Abstract
Left atrial (LA) dimensions, wall composition and function strongly depend on left ventricular (LV) diastolic function and impaired in patients with preclinical diastolic disfunction (PDD), ...which increases the likelihood of atrial fibrillation (AF) occurrence. LA longitudinal strain (LALS) is a sensitive parameter of subclinical myocardial changes and its reduction might be predictive for AF.
Methods
168 patients (90 female) 68±9 years with arterial hypertension in sinus rhythm with preserved systolic function (LVEF>50%) and PDD and without renal or valvular disease and 45 age and sex matched healthy controls were followed up for 2 years. PDD was diagnosed at stress echocardiography (SE) if E/e' ≥13, transmittal E wave deceleration time reduction >50ms, systolic pulmonary artery pressure (sPAP) >30 mmHg, and patients remained asymptomatic. LALS was measured by speckle tracking echocardiography as average value of two basal segments in 4 chamber view along with LA end-systolic volume index (LAVi), LA EF, LV mass index (LVMi), and LVLS. 72 hours Holter monitoring was performed every 6 months.
Results
Patients with PDD had larger LAVi, less LALS, higher LVLS and bigger LVMi compared with controls (LAVi 30.5±4.9 ml/m2 vs 23.1±4.8 ml/m2, p<0.001; LALS 34.7±6.9% vs 45±4.3%, p<0.001; LVLS –17.4±2.4% vs –20.8±2.1%, p<0.002; LVMi 81.8±12.3 g/m2 vs 68±9.2 g/m2, p<0.001). AF was registered in 42 (25%) patients with PDD. LAVi, LVLS and LVMi did not significantly differ in PDD patients with or without incidents of AF however LALS was significantly less in patients with AF (26.8±7.5% vs 37.2±8.1%, p<0.01). Multivariate analysis defined LALS as an independent predictor of AF development (OR=2.4; 95% CI=2.41–5.96; p<0.01) with the cut-off value of 28.9%.
Conclusion
LA peak reservoir LS is an independent predictor of AF development in patients with PDD.
Abstract
Preclinical diastolic disfunction (PDD) often progresses to heart failure and distinct clinical predictors for this transformation are yet to be defined. Since deterioration of longitudinal ...strain (LS) can occur before the changes of more conventional parameters, we assumed that right ventricular free wall longitudinal strain (RVLS) might start deteriorating before the pulmonary hypertension can be established.
Methods
We followed up 243 patients (143 female) 67±9 years with PDD for 3 years. All patients had an impaired relaxation or pseudo normal transmitral patterns and E/e' 8–13 at rest, normal NT-proBNP values, and systolic pulmonary artery pressure (sPAP) ≤30 mm Hg. PDD was diagnosed by stress echocardiography (SE) if E/e' ≥13, transmittal E wave deceleration time reduction >50ms, systolic pulmonary artery pressure (sPAP) <30 mmHg, and patients remained asymptomatic during SE. RVLS as average of RV free wall 3 segments values, left atrial peak reservoir LS (LALS) as average of two LA basal segments in four chamber view and left ventricular peak systolic global LS (LVGLS) were measured by speckle tracking (ST). ST and SE was performed with 6 months intervals. 35 healthy subject served as controls.
Results
Patients with PDD had higher RVLS, LVGLS, and lower LALS compared with controls (RVLS –23.2±4.2% vs –27.3±5.1%, p<0.001; LVGLS –17.8±5.2% vs –21.9±2.8%, p<0.001; LALS 39.7±3.7% vs 44.1±4.9%, p<0.002). 76 (31.3%) patients developed sPAP increase >30 mmHg at rest or SE during follow up of which 34 (44.7%) had dyspnea. Patients with increased sPAP had higher RVLS and lower LALS values at baseline compared with the rest of PDD patients without significant differences in other parameters (RVLS –17.9±2.8% vs –24.8±3.6%, p<0.002; LALS 37.7±2.3% vs 41.5±3.6%, p<0.003; LVGLS –17.4±4.8% vs –18.2±5.1%, p>0.05). Both LALS and RVLS correlated with LA end diastolic volume index (LALS r=0.51, p<0.01; RVLS r=0.54, p<0.01). Additionally RVLS was an independent predictor of sPAP rise (OR=2.7; 95% CI=2.43–6.92; p<0.01).
Conclusion
RVLS is an independent predictor of sPAP increase in patients with PDD.
Long-duration γ-ray bursts (GRBs) are the most luminous sources of electromagnetic radiation known in the Universe. They arise from outflows of plasma with velocities near the speed of light that are ...ejected by newly formed neutron stars or black holes (of stellar mass) at cosmological distances
. Prompt flashes of megaelectronvolt-energy γ-rays are followed by a longer-lasting afterglow emission in a wide range of energies (from radio waves to gigaelectronvolt γ-rays), which originates from synchrotron radiation generated by energetic electrons in the accompanying shock waves
. Although emission of γ-rays at even higher (teraelectronvolt) energies by other radiation mechanisms has been theoretically predicted
, it has not been previously detected
. Here we report observations of teraelectronvolt emission from the γ-ray burst GRB 190114C. γ-rays were observed in the energy range 0.2-1 teraelectronvolt from about one minute after the burst (at more than 50 standard deviations in the first 20 minutes), revealing a distinct emission component of the afterglow with power comparable to that of the synchrotron component. The observed similarity in the radiated power and temporal behaviour of the teraelectronvolt and X-ray bands points to processes such as inverse Compton upscattering as the mechanism of the teraelectronvolt emission
. By contrast, processes such as synchrotron emission by ultrahigh-energy protons
are not favoured because of their low radiative efficiency. These results are anticipated to be a step towards a deeper understanding of the physics of GRBs and relativistic shock waves.
Abstract
Accurate surgical timing for significant primary mitral regurgitation (PMR) still remains an issue despite of several ways of left ventricular (LV) hidden disfunction detection, including ...LV global longitudinal strain (GLS). Since novel modalities such as myocardial work (MW) or area strain (AS) are currently available we assumed that they might predict surgical timing beyond known parameters.
Methods
58 patients (31 female) 63±8 years, asymptomatic and with pulmonary systolic pressure (PSP) ≤45 mmHg on exercise echo test (ET), with PMR, in sinus rhythm, with ejection fraction (EF) ≥65% and GLS <−19.5% were enrolled into the study along with 23 healthy subjects matched by age and sex and followed up for 1 year. Comprehensive echocardiography (EchoCG) was performed with offline analysis including MW and AS by one experienced specialist. GW index (GWI) was obtained from pressure-strain loops derived from speckle tracking analysis multiplied by brachial systolic blood pressure.Global constructive work (GCW) as the sum of positive work due to myocardial shortening during systole and negative work due to lengthening during isovolumic relaxation, global wasted work (GWW) aa energy loss by myocardial lengthening in systole and shortening in isovolumic relaxation, and GW efficiency (GWE) as the percentage ratio of constructive work to the sum of constructive work and wasted work were obtained by the dedicated software.
Results
13 (22%) patients with PMR became symptomatic or increase PSP >50 mmHg on ET in 1 year follow up. EF, GLS, AS and GWI did not differ between symptomatic patients and those who remained asymptomatic during follow up, however these patients had significantly lower values of GCW, and higher values of GWW (EF 68.3±6.1% vs 69.2±6.5%, p=NS; GLS –22.4±2.3% vs 23.1±3.2%, p=NS, GWI 2452±161 mmHg% vs 2479±147 mmHg%, p=NS; GCW 1875±119 mmHg% vs 2321±124 mmHg%, p<0.01; GWW 118±9 mmHg% vs 88±7 mmHg%, p<0.03; GWE 93±8% vs 96±9%, p=NS; AS −32.5±5.4% vs −34.3±6.1%, p=NS;). Patients with subsequent symptoms development had significantly lower values of GCW and higher values of GWW. Among all parameters GCW was the predictor of MR clinical course worsening (AUC 0.769).
Conclusion
MR GCW is able to predict clinical course of patients with PMR beyond known conventional parameters.
Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): City Hall resources
Abstract
Patients with advanced arterial hypertension (HPT) without heart failure often have left ventricular (LV) changes similar to hypertensive patients with heart failure with preserved ...ejection fraction (HFpEF). We assumed that cardiac mechanics may be different in both groups.
Methods
We study 58 patients (23 female) with HPT and with left ventricular concentric hypertrophy (LVH) as well as negative diastolic stress test and 52 HPT patients (29 female) with HFpEF NYHA II-III 72±5 years. All patients where in sinus rhythm. HPT and HFpEF patients has comparable degree of LV mass index (LVMI 85.3±8.6 g/m2 vs 86.2±8.9 g/m2, P=NS). Incidence of diabetes mellitus, chronic kidney disease or chronic obstructive lung disease was comparable between groups. 43 sex and age matched healthy subjects served as control (C). Comprehensive 2D/3D echocardiography (EchoCG) with offline measurements of longitudinal (LS), circumferential (CS) and radial strain (RS) global values of entire walls and 3 myocardial layers, LV twist (LVT)was performed before and after symptom limited or heart rate of 120 bpm limited diastolic stress test.
Results
HPT and HFpEF patients had significantly lower absolute values LS, CS, AS, as well as lower values of RS, and LVT compared with controls at rest and after stress test. The values of LS, RS and LVT did not significantly differ at rest in HPT patients and HFpEF patients, but HFpEF patients had lower values of global CS (GCS) due to reduction only in endocardial layer CS (ECS) (LS: 16.4±5.2% vs 16,8±5.9, p=0.07; ECS: 10.9±2,3% vs 17.3±4.1%, p<0.01; GCS: 12.8±3.5% vs 15.1±2.1%, p<0.03; RS: 29.7±10.2% vs 31.1±12.4%, p=0.06; LVT: 2.3±1.4deg vs 2.6±1.7deg, p=0.06). After diastolic stress test patients with HFpEF had significantly lower values of LVT and GCS compared with HPT patients (LVT: 1.8±0.9deg vs 3.4±1.8deg, p<0.001; GCS: 10.4±2.7% vs 17.1±3.4%, p<0.01). We also found greater relative increase (RI) in endocardial LS and LVT in patients with HPT after stress test compared with HFpEF patients, RI of other parameters did not differ between these two groups (RI ELS: 16±2.1% vs 10.5±1,7%, p<0.03; RI LVT 33.3±6,4% vs −21.7±4.1%, p<0.0001). ECS had the diagnostic value to predict HFpEF (area under curve 0.874), RI LVT was the best predictor of HFpEF symptoms (area under curve 0.912) with cut off value 22.3%.
Conclusion
ECS is reduced in HFpEF patients compared with HPT patients with the same degree of structural abnormalities on conventional EchoCG and is a predictor of HFpEF. HPT patients have more relative improvement in ELS during stress test compared with HFpEF patients. RI LVT was the best predictor of HFpEF symptoms.
Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): City Hall resources
Abstract
Heart failure with midrange ejection fraction (HFmrEF) as a relatively new category remains understudied. Some studies have shown that patients with HFmrEF more resemble to those with ...heart failure with reduced ejection fraction (HFrEF), but many patients with HFmrEF are able to improve their EF to preserved one. The transformation course is hard to predict. We assumed that novel strain parameters might predict this transformation.
Methods
73 patients with HFmrEF NYHA II-III, 62±5 years (32 female) on optimal medical therapy and 43 age and sex matched healthy controls were involved in the study. Global values of longitudinal (GLS), circumferential (GCS) and radial strain (GRS), left ventricular torsion (LVT), peak LV twist (LVTR) and untwist rates (LVUTR), and area strain (AS) were measured by 2D/3D echocardiography and analyzed offline by one experienced specialist. All measurements were done at the study onset and in 1 year follow up.
Results
Patients with HFmrEF had significantly lower absolute values of GLS, GCS, GRS, LVT, LVTR, LVUTR and AS compared with controls. In one year follow up 24 (37%) patients with HFmrEF moved into HFrEF category and 14 (19%) moved up to HFpEF and the rest of the patients remained in HFmrEF group. Patients with HFrEF had significantly lower absolute values of AS, LVT, LVTR and LVUTR compared with patients who remained in HFmrEF group and patients that moved to HFpEF category, whereas patients with HFpEF had greated absolute values of GRS, AS and LVT, and without differences in LVTR and LVUTR compared with patients with HFmrEF. (HFrEF AS: −16.31±3.21% vs −22.34±6.31%, p<0.01; LVT: 0.72±0.13°/cm vs 1.12±0.42°/cm, p<0.03; LVTR 29.31±11.23°/s vs 48.32±19.71°/s, p<0.03; LVUTR 25.33±12.41°/s vs 49.23±18.34°/s, p<0.03; HFpEF AS: −31.23±4.35% vs −23.34±6.31%, p<0.01; LVT: 1.93±0.13°/cm vs 1.12±0.42°/cm, p<0.03; LVTR 41.62±15.81°/s vs 48.32±19.72°/s, p=0.08; LVUTR 41.41±16.72°/s vs 49.22±18.31°/s, p=0.12, GRS 45.34±7.41% vs 29.42±5.81%, p<0.002). Patients with subsequent HFrEF transformation also had lower AS values at beseline (−17.31±4.21% vs −24.21±6.83%, p<0.002). AS was the only predictor of HFmEF transformation into HFrEF or HFpEF with cut off values −17.1% and −32.7% respectively, (area under the curve 0.834)
Conclusion
Patients with HFrEF move into HFrEF category more frequently than into HFpEF. AS predicts transformation of HFmEF into HFrEF or HFpEF.
Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): City Hall resources
A procedure is described which allows for the selective and non-injectional staining of the three-dimensional microvasculatory bed (MVB) in thick sections (60-140 mu m) of formalin-fixed brain tissue ...of white rats Rattus norvegicus. This histochemical method detects ATPase activity and takes place between pH 10.5 and 11.2. Calcium ion is used to capture inorganic phosphate, calcium phosphate is converted to lead phosphate, and subsequently converted to black or dark brown lead sulfide. All vessels are revealed due to a precipitate on the endothelium and smooth muscle cells of arterioles. In some vessels, red blood cells also stain. The background is transparent with no staining of neurons, nerve fibers, glial cells, or nuclei. This allows for clear identification of arterioles, venules, and capillaries, which is difficult using other methods. New observations are described including the presence of webs connecting branching parts of arterioles and constrictions along vessels. This procedure should be useful in investigations of the MVB in rat brain.
PDF
