Timing of Regadenoson-induced Peak Hyperemia and the Effects on Coronary Flow Reserve.

Background: Regadenoson is used to induce hyperemia in cardiac imaging, facilitating diagnosis of ischemia and assessment of coronary flow reserve (CFR). While the regadenoson package insert recommends administration of radionuclide tracer 10-20 seconds after injection, peak hyperemia has been observed at approximately 100 seconds after injection in healthy volunteers undergoing cardiovascular magnetic resonance imaging (CMR). It is unclear when peak hyperemia occurs in a patient population. Objectives: The goal of this study was to determine time to peak hyperemia after regadenoson injection in healthy volunteers and patients, and whether the recommended image timing in the package insert underestimates CFR. Methods: Healthy volunteers (n=15) and patients (n=25) underwent stress CMR, including phase-contrast imaging of the coronary sinus at rest and multiple timepoints after 0.4 mg regadenoson injection. Coronary sinus flow (ml/min) was divided by resting values to yield CFR. Smoothed, time-resolved curves for CFR were generated with pointwise 95% confidence intervals. Results: CFR between 60 and 120 seconds was significantly higher than CFR at 30 seconds after regadenoson injection (p < 0.05) as shown by non-overlapping 95% confidence intervals for both healthy volunteers (30 s, [2.8, 3.4]; 60 s, [3.8, 4.4]; 90 s, [4.1, 4.7]; 120 s, [3.6, 4.3]) and patients (30 s, [2.1, 2.5]; 60 s, [2.6, 3.1]; 90 s, [2.7, 3.2]; 120 s, [2.5, 3.1]). Conclusion: Imaging at 90 seconds following regadenoson injection is the optimal approach to capture peak hyperemia. Imaging at 30 seconds, which is more aligned with the package insert recommendation, would yield an underestimate of CFR and confound assessment of microvascular dysfunction.

Indispensable Role of Multimodality Imaging in Diagnosis and Management of Coronary Arteriovenous Fistulas.

We describe a patient with right coronary artery to coronary sinus fistula requiring surgical elimination. The decision process in managing fistulas depends on the size, site of origin, and symptoms caused by the fistula. We highlight the pivotal role of multimodality cardiovascular imaging in the diagnosis and management of coronary fistulas. (Level of Difficulty: Intermediate.).

Predictors of intubation in COVID-19 patients undergoing awake proning in the emergency department.

BACKGROUND: Awake prone positioning (PP) has been used to avoid intubations in hypoxic COVID-19 patients, but there is limited evidence regarding its efficacy. Moreover, clinicians have little information to identify patients at high risk of intubation despite awake PP. We sought to assess the intubation rate among patients treated with awake PP in our Emergency Department (ED) and identify predictors of need for intubation. METHODS: We conducted a multicenter retrospective cohort study of adult patients admitted for known or suspected COVID-19 who were treated with awake PP in the ED. We excluded patients intubated in the ED. Our primary outcome was prevalence of intubation during initial hospitalization. Other outcomes were intubation within 48 h of admission and mortality. We performed classification and regression tree analysis to identify the variables most likely to predict the need for intubation. RESULTS: We included 97 patients; 44% required intubation and 21% were intubated within 48 h of admission. Respiratory oxygenation (ROX) index and P/F (partial pressure of oxygen / fraction of inspired oxygen) ratio measured 24 h after admission were the variables most likely to predict need for intubation (area under the receiver operating characteristic curve = 0.82). CONCLUSIONS: Among COVID-19 patients treated with awake PP in the ED prior to admission, ROX index and P/F ratio, particularly 24 h after admission, may be useful tools in identifying patients at high risk of intubation.

Literature Review of COVID-19, Pulmonary and Extrapulmonary Disease.

In December 2019 novel coronavirus-Severe Acute Respiratory Syndrome-Corona Virus2 (SARS-CoV2)-originated from Wuhan, China, and spread rapidly around the world. This literature review highlights the dynamic nature of COVID-19 transmission and presentation. Analyzing 59 relevant articles up to May 1st, 2020 reflects that the main reported clinical manifestation of COVID-19 pandemic is fever and respiratory involvement. Also, current literature demonstrates a wide spectrum of different and atypical presentation(s) of COVID-19. The definite route of SARS-CoV2 transmission is respiratory droplets, however, virus nucleic acid has been detected in the stool and urine specimens as well. The severity of symptoms and outcomes of COVID-19 vary based on the patient's medical background, age, sex, and concurrent medical conditions (e.g. pregnancy). This is the first review that classifies all essential points regarding COVID-19 manifestations at a glance to improve the outcome of the patients by a better insight into diagnosis and management.

A Congenital Quadricuspid Aortic Valve Associated With Aortic and Mitral Regurgitation: Case Report and Literature Review.

Quadricuspid aortic valve (QAV) is a rare congenital cardiac anomaly that commonly becomes symptomatic in the fifth or sixth decade of life and can present as an isolated finding or in association with other congenital cardiovascular abnormalities. Previously, QAV was mainly a postmortem or intraoperative diagnosis and data was very limited on its natural history, associated complications, and long-term outcomes. In recent decades, however, there has been an increase in the reported cases of QAV, considering the advances in the diagnostic modalities such as transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and cardiac magnetic resonance (CMR). In this article, we present a case of a congenital QAV associated with aortic regurgitation as well as briefly review the QAV classification systems, treatment options, and long-term outcomes. A 48-year-old woman with a significant past medical history (PMH) of hypertension and coronary artery disease presented with shortness of breath, chest pain, and orthopnea for two to three weeks. The patient's TTE showed severe aortic regurgitation with significant compromise in cardiac output that could not be otherwise explained. Subsequently, her TEE revealed QAV as the underlying source of these findings. Although the diagnosis of QAV could be very challenging, it is crucial to be considered when evaluating a patient with inscrutable progressive aortic regurgitation. Today, as a result of technological advancement, QAV is being diagnosed more accurately and promptly. Since there are no universal guidelines defined for this cardiac anomaly, regular follow-up with these patients is imperative to monitor for early signs of valvular compromise and to treat accordingly through medical and surgical interventions.

Successful impella-assisted suction thrombectomy of right heart thrombus via the AngioVac device: Advantages, limitations, and alternatives.

An elderly man with cardiogenic shock who was found to have a thrombus burden in the right atrium was described. The thrombus was suctioned via the AngioVac device, with assistance from the Impella CP. This is the first reported case of the use of the AngioVac device in conjunction with left-sided mechanical circulatory devices.