LEFT-VENTRICULAR MAXIMAL SYSTOLIC ELASTANCE CALCULATED BY A COMBINATION OF M-MODE ECHOCARDIOGRAPHY AND STANDARD MANOMETRY

1. A method for obtaining the end-systolic left ventricular (LV) pressure-diameter and stress-diameter relationships in man was critically analyzed.2. Pressure-diameter and stress-diameter relationships were determined throughout the cardiac cycle by combining standard LV manometry with M-mode echocardiography. Nine adult patients with heart disease and without heart failure were studied during intracardiac catheterization under three different conditions of arterial pressure, i.e., basal (B) condition (mean +/- SD systolic pressure, 102 +/- 10 mmHg) and two stable states of arterial hypertension (H(I), 121 +/- 12 mmHg; H(II), 147 +/- 17 mmHg) induced by venous infusion of phenylephrine after parasympathetic autonomic blockade with 0.04 mg/kg atropine.3. Significant reflex heart rate variation with arterial hypertension was observed (B, 115 +/- 20 bpm; H(I), 103 +/- 14 bpm; H(II), 101 +/- 13 bpm) in spite of the parasympathetic blockade with atropine. The linear end-systolic pressure-diameter and stress-diameter relationships ranged from 53.0 to 160.0 mmHg/cm and from 97.0 to 195.0 g/cm3, respectively.4. The end-systolic LV pressure-diameter and stress-diameter relationship lines presented high and variable slopes. The slopes, which are indicators of myocardial contractility, are susceptible to modifications by small deviations in the measurement of the ventricular diameter or by delay in the pressure curve recording.

Influencia da elevacao sustentada da pressao arterial sobre a dP/dt do ventriculo esquerdo mantendo-se constante a pressao diastolica do ventriculo esquerdo

Purpose - To evaluate the influence of sustained elevations of arterial pressure on dP/dt values, which the left ventricular end diastolic pressure was kept constant. Methods - Thirteen anesthetized dogs, mechanically ventilated and submitted to thoracotomy and pharmacological autonomic block (atropine - 0.5 mg/kg IV + oxprenolol - 3 mg/kg IV) were studied. The arterial pressure elevation was obtained by mechanical constriction of the descending thoracic aorta. Analyses were made in control (C) situation and after two successives increments of arterial pressure, sustained for 10min, called hypertension 1 (H1) and hypertension 2 (H2), respectively. The end diastolic left ventricular pressure was kept constant by utilization of a perfusion system connected to the left atria. Results - Heart rate did not change (C: 125 ± 13.9bpm; H1: 125 ± 13.5bpm; H2: 123 ± 14.1bpm; p > 0.05); the LVSP increased (C: 119 ± 8.1mmHg; H1: 142 ± 7.9mmHg; H2: 166 ± 7.7mmHg; p < 0.01); the AoDP increased (C: 89 ± 11.6mmHg; H1: 99 ± 9.5mmHg; H2: 120 ± 11.8mmHg; p < 0.01); the LVEDP (C: 6.2 ± 2.48mmHg; H1: 6.3 ± 2.43mmHg; H2: 6.1 ± 2.51mmHg; p > 0.05) and the dP/dt (C: 3068 ± 1057.1mmHg/s; 3112 ± 995.7mmHg/s; H2: 3086 ± 979.5mmHg/s; p > 0.05) did not change. Conclusion - dP/dt values are not influenced by a sustained elevation of arterial pressure, when the end diastolic left ventricular pressure is kept constant.

The effect of sets and repetitions of the spirometer by flow in cardiorespiratory parameters

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Associação do treinamento resistido e aeróbico em pacientes com doença pulmonar crônica

Introduction: The pulmonary rehabilitation (PR) is composed of aerobic and resisted exercises that improve the functional capacity to the exercise, life quality and decrease respiratory symptoms in subjects with chronic pulmonary disease. Objective: Assess the effects of a combined PR program in the cardiorespiratory function and peripheral muscle strength in subjects with chronic pulmonary disease. Method: Patients with chronic pulmonary disease were submitted to the PR program, which was developed on 24 sessions of 60 minutes (three times per week). The program was composed of aerobic exercises (two times per week) and resisted exercises (once a week). Before and after the PR the patients were submitted to manovacuometry in order to measure the maximum inspiratory pressure (MIP) and the maximum expiratory pressure (MEP), ventilometry, peek expiratory flow (PEF), six minute walking test (6MWT) and one maximum repetition (1RM). The data are presented in absolute frequency, percentage and mean±standard deviation. The t Student test was used to compare data before and after the PR and the ANOVA test to compare before, after and predicted distances in the 6MWT (p<0.05). Results: Seven patients were part of this study, 85.70% of women, 71.40% with pulmonary emphysema diagnosis. The mean age was 69.43±5.59 years old, the height was 1.61±0.07 m, the mean weight was 66.20±8.40 kg and the body mass index mean was 25.50±2.48 kg/m². From the variables assessed, the MEP increased from 79.71±13.69 to 84.42±12.83 cmH2O (p=0,03), the PEF increase from 255.71±66.3 to 320.00±93.63 l/min (p=0,03) and the distance in the 6MWT from 415.28±47.90 to 483,79±79,77 m (p=0,02). The load in the 1RM test in the reverse peck deck exercise (before - - 17.10±8.10kg; after – 210.40±9.00kg), knee in leg extension machine (before – 17.10±9.50kg; after – 26.40±13.10kg) and hip extensors (right before – 48.60±22.10kg; after – 62.90±19.30kg; and left before – 46.40±20.10kg; after – 62.10±18.20kg) increased significantly (p<0,05). Conclusion: After the PR program there was improvement in the expiratory muscular strength, in the lower limbs strength and in the functional capacity. Besides that, there was a reduction in the airflow obstruction of the subjects with chronic pulmonary disease.

Existe correlação entre força muscular com o teste de caminhada de seis minutos em idosos institucionalizados?

The six-minute walking test can be affected by several variables, among them, the respiratory and peripheral muscle strength. The objective of this study was to correlate the respiratory muscle strength (maximum inspiratory pressure – MIP; and maximum expiratory pressure – MEP) and the hand grip test (HGT)with the six minute walking test distance in institutionalized elderly. It was included in this study 9 institutionalized elderly with age over 70 years old, both gender, evaluated by means of manometer, dynamometry and six minute walking test. The data were correlated by using the Pearson’s correlation test and the Spearman correlation test. From the evaluated elderly, it was four men and five women, with mean age: 78.8±7.3 years old, MIP: 75.7±33.6 cmH2O, MEP: 62.4±25.0 cmH2O, HGT: 20.4±6.2 kgf (right member) and 20.7±6.8 kgf (left member) and the distance on six minute walking test: 238.5±99.0 meters. There was correlation between expiratory strength and hand grip of both members with the distance on the six minute walking test. It is possible to conclude that there are correlation between expiratory muscle strength with the hand grip test and the functional capacity in institucionalized elderly.

Existe correlação antre força muscular com teste de caminhada de seis minutos em idosos institucionalizados?

The six-minute walking test can be affected by several variables, among them, the respiratory and peripheral muscle strength. The objective of this study was to correlate the respiratory muscle strength (maximum inspiratory pressure – MIP; and maximum expiratory pressure – MEP) and the hand grip test (HGT)with the six minute walking test distance in institutionalized elderly. It was included in this study 9 institutionalized elderly with age over 70 years old, both gender, evaluated by means of manometer, dynamometry and six minute walking test. The data were correlated by using the Pearson’s correlation test and the Spearman correlation test. From the evaluated elderly, it was four men and five women, with mean age: 78.8±7.3 years old, MIP: 75.7±33.6 cmH2O, MEP: 62.4±25.0 cmH2O, HGT: 20.4±6.2 kgf (right member) and 20.7±6.8 kgf (left member) and the distance on six minute walking test: 238.5±99.0 meters. There was correlation between expiratory strength and hand grip of both members with the distance on the six minute walking test. It is possible to conclude that there are correlation between expiratory muscle strength with the hand grip test and the functional capacity in institucionalized elderly.

Função Pulmonar de pacientes submetidos a Cirurgia Bariátrica

Introduction: Obesity is a risk factor for postoperative pulmonary complications. Overweight can alter respiratory mechanics and decrease lung volumes and capacities. Bariatric surgery (BS) has been used as treatment for morbid obesity, but this surgery can lead to respiratory complications. Objective: To evaluate pulmonary function in morbid obese patients undergoing bariatric surgery. Methods: The patients were submitted to pulmonary function testing, including slow and forced vital capacity (SVC and FVC), forced expiratory volume in the first second (FEV1), Tiffenau index (FEV1/FVC), forced expiratory flow 25-75% (FEF25-75%) and maximal inspiratory and expiratory pressure (MIP and MEP). Descriptive analysis was performed. Results: We evaluated 18 patients, mean age of 37.33 ± 11.23 years, height 1.65 ± 0.09 m, weight 125.92 ± 25.24 kg and BMI 46.34 ± 9 20 kg/m2 , SVC 100.64 ± 22.91%, FVC 102.04 ± 21.82%, FEV1 104.85 ± 22.16%, FEV1 /FVC 83.54 ± 6.63% and FEF25-75% 84.47 ± 25.74%, 99.75 ± 24.55 for MIP and MEP 102.12 ± 25.06 cmH2O. Conclusion: The bariatric surgery candidates had normal values for manovacuometry and spirometry.

Preoperative therapy restores ventilatory parameters and reduces length of stay in patients undergoing myocardial revascularization

Introduction: The frequency of surgical procedures has increased steadily in recent decades, including the myocardial revascularization.Objectives: To demonstrate the importance of physiotherapy in the preoperative period of cardiac surgery in relation to the reduction of hospital stay, changes in lung volumes and respiratory muscle strength.Methods: We conducted a prospective study with patients undergoing myocardial revascularization, the Hospital das Clinicas da Universidade Estadual Paulista (UNESP)/Botucatu - SP. We evaluated 70 patients of both genders, aged between 40 and 75 years, subdivided into two groups: group I - 35 patients of both genders, who received a written protocol guidance, breathing exercises and respiratory muscle training in the preoperative period and group II - 35 patients of both genders, who received only orientation of the ward on the day of surgery. This study was approved by the Ethics Committee of UNESP /Botucatu - SP.Results: Maximal inspiratory pressure in third postoperative day and fifth postoperative day and significant difference between groups, being better for the intervention group. Expiratory pressure was significant in fifth postoperative day in the intervention group compared to controls. The difference of length of hospital stay in the postoperative was found between the groups with shorter hospital stay in the group receiving preoperative therapy.Conclusion: Physical therapy plays an important role in the preoperative period, so that individuals in the intervention group more readily restored the parameters evaluated before surgery, in addition, there was a decrease in the time of the postoperative hospital stay. Thus, it is thought the cost-effectiveness of a program of preoperative physiotherapy.

Analgesia controlada pelo paciente comparada a analgesia padrão na função pulmonar, força muscular respiratória e dor no pós-operatório e revascularização do miocárdio: ensaio clínico randonizado

Pós-graduação em Bases Gerais da Cirurgia - FMB

CPAP Has No Effect on Clearance, Sputum Properties, or Expectorated Volume in Cystic Fibrosis

BACKGROUND: Positive expiratory pressure (PEP) is used for airway clearance in cystic fibrosis (CF) patients. Hypertonic saline (HTS) aerosol increases sputum expectoration volume and may improve respiratory secretion properties. CPAP may also be used to maintain airway patency and mobilize secretions. To evaluate if CPAP would increase the beneficial clearance effect of HTS in subjects with CF, we investigated the effects of CPAP alone and CPAP followed by HTS on sputum physical properties and expectoration volume in CF subjects. METHODS: In this crossover study, 15 CF subjects (mean age 19 y old) were randomized to interventions, 48 hours apart: directed coughs (control), CPAP at 10 cm H2O, HTS 7%, and both CPAP and HTS (CPAP+HTS). Sputum collection was performed at baseline and after interventions. Expectorated volume was determined and in vitro sputum properties were analyzed for contact angle and cough clearability. RESULTS: There were no significant differences between any treatment in arterial blood pressure, heart rate, or pulse oximetry, between the 2 time points. HTS and CPAP+HTS improved cough clearability by 50% (P = .001) and expectorated volume secretion by 530% (P = .001). However, there were no differences between control and CPAP on sputum contact angle, cough clearability, or volume of expectorated secretion. CONCLUSIONS: CPAP alone had no effect on mucus clearance, sputum properties, or expectorated volume, and did not potentiate the effect of HTS alone in CF subjects.

Low mechanical ventilation times and reintubation rates associated with a specific weaning protocol in an intensive care unit setting: a retrospective study

OBJECTIVES: A number of complications exist with invasive mechanical ventilation and with the use of and withdrawal from prolonged ventilator support. The use of protocols that enable the systematic identification of patients eligible for an interruption in mechanical ventilation can significantly reduce the number of complications. This study describes the application of a weaning protocol and its results. METHODS: Patients who required invasive mechanical ventilation for more than 24 hours were included and assessed daily to identify individuals who were ready to begin the weaning process. RESULTS: We studied 252 patients with a median mechanical ventilation time of 3.7 days (interquartile range of 1 to 23 days), a rapid shallow breathing index value of 48 (median), a maximum inspiratory pressure of 40 cmH2O, and a maximum expiratory pressure of 40 cm H2O (median). Of these 252 patients, 32 (12.7%) had to be reintubated, which represented weaning failure. Noninvasive ventilation was used postextubation in 170 (73%) patients, and 15% of these patients were reintubated, which also represented weaning failure. The mortality rate of the 252 patients studied was 8.73% (22), and there was no significant difference in the age, gender, mechanical ventilation time, and maximum inspiratory pressure between the survivors and nonsurvivors. CONCLUSIONS: The use of a specific weaning protocol resulted in a lower mechanical ventilation time and an acceptable reintubation rate. This protocol can be used as a comparative index in hospitals to improve the weaning system, its monitoring and the informative reporting of patient outcomes and may represent a future tool and source of quality markers for patient care.

Increased NHE3 abundance and transport activity in renal proximal tubule of rats with heart failure

Inoue BH, dos Santos L, Pessoa TD, Antonio EL, Pacheco BPM, Savignano FA, Carraro-Lacroix LR, Tucci PJF, Malnic G, Girardi ACC. Increased NHE3 abundance and transport activity in renal proximal tubule of rats with heart failure. Am J Physiol Regul Integr Comp Physiol 302: R166-R174, 2012. First published October 26, 2011; doi:10.1152/ajpregu.00127.2011.-Heart failure (HF) is associated with a reduced effective circulating volume that drives sodium and water retention and extracellular volume expansion. We therefore hypothesized that Na(+)/H(+) exchanger isoform 3 (NHE3), the major apical transcellular pathway for sodium reabsorption in the proximal tubule, is upregulated in an experimental model of HF. HF was induced in male rats by left ventricle radiofrequency ablation. Sham-operated rats (sham) were used as controls. At 6 wk after surgery, HF rats exhibited cardiac dysfunction with a dramatic increase in left ventricular end-diastolic pressure. By means of stationary in vivo microperfusion and pH-dependent sodium uptake, we demonstrated that NHE3 transport activity was significantly higher in the proximal tubule of HF compared with sham rats. Increased NHE3 activity was paralleled by increased renal cortical NHE3 expression at both protein and mRNA levels. In addition, the baseline PKA-dependent NHE3 phosphorylation at serine 552 was reduced in renal cortical membranes of rats with HF. Collectively, these results suggest that NHE3 is upregulated in the proximal tubule of HF rats by transcriptional, translational, and posttranslational mechanisms. Enhanced NHE3-mediated sodium reabsorption in the proximal tubule may contribute to extracellular volume expansion and edema, the hallmark feature of HF. Moreover, our study emphasizes the importance of undertaking a cardiorenal approach to contain progression of cardiac disease.

Predicted preoperative maximal static respiratory pressures in adult cardiac surgeries: evaluation of two formulas

Objectives: Cardiac surgery (CC) determines systemic and pulmonary changes that require special care. What motivated several studies conducted in healthy subjects to assess muscle strength were the awareness of the importance of respiratory muscle dysfunction in the development of respiratory failure. These studies used maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) values. This study examined the concordance between the values predicted by the equations proposed by Black & Hyatt and Neder, and the measured values in cardiac surgery (CS) patients. Methods: Data were collected from preoperative evaluation forms. The Lin coefficient and Bland-Altman plots were used for statistical concordance analysis. The multiple linear regression and analysis of variance (ANOVA) were used to produce new formulas. Results: There were weak correlations of 0.22 and 0.19 in the MIP analysis and of 0.10 and 0.32 in the MEP analysis, for the formulas of Black & Hyatt and Neder, respectively. The ANOVA for both MIP and MEP were significant (P <0.0001), and the following formulas were developed: MIP = 88.82 - (0.51 x age) + (19.86 x gender), and MEP = 91.36 -(030 x age) + (29.92 x gender). Conclusions: The Black and Hyatt and Neder formulas predict highly discrepant values of MIP and MEP and should not be used to identify muscle weakness in CS patients.

SMALL INTERFERING RNA TARGETING FOCAL ADHESION KINASE PREVENTS CARDIAC DYSFUNCTION IN ENDOTOXEMIA

Sepsis and septic shock are associated with cardiac depression. Cardiovascular instability is a major cause of death in patients with sepsis. Focal adhesion kinase (FAK) is a potential mediator of cardiomyocyte responses to oxidative and mechanical stress. Myocardial collagen deposition can affect cardiac compliance and contractility. The aim of the present study was to determine whether the silencing of FAK is protective against endotoxemia-induced alterations of cardiac structure and function. In male Wistar rats, endotoxemia was induced by intraperitoneal injection of lipopolysaccharide (10 mg/kg). Cardiac morphometry and function were studied in vivo by left ventricular catheterization and histology. Intravenous injection of small interfering RNA targeting FAK was used to silence myocardial expression of the kinase. The hearts of lipopolysaccharide-injected rats showed collagen deposition, increased matrix metalloproteinase 2 activity, and myocyte hypertrophy, as well as reduced 24-h +dP/dt and -dP/dt, together with hypotension, increased left ventricular end-diastolic pressure, and elevated levels of FAK (phosphorylated and unphosphorylated). Focal adhesion kinase silencing reduced the expression and activation of the kinase in cardiac tissue, as well as protecting against the increased collagen deposition, greater matrix metalloproteinase 2 activity, and reduced cardiac contractility that occur during endotoxemia. In conclusion, FAK is activated in endotoxemia, playing a role in cardiac remodeling and in the impairment of cardiac function. This kinase represents a potential therapeutic target for the protection of cardiac function in patients with sepsis.

Insulin alone or with captopril: effects on signaling pathways (AKT and AMPK) and oxidative balance after ischemia-reperfusion in isolated hearts

Insulin and the inhibition of the reninangiotensin system have independent benefits for ischemiareperfusion injury, but their combination has not been tested. Our aim was to evaluate the effects of insulin+captopril on insulin/angiotensin signaling pathways and cardiac function in the isolated heart subjected to ischemiareperfusion. Isolated hearts were perfused (Langendorff technique) with KrebsHenseleit (KH) buffer for 25 min. Global ischemia was induced (20 min), followed by reperfusion (30 min) with KH (group KH), KH+angiotensin-I (group A), KH+angiotensin-I+captopril (group AC), KH+insulin (group I), KH+insulin+angiotensin-I (group IA), or KH+insulin+angiotensin-I+captopril (group IAC). Group A had a 24% reduction in developed pressure and an increase in end-diastolic pressure vs. baseline, effects that were reverted in groups AC, IA, and IAC. The phosphorylation of protein kinase B (AKT) was higher in groups I and IA vs. groups KH and A. The phosphorylation of AMP-activated protein kinase (AMPK) was similar to 31% higher in groups I, IA, and IAC vs. groups KH, A, and AC. The tert-butyl hydroperoxide (tBOOH)-induced chemiluminescence was lower (similar to 2.2 times) in all groups vs. group KH and was similar to 35% lower in group IA vs. group A. Superoxide dismutase content was lower in groups A, AC, and IAC vs. group KH. Catalase activity was similar to 28% lower in all groups (except group IA) vs. group KH. During reperfusion of the ischemic heart, insulin activates the AKT and AMPK pathways and inhibits the deleterious effects of angiotensin-I perfusion on SOD expression and cardiac function. The addition of captopril does not potentiate these effects.