LEANDRO EZIQUIEL DE SOUZA
Índice h a partir de 2011
7
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
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conferenceObject Impact of sympathectomy upon myocardium(2019) PESSOA, F. Fernanda; JORDAO, M. R.; FONSECA, K. C. B.; ZANONI, F.; SALEMI, V. M. C.; RIBEIRO, O. N.; SOUZA, L. E.; FERNANDES, F.; IRIGOYEN, M. C.; MOREIRA, L. F. P.; MADY, C.; RAMIRES, F. J. A.conferenceObject Baroreflex and cardiac dysfunctions evaluated by transesophageal echocardiography, baroreflex sensitivity, autonomic control and invasive measurements in rats submitted to sinoaortic denervation(2012) SIRVENTE, R. A.; IRIGOYEN, M. C.; SOUZA, L.; MOSTARDA, C.; FUENTE, R. La; CANDIDO, G.; SOUZA, P.; MEDEIROS, A.; MADY, C.; SALEMI, V. M. C.Purpose: Sympathetic hyperactivity commonly seems to be related to cardiac dysfunction and baro and chemoreflexes impairment in hypertension. However, myocardial function has not been evaluated regarding the association of hypertension and baroreflex dysfunction using transesophageal echocardiography. Methods: Exercise test (ET), baroreflex sensitivity, cardiovascular autonomic control, transthoracic and transesophageal echocardiography using intracardiac echocardiographic catheter (AcuNav, Siemens, Mountain View, CA, USA), and invasively biventricular end-diastolic pressures (EDP) were evaluated in rats 10 weeks after sinoaortic denervation (SAD). The rats (n=32) were divided in 4 groups: 16 Wistar (W) with (n=8) or without SAD (n=8) and 16 spontaneously hypertensive rats (SHR) with (n=8) or without SAD (n=8). Results: Blood pressure (BP) and heart rate (HR) did not show any change between the groups SAD and without SAD, although, SHR showed higher BP levels in comparison to W. BP variability was increased in SHR groups compared to W. After SAD, BP variability increased in all groups compared to W (W: 15 mmHg2; *DSA: 49 mmHg2; *SHR: 60 mmHg2; *SHR-SAD:137 mmHg2, *p<0.05 vs. W). Exercise tests results showed that SHR had better functional capacity compared to SAD and SHRSAD (W: 1.16m/s; DSA: 0.9m/s; *SHR: 1.46; SHR-DSA: 1.02, *p<0.05 vs. SAD and SHRSAD). Left ventricular concentric hypertrophy, segmental systolic dysfunction and global diastolic LV dysfunction, segmental and global systolic dysfunction, and global diastolic RV dysfunction, indirect signals of pulmonary arterial hypertension were shown by echocardiography, mostly evident in SHRSAD. The RV-EDP increased in all groups compared to W(W:3±0.39mmHg, *SAD:4.7±0.52mmHg, *SHR: 6.6±1.1mmHg, *SHRSAD:7.8±0.87mmHg, *p<0.05 vs. W), and LV-EDP increased in SHR and SHRSAD groups compared to W, and in SHRSAD compared to SAD (W: 5,83±0,19 mmHg,SAD: 8.98±1.2 mmHg, *SHR: 12.51±4.73 mmHg, *#SHRSAD: 14.57±2.52mmHg, *p<0.05vs.W,#p<0.05 vs. DSA). There was a relation between invasive or noninvasive measurements of RV showing good accuracy of echocardiographic measurements. Conclusions: Our results suggest that baroreflex dysfunction impaired biventricular function. Moreover, the findings of RV dysfunction indicate that SAD may lead to increased pulmonary artery pressure, supporting a role for baroreflex dysfunction in the pathogenesis of the hypertensive cardiac disease.- Effects of sympathectomy on myocardium remodeling and function(2021) JORDAO, Mauricio Rodrigues; PESSOA, Fernanda G.; FONSECA, Keila C. B.; ZANONI, Fernando; SALEMI, Vera M. C.; SOUZA, Leandro E.; RIBEIRO, Orlando N.; FERNANDES, Fabio; IRIGOYEN, Maria Claudia; MOREIRA, Luiz Felipe P.; MADY, Charles; RAMIRES, Felix Jose AlvarezOBJECTIVES: To evaluate the effects of sympathectomy on the myocardium in an experimental model. METHODS: The study evaluated three groups of male Wistar rats: control (CT; n=15), left unilateral sympathectomy (UNI; n=15), and bilateral sympathectomy (BIL; n=31). Sympathectomy was performed by injection of absolute alcohol into the space of the spinous process of the C7 vertebra. After 6 weeks, we assessed the chronotropic properties at rest and stress, cardiovascular autonomic modulation, myocardial and peripheral catecholamines, and beta-adrenergic receptors in the myocardium. The treadmill test consisted of an escalated protocol with a velocity increment until the maximal velocity tolerated by the animal was reached. RESULTS: The bilateral group had higher levels of peripheral catecholamines, and consequently, a higher heart rate (HR) and blood pressure levels. This suggests that the activation of a compensatory pathway in this group may have deleterious effects. The BIL group had basal tachycardia immediately before the exercise test and increased tachycardia at peak exercise (p<0.01); the blood pressure had the same pattern (p=0.0365). The variables related to autonomic modulation were not significantly different between groups, with the exception of the high frequency (HF) variable, which showed significant differences in CT vs UNI. There was no significant difference in beta receptor expression between groups. There was a higher concentration of peripheral norepinephrine in the BIL group (p=0.0001), and no significant difference in myocardial norepinephrine (p=0.09). CONCLUSION: These findings suggest that an extra cardiac compensatory pathway increases the sympathetic tonus and maintains a higher HR and higher levels of peripheral catecholamines in the procedure groups. The increase in HF activity can be interpreted as an attempt to increase the parasympathetic tonus to balance the greater sympathetic activity.