Left Ventricular Hypertrophy Regression Following Transcatheter Aortic Replacement: A Comparison of Self-Expanding Versus Balloon-Expandable Prostheses.

There are limited reports on the impact of prosthesis-patient mismatch (PPM) on the regression of left ventricular hypertrophy (LVH) after transcatheter aortic valve replacement (TAVR). We compared the relative effects of supra-annular, self-expanding (SE) versus intra-annular, balloon-expandable (BE) prostheses on TAVR LVH regression. Regression of left ventricular mass index (LVMi) was evaluated in 168 consecutive TAVR patients, including 60 treated with SE valves (Evolut series) and 108 treated with BE valves (Sapien 3).

Stress-First Myocardial Perfusion Imaging.

Stress-first approaches to myocardial perfusion imaging provide diagnostically and prognostically accurate perfusion data equivalent to a full rest-stress study while saving time in the imaging laboratory and reducing the radiation exposure to patients and laboratory staff. Unfortunately, implementing a stress-first approach in a nuclear cardiology laboratory involves significant challenges such as the need for attenuation correction, triage of patients to an appropriate protocol, real-time review of stress images, and consideration of differential reimbursement. Despite it being best practice for both the patient and the laboratory, these impediments have kept the proportions of studies performed stress-first relatively unchanged in North America and world-wide in the last 10 years.

The safety of carotid stenosis during vasodilator pharmacologic stress testing.

Background: While thousands of patients undergo stress testing annually, the risk of exercise and pharmacologic stress in patients with carotid artery disease has not been fully defined but is of concern as patients are at risk for cerebrovascular accidents and transient ischemic attacks.

Methods: All patients with either ultrasound or CTA evaluation of their carotid arteries from over a 10 year period who underwent stress testing within 180 days without intervening carotid intervention were reviewed for any adverse events within 24 hours of their stress test. The primary end point was any cerebrovascular event or syncope while the secondary endpoints included death, myocardial infarction, urgent angiography, urgent revascularization, or exaggerated hemodynamic response (systolic BP drop > 20 mmHg or systolic BP > 180 mmHg at peak stress).

Buccal caffeine strips for reversal of adverse symptoms of vasodilator stress.

Background: Due to recurrent shortages of aminophylline, intravenous caffeine has emerged as a commonly used, safe and reliable method to treat adverse effects of vasodilator stress agents. We sought to evaluate the safety and effectiveness of buccal caffeine strips which are rapidly absorbed, inexpensive, readily available, and simplify caffeine administration.

Methods: Consecutive patients undergoing regadenoson stress SPECT MPI were assessed for the occurrence of symptoms during testing over an 11-week period at a single metropolitan hospital.

Determination of the ^{27}Al Neutron Distribution Radius from a Parity-Violating Electron Scattering Measurement.

We report the first measurement of the parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al elastic asymmetry is A_{PV}=2.16±0.

Hemiplegic migraine episode triggered by regadenoson.

SPECT and PET myocardial perfusion imaging (MPI) are widely used to evaluate patients for coronary artery disease. Regadenoson (a selective A adenosine receptor agonist) is a commonly used vasodilator agent for stress MPI because of its safety profile and ease of use. Common adverse reactions such as headache, shortness of breath, flushing, and chest and abdominal discomfort are typically mild and can be effectively reversed using methylxanthines such as aminophylline and caffeine.

Impact of Gd-153 scanning line source attenuation correction on downstream invasive testing.

Background: Attenuation correction (AC) using hardware and software solutions has been shown to increase the specificity of SPECT MPI by decreasing false positive results and improving prognostic ability. Theoretically this should reduce downstream testing and unnecessary costs. We sought to assess the consequences of the use of Gd-153 scanning line source attenuation correction during SPECT myocardial perfusion imaging (MPI) on downstream invasive testing.

Non-traditional factors affecting referral for coronary angiography following SPECT myocardial perfusion imaging.

Background: The use of myocardial perfusion imaging (MPI) in the management of coronary artery disease (CAD) is well established. Although prior studies have shown disparities in the use of invasive angiography in patients with acute MI, data on factors affecting referral to angiography post-MPI are lacking. We sought to evaluate the primary determinants of referral to invasive angiography post-MPI and specifically assess the role of non-traditional non-clinical factors such as race/ethnicity, socioeconomic factors, insurance status, and marital status.

Precision Measurement of the Beam-Normal Single-Spin Asymmetry in Forward-Angle Elastic Electron-Proton Scattering.

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of θ_{lab}=7.9° and a mean energy of 1.

Tablet-Based Limited Echocardiography to Reduce Sonographer Scan and Decontamination Time during the COVID-19 Pandemic.

Background: Limited assessments with handheld ultrasound have found meaningful clinical use in the care of acutely ill patients. However, there are limited data on incorporating handheld-based limited echocardiography into the echocardiography laboratory. The purpose of this study was to assess the efficacy of limited handheld tablet echocardiography as an alternative to traditional echocardiography during the coronavirus disease 2019 (COVID-19) pandemic as a means to limit exposure while providing essential clinical information.

Comparison of Benefit of Transcatheter Aortic Valve Implantation in Patients With Low Gradient Versus High Gradient Aortic Stenosis and Left Ventricular Dysfunction.

Patients with low gradient severe aortic stenosis (LG-AS) often exhibit significant limitations in functional status and quality of life. We aimed to evaluate the clinical effect of transcatheter aortic valve implantation (TAVI) on LG-AS patients compared to those with high transvalvular gradients and similar left ventricular dysfunction. Retrospective analysis of records for all patients with a left ventricular ejection fraction <50% who underwent TAVI at our institution was performed.

Efficiency of tetrofosmin versus sestamibi achieved through shorter injection-to-imaging times: A systematic review of the literature.

Based on superior image quality, more accurate gated images, and lower radiation exposure to patients, Technetium-99m (Tc-99m) based tracers are preferred over Thallium-201 for SPECT myocardial perfusion imaging. The two Tc-99m tracers, sestamibi and tetrofosmin, have many similar characteristics but there are differences in blood and liver clearance rates, as well as the recommended time after injection for imaging to achieve optimal image quality. Because published peer-reviewed studies examining optimal times between injection and imaging are limited, it can be difficult to identify evidence-based opportunities to optimize imaging protocols.

Clinical predictors of antitachycardia pacing response in implantable cardioverter defibrillator patients.

Background: Antitachycardia pacing (ATP) provides safe and painless termination of reentrant ventricular arrhythmias in patients with implantable cardioverter defibrillator (ICDs), improving their quality of life. Established predictors of ATP responsiveness are not well known; only longer ventricular tachycardia (VT) cycle length and higher ejection fraction have been found to predict ATP success.

Objective: To investigate clinical and ECG predictors of ATP response in ICD patients with monomorphic VT.

Clinical effectiveness of an outpatient pathway for low-risk chest pain emergency department visits.

Background: Studies suggest that patients who present with atypical chest pain and are low or low-intermediate risk can safely undergo a rapid rule-out for cardiac ischemia with serial ECGs and cardiac biomarkers followed by additional testing as needed. We sought to evaluate a novel Emergency Department (ED) protocol for patients to undergo their additional functional testing as an outpatient.

Methods: Patients presenting to the ED with atypical chest pain, normal ECG, and negative cardiac troponin felt to be low risk were referred for outpatient stress testing within 72 hours of presentation as part of a pilot program.

Correction to: Risk stratification with vasodilator stress SPECT myocardial perfusion imaging in patients with elevated cardiac biomarkers.

The following error (highlighted in bold below) appears in the Results section of the Abstract: A total of 503 patients were followed for an average of 33.6 ± 16.2 months, with a mean age of 69.

Risk stratification with vasodilator stress SPECT myocardial perfusion imaging in patients with elevated cardiac biomarkers.

Background: Although the diagnostic accuracy and prognostic utility of vasodilator stress MPI have been well established in the non-acute setting, the efficacy of all of the vasodilator stressors in risk stratifying post-MI patients as well as the evaluation of cardiac troponin elevation of unclear etiology is not established. Accordingly, the aim of the present study was to investigate the prognostic efficacy of vasodilator stress MPI in the setting of elevated cardiac troponin to accurately risk stratify these higher-risk patients.

Methods: All patients from two tertiary centers, from 1/1/2010 through 12/31/2012, with elevated cardiac biomarkers within < 7 days and undergoing stress SPECT MPI testing were studied.