Time filter

Source Type

Cipriano G.,University of Brasilia | Neder J.A.,Queens University | Umpierre D.,Exercise Pathophysiology Research Laboratory and Cardiology Division | Arena R.,University of Illinois at Chicago | And 5 more authors.
Journal of Applied Physiology | Year: 2014

We tested the hypothesis that transcutaneous electrical nerve stimulation (TENS) over the stellate ganglion region would reduce sympathetic overstimulation and improve femoral blood flow (FBF) after coronary artery bypass graft surgery. Thirty-eight patients (20 men, 24 New York Heart Association class III-IV) were randomized to 5-day postoperative TENS (n = 20; 4 times/day; 30 min/session) or sham TENS (n = 18) applied to the posterior cervical region (C7-T4). Sympathetic nervous system was stimulated by the cold pressor test, with FBF being measured by ultrasound Doppler. Femoral vascular conductance (FVC) was calculated as FBF/mean arterial pressure (MAP). Six-min walking distance established patients' functional capacity. Before and after the intervention periods, pain scores, opiate requirements, and circulating β-endorphin levels were determined. As expected, preoperative MAP increased and FBF and FVC decreased during the cold pressor test. Sham TENS had no significant effect on these variables (P > 0.05). In contrast, MAP decreased in the TENS group (125 ± 12 vs. 112 ± 10 mmHg). This finding, in association with a consistent increase in FBF (95 ± 5 vs. 145 ± 14 ml/min), led to significant improvements in FVC (P < 0.01). Moreover, 6-min walking distance improved only with TENS (postsurgery-presurgery = 35 ± 12 vs. 6 ± 10 m; P < 0.01). TENS was associated with lesser postoperative pain and opiate requirements but greater circulating β-endorphin levels (P < 0.05). In conclusion, stellate ganglion TENS after coronary artery bypass graft surgery positively impacted on limb blood flow during a sympathetic stimulation maneuver, a beneficial effect associated with improved clinical and functional outcomes. © 2014 the American Physiological Society. Source

Jeronimo F.S.,Bom Pastor Health Center Unit | Alves G.N.,Exercise Pathophysiology Research Laboratory and Cardiology Division | Cipriano G.,University of Brasilia | Vieira P.J.C.,Intensive Care Unit | And 3 more authors.
Brazilian Journal of Infectious Diseases | Year: 2015

Background: the impact of human immunodeficiency virus type 1 (HIV-1) on lung function is well known and associated with a reduction in pulmonary ventilation. Moreover, the use of highly active antiretroviral therapy has been associated with mitochondrial dysfunction and decreased muscle strength. However, there is scarce information about the factors associated with inspiratory muscle weakness in these patients. Objective: the purpose of the present study was to investigate the factors associated with inspiratory muscle weakness in patients with HIV-1. Methods: two-hundred fifty seven patients with HIV-1 were screened and categorized into two groups: (1) IMW+ (n=142) and (2) IMW- (n=115). Lung function (FEV1, FVC and FEV1/FVC), maximum inspiratory pressure, distance on the six-minute walk test and CD4 cell count were assessed. Results: the mean duration of HIV infection was similar in the two groups. The following variables were significantly different between groups: mean duration of highly active antiretroviral therapy (81±12 in IMW+ versus 38±13 months in IMW-; p=0.01), and CD4 cell count (327±88 in IMW+ versus 637±97cells/mm3 in IMW-; p=0.02). IMW+ presented reduced lung function (FEV1, FVC, FEV1/FVC). Conclusion: patients with IMW+ had lower distance on the six-minute walk test in comparison to the IMW- group. The duration of highly active antiretroviral therapy, distance traveled on the 6MWT and CD4 count were determinants of IMW in patients with HIV. © 2015. Source

Mandic S.,Palo Alto Veterans Affairs Medical Center | Mandic S.,Stanford University | Mandic S.,University of Otago | Fonda H.,Palo Alto Veterans Affairs Medical Center | And 11 more authors.
Physician and Sportsmedicine | Year: 2010

Background: Broad criteria for classifying an electrocardiogram (ECG) as abnormal and requiring additional testing prior to participating in competitive athletics have been recommended for the preparticipation examination (PPE) of athletes. Because these criteria have not considered gender differences, we examined the effect of gender on the computerized ECG measurements obtained on Stanford student athletes. Currently available computer programs require a basis for "normal" in athletes of both genders to provide reliable interpretation. Methods: During the 2007 PPE, computerized ECGs were recorded and analyzed on 658 athletes (54% male; mean age, 19 ± 1 years) representing 22 sports. Electrocardiogram measurements included intervals and durations in all 12 leads to calculate 12-lead voltage sums, QRS amplitude and QRS area, spatial vector length (SVL), and the sum of the R wave in V 5 and S wave in V2 (RSsum). Results: By computer analysis, male athletes had significantly greater QRS duration, PR interval, Q-wave duration, J-point amplitude, and T-wave amplitude, and shorter QTc interval compared with female athletes (all P < 0.05). All ECG indicators of left ventricular electrical activity were significantly greater in males. Although gender was consistently associated with indices of atrial and ventricular electrical activity in multivariable analysis, ECG measurements correlated poorly with body dimensions. Conclusion: Significant gender differences exist in ECG measurements of college athletes that are not explained by differences in body size. Our tables of "normal" computerized gender-specific measurements can facilitate the development of automated ECG interpretation for screening young athletes. © The Physician and Sportsmedicine. Source

Santos F.V.,Federal University of Sao Paulo | Chiappa G.R.,Exercise Pathophysiology Research Laboratory and Cardiology Division | Vieira P.J.C.,Exercise Pathophysiology Research Laboratory and Cardiology Division | Umpierre D.,Exercise Pathophysiology Research Laboratory and Cardiology Division | And 2 more authors.
Brazilian Journal of Physical Therapy | Year: 2013

Background: Interferential electrical stimulation (IES), which may be linked to greater penetration of deep tissue, may restore blood flow by sympathetic nervous modulation; however, studies have found no association between the frequency and duration of the application and blood flow. We hypothesized that 30 min of IES applied to the ganglion stellate region might improve blood flow redistribution. Objectives: The purpose of this study was to determine the effect of IES on metaboreflex activation in healthy individuals. Method: Interferential electrical stimulation or a placebo stimulus (same protocol without electrical output) was applied to the stellate ganglion region in eleven healthy subjects (age 25±1.3 years) prior to exercise. Mean blood pressure (MBP), heart rate (HR), calf blood flow (CBF) and calf vascular resistance (CVR) were measured throughout exercise protocols (submaximal static handgrip exercise) and with recovery periods with or without postexercise circulatory occlusion (PECO+ and PECO -, respectively). Muscle metaboreflex control of calf vascular resistance was estimated by subtracting the area under the curve when circulation was occluded from the area under the curve from the AUC without circulatory occlusion. Results: At peak exercise, increases in mean blood pressure were attenuated by IES (p<0.05), and the effect persisted under both the PECO+ and PECO-treatments. IES promoted higher CBF and lower CVR during exercise and recovery. Likewise, IES induced a reduction in the estimated muscle metaboreflex control (placebo, 21±5 units vs. IES, 6±3, p<0.01). Conclusion: Acute application of IES prior to exercise attenuates the increase in blood pressure and vasoconstriction during exercise and metaboreflex activation in healthy subjects. Source

Paolillo F.R.,University of Sao Paulo | Ross A.,University of Illinois at Chicago | Dutra D.B.,Federal University of Sao Carlos | De Cassia Marqueti Durigan R.,University of Brasilia | And 6 more authors.
Lasers in Surgery and Medicine | Year: 2014

Background and Objective: Phototherapy plus dynamic exercise can enhance physical performance and improve health. The aim of our study was to evaluate the effect of low-level laser therapy (LLLT) associated with high intensity resistance training (HIT) on cardiac autonomic and muscle metabolic responses in rats.Study Design/Materials and Methods: Forty Wistar rats were randomized into 4 groups: sedentary control (CG), HIT, LLLT and HIT+LLLT. HIT was performed 3 times/week for 8 weeks with loads attached to the tail of the animal. The load was gradually increased by 10% of body mass until reaching a maximal overload. For LLLT, irradiation parameters applied to the tibialis anterior (TA) muscle were as follows: infrared laser (780 nm), power of 15mW for 10 seconds, leading to an irradiance of 37.5mW/cm2, energy of 0.15 J per point and fluency of 3.8 J/cm2. Blood lactate (BL), matrix metalloproteinase gelatinase A (MMP<-2) gene expression and heart rate variability (HRV) indices were performed.Results: BL significantly increased after 8-weeks for HIT, LLLT and HIT+LLLT groups. However, peak lactate when normalized by maximal load was significantly reduced for both HIT and HIT+LLLT groups (P<0.05). MMP<-2 in the active form was significantly increased after HIT, LLLT and HIT+LLLT compared tom the CG (P<0.05). There was a significant reduction in low frequency [LF (ms2)] and increase in high frequency [HF (un)] and HF (ms2)] for the HIT, LLLT and HIT+LLLT groups compared with the CG (P<0.05). However, the LF/ HFratio was further reduced in the LLLT and HIT+LLLT groups compared to the CG and HIT group (P<0.05).Conclusion: These results provide evidence for the positive benefits of LLLT and HIT with respect to enhanced muscle metabolic and cardiac autonomic function in Wistar rats. Lasers Surg. © 2014 Wiley Periodicals, Inc. Source

Discover hidden collaborations