Incisional atrial reentrant tachycardia: experimental study on the conduction property through the isthmus

AbstractBackgroundIncisional atrial reentrant tachycardia is a life-threatening tachyarrhythmia after surgery for congenital heart disease. Slow conduction through an isthmus between anatomical barriers, such as a right atriotomy or the sites for cannulation, has been shown to be a prerequisite for perpetuation of the incisional atrial reentrant tachycardia. However, the conduction property through the isthmus has not been examined in detail.MethodsTo examine the conduction property, 2 tandem incisions were made on the lateral right atrium with various distances (3 to 20 mm) between the incisions in 16 canines. Four weeks after the surgery, the lateral right atrium was mapped epicardially during pacing to examine the conduction property through the isthmus. The conduction property was characterized by approximated curves of the conduction velocity through the isthmus in accordance with the pacing cycle lengths. The atrial tissue at the isthmus was examined microscopically.ResultsThe approximated curves of the conduction velocity were classified into 3 different types. Decremental conduction was observed only in the isthmi between 5 and 15 mm in width. A small amount of surviving myocardium between the scars formed the critical isthmus microscopically (decremental type). In the isthmi wider than 15 mm in width, slow conduction was not seen at any paced cycle length (nondecremental type). In the extremely narrow isthmi less than 5 mm in width, all of the atrial myocardium at the isthmus was replaced by fibrous tissue. Conduction was blocked at the isthmus and the activation detoured around the incisions (block type). There was a statistically significant difference in the approximated curves between the 3 different types of conduction properties (P < .01).ConclusionThe width of the isthmus determines the conduction property through the isthmus that contributes to the development of the incisional atrial reentrant tachycardia. Thus, the incisional atrial reentrant tachycardia may be preventable by leaving a sufficient amount of surviving myocardium between the incisions or by connecting the incisions by an ablative procedure

Map-guided surgery for atrial fibrillation

BackgroundAlthough current surgical procedures result in a high success rate for atrial fibrillation, they are not guided by electrophysiologic findings in individual patients and thus might include unnecessary incisions in some patients or be inappropriate for other patients. We sought to determine whether intraoperative mapping is beneficial for the surgical treatment of atrial fibrillation.MethodsA 256-channel 3-dimensional dynamic mapping system with custom-made epicardial patch electrodes was used to examine the atrial activation during atrial fibrillation and to determine the optimal procedure in 37 patients with continuous and 9 patients with intermittent atrial fibrillation intraoperatively.ResultsSurgical intervention for atrial fibrillation was not indicated in 3 patients in whom the atrial electrograms had a low voltage over a broad area. Concurrent, multiple, and repetitive activations arising from the pulmonary veins or left atrial appendage were observed in all patients. A simple left atrial procedure consisting of pulmonary vein isolation and left atrial incisions without any right atrial incisions was performed in 8 patients in whom the right atrial activation was passive, and all (100%) were cured of atrial fibrillation. The radial procedure was performed in the remaining 35 patients, and 31 (89%) of the patients were cured of atrial fibrillation. In this subset of patients, 10 exhibited reentrant or focal activation in the posterior left atrium between the right and left pulmonary veins and required an additional linear ablation on the posterior left atrium. The total amount of postoperative bleeding after the simple left atrial procedure was significantly less than after the radial procedure (378 ± 135 vs 711 ± 364 mL, P = .03). The right and left atrial transport functions were well preserved after both the radial and simple left atrial procedures.ConclusionIntraoperative mapping facilitates determining the optimal procedure for atrial fibrillation in each patient

Oral carcinoma: Clinical evaluation using diffusion kurtosis imaging and its correlation with histopathologic findings

PURPOSE: In this study, we aimed to determine the usefulness of diffusion kurtosis imaging (DKI) as a noninvasive method for evaluation of the histologic grade and lymph node metastasis in patients with oral carcinoma. MATERIALS AND METHODS: Twenty-seven patients with oral carcinoma were examined with a 3-T MR system and 16-channel coil. DKI data were obtained by a single-shot echo-planar imaging sequence with repetition time, 10,000ms; echo time, 94ms; field of view, 250x204.25ms; matrix, 120x98; section thickness, 4mm; four b values of 0, 500, 1000, and 2000s/mm(2); and motion-probing gradients in three orthogonal directions. Diffusivity (D) and kurtosis (K) were calculated using the equation: S=S0 exp(-b D+b(2) D(2) K/6). Conventional apparent diffusion coefficient (ADC) was also calculated. The MR images were compared with the histopathologic findings. RESULTS: Relative to the histologic grades (Grades 1, 2, and 3) of the 27 oral carcinomas, D values showed a significant inverse correlation (r=-0.885; P<0.001) and K values showed a significant positive correlation (r=0.869; P<0.001), whereas ADC values showed no significant correlation (r=-0.311; P=0.115). When comparing between metastatic and non-metastatic lymph nodes, significant differences in the D values (P<0.001) and K values (P<0.001), but not the ADC values (P=0.110) became apparent. CONCLUSIONS: In patients with oral carcinoma, DKI seems to be clinically useful for the evaluation of histologic grades and lymph node metastasis

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Anaesthetic management of an abdominal aortic aneurysmorrhaphy in Klippel-Trenaunay-Weber syndrome: a case report

Abstract Background Klippel-Trenaunay-Weber syndrome (KTWS) is a rare congenital malformation. Although there have been few reports on anaesthetic management of patients with KTWS, there is a lack of data on anaesthetic management for abdominal aortic aneurysm (AAA) surgeries in these patients. Case presentation A 74-year-old man (height, 160 cm and body weight, 51.5 kg) with KTWS was scheduled for AAA replacement. Abdominal computed tomography (CT) showed prominent tortuosity below the abdominal aorta with an infrarenal abdominal aortic aneurysm, right common iliac artery aneurysm, and right external iliac artery aneurysm. Moreover, a remarkably noted arteriovenous fistula had developed between the aneurysm and peripheral artery. General anaesthesia was induced. Furthermore, a central venous catheter and an 8.5 French sheath in the left internal jugular vein were inserted. During the operation, bleeding from a collateral vessel in the cross-clamped aorta led the surgeon to decide to perform aneurysmorrhaphy. Intraoperatively, blood loss was 1500 ml, and 20 units of red blood cell concentrate were used. Conclusions Regarding AAA procedures in patients with KTWS, aortic cross-clamping may not sufficiently intercept blood flow due to collateral vessels. In these patients, the anaesthesiologist must be prepared to transfuse blood more rapidly and frequently than during normal AAA procedures

Surgical treatment of atrial fibrillation: State of the art, 2012

The development and introduction of radiofrequency ablation devices allowed maze procedure to be performed safely and easily, further enabling off-pump pulmonary vein isolation through mini-thoracotomy or thoracoscopy. The outcomes of the maze procedure include the prevention of stroke and other complications related to atrial fibrillation (AF), improvement in cardiac performance, and relief of symptoms. The indications for the maze procedure have been discussed on the basis of available evidence. Pulmonary vein isolation has been shown to be effective in most patients with paroxysmal AF, and can be performed with both endocardial catheter ablation and minimally invasive epicardial ablation. These 2 modalities should be compared in terms of the success rate, occurrence of cerebral microembolic signals, capability adding other lesions indicated for persistent or long-standing persistent AF, and closure of the left atrial appendage. Noncontinuous or nontransmural lines of conduction block as a result of incomplete ablation can result in the recurrence of AF and induction of atrial tachycardia. Intraoperative verification of a conduction block across the ablation lines is recommended to prevent these complications. Volume reduction of the enlarged left atrium or a box lesion to isolate the entire posterior left atrium may be effective in patients with a dilated left atrium, but the potentially impaired atrial transport function should be considered. Mapping of active ganglionated plexi and their ablation may improve the outcome of the procedure; however, the long-term effect on AF and autonomic nerve activities should be examined. Because the mechanism underlying AF varies in each patient, a tailor-made therapy, using a stepwise approach, with a hybrid procedure combining epicardial and endocardial ablation offers promising prospects in the nonpharmacological treatment of AF

Bovine three-portion pericardial patch for reconstruction of the aorto-mitral curtain in infective endocarditis

Abstract Background Surgery for infective endocarditis involving the aorto-mitral curtain (AMC) is challenging and requires extensive incisions and complex reconstruction procedures. However, in patients with preserved aortic annulus, reconstruction of the AMC is possible using a simple technique with limited incisions. Case presentation A handmade bovine three-portion pericardial patch was used to reconstruct the AMC in a patient with severe endocarditis requiring double valve replacement; the technique allowed for steady anchorage of prosthetic valves without additional incisions other than conventional aortotomy and atriotomy. Postoperative echocardiography revealed normal cardiac function and no significant perivalvular leakage. The patient displayed complete recovery and was discharged on postoperative day 33. The patient was symptom-free at his 1-year follow-up and displayed normal laboratory and echocardiographic findings. Conclusion The bovine three-portion pericardial patch is useful for reconstructing the AMC in patients with infective endocarditis accompanied by preserved aortic annulus