Branch Of Left Coronary Artery Research Articles

Comparison of effects of oxycodone and morphine on myocardial ischemia-reperfusion injury in rats

Objective To compare the effects of oxycodone and morphine on myocardial ischemia-reperfusion (I/R) injury in rats. Methods Forty-eight SPF healthy adult male Sprague-Dawley rats, aged 8-10 weeks, weighing 250-300 g, were randomized into 4 groups (n=12 each) using a random number table: sham operation group (S group), myocardial I/R injury group (I/R group), morphine group (M group) and oxycodone group (O group). Myocardial I/R was produced by occlusion of the anterior descending branch of the left coronary artery for 30 min followed by 120 min of reperfusion.In group S, the anterior descending branch of the left coronary artery was only exposed but not ligated.In M and O groups, morphine 1.5 mg/kg and oxycodone 0.5 mg/kg were injected, respectively, via the internal jugular vein at 5 min before ischemia.At the end of reperfusion, arterial blood samples were collected via cardiac puncture for determination of the serum creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) concentrations.Myocardial infarct size was measured by 2, 3, 5-triphenyltetrazolium chloride staining.Apoptosis in cardiomyocytes was determined by TUNEL, and apoptosis index (AI) was calculated. Results Compared with S group, serum CK-MB and cTnI concentrations and AI were significantly increased, and myocardial infarct size was enlarged in I/R, M and O groups (P<0.05). Compared with I/R group, serum CK-MB and cTnI concentrations and AI were significantly decreased, and myocardial infarct size was decreased in M and O groups (P<0.05). Serum CK-MB and cTnI concentrations and AI were significantly lower, and myocardial infarct size was smaller in O group than in M group (P<0.05). Conclusion Oxycodone produces better efficacy than morphine in reducing myocardial I/R injury in rats. Key words: Oxycodone; Morphine; Myocardial reperfusion injury

Conquest of Ventricular Tachycardia: Insights Into Mechanisms, Innovations in Management: Contribution of Mark E. Josephson, MD, to Clinical Electrophysiology.

### Mohammad Shenasa, MD Cardiac mapping has always been an integral part of basic and clinical electrophysiology. Indeed, direct cardiac mapping with recording of local electrograms has been used since the early 19th century, well before intracardiac catheter mapping.1,2 Walter H. Gaskell measured cardiac contraction to investigate the sequence of cardiac activation.1 Thomas Lewis used direct electrogram mapping in a dog model with atrial and ventricular arrhythmias (Figure 1).2 Intraoperative direct epicardial and endocardial mapping was later reported in patients with preexcitation syndromes and conduction disturbances, initially by the Amsterdam group3; however, systematic use of endocardial and epicardial mapping for ventricular tachycardia (VT) was pioneered by Josephson and colleagues at the University of Pennsylvania, although epicardial mapping was reported earlier by Fontaine et al.4–8 These reports greatly improved our understanding of pathophysiology and mechanisms of VT initially in patients with coronary artery disease and previous myocardial infarction. Intraoperative endocardial mapping revealed that reentry circuits were often localized on the endocardial surface or subendocardially and that resection of those regions eliminated the substrate of VT.9,10 These intraoperative studies led directly to the techniques we use in catheter ablation of VT today and has been applied to other VT substrates. Figure 1. Thomas Lewis’s activation map for direct electrogram recording in a dog heart.2 DBL indicates descending branch of left (coronary artery); DBR, descending branch of right (coronary artery); IVC, inferior vena cava; LA, left atrium; LV, left ventricle; PA, pulmonary artery; RA, right atrium; and SVC, superior vena cava. In modern interventional electrophysiology, cardiac mapping and imaging are integrated, and this merging is critical for success in complex ablation procedures. However, electrogram mapping remains an essential part of physiological understanding of the mechanism(s) of VT. The Penn group has set standards for …

Role of miR-24, Furin, and Transforming Growth Factor-β1 Signal Pathway in Fibrosis After Cardiac Infarction.

BackgroundCardiac fibrosis after primary infarction is a type of pathological phenomena as shown by increased collagen in myocardial cells. Transforming growth factor (TGF)-β1 is a critical factor participating in myocardial fibrosis. A previous study has shown the inhibitory role on TGF-β1 by microRNA-24 (miR-24) via targeting Furin. This study thus investigated the role of miR-24 and Furin/TGF-β1 in rat myocardial fibrosis.Material/MethodsA total of 40 adult SD rats (both males and females) were prepared for myocardial infarction model by ligating the descending branch of left coronary artery after anesthesia. HE staining was performed to observe myocardial fibrosis after 1, 2, and 4 weeks. Tissue RNA was extracted to detect mRNA levels of Furin, TGF-β1, and miR-24 by real-time PCR. Western blotting was used to quantify protein expression of Furin and TGF-β1 in myocardial tissues.ResultsIncreased connective tissues were observed in myocardial tissues at 4 weeks after infarction by HE staining, which also revealed widening of the intra-myocardial cleft, along with more inflammatory cells and fibroblast hypertrophy. miR-24 expression was significantly depressed at 2 and 4 weeks after cardiac infarction (p<0.05). mRNA levels of Furin and TGF-β1 were elevated after infarction (p<0.05). With prolonged time periods of myocardial infarction, protein levels of Furin and TGF-β1 were further increased. The level of miR-24 was positively correlated with left ventricular end-diastolic diameter, left ventricular systolic diameter, and left ventricular ejection fraction. However, the level of Furin or TGF-b1 was negatively correlated with the above parameters.ConclusionsThis study demonstrated the important role of abnormal expression of miR-24 in myocardial fibrosis after infarction, and may provide drug targets for treating myocardial fibrosis.

Digital radiography in the diagnosis of coronary calcinosis: capabilitites and perspectives

Aim. To study the capabilities of digital radiography in the diagnosis of coronary calcifications and to perform a comparative analysis of the received results with the results of multidetector computed tomography. &#x0D; Methods. We analyzed in a comparative aspect the results of examination of 90 patients who underwent both types of diagnostic procedures. Among the patients, 46 were males, 34 were females, the average age was 59±4.3 years, and the age of male patients was significantly higher than that of female patients. Statistical analysis was performed using variational, discriminant, correlation methods, evidence-based medicine methods and ROC-analysis. &#x0D; Results. A comparative analysis of the results showed that the reason, why coronary calcifications visualized in all arteries at multidetector computed tomography are not visible on digital X-ray, is their decreased firmness, so these calcifications were soft enough. Visualization of calcifications on digital chest X-ray is limited to certain calcium score values, which for anterior interventricular branch of left coronary artery is 355, for circumflex branch of the left coronary artery - 385, for right coronary artery - 367, for left main coronary artery - 393, for aortic arch - 396. Coronary calcifications with similar and higher calcium score values can be detected with digital radiography, which allows integrating this method in screening for cardiovascular diseases risk. The sensitivity, specificity and overall value of digital radiography for the detection of coronary calcifications were 59.5±3.3, 85.5±2.9 and 70.0±2.4, respectively. &#x0D; Conclusion. Detection of coronary calcifications in digital radiography is limited to certain calcium score values; in all coronary arteries at multidetector computed tomography, as the calcium score of coronary calcifications increases, the sensitivity and spesifity of their visualization in digital X-ray examination increase as well.

Aspiracija tromba tokom primarne perkutane koronarne intervencije - gde smo sada?

Introduction. thrombus aspiration is not recommended as a routine procedure considering the results of large randomised trials. It is necessary to define new indications for thrombus aspiration in myocardial infarction and to conduct appropriate trials. The aim of this paper was to report a patient with successful aspiration of large thrombus mass from right coronary artery made after primary balloon angioplasty, and to consider which patients could benefit with this procedure. Case report. a male, 80 years old, has been admitted to a catheterisation laboratory with clinical, biochemical and electrocardiographic signs of acute myocardial infarction with ST segment elevation (STEMI) of inferoposterolateral localisation along with sinus bradycardia and profound arterial hypotension, which all are characteristic for inferior myocardial wall infarction with right ventricular involvement. Two hours after pain onset the patient was admitted to hospital in Bijeljina and sent to catheterisation laboratory straight after. All branches of left coronary artery were well visualized and without significant stenosis. Right coronary artery was occluded in proximal segment. Predilatation was performed with SC Sprinter legend 2,0x20mm balloon. After predilatation thrombus burden is still large, blood flow was slow with significant residual stenosis. Than, BMS Pro-kinetic energy 3,5x20mm stent was implanted. After stent implantation thrombus burden existed and there was no flow in PLV branch. Thrombus mass was 2 cm long and successfully aspirated with Export aspiration catheter. Control coronarography showed no residual stenosis and normal blood flow was restored through branches of right coronary artery. Conclusion. Procedure must be gradual, carefully planned and aspiration of thrombus should be taken only after initial balloon angioplasty with flow evaluation. Large thrombus burden or several smaller thrombi with clear flow obstruction and poor peripheral flow could be the reason for aspiration of thrombus along with possible intracoronary administration of GP IIbIIIa inhibitors. If conducted cautiously, aspiration of thrombus may still be considered as a valuable technique in selected patients with a large angiographic thrombus burden.

A cadaveric study of variation in branching pattern of left coronary artery

Background & ObjectivesCoronary artery disease increasing today due to because of change life style and diseases like diabetes and hypertension etc. Knowledge of normal and variation in coronary artery is important in management of coronary artery disease and congenital heart diseases. In this study we observed the branching pattern of left coronary artery in North Indian population. Material and methodStudy carried out on 50 formalin fixed heart obtained from anatomy Department during period of 3 years. ResultThe most frequent termination pattern was bifurcation (74%), followed by trifurcation (18%), quadrifurcation (6%) and pentafurcation (2%). ConclusionsHigh degree of variability in left coronary artery branching pattern required extra caution during interventional coronary angiography and surgery.

Isolated Unilateral Absence of Pulmonary Artery: Adult Manifestations of a Congenital Disease

SESSION TITLE: Student/Resident Case Report Poster - Pulmonary Vascular Disease I SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Unilateral absence of pulmonary artery (UAPA) is a rare congenital disorder. In the absence of other lesions, is survivable into adulthood. Adult patients can present with chest pain (CP), dyspnea on exertion (DOE), recurrent infections, or hemoptysis. Clinical diagnosis is difficult without radiographic support. CASE PRESENTATION: 56 year-old female former smoker with moderate obstructive lung disease presented for second opinion after multiple hospital admissions for CP, DOE and recurrent bronchitis. Hyper-inflated left lung, right mediastinal shift, and absent right hilar shadow noted on chest x-ray (CXR). CT angiogram revealed hypoplastic right lung with right greater left centrilobular emphysema, right nodularity, ground glass, and abrupt cessation right pulmonary artery. Right and left heart catheterization revealed mean pulmonary pressure of 27, and large arterial fistula between the left circumflex coronary artery and several branches of the right pulmonary vasculature. CT coronaries showed proximal interruption of the right pulmonary artery with collateral vasculature recruited from SA nodal branch of the left circumflex, bronchial, internal mammary, intercostal, and phrenic arteries. DISCUSSION: Adult patients with isolated UAPA are often asymptomatic. Common presentations are pulmonary infections, CP, DOE, hemoptysis or pulmonary hypertension (PAH). CXR shows ipsilateral contracted lung with mediastinal, tracheal shift toward the affected side, absent hilar shadow, and contralateral lung hyperinflation. Diagnosis is confirmed with contrast-enhanced CT. Recurrent infections can be secondary to poor blood flow to the affected lung, reduced delivery of inflammatory cells and impaired ciliary function. Decreased blood flow can also result in alveolar hypocapnia causing secondary bronchoconstriction and mucus trapping. PAH results from increased blood flow to the contralateral pulmonary artery, increased shear endothelial stress, and release of vasoconstrictors. Our patient's chest pain was felt not due to coronary steal as cardiac stress testing was negative. There is no clear consensus on treatment for UAPA other than symptom management. CONCLUSIONS: Although isolated UAPA is a congenital abnormality, it can remain undetected until adulthood. Clinicians need to be aware of characteristic CXR findings that may suggest UAPA. . Reference #1: Harke, A et al. Isolated Unilateral Absence of a Pulmonary Artery: A Case Report and Review of the Literature.” CHEST 2002; (122.4) 1471-477. Reference #2: Yiu MWC et al. Radiological features of isolated unilateral absence of the pulmonary artery. J HK Coll Radiol. 2001;4:277-280. Reference #3: Kruzliak, P et al. Unilateral Absence of Pulmonary Artery: Pathophysiology, Symptoms, Diagnosis and Current Treatment. Archives of Cardiovascular Diseases 2013; 106.8-9: 448-54 DISCLOSURE: The following authors have nothing to disclose: Santosh Reddy, Kimberly Cao No Product/Research Disclosure Information

Role of ATP-sensitive K+ channels in oxycodone postconditioning-induced attenuation of myocardial ischemia-reperfusion injury in rats

Objective To evaluate the role of ATP-sensitive K+ channels (KATP channels) in oxycodone postconditioning-induced attenuation of myocardial ischemia-reperfusion (I/R) injury in rats. Methods Forty healthy adult male Sprague-Dawley rats, aged 8-12 weeks, weighing 200-300 g, were randomly divided into 4 groups (n=10 each) using a random number table: sham operation group (group S), group I/R, oxycodone postconditioning group (group OP), and KATP channel blocker glibenclamide plus oxycodone postconditioning group (group GOP). Myocardial I/R was produced by 30 min occlusion of the anterior descending branch of the left coronary artery followed by 120 min reperfusion.In group S, the anterior descending branch of the left coronary artery was only exposed but not ligated.In group GOP, glibenclamide 1 mg/kg was injected via the jugular vein before ischemia.In OP and GOP groups, oxycodone 0.5 mg/kg was injected via the jugular vein at 5 min prior to reperfusion, and the equal volume of normal saline was given in S and I/R groups.At 120 min of reperfusion, blood samples were collected from the carotid artery for determination of the level of serum cardiac troponin I (cTnI). The animals were then sacrificed, and the hearts were removed for determination of the myocardial infarct size in the left ventricle. Results Compared with group S, the concentration of serum cTnI and myocardial infarct size were significantly increased in I/R, OP and GOP groups (P<0.05). Compared with group I/R, the concentration of serum cTnI and myocardial infarct size were significantly decreased in OP and GOP groups (P<0.05). Compared with group OP, the concentration of serum cTnI and myocardial infarct size were significantly increased in group GOP (P<0.05). Conclusion KATP channel opening is involved in oxycodone postconditioning-induced attenuation of myocardial I/R injury in rats. Key words: KATP channels; Oxycodone; Ischemic postconditioning; Myocardial reperfusion injury

Cadaveric study of branching pattern of left coronary artery

Abstract Background and aim: The branching pattern of vascular system has been the subject of much discussion and debate since it was first suggested that these systems have fractal architecture. Coronary arteries of human heart and their branching pattern have been the subject of particular attention among researchers. Hence, this study of branching pattern ofleft coronary artery (LCA) has been undertaken to highlight the variations of branches of left coronary arterial system. Material and methods: The study material consisted of 50 heart specimens obtained from the cadavers of Anatomy and Forensic departments which were studied by the conventional dissection method. Results: Left posterior aortic sinus gave origin to left coronary artery in all specimens with 90% ostium being below the level of sinotubular junction (STJ). Nearly 50% specimens were of the length ranging between 6-lOmm.Left coronary artery bifurcated into its two main branches in 62%, trifurcated in 32% and quadfurcated in 6%. Among the 16 trifurcating specimens, in five specimens the diagonal artery was seen at the junction of its two main branches, in 11 specimens the diagonal artery was found arising from the anterior interventricular artery and an additional branch the "Median Artery" was seen at the junction. Conclusion : Recent technical advances in the study of coronary arteries make it necessary for all angiographers and cardiac surgeons to be familiar with the variants of left coronary artery branching pattern.

A transradial percutaneous coronary intervention for complex lesions of the left main coronary artery and first obtuse marginal branch using a 7 French guiding catheter: a case report.

A transradial percutaneous coronary intervention for complex lesions of the left main coronary artery and first obtuse marginal branch using a 7 French guiding catheter: a case report.

Effect of sufentanil on autophagy during myocardial ischemia-reperfusion in rats

Objective To evaluate the effect of sufentanil on autophagy during myocardial ischemia-reperfusion(I/R)in rats. Methods Eighteen adult male Sprague-Dawley rats, weighing 200-250 g, were randomly divided into 3 groups(n=6 each)using a random number table: sham operation group(group SH), I/R group, and sufentanil group(group S). Myocardial I/R injury was produced by occlusion of the anterior descending branch of the left coronary artery for 30 min followed by 120 min reperfusion in the rats anesthetized with chloral hydrate in I/R and S groups.Sufentanil 3 μg/kg was injected via the caudal vein at 30 min prior to ischemia in group S. The equal volume of normal saline was given in SH and I/R groups.At 120 min of reperfusion, arterial blood samples were collected for determination of serum creatine kinase-MB(CK-MB)and lactic dehydrogenase(LDH)concentrations, and myocardial specimens were obtained for examination of the ultrastructure of myocardial cells(using transmission electron microscopy)and for determination of autophagy-related proteins microtubule-associated protein 1 light chain 3 Ⅱ(LC3Ⅱ), Beclin-1 and Bcl-2 expression(by Western blot). Results Compared with group SH, the serum CK-MB and LDH concentrations were significantly increased, the expression of LC3Ⅱ and Beclin-1 was significantly up-regulated, and Bcl-2 expression was significantly down-regulated in group I/R, and the serum CK-MB concentration was significantly increased, the expression of Beclin-1 and Bcl-2 was significantly down-regulated in group S(P 0.05), and the pathological changes were reduced in group S. Conclusion The mechanism by which sufentanil reduces myocardial I/R injury may be related to decreased autophagy in rats. Key words: Sufentanil; Myocardial reperfusion injury; Autophagy

Role of JAK2/STAT3 signaling pathway in brain injury induced by myocardial ischemia-reperfusion in diabetic rats

Objective To evaluate the effects of Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) signaling pathway on the brain injury induced by myocardial ischemia-reperfusion (I/R) in diabetic rats. Methods Pathogen-free male Sprague-Dawley rats, weighing 200-220 g, were used in this study.Diabetes mellitus was induced by intraperitoneal 1% streptozotocin 60 mg/kg and confirmed by blood glucose level ≥16.7 mmol/L 3 days later.Twenty-four rats with diabetes mellitus were randomly allocated into 3 groups (n=8 each) using a random number table: sham operation group (group S), I/R group, and myocardial I/R + AG490 (JAK inhibitor) group (group IA). Myocardial I/R was induced by occlusion of the anterior descending branch of the left coronary artery for 30 min, followed by 120 min of reperfusion in the rats anesthetized with pentobarbital sodium.AG490 3 mg/kg was injected intravenously at 20 min before reperfusion in group IA.The rats were sacrificed at 120 min of reperfusion, and the brains were removed for determination of caspase-3 and nuclear factor kappa B (NF-κB) activities (using colorimetric method), cell apoptosis (by TUNEL), and expression of interleukin-1 (IL-1), IL-6, IL-8, Bax, Bcl-2, cytochrome C (Cyt c), phosphorylated JAK2 (p-JAK2), and phosphorylated STAT3 (p-STAT3) (by Western blot). Apoptosis index was calculated. Results Compared with group S, the expression of Bax, Cyt c, IL-1, IL-6, IL-8, p-JAK2 and p-STAT3 was significantly up-regulated, the expression of Bcl-2 was down-regulated, and NF-κB and caspase-3 activities and apoptosis index were increased in I/R and IA groups (P<0.05). Compared with group I/R, the expression of Bax, Cyt c, IL-1, IL-6, IL-8, p-JAK2 and p-STAT3 was significantly down-regulated, the expression of Bcl-2 was up-regulated, and NF-κB and caspase-3 activities and apoptosis index were decreased in group IA (P<0.05). Conclusion Inflammatory responses mediated by JAK2/STAT3 signaling pathway are involved in the brain injury induced by myocardial I/R in diabetic rats. Key words: Janus kinase 2; STAT3 transcription factor; Diabetes mellitus; Myocardial reperfusion injury; Brain injuries

A case of the right coronary artery acute myocardial infarction with chronic total occulusion of the left coronary artery and circumflex branch showing cardiogenic shock

A case of the right coronary artery acute myocardial infarction with chronic total occulusion of the left coronary artery and circumflex branch showing cardiogenic shock

Hemopericardium after Lung Lobectomy

Cardiac tamponade after lung resection is a very rare but life-threatening complication. The present case illustrates another of this uncommon complication, wherein the exact mechanism of injury remained undefined. Hemorrhagic cardiac tamponade occurred few hours after left lower lung lobectomy and re-thoracotomy surprisingly revealed that a left coronary artery branch rupture was the cause.

Role of vagus nerve-muscarinic cholinergic receptor pathway in mitigation of myocardial ischemia-reperfusion injury by intrathecal morphine postconditioning in rats

Objective evaluate the role of vagus nerve-muscarinic cholinergic receptor (M receptor) pathway in mitigation of myocardial ischemia-reperfusion (I/R) injury by intrathecal morphine postconditioning in rats. Methods Seventy adult male Sprague-Dawley rats in which intrathecal catheters were successfully placed without complications, weighing 250-350 g, were randomly assigned into 7 groups (n=10 each) using a random number table: sham operation group (Sham group) , I/R group, intrathecal morphine postconditioning group (MP group) , vagal transection (VT) group, VT+ intrathecal morphine postconditioning group (VT+ MP group) , atropine (ATP, M receptor antagonist) + morphine postconditioning group (ATP+ MP group) , and ATP group. Myocardial I/R was produced by occlusion of the anterior descending branch of left coronary artery for 30 min followed by 2 h of reperfusion. Morphine (3 μg/kg, 10 μl) was intrathecally infused over 5 min starting from onset of reperfusion in MP group. Normal saline 10 μl was intrathecally infused over 5 min starting from onset of reperfusion in NS group. The bilateral vagus nerves were transected at 10 min before reperfusion in VT+ MP group. Atropine (0.1 mg/kg, 0.5 ml) was intravenously infused over 5 min starting from 10 min before reperfusion in ATP+ MP group. The occurrence of cardiac arrhythmia (premature ventricular contractions (PVCs) and ventricular tachycardia (VT) /ventricular fibrillation (VF) ) within the first 30 min of reperfusion was recorded. The rats were sacrificed at 120 min of reperfusion, and myocardial specimens were obtained for determination of myocardial infarct size (IS) as a percentage of area at risk (AAR) . IS/AAR ratio was calculated. Results Compared with Sham group, the number of PVCs and VT/VF and IS/AAR ratio were significantly increased in the other groups. Compared with I/R group, the number of PVCs and VT/VF and IS/AAR ratio were significantly decreased in MP group. Compared with MP group, the number of PVCs and VT/VF and IS/AAR ratio were significantly increased in VT+ MP and ATP+ MP groups. Conclusion Vagus nerve-M receptor pathway is involved in mitigation of myocardial I/R injury by intrathecal morphine postconditioning in rats. Key words: Vagus nerves; Receptors, muscarinic; Morphine; Injections, spinal; Myocar-dial reperfusion injury; Ischemic postconditioning

Effect of remifentanil preconditioning on myocardial ischemia-reperfusion injury in aged rats

Objective To evaluate the effect of remifentanil preconditioning on myocardial ischemia-reperfusion (I/R) injury in aged rats. Methods Twenty-four healthy male Sprague-Dawley rats, aged 15-18 months, weighing 465-580 g, were randomly divided into 3 groups (n = 8 each) using a random number table: sham operation group (group S), group I/R and remifentanil preconditioning group (group RP). The animals were anesthetized with intraperitoneal 10% chloral hydrate 300 mg/kg.Myocardial I/R was induced by 30 min occlusion of anterior descending branch of left coronary artery followed by 120 min reperfusion in group I/R.In group RP, remifentanil 10 μg · kg-1· min-1 was infused intravenously for 20 min followed by 10 min washout before myocardial I/R.In group S, the anterior descending branch was only exposed but not ligated.At 30 min before ligation and 120 min of reperfusion, the activities of serum lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) were determined.The hearts were removed at 120 min of reperfusion for determination of myocardial infarct size, the percentage of myocardial infarct size was calculated, and myocardial specimens were obtained for observing myocardial ultrastructure. Results Compared with group S, the activities of serum LDH and CK-MB were significantly increased at 120 min of reperfusion in I/R and RP groups.Compared with group I/R, the activities of serum LDH and CK-MB were significantly decreased, the percentage of myocardial infarct size was decreased, and the pathological changes were attenuated in group RP. Conclusion Remifentanil preconditioning can attenuate myocardial I/R injury in aged rats. Key words: Piperidines; Ischemic preconditioning; Myocardial reperfusion injury; Aged

Effect of hydrogen-rich saline postconditioning on expression of vascular endothelial growth factor receptor-1 during myocardial ischemia-reperfusion injury in rats

Objective To investigate the effect of hydrogen-rich saline postconditioning on the expression of vascular endothelial growth factor receptor-1 (VEGFR1) during myocardial ischemia-reperfusion (I/R) injury in rats. Methods Thirty-six adult male Sprague-Dawley rats, weighing 250-280 g, were randomly divided into 3 groups (n=12 each) using a random number table: sham operation group (group S), group I/R and hydrogen-rich saline group (group H2). Myocardial I/R was induced by 30 min ligation of anterior descending branch of the left coronary artery followed by 2 h reperfusion.In group H2, hydrogen-rich saline 5 ml/kg was injected intravenously at 5 min before reperfusion, while the equal volume of normal saline was given in group I/R.Left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and ± dp/dtmax were measured and recorded during reperfusion and at 120 min of reperfusion.The rats were sacrificed at 120 min of reperfusion, and myocardial specimens were obtained for determination of myocardial infarct size, contents of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) (using ELISA), and expression of VEGFR1 (by Western blot). At 120 min of reperfusion, blood samples were collected from the common carotid artery to measure cardiac troponin I (cTnI) concentrations in serum. Results Compared with group S, LVSP and ± dp/dtmax were significantly decreased, LVEDP was increased, the myocardial infarct size was enlarged, cTnI concentrations in serum and contents of IL-6 and TNF-α were increased, and the expression of VEGFR1 was down-regulated at 120 min of reperfusion in H2 and I/R groups.Compared with group I/R, LVSP and ± dp/dtmax were significantly increased, LVEDP and myocardial infarct size were decreased, cTnI concentrations in serum and contents of IL-6 and TNF-α were decreased, and the expression of VEGFR1 was up-regulated at 120 min of reperfusion in group H2. Conclusion Hydrogen-rich saline postconditioning can reduce myocardial I/R injury possibly by up-regulating myocardial VEGFR1 expression and inhibiting inflammatory responses in the myocardium of rats. Key words: Hydrogen; Myocardial Reperfusion injury; Vascular endothelial growth factorreceptor-1; Ischemic postconditioning

Transesophageal echocardiography estimation of coronary sinus blood flow for the adequacy of revascularization in patients undergoing off-pump coronary artery bypass graft.

Aims and Objectives:Physiologically coronary sinus (CS) drains the left coronary artery (LCA) territory. Stenosis of the branches of LCA may decrease the coronary sinus blood flow (CSBF). Any intervention that aims at restoring the flow of the stenosed vessel increases coronary artery flow that should consequently increase the CSBF. Hence, this study was undertaken to assess the CSBF before and after each branch of LCA to determine the adequacy of surgical revascularization in patients undergoing elective off pump coronary artery bypass grafting (OPCAB) using transesophageal echocardiography (TEE).Materials and Methods:Thirty consecutive patients scheduled for elective OPCAB were enrolled. CSBF was assessed before and after each branch of LCA revascularization using TEE. Left internal mammary artery (LIMA) Doppler was also obtained post LIMA to left anterior descending (LAD) grafting.Results:Hemodynamic and echocardiographic variables were compared by means of Student's t-test for paired data before and after revascularization. The CSBF per beat (1.28 ± 0.71), CSBF per minute (92.59 ± 59.32) and total velocity time integral (VTI) (8.93 ± 4.29) before LAD grafting showed statistically significant increase to CSBF per beat (1.70 ± 0.89), CSBF per minute (130.72 ± 74.22) and total VTI (11.96 ± 5.68) after LAD revascularization. The CSBF per beat (1.67 ± 1.03), CSBF per minute (131.91 ± 86.59) and total VTI (11.00 ± 5.53) before obtuse marginal (OM) grafting showed statistically significant increase to CSBF per beat (1.91 ± 1.03), CSBF per min (155.20 ± 88.70) and total VTI (12.09 ± 5.43) after OM revascularization. In 9 patients, color flow Doppler of LIMA could be demonstrated which showed diastolic predominant blood flow after LIMA to LAD grafting.Conclusion:Demonstration of CSBF was simple and monitoring the trend of CSBF values before and after each graft of LCA territory will guide to determine the adequacy of surgical revascularization.

Intima – Media Thickness of Left Anterior Descending Coronary Artery in a Black Kenyan Population: Correlation with Morphological Features

Background: Intima-Media thickness is an acknowledged surrogate marker for predicting and profiling of atherosclerotic cardiovascular disease. It displays geographical and ethnic variation but is seldom reported among black populations of Africa. The left anterior descending coronary artery is one of the most frequently afflicted arteries by atherosclerosis. This study, therefore, aimed at correlating its intima – media thickness with morphological features of left coronary artery in a black Kenyan population. Materials and methods: Materials for this study were 126 hearts obtained during autopsy at the Department of Human Anatomy, University of Nairobi Kenya from black adult Kenyans [72 males, 54 females] who died of noncardiovascular causes. The left coronary artery was identified, its termination pattern recorded and its length and bifurcation angle measured. Specartery and procesimens for light microscopy were taken from the proximal segment of the left anterior descending sed for paraffin embedding and sectioning. Five micron sections were stained with Masson’s trichrome and examined at magnification x35. The results were analyzed using SPSS version 17.0. Student t-test was performed at 95% confidence interval where p ≤ 0.05 was taken to be statistically significant. They are presented in micrographs and tables. Results: The mean intima – media thickness was 0.332 mm. It was higher in males (0.357 ± 0.06 mm) than in females (0.25 ± 0.03 mm), increased with number of branches of left coronary artery, from 0.336 ± 0.014 mm in bifurcation to 0.506 ± 0.01 mm in pentafurcation; and was also higher in left coronary arteries that were shorter than 5 mm and those with bifurcation angles >800. Conclusion: The intima – media thickness of left anterior descending artery is influenced by length, bifurcation angle and terminal branching pattern of left coronary artery, and is higher in males than in females. This suggests that these morphological features of left coronary artery constitute anatomical risk factors for atherosclerosis. Individuals with these features should be screened for atherosclerosis, to inform early intervention.

Effect of remote limb ischemic postconditioning on level of adiponectin during myocardial ischemia-reperfusion in rats

Objective To evaluate the effect of remote limb ischemic postconditioning on the level of adiponectin during myocardial ischemia-reperfusion (I/R) in rats.Methods Fifty-seven male Sprague-Dawley rats,aged 8 weeks,weighing 250-350 g,were randomly divided into 3 groups (n =19 each):sham operation group (group S); group I/R; remote limb ischemic postconditioning group (group RLIP).Myocardial ischemia was induced by occlusion of anterior descending branch of left coronary artery for 30 min followed by 180 min reperfusion in urethane-anesthetized rats.In group S,the anterior descending branch was only exposed but not ligated.The animals underwent 10 min ischemia of bilateral hind limbs starting from 20 min of occlusion of the anterior descending branch,followed by reperfusion in RLIP group.The changes in S-T segment were recorded at 30,60,120 and 180 min of reperfusion.At 180 min of reperfusion,the blood samples were taken from the jugular vein for determination of serum levels of creatine kinase MB (CK-MB) and cardiac troponin Ⅰ (cTnⅠ).The animals were then sacrificed and hearts were removed for measurement of myocardial infarct size (IS) and adiponectin contents in myocardial tissues (by ELISA).Results Compared with group S,S-T segment was significantly elevated at each time point,myocardial IS,and serum cTnⅠ and CK-MB levels were increased,and adiponectin contents were decreased in I/R and RLIP groups.Compared with group I/R,elevation of S-T segment was significantly decreased at each time point,myocardial IS,and serum cTnⅠ and CK-MB levels were decreased,and adiponectin contents were increased in RLIP group.Conclusion The mechanism by which remote limb ischemic postconditioning reduces myocardial I/R injury is related to increased level of adiponectin in the myocardium of rats. Key words: Adiponectin ; Myocardial reperfusion injury ; Extremities ; Ischemic postconditioning