Microvascular endothelial dysfunction during cardiopulmonary bypass in surgery for correction of cyanotic and acyanotic congenital heart disease.

OBJECTIVE: To evaluate endothelium-dependent microvascular reactivity during cardiopulmonary bypass (CPB) in surgery for the correction of cyanotic and acyanotic congenital heart disease (CHD) in children and infants using laser Doppler perfusion monitoring (LDPM). METHODS: This cross-sectional observational study included one hundred consecutive acyanotic (AC, n = 61) and cyanotic (C, n = 39) pediatric patients scheduled for cardiac surgery for correction of CHD. The endothelium-dependent microvascular vasodilation of the skin of the forehead was evaluated using a single-point LDPM coupled with local thermal hyperemia (LTH). RESULTS: LTH induced significant increases in microvascular conductance both in AC and C patients after the induction of anesthesia, during CPB and after weaning from CPB. Nevertheless, the vasodilation induced by LTH was significantly blunted during CPB when compared with values obtained after the induction of anesthesia both in AC and C patients. Microvascular endothelial reactivity nearly normalized after the discontinuation of CPB. CONCLUSION: The evaluation of systemic microvascular reactivity on the forehead skin of infants and children using LDPM appears to be a valuable tool for optimizing microvascular perfusion during CPB in pediatric cardiac surgery.

Peripheral oxygen saturation, heart rate, and blood pressure during dental treatment of children with cyanotic congenital heart disease.

OBJECTIVES: In this observational study, we evaluated the peripheral oxygen saturation (SpO2), heart rate, and blood pressure of children with cyanotic congenital heart disease who were undergoing dental extraction. METHODS: Forty-four patients between the ages of 6 and 12 years who underwent upper primary tooth extraction were included in the study. Of these, 20 patients were in the cyanotic congenital heart disease group and 24 were in the control group. RESULTS: Peripheral oxygen saturation, heart rate, and systolic blood pressure in the cyanotic congenital heart disease group varied quite significantly during the treatment protocol (p<0.05), with values of 80.5% (±7.6) to 82.8% (±7.8), 95.3 beats per minute (bpm) (±11.3) to 101.3 bpm (±9.8), and 93.6 mm Hg (±13,3) to 103.8 mm Hg (±12.7), respectively. The variations in the control group during the procedure were also significant. CONCLUSIONS: The changes observed during the study protocol, although statistically significant, were mild and lacked clinical relevance. The results indicate that dental treatment of children with cyanotic heart disease using a standardized protocol in decentralized offices without the support of a surgical center is safe.

Peripheral oxygen saturation, heart rate, and blood pressure during dental treatment of children with cyanotic congenital heart disease

OBJECTIVES: In this observational study, we evaluated the peripheral oxygen saturation (SpO2), heart rate, and blood pressure of children with cyanotic congenital heart disease who were undergoing dental extraction. METHODS: Forty-four patients between the ages of 6 and 12 years who underwent upper primary tooth extraction were included in the study. Of these, 20 patients were in the cyanotic congenital heart disease group and 24 were in the control group. RESULTS: Peripheral oxygen saturation, heart rate, and systolic blood pressure in the cyanotic congenital heart disease group varied quite significantly during the treatment protocol (p<0.05), with values of 80.5% (±7.6) to 82.8% (±7.8), 95.3 beats per minute (bpm) (±11.3) to 101.3 bpm (±9.8), and 93.6 mm Hg (±13,3) to 103.8 mm Hg (±12.7), respectively. The variations in the control group during the procedure were also significant. CONCLUSIONS: The changes observed during the study protocol, although statistically significant, were mild and lacked clinical relevance. The results indicate that dental treatment of children with cyanotic heart disease using a standardized protocol in decentralized offices without the support of a surgical center is safe. .

eNOS se correlaciona com a biogênese mitocondrial em corações com cardiopatia congênita e cianose / eNOS correlates with mitochondrial biogenesis in hearts of congenital heart disease with cyanosis

FUNDAMENTO: O programa de biogênese mitocondrial no coração parece apresentar remodelação adaptativa após estresse biomecânico e oxidativo. Os mecanismos adaptativos que protegem o metabolismo do miocárdio durante a hipóxia são coordenados, em parte, pelo óxido nítrico (NO). OBJETIVO: Observar a biogênese mitocondrial e expressão do óxido nítrico sintase (NOS) em corações de cardiopatia congênita com cianose; discutir a resposta mitocondrial à hipóxia crônica do miocárdio. MÉTODOS: Foram investigados 20 pacientes com defeitos cardíacos cianóticos (n = 10) ou acianóticos (n = 10). Foram estudadas amostras do miocárdio na via de saída ventricular direita, tomadas durante a operação. A análise morfométrica de mitocôndrias foi realizada por microscopia eletrônica de transmissão. A relação mtDNA/nDNA foi determinada com PCR em tempo real. Os níveis de transcrição da subunidade I da citocromo c oxidase (COXI), coativador-1α do receptor γ ativado por proliferador de peroxissoma (PGC-1α), o fator respiratório nuclear 1 (NRF1), e fator de transcrição mitocondrial A (Tfam) foram detectados por reação em cadeia da polimerase via transcriptase reversa (RT-PCR) ativado por fluorescência em tempo real. Os níveis proteicos de COXI e nNOS, iNOS e eNOS foram medidos por técnica de Western Blot. RESULTADOS: A densidade volumétrica mitocondrial (Vv) e a densidade numérica (Nv) foram significativamente elevadas em pacientes com cianose, em comparação com a cardiopatia congênita acianótica. MtDNA elevada e suprarregulação dos níveis de COXI, PGC-1 α, NRF1 e Tfam mRNA foram observadas em pacientes cianóticos. Os níveis de proteína de COXI e eNOS foram significativamente maiores no miocárdio de pacientes cianóticos que nos de acianóticos. Os níveis de transcrição do PGC-1α se correlacionam com os níveis de eNOS. CONCLUSÃO: A biogênese mitocondrial é ativada no miocárdio da via de saída ventricular na cardiopatia congênita com cianose, que ...

BACKGROUND: Mitochondrial biogenesis program in heart appears to exhibit adaptive remodeling following biomechanical and oxidative stress. The adaptive mechanisms that protect myocardium metabolism during hypoxia are coordinated in part by nitric oxide (NO). OBJECTIVE: To observe mitochondrial biogenesis and nitric oxide synthase (NOS) expression in hearts of congenital heart disease with cyanosis, discuss mitochondrial response to chronic hypoxia in myocardium. METHODS: 20 patients with cyanotic (n=10) or acyanotic cardiac defects (n=10) were investigated. Samples from the right ventricular outflow tract myocardium taken during operation were studied. Morphometric analysis of mitochondria was performed with transmission electron microscope. Relative mtDNA/nDNA ratio was determined with real-time PCR. Cytochrome c oxidase subunit I (COXI), peroxisome-proliferator-activated receptor γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (Tfam) transcript levels were detected by real-time fluorescent RT-PCR. COXI and nNOS, iNOS and eNOS protein levels were measured with western blot. RESULTS: Mitochondrial volume density (Vv) and numerical density (Nv) were significantly elevated in patients with cyanotic compared to acyanotic congenital heart disease. Elevated mtDNA and up-regulated COXI, PGC-1α, NRF1 and Tfam mRNA levels were observed in cyanotic patients. Protein levels of COXI and eNOS were significantly higher in the myocardium of cyanotic than of acyanotic patients. PGC-1α transcript levels correlated with the levels of eNOS. Conclusion: Mitochondrial biogenesis is activated in right ventricular outflow tract myocardium in congenital heart disease with cyanosis, which could be the adaptive response to chronic hypoxia and possibly involves eNOS up-regulation. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0).

eNOS correlates with mitochondrial biogenesis in hearts of congenital heart disease with cyanosis.

BACKGROUND: Mitochondrial biogenesis program in heart appears to exhibit adaptive remodeling following biomechanical and oxidative stress. The adaptive mechanisms that protect myocardium metabolism during hypoxia are coordinated in part by nitric oxide (NO). OBJECTIVE: To observe mitochondrial biogenesis and nitric oxide synthase (NOS) expression in hearts of congenital heart disease with cyanosis, discuss mitochondrial response to chronic hypoxia in myocardium. METHODS: 20 patients with cyanotic (n=10) or acyanotic cardiac defects (n=10) were investigated. Samples from the right ventricular outflow tract myocardium taken during operation were studied. Morphometric analysis of mitochondria was performed with transmission electron microscope. Relative mtDNA/nDNA ratio was determined with real-time PCR. Cytochrome c oxidase subunit I (COXI), peroxisome-proliferator-activated receptor γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (Tfam) transcript levels were detected by real-time fluorescent RT-PCR. COXI and nNOS, iNOS and eNOS protein levels were measured with western blot. RESULTS: Mitochondrial volume density (Vv) and numerical density (Nv) were significantly elevated in patients with cyanotic compared to acyanotic congenital heart disease. Elevated mtDNA and up-regulated COXI, PGC-1α, NRF1 and Tfam mRNA levels were observed in cyanotic patients. Protein levels of COXI and eNOS were significantly higher in the myocardium of cyanotic than of acyanotic patients. PGC-1α transcript levels correlated with the levels of eNOS. CONCLUSION: Mitochondrial biogenesis is activated in right ventricular outflow tract myocardium in congenital heart disease with cyanosis, which could be the adaptive response to chronic hypoxia and possibly involves eNOS up-regulation.

Cianose / Cyanosis

Denomina-se cianose a coloraçao azulada da pele e/ou mucosas provocada pelo aumento na quantidade absoluta de hemoglobina insaturada na rede capilar periférica, principalmente nos plexos venosos subpapilares. Na ausência de condiçoes clínicas associadas à lentidao de fluxo sangüíneo periférico, que cursa com elevada taxa de extraçao de O2 para os tecidos (cianose periférica), a presença de cianose geralmente implica em hipoxemia arterial (cianose central), constataçao suficiente para proceder-se à análise da gasometria arterial que, nesta situaçao, pode assumir propósito diagnóstico com implicaçoes terapêuticas. Assim, buscou-se abordar de forma sucinta e objetiva os mecanismos básicos envolvidos na gênese da cianose de origem central (geralmente doenças pulmonares e/ou cardiocirculatórias) e periférica, bem como as particularidades clínicas/semiológicas comuns a cada tipo, atitude esta indispensável para a abordagem do diagnóstico diferencial da causa subjacente. A presença de pigmentos anormais no sangue, como a metahemoglobina ou bilirrubina, podem complicar a detecçao da cianose. A mesma dificuldade pode ocorrer na presença de anemias graves.

Bases da conduta nas cardiopatias congênitas cianóticas / The basis of conduct on the cyanotic congenital cardiopathy

O autor diligencia abordar os aspectos básicos das Cardiopatias Congênitas Cianogênicas, fundamentando-se nos conceitos atuais que abarcam a sua fisiopatologia, comemorativos clínicos, investigaçäo propedêutica e conduta terapêutica.

Oxygen desaturation during sleep in infants and young children with congenital heart disease.

Oxygen saturation (SaO2) during sleep and pulmonary functions were evaluated in 19 infants with congenital heart disease, aged 6 +/- 4 months, and in 11 normal infants, aged 8 +/- 5 months, to determine whether infants with congenital heart disease have more frequent oxygen desaturation during sleep and, if so, its relationship to underlying pulmonary function. Infants with congenital heart disease were classified as acyanotic (n = 11) or cyanotic (n = 8) on the basis of their aortic SaO2 at the time of cardiac catheterization (greater or less than 90% SaO2). Pulmonary function tests included respiratory rate, functional residual capacity, total respiratory system compliance, and maximal flows at functional residual capacity. Significant differences were found in the values for the lowest SaO2 of each 5-minute epoch (SaO2L) averaged during the entire sleep time (normal 94% +/- 2%, acyanotic 90% +/- 3%, and cyanotic 74% +/- 4%; p less than 0.01). The three groups also differed significantly in frequency distributions of percentage of total sleep time with SaO2L less than 90% (SaO2%T) (normal 10% +/- 17%, acyanotic 36% +/- 34%, and cyanotic 97% +/- 4%; p less than 0.05). Compared with the control group, the acyanotic group had a higher respiratory rate (66 +/- 19 breaths/min vs 35 +/- 6 breaths/min; p less than 0.01), a lower tidal volume (65% +/- 29% predicted vs 105% +/- 18% predicted; p less than 0.01), and a lower total respiratory compliance (59% +/- 18% predicted vs 106% +/- 30% predicted; p less than 0.01). A negative correlation existed between SaO2%T and aortic SaO2 (R2 = 0.64; p less than 0.01). We conclude that oxygen desaturation occurs during sleep in infants with congenital heart disease; the presence of desaturation appears to be related to the initial degree of hypoxemia and the presence of abnormal pulmonary function.