RESUMO
The present study aimed to analyze the effects of reperfusion of a distant coronary artery on cardiac function, the ultrastructure, and the molecular environment of the remote myocardium immediately after the completion of myocardial regional necrosis: delayed reperfusion (DR). Additionally, the effects of prior exercise on the outcomes of DR were investigated. Female rats with permanent occlusion or delayed reperfusion were randomly assigned to an exercise (swimming, 1 h/day, 5 days/week for 8 weeks) or sedentary protocol. Thus, the study included the following four groups: sedentary permanent occlusion, exercise permanent occlusion, sedentary delayed reperfusion, and exercise delayed reperfusion. The descending coronary artery was occluded for 1 h. Reperfusion was confirmed by contrast echocardiography, and the rats were observed for 4 weeks. Permanent occlusion and DR caused similar myocardial infarction sizes among the four groups. Interestingly, exercise significantly decreased the mortality rate. Delayed reperfusion resulted in significant benefits, including enhanced hemodynamics and papillary muscle contraction, as well as reduced apoptosis and collagen content. Protein calcium kinetics did not change. Meanwhile, developed tension and the Frank-Starling mechanism were enhanced, suggesting that calcium sensitivity was intensified in myofilaments. Remarkable remote myocardial benefits occurred after distant DR, and prior exercise intensified cardiac recovery. Our findings provide valuable information about DR. Our data might explain the better clinical outcomes in recent studies showing that late reperfusion could improve heart failure in patients with myocardial infarction. In conclusion, DR has remote myocardial benefits, including inotropism enhancement, pulmonary congestion reduction, and collagen and apoptosis attenuation, which are enhanced by prior exercise.
RESUMO
OBJECTIVE: To compare echocardiography (ECHO) findings of patients with congenital diaphragmatic hernia (CDH) who required extracorporeal membrane oxygenation (ECMO) to non-ECMO treated patients. STUDY DESIGN: We reviewed clinical and ECHO data of newborns with CDH born between 2009 and 2016. Exclusions included major anomalies, genetic syndromes, or no ECHO prior to ECMO. Pulmonary hypertension was assessed by ductal shunting and tricuspid regurgitant jet. Speckle tracking echocardiography (STE) assessed function by quantifying deformation. RESULTS: Patients with CDH (15 ECMO and 29 with no ECMO) were analyzed. Most patients had a left CDH (88.6%). Age at ECHO was similar between groups. Outborn status (P = .009) and liver position (P = .009) were associated with need for ECMO. Compared with non-ECMO patients, patients who required ECMO had significantly decreased left and right ventricular function by both conventional and STE measures, as well as decreased right and left ventricular output. The right ventricular eccentricity index was higher in ECMO vs non-ECMO patients (2.2 vs 1.8, P = .02). There was no difference in pulmonary hypertension between CDH groups. CONCLUSIONS: Need for ECMO was associated with decreased left and right ventricular function, as assessed by standard and STE measures. There was no difference in pulmonary hypertension between non ECMO and ECMO patients. Abnormal cardiac function may explain nonresponse to pulmonary vasodilators in patients with CDH. Management strategies to improve cardiac function may reduce the need for ECMO in newborns with CDH.
Assuntos
Ecocardiografia , Oxigenação por Membrana Extracorpórea , Ventrículos do Coração/fisiopatologia , Hérnias Diafragmáticas Congênitas/terapia , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Direita/etiologia , Feminino , Testes de Função Cardíaca , Ventrículos do Coração/diagnóstico por imagem , Hérnias Diafragmáticas Congênitas/complicações , Hérnias Diafragmáticas Congênitas/fisiopatologia , Humanos , Recém-Nascido , Masculino , Estudos Retrospectivos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/fisiopatologiaRESUMO
AIM: The endothelium, mainly via nitric oxide (NO) release, adjusts the coronary flow. Cardiac function is closely linked to blood flow; thus, we tested the hypothesis that NO modulation in coronary arteries could be differentially adjusted after myocardial infarction (MI) in the presence or absence of heart failure (HF). METHODS AND RESULTS: Four weeks after coronary occlusion, the infarcted rats were subdivided into rats without (MI) or with HF signs according to haemodynamic parameters. The septal coronary arteries were subsequently used to perform functional and molecular experiments. Acetylcholine (ACh)-induced relaxation was decreased in the coronary arteries following HF, whereas it was enhanced in the arteries of the MI compared with those of SHAM-operated (SO) rats. The relaxation induced by the NO donor was similar among the groups. NO production, which was evaluated by 4,5-diaminofluorescein diacetate, was reduced in the coronary arteries of the HF group and increased in the arteries with MI after ACh-induced stimulation. HF coronary arteries exhibited oxidative stress, which was evaluated via ethidium bromide-positive nuclei, whereas it was decreased in MI. To evaluate the mechanisms involved in the enhanced ACh-induced relaxation in the arteries following MI, certain septal coronary arteries were pre-incubated with L-NAME (a nonselective NO synthase (NOS) inhibitor), 7-NI (a selective neuronal NOS (nNOS) inhibitor) or LY294002 (a PI3-kinase inhibitor). L-NAME and LY294002 reduced ACh-induced relaxation in the MI and SO rats; however, these effects were greater in the MI arteries. 7-NI reduced only the ACh-relaxation in MI. In addition, the eNOS, nNOS, Akt, and superoxide dismutase isoform protein expressions were greater in the coronary arteries of the MI than in those of the SO groups. CONCLUSION: Our data suggested that endothelial function was closely related to cardiac function after coronary occlusion. The coronary arteries from the HF rats exhibited reduced NO bioavailability, whereas the MI rats exhibited increased NO bioavailability because of increased eNOS/nNOS/PI3-kinase/Akt pathway and a reduction in ROS generation. These results suggest that enhanced NO modulation can prevent the onset of HF.