Publications by authors named "Sanjiv M Narayan"

Heart rate is both an indicator and modulator of cardiovascular health. Prolonged elevation in heart rate or irregular heart rhythm can trigger the onset of cardiac dysfunction, a condition termed 'tachycardia-induced cardiomyopathy'. While large animals have historically served as the primary model for studying this condition owing to their similar resting heart rates to humans, their use is limited by cost and throughput constraints.

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Pulsed field ablation (PFA) has been developed as a largely nonthermal ablation technology with a unique biophysical profile to treat atrial fibrillation. Existing evidence has shown that PFA offers a safe and efficient atrial fibrillation ablation procedure. Among different PFA technologies, the pentaspline FARAPULSE system has been the most extensively used and investigated; however, notable variability exists in workflow, fluoroscopy time, and lesion durability.

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The emergence and rapid adoption of digital health technologies (DHT) present unprecedented opportunities to democratize and reduce disparities in health care by monitoring health and disease at the point of care in all patients. However, limited access to DHT is becoming a major obstacle to realizing these goals. Access to DHT is influenced not only by well-recognized social determinants of health, but also by digital determinants of health, such as digital literacy and the need for broad access to digital infrastructure, as well as commercial and economic factors.

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Background: Regular interaction with patients with cardiac implantable electronic devices (CIEDs) provides CIED clinic personnel with unique insights into patient-related barriers and challenges to remote monitoring (RM) implementation.

Methods: Using a global network, an international survey was administered to CIED clinic personnel. Qualitative questions gathered information on perceived challenges with patient connectivity and patient-level barriers associated with RM implementation.

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Background: The incidence of stroke is increasing in young to middle-aged adults. Assessing risk factors is important in this large population whose comorbidities may differ from older adults.

Methods: In this retrospective cohort analysis of adults aged between 20 and 50 presenting to the Stanford Healthcare system from 1 January 2000 through 31 December 2021, with no prior history of stroke or transient ischemic attack, we studied the effects of 30 risk factors on the primary endpoint of incident ischemic stroke, defined by the presence of the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes for stroke and confirmed by brain imaging.

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Aims: Reduced left atrial (LA) mechanical function associates with atrial myopathy and adverse clinical endpoints in atrial fibrillation (AF) patients; however, conventional 2D imaging modalities are limited by atrial foreshortening and sub-optimally capture 3D LA motion.

Objectives: We set out to test the hypothesis that 3D LA motion features from 4D (3D + time) retrospective gated computed tomography (RGCT) associate with AF phenotypes and predict AF recurrence in patients undergoing catheter ablation.

Methods And Results: Sixty-nine AF patients (60.

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Aims: Artificial intelligence (AI) has the potential to transform cardiac electrophysiology (EP), particularly in arrhythmia detection, procedural optimization, and patient outcome prediction. However, a standardized approach to reporting and understanding AI-related research in EP is lacking. This scientific statement aims to develop and apply a checklist for AI-related research reporting in EP to enhance transparency, reproducibility, and understandability in the field.

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Background: Periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) portends significant morbidity. studies demonstrating angiotensin-converting enzyme inhibitors (ACEis) may have an immunosuppressive effect. This study leveraged a large national registry to test if propensity-matched patients taking ACEis would have higher rates of PJI following TKA than patients taking angiotensin receptor blockers (ARBs).

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Cyber-attacks on healthcare entities and leaks of personal identifiable information (PII) are a growing threat. However, it is now possible to learn sensitive characteristics of an individual without PII, by combining advances in artificial intelligence, analytics, and online repositories. We discuss privacy threats and privacy engineering solutions, emphasizing the selection of privacy enhancing technologies for various healthcare cases.

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Reducing electrophysiological (EP) signal noise is essential for diagnosis, mapping, and ablation, yet traditional approaches are suboptimal. This study tests the hypothesis that generative artificial intelligence (AI), specifically Variational Autoencoders (VAEs), can effectively denoise these signals by forming robust internal representations of 'clean' signals. Utilizing a dataset of 5706 time series from 42 patients with ischemic cardiomyopathy at risk of cardiac sudden death, we set out to apply a β-VAE model to denoise and reconstruct intra-ventricular monophasic action potential (MAP) signals, which have verifiable morphology.

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In this call for transparency, we aim to disseminate knowledge about recent CONSORT-Surrogate and SPIRIT-Surrogate checklists. SPIRIT-Surrogate is an extension of the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) checklist, developed as a consensus document and designed as a reporting guideline for randomized controlled trial (RCT) protocols using surrogate end points as the primary end points. CONSORT-Surrogate is an extension of the Consolidated Standards of Reporting Trials (CONSORT) checklist, a consensus-driven reporting guideline for RCTs using surrogate end points as the primary end points.

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Background: It is difficult to identify patients with atrial fibrillation (AF) most likely to respond to ablation. While any arrhythmia patient may recur after acutely successful ablation, AF is unusual in that patients may have long-term arrhythmia freedom despite a lack of acute success. We hypothesized that acute and chronic AF ablation outcomes may reflect distinct physiology and used machine learning of multimodal data to identify their phenotypes.

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Cardiac wall motion abnormalities (WMA) are strong predictors of mortality, but current screening methods using Q waves from electrocardiograms (ECGs) have limited accuracy and vary across racial and ethnic groups. This study aimed to identify novel ECG features using deep learning to enhance WMA detection, referencing echocardiography as the gold standard. We collected ECG and echocardiogram data from 35,210 patients in California and labeled WMA using unstructured language parsing of echocardiographic reports.

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Article Synopsis
  • Large language models (LLMs) like ChatGPT struggle with private data interpretation, specifically electronic health records (EHRs), but prompt engineering could improve their accuracy.
  • Through systematic testing of prompt techniques on 490 EHR notes, the study found that structured prompts significantly enhanced LLM accuracy from 64.3% to 91.4%, outperforming traditional natural language processing methods.
  • The results indicate that LLMs, with proper prompt strategies, can effectively identify clinical insights from EHRs without requiring expert knowledge, suggesting potential applications in other fields for automated data analysis.
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The international Working Group of the Signal Summit is a consortium of experts in the field of cardiac electrophysiology dedicated to advancing knowledge on understanding and clinical application of signal recording and processing techniques. In 2023, the working group met in Reykjavik, Iceland, and laid the foundation for this manuscript. Atrial fibrillation (AF) is the most common arrhythmia in adults, with a rapidly increasing prevalence worldwide.

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Article Synopsis
  • Patients with dyssynchronous heart failure (DHF) experience uneven heart muscle work due to conduction problems, but cardiac resynchronization therapy (CRT) can improve this synchrony, leading to better health outcomes and quality of life.
  • Researchers used advanced computational models to analyze heart function in eight patients with heart failure and left bundle branch block (LBBB) before and after CRT, finding that the therapy enhanced overall myocardial work efficiency.
  • The study revealed that the most significant reverse remodeling—improvement of heart structure—occurred in patients who initially had the greatest disparity in regional heart work, with effective CRT linked to increased function in specific areas of the heart rather than a reduction in overall work unevenness.
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Sudden cardiac death (SCD) remains a pressing health issue, affecting hundreds of thousands each year globally. The heterogeneity among people who suffer a SCD, ranging from individuals with severe heart failure to seemingly healthy individuals, poses a significant challenge for effective risk assessment. Conventional risk stratification, which primarily relies on left ventricular ejection fraction, has resulted in only modest efficacy of implantable cardioverter-defibrillators for SCD prevention.

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Article Synopsis
  • Segmenting CT is essential for clinical practices like personalized cardiac ablation, but traditional machine learning methods often require large labeled datasets which are difficult to gather.
  • The article introduces the DOKEN algorithm, which uses domain knowledge to automatically label a small training set, enabling high-performance ML segmentation without the need for extensive data.
  • In tests, the DOKEN-enhanced nnU-Net model showed impressive segmentation results, achieving a high Dice score of 96.7% and demonstrating performance comparable to expert manual segmentation, thus validating its efficacy in real-world applications.
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Background: The declining number of electrophysiologists pursuing academic research careers could have a negative impact on innovation for patients with heart rhythm disorders in the coming decades.

Objective: The objective of this study was to explore determinants of research engagement after graduation from electrophysiology (EP) fellowship programs and to evaluate associated barriers and opportunities.

Methods: A mixed methods survey of EP fellows and early-career electrophysiologists was conducted, drawing from Heart Rhythm Society members.

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Success rates for catheter ablation of atrial fibrillation (AF), particularly persistent AF, remain suboptimal. Pulmonary vein isolation has been the cornerstone for catheter ablation of AF for over a decade. While successful for most patients, pulmonary vein isolation alone is still insufficient for a substantial minority.

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Article Synopsis
  • Geographic disparities exist in the use of remote monitoring (RM) for patients with cardiac implantable electronic devices (CIED), but reasons for this variability are not well understood.
  • An international survey of CIED clinic staff from 47 countries revealed that the average RM usage among patients was around 80%, with factors like national income and clinic type influencing RM adoption.
  • Economic and structural barriers contribute to the inconsistencies in RM utilization, suggesting a need for targeted efforts by stakeholders to enhance its usage globally.
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