The Current Landscape of Ventricular Tachycardia Trials: A Systematic Review of Registered Studies.

BACKGROUND: Although there are evolving techniques and technologies for treating ventricular tachycardia (VT), the current landscape of clinical trials for managing VT remains understudied. OBJECTIVE: The objective of this study was to provide a systematic characterisation of the interventional management of VT through an analysis of the ClinicalTrials.gov, clinicaltrialsregister.eu, anzctr.org.au and chictr.org.cn databases. METHODS: We queried all phase II to IV interventional trials registered up to November 2023 that enrolled patients with VT. Published, completed but unpublished, terminated, or ongoing trials were included for final analysis. RESULTS: Of the 698 registered studies, 135 were related to VT, with 123 trials included in the final analysis. Among these trials, 25 (20%) have been published, enrolling a median of 35 patients (interquartile range [IQR] 20-132) over a median of 43 months (IQR 19-62). Out of the published trials, 14 (56%) were randomised, and 12 (48%) focused on catheter ablation. Twenty-two (18%) have been completed but remain unpublished, even after a median of 36 months (IQR 15-60). Furthermore, 27 (22%) trials were terminated or withdrawn, with the most common cause being poor enrolment. Currently, 49 (40%) trials are ongoing and novel non-ablative technologies, such as radioablation and autonomic modulation, account for 35% and 8% of ongoing trials, respectively. CONCLUSIONS: Our analysis revealed that many registered trials remain unpublished or incomplete, and randomised controlled trial evidence is limited to only a few studies. Furthermore, many ongoing trials are focused on non-catheter ablation-based strategies. Therefore, larger pragmatic trials are needed to create stronger evidence in the future.

Clinical utility of oesophageal temperature monitoring in AF ablation: An updated meta-analysis and review of literature.

BACKGROUND: Atrial fibrillation (AF) ablation can lead to oesophageal thermal injuries (ETI). These are thought to be the precursor of the much rarer but frequently fatal atrio-oesophageal fistulas. Many centers performing AF ablation routinely use oesophageal temperature monitoring (ETM). This meta-analysis aims to determine the utility of ETM in preventing ETI in the context of radiofrequency catheter ablation of AF. METHODS: A systematic search of PubMed, Embase databases and Cochrane registry was performed comparing ETI between ETM and non-ETM strategies in AF ablation. Data on endoscopically determined ETI, AF recurrence, procedure time and ablation time were extracted. Statistical analyses including subgroup and covariate analyses were performed using random effect model in R platform. RESULTS: ETI were similar in both ETM (n = 864) and non- ETM groups (n = 639) (RR 1.04, 95 % CI 0.34-3.23) across 12 studies. AF recurrence was statistically similar in both groups (IRR 0.92, 95 % CI 0.73-1.17) but showed a lower trend in non-ETM group. Ablation time was numerically lower in the ETM group and procedure time was numerically higher trend in the ETM group; but they were not statistically significant. Covariate analysis found that posterior wall ablation power setting, additional linear ablation, BMI, use of GA or prophylactic PPI after ablation had no significant correlation in the incidence of ETI. CONCLUSION: ETM was not associated with a reduced incidence of ETI during AF ablation. Evidence supporting the routine use of ETM to reduce the risk of ETI or atrio-oesophageal fistulas is lacking.

Semantic segmentation in medical images through transfused convolution and transformer networks.

Recent decades have witnessed rapid development in the field of medical image segmentation. Deep learning-based fully convolution neural networks have played a significant role in the development of automated medical image segmentation models. Though immensely effective, such networks only take into account localized features and are unable to capitalize on the global context of medical image. In this paper, two deep learning based models have been proposed namely USegTransformer-P and USegTransformer-S. The proposed models capitalize upon local features and global features by amalgamating the transformer-based encoders and convolution-based encoders to segment medical images with high precision. Both the proposed models deliver promising results, performing better than the previous state of the art models in various segmentation tasks such as Brain tumor, Lung nodules, Skin lesion and Nuclei segmentation. The authors believe that the ability of USegTransformer-P and USegTransformer-S to perform segmentation with high precision could remarkably benefit medical practitioners and radiologists around the world.

Coagulation abnormalities & thromboprophylaxis in COVID-19.

The ongoing pandemic of novel coronavirus 2019 is rapidly evolving, and newer organ- and system-specific manifestations are being observed. Thrombotic complications and coagulopathy are frequent manifestations of the disease, especially in sick patients, which appear to be unique and distinct from sepsis-induced coagulopathy, disseminated intravascular coagulation and other viral infection-induced coagulation abnormalities. Elevated D-dimers and fibrinogen in the early stage of the disease with minimally deranged prothrombin time and platelet counts are prominent and distinguishing features. Venous and arterial thromboses, as opposed to bleeding events, are the major clinical correlates. There is much to be known about the pathogenesis of COVID-associated coagulopathy; however, the mechanisms overlap with thrombotic microangiopathy, haemophagocytic syndrome and antiphospholipid syndrome compounded by the diffuse endothelial damage. The recommendations regarding the treatment are still evolving, but antithrombotic therapy has a definite role in positive outcomes of sick patients.

Cardiovascular manifestations of COVID-19: An evidence-based narrative review.

The recent outbreak of coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization on March 11, 2020. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, primarily involves the respiratory system with viral pneumonia as a predominant manifestation. In addition, SARS-CoV-2 has various cardiovascular manifestations which increase morbidity and mortality in COVID-19. Patients with underlying cardiovascular diseases and conventional cardiovascular risk factors are predisposed for COVID-19 with worse prognosis. The possible mechanisms of cardiovascular injury are endothelial dysfunction, diffuse microangiopathy with thrombosis and increased angiotensin II levels. Hyperinflammation in the myocardium can result in acute coronary syndrome, myocarditis, heart failure, cardiac arrhythmias and sudden death. The high level of cardiac troponins and natriuretic peptides in the early course of COVID-19 reflects an acute myocardial injury. The complex association between COVID-19 and cardiovascular manifestations requires an in-depth understanding for appropriate management of these patients. Till the time a specific antiviral drug is available for COVID-19, treatment remains symptomatic. This review provides information on the cardiovascular risk factors and cardiovascular manifestations of COVID-19.

An interesting response to adenosine during right ventricular pacing. What is the mechanism?

We describe an interesting case in which single dose of adenosine during RV pacing elicited a series of abrupt transitions in the retrograde activation behaviour in an 11-year-old child undergoing electrophysiology study for Wolff-Parkinson-White syndrome.

InstaCovNet-19: A deep learning classification model for the detection of COVID-19 patients using Chest X-ray.

Recently, the whole world became infected by the newly discovered coronavirus (COVID-19). SARS-CoV-2, or widely known as COVID-19, has proved to be a hazardous virus severely affecting the health of people. It causes respiratory illness, especially in people who already suffer from other diseases. Limited availability of test kits as well as symptoms similar to other diseases such as pneumonia has made this disease deadly, claiming the lives of millions of people. Artificial intelligence models are found to be very successful in the diagnosis of various diseases in the biomedical field In this paper, an integrated stacked deep convolution network InstaCovNet-19 is proposed. The proposed model makes use of various pre-trained models such as ResNet101, Xception, InceptionV3, MobileNet, and NASNet to compensate for a relatively small amount of training data. The proposed model detects COVID-19 and pneumonia by identifying the abnormalities caused by such diseases in Chest X-ray images of the person infected. The proposed model achieves an accuracy of 99.08% on 3 class (COVID-19, Pneumonia, Normal) classification while achieving an accuracy of 99.53% on 2 class (COVID, NON-COVID) classification. The proposed model achieves an average recall, F1 score, and precision of 99%, 99%, and 99%, respectively on ternary classification, while achieving a 100% precision and a recall of 99% on the binary class., while achieving a 100% precision and a recall of 99% on the COVID class. InstaCovNet-19's ability to detect COVID-19 without any human intervention at an economical cost with high accuracy can benefit humankind greatly in this age of Quarantine.

Sudden unexpected improvement in the atrioventricular conduction. What is the mechanism?

The 12-lead electrocardiogram (ECG) of a 79-year-old male patient with recurrent pre-syncope showed irregular sinus rhythm with constant PR interval and left bundle branch block (LBBB) with intermittently blocked P waves. The beat following the blocked P wave had a narrower QRS with a shorter PR interval. The phenomenon of bilateral bundle branch block explains the sudden improvement in the atrioventricular conduction.

Right bundle branch block pattern after uncomplicated right ventricular outflow tract pacing in a patient with a left sided superior vena cava and corrected tetralogy of Fallot.

Usually an electrocardiogram after right ventricular (RV) pacing should yield left bundle branch block (LBBB) pattern. However, the presence of right bundle branch block (RBBB) pattern after pacemaker implantation should alert the physician to a malposition of lead. We report a case of 18-year-old female who underwent dual chamber pacemaker implantation and had RBBB pattern post implantation. Detailed evaluation revealed an uncomplicated right ventricular outflow tract pacing. The possible causes of this abnormal pattern after an uncomplicated RV pacing are also reviewed.

Correlation of pacing site in right ventricle with paced QRS complex duration.

BACKGROUND: Pacing from RV mid septum and outflow tract septum has been proposed as a more physiological site of pacing and narrower paced QRS complex duration. The paced QRS morphology and duration in different RV pacing sites is under continued discussion. Hence, this study was designed to address the correlation of pacing sites in right ventricle with paced QRS complex duration. METHODS: Two hundred fifty-two consecutive patients who underwent pacemaker implantation were enrolled. Baseline clinical characteristics were recorded for each patient. All patient underwent fluoroscopy, electrocardiogram and echocardiography post pacemaker implantation. Paced QRS duration was calculated from the leads with maximum QRS duration. RESULTS: Mean paced QRS (pQRS) duration was significantly higher in apical septum group with a mean of 148.9 ±â€¯14.8 m s compared to mid septum (139.6 ±â€¯19.9 m s; p-value 0.003) and RVOT septum (139.6 ±â€¯14.8 m s; p-value 0.002) groups, respectively. There was no significant difference between mid-septal and RVOT septal pQRS duration. On multivariate analysis, female gender, baseline QRS duration and RVOT septal pacing were the only predictors for narrow pQRS duration (<150 msec). CONCLUSION: RV mid-septal and RVOT septal pacing were associated with significantly lower pQRS duration as compared with apical pacing. Based on multivariate analysis RVOT septal pacing appears to be preferred and more physiological pacing site.

False positive retroaortic left circumflex coronary artery in a patient with atrial septal defect.

Retroaortic course of coronary artery is a relative contraindication for device closure of an atrial septal defect. In this brief report, we demonstrate, for the first time, inferior aortic recess mimicking retroaortic left circumflex coronary artery in a patient with atrial septal defect. This distinction is important to avoid spurious diagnosis of anomalous coronary artery denying patient a chance of nonsurgical closure of atrial septal defect.

Operable patent ductus arteriosus even with differential cyanosis: a case of patent ductus arteriosus and mitral stenosis.

Patients with patent ductus arteriosus and significant left-to-right shunt develop Eisenmenger syndrome at an early age and are not operable after development of irreversible pulmonary artery hypertension. Patients with mitral stenosis, however, are treatable even with suprasystemic pulmonary artery pressures. A combination of these two lesions is rare. We document a patient with differential cyanosis who improved after corrective surgery of both the lesions. The importance of post-capillary pulmonary artery hypertension in shunt lesions needs to be better appreciated.

Tilted ECG - An unusual tilt test response.

Tilt testing is a commonly used diagnostic tool to evaluate syncope of undetermined etiology. We hereby describe a twelve year old male child who developed presyncope during provocative head up tilt testing along with ST segment elevation in cardiac monitor during presyncope. Patient underwent repeat head up tilt testing along with holter monitoring which showed a left bundle branch block escape rhythm. Hence development of ST elevation was due to the improper filter application in single lead ECG monitor. This case highlights the importance of filters in electrocardiographic monitoring.