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 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.- Cardiovascular autonomic dysfunction in non-obese diabetic mice(2013) MORAES, Oscar A.; COLUCCI, Juliana A.; SOUZA, Leandro E.; SCAPINI, Katia B.; MORAES-SILVA, Ivana C.; MOSTARDA, Cristiano; ANGELIS, Katia De; CASARINI, Dulce E.; IRIGOYEN, Maria ClaudiaIt is known that diabetes is associated with autonomic dysfunction; however, data about autonomic function in non-obese diabetic mice (NOD) remain scarce. We evaluated the autonomic profile of NOD mice. Female mice, 24-28 week old, were divided in two groups: NOD (n = 6) and control (n = 6, Swiss mice). NOD mice with glycemia >= 300 mg/dl were used. Heart rate variability (HRV) and arterial pressure variability (APV) in time and frequency domains, symbolic analysis of heart rate (HR) and baroreflex sensitivity were evaluated. HR and arterial pressure (AP) were similar between the groups; however, HRV (total variance of RR interval: NOD = 21.07 +/- 3.75 vs. C = 42.02 +/- 6.54 ms(2)) and the vagal modulation index RMSSD were lower in NOD group (4.01 +/- 032 vs. 8.28 +/- 0.97 ms). Moreover, the absolute and normalized low-frequency (LF) components were also enhanced in NOD (normalized = 61.0 +/- 4.0%) as compared to control mice (normalized = 20.0 +/- 4.0%). Both the absolute and normalized high-frequency (HF) components were lower in NOD (normalized = 39.0 +/- 4.0%) when compared to the control group (normalized = 80.0 +/- 4.0). In the symbolic analysis the 0V pattern, an indication of sympathetic activity, was higher in NOD and 2LV pattern, an indication of parasympathetic activity, was lower in the NOD than in the control group. Both bradycardic and tachycardic responses were decreased in NOD (3.01 +/- 0.72 vs. 4.54 +/- 0.36 bpm/mm Hg and 2.49 +/- 031 vs. C = 3.43 +/- 033 bpm/mm Hg) when compared to the control group. Correlation analysis showed negative correlations between vagal indexes (RMSSD, %HF and 2LV) and glycemic levels. In conclusion, NOD mice develop severe diabetes correlated with autonomic dysfunction.
- Interval and continuous aerobic exercise training similarly increase cardiac function and autonomic modulation in infarcted mice (vol 13, pg 257, 2017)(2017) ABAD, Cesar Cavinato Cal; NASCIMENTO, Ademir Manuel do; SOUZA, Leandro Eziquiel de; FIGUEROA, Diego; RAMONA, Pamella; SARTORI, Michele; SCAPINI, Katia B.; ALBUQUERQUE, Oscar; MORAES-SILVA, Ivana Cinthya; COELHO-JUNIOR, Helio Jose; RODRIGUES, Bruno; MOSTARDA, Cristiano Teixeira; ANGELIS, Katia De; IRIGOYEN, Maria Claudia
conferenceObject Interval training program improves cardiac function and physical performance in heart failure mice(2013) ABAD, Cesar Cavinato Cal; MOSTARDA, Cristiano Teixeira; NASCIMENTO, Ademir Manuel; SANTOS, Mirailton Alves dos; SOUZA, Leandro Eziquiel; FIGUEROA, Diego M. T.; SANTOS, Fernando; SOUZA, Pamella Ramona Moraes de; ANGELIS, Katia De; IRIGOYEN, Maria ClaudiaThis study was designed to verify the effect of an eight week interval training program (IT) in systolic and diastolic functions and physical performance in heart failure mice (C57B16, n=24). The animals were divided in three groups: 1) Intact sedentary (C), 2) infarcted sedentary (MI-s); and 3) infarcted trained (MI-i). At the begining (M1) and at the end of IT (M2), time of maximal running performance (Tvmáx) was quantified. The ejection fraction (EF), shortening fraction (SF) and isovolumetric relaxation time (IVRT) were accessed by echocardiography in M2. At 60 days after coronary artery occlusion the IT was started (4min at 80% Vmáx x 4min at 40% Vmáx during 60min). The results are presented in mean and SEM. Myocardial infarction area was not different between groups in both evaluation time (M1vsM2). The EF and SF in MI-s were lower than C (44±3.7vs58±3.0% and 22±2vs31±2%, respectively; p≤0.05) but similar between MI-i and C (56±5vs58±3% and 25±3vs31±2%, respectively). The IVRT was higher (p≤0.05) in MI-s (25.6±4ms) than C (13±1ms) while similar in MI-i (15±0.8ms) and C. At the M1 both MI-s and MI-i Tvmáx decreased in comparison with C (620±16 and 644±28vs840±17s, respectively). At the M2, Tvmáx delta percent was higher in MI-i than MI-s (64±8vs15±6%, respectively; p≤0.05) and C (0.53±3%). The results suggest that IT improves cardiac function and physical performance in heart failure mice.- Cholinergic stimulation with pyridostigmine improves autonomic function in infarcted rats(2013) FUENTE, Raquel N. de La; RODRIGUES, Bruno; MORAES-SILVA, Ivana C.; SOUZA, Leandro E.; SIRVENTE, Raquel; MOSTARDA, Cristiano; ANGELIS, Katia De; SOARES, Pedro P.; LACCHINI, Silvia; CONSOLIM-COLOMBO, Fernanda; IRIGOYEN, Maria-Claudia1. In the present study we evaluated the effects of shortterm pyridostigmine bromide (0.14 mg/mL) treatment started early after myocardial infarction (MI) on left ventricular (LV) and autonomic functions in rats. 2. Male Wistar rats were divided into control, pyridostigmine, infarcted and infarcted + pyridostigmine-treated groups. Pyridostigmine was administered in the drinking water, starting immediately after MI or sham operation, for 11 days. Left ventricular function was evaluated indirectly by echocardiography and directly by LV catheterization. Cardiovascular autonomic control was evaluated by baroreflex sensitivity (BRS), heart rate variability (HRV) and pharmacological blockade. All evaluations started after 7 days pyridostigmine treatment and were finalized after 11 days treatment. 3. Pyridostigmine prevented the impairment of + dP/dT and reduced the MI area in infarcted + pyridostigmine compared with infarcted rats (7 +/- 3% vs 17 +/- 4%, respectively). Mean blood pressure was restored in infarcted + pyridostigmine compared with infarcted rats (103 +/- 3 vs 94 +/- 3 mmHg, respectively). In addition, compared with the infarcted group, pyridostigmine improved BRS, as evaluated by tachycardic (1.6 +/- 0.2 vs 2.5 +/- 0.2 b. p. m./mmHg, respectively) and bradycardic (-0.42 +/- 0.01 vs -1.9 +/- 0.1 b. p. m./mmHg) responses, and reduced the low frequency/high frequency ratio of HRV (0.81 +/- 0.11 vs 0.24 +/- 0.14, respectively). These improvements are probably associated with increased vagal tone and reduced sympathetic tone in infarcted + pyridostigmine compared with infarcted rats. 4. In conclusion, the data suggest that short-term pyridostigmine treatment started early after MI can improve BRS, HRV and parasympathetic and sympathetic tone in experimental rats. These data may have potential clinical implications because autonomic markers have prognostic significance after MI.