scholarly journals Simultanious onset of post systolic thickening in endocardial and epicardial layers during ischemia

2013 ◽  
Vol 34 (suppl 1) ◽  
pp. P2046-P2046
Author(s):  
C. Zwicker ◽  
E. Altiok ◽  
M.- M. Becker ◽  
A. Schuh ◽  
M. Almalla ◽  
...  
Keyword(s):  
2008 ◽  
Vol 294 (6) ◽  
pp. H2680-H2686 ◽  
Author(s):  
Mohammad N. Jameel ◽  
Xiaohong Wang ◽  
Marcel H. J. Eijgelshoven ◽  
Abdul Mansoor ◽  
Jianyi Zhang

The heterogeneity across the left ventricular wall is characterized by higher rates of oxygen consumption, systolic thickening fraction, myocardial perfusion, and lower energetic state in the subendocardial layers (ENDO). During dobutamine stimulation-induced demand ischemia, the transmural distribution of energy demand and metabolic markers of ischemia are not known. In this study, hemodynamics, transmural high-energy phosphate (HEP), 2-deoxyglucose-6-phosphate (2-DGP) levels, and myocardial blood flow (MBF) were determined under basal conditions, during dobutamine infusion (DOB: 20 μg·kg−1·min−1 iv), and during coronary stenosis + DOB + 2-deoxyglucose (2-DG) infusion. DOB increased rate pressure products (RPP) and MBF significantly without affecting the subendocardial-to-subepicardial blood flow ratio (ENDO/EPI) or HEP levels. During coronary stenosis + DOB + 2-DG infusion, RPP, ischemic zone (IZ) MBF, and ENDO/EPI decreased significantly. The IZ ratio of creatine phosphate-to-ATP decreased significantly [2.30 ± 0.14, 2.06 ± 0.13, and 2.04 ± 0.11 to 1.77 ± 0.12, 1.70 ± 0.11, and 1.72 ± 0.12 for EPI, midmyocardial (MID), and ENDO, respectively], and 2-DGP accumulated in all layers, as evidenced by the 2-DGP/PCr (0.55 ± 0.12, 0.52 ± 0.10, and 0.37 ± 0.08 for EPI, MID, and ENDO, respectively; P < 0.05, EPI > ENDO). In the IZ the wet weight-to-dry weight ratio was significantly increased compared with the normal zone (5.9 ± 0.5 vs. 4.4 ± 0.4; P < 0.05). Thus, in the stenotic perfused bed, during dobutamine-induced high cardiac work state, despite higher blood flow, the subepicardial layers showed the greater metabolic changes characterized by a shift toward higher carbohydrate metabolism, suggesting that a homeostatic response to high-cardiac work state is characterized by more glucose utilization in energy metabolism.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
K Malliaras ◽  
E Polychronopoulou ◽  
I Poulakida ◽  
D Sagris ◽  
K Makaritsis

Abstract Background Neonatal murine hearts possess -for a brief period after birth- a robust capacity for spontaneous myocardial regeneration following cardiac injury. Whether hearts of neonatal large mammals possess similar regenerative potential is a matter of active investigation. Recently, two studies reported that 1-day-old and 2-day-old neonatal pigs exhibit a significant cardiac regenerative response post-myocardial infarction (MI), characterized by minimal cardiac fibrosis and spontaneous recovery of left ventricular (LV) function; this regenerative capacity is purportedly lost after the first two days of life. Purpose We sought to evaluate the regenerative potential of neonatal porcine hearts after MI. Methods Twenty-one neonatal farm pigs were randomly assigned to undergo MI by permanent ligation of the left anterior descending artery on postnatal day 1 (P1) or postnatal day 3 (P3). Infarcted P1 and P3 pigs were euthanized either at 1 week or at 7 weeks post-MI. Hearts explanted at 1 week post-MI underwent fluorescent immunohistochemistry for Ki67 and alpha-sarcomeric actinin to quantify myocyte cell cycle re-entry. Transthoracic echocardiography was performed at 7 weeks post-MI to quantify fractional shortening and systolic thickening of the anterior (infarcted) LV wall and the posterior (non-infarcted) LV wall. Hearts explanted at 7 weeks post-MI underwent staining with triphenyl-tetrazolium chloride and Masson's Trichrome to quantify infarct size, infarct circumference and infarct transmurality. Results Fourteen animals successfully completed the protocol. Infarct size (P1: 9.5±2.2% vs P3: 8.9±3.6% of LV, p=0.797), infarct circumference (P1: 33.8±7.1% vs P3: 29.8±10.6% of LV, p=0.566) and infarct transmurality (P1: 38.1±4.3% vs P3: 40.4±13.7% of anterior wall, p=0.764) were comparable in P1 and P3 animals at 7 weeks post-MI. LV fractional shortening (an index of global LV systolic function) was similar in P1 and P3 animals at 7 weeks post-MI (P1: 25.5±2.9% vs P3: 23.7±4.5%, p=0.662). Furthermore, systolic thickening in the anterior (infarcted) LV wall was depressed to a similar degree in P1 and P3 animals (P1: 31.8±5.3% vs P3: 32.3±8.5%, p=0.914) compared to systolic thickening in the posterior (non-infarcted) wall (P1: 72.5±9.0% vs P3: 69.0±11.4%, p=0.666) at 7 weeks post-MI. Myocyte cell cycle re-entry in the infarct border zone was increased in P1 animals compared to P3 animals (P1: 4.5±1.3 vs P3: 2.3±0.6 per field of view, p=0.045) at 1 week post-MI. Conclusions In contrast to recently-published reports, we did not observe a robust cardiac regenerative response in neonatal porcine hearts post-MI. Hearts of both 1-day-old and 3-day-old neonatal pigs exhibited substantial scarring and significant hypokinesia of the infarcted myocardium post-MI. Additional research is warranted to assess the cardiac regenerative potential of neonatal large mammals. Acknowledgement/Funding Co-financed by Greece and the European Union - European Social Fund


1996 ◽  
Vol 271 (4) ◽  
pp. H1384-H1393 ◽  
Author(s):  
Y. Ishibashi ◽  
J. Zhang ◽  
D. J. Duncker ◽  
C. Klassen ◽  
T. Pavek ◽  
...  

This study was performed to test the hypothesis that increases in myocardial oxygen consumption (MVo2) and myocardial contractile function during exercise are flow limited. Studies were performed in 15 chronically instrumented normal dogs. MVo2 and regional percent systolic wall thickening were measured during control conditions and during maximal vasodilation produced by infusion of adenosine (20-75 micrograms.kg-1.min-1) or adenosine combined with nitroglycerin (0.4 micrograms.kg-1.min-1; TNG) into the left anterior descending coronary artery during a three-stage graded treadmill exercise protocol. Adenosine and adenosine plus TNG significantly increased coronary blood flow by 298 +/- 26 and 306 +/- 24%, respectively, at rest and by 134 +/- 7 and 145 +/- 9%, respectively, during the heaviest level of exercise (each P < 0.01). Adenosine and adenosine plus TNG increased MVo2 at rest, but this was associated with a parallel increase in heart rate, so that MVo2 per beat was not significantly changed. Systolic wall thickening was also not changed by hyperperfusion during resting conditions. However, MVo2 per beat was increased by 12 +/- 4% with adenosine and by 13 +/- 5% with adenosine plus TNG during moderate exercise and by 23 +/- 5% with adenosine and by 27 +/- 4% with adenosine plus TNG during the heaviest level of exercise (each P < 0.05). Systolic thickening of the full left ventricular wall did not change during hyperperfusion, but thickening in the subepicardial layer was increased by 14 +/- 3% with adenosine and 18 +/- 3% with adenosine plus TNG during the heaviest level of exercise (each P < 0.05). There was no difference in wall thickening between adenosine and adenosine plus TNG. These findings imply that the increases in MVo2 which occur during exercise are limited by coronary blood flow.


Neurology ◽  
2019 ◽  
Vol 92 (8) ◽  
pp. e866-e878 ◽  
Author(s):  
Michael Taylor ◽  
John Jefferies ◽  
Barry Byrne ◽  
Joao Lima ◽  
Bharath Ambale-Venkatesh ◽  
...  

ObjectiveTo assess the feasibility, safety, and efficacy of intracoronary allogeneic cardiosphere-derived cells (CAP-1002) in patients with Duchenne muscular dystrophy (DMD).MethodsThe Halt Cardiomyopathy Progression (HOPE)-Duchenne trial is a phase I/II, randomized, controlled, open-label trial (NCT02485938). Patients with DMD >12 years old, with substantial myocardial fibrosis, were randomized (1:1) to usual care (control) or global intracoronary infusion of CAP-1002 (75 million cells). Participants were enrolled at 3 US medical centers between January and August 2016 and followed for 12 months. An independent Data and Safety Monitoring Board provided safety oversight. Cardiac function and structure were assessed by MRI, and analyzed by a blinded core laboratory. Skeletal muscle function was assessed by performance of the upper limb (PUL).ResultsTwenty-five eligible patients (mean age 17.8 years; 68% wheelchair-dependent) were randomized to CAP-1002 (n = 13) or control (n = 12). Incidence of treatment-emergent adverse events was similar between groups. Compared to baseline, MRI at 12 months revealed significant scar size reduction and improvement in inferior wall systolic thickening in CAP-1002 but not control patients. Mid-distal PUL improved at 12 months in 8 of 9 lower functioning CAP-1002 patients, and no controls (p = 0.007).ConclusionsIntracoronary CAP-1002 in DMD appears safe and demonstrates signals of efficacy on both cardiac and upper limb function for up to 12 months. Thus, future clinical research on CAP-1002 treatment of DMD cardiac and skeletal myopathies is warranted.Classification of evidenceThis phase I/II study provides Class II evidence that for patients with DMD, intracoronary CAP-1002 is feasible and appears safe and potentially effective.


1989 ◽  
Vol 256 (5) ◽  
pp. H1417-H1425
Author(s):  
P. N. Marino ◽  
D. A. Kass ◽  
L. C. Becker ◽  
J. A. Lima ◽  
J. L. Weiss

The effect of varying the site of acute regional ischemia on nonischemic myocardial function was examined by comparing regional thickening during 2-3 min circumflex (Circ) vs. left anterior descending (LAD) coronary artery occlusions in eight open-chest dogs. Cross-sectional midwall two-dimensional echocardiograms were obtained, and systolic thickening was measured at 16 equal-spaced points around the circumference. The distribution and extent of hypoperfusion was assessed by radiolabeled microspheres. The echo slice was subdivided into a hypoperfused region (Hypo), four adjacent nonischemic regions (ADJ1-4), and the remaining remote segments (Remote). The extent of hypoperfusion (%LV mass) was similar with both sets of occlusions (LAD, 29.4 +/- 2.8%; Circ, 26.0 +/- 4.4%; P = NS), as was endo- and epicardial flow in the nonischemic regions. Yet, even with like-sized Hypo regions, thickening of nonischemic myocardium was significantly greater during Circ than during LAD occlusions (P less than 0.001). These results are consistent with recently reported disparities of global functional impairment during LAD vs. Circ ischemia. The responses likely reflect differences in regional wall geometry, loading, and the three-dimensional distribution of coronary hypoperfusion between the two vascular territories.


1993 ◽  
Vol 264 (1) ◽  
pp. H110-H116 ◽  
Author(s):  
S. Miyazaki ◽  
Y. Goto ◽  
B. D. Guth ◽  
T. Miura ◽  
C. Indolfi ◽  
...  

Changes in regional myocardial work of the nonischemic wall and left ventricular (LV) asynchrony of the nonischemic wall during exercise-induced ischemia were examined in seven conscious dogs instrumented with a micromanometer for LV pressure measurement and sonomicrometers for control and ischemic wall thickness and LV external short and long axes. Ischemia was produced during steady-state exercise by a pneumatic constrictor on the left circumflex coronary artery. Time difference between peak thickening of control (anterior) and ischemic (posterior) walls was measured as an index of LV asynchrony. LV pressure-wall thickness loop area of both the control wall (LVP-CW loop) and ischemic wall was calculated as an index of regional myocardial external work. With ischemia during exercise, peak LV pressure decreased by 11%, and time difference of peak thickening in the two walls increased, accompanied by marked deformation of the LVP-CW loop during early relaxation, which was related to protodiastolic thickening of the ischemic wall. Thus, despite a significant increase in percent systolic thickening during exercise, loop area of control wall was not enhanced. These changes of the LVP-CW loop were confirmed by calculation of stress-strain loop areas as an additional index of regional myocardial external work but having true dimensions of work. Stress-strain loop area in the control wall during ischemic exercise showed a similar value to that during control exercise, thereby confirming lack of compensatory increase. Thus, during exercise-induced ischemia, regional myocardial external work in the normal region does not increase despite an increase in systolic wall thickening.(ABSTRACT TRUNCATED AT 250 WORDS)


1990 ◽  
Vol 15 (3) ◽  
pp. 737-747 ◽  
Author(s):  
Anne L. Taylor ◽  
Paolo Golino ◽  
Robin Eckels ◽  
Patricia Pastor ◽  
L. Maximilian Buja ◽  
...  
Keyword(s):  

Author(s):  
Yury Shevchenko ◽  
Gleb Borshev ◽  
Daniil Ulbashev ◽  
Margarita Vahromeeva ◽  
Anastasya Vahrameeva

Background. This article presents a comprehensive assessment of the perfusion-functional state of the LV myocardium after direct and indirect revascularization methods at various times after surgery to evaluate the complex relationship between myocardial viability and the method of revascularization. Methods. The study included 214 patients who underwent myocardial revascularization in various ways. Gated-SPECT was performed before the operation, as well as 1 month, 6 months, 1 year, and 2 or more years after the operation. Results. The groups of patients after CABG and CABG+YurLeon had differences in SRS indicators two years after surgery: 6.58±5.37 (after CABG) and 1,57±1,12 (CABG+YurLeon)(p<0.05).The most significant changes in systolic thickening (WT) occurred in segments with an accumulation of 26-40%: 1.8±1.14 (CABG), 0.51±0.35 (CABG+YurLeon), 2.6±1.19 (PCI); and in segments 41-50%: 1.23±1.10 (CABG), 0.14±0.11 (CABG+YurLeon), 2.1±0.8 (PCI) (p<0.05).In the long-term period after revascularization, the total percentage of LV myocardial segments with “functional-perfusion mismatch” stood at: 11.08±10.69% of segments (CABG), 1.26±1.2% (CABG+YurLeon), 18.44±8.70% (PCI) (p<0.05). Conclusions. Comprehensive diagnostics of patients before surgery, including gated-SPECT, allow medical professionals to more effectively choose the method of revascularization and predict the nearest and separated results. Coronary bypass surgery together with the YurLeon technique of indirect myocardial revascularization in patients with severe diffuse lesions of the coronary artery shows more effective results than other methods of surgically treating IHD.


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