Functional capacity in a rat model of heart failure: impact of myocardial infarct size.

NEW FINDINGS: What is the central question of this study? To the best of our knowledge, no studies have evaluated oxygen uptake, carbon dioxide production and exercise tolerance in rats that have undergone myocardial infarction classified by myocardial infarct (MI) size. What is the main finding and its importance? Oxygen uptake and exercise intolerance are MI size dependent, and classification based on MI size can distinguish rats with functional capacity impairment. Rats with a large MI (>40% of the left ventricle) might provide a good model for the testing of new therapies that have the potential to modify the variables of functional capacity. Oxygen uptake (V̇O2) and exercise tolerance in rats classified by myocardial infarct (MI) size are underexplored. The aim of this study was to evaluate V̇O2, carbon dioxide production (V̇CO2) and exercise tolerance in rats that had undergone myocardial infarction. Fourteen weeks after myocardial infarction or sham surgery, rats underwent an integrated approach to evaluation of left ventricular function and V̇O2/V̇O2V̇CO2V̇CO2, exercise tolerance and skeletal muscle weight. Based on determination of MI size, rats were assigned to sham-operated controls (Sham, n = 12), small myocardial infarction (SMI, n = 8) and large myocardial infarction (LMI, n = 5) groups. The LMI rats showed lower systolic (ejection fraction and fractional shortening) and diastolic (E/A ratio) left ventricular function compared with SMI. Maximal V̇O2 (∼24%, P < 0.05), V̇O2 reserve (∼30%, P < 0.05), time to exhaustion (∼36%, P < 0.05) and maximal velocity (∼30%, P < 0.05) were lower in LMI compared with sham-operated control animals, with no difference between SMI rats and sham-operated controls. Maximal V̇CO2 and respiratory exchange ratio showed no significant difference between MI rats and sham-operated control rats. The LMI rats demonstrated lower gastrocnemius weight (∼12%, P < 0.05) and soleus weight (∼19%, P = 0.07) compared with sham-operated control rats. Significant correlations between MI size, left ventricular end-diastolic pressure, right ventricle hypertrophy, pulmonary congestion, ejection fraction and fractional shortening with maximal V̇O2 and distance run were observed. Oxygen uptake and exercise intolerance are MI size dependent.

Maximal oxygen uptake and exercise tolerance are improved in rats with heart failure subjected to low-level laser therapy associated with resistance training.

Exercise tolerance and maximal oxygen uptake (VO2max) are reduced in heart failure (HF). The influence of combined resistance training (RT) and low-level laser therapy (LLLT) on exercise tolerance and VO2max in HF has not yet been explored. The aim of this study was to evaluate the influence of combined RT and LLLT on VO2max and exercise tolerance in rats with HF induced by myocardial infarction (MI). Rats were allocated to sedentary sham (Sed-Sham, n = 12), sedentary heart failure (Sed-HF, n = 9), RT heart failure (RT-HF, n = 7) and RT associated with LLLT heart failure (RT + LLLT-HF, n = 7) groups. After MI or sham surgery, rats underwent a RT and LLLT protocol (applied immediately after RT) for 8 weeks. VO2max and exercise tolerance were evaluated at the end of protocol. HF rats subjected to LLLT combined with RT showed higher VO2basal (41 %), VO2max (40 %), VO2reserve (39 %), run distance (46 %), time to exhaustion (30 %) and maximal velocity (22 %) compared with HF rats that underwent RT alone. LLLT associated with RT improved oxygen uptake and exercise tolerance compared with RT alone in HF rats.

Cardiac rehabilitation programme after transcatheter aortic valve implantation versus surgical aortic valve replacement: Systematic review and meta-analysis.

Background Aortic stenosis is a valvular heart disease characterised by fixed obstruction of the left ventricular outflow. It can be managed by surgical aortic valve replacement (sAVR) or transcatheter aortic valve implantation (TAVI). This review aimed to describe the evidence supporting a cardiac rehabilitation programme on functional capacity and quality of life in aortic stenosis patients after sAVR or TAVI. Methods The search was conducted on multiple databases from January to March 2016. All studies were eligible that evaluated the effects of a post-interventional cardiac rehabilitation programme in aortic stenosis patients. The methodological quality was assessed using the PEDro scale. Meta-analysis was performed separately by procedure and between procedures. The walked distance during the six-minute walk test (6MWD) and Barthel index were evaluated. The analysis was conducted in Review Manager. Results Five studies were included (292 TAVI and 570 sAVR patients). The meta-analysis showed that a cardiac rehabilitation programme was associated with a significant improvement in 6MWD (0.69 (0.47, 0.91); P < 0.001) and Barthel index (0.80 (0.29, 1.30); P = 0.002) after TAVI and 6MWD (0.79 (0.43, 1.15); P < 0.001) and Barthel index (0.93 (0.67, 1.18); P < 0.001) after sAVR. In addition, the meta-analysis showed that the cardiac rehabilitation programme promoted a similar gain in 6MWD (4.28% (-12.73, 21.29); P = 0.62) and Barthel index (-1.52 points (-4.81, 1.76); P = 0.36) after sAVR or TAVI. Conclusions The cardiac rehabilitation programme improved the functional capacity and quality of life in aortic stenosis patients. Patients who underwent TAVI benefitted with a cardiac rehabilitation programme similar to sAVR patients.

Aortic-banding induces myocardial oxidative stress and changes in concentration and activity of antioxidants in male Wistar rats.

Myocardial activity and gene expression of antioxidant defenses and oxidative damage were examined in an experimental model of pressure overload hypertrophy. Male Wistar rats were divided into abdominal aortic-banded or sham-operated groups. After 30 days, arterial pressure and heart rate were measured. Heart, lung, and liver were extracted and weighted to evaluate cardiac hypertrophy and pulmonary and hepatic congestion. Heart homogenates were prepared to quantify lipid peroxidation (LPO); the activities of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GPx) and glutathione reductase (GR); and Cu-Zn SOD and GST concentrations. Total glutathione (GSH) myocardial content was also measured. Arterial pressure (142 +/- 17 mmHg) and cardiac hypertrophy index (3.4 +/- 0.45 mg/g) were significantly increased (by 38% and 22%, respectively, p<0.0001) in the aortic-banded group. LPO was enhanced by 55% in the aortic-banded group (11891 +/- 766 cps/mg protein, p<0.001) compared with that in the controls. SOD activity and concentration were higher (40% and 38%, 15.15 +/- 1.03 U/mg protein, 49.187 pixels, respectively, p<0.05) in the aortic-banded group than in the controls. Aortic-banding induced a decrease by 28% in GST (48 +/- 10 pmol/min/mg protein, p<0.005), by 36% in GPx (38.2 +/- 9.5 nmol/min/mg protein, p<0.005), by 31% in GR activities (1.55 +/- 0.23 nmol/mg protein, p<0.0005), and by 43% in GSH content (0.13 +/- 0.02 nmol/mg protein, p<0.005). In conclusion, in this model it was observed that myocardial oxidative stress induces alterations in antioxidant enzyme activities and protein expression. The follow up of these parameters could afford an early therapeutical window to avoid heart failure progression.

Aortic Center: specialized care improves outcomes and decreases mortality.

OBJECTIVE: To compare in-hospital outcomes in aortic surgery in our cardiac surgery unit, before and after foundation of our Center for Aortic Surgery (CTA). METHODS: Prospective cohort with non-concurrent control. Foundation of CTA required specialized training of surgical, anesthetic and intensive care unit teams, routine neurological monitoring, endovascular and hybrid facilities, training of the support personnel, improvement of the registry and adoption of specific protocols. We included 332 patients operated on between: January/2003 to December/2007 (before-CTA, n=157, 47.3%); and January/2008 to December/2010 (CTA, n=175, 52.7%). Baseline clinical and demographic data, operative variables, complications and in-hospital mortality were compared between both groups. RESULTS: Mean age was 58±14 years, with 65% male. Group CTA was older, had higher rate of diabetes, lower rates of COPD and HF, more non-urgent surgeries, endovascular procedures, and aneurysms. In the univariate analysis, CTA had lower mortality (9.7 vs. 23.0%, P=0.008), which occurred consistently across different diseases and procedures. Other outcomes which were reduced in CTA included lower rates of reinterventions (5.7 vs 11%, P=0.046), major complications (20.6 vs. 33.1%, P=0.007), stroke (4.6 vs. 10.9%, P=0.045) and sepsis (1.7 vs. 9.6%, P=0.001), as compared to before-CTA. Multivariable analysis adjusted for potential confounders revealed that CTA was independently associated with mortality reduction (OR=0.23, IC 95% 0.08 - 0.67, P=0.007). CTA independent mortality reduction was consistent in the multivariable analysis stratified by disease (aneurysm, OR=0.18, CI 95% 0.03 - 0.98, P=0.048; dissection, OR=0.31, CI 95% 0.09 - 0.99, P=0.049) and by procedure (hybrid, OR=0.07, CI 95% 0.007 - 0.72, P=0.026; Bentall, OR=0.18, CI 95% 0.038 - 0.904, P=0.037). Additional multivariable predictors of in-hospital mortality included creatinine (OR=1.7 [1.1-2.6], P=0.008), urgent surgery (OR=5.0 [1.5-16.7], P=0.008) and thoracoabdominal aneurysm (OR=24.6 [3.1-194.1], P=0.002). CONCLUSION: Thoracic aorta surgery in specialized center was associated with lower incidence of complications and all-cause mortality as compared to usual care.

Aortic Center: specialized care improves outcomes and decreases mortality / Centro de Tratamento da Aorta: a especialização reduz complicações e mortalidade

Objective: To compare in-hospital outcomes in aortic surgery in our cardiac surgery unit, before and after foundation of our Center for Aortic Surgery (CTA). Methods: Prospective cohort with non-concurrent control. Foundation of CTA required specialized training of surgical, anesthetic and intensive care unit teams, routine neurological monitoring, endovascular and hybrid facilities, training of the support personnel, improvement of the registry and adoption of specific protocols. We included 332 patients operated on between: January/2003 to December/2007 (before-CTA, n=157, 47.3%); and January/2008 to December/2010 (CTA, n=175, 52.7%). Baseline clinical and demographic data, operative variables, complications and in-hospital mortality were compared between both groups. Results: Mean age was 58±14 years, with 65% male. Group CTA was older, had higher rate of diabetes, lower rates of COPD and HF, more non-urgent surgeries, endovascular procedures, and aneurysms. In the univariate analysis, CTA had lower mortality (9.7 vs. 23.0%, P=0.008), which occurred consistently across different diseases and procedures. Other outcomes which were reduced in CTA included lower rates of reinterventions (5.7 vs 11%, P=0.046), major complications (20.6 vs. 33.1%, P=0.007), stroke (4.6 vs. 10.9%, P=0.045) and sepsis (1.7 vs. 9.6%, P=0.001), as compared to before-CTA. Multivariable analysis adjusted for potential counfounders revealed that CTA was independently associated with mortality reduction (OR=0.23, IC 95% 0.08 – 0.67, P=0.007). CTA independent mortality reduction was consistent in the multivariable analysis stratified by disease (aneurysm, OR=0.18, CI 95% 0.03 – 0.98, P=0.048; dissection, OR=0.31, CI 95% 0.09 – 0.99, P=0.049) and by procedure (hybrid, OR=0.07, CI 95% 0.007 – 0.72, P=0.026; Bentall, OR=0.18, CI 95% 0.038 – 0.904, P=0.037). Additional multivariable predictors of in-hospital mortality included creatinine ...

Objetivo: Comparar desfechos intrahospitalares em pacientes submetidos a cirurgia da aorta torácica e toracoabdominal, antes e após a constituição do Centro Especializado de Tratamento da Aorta (CTA). Métodos: Coorte prospectiva com controle não contemporâneo. A criação do CTA envolveu treinamento cirúrgico especializado, sala híbrida, monitorização neurológica, capacitação de pessoal de apoio, aperfeiçoamento dos registros e uso de protocolos específicos. Foram incluídos 332 pacientes operados em 2 períodos: janeiro/2003 a dezembro/2007 (pré-CTA, n=157, 47,3%); e janeiro/2008 a dezembro/2010 (CTA, n=175, 52,7%). As características demográficas, clínicas, dados cirúrgicos, complicações e mortalidade hospitalar foram comparados nos 2 grupos. Resultados: A idade média foi 58±14 anos, com 65% sexo masculino. O grupo CTA teve idade, prevalência de diabete (DM) e glicemia maiores; menor prevalência de doença pulmonar obstrutiva crônica e insuficiência cardíaca; maior proporção de aneurismas e cirurgias eletivas; e mais procedimentos endovasculares que o pré-CTA. Na análise univariada, o grupo CTA mostrou redução de mortalidade (9,7% x 23,0%, P=0,008), que foi consistente nos diferentes subgrupos estratificados por patologia e por procedimento. O grupo CTA teve também redução de reoperações (5,7% x 11%, P=0,046), complicações maiores (20,6% x 33,1%, P=0,007), acidente vascular cerebral (4,6% x 10,9%, P=0,045) e sepse (1,7% x 9,6%, P=0,001), comparado ao pré-CTA. Na análise multivariada, o CTA se associou de forma independente a redução de mortalidade hospitalar (OR=0,23, IC 95% 0,08 - 0,67, P=0,007). A redução de mortalidade do CTA também ocorreu na análise estratificada por patologia (cirurgias de aneurisma, OR=0,18, IC 95% 0,03 - 0,98, P=0,048; cirurgias de dissecção, OR=0,31, IC 95% 0,09 - 0,99, P=0,049) e por procedimento (híbridos, OR=0,07, IC 95% 0,007 - 0,72, P=0,026; Bentall, OR=0,18, IC 95% 0,038 – 0,904, P=0,037). Também foram ...

Constipacao intestinal da infancia: um estudo de prevalencia / Intestinal constipation in childhood: a prevalence study

Os autores apresentam os resultados de um estudo de prevalencia de constipacao intestinal em 1005 criancas, que aguardavam consulta em ambulatorio do INAMPS e Hospital da Crianca Santo Antonio. Detectou-se 367 (36,61% ) criancas constipadas. Sao ainda discutidos os seguintes itens:sexo e faixa etaria das criancas constipadas, historia familiar de constipacao cronica, idade de inicio da educacao esfincteriana e procura especifica de tratamento para constipacao durante a evolucao