Occlusion Of Anterior Descending Artery Research Articles

Effects of dexmedetomidine preconditioning on myocardial expression of high mobility group box-1 protein during myocardial ischemia/reperfusion injury in rats

Objective To investigate the effects of dexmedetomidine(Dex) preconditioning on myocardial expression of high mobility group box-1 protein (HMGB1) during ischemia/reperfusion(I/R) injury in rats. Methods Fifty-two healthy male SD rats, weighing 250-300 g, were randomly divided into 4 groups(n=13): group sham operation(group S), group I/R, group Dex+I/R(group D), group Dex+yohimbine+I/R(group D/Y). In group I/R, group D and group D/Y, myocardial I/R was produced by occlusion of left coronary anterior descending artery for 30 min followed by 120 min reperfusion. Blood samples were taken for detecting the concentration of IL-6 and TNF-α by ELISA at the end of reperfusion. The rats were then killed, and the heart was removed for measuring infarct size and area at risk using 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. Myocardial HMGB1 expressions were measured by Western blot analysis. Results Compared with group S, the levels of IL-6[(336±41) ng/L], TNF-α[(636±25) ng/L] in serum and the IS/AAR ratio were significantly increased, the expression of HMGB1 were also significantly increased in group I/R(P 0.05). Conclusions Dex preconditioning decrease the expression of HMGB1 and alleviate inflammatory response during myocardial ischemia/reperfusion injury(MI/RI) in rats, which might be a result of the α2 adrenergic receptor stimulation. Key words: Dexmedetomidine; Preconditioning; myocardial ischemia/reperfusion injury; High mobility group box-1 protein; Rat

TCTAP C-124 Recurrent Occlusion of Left Anterior Descending Artery During Intervention of Left Main Bifurcation

### Patient initials or identifier number STK ### Relevant clinical history and physical exam A 67-year-old man has experienced recurrent unstable angina pectoris (Canadian Cardiovascular Society angina class IV) in the last six months. He had a 30-year history of smoking twenty cigarettes per

TCTAP C-015 Rescue Percutaneous Coronary Intervention to Left Main Stem and Chronic Total Occlusion of Mid Left Anterior Descending Artery

TCTAP C-015 Rescue Percutaneous Coronary Intervention to Left Main Stem and Chronic Total Occlusion of Mid Left Anterior Descending Artery

TCTAP C-107 Massive Spiral Dissection of Left Main and Circumflex Artery in Antegrade Recanalization of Chronic Total Occlusion of Ostial Left Anterior Descending Artery

TCTAP C-107 Massive Spiral Dissection of Left Main and Circumflex Artery in Antegrade Recanalization of Chronic Total Occlusion of Ostial Left Anterior Descending Artery

Graft Flow Unaffected by Full Occlusion of Left Anterior Descending Artery during Coronary Artery Bypass Grafting in a Porcine Model

We investigated in a porcine model whether measuring both the flow distal to an anastomosis and the graft transit time flow (TTF) gives a more accurate picture of the true blood flow in the left anterior descending artery (LAD) than graft TTF measurement alone. We performed off-pump coronary artery bypass grafting (CABG)-left internal mammary artery (LIMA) to the LAD-on 5 Yorkshire-Landrace pigs. Snares were placed both proximal and distal to the anastomosis. Flow was measured with ultrasound and TTF. This was carried out on the LIMA and at 2 locations on the LAD. Measurements were performed at the following times: baseline, during proximal snaring, after proximal snare loosening, during distal snaring, after distal snare loosening, and during both proximal and distal snaring. During distal snaring, the TTF dropped (P = .047), and the pulsatile index (PI) increased (P = .025), while the ultrasound flow in the LAD dropped (P = .002). During proximal and distal snaring, the ultrasound flow dropped (P = .005), but the TTF value did not change significantly, compared with baseline. A high flow and a low PI were seen in the graft, both proximal and distal to the anastomosis, despite a fully occluded LAD. This result suggests that graft TTF measurement alone is not sufficient when performing CABG, and measurement of flow distal to the anastomosis is also necessary to determine the true blood flow in the LAD.

Liraglutide attenuates myocardial ischemia/reperfusion injury possibly through reducing cardiomyocytes apoptosis and oxidation in rats

To explore the effect of liraglutide on myocardial ischemia/reperfusion (I/R) injury in rats and related mechanisms. Twenty-four male SD rats were divided into sham group, I/R injury group, and liraglutide group by table of random number (n = 8 each). Myocardial I/R injury model was established by occlusion of the left anterior descending artery for 30 min followed by 2 h of reperfusion. HE stain method was used to observe cardiomyocyte status under light microscope, myocardial tissue samples were stained with TTC to measure the myocardial infarction size, protein expression of p53 and caspase-3 was analyzed by immunohistochemical technique and Western blot respectively, xanthine oxidase method was used to detect SOD activity, Thiobarbituric acid method was used to measure the concentration of MDA. Compared with the I/R group, the degree of myocardial damage of liraglutide group was significantly reduced and the myocardial infarct area was significantly lower ((44 ± 8) % vs. (62 ± 8) %, P<0.05) while protein expression of caspase-3 and p53 in liraglutide group was significantly downregulated (0.19 ± 0.03 vs. 0.24 ± 0.02 and 0.27 ± 0.03 vs. 0.39 ± 0.04, P<0.05). SOD activity was significantly increased and MDA concentration was significantly decreased (74.20 ± 11.10 vs. 44.04 ± 14.30 and 4.41 ± 1.07 vs. 8.72 ± 2.20, P<0.05) in liraglutide group compared to I/R group. Liraglutide protects myocardium against I/R injury possibly through reducing cardiomyocytes apoptosis and oxidation.

TCT-219 Higher Probability of Sucessful PCI in Patients With Chronic Total Occlusion of the Left Anterior Descending Artery (LAD-CTO) Compared to non LAD CTO PCI: A Single Center Study of 1,819 Consecutive Procedures

TCT-219 Higher Probability of Sucessful PCI in Patients With Chronic Total Occlusion of the Left Anterior Descending Artery (LAD-CTO) Compared to non LAD CTO PCI: A Single Center Study of 1,819 Consecutive Procedures

Spontaneous occlusion of the left anterior descending artery immediately following coronary angiography

Akut koroner sendromlu hastalarin koroner anjiyografisinde yuksek duzeyde trombojenik subendotel kollajen ve bolgesel olarak trombin uretimi, nadiren kontrast madde ile reaksiyona girerek, platelet aktivasyonu ve degranulasyonuna neden olabilir. Bu tip bir komplikasyon, muhtemelen olumcul olabilen ani arter tikanikliklarina yol acabilir. Bu yazida kararsiz anjina ile basvuran ve koroner anjiyografi cekiminden hemen sonra sol on inen arterin spontan tikanikligi gelisen 60 yasinda erkek bir olgu sunuldu. Anah tar soz cuk ler: Anjiyografi; koroner arter; spontan okluzyon. During coronary angiography of the patients with acute coronary syndrome, exposure of highly thrombogenic subendothelial collagen and local thrombin generation may rarely counteract with the contrast media used resulting promotion of platelet recruitment and degranulation. Final state may result in potentially fatal complications, such as abrupt occlusion of the coronary artery. In this article, a 60-year-old male case with unstable angina who had developed spontaneous occlusion of the left anterior descending artery immediately following coronary angiography.

Effects of emulsified isoflurane preconditioning on myocardial NF-κB activity during ischemia-reperfusion in rats

Objective To investigate the effects of emulsified isoflurane preconditioning on myocardial NF-kB activity during ischemia-reperfusion （I/R） in rats. Methods Forty-eight healthy male SD rats weighing 230-280 g were randomly divided into 4 groups with 12 animals in each group： sham operation group （group S）, I/R group, lipid emulsion ＋ I/R group （group L） and emulsified isoflurane ＋ I/R group （group EI）. In group I/R, EI and L, myocardial I/R was produced by occlusion of left coronary anterior descending artery （LAD） for 30 rain followed by 120 rain reperfusion. In group L, 30% lipid emulsion 4 ml·kg^-1·h^-1 was infused intravenously for 30 min before myocardial I/R. In group EI, emulsified isoflurane 4 ml·kg^-1·h^-1 was infused intravenously for 30 min followed by 15 min washout before myocardial I/R. In group S and I/R, normal saline was given instead. Blood samples were taken from femoral artery at the end of 120 min reperfusion for determination of serum cTnI and IL-6 concentrations and CK-MB activity by ELISA. The rats were then killed and the myocardial tissues were taken for determination of NF-kB activity by Western blot and observation of the ultrastructure by electron microscopy. Results The NF-tcB activity, serum cTnl and IL-6 concentrations and CK-MB activity were significantly higher in group I/R, EI and L than in group S （ P 〈 0.05 or 0.01 ）, while lower in group EI than in group I/R （ P 〈 0.05 ）. Microscopic examination showed that emulsified isoflurane significantly attenuated the histopathological changes in group EI. Conclusion Emulsified isoflurane pretreatment can attenuate myocardial I/R injury through decreasing the NF-kB activity and inhibiting inflammatory response in rats. Key words: Isoflurane ; Myocardial reperfusion injury ; NF-kappa B

Assessment of leftventricular regional myocardial function after acute occlusion of the left anteriordescending artery in rats model by two-dimensional strain echocardiography

：Objective To explore thevalue of two-dimensional strain echocardiography for quantitative assessing the change ofregional left ventricular myocardial function in rats following acute myocardialinfarction. Methods Sixty Wistar rats were randomly divided into two groups. The studygroup consisted of 50 rats with occlusion of LAD for 30-45 minutes and the sham-operatedgroup consisted of 10 rats without occlusion of LAD. Echocardiography were performedbefore operation, which was defined as baseline, and 1 week, 4 weeks and 8 weeks afteroperation. Left ventricular internal diameter at diastole ( LVIDd) and systole 0. 01). Compared with baseline andsham-operated group,LVIDd,LVIDs and LVM of study group all increased significantly ( P<0. 05) in 4 weeks and 8 weeks after operation,and FS and EF reduced significantly ( P<0. 05). Two-dimensional strain obtained in interobserver and intraobserver both showedhigh agreement. Conclusions Two-dimensional strain echocardiography can assess regionalfunction of myocardium with different perfusion in rats following acute myocardialinfarction, and provides a sensitive and reliable method to follow up the process of leftventricular remodeling after myocardial infarction.

TCT-241: Prognostic Impact of Drug Eluting Stent Supported Percutaneous Coronary Intervention for Chronic Total Occlusion of Left Anterior Descending Artery

TCT-241: Prognostic Impact of Drug Eluting Stent Supported Percutaneous Coronary Intervention for Chronic Total Occlusion of Left Anterior Descending Artery

Septic Embolic Occlusion of Left Anterior Descending Artery

Septic Embolic Occlusion of Left Anterior Descending Artery

Amrinone preconditioning in the isolated perfused rabbit heart

Background. Ischemic preconditioning (IPC) reduces infarct size in experimental preparations. IPC, however, is not without detrimental effects. We studied amrinone as a possible alternative to IPC. Methods. Isolated perfused rabbit hearts were given a 5-minute infusion of 10 μmol/L amrinone followed by a 5-minute washout (n = 6). The anterior descending artery was then occluded for 1 hour and reperfused for 1 hour. Six hearts underwent IPC, with two episodes of 5-minute global ischemia followed by 5-minute reperfusion before LAD occlusion; eight control hearts received no preconditioning. Left ventricular pressure and ischemic zone epicardial monophasic action potentials were continuously monitored. Results. IPC but not amrinone reduced peak pressure before anterior descending artery occlusion. Peak pressure fell significantly during ischemia and reperfusion in all hearts. End diastolic pressure rose significantly during reperfusion in control and IPC hearts but not in amrinone hearts. Action potentials shortened during ischemia in all hearts. They returned to preocclusion values in control hearts but lasted beyond preocclusion values in IPC and amrinone hearts. Both the incidences of ventricular fibrillation and infarct size were significantly reduced in amrinone hearts but not in IPC hearts. Conclusions. Amrinone is not only a useful inotropic agent but is also a superior preconditioning agent when compared to IPC.

Intracoronary SIN-1C during reperfusion reduces infarct size in dog.

Reperfusion of ischemic myocardium may aggravate the ischemic state of injury and thus augment infarct size (reperfusion injury). The aim of this study was to reduce infarct size by an intervention at the time of reperfusion that acts only on a reperfusion-specific pathomechanism. It was investigated whether SIN-1C, a metabolite of molsidomine, can protect against reperfusion injury in canine hearts in vivo. Ten anesthetized open chest dogs underwent 1 h of left anterior descendent artery (LAD) occlusion and were randomly assigned to receive either intracoronary SIN-1C or vehicle infusion as a placebo during the first hour of reperfusion. The infusion was adjusted to LAD flow to achieve a regional blood concentration of 5 x 10(-3) M. Infarct size was assessed by triphenyltetrazolium staining after 6 h of reperfusion. Left ventricular pressure (LVP) was similar in both groups (SIN-1C: 101 +/- 6, placebo: 89 +/- 6 mm Hg, mean +/- SEM, n = 5) at the beginning of the experiment and did not change significantly thereafter from baseline values in both groups. During SIN-1C infusion, the LAD flow was increased (SIN-1C: 195 +/- 38, control: 86 +/- 17 ml/min/100 g at 30 min of reperfusion, p < 0.05), while systemic hemodynamics remained unaltered. A reduction in infarct size (percent of area at risk) was seen in the SIN-1C group (11.4 +/- 2.8%) compared with the placebo group (24.4 +/- 3.9%, p < 0.05). Infusion of papaverin (5 x 10(-5) M) following an identical protocol caused a similar vasodilation as SIN-IC, but did not reduce infarct size in five additional dox experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Early changes in contractility and coronary blood flow in the normal areas of the ischemic porcine heart

The regional responses of normal myocardium distant from an ischemic area were studied during acute anterior descending occlusion in the open-chest chloralose-anesthetized pig. Three markers of regional response in both normal and ischemic areas were used: surface ECG electrode, a force gauge in series with left ventricular outer wall fibers, and coronary blood inflow to each region as determined by electromagnetic cuff-probes. Following brief anterior descending artery occlusion (120 sec)., a characteristic rapid decline in contractile force and evolution of TQ-ST segment changes was observed in the ischemic area. In contrast, in the distant area increases in contractil force (p less than 0.001) and coronary blood flow (p less than 0.002) occurred. These distant responses were essentially obliterated following transection and cannulation of the artery supplying this region (p less than 0.05). The findings are consistent with a reflex neurovascular mechanism operating within the intact heart. This reflex is rapidly activated in order to maintain adequate levels of cardiac performance despite sudden loss of functional myocardial mass.

Myocardial ischemia and its effect on the standard limb leads of the ECG

This experimental study was based on a series of 25 dogs. Our results indicate the amplitude of the QRS complex in the standard limb leads could be lowered by decreasing coronary blood flow. Ten revascularized dogs showed diminished voltage changes after complete occlusion of the anterior descending coronary artery. Ten normal dogs showed rapid changes that were reversible: first, a lowering of the QRS complex during constriction and, then, a change back to normal after release of the coronary arteries. Pericardial effusion was produced in 5 dogs, with a subsequent decrease of the QRS voltage. Releasing the fluid into the thorax did not keep the voltage lowered. Two of the revascularized animals with anterior descending artery occlusion were later studied during constriction and release of the circumflex coronary artery. These animals also demonstrated reversible voltage changes. Finally, one clinical case was presented to show the practical application of the concepts presented in this paper. It is our belief that the experimental results reported above can shed considerable light on many an obscure clinical cardiac picture.