechnology, and small interfering RNA (siRNA) based formulations are novel and promising for UC treatment. We previously reported that intravenous administration of MPEG-PCL-CH2R4H2C nanomicelles had high inflammatory site accumulation and remarkable therapeutic effects on rheumatoid arthritis by a phenomenon similar to enhanced permeability and retention effect. In this study, we investigated the effects of siRNA delivered using MPEG-PCL-CH2R4H2C nanomicelles through intravenous administration to the inflammation site of dextran sulfate sodium-induced colitis mice. The MPEG-PCL-CH2R4H2C micelles had optimum physical properties and high siRNA compaction ability. Moreover, model-siRNA delivered through MPEG-PCL-CH2R4H2C showed higher accumulation in the inflammatory site than that of the naked siRNA. Furthermore, intravenous administration of MPEG-PCL-CH2R4H2C/siRelA micelles, targeting siRelA, a subunit of NF-κB, significantly decreased the shortening of large intestine, clinical score, and production of inflammatory cytokines compared the 5-ASA and naked siRelA. These results suggest that MPEG-PCL-CH2R4H2C is a useful carrier for the systemic delivery and accumulation of siRNA, thus improving its therapeutic effect.

In Vivo Fluorescence Imaging of Passive Inflammation Site Accumulation of Liposomes via Intravenous Administration Focused on Their Surface Charge and PEG Modification.

Nanocarriers such as liposomes have been attracting attention as novel therapeutic methods for inflammatory autoimmune diseases such as rheumatoid arthritis and ulcerative colitis. The physicochemical properties of intravenously administered nanomedicines enable them to target inflamed tissues passively. However, few studies have attempted to determine the influences of nanoparticle surface characteristics on inflammation site accumulation. Here, we aimed to study the effects of polyethylene glycol (PEG) modification and surface charge on liposome ability to accumulate in inflammatory sites and be uptake by macrophages. Four different liposome samples with different PEG modification and surface charge were prepared. Liposome accumulation in the inflammation sites of arthritis and ulcerative colitis model mice was evaluated by using in vivo imaging. There was greater PEG-modified than unmodified liposome accumulation at all inflammation sites. There was greater anionic than cationic liposome accumulation at all inflammation sites. The order in which inflammation site accumulation was confirmed was PEG-anionic > PEG-cationic > anionic > cationic. PEG-anionic liposomes had ~2.5× higher fluorescence intensity than PEG-cationic liposomes, and the PEG-liposomes had ~2× higher fluorescence intensity than non-PEG liposomes. All liposomes have not accumulated at the inflammation sites in healthy mice. Furthermore, cationic liposomes were taken up to ~10× greater extent by RAW264.7 murine macrophages. Thus, PEG-cationic liposomes that have the ability to accumulate in inflammatory sites via intravenous administration and to be taken up by macrophages could be useful.

What we believed to be a right upper pulmonary vein by transthoracic echocardiography is actually a right lower pulmonary vein.

BACKGROUND: Current guidelines recommend that pulmonary vein (PV) velocity should be recorded by using the right upper pulmonary vein (RUPV) during transthoracic echocardiography (TTE) evaluation of left ventricular diastolic function. However, it is uncertain whether the PV displayed during TTE is truly measuring the upper PV. This study aimed to identify the actual site of each PV that is usually detected during TTE. METHODS: We retrospectively studied 105 patients who underwent cardiac computed tomography (CT) and TTE, reconstructed images three-dimensionally, and measured the angles between each PV and the left ventricle (LV) that would correspond to the Doppler incident angle of the apical four-chamber view on TTE. We also performed TTE during catheter ablation to confirm the exact site of the PV. RESULTS: Apical four-chamber views on TTE revealed that one certain PV was detectable on the right side of the vertebra. CT scans revealed that the median angle of the axes between the LV and right lower pulmonary vein (RLPV) was smaller than that of RUPV {32.1˚ [interquartile range (IQR): 21.7˚-42.1˚] vs. 62.5˚ (IQR: 51.6˚-70.6˚), P < .001}. During catheter ablation for treatment of atrial fibrillation, in the most well-displayed PV on TTE, we detected the ablation catheter placed in the RLPV. CONCLUSIONS: The most well-displayed PV in an apical four-chamber view by TTE was not the RUPV but the RLPV which showed the smallest angle of incidence toward the LV apex. The RLPV is suitable for evaluation of PV velocity to assess LV diastolic function.

Knockout of the interleukin-36 receptor protects against renal ischemia-reperfusion injury by reduction of proinflammatory cytokines.

IL-36, a newly named member of the IL-1 cytokine family, includes 3 isoforms, IL-36α, IL-36ß, and IL-36γ, all of which bind to a heterodimer containing the IL-36 receptor (IL-36R). Little is known about the role of the IL-36 axis in acute kidney injury (AKI) pathogenesis. Therefore, we evaluated IL-36 function in the bilateral renal ischemia-reperfusion injury model of AKI using IL-36R knockout and wild-type mice. IL-36R was found to be expressed in the kidney, mainly in proximal tubules. In IL-36R knockout mice, plasma creatinine, blood urea nitrogen, and IL-6 levels after ischemia-reperfusion injury were significantly lower than those in wild-type mice. Immunohistological analysis revealed mild tubular injury. IL-36α/ß/γ levels were increased after ischemia-reperfusion injury, and IL-36α was expressed in lymphocytes and proximal tubular cells, but post-ischemia-reperfusion injury mRNA levels of IL-6 and TNF-α were low in IL-36R knockout mice. In primary cultures of renal tubular epithelial cells, IL-36α treatment upregulated NF-κB activity and Erk phosphorylation. Notably, in patients with AKI, urine IL-36α levels were increased, and IL-36α staining in renal biopsy samples was enhanced. Thus, IL-36α/IL-36R blockage could serve as a potential therapeutic target in AKI.

Systemic delivery of small interfering RNA targeting nuclear factor κB in mice with collagen-induced arthritis using arginine-histidine-cysteine based oligopeptide-modified polymer nanomicelles.

This study aimed to build an innovative system to deliver a systemic small interfering RNA (siRNA) treatment for rheumatoid arthritis. We combined arginine-histidine-cysteine based oligopeptide-modified polymer micelles with siRNA targeting the nuclear factor κB subunit, RelA (siRelA). This is a key molecule in the control of inflammation. We tested the cellular uptake of siRNA and its effects on inflammatory cytokine levels in vitro using synoviocytes, and siRNA distribution and therapeutic effects in vivo in mice with collagen-induced arthritis (CIA). These studies showed that arginine-histidine based oligopeptide modified micelles produced effective cellular siRNA uptake and suppressed inflammatory cytokine levels in synoviocytes. In vivo, these micelles produced marked accumulation of siRNAs in arthritic paws in CIA mice, with much less accumulation in healthy mice. The siRelA-polymer micelle complexes also produced more effective suppression of RelA mRNA expression and inflammatory cytokine levels in the arthritic paws of CIA mice and reduced their clinical symptom scores and paw thickness.