Speeding up beta-blockade prior to coronary CT angiography: can we predict the dose of intravenous metoprolol required to achieve target heart rate in a given patient?

AIM: To evaluate the use and safety of intravenous (IV) metoprolol in a cohort of patients undergoing coronary computed tomographic angiography (CCTA) at a university hospital, and in particular, to establish if the minimum dose required to achieve the target heart rate (HR) in a given patient can be predicted from the baseline HR. MATERIALS AND METHODS: Patients undergoing CCTA at a tertiary centre between January 2015 and May 2018, with baseline HR ≥60 bpm requiring IV metoprolol, were identified retrospectively from the database. Patients with a contraindication to beta-blockade or an indication for CCTA other than coronary disease were excluded. HR at baseline and at the time of scanning were recorded, together with the total dose of IV metoprolol administered. RESULTS: Of 625 patients identified, 330 (52.8%) achieved HR ≤60 with IV metoprolol. Patients who achieved target HR had lower baseline HR. They received a lower radiation exposure due to tight prospective gating and a lower tube voltage. The lower quartile dose of metoprolol administered was 5 mg for patients with baseline HR <65 beats per minute (bpm), but 10 mg for HR 65-74 bpm, and ≥20 mg for higher HRs. There were no cases of symptomatic bradycardia/hypotension. CONCLUSION: Patients with a resting HR of ≥60 bpm can reasonably be given an initial minimum dose of 5-20 mg metoprolol IV before CCTA, with additional doses as required.

Digital chest radiography image quality assessment with dose reduction.

A retrospective study of digital chest radiography was performed to compare the image quality and dose parameters from two X-ray rooms in different areas of the same hospital using identical X-ray units but different local protocol for obtaining chest PA and lateral radiographs. Image quality of radiographs was assessed from the printed films using well established European guidelines and modified criteria. Patient entrance surface air kerma was calculated using technical data recorded for each radiograph and measured output of the X-ray unit. Effective dose and dose to radiosensitive organs was estimated using dose calculation software PCXMC. There was no statistical significant difference in the evaluated image quality using either technique, median entrance surface air kerma to the patient reduced significantly with added filtration technique and use of normal density setting. Phantom measurements indicated that an additional filtration of 0.1 mm Cu + 1 mm Al in the X-ray beam alone reduced the entrance surface air kerma by 35%.

Unusual Sequence of Events in a Case of Takotsubo Syndrome.

A 73-year-old female with multiple comorbidities including coronary artery disease was admitted for an elective PCI of a lesion detected in the RCA. On the day of the planned PCI, shortly after right femoral artery cannulation, the patient developed a sudden complete heart block requiring the administration atropine and insertion of a temporary pacemaker. Concomitantly, the patient developed acute pulmonary edema, hypotension, and hypoxia requiring intubation for mechanical ventilation. Vasopressors were administered. A coronary angiogram showed patent left and right coronary arteries, unchanged when compared to the previous angiogram. An echocardiogram performed in the cardiac catheterization lab revealed global hypokinesis of the left and right ventricles, with severe LV systolic dysfunction (EF < 20%). Following an insertion of an intra-aortic balloon pump, the patient was transferred to the CICU. A repeat echocardiogram in the CICU two hours later revealed a classical echocardiographic presentation of Takotsubo syndrome, apical hypokinesis. By the next morning the patient's hemodynamic status significantly improved, the balloon pump was removed, and vasopressors were discontinued. Another echocardiogram was performed 24 hours after the event occurred and revealed a marked improvement in LV systolic function (EF 60%), with complete resolution of apical and septal wall motion abnormalities. Three days after the event, the patient was successfully discharged and asymptomatic at two-month follow-up. This case illustrates an atypical presentation of Takotsubo syndrome that was witnessed from onset to its complete resolution during the patient's hospital stay.

Release of the recombinant proteins, human serum albumin, beta-glucuronidase, glycoprotein B from human cytomegalovirus, and green fluorescent protein, in root exudates from transgenic tobacco and their effects on microbes and enzymatic activities in soil.

We determined the release in root exudates of human serum albumin (HSA), beta-glucuronidase (GUS), glycoprotein B (gB) from human cytomegalovirus, and green fluorescent protein (GFP) from genetically modified transgenic tobacco expressing the genes for these proteins in hydroponic culture and non-sterile soil. GUS, gB, and GFP were expressed in the plant but were not released in root exudates, whereas HSA was both expressed in the plant and released in root exudates, as shown by a 66.5-kDa band on SDS-PAGE and Western blot and confirmed by ELISA. Root exudates from GUS and gB plants showed no bands that could be attributed to these proteins on SDS-PAGE, and root exudates from GFP plants showed no fluorescence. The concentration of HSA in root exudates was estimated to be 0.021 ng ml(-1), whereas that in the plant biomass was estimated to be 0.087 ng ml(-1). The concentration of HSA in soil was estimated to be 0.049 ng g(-1). No significant differences in the number of microorganisms and the activity of selected enzymes were observed between rhizosphere soil of non-modified and HSA tobacco.

Myocardial perfusion is a useful screening test for the evaluation of cardiovascular risk in patients undergoing simultaneous pancreas kidney transplantation.

Cardiovascular disease is the leading cause of death in simultaneous pancreas kidney transplantation (SPKT) patients. SPKT is increasingly being undertaken to manage patients with advanced diabetic nephropathy and type 1 diabetes mellitus. Traditionally, invasive angiography has been used as a tool to diagnose significant coronary disease and inform decision making with regard to coronary revascularization prior to transplantation. In our retrospective analysis of 167 consecutive patients who underwent SPKT in our center, we show that using myocardial perfusion scintigraphy (MPS) as the first-line screening tool is highly sensitive without exposing the patient to undue investigative procedural risks (or an unacceptably high false-negative rate) and it provides 1-year cardiovascular outcomes that are comparable with those of patients managed via the more traditional but riskier invasive route.

Role of myocardial perfusion imaging for risk stratification in suspected or known coronary artery disease.

Nuclear cardiology is an evolving specialty that has recently benefited from technological and radiopharmaceutical advances. As a result there has been an increase in the accuracy of myocardial perfusion imaging (MPI) with gated single photon emission computed tomography (SPECT) for assessing the diagnosis and prognosis of coronary artery disease. Moreover, ECG gated SPECT allows the simultaneous assessment of both myocardial perfusion and left ventricular function, which provides additional prognostic value. With increasing concern over early detection of coronary artery disease and its effective treatment, myocardial perfusion imaging is ideally placed to provide a full "one stop" functional assessment for any patient, irrespective of their exercise capacity. This applies not only to patients with chest pain but also to those with myocardial infarction, revascularisation, and heart failure, and those being assessed for non-cardiac surgery. The focus of this review is the use of myocardial perfusion imaging in risk stratification for coronary artery disease.

Allergic reactions to the polymeric glucose-based peritoneal dialysis fluid icodextrin in patients with renal failure.

A new glucoee polymer, icodextrin, related to maltose, is in increasing use as a peritoneal dialysis fluid. We report on adverse events seen in our unit during a 12-month period after the introduction of this reagent.

Synovial fluid lymphocytes differ from peripheral blood lymphocytes in patients with rheumatoid arthritis.

Peripheral blood (PBL) and synovial fluid lymphocytes (SFL) from 12 patients with rheumatoid arthritis (RA) were analyzed using monoclonal antibodies that detect specific T cell surface antigens (OKT3, OKT4, OKT8, SC1) and antigens associated with lymphocyte activation (anti-Ia, OKT10, B3/25). RA patients' PBL contained 1010 +/- 74 OKT4+ and 401 +/- 62 OKT8+ cells/mm3 (ratio OKT4+/OKT8+ = 2.4 +/- 0.3). In contrast, SFL from these patients exhibited a significantly different proportion of T cell subsets (ratio OKT4+/OKT8+ = 1.1 +/- 0.5) (p less than 0.0001) with 630 +/- 180 OKT4+ and 595 +/- 225 OKT8+ cells/mm3. Synovial fluid contained significantly more activated T cells based on the presence of Ia-positive T cells (19 +/- 5%) and reactivity with antibody OKT10 (49 +/- 7%) compared with RA-PBL (8 +/- 3% Ia-positive T cells and 13 +/- 6% OKT10+). Compared with RA-PBL, normal PBL contained an elevated number of OKT8+ cells (610 +/- 48/mm3), a similar number of OKT4+ cells (1040 +/- 86/mm3), and a lower percentage of activated lymphocytes (3 +/- 2% Ia-positive T cells and 10 +/- 8% OKT10+ cells). SFL, RA-PBL, and normal PBL all showed less than 3% cells reactive with antibody B3/25 (anti-transferrin receptor antibody), a marker found on in vitro activated T cells. These findings demonstrate that the lymphocytes at the site of inflammation differ significantly from the lymphocytes present in the peripheral blood of the same patients. RA patients had a small but significant decrease in the number of OKT8+ cells/mm3 compared with normal PBL (p less than 0.01), suggesting that this lymphocyte subset may home to synovial tissues, where it becomes activated.

Outbreak of acute hepatitis C following the use of anti-hepatitis C virus--screened intravenous immunoglobulin therapy.

BACKGROUND & AIMS: Hepatitis C virus (HCV) infection has been associated with intravenous (IV) immunoglobulin (Ig), and plasma donations used to prepare IV Ig are now screened to prevent transmission. Thirty-six patients from the United Kingdom received infusions from a batch of anti-HCV antibody-screened intravenous Ig (Gammagard; Baxter Healthcare Ltd., Thetford, Norfolk, England) that was associated with reports of acute hepatitis C outbreak in Europe. The aim of this study was to document the epidemiology of this outbreak. METHODS: Forty-six patients from the United Kingdom treated with Gammagard (34 exposed and 12 unexposed to the batch) returned epidemiological questionnaires. RESULTS: Eighty-two percent of the exposed patients (28 of 34) became positive for HCV RNA. Eighteen percent of the patients (6 of 34) who had infusions with this batch tested negative for HCV RNA, but 2 of the patients had abnormal liver function and subsequently seroconverted to anti-HCV antibody positive. Twenty-seven percent of the patients (9 of 34) developed jaundice, and 79% (27 of 34) had abnormal liver transferase levels. Virus isolates (n=21), including an isolate from the implicated batch, were genotype 1a and virtually identical by sequence analysis of the NS5 region, consistent with transmission from a single source. CONCLUSIONS: Hepatitis C infection can be transmitted by anti-HCV-screened IV Ig. Careful documentation of IV Ig batch numbers and regular biochemical monitoring is recommended for all IV Ig recipients.