30 research outputs found

    Myocardium tissue changes caused by electrical transthoracic discharges in rats

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    <p>Abstract</p> <p>Background</p> <p>Cardiomyocytes cytoarchitecture changes caused by transthoracic countershocks have been focused recently. We aimed to evaluate the effects of electrical discharge application in the mitochondria structure in atrial myocardium of rats.</p> <p>Methods</p> <p>An electrical cardioverter was adapted to small rodent animals for our research. Electrical discharges were applied to the precordial region of 30 albino rats: (1) control group - animals that remained on resting period and were afterwards sacrificed; (2) electrical discharge group - animals that remained on resting period, followed by ten electrical discharges of 300 mV and sacrificed, and; (3) electrical post-discharge group - animals that remained on a resting period and received ten electrical discharges like the electrical discharge group, but were sacrificed seven days subsequently. We examined liver, adrenal and left atrium tissue fragments of the three groups.</p> <p>Results</p> <p>It was observed in control and post-discharge groups a normal cellular structure aspect with preserved architecture of cardiomyocytes and continuous sarcoplasmic membrane integrity. On the other hand, cardiac muscle fibers with mitochondrial edema and lysis occurred in the discharge group. Glycogen and adrenal lipids were not depleted in all groups.</p> <p>Conclusion</p> <p>These data suggest that transthoracic electrical discharges induce mitochondrial injuries in atrial cardiac cells of rats.</p

    Increase in systolic blood pressure during exercise testing after heart transplantation: correlation with the clinical condition and ventricular function assessed by dobutamine stress echocardiography

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    OBJECTIVE: Patients who underwent heart transplantation (HTX) experience a reduction in the elevation that is usual in systolic blood pressure during exercise testing. Of unknown origin, this phenomenon varies in frequency and intensity. The aim of this study was to analyze the relationship between systolic blood pressure increase (delta SBP) and clinical aspects, as well as variables measured during exercise testing (ET) and dobutamine stress echocardiography (DSE) in patients in the late post-transplantation course. METHODS: Forty-five men, mean age 49.04 ± 10.19, underwent clinical assessment, ET and DSE 40.91 ± 27.46 months after heart transplantation. Left ventricular wall motion score index and ejection fraction were assessed. Delta SBP < 35mmHg during ET was considered abnormal (SBC,1995). RESULTS: No significant correlation was found between delta SBP and post-transplantation time, graft ischemic time, history of rejection, diltiazem dosage, oxygen uptake, ejection fraction, and wall motion score index (WMSI). Delta SBP was normal in 17 patients (Group I) and abnormal in 28 (Group II). Patients of both groups did not differ significantly in regard to clinical features and ET and DSE results. CONCLUSION: Unlike other populations, no correlation was found between delta SBP during exercise testing and clinical condition or left ventricular function in heart transplant patients. Pathophysiological factors associated with delta SBP reduction during exercise testing remain unknown.OBJETIVO: Em pacientes submetidos a transplante cardíaco (TxC) descreve-se redução da elevação da pressão arterial durante o teste ergométrico (TE). Este fenômeno, cuja origem é desconhecida, ocorre em freqüência e intensidade variáveis. O objetivo deste estudo foi verificar a relação entre o incremento da pressão arterial sistólica (deltaPAS) e aspectos clínicos, bem como as variáveis aferidas no TE e ecocardiograma sob estresse pela dobutamina (EED), em pacientes na fase tardia após TxC. MÉTODOS: Quarenta e cinco homens, 49,04±10,19 anos, 40,91±27,46 meses pós-TxC submeteram-se a avaliação clínica, TE e EED . Avaliou-se o índice de contratilidade segmentar e a fração de ejeção de ventrículo esquerdo. Consideraram-se anormais deltaPAS<35mmHg no TE (SBC,1995). RESULTADOS: Não houve correlação significativa entre deltaPAS e o tempo de evolução do transplante, tempo de isquemia do enxerto, antecedentes de rejeição, dose de diltiazem, consumo de oxigênio estimado, fração de ejeção e índice de contratilidade segmentar. O deltaPAS foi normal em 17 casos (Grupo I) e anormal em 28 pacientes (Grupo II). Não houve diferenças significativas entre os pacientes de ambos os grupos em relação aos aspectos clínicos e aos resultados do TE e EED. CONCLUSÃO: Ao contrário de outras populações, os autores não detectaram correlações entre deltaPAS e o quadro clínico e a função ventricular esquerda em pacientes com TxC. Os fatores associados à redução do deltaPAS no TE pós-TxC permanecem desconhecidos.Universidade Federal de São Paulo (UNIFESP) EPMUNIFESP, EPMSciEL

    Unsupervised Rehabilitation: effects of Exercise Training over the Long Run

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    OBJECTIVE: To assess the safety and efficacy of unsupervised rehabilitation (USR) in the long run in low-risk patients with coronary artery disease. METHODS: We carried out a retrospective study with 30 patients divided into: group I (GI) - 15 patients from private clinics undergoing unsupervised rehabilitation; group II (GII) - control group, 15 patients from ambulatory clinic basis, paired by age, sex, and clinical findings. GI was stimulated to exercise under indirect supervision (jogging, treadmill, and sports). GII received the usual clinical treatment. RESULTS: The pre- and postobservation values in GI were, respectively: VO2peak (mL/kg/min), 24±5 and 31± 9; VO2 peak/peak HR: 0.18±0.05 and 0.28±0.13; peak double product (DP peak):26,800±7,000 and 29,000 ± 6,500; % peak HR/predicted HRmax: 89.5±9 and 89.3±9. The pre- and post- values in GII were: VO2 peak (mL/kg/min), 27± 7 and 28±5; VO2 peak/peak HR: 0.2±0.06 and 0.2± 0.05; DP peak: 24,900±8,000 and 25,600± 8,000, and % peak HR/predicted HRmax: 91.3±9 and 91.1± 11. The following values were significant: preobservation VO2peak versus postobservation VO2peak in GI (p=0.0 063); postobservation VO2peak in GI versus postobservation VO2peak in GII (p=0.0045); postobservation VO2 peak/peak HR GI versus postobservation peak VO2/peak HR in GII (p=0.0000). The follow-up periods in GI and GII were, respectively, 41.33± 20.19 months and 20.60±8.16 months (p<0.05). No difference between the groups was observed in coronary risk factors, therapeutic management, or evolution of ischemia. No cardiovascular events secondary to USR were observed in 620 patient-months. CONCLUSION: USR was safe and efficient, in low-risk patients with coronary artery disease and provided benefits at the peripheral level
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