COVID-19 and its impact on the cardiovascular system.

Objectives: The clinical impact of SARS-CoV-2 has varied across countries with varying cardiovascular manifestations. We review the cardiac presentations, in-hospital outcomes and development of cardiovascular complications in the initial cohort of SARS-CoV-2 positive patients at Imperial College Healthcare National Health Service Trust, UK.

Methods: We retrospectively analysed 498 COVID-19 positive adult admissions to our institute from 7 March to 7 April 2020.

Aortic Stenosis in Dialysis Patients.

Aortic valve stenosis occurs 10-20 years earlier in patients on dialysis compared with the general population. This is likely related to the exposure of the valve to a milieu that predisposes to calcification as well as increased shear stress across the valve. Objective assessment of stenosis severity is largely made using echocardiography though accurate interpretation requires an understanding of the potential pitfalls of the technique and the influence of cardiac output upon the gradient measured across the valve.

Cardiac survival after pre-emptive coronary angiography in transplant patients and those awaiting transplantation.

Background And Objectives: Recent interest has focused on wait listing patients without pretreating coronary artery disease to expedite transplantation. Our practice is to offer coronary revascularization before transplantation if indicated.

Design, Setting, Participants, & Measurements: Between 2006 and 2009, 657 patients (427 men, 230 women; ages, 56.

Learning on the Web. Case 3: acute chest pain.

A 49 year old Afro-Caribbean woman presents to A&E after a 30 minute episode of severe, burning central chest pain radiating to the throat. When she had the pain she felt cold and sweaty but is now symptom-free. Episodes of a similar but less severe pain had occurred daily for the previous 10 days, predominantly at rest but also when climbing the stairs at home.

Hemodialysis-induced cardiac dysfunction is associated with an acute reduction in global and segmental myocardial blood flow.

Background And Objectives: Hemodialysis is associated with hemodynamic instability, acute cardiac ischemia, and the development of regional wall motion abnormalities (RWMAs). This study used serial intradialytic H(2)(15)O positron emission tomography scanning to confirm that the development of dialysis-induced RWMAs was associated with reduction in myocardial blood flow (MBF).

Design, Setting, Participants, & Measurements: Four prevalent hemodialysis patients without angiographically significant coronary artery disease had measurements of MBF during standard hemodialysis and biofeedback dialysis.

A rapid protocol for the prevention of contrast-induced renal dysfunction: the RAPPID study.

Objectives: This study was designed to test a rapid protocol of intravenous acetylcysteine for prevention of radiocontrast-induced nephropathy (RCIN).

Background: Oral acetylcysteine (NAC) may provide better prophylaxis against RCIN than intravenous (i.v.

Effects of brief ischemia and reperfusion on the myocardium and the role of nitric oxide.

Brief myocardial ischemia/reperfusion has complex effects on the myocardium. In the short term the myocardium may be stunned with temporarily reduced contractile function, though this may also be accompanied by the modification and de novo synthesis of proteins that protect the heart against subsequent early or delayed insults. Repeated episodes of non-lethal ischemia, which are common in the clinical setting, combine all of these phenomena and may ultimately result in chronic contractile dysfunction.

Immunocytochemical evidence for inducible nitric oxide synthase and cyclooxygenase-2 expression with nitrotyrosine formation in human hibernating myocardium.

Background: Myocardial hibernation may result from repetitive episodes of transient ischaemia leading to prolonged dysfunction. Inducible nitric oxide synthase (iNOS) expression has been demonstrated in animals following brief, non-lethal ischaemia-reperfusion injury. We therefore, hypothesised that in human hibernating myocardium: 1).

Absolute quantification of myocardial blood flow with H(2)(15)O and 3-dimensional PET: an experimental validation.

Unlabelled: The purpose of this study was to assess a 3-dimensional (3D)-only PET scanner (ECAT EXACT3D) for its use in the absolute quantification of myocardial blood flow (MBF) using H(2)(15)O.

Methods: Nine large white pigs were scanned with H(2)(15)O and C(15)O before and after partially occluding the circumflex (n = 4) or the left anterior descending (n = 5) coronary artery at rest and during hyperemia induced by intravenous dipyridamole. Radioactive microspheres labeled with either (57)Co or (46)Sc were injected during each of the H(2)(15)O scans, which allowed comparison between microsphere and PET measurements of regional MBF.

Assessment of infarct size by positron emission tomography and [18F]2-fluoro-2-deoxy-D-glucose: a new absolute threshold technique.

Along with hibernating myocardium, infarct size is a critical term in the progression of left ventricular remodelling and congestive heart failure. Both infarcted and hibernating myocardium determine changes in remote non-ischaemic tissue. This study was designed to test the accuracy of a new technique to quantify infarct size using positron emission tomography (PET) with [18F]2-fluoro-2-deoxy-D-glucose (FDG).