Search

Various techniques have been used in attempts to reduce interfering gastrointestinal activity in myocardial perfusion imaging (MPI); however, these approaches have yielded inconsistent results. The goal of this study was to investigate the efficacy of monitored walking, a previously unexplored technique, in reducing subdiaphragmatic activity-related artifacts during pharmacologic stress 99m Tc-tetrofosmin MPI with SPECT to improve the overall image quality. Methods: The study included patients who underwent MPI with pharmacologic stress. They were given a step counter immediately after the radiotracer injection and were randomized into a group A, with a request to walk at least 1,000 steps before imaging, and a group B, with no specific instructions about walking. The reconstructed SPECT images were assessed visually. Moderate and severe levels of subdiaphragmatic tracer activity were considered relevant for the interpretation of the scans. Additionally, myocardial and abdominal activity was semiquantitatively assessed on raw planar images, and the mean myocardium-to-abdomen count ratios were calculated. Results: We enrolled 199 patients (95 patients in group A and 104 patients in group B). Clinical characteristics did not differ significantly between the 2 groups. Patients in group A walked more steps than patients in group B ( P < 0.001), but there were no differences in the proportion of accepted scans between the 2 groups ( P = 0.41). Additionally, there were no differences in the proportion of relevant subdiaphragmatic activity between the groups ( P = 0.91). The number of steps did not impact the acceptance rate ( P = 0.29). Conclusion: A higher number of steps walked during the waiting period between pharmacologic stress and acquisition does not affect subdiaphragmatic activity-related artifacts or the proportion of accepted scans after pharmacologic stress. However, pedometer use and clear instructions motivate patients to walk while awaiting imaging. Larger studies are required to compare a higher-step-count group with a sedentary control group to assess the influence of walking on gastrointestinal artifacts in MPI., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Background: Myocardial perfusion imaging (MPI) with single photon emission computed tomography is an established non-invasive technique for assessing myocardial ischemia. This method involves the intravenous administration of a radiopharmaceutical that accumulates in the heart muscle proportional to regional blood flow. However, image quality and diagnostic accuracy can be compromised by various technical and patient-related factors, including high non-specific radiopharmaceutical uptake in abdominal organs such as the stomach, intestines, liver, and gall-bladder, leading to subdiaphragmatic artifacts. These artifacts are particularly problematic for evaluating inferior wall perfusion and often necessitate repeated imaging, which decreases gamma camera availability and prolongs imaging times., Conclusions: Despite numerous investigated techniques to reduce interfering gastrointestinal activity, results have been inconsistent, and current MPI guidelines provide scant information on effective procedures to mitigate this issue. Based on our experience, some possible approaches to reducing artifacts include choosing stress testing with an exercise stress test, when possible, late imaging, fluid intake, and consuming carbonated water immediately before imaging., (© 2024 Anja Strok et al., published by Sciendo.)

Background: The exact interaction of factors leading to myocardial dysfunction and fibrosis of the systemic right ventricle (SRV) is not completely understood. Myocardial ischemia and injury associated with a supply-demand mismatch of the pressure overloaded SRV are thought to play an important role, however studies confirming this are lacking., Methods: Adult SRV patients were included in this single centre cohort study. All patients underwent a comprehensive diagnostic and imaging workup. A two-day stress-rest SPECT was performed to assess myocardial perfusion. SRV ischemia was defined as decreased segmental tracer uptake during exercise with significant improvement at rest. Contrast enhanced cardiac magnetic resonance imaging (CMR) was also performed in a subgroup of patients without contraindication, to assess focal myocardial fibrosis. Differences between patients with and without SRV ischemia were assessed., Results: Twenty-three SRV patients (15 with transposition of the great arteries after atrial switch procedure and 8 with congenitally corrected transposition of the great arteries; 5 (22%) females; mean age 38 ± 11 years) were included. Seven (30%) patients had SRV ischemia on SPECT. Late gadolinium enhancement on CMR was more common in patients with SRV ischemia (p = 0.002). However, there was no association between SRV ischemia and different echocardiographic or CMR parameters of SRV systolic function, laboratory markers (high-sensitivity troponin I and NT-proBNP) and exercise capacity., Conclusions: Our multimodality study showed that SRV ischemia in adult SRV patients was associated with more focal myocardial fibrosis, but not with functional or imaging markers of SRV function., Competing Interests: Declaration of Competing Interest The authors report no relationships that could be construed as a conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Aims: Non-compaction cardiomyopathy (NCM) is a congenital heart disease characterized by an arrest of the myocardial compaction process. Although NCM patients have impaired formation of microvasculature, the functional impact of these changes remains undefined. We sought to analyse a potential correlation between myocardial ischemia and heart failure severity in NCM patients., Methods and Results: We enrolled 41 NCM patients (28 male and 13 female), aged 21-70 years. In all patients, we have determined left ventricular end-diastolic volume (LVEDV), left ventricular ejection fraction (LVEF), and global longitudinal strain (GLS) by echocardiography. At the same time, serum levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) have been measured, and myocardial single-photon emission computed tomography at rest and on stress was used to define significant myocardial ischemia defined as summed difference score ≥ 2. Myocardial ischemia has been demonstrated in 11 patients (27%, Group A), and 30 patients showed no significant ischemic changes (73%, Group B). The groups did not differ in sex, age, kidney, or liver function. When compared with Group B, Group A had significantly lower LVEF (35 ± 15% in Group A vs. 53 ± 11% in Group B, P < 0.001), higher LVEDV (188 ± 52 mL vs. 136 ± 52 mL, P = 0.007), lower GLS (-9.9 ± 5.2% vs. -14.5 ± 4.1%, P = 0.001), and higher NT-proBNP levels (1691 ± 1883 pg/mL vs. 422 ± 877 pg/mL, P = 0.006). Overall, higher summed difference score was associated with lower LVEF (r = -0.48, P = 0.001), higher LVEDV (r = 0.39, P = 0.012), lower GLS (r = 0.352, P = 0.024), and higher levels of NT-proBNP (r = 0.66, P < 0.001)., Conclusions: The presence of myocardial ischemia in patients with NCM is associated with worse left ventricular function, dilation of the left ventricle, and more pronounced neurohumoral activation., (© 2020 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Introduction: Pulmonary embolism (PE) is common in patients with deep venous thrombosis (DVT). The outcome of DVT with concomitant symptomatic PE is worse than the outcome of isolated DVT. The risk factors for DVT and simultaneous asymptomatic PE have not been systematically studied yet., Aim: To evaluate the frequency and risk factors for asymptomatic PE in patients with DVT., Patients/methods: In 155 consecutive patients with a first episode of DVT and no PE symptoms, a ventilation-perfusion lung scan was performed. Body mass index (BMI) and waist-to-hip ratio (WHR) were calculated and concentrations of D-dimer, high-sensitivity CRP (hsCRP), tissue plasminogen activator (t-PA) and troponin were measured. Laboratory tests for thrombophilia were performed., Results: Asymptomatic PE was present in 36% of patients. No differences in gender, age, BMI and WHR were found between the patients with and without PE. PE was more common in patients with proximal DVT than in those with distal DVT (42% vs. 17%, p<0.01), and in patients with unprovoked DVT compared to patients with provoked DVT (51% vs. 28%, p<0.01). The risk of silent PE was the highest in patients with unprovoked proximal DVT (OR, 6.9; 95% CI, 2.3-21.0). Patients with asymptomatic PE had significantly higher values of D-dimer, hsCRP, t-PA and troponin than patients with isolated DVT., Conclusions: Asymptomatic PE affected more than one third of patients with a first DVT. Unprovoked proximal DVT is the most important risk factor for the occurrence of silent PE., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Objectives: The study evaluated the systemic inflammatory response and endothelium-dependent and independent function of the brachial artery (BA) in systemic lupus erythematosus (SLE) patients with and without antiphospholipid syndrome (APS)., Methods: The study group consisted of 42 women with SLE (21 without APS; mean age 36.1 ± 9.1, and 21 with APS; mean age 43.9 ± 13.1) and 22 healthy controls (mean age 43.5 ± 10.3). Endothelium-dependent functional response was evacuate using the flow-mediated vasodilatation (FMD) of brachial artery and endothelium-independent vasodilatation by application of glyceryl trinitrate (GTN). Using biochemical methods, circulating inflammatory markers were determined., Results: In comparison to controls, in both groups of patients endothelium-dependent dilation of BA was significantly reduced, and there were no differences in FMD between patients with or without APS: SLE - 7.7% (11.9-12.1), SLE+APS 7.8% (2.4-12.8), controls - 14.6% (11.2-21.1), p<0.001. However, endothelium-independent dilation of the brachial artery was significantly lower in SLE-APS patients than in controls and also lower than in the SLE group: SLE - 24.3% (15.0-28.6), SLE+APS-17.4% (13.1-22.6), controls - 23.0% (17.8-30.1), p=0.015 vs. p=0.027. Patients with SLE had significantly higher values of VCAM-1, hs-CRP, and fibrinogen than controls. In patients with SLE+APS, an additional significant increase of inflammatory markers was registered., Conclusions: The results of our study indicate that patients with SLE have deteriorated endothelium-dependent and those with APS also independent vascular function which could be, together with increased inflammatory response, involved in vascular complications in these patients. The presence of APS aggravates systemic inflammatory response.

Aim: Determination of the functional capability of the peripheral arteries is increasingly used as an early marker of vessel disease. The aim of this study was to evaluate flow-mediated (FMD) and glyceryl trinitrate-mediated (NMD) dilation of the brachial artery in patients with idiopathic venous thrombosis (VT)., Methods: Flow-mediated brachial artery dilatation and the dilatation response to glyceryl trinitrate were measured using high-resolution ultrasound in 97 subjects (49 eligible patients of both sexes, mean age 51.5 ± 14.6 years, with idiopathic venous thrombosis, and 48 age-matched healthy controls)., Results: Compared to the control group, FMD was significantly reduced in the group of patients with idiopathic venous thrombosis -4.9% (95% CI 1.1-8.7%) vs. 12.7% (95% CI 7.8-17.6%), p<0.001. Patients also had diminished NMD of the brachial artery -12.5% (95% CI 6.6-18.4%) vs. 18.5% (95% CI 10.1-26.9%), p<0.001. In patients, significantly higher levels of circulatory markers (P-selectin, von Willebrand factor) of endothelial dysfunction were registered., Conclusions: Idiopathic venous thrombosis is associated with impaired flow- and GTN-mediated vasodilatory response of the brachial artery. This may suggest involvement of the functional deterioration of the vessel wall in the pathogenesis of idiopathic VT and indicate a relationship between VT and atherothrombosis.

Introduction: The aim of this study was to evaluate endothelial function in patients with primary antiphospholipid syndrome (PAPS)., Patients and Methods: Flow mediated (FMD) and glyceryl trinitrate (GTN) induced dilation of the right brachial artery were studied in 25 patients with PAPS and 25 controls matched by age, sex and conventional risk factors for atherosclerosis. Fibrinogen, D-dimer, adhesion molecules, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) antigens and activities were measured., Results: Mean (SD) FMD was significantly lower in PAPS than in controls (8+/-5% vs. 15+/-6%, P<0.001); GTN-induced dilation did not differ between the groups. There was a correlation between the baseline diameter of the brachial artery and duration of the disease (-0.56, P<0.05) and between GTN induced dilation and duration of the disease (0.51, P<0.05). Concentrations of vascular cell adhesion molecule-1 (P<0.001), intracellular adhesion molecule-1 (P<0.001) and fibrinogen (P<0.05) were higher in patients than in controls but no differences were observed for D-dimer, t-PA and PAI-1 antigens and activities. There was correlation between concentration of vascular cell adhesion molecule-1 and FMD (-0.35, P<0.05) and between intracellular adhesion molecule-1 and FMD (-0.41, P<0.05)., Conclusions: This study shows that endothelial function is impaired in patients with primary APS, possibly contributing to accelerated atherosclerosis and thromboembolic complications in these patients.

Objective: to identify whether monitoring transcutaneous oxygen pressure (TcpO(2)) can provide an objective method of assessing the results of PTA., Materials and Methods: fifty-seven patients (39 Fontaine stage II, <18 stage III or IV) had ABI, TcpO(2) at rest (stages III and IV) or during exercise (stage II) and total work capacity of the leg (stage II) measured before, 24-48 h, 2 and 6 weeks after PTA., Results: a significant increase of ABI in both groups of patients was detected immediately after successful PTA. TcpO(2) measured on the foot at rest increased in stages III and IV patients immediately after PTA (from 14 (IQR)18 to 25 (IQR)32 mmHg,p <0.05) and again after 6 weeks in comparison to follow up two (from 25 (IQR)32 to 35 (IQR)21 mmHg,p <0.05). In patients in stage II TcpO(2) decreased in a typical fashion during exercise. Total oxygen drop was most evident before treatment (352 (IQR)458 smmHg) and decreased significantly immediately after PTA (148 (IQR)175 smmHg, p<0.001)., Conclusions: TcpO(2) measurement is an useful method for investigating the success of PTA. While the macrocirculation improves immediately after successful recanalisation, complete normalisation of the microcirculation may take some weeks, especially stages III and IV disease.