Reperfusion Strategies in Acute Myocardial Infarction: State of the Art

Abstract ST elevation myocardial infarction (STEMI) is a highly prevalent condition worldwide. Reperfusion therapy is strongly associated with the prognosis of STEMI and must be performed with a high standard of quality and without delay. A systematic review of different reperfusion strategies for STEMI was conducted, including randomized controlled trials that included major cardiovascular events (MACE), and systematic reviews in the last 5 years through the PRISMA ( Preferred Reporting Items for Systematic Reviews and Meta-Analysis) methodology. The research was done in the PubMed and Cochrane Central Register of Controlled Trials databases, in addition to a few manual searches. After the exclusion criteria were applied, 90 articles were selected for this review. Despite the reestablishment of IRA patency in PCI for STEMI, microvascular lesions occur in a significant proportion of these patients, which can compromise ventricular function and clinical course. Several therapeutic strategies - intracoronary administration of nicorandil, nitrates, melatonin, antioxidant drugs (quercetin, glutathione), anti-inflammatory substances (tocilizumab [an inhibitor of interleukin 6], inclacumab, P-selectin inhibitor), immunosuppressants (cyclosporine), erythropoietin and ischemic pre- and post-conditioning and stem cell therapy - have been tested to reduce reperfusion injury, ventricular remodeling and serious cardiovascular events, with heterogeneous results: These therapies need confirmation in larger studies to be implemented in clinical practice

Anesthesia management for a patient undergoing pulmonary endarterctomy without cardiopulmonary bypass

Abstract Pulmonary endarterectomy is a curative procedure for chronic thromboembolic Pulmonary Hypertension. As usual, cardiopulmonary bypass circuit is required. However, there are several complications attributed to extracorporeal circulation. Hemodilution, systemic inflammatory response syndrome and leukocyte sequestration are circulation related complications. The severe forms include Acute Respiratory Distress Syndrome, Acute Lung Injury, myocardial stunning, dysfunction of the right ventricle, coagulopathy, postoperative stroke or renal dysfunction. In this case report, we aimed to give information about perioperative anesthesia and surgical management of pulmonary endarterectomy which was successfully managed without Cardiopulmonary Bypass.

Myocardial viability: from PARR-2 to IMAGE HF - current evidence and future directions / Viabilidade miocárdica: de PARR-2 a IMAGE HF - evidências atuais e futuras direções

Ischemic heart failure is a growing disease with high morbidity and mortality. Several studies suggest the benefit of viability imaging to assist revascularization decision, but there is controversy. Multiple imaging modalities can be used to accurately define hibernating myocardium; however, the best approach remains uncertain. This review will highlight current evidence and future directions of viability imaging assessment

Reperfusing the myocardium - a damocles Sword

Return of blood flow after periodic ischemia is often accompanied by myocardial injury, commonly known as lethal reperfusion injury (RI). Experimental studies have shown that 50% of muscle die of ischemia and another 50% die because of reperfusion. It is characterized by myocardial, vascular, or electrophysiological dysfunction that is induced by the restoration of blood flow to previously ischemic tissue. This phenomenon reduces the efficiency of the present modalities used to combat the ischemic myocardium. Moreover, despite an improved understanding of the pathophysiology of this process and encouraging preclinical trials of multiple agents, most of the clinical trials to prevent RI have been disappointing and leaves us at ground zero to explore newer approaches.

New thoughts in mechanism research of acupuncture for myocardial stunning from κ-opioid receptor signaling pathway / 中国针灸

By reviewing the literature regarding the development mechanism of myocardial stunning, effects of acupuncture on myocardial ischemic injury, and correlation between acupuncture and κ-opioid receptor, it was suggested that acupuncture was highly likely to act on κ-opioid receptor in myocardial cells, and directly treated myocardial malfunction induced by myocardial stunning through κ-opioid receptor and its signaling pathway. In addition, acupuncture could inhabit the signaling pathway of adrenoceptor β1, one of the main functional receptors, to indirectly improve myocardial ischemic injury. From κ-opioid receptor signaling pathway, the action mechanism of acupuncture for prevention and treatment of myocardial stunning was discussed in this paper, hoping to provide new ideas for possible mechanism of acupuncture for myocardial ischemic injury.

Reconsideration of the role of viable myocardium in revascularization / 中华核医学与分子影像杂志

Recent studies on the role of viable myocardium in revascularization are hot spots.The definition of viable myocardium,multimodality imaging in the assessment of myocardial viability,Meta analyses related to the value of viable myocardium in revascularization,prospective randomized trials,and factors affecting the prognosis of patients after revascularization are reviewed in this article.

Atrial Strain and Strain Rate: A Novel Method for the Evaluation of Atrial Stunning / Strain Atrial e Strain Rate: Novo Método para Avaliar Atordoamento Atrial

Abstract Background: Atrial fibrillation (AF) is the most common arrhythmia seen in adults. Atrial stunning is defined as the temporary mechanical dysfunction of the atrial appendage developing after AF has returned to sinus rhythm (SR). Objectives: We aimed to evaluate atrial contractile functions by strain and strain rate in patients with AF, following pharmacological and electrical cardioversion and to compare it with conventional methods. Methods: This study included 41 patients with persistent AF and 35 age-matched control cases with SR. All the AF patients included in the study had transthoracic and transesophageal echocardiography performed before and after. Septum (SEPsSR), left atrium (LAsSR) and right atrium peak systolic strain rate (RAsSR) were defined as the maximum negative value during atrial contraction and septum (SEPε), left atrium (LAε) and right atrium peak systolic strain (RAε) was defined as the percentage of change. Parameters of two groups were compared. Results: In the AF group, 1st hour and 24th hour LAε, RAε, SEPε, LAsSR, RAsSR, SEPsSR found to be significantly lower than in the control group (LAε: 2.61%±0.13, 3.06%±0.19 vs 6.45%±0.27, p<0.0001; RAε: 4.03%±0.38, 4.50%±0.47 vs 10.12%±0.64, p<0.0001; SEPε: 3.0%±0.22, 3.19%±0.15 vs 6.23%±0.49, p<0.0001; LAsSR: 0.61±0.04s-1, 0.75±0.04s- 1 vs 1.35±0.04s-1, p<0.0001; RAsSR: 1.13±0.06s-1, 1.23±0.07s-1 vs 2.10±0.08s- 1, p<0.0001; SEPsSR: 0.76±0.04s- 1, 0.78±0.04s- 1 vs 1.42±0.06 s- 1, p<0.0001). Conclusion: Atrial strain and strain rate parameters are superior to conventional echocardiographic parameters for the evaluation of atrial stunning in AF cases where SR has been achieved.

Resumo Fundamento: A fibrilação atrial (FA) é a arritmia mais comum em adultos. Define-se atordoamento atrial como a disfunção mecânica temporária do apêndice atrial que se desenvolve depois de reversão da FA ao ritmo sinusal (RS). Objetivos: Avaliar as funções atriais contráteis através de strain atrial e strain rate em pacientes com FA, após cardioversão farmacológica e elétrica, assim como compará-los com os métodos convencionais. Métodos: Este estudo incluiu 41 pacientes com FA persistente e 35 controles com RS e pareados por idade. Todos os pacientes com FA incluídos neste estudo foram submetidos a ecocardiografia transtorácica e transesofágica antes e após. Strain rates de pico sistólico do septo (SEPsSR), do átrio esquerdo (LAsSR) e do átrio direito (RAsSR) foram definidas como o máximo valor negativo durante contração atrial. Strains de pico sistólico do septo (SEPε), do átrio esquerdo (LAε) e do átrio direito (RAε) foram definidas como porcentagem de mudança. Resultados: No grupo com FA, os parâmetros LAε, RAε, SEPε, LAsSR, RAsSR e SEPsSR da 1a hora e da 24a hora foram significativamente mais baixos que no grupo controle (LAε: 2,61%±0,13; 3,06%±0,19 vs 6,45%±0,27; p<0,0001; RAε: 4,03%±0,38; 4,50%±0,47 vs 10,12%±0,64; p<0,0001; SEPε: 3,0%±0,22; 3,19%±0,15 vs 6,23%±0,49; p<0,0001; LAsSR: 0,61±0,04s-1; 0,75±0,04s-1 vs 1,35±0,04s-1; p<0,0001; RAsSR: 1,13±0,06s-1; 1,23±0,07s-1 vs 2,10±0,08s-1; p<0,0001; SEPsSR: 0,76±0,04s-1; 0,78±0,04s-1 vs 1,42±0,06 s-1; p<0,0001). Conclusão: Os parâmetros strain atrial e strain rate são superiores aos parâmetros ecocardiográficos convencionais para avaliar atordoamento atrial em pacientes com FA que reverteram ao RS.

Improvement of cardiac function after cardiopulmonary resuscitation by using isosorbide ;mononitrate in porcine models / 中华急诊医学杂志

Objective To determine the protective effect of isosorbidemononitrate (IM) on myocardial injury after restoration of spontaneous circulation (ROSC)in swine models of cardiac arrest induced by ventricular fibrillation.Methods The experiment was carried out in Animal Lab of Beijing Chao-Yang Hospital,Capital Medical University.Ventricular fibrillation was induced and untreated for 8 min in twenty WhuZhiShan piglets.CPR was performed until ROSC occurred.The animals were randomized (random number)into two groups:IMgroup (n =10)and control group (n =10).IM [2 μg/(kg· min)]or the equivalent volume in saline was administered respectively for 6 h after ROSC.Hemodynamics and post-resuscitation cardiac function were monitored until 24 h after ROSC. Echocardiography and transmission electron microscopy were useed at 72 h after ROSC.Results There was no significant difference in survival rate between the two groups.No significant differences in mean arterial pressures (mmHg)at ROSC 6 h (88.5 ±5.6 vs.87.8 ±6.0,P =0.790)and ROSC 24 h (89.3 ±3.8 vs.86.9 ± 5.0,P =0.245)between the two groups were found.Cardiac outputs (L/min)were significantly increased at ROSC 6 h (2.40 ±0.17 vs.1.60 ±0.14,P <0.01)and ROSC 24 h (2.49 ±0.17 vs.2.09 ±0.21,P<0.01);and ejection fraction at ROSC 72 h (0.67 ±0.08 vs.0.56 ±0.09,P =0.044)was improved too,and significant differences were found between the two groups.The ultra-structural myocardial injury was ameliorated in the MI group at 72 h after CPR observed by using electron microscopy.Conclusions IM can ameliorate post-resuscitation cardiac dysfunction in porcine models of cardiac arrest induced by ventricular fibrillation.

Papel de la tiorredoxina-1 en el atontamiento cardíaco en ratones transgénicos / Role of Thioredoxin-1 on Myocardial Stunning in Transgenic Mice

Introducción: La disfunción ventricular posisquémica (miocardio atontado) involucra un aumento del estrés oxidativo. En este sentido, la célula cuenta con mecanismos de defensa, como la tiorredoxina-1, un antioxidante que protege al miocardio de la lesión por isquemia/reperfusión, reduciendo el tamaño del infarto. Objetivo: Evaluar el comportamiento de la función ventricular sistólica y diastólica, particularmente estudiando la rigidez miocárdica y la relajación isovolúmica en el miocardio atontado en diferentes ratones transgénicos. Material y métodos: Se utilizaron corazones de ratones que sobreexpresan tiorredoxina-1 y de ratones transgénicos que sobreexpresan tiorredoxina-1 mutada en su sitio activo (dominante negativo), comparados con los de ratones no transgénicos, los cuales fueron sometidos a 15 minutos de isquemia global y 30 minutos de reperfusión utilizando la técnica de Langendorff. Se evaluó la función ventricular sistólica y diastólica y se calculó el t63 y el t93 como índice de relajación isovolúmica. Resultados: Las mediciones a los 30 minutos de reperfusión mostraron una mejoría significativa del estado contráctil en los ratones tiorredoxina-1 (57,4 ± 4,9 mm Hg; p ≤ 0,05 vs. no transgénicos) y también en la rigidez (11,8 ± 2,9 mm Hg; p ≤ 0,05 vs. no transgénicos). Por otra parte, en los ratones dominantes negativos se observó un aumento de la rigidez (37,7 ± 5,5 mm Hg; p ≤ 0,05 vs. no transgénicos) y un enlentecimiento de la relajación a los 30 minutos de la reperfusión (78,2 ± 9,8 mseg; p ≤ 0,05 vs. no transgénicos). Conclusión: Este trabajo evidencia el rol protector de la tiorredoxina-1 en el miocardio atontado y su importancia fisiopatológica en ratones que sobreexpresan este antioxidante.

Background: Postischemic ventricular dysfunction (myocardial stunning) involves increased oxidative stress. In this sense, the cell has defense mechanisms, as thioredoxin-1, an antioxidant that protects the myocardium from ischemia/reperfusion injury, reducing infarct size. Objective: The aim of this study was to evaluate systolic and diastolic ventricular function, specifically analyzing myocardial stiffness and isovolumic relaxation, during myocardial stunning in different transgenic mice. Methods: Hearts from mice overexpressing thioredoxin-1 and transgenic mice overexpressing thioredoxin-1 with gene mutation in its active site (dominant negative) were compared with hearts from non-transgenic mice after 15-minute global ischemia and 30-minute reperfusion using the Langendorff technique. Systolic and diastolic ventricular function was evaluated and t63 and t93 were calculated as ventricular relaxation index. Results: At 30-minute reperfusion, thioredoxin-1 mice showed a significantly improved contractile state (57.4±4.9 mmHg; p≤0.05 vs. non-transgenic mice) and stiffness (11.8±2.9 mmHg; p≤0.05 vs. non-transgenic mice). Conversely, at the same reperfusion time, dominant negative mice exhibited increased stiffness (37.7±5.5 mmHg; p≤0.05 vs. non-transgenic mice) and slower relaxation (78.2±9.8 ms; p≤0.05 vs. non-transgenic mice). Conclusion: This study reveals the protective role of thioredoxin-1 on myocardial stunning and its pathophysiological importance in mice overexpressing this antioxidant.

The relationship between sarcoplasmic reticulum Ca2+modulation proteins and postresuscitation myocardial dysfunction / 中华危重病急救医学

Objective To investigate the relationship between sarcoplasmic reticulum Ca2+modulation proteins and postresuscitation myocardial dysfunction. Methods Thirty-eight SPF male Sprague-Dawley (SD) rats were randomly divided into control group(n=12)and cardiac arrest(CA)group(n=26). CA was induced by intravenous bolus of potassium chloride(40μg/g),and cardiopulmonary resuscitation(CPR)was conducted 8 minutes later. No CA was induced in control group except catheter placement for monitoring cardiopulmonary parameters after anesthesia. Invasive hemodynamic parameters were monitored for 1 hour after CPR. Echocardiogram was performed to evaluate cardiac function. Myocardial samples were harvested 5 minutes and 1 hour after restoration of spontaneous circulation (ROSC),and sarcoplasmic reticulum Ca2+ ATPase (SERCA2a),phosphorylated phospholamban (p-PLB) and rynodine receptor(RyR)were determined by Western Blot. Results ROSC rate of CA group was 92.3%(24/26),and mean recovery time was (68 ±39)seconds. Cardiac function was significantly impaired in CA group at 1 hour after resuscitation, and ejection fraction, fraction shortening (FS), the maximal rate of left ventricular pressure increase/decline (±dp/dt max)were significantly decreased compared with those in control group 〔ejection fraction:0.548±0.060 vs. 0.809±0.043,F=71.692,P=0.000;FS:(34.4±4.4)%vs. (46.0±3.5)%,F=55.443,P=0.000;+dp/dt max(mmHg/s):4 718±743 vs. 7 098±394,P0.05). Conclusions The impairment of the p-PLB is closely related to postresuscitation myocardial dysfunction.

The Value of Assessing Myocardial Deformation at Recovery after Dobutamine Stress Echocardiography

BACKGROUND: The purpose of this study was to evaluate whether performing an assessment of myocardial deformation using speckle tracking imaging during the recovery period after dobutamine stress echocardiography (DSE) allows detection of significant coronary artery disease (CAD) in patients with chest discomfort. METHODS: DSE and coronary angiography were performed in 44 patients with chest discomfort. The mean global longitudinal peak systolic strain (GLS) was measured at rest, at low stress (dobutamine infusion rate of 10 microg/kg/min) and at recovery (5 min after cessation of dobutamine infusion) of DSE using automated function imaging with apical views. Fractional flow reserve (FFR) was also performed in patients with intermediate coronary stenosis. CAD was defined as having a > or = 70% diameter stenosis on coronary angiography or as having a FFR < 0.8. Patients were divided two groups based on the absence or presence of CAD [CAD (-) group vs. CAD (+) group]. RESULTS: There were no significant differences in the clinical characteristics and results of conventional echocardiography between the two groups. GLS at recovery was lower in the CAD (+) group than in the CAD (-) group (-18.0 +/- 3.4% vs. -21.0 +/- 1.9%, p = 0.003). The optimal cutoff of GLS at recovery for detection of CAD was -19% (sensitivity of 70.6%, specificity of 83.3%). CONCLUSION: Assessment of GLS at recovery of DSE is a reliable and objective method for detection of CAD. This finding may suggest that systolic myocardial stunning remains even after recovery of wall motion abnormalities in patients with CAD.

Detection of stunned myocardium using speckle tracking echocardiography combined with low-dose dobutamine stress / 中华超声影像学杂志

Objective To detect stunned myocardium using low-dose dobutamine stress (DBS)combined with two-dimensional speckle tracking imaging (2D-STI),and to evaluate the difference and characteristics of mechanical parameters in different conditions between stunned myocardium and adjacent normal myocardium.Methods The acute myocardium ischemia/reperfusion (I/R) of anterior wall of left ventricle(LV) was induced with 60 minutes ligation of left anterior descending coronary artery (LAD),and with reperfusion of 120 minutes in 10 open-chest beagle dogs.Dobutamine was administered continuously via vein with two different dose of 5 μg · kg-1 · min-1 and 10 μg · kg-1 · min-1.At baseline,post ischemia/reperfusion,after the first DBS and the second,the gray-scale dynamic images of three cardiac cycle of left ventricular short axis at the levels of mitral annulus,papillary muscle and apex were acquired.The systolic peak of circumferential strain (CS),radial displacement (RD) of eighteen segments of subendocardium and subepicardium were analyzed by Speckle tracking workstation.LV end-systolic dimension(LVIDS),LV end-diastolic dimension (LVIDD),LV eject fraction (LVEF),heart rate (HR),aortic valve forward flow velocity time integral(AV-VTI) were also measured.Results ①There was no statistical significance (P ＞0.05) under the conditions of baseline,post I/R,the first DBS and the second for LVIDD,LVIDS,LVEF,HR and AV-VTI.②Compared with baseline,the peak systolic subendocardium and subepicardium CS,RD decreased significantly at the apex and middle of short-axis anterior wall of LV under the conditions of post I/R;The parameters of the first DBS was significantly increased compared with the I/R (P ＜ 0.05) ; There was no difference between the two DBS and baseline(P ＞0.05).The peak systolic subendocardium and subepicardium CS,RD at the bottom segment of LV were no statistical significance under the four conditions.③There was no difference for anterolateral wall and anterior septum of LV at the level of papillary muscle under the four conditions.Conclusions ①Low-dose DBS combined with two-dimensional speckle tracking imaging can detect stunned myocardium accurately.② After the occurrence stunning myoeardium,the peak systolic subendocardium RD decreased slightly,subepicardium RD was normal,the subendocardium CS of the surrounding myocardium was still normal,and the peak systolic subepicardium CS decreased to some degree.

Effect of atorvastatin therapy before percutaneous coronary intervention on periprocedural myocardial injury / 中国基层医药

ObjectiveTo explore the effect of statin in reduction of my ocardial injury in patients undergoing percutaneous coronary intervention(PCI).MethodsTotal of 185 patients undergoing PCI were included,140 patients were received atorvastatin before PCI,while 145 were not given statins at the time of PCI.Creatine kinase-MB and troponin Ⅰ were measured at baseline and at 8 and 24 hours after the procedure.ResultsPost procedurul peak levels of troponin Ⅰ and creatine kinase-MB were(0.12 ±0.26) μg/L and(2.61 ± 3.07) μg/L in the observation group,which were significantly lower than(0.51 ± 1.14) μg/L and( 6.85 ± 14.38 ) μg/L in the control group( t =3.951,3.414,P ＜ 0.05).ConclusionPretreatment with atorvastatin for 7 days could significantly reduces procedural myocardial injury in elective PCI.

Effects of postconditioning with N,N,N'N'-tetrakis-2-pyridylmethyl-ethylenediamine in isolated rat hearts / 대한마취과학회지

BACKGROUND: It was reported that N,N,N'N'-tetrakis-[2-pyridylmethyl]-ethylenediamine (TPEN), a transition metal chelator, confers cardioprotection against myocardial ischemic injury. In this study, we investigated the effect of TPEN targeting reperfusion period in isolated rat hearts. METHODS: Langendorff perfused rat hearts were subjected to 30 min of regional ischemia and 2 h of reperfusion. Hearts were randomly assigned to either control (n = 9) or 10 micrometer of TPEN (n = 8) groups. TPEN was perfused for a period of 5 min before and 30 min after reperfusion. RESULTS: The ratio of infarct area/ischemic area (AN/AR) was significantly reduced in TPEN treated hearts (6.9 +/- 1.7%, P 0.05). CONCLUSIONS: Pharmacological postconditioning with TPEN reduces myocardial infarction however, TPEN does not modify post-ischemic systolic dysfunction in isolated rat hearts.

Síndrome do balonamento apical secundário ao uso abusivo de descongestionante nasal / Apical ballooning syndrome secondary to nasal decongestant abuse / Síndrome del abombamiento apical secundario al uso abusivo de descongestionante nasal

Descrevemos um caso típico de síndrome do balonamento apical em uma paciente octogenária com alteração eletrocardiográfica, de contratilidade do ventrículo esquerdo, e que apresentou recuperação da função ventricular. A paciente é portadora de rinite alérgica e fez uso excessivo de descongestionante nasal horas antes do episódio da dor.

We describe a typical case of apical ballooning syndrome in an octogenarian female patient with left ventricular wall motion abnormality on electrocardiography, whose ventricular function returned to normal. The patient has allergic rhinitis and had used nasal decongestant excessively a few hours prior to the episode of pain.

Describimos un caso típico de síndrome de abombamiento apical en una paciente octogenaria con alteración electrocardiográfica, de contractilidad del ventrículo izquierdo, y que presentó recuperación de la función ventricular. La paciente es portadora de rinitis alérgica y hace uso excesivo de descongestionante nasal horas antes del episodio del dolor.

Comparison of real-time myocardial contrast echocardiography and DISA-SPECT in dectecting hibernating myocardium / 中华超声影像学杂志

Objective To compare the accuracy of real-time myocardial contrast echocardiography (RT-MCE) with DISA-SPECT in detecting hibernating myocardium. Methods Fourteen hospitalized patients with regional wall motion abnormalities (RWMA) underwent RT-MCE, DISA-SPECT, coronary angiography and percutaneous coronary intervention(PCI). Every left ventricular myocardial segment image was acquired and evaluated according 16-segment model of American Society of Echocardiography. The Motion of every segment was observed by echocardiography after 1,3,6 months. The gold standard is that the motion of ventricular segment get better after PCI. The images of RT-MCE and DISA-SPECT were analyzed semi-quantitatively. Results The sensitivity,specificity,accuracy of RT-MCE and DISA-SPECT in detecting hibernating myocardium were 74.60%, 91.7%, 81.3% and 93.3%, 75.0%, 86.2%, respectively. RT-MCE had more value in specificity while DISA-SPECT had more value in sensitivity. The correlation between two methods was good in detecting hibernating myocardium. Conclusions RT-MCE and DISA-SPECT can be used as valuable methods to detect hibernating myocardium, the correlation between two methods is good and they have more value in specificity and sensitivity respectively.

Suspicious stress induced cardiomyopathy following hemorrhoidectomy under spinal anesthesia: A case report / 대한마취과학회지

A 48-year-old healthy woman was admitted in our hospital for elective hemorrhoidectomy. She developed sudden headache and chest pain, and showed sinus bradycardia, arrhythmia and hypotension forty minutes after spinal anesthesia with 0.5% hyperbaric bupivacaine. An EKG showed ST depression and an transthoracic echocardiogram performed in PACU demonstrated mild LV dysfunction with hypokinesia of LV inferolateral wall. An coronary angiography on postoperative day 1 revealed normal coronary vessel and akinesia of LV inferior wall. Levels of CK-MB and Troponin I were mildly elevated. With medical therapy, the patient's symptoms improved and recovered without any complication.