Comparison of gross pathology inspection and 9.4 T magnetic resonance imaging in the evaluation of radiofrequency ablation lesions in the left ventricle of the swine heart.

Aims: Gross pathology inspection (patho) is the gold standard for the morphological evaluation of focal myocardial pathology. Examination with 9.4 T magnetic resonance imaging (MRI) is a new method for very accurate display of myocardial pathology. The aim of this study was to demonstrate that lesions can be measured on high-resolution MRI images with the same accuracy as on pathological sections and compare these two methods for the evaluation of radiofrequency (RF) ablation lesion dimensions in swine heart tissue during animal experiment. Methods: Ten pigs underwent radiofrequency ablations in the left ventricle during animal experiment. After animal euthanasia, hearts were explanted, flushed with ice-cold cardioplegic solution to relax the whole myocardium, fixed in 10% formaldehyde and scanned with a 9.4 T magnetic resonance system. Anatomical images were processed using ImageJ software. Subsequently, the hearts were sliced, slices were photographed and measured in ImageJ software. Different dimensions and volumes were compared. Results: The results of both methods were statistically compared. Depth by MRI was 8.771 ± 2.595 mm and by patho 9.008 ± 2.823 mm; p = 0.198. Width was 10.802 ± 2.724 mm by MRI and 11.125 ± 2.801 mm by patho; p = 0.049. Estuary was 2.006 ± 0.867 mm by MRI and 2.001 ± 0.872 mm by patho; p = 0.953. The depth at the maximum diameter was 4.734 ± 1.532 mm on MRI and 4.783 ± 1.648 mm from the patho; p = 0.858. The volumes of the lesions calculated using a formula were 315.973 ± 257.673 mm3 for MRI and 355.726 ± 255.860 mm3 for patho; p = 0.104. Volume directly measured from MRI with the "point-by-point" method was 671.702 ± 362.299 mm3. Conclusion: Measurements obtained from gross pathology inspection and MRI are fully comparable. The advantage of MRI is that it is a non-destructive method enabling repeated measurements in all possible anatomical projections.

Levels of endothelial substances in patients with newly identified hypertension compared with healthy controls.

INTRODUCTION: Endothelial dysfunction occurs at the very beginning of hypertension. The primary goal of our study was to determine plasmatic levels of multiple endothelial substances in otherwise healthy patients with primary hypertension and compare them to healthy individuals. Secondary goals were to determine the change in NOx levels after initiation of treatment and to compare the NOx levels in patients with established resistant hypertension. MATERIALS AND METHODS: 87 consecutive patients were enrolled. In the exploratory cohort of 22 healthy and 28 hypertensive individuals, plasmatic levels of big endotelin-1, asymmetric dimethylarginin, osteopontin, oxidized LDL, 3-nitro-L-tyrosine, growth/differentiation factor 15, intercellular adhesion molecule, vascular cell adhesion molecule, tumor necrosis factor-α, vascular endothelial growth factor, interleukins -1ß, -6 and nitric oxide levels (NO, expressed as NOx) were determined. The remaining 27 individuals were used as a validation cohort. Ten patients with established resistant hypertension were enrolled from our Hypertension Clinic. RESULTS: There was a statistically significant difference in NOx levels between healthy controls and hypertensive patients/resistant hypertensive patients: 45.164 µmol/L ± 48.627 vs 17.763 µmol/L ± 10.333 (P=0.00004)/14.36 µmol/L ± 7.194 (P=0.00007). CONCLUSION: We identified a decrease in total NOx plasmatic levels in otherwise healthy patients with primary hypertension that was more profound in patients with resistant hypertension. Plasmatic levels of other determined endothelial substances did not differ among the groups. However, due to the significant variability of plasmatic NOx levels even in healthy controls and many factors that affect it, we cannot recommend it to be used to assess endothelial function routinely.

The Effect of Mindfulness-Based Stress Reduction (MBSR) on Depression, Cognition, and Immunity in Mild Cognitive Impairment: A Pilot Feasibility Study.

BACKGROUND: Mindfulness-based programs have shown a promising effect on several health factors associated with increased risk of dementia and the conversion from mild cognitive impairment (MCI) to dementia such as depression, stress, cognitive decline, immune system and brain structural and functional changes. Studies on mindfulness in MCI subjects are sparse and frequently lack control intervention groups. OBJECTIVE: To determine the feasibility and the effect of mindfulness-based stress reduction (MBSR) practice on depression, cognition and immunity in MCI compared to cognitive training. METHODS: Twenty-eight MCI subjects were randomly assigned to two groups. MBSR group underwent 8-week MBSR program. Control group underwent 8-week cognitive training. Their cognitive and immunological profiles and level of depressive symptoms were examined at baseline, after each 8-week intervention (visit 2, V2) and six months after each intervention (visit 3, V3). MBSR participants completed feasibility questionnaire at V2. RESULTS: Twenty MCI patients completed the study (MBSR group n=12, control group n=8). MBSR group showed significant reduction in depressive symptoms at both V2 (p=0.03) and V3 (p=0.0461) compared to the baseline. There was a minimal effect on cognition - a group comparison analysis showed better psychomotor speed in the MBSR group compared to the control group at V2 (p=0.0493) but not at V3. There was a detectable change in immunological profiles in both groups, more pronounced in the MBSR group. Participants checked only positive/neutral answers concerning the attractivity/length of MBSR intervention. More severe cognitive decline (PVLT≤36) was associated with the lower adherence to home practice. CONCLUSION: MBSR is well-accepted potentially promising intervention with positive effect on cognition, depressive symptoms and immunological profile.