ANA MARIA FONSECA WANDERLEY BRAGA
Índice h a partir de 2011
6
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina - Médico
4 resultados
Resultados de Busca
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- Obstructive Sleep Apnea Impairs Postexercise Sympathovagal Balance in Patients with Metabolic Syndrome(2015) CEPEDA, Felipe X.; TOSCHI-DIAS, Edgar; MAKI-NUNES, Cristiane; RONDON, Maria Urbana P. B.; ALVES, Maria Janieire N. N.; BRAGA, Ana Maria F. W.; MARTINEZ, Daniel G.; DRAGER, Luciano F.; LORENZI-FILHO, Geraldo; NEGRAO, Carlos E.; TROMBETTA, Ivani C.Study Objectives: The attenuation of heart rate recovery after maximal exercise (Delta HRR) is independently impaired by obstructive sleep apnea (OSA) and metabolic syndrome (MetS). Therefore, we tested the hypotheses: (1) MetS + OSA restrains Delta HRR; and (2) Sympathetic hyperactivation is involved in this impairment. Design: Cross-sectional study. Participants: We studied 60 outpatients in whom MetS had been newly diagnosed (ATP III), divided according to apnea-hypopnea index (AHI) >= 15 events/h in MetS + OSA (n = 30, 49 +/- 1.7 y) and AHI < 15 events/h in MetS - OSA (n = 30, 46 +/- 1.4 y). Normal age-matched healthy control subjects (C) without MetS and OSA were also enrolled (n = 16, 46 +/- 1.7 y). Interventions: Polysomnography, microneurography, cardiopulmonary exercise test. Measurements and Results: We evaluated OSA (AHI - polysomnography), muscle sympathetic nerve activity (MSNA - microneurography) and cardiac autonomic activity (LF = low frequency, HF = high frequency, LF/HF = sympathovagal balance) based on spectral analysis of heart rate (HR) variability. Delta HRR was calculated (peak HR minus HR at first, second, and fourth minute of recovery) after cardiopulmonary exercise test. MetS + OSA had higher MSNA and LF, and lower HF than MetS - OSA and C. Similar impairment occurred in MetS - OSA versus C (interaction, P < 0.01). MetS + OSA had attenuated Delta HRR at first, second, and at fourth minute than did C, and attenuated Delta HRR at fourth minute than did MetS - OSA (interaction, P < 0.001). Compared with C, MetS - OSA had attenuated Delta HRR at second and fourth min (interaction, P < 0.001). Further analysis showed association of the Delta HRR (first, second, and fourth minute) and AHI, MSNA, LF and HF components (P < 0.05 for all associations). Conclusions: The attenuation of heart rate recovery after maximal exercise is impaired to a greater degree where metabolic syndrome (MetS) is associated with moderate to severe obstructive sleep apnea (OSA) than by MetS with no or mild or no OSA. This is at least partly explained by sympathetic hyperactivity.
- Exaggerated Exercise Blood Pressure as a Marker of Baroreflex Dysfunction in Normotensive Metabolic Syndrome Patients(2021) DUTRA-MARQUES, Akothirene C.; RODRIGUES, Sara; CEPEDA, Felipe X.; TOSCHI-DIAS, Edgar; RONDON, Eduardo; CARVALHO, Jefferson C.; ALVES, Maria Janieire N. N.; BRAGA, Ana Maria F. W.; RONDON, Maria Urbana P. B.; TROMBETTA, Ivani C.Introduction Exaggerated blood pressure response to exercise (EEBP = SBP >= 190 mmHg for women and >= 210 mmHg for men) during cardiopulmonary exercise test (CPET) is a predictor of cardiovascular risk. Sympathetic hyperactivation and decreased baroreflex sensitivity (BRS) seem to be involved in the progression of metabolic syndrome (MetS) to cardiovascular disease. Objective To test the hypotheses: (1) MetS patients within normal clinical blood pressure (BP) may present EEBP response to maximal exercise and (2) increased muscle sympathetic nerve activity (MSNA) and reduced BRS are associated with this impairment. Methods We selected MetS (ATP III) patients with normal BP (MetS_NT, n = 27, 59.3% males, 46.1 +/- 7.2 years) and a control group without MetS (C, n = 19, 48.4 +/- 7.4 years). We evaluated BRS for increases (BRS+) and decreases (BRS-) in spontaneous BP and HR fluctuations, MSNA (microneurography), BP from ambulatory blood pressure monitoring (ABPM), and auscultatory BP during CPET. Results Normotensive MetS (MetS_NT) had higher body mass index and impairment in all MetS risk factors when compared to the C group. MetS_NT had higher peak systolic BP (SBP) (195 +/- 17 vs. 177 +/- 24 mmHg, P = 0.007) and diastolic BP (91 +/- 11 vs. 79 +/- 10 mmHg, P = 0.001) during CPET than C. Additionally, we found that MetS patients with normal BP had lower spontaneous BRS- (9.6 +/- 3.3 vs. 12.2 +/- 4.9 ms/mmHg, P = 0.044) and higher levels of MSNA (29 +/- 6 vs. 18 +/- 4 bursts/min, P < 0.001) compared to C. Interestingly, 10 out of 27 MetS_NT (37%) showed EEBP (MetS_NT+), whereas 2 out of 19 C (10.5%) presented (P = 0.044). The subgroup of MetS_NT with EEBP (MetS_NT+, n = 10) had similar MSNA (P = 0.437), but lower BRS+ (P = 0.039) and BRS- (P = 0.039) compared with the subgroup without EEBP (MetS_NT-, n = 17). Either office BP or BP from ABPM was similar between subgroups MetS_NT+ and MetS_NT-, regardless of EEBP response. In the MetS_NT+ subgroup, there was an association of peak SBP with BRS- (R = -0.70; P = 0.02), triglycerides with peak SBP during CPET (R = 0.66; P = 0.039), and of triglycerides with BRS- (R = 0.71; P = 0.022). Conclusion Normotensive MetS patients already presented higher peak systolic and diastolic BP during maximal exercise, in addition to sympathetic hyperactivation and decreased baroreflex sensitivity. The EEBP in MetS_NT with apparent well-controlled BP may indicate a potential depressed neural baroreflex function, predisposing these patients to increased cardiovascular risk.
- Obstructive Sleep Apnea is Associated with Increased Chemoreflex Sensitivity in Patients with Metabolic Syndrome(2013) TROMBETTA, Ivani C.; MAKI-NUNES, Cristiane; TOSCHI-DIAS, Edgar; ALVES, Maria-Janieire N. N.; RONDON, Maria Urbana P. B.; CEPEDA, Felipe X.; DRAGER, Luciano F.; BRAGA, Ana Maria F. W.; LORENZI-FILHO, Geraldo; NEGRAO, Carlos E.Study Objectives: Obstructive sleep apnea (OSA) is often observed in patients with metabolic syndrome (MetS). In addition, the association of MetS and OSA substantially increases sympathetic nerve activity. However, the mechanisms involved in sympathetic hyperactivation in patients with MetS + OSA remain to be clarified. We tested the hypothesis that chemoreflex sensitivity is heightened in patients with MetS and OSA. Design: Prospective clinical study. Participants: Forty-six patients in whom MetS was newly diagnosed (ATP-III) were allocated into: (1) MetS + OSA (n = 24, 48 +/- 1.8 yr); and (2) MetS -OSA (n = 22, 44 +/- 1.7 yr). Eleven normal control subjects were also studied (C, 47 +/- 2.3 yr). Measurements: OSA was defined as an apnea-hypopnea index >= 15 events/hr (polysomnography). Muscle sympathetic nerve activity (MSNA) was measured by microneurography technique. Peripheral chemoreflex sensitivity was assessed by inhalation of 10% oxygen and 90% nitrogen (carbon dioxide titrated), and central chemoreflex sensitivity by 7% carbon dioxide and 93% oxygen. Results: Physical characteristics and MetS measures were similar between MetS + OSA and MetS - OSA. MSNA was higher in MetS + OSA patients compared with MetS - OSA and C (33 +/- 1.3 versus 28 +/- 1.2 and 18 +/- 2.2 bursts/min, P < 0.05). Isocapnic hypoxia caused a greater increase in MSNA in MetS + OSA than MetS -OSA and C (P = 0.03). MSNA in response to hyperoxic hypercapnia was greater in MetS + OSA compared with C (P = 0.005). Further analysis showed a significant association between baseline MSNA and peripheral (P < 0.01) and central (P < 0.01) chemoreflex sensitivity. Min ventilation in response to hyperoxic hypercapnia was greater in MetS + OSA compared with C (P = 0.001). Conclusion: OSA increases sympathetic peripheral and central chemoreflex response in patients with MetS, which seems to explain, at least in part, the increase in sympathetic nerve activity in these patients. In addition, OSA increases ventilatory central chemoreflex response in patients with MetS.
- Oscillatory Pattern of Sympathetic Nerve Bursts Is Associated With Baroreflex Function in Heart Failure Patients With Reduced Ejection Fraction(2021) TOSCHI-DIAS, Edgar; MONTANO, Nicola; TOBALDINI, Eleonora; TREVIZAN, Patricia F.; V, Raphaela Groehs; ANTUNES-CORREA, Ligia M.; NOBRE, Thais S.; LOBO, Denise M.; SALES, Allan R. K.; UENO-PARDI, Linda M.; MATOS, Luciana D. N. J. de; OLIVEIRA, Patricia A.; BRAGA, Ana Maria F. W.; ALVES, Maria Janieire N. N.; NEGRAO, Carlos E.; RONDON, Maria Urbana P. B.Sympathetic hyperactivation and baroreflex dysfunction are hallmarks of heart failure with reduced ejection fraction (HFrEF). However, it is unknown whether the progressive loss of phasic activity of sympathetic nerve bursts is associated with baroreflex dysfunction in HFrEF patients. Therefore, we investigated the association between the oscillatory pattern of muscle sympathetic nerve activity (LFMSNA/HFMSNA) and the gain and coupling of the sympathetic baroreflex function in HFrEF patients. In a sample of 139 HFrEF patients, two groups were selected according to the level of LFMSNA/HFMSNA index: (1) Lower LFMSNA/HFMSNA (lower terciles, n = 46, aged 53 +/- 1 y) and (2) Higher LFMSNA/HFMSNA (upper terciles, n = 47, aged 52 +/- 2 y). Heart rate (ECG), arterial pressure (oscillometric method), and muscle sympathetic nerve activity (microneurography) were recorded for 10 min in patients while resting. Spectral analysis of muscle sympathetic nerve activity was conducted to assess the LFMSNA/HFMSNA, and cross-spectral analysis between diastolic arterial pressure, and muscle sympathetic nerve activity was conducted to assess the sympathetic baroreflex function. HFrEF patients with lower LFMSNA/HFMSNA had reduced left ventricular ejection fraction (26 +/- 1 vs. 29 +/- 1%, P = 0.03), gain (0.15 +/- 0.03 vs. 0.30 +/- 0.04 a.u./mmHg, P < 0.001) and coupling of sympathetic baroreflex function (0.26 +/- 0.03 vs. 0.56 +/- 0.04%, P < 0.001) and increased muscle sympathetic nerve activity (48 +/- 2 vs. 41 +/- 2 bursts/min, P < 0.01) and heart rate (71 +/- 2 vs. 61 & PLUSMN; 2 bpm, P < 0.001) compared with HFrEF patients with higher LFMSNA/HFMSNA. Further analysis showed an association between the LFMSNA/HFMSNA with coupling of sympathetic baroreflex function (R = 0.56, P < 0.001) and left ventricular ejection fraction (R = 0.23, P = 0.02). In conclusion, there is a direct association between LFMSNA/HFMSNA and sympathetic baroreflex function and muscle sympathetic nerve activity in HFrEF patients. This finding has clinical implications, because left ventricular ejection fraction is less in the HFrEF patients with lower LFMSNA/HFMSNA.