Silent atrial fibrillation: epidemiology, diagnosis, and clinical impact.

Silent or subclinical asymptomatic atrial fibrillation (SAF) has currently gained wide interest in the epidemiologic, neurologic, and cardiovascular communities. It is well known that the electrophysiological and mechanical effects of symptomatic and silent atrial fibrillation (AF) are the same. It is probable that because "AF begets AF," progression from paroxysmal to persistent or permanent AF might be more rapid in patients with long-term unrecognized and untreated SAF, because no treatment is sought by or provided to such patients. Moreover, SAF is common and has significant clinical implications. The clinical consequences of SAF, which include emboli (silent or symptomatic), heart failure, and early mortality, are of paramount importance. Consequently, SAF should be considered in estimating the prevalence of the disease and its impact on morbidity, mortality, and quality of life. Several diagnostic methods of arrhythmia detection utilizing the surface electrocardiogram (ECG), subcutaneous ECG, or intracardiac devices have been utilized to seek meaningful arrhythmic markers of SAF. Whereas a wide range of clinical risk factors of SAF have been validated in the literature, there is an ongoing search for those arrhythmic risk factors that precisely identify and prognosticate outcome events in diverse populations at risk of SAF. Modern diagnostic modalities for the identification of SAF exist, but should be further explored, validated, and tailored to each patient needs. The scientific community should undertake the clinical challenge of identifying and treating SAF.

Silent Atrial Fibrillation: Definition, Clarification, and Unanswered Issues.

Silent or subclinical asymptomatic atrial fibrillation has currently gained wide interest in the epidemiologic, neurologic and cardiovascular communities. The association of brief episodes of paroxysmal atrial fibrillation or surrogate atrial arrhythmias which predict future clinical adverse events have been established. Nevertheless there exists a confounding array of definitions to indicate its presence without discrete indication of which populations should be examined. Moreover the term "atrial fibrillation burden" (AFB) has emerged from such studies with a plethora of descriptions to prognosticate both arrhythmic and clinical adverse events. This presentation suggests clarification of diagnostic definitions associated with silent atrial fibrillation, and a more precise description of AFB. It examines the populations across the current disease and cardiovascular invasive therapeutic spectrum that lead to both silent atrial fibrillation and AFB. It describes the diagnostic methods of arrhythmia detection utilizing the surface ECG, subcutaneous ECG or intra-cardiac devices and their relationship in seeking meaningful arrhythmic markers of silent atrial fibrillation. Whereas a wide range of clinical risk factors of silent atrial fibrillation have been validated in the literature, there is an ongoing search for those arrhythmic risk factors that precisely identify and prognosticate outcome events in diverse populations at risk of atrial fibrillation and its complications. This presentation identifies this chaos, and focuses attention on the issues to be addressed to facilitate descriptive and comparative scientific studies in the future. It is a call to action specifically to the medical arrhythmic community and its specialty societies (i.e., ISHNE, HRS, EHRA) to begin a quest to unravel the arrhythmic quagmire associated with "silent atrial fibrillation."

Robotic Rectal Cancer Resection: A Retrospective Multicenter Analysis.

BACKGROUND: Conventional laparoscopy has been applied to colorectal resections for more than 2 decades. However, laparoscopic rectal resection is technically demanding, especially when performing a tumor-specific mesorectal excision in a difficult pelvis. Robotic surgery is uniquely designed to overcome most of these technical limitations. The aim of this study was to confirm the feasibility of robotic rectal cancer surgery in a large multicenter study. METHODS: Retrospective data of 425 patients who underwent robotic tumor-specific mesorectal excision for rectal lesions at seven institutions were collected. Outcome data were analyzed for the overall cohort and were stratified according to obese versus non-obese and low versus ultra-low resection patients. RESULTS: Mean age was 60.9 years, and 57.9 % of patients were male. Overall, 51.3 % of patients underwent neoadjuvant therapy, while operative time was 240 min, mean blood loss 119 ml, and intraoperative complication rate 4.5 %. Mean number of lymph nodes was 17.4, with a positive circumferential margin rate of 0.9 %. Conversion rate to open was 5.9 %, anastomotic leak rate was 8.7 %, with a mean length of stay of 5.7 days. Operative times were significantly longer and re-admission rate higher for the obese population, with all other parameters comparable. Ultra-low resections also had longer operative times. CONCLUSION: Robotic-assisted minimally invasive surgery for the treatment of rectal cancer is safe and can be performed according to current oncologic principles. BMI seems to play a minor role in influencing outcomes. Thus, robotics might be an excellent treatment option for the challenging patient undergoing resection for rectal cancer.

The evolution of ambulatory ECG monitoring.

Ambulatory Holter electrocardiographic (ECG) monitoring has undergone continuous technological evolution since its invention and development in the 1950s era. With commercial introduction in 1963, there has been an evolution of Holter recorders from 1 channel to 12 channel recorders with increasingly smaller storage media, and there has evolved Holter analysis systems employing increasingly technologically advanced electronics providing a myriad of data displays. This evolution of smaller physical instruments with increasing technological capacity has characterized the development of electronics over the past 50 years. Currently the technology has been focused upon the conventional continuous 24 to 48 hour ambulatory ECG examination, and conventional extended ambulatory monitoring strategies for infrequent to rare arrhythmic events. However, the emergence of the Internet, Wi-Fi, cellular networks, and broad-band transmission has positioned these modalities at the doorway of the digital world. This has led to an adoption of more cost-effective strategies to these conventional methods of performing the examination. As a result, the emergence of the mobile smartphone coupled with this digital capacity is leading to the recent development of Holter smartphone applications. The potential of point-of-care applications utilizing the Holter smartphone and a vast array of new non-invasive sensors is evident in the not too distant future. The Holter smartphone is anticipated to contribute significantly in the future to the field of global health.

The history, science, and innovation of Holter technology.

Holter technology has endured for more than 40 years, and proven to be a valuable adjunctive noninvasive diagnostic technology to record the ambulatory or long-term electrocardiogram in the study of living creatures. During this span of time, many scientists, physicians, and innovators contributed to the development and evolution of Holter technology. This essay seeks to document a view of the history and evolution of the technology during that time, and concomitantly give recognition to the scientists, physicians, and engineers who contributed so greatly.

Physicians' interpretation of "class effects": a need for thoughtful re-evaluation.

The concept of pharmacologic "class effects" exists across a broad range of medical products and is particularly pervasive with regard to cardiovascular agents. Evolution of the concept over the past two decades has shown the influence of physicians' practice patterns, pharmaceutical companies, health maintenance organizations and the Food and Drug Administration (FDA). Understanding the evolution of health care, social and economic policies, acknowledging the correction of medical misconceptions and inaccurate understanding and appreciating the emergence of new medical knowledge over the past decade should modify the clinician's viewpoint of "class effects." These revelations should signal caution in extrapolating the outcome efficacy or safety of one agent to another within a pharmacologic class. The authors urge clinicians, pharmaceutical companies, health maintenance organizations and the FDA to re-examine their concept of "class effects." An appeal is made for physicians to prescribe those pharmaceutical agents with definitive evidence of mortality and morbidity efficacy and safety established by appropriately scaled randomized clinical trials.