Acute Effects of Maternal Smoking on Fetal-Placental-Maternal System Hemodynamics

OBJECTIVE: To study acute hemodynamic alterations in the fetal-placental maternal system immediately after maternal exposure to nicotine. METHODS: This is a noncontrolled experimental study involving 21 pregnant smoking women, randomly selected, with uncomplicated pregnancies and without risk factors for fetal heart disease. Patients underwent ultrasound and fetal echocardiography before and after smoking a cigarette. They were asked to abstain from smoking for 12 hours before the study. The mean nicotine content of the cigarettes used in the study was 0.5mg of nicotine and 6mg of carbon monoxide. RESULTS: The average number of cigarettes smoked per a day prior to the study was 9.67. Gestational age ranged between 18 and 36 weeks. The mean maternal heart rate was elevated (P<0.001) as was the mean fetal heart rate (P=0.044). Maternal systolic blood pressure (P=0.004) and diastolic blood pressure (P=0.033) were also elevated after smoking. A decrease occurred in the systolic/diastolic ratio in the right uterine artery (P=0.014) and in the left uterine artery (P=0.039). The other hemodynamic variables remained unchanged. CONCLUSION: Cigarette smoking can cause changes in physiologic variables of fetal-placental circulation, but it does not change fetal cardiac function, in the dose of nicotine and its components used in this study. The decrease in systolic/diastolic ratio in the uterine arteries is probably related to a dose-dependent nicotine pattern.

Arterial Hypertension in a Child with Williams-Beuren Syndrome (7q11.23 Chromosomal Deletion)

We report the case of a 7-year-old male child diagnosed with Williams-Beuren syndrome and arterial hypertension refractory to clinical treatment. The diagnosis was confirmed by genetic study. Narrowing of the descending aorta and stenosis of the renal arteries were also diagnosed. Systemic vascular alterations caused by deletion of the elastin gene may occur early in individuals with Williams-Beuren syndrome, leading to the clinical manifestation of systemic arterial hypertension refractory to drug treatment.

Myocardial Bridges and their Relationship to the Anterior Interventricular Branch of the Left Coronary Artery

OBJECTIVE: To analyze the relationship between myocardial bridges and the anterior interventricular branch (anterior descending) of the left coronary artery. METHODS: The study was carried out with postmortem material, and methods of dissection and observation were used. We assessed the perimeter of the anterior interventricular branch of the left coronary artery using a pachymeter, calculated its proximal and distal diameters in relation to the myocardial bridge, and also its diameter under the myocardial bridge in 30 hearts. We also observed the position of the myocardial bridge in relation to the origin of the anterior interventricular branch. RESULTS: The diameters of the anterior interventricular branch were as follows: the mean proximal diameter was 2.76±0.76 mm; the mean diameter under the myocardial bridge was 2.08±0.54 mm; and the mean distal diameter was 1.98±0.59 mm. In 33.33% (10/30) of the cases, the diameter of the anterior interventricular branch under the myocardial bridge was lower than the diameter of the anterior interventricular branch distal to the myocardial bridge. In 3.33% (1/30) of the cases, an atherosclerotic plaque was found in the segment under the myocardial bridge. The myocardial bridge was located in the middle third of the anterior interventricular branch in 86.66% (26/30) of the cases. CONCLUSION: Myocardial bridges are more frequently found in the middle third of the anterior interventricular branch of the left coronary artery. The diameter of the anterior interventricular branch of the left coronary artery under the myocardial bridge may be smaller than after the bridge. Myocardial bridges may not provide protection against the formation of atherosclerotic plaque inside the anterior interventricular branch of the left coronary artery.

Effect of arginine vasopressin on the canine epicardial coronary artery: experiments on V1-receptor-mediated production of nitric oxide

OBJECTIVE: To determine whether arginine vasopressin releases endothelium-derived nitric oxide (EDNO) from the epicardial coronary artery. METHODS: We studied segments of canine left circumflex coronary arteries suspended in organ chambers to measure isometric force. The coronary artery segments were contracted with prostaglandin F2alpha (2 x 10-6M) and exposed to a unique, strong arginine vasopressin concentration (10-6M) or titrated concentrations (10-9 a 10-5 M). RESULTS: The unique dose of arginine vasopressin concentration (10-6M) induced transient, but significant (p<0.05), relaxation in arterial segments with endothelium, and an increase, not significant, in tension in arteries without endothelium. Endothelium-dependent relaxation to arginine vasopressin was inhibited by Ng-monomethyl-L-arginine (L-NMMA, 10-5M) or N G-nitro-L-arginine (L-NOARG) (10-4M), 2 inhibitors of nitric oxide synthesis from L-arginine. Exogenous L-arginine (10-4M), but not D-arginine (10-4M), reversed the inhibitory effect of L-NMMA on vasopressin-mediated vasorelaxation. Endothelium dependent relaxation to vasopressin was also reversibly inhibited by the vasopressin V1-receptor blocker d(CH2)5Try(Me) arginine vasopressin (10-6M) (n=6, P<0.05). CONCLUSION: Vasopressin acts through V1 endothelial receptors to stimulate nitric oxide release from L-arginine.

Surgical myocardial revascularization without extracorporeal circulation

OBJECTIVE: To assess the immediate postoperative period of patients undergoing myocardial revascularization without extracorporeal circulation with different types of grafts. METHODS: One hundred and twelve patients, 89 (79.5%) of whom were males, were revascularized without extracorporeal circulation. Their ages ranged from 39 to 85 years. The criteria for indicating myocardial revascularization without extracorporeal circulation were as follows: revascularized coronary artery caliber > 1.5 mm, lack of intramyocardial trajectory on coronary angiography, noncalcified coronary arteries, and tolerance of the heart to the different rotation maneuvers. RESULTS: Myocardial revascularization without extracorporeal circulation was performed in 112 patients. Three were converted to extracorporeal circulation, which required a longer hospital stay but did not impact mortality. During the procedure, the following events were observed: atrial fibrillation in 10 patients, ventricular fibrillation in 4, total transient atrioventricular block in 2, ventricular extrasystoles in 58, use of a device to retrieve red blood cells in 53, blood transfusion in 8, and arterial hypotension in 89 patients. Coronary angiography was performed in 20 patients on the seventh postoperative day when the grafts were patent. CONCLUSION: Myocardial revascularization without extracorporeal circulation is a reproducible technique that is an alternative for treating ischemic heart disease.

Association between coronary artery atherosclerosis and the intima-media thickness of the common carotid artery measured on ultrasonography

OBJECTIVE: To assess whether the intima-media thickness of the common carotid artery of patients with coronary artery disease is greater than that of individuals without that disease. METHODS: Case-control prospective study of prevalence assessing the thickness of the intima and media layers of 29 patients with coronary artery disease and 29 individuals without that disease by using ultrasonography of the carotid arteries. Diabetic patients and those with peripheral artery and cerebral vasculopathies were excluded from the study. RESULTS: The mean age was 51±7.5 years. Fifty-five per cent of the patients were males. Acute myocardial infarction was present in 62%; cardiac catheterization in 72%; saphenous bypass in 5%; and coronary angioplasty in 24%. The intima-media thickness of the common carotid artery in case patients and in control patients was, respectively, 0.81±0.25 mm and 0.62±0.18 mm (P=0.001). CONCLUSION: Intima-media thickness of the common carotid artery was significantly greater in patients with coronary artery disease.

Coinfection with Mycoplasma Pneumoniae and Chlamydia Pneumoniae in ruptured plaques associated with acute myocardial infarction

OBJECTIVE: To study atheromas, Mycoplasma pneumoniae (M. pneumoniae), and Chlamydia pneumoniae (C. pneumoniae). METHODS: C. pneumoniae was studied with immunohistochemistry and M. pneumoniae with in situ hybridization (ISH), in segments of coronary arteries (SCA) as follows: group A - thrombosed ruptured plaques (TRP) of 23 patients who died due to acute myocardial infarction (AMI); group B - 23 nonruptured plaques (NRP) of group A patients; group C - NRP of 11 coronary patients who did not die due to AMI; and group D - 11 SCA from patients with dilated cardiomyopathy or Chagas' disease without atherosclerosis. RESULTS: The mean number of C. pneumoniae+ cells/400x in groups A, B, C, and D was, respectively, 3.3±3.6; 1.0±1.3; 1.2±2.4; and 0.4±0.3; and the percentage of M. pneumoniae area was, respectively, 3.9±3.5; 1.5± 1.6; 0.9±0.9; and 0.4±0.2. More M. pneumoniae and C. pneumoniae were found in of group A than in group B (P<0.01). Good correlation was seen between the area of the vessel and the M. pneumoniae area in the plaque (r = 0.46; P=0.001) and between C. pneumoniae+ cells and CD4+ T lymphocytes (r = 0.42; P<0.01). The number of C. pneumoniae+ cells correlated with CD20+ B cells (r=0.48; P<0.01). CONCLUSION: M. pneumoniae and C. pneumoniae are more frequently found in TRP correlate with the intensity of the inflammation and diameter of the vessel (positive remodeling).

Effects of high glucose concentrations on the endothelial function of the renal microcirculation of rabbits

OBJECTIVE: To assess the acute effects of high glucose concentrations on vascular reactivity in the isolated non diabetic rabbit kidney. METHODS: Rabbits were anaesthetized for isolation of the kidneys. Renal arteries and veins were cannulated for perfusion with Krebs-Henselleit solution and measurement of perfusion pressure. After 3 hours of perfusion with glucose 5,5 mM (control ) and 15 mM, the circulation was submitted to sub maximal precontraction (80% of maximal response) trough continuous infusion of noradrenaline 10 mM. Vascular reactivity was then assessed trough dose-responses curves with endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) vasodilators. The influence of hyperosmolarity was analyzed with perfusion with mannitol 15mM. RESULTS: A significant reduction in the endothelium-dependent vasodilation in glucose 15mM group was observed compared to that in control, but there was no difference in endothelium-independent vasodilation. After perfusion with mannitol 15 mM, a less expressive reduction in endothelium-dependent vasodilation was observed, only reaching significance in regard to the greatest dose of acetylcholine. CONCLUSION: High levels of glucose similar to those found in diabetic patients in the postprandial period can cause significant acute changes in renal vascular reactivity rabbits. In diabetic patients these effects may also occur and contribute to diabetes vascular disease.

Kawasaki disease: involution of giant coronary aneurysms after prolonged anti-inflammatory treatment

The patient is a 5-year-old male with Kawasaki disease, whose involution of giant aneurysms of the left coronary arteries was surprising after a prolonged period of treatment, which lasted 80 uninterrupted days and comprised anti-inflammatory drugs associated with anticoagulation agents. The distal diameters of the anterior interventricular, the diagonal, and the circumflex arteries normalized by the end of the treatment. A residual giant aneurysm localized at the beginning of the anterior interventricular artery did not cause ischemia. Continuation of the medication for a prolonged period was recommended.

Demographic characteristics of the population undergoing cine coronary angiography at the Instituto do Coração of the Medical School of USP from 1986 to 1995

OBJECTIVE: To obtain information about the profile and behavior of a population with ischemic heart disease undergoing cine coronary angiography and to determine disease severity. METHODS: Retrospective study assessing patients hospitalized at InCor from 1986 to 1995, in which the variables age, sex, and number of major coronary arteries with obstruction degree > 40% were analyzed. RESULTS: We studied 18,221 patients and observed a significant increase in the number of females (22.8% to 25.2%, P=0.001) and an increase in age (57.1±29.3 to 60.4±10.7 years, P=0.0001). A significant increase in the incidence of multivessel disease was observed, which was more frequent among males (69.2% and 64.5%) and among the older patients (59.8±9.8 and 56.8±10.7 years, P=0.0001). A reduction in the incidence of single-vessel disease was also observed (66.2% vs 69.2% and 33.8% vs 30.5%, respectively, P<0.0001). CONCLUSION: A change in the profile of the population studied was observed as follows: patients undergoing cine coronary angiography at InCor were older, had a greater number of impaired major coronary arteries, and the number of females affected increased, leading to indices suggestive of a poorer prognosis.

Morphometric and topographic study of coronary ostia

OBJECTIVE: To investigate the morphometric and topographic aspects of coronary ostia, correlating them with the aortic leaflets. METHODS: Fifty-one hearts with the great vessels attached were analyzed in this study. The ascending aorta was transversally sectioned 1 cm above the commissures of the aortic leaflets. The right and left coronary ostia were analyzed, as were the distances from these ostia to the bottom of the aortic sinuses and to the commissures of the aortic leaflets. RESULTS: The left coronary ostium was located below the intercommissural line in 42% of cases, above that line in 40% of cases, and at the level of that line in 18% of cases. The mean distance from the left coronary ostium to the bottom of the corresponding sinus was 12.6±2.61 mm. The right coronary ostium was located below the intercommissural line in 60% of cases, above that line in 28% of cases, and at the level of that line in 12% of cases. The mean distance from the right coronary ostium to the bottom of the corresponding aortic sinus was 13.2±2.64 mm. The mean diameters of the left and right coronary ostia were 4.75±0.93 mm and 3.46±0.94 mm, respectively. The mean diameters of the juxtamural portion of the left and right coronary arteries were 3.75±0.79 mm and 2.9±0.73 mm, respectively. In one case, both ostia were located in the left coronary sinus. CONCLUSION: The left coronary ostium may be located either above or below the intercommissural line. The right coronary ostium is predominantly located below the intercommissural line. The coronary ostia have reduced diameters as compared with the juxtamural diameters of their respective coronary arteries.

Comparison of immediate results and follow-up of patients with single-vessel and multivessel coronary artery disease younger than 50 years of age undergoing coronary stent implantation

OBJECTIVE: To assess the in-hospital results and clinical follow-up of young patients (< 50 years) with multivessel coronary artery disease undergoing stent implantation in native coronary arteries and to compare their results with those of patients with single-vessel coronary artery disease. METHODS: We retrospectively studied 462 patients undergoing coronary stent implantation. Patients were divided into 2 groups: group I (G-I) - 388 (84%) patients with single-vessel coronary artery disease; and group II (G-II) - 74 (16%) patients with multivessel coronary artery disease. RESULTS: The mean age of the patients was 45±4.9 years, and the clinical findings at presentation and demographic data were similar in both groups. The rate of clinical success was 95% in G-I and 95.8% in G-II (P=0.96), with no difference in regard to in-hospital evolution between the groups. Death, acute myocardial infarction, and the need for myocardial revascularization during clinical follow-up occurred in 10.1% and 11.2% (P=0.92) in G-I and G-II, respectively. By the end of 24 months, the actuarial analysis showed an event-free survival of 84.6 % in G-I and 81.1% in G-II (P=0.57). CONCLUSION: Percutaneous treatment with coronary stent implantation in young patients with multivessel disease may be safe with a high rate of clinical success, a low incidence of in-hospital complications, and a favorable evolution in clinical follow-up.

Follow-up study of morphology and cardiac function in rats undergoing induction of supravalvular aortic stenosis

OBJECTIVE: To characterize the follow-up of an experimental model of left ventricular hypertrophy (LVH) induced by supravalvular ascending aortic stenosis in young rats. METHODS: Wistar rats were submitted to thoracotomy and aortic stenosis was created by placing a clip on the ascending aorta (AoS group, n=12). Age-matched control animals underwent a sham operation (C group, n=12). Cardiac function was analysed by echocardiograms performed 6, 12, and 21 weeks after aortic banding. Myocardial morphological features and myocardial hydroxyproline concentration (HOP) were evaluated 2, 6, 12, and 21 weeks after surgery in additional animals. RESULTS: Aortic banding promoted early concentric LVH and a progressive increase in HOP. Under light microscopy, we observed myocyte hypertrophy and wall thickening of the intramural branches of the coronary arteries due to medial hypertrophy. Cardiac function was supranormal after 6 weeks (percentage of fractional shortening - EAo6: 70.3±10.8; C6: 61.3±5.4; p<0.05), and depressed in the last period. Diastolic dysfunction was detected after 12 weeks (ratio of early-to-late filling velocity - EAo12: 4.20±3.25; C12: 1.61±0.16; p<0.05). CONCLUSION: Ascending aortic stenosis promotes concentric LVH with myocardial fibrosis and minimal histological changes. According to the period of evaluation, cardiac function may be improved, normal, or depressed. The model is suitable and useful for studies on pathophysiology and treatment of the different phases of cardiac hypertrophy.

Concentração sérica de lípides e apolipoproteína B em recém-nascidos

OBJETIVO: Determinar numa população de recém-nascidos de uma cidade do sul do Brasil as concentrações de lípides séricos e apolipoproteína B (apo-B) em neonatos normais a termo e pré-termo, analisando-se a influência da idade gestacional e do peso ao nascimento. MÉTODOS: Foram estudados 212 neonatos de ambos os sexos, deles, 142 a termo (>37 semanas de gestação) e 70 neonatos pré-termo (<37 semanas). Os neonatos a termo e pré-termo foram classificados pelo peso de nascimento em pequeno para a idade gestacional ou adequado para a idade gestacional. Utilizou-se o sangue do cordão umbilical para as análises bioquímicas. RESULTADOS: Os valores de colesterol total, LDL-C, HDL-C e de apo-B foram maiores nos neonatos pré-termo (79±34, 26±6, 45±15 e 36±14 mg/dL, respectivamente) do que nos neonatos a termo (58±19, 20±10, 31±14 e 28±7 mg/dL, respectivamente; p < 0,0001). Inversamente, os valores de triglicérides foram menores nos neonatos pré-termo (36±14 mg/dL) do que nos neonatos a termo (43±25 mg/dL; p < 0,0018). O sexo e o fato de o neonato ser pequeno ou adequado para a idade gestacional não influenciaram os valores de colesterol total e frações, de triglicérides e apo-B. CONCLUSÃO: As concentrações de lípides plasmáticos e de apo-B dos neonatos da população estudada são semelhantes às dos neonatos de outros países de continentes diversos reportados na literatura e, como esperado, é acentuadamente menor do que os valores referidos na literatura para as de crianças acima de dois anos. A maturidade fetal influencia a concentração de lípides dos neonatos, mas o peso de nascimento não tem efeito nesses parâmetros.

Diferentes aferições do diâmetro abdominal sagital e do perímetro da cintura na predição do HOMA-IR

FUNDAMENTO: A correlação entre aumento de gordura visceral e de resistência à insulina coloca o diâmetro abdominal sagital e o perímetro da cintura como instrumentos potenciais para a predição de resistência à insulina. OBJETIVO: Avaliar a reprodutibilidade de diferentes aferições do diâmetro abdominal sagital e do perímetro da cintura e analisar o poder discriminante dos mesmos para predizer resistência à insulina. MÉTODOS: Foram avaliados 190 homens adultos. O diâmetro abdominal sagital (menor cintura, maior diâmetro abdominal, nível umbilical e ponto médio entre as cristas ilíacas) e o perímetro da cintura (nível umbilical, menor cintura, imediatamente acima da crista ilíaca e ponto médio entre a crista ilíaca e a última costela) foram aferidos em quatro locais diferentes. A resistência à insulina foi avaliada pelo índice HOMA-IR. RESULTADOS: Todas as medidas apresentaram correlação intraclasse de 0,986-0,999. Tanto o diâmetro abdominal sagital aferido na menor cintura (r=0,482 e AUC=0,739±0,049) como o perímetro da cintura aferido no ponto médio entre a última costela e a crista ilíaca (r=0,464 e AUC=0,746±0,05) apresentaram maiores correlações com o HOMA-IR, bem como um melhor poder discriminante para o HOMA-IR segundo a análise ROC (p<0,001). CONCLUSÃO: O diâmetro abdominal sagital e o perímetro da cintura mostraram-se altamente reprodutíveis. O diâmetro abdominal sagital (menor cintura) e o perímetro da cintura (ponto médio crista ilíaca e última costela) apresentaram melhor desempenho em predizer o HOMA-IR. Investigações em outros grupos da população brasileira devem ser realizadas para viabilizar a utilização desses indicadores de resistência à insulina na população como um todo de forma padronizada.