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Biomedical subjects

Maite Vallejo

Publications and source records attributed to Maite Vallejo.

14 recordsLinked to original sources
PubMed2006

Cerebrovascular blood flow during the near syncopal phase of head-up tilt test: a comparative study in different types of neurally mediated syncope.

AIMS: This study analyses the changes in cerebral blood flow (CBF) velocity occurring in the near syncopal phase of head-up tilt test (HUT) to determine whether their appearance during the premonitory symptoms permits the differentiation of the different types of haemodynamic response. METHODS AND RESULTS: Six hundred and nineteen patients aged 35.9 +/- 16.4 with a prior history of syncope (55%) or presyncope (45%) were studied. Head-up tilt test was positive in 585 patients. The test was interrupted before syncope, once hypotension was evident and CBF changed. A vasovagal reaction (VVR) was observed in 245 patients. They had a 59% fall in diastolic CBF velocity, whereas systolic CBF velocity decreased by 12%. Postural orthostatic tachycardia syndrome (POTS) was observed in 82, systolic and diastolic CBF velocity decreased 44 and 60%, respectively. A similar response was observed in 258 patients with the orthostatic intolerance (OI) pattern. No significant changes were observed in the negative group. CONCLUSION: Patients with VVR had changes in CBF velocity, which are different from those presented by patients with POTS and OI pattern. Cerebral blood flow monitoring is useful to increase the yield of HUT and may allow early interruption before syncope occurs, reducing patient discomfort.

Adolescent↗
PubMed2006

Ambient fine particles modify heart rate variability in young healthy adults.

Particulate air pollution has been related with cardiopulmonary morbidity and mortality. Recent studies have shown that an increase in particulate matter (PM)(2.5) ambient concentrations was associated with a decrease in heart rate variability (HRV) in the elderly with cardiovascular conditions, which could increase the risk of death. In order to assess if this association could also be observed in young adults, we studied 40 young healthy residents of the Mexico City Metropolitan Area (MCMA) who underwent 13 h Holter electrocardiographic and PM(2.5) personal monitoring. HRV was evaluated in time domain: the standard deviation of normal RR intervals (SDNN) and the percentage of differences between adjacent normal RR intervals larger than 50 ms (pNN50). In multivariate analysis with mixed effects models, a significant negative association of pNN50 with PM(2.5) accumulative exposure was found. An increase in 30 microg/m(3) of the average PM(2.5) personal exposure in the previous 2 h decreased the pNN50 in 0.08% (P=0.01). This observation revealed an acute effect related to environmental exposure to PM(2.5) with regard to HRV in normal youngsters. The long-term health consequences of this association in young healthy adults remain to be clarified.

Adult↗
PubMed2006

Personal PM2.5 and CO exposures and heart rate variability in subjects with known ischemic heart disease in Mexico City.

Cardiovascular diseases are the main cause of death in Mexico City and have shown a rising trend over the past 20 years. Various epidemiological studies have reported an association between respirable particles and carbon monoxide (CO), with cardiorespiratory outcomes. The purpose of this study was to assess the effect of particulate matter with aerodynamic diameters of less than 2.5 microm (PM(2.5)), also known as respirable or fine particles and CO on heart rate variability (HRV) in 5-min periods in patients with known ischemic heart disease. 30 patients were selected from the outpatient clinic of the National Institute of Cardiology of Mexico and followed during 11 h, using electrocardiography (ECG) ambulatory electrocardiograms and personal monitors for CO and PM(2.5). We calculated frequency-domain measurements using power spectral analysis and assessed the association with pollutants using mixed models analysis in 5-min periods. We found a decrease in HRV measured as high frequency (Ln) (coefficient=-0.008, 95% confidence interval (CI), -0.015, 0.0004) for each 10 microg/m(3) (micrograms per cubic meter) increase of personal PM(2.5) exposure. We also found a decrease of low (ln) (coefficient=-0.024, 95% CI, -0.041, -0.007) and very low frequencies (ln) (coefficient=-0.034, 95% CI, -0.061, -0.007) for 1 parts per million (p.p.m.) increase in CO personal exposure after adjustment for potential confounding factors. These results show that for this high-risk population, the alteration of the cardiac autonomic regulation was significantly associated with both PM(2.5) and CO personal exposures.

Adult↗
PubMed2005

[Epidemiological and clinical outlook of chronic Chagas' heart disease in Mexico].

OBJECTIVE: To compare the epidemiological and clinical characteristics of chronic Chagas' heart disease to other dilated cardiomyopathies. METHODS: A study comprising 128 patients from a heart disease center was carried out from 1993 to 2003. Of them, 51 (40%) were Trypasonoma cruzi positive. Epidemiological data was obtained through interviews and clinical and serological data from health services. Statistic analysis was conducted using the Chi-square, Fischer, Mann-Whitney or Students' t-test as well as multivariate analysis. RESULTS: Chronic Chagas' disease patients were older (55+/-10 years old) than those patients with cardiopathy (42+/-17 years old). Most of them were born in rural areas (90% vs 68%), lived in poor (75% vs 16%), crowded households (45% vs 20%), together with domestic animals (71% vs 61%) and were aware of the Chagas' vector (73% vs 25%). Rhythm and conduction ECG abnormalities as well as permanent pacemaker were common among Chagas' patients (84% vs 55%, 78% vs 64% and 24% vs 10%, respectively). Congestive heart failure was more frequent among cardiomiopathy patients (88% vs 71%). Both groups had abnormal myocardial perfusion with normal epicardial arteries. Comorbidities were more frequent in cardiomiopathy patients than in chronic Chagas' disease patient (two cases only). CONCLUSIONS: Chagas' disease is the most common cause of dilated cardiomiopathy in the study hospital. Due to its regional distribution in Mexico, it deserves special attention and control programs proven to be effective in other countries.

Aged↗
PubMed2005

Age, body mass index, and menstrual cycle influence young women's heart rate variability --a multivariable analysis.

Heart rate variability (HRV) in women has been related independently to endogenous sex hormones, hormone replacement therapy, menopause, menstrual cycle, body mass index (BMI), and physical conditioning. However, the joint influence of all these factors has not been reported. The present study describes the relation between circadian variation HRV and assesses its association with BMI, age, and menstrual cycle in healthy young women. A multivariable analysis was performed to estimate the predictive variables involved in SDNN, pNN50, and rMSSD profile, using the classification and regression tree (CART) and the logistic regression models. It was found that the first predictive variable was age, which divided women in two groups: >29.5 years old and <29.5 years old. In the case of the SDNN, the second predictive variable was BMI; the highest values were observed in women younger than 23 years old, with a BMI less than 19.82 kg/m2 and during the follicular phase of her menstrual cycle. For pNN50 and rMSSD the second predictive variable was menstrual cycle for women younger than 29.5 years old. Thus, in this group of women, age was a major determinant of cardiac autonomic nervous modulation followed by the BMI. HRV may be better understood using a multivariable analysis that could mimic physiological conditions.

Adult↗
PubMed2004

Personal exposure to particulate matter less than 2.5 microm in Mexico City: a pilot study.

This study was aimed to describe the personal exposure of permanent residents in Mexico City's Metropolitan Area (MCMA) to particulate matter of less than 2.5 microm diameter (PM(2.5)) during their daily activities. A total of 40 healthy volunteers (30 women and 10 men) with sedentary activities were included. All of them carried a PM(2.5) personal monitor during 13 h and registered their activities in a written diary that classified them in indoor and outdoor microenvironments in each 30 min period. All sample collections started at 0900 hours, and even though measurements were obtained during the rainy season (April-August 2002), the relative humidity was less than 70%. The data were categorized and evaluated under the following criteria: morning and afternoon exposure, indoor and outdoor activities, and geographical location. The descriptive analysis showed that the overall outdoor median concentration of PM(2.5) (89.50 microg/m(3)) was higher than the indoor one (67.55 microg/m(3)). PM(2.5) concentrations in the morning to early afternoon were more elevated than in the late afternoon, suggesting a circadian-like behavior. In the indoor microenvironment, the highest concentration occurred in the subway (106.2 microg/m(3)) followed by school (93.27 microg/m(3)), and the lowest at home (53.1 microg/m(3)). The outdoor microenvironment with the highest concentrations was the public transportation (bus) (99.95 microg/m(3)), while the automobile had the lowest (64.9 microg/m(3)). The geographical zone with the highest concentration was the Center city area (87.87 microg/m(3)), and the one with the lowest concentration was the northeast area of the city (50 microg/m(3)). All the differences were statistically significant (P<0.05). Multivariate analysis corroborated that PM(2.5) concentrations are mainly determined by geographical locations and hour of the day, but not by the type of microenvironment. The inclusion of covariables in the multivariable analysis ensures a more accurate estimation and prediction of the real PM(2.5) concentrations. In conclusion, PM(2.5) personal exposure of healthy adult permanent residents of MCMA is usually higher than recommended by the international standards in outdoor and even in indoor microenvironments. Particulate matter personal exposure varies in relation to hour of the day, daily activities and microenvironments.

Activities of Daily Living↗
PubMed2002

[Aortic valve complications associated with subarterial infundibular ventricular septal defect. Echocardiograpic follow-up].

INTRODUCTION AND OBJECTIVES: Interventricular fibromuscular septal defects of the outlet tract are subarterial infundibular ventricular septal defects (VSDs). This anatomical situation predisposes to aortic cusp prolapse (AoP) and/or regurgitation (AoR). METHODS: In order to determinate the frequency of VSDs and the presence or development of aortic valve alterations detected by two-dimensional echocardiography, we studied 35 patients with VSDs. The defect area and presence, severity, and evolution of AoP and/or AoR were evaluated. Ten anatomic specimens were studied to verify the echocardiographic correlation. RESULTS: Subarterial infundibular defect was present in 6.9% of all ventricular septal defects. The average age at time of diagnosis was 5,8 years. VSDs diameter and gradient did not change during follow-up. At time of diagnosis, 30 patients (87%) did not have AoR, but during an average follow-up of 8 years, 11 (32%) developed it. By the end of the study, 46% had AoR. When the time to progression of AoR was compared in the group that developed it versus the group that did not, the median values were similar in both groups. There was a greater tendency to development and/or progression of regurgitation in small VSDs. The echo-anatomic correlation was precise. CONCLUSIONS: Aortic valve damage was a frequent finding in VSD. Most cases did not progress to more severe AoR. Small VSDs developed more severe regurgitation in less time. Surgery must be considered when AoR is detected. Regular evaluation by echocardiography is important in follow-up.

Adolescent↗
PubMedDate not supplied

[How much does the medical treatment of chronic Chagas cardiopathy cost? Direct costs in a cardiology hospital].

OBJECTIVE: To estimate health care costs of patients with chronic Chagasic cardiomyopathy (CCC) in a cardiovascular referral center (Instituto Nacional de Cardiología I. Chávez). MATERIAL AND METHODS: In a retrospective study, 13 clinical charts of CCC patients treated in the hospital during 1998 were reviewed. Diagnostic and therapeutic procedures and patients admission were identify as well as health care costs, which were drawn from the hospital costs system. RESULTS: 62% of the cases were admitted to the hospital through the out-patient facilities. All the patients had a health care subsidy of 15 to 55% allocated to the institutional budget. Health care costs were calculated for minimal, average, and maximum scenarios, according to the patient's clinical stage and the price of medical equipment used (low, medium, and high). Most of the health care costs are due to the use of high cost diagnostic equipment (33 a 58%) and hospital stay (including the emergency room) (19 a 28%). CONCLUSION: This is the first approximation to the economic study of Chagas disease in Mexico, providing foundations for further studies on health economics and quality care of CCC, and suggests that prevention should be enhanced.

Adult↗
PubMedDate not supplied

[Effects of air pollution on human health and their importance in Mexico City].

The impact of air pollution on human health is a complicated problem. In this review, we describe the main health effects of exposure to ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, lead and particulate matter. Geographical characteristics of the metropolitan area of Mexico City that favor pollutant persistence with adverse effects on the population are described; the use of the Indice Metropolitano de la Calidad del Aire (IMECA), current norms, and present programs to diminish this problem are discussed. Evidence shows that through these actions, air quality has improved. However, some pollutants such as ozone and particulate matter, still exceed the standard. To further improve air quality in the city, existing programs should continue and multidisciplinary research, both basic and applied, is required.

Air Pollutants↗
PubMedDate not supplied

[Diagnostic evaluation of cardiovascular autonomic function in patients with diabetes mellitus].

Cardiovascular autonomic neuropathy is a common complication of diabetes mellitus. There are several diagnostic methods currently used. New techniques are described. The purpose of this review paper is to describe and analyze the clinical relevance of all this methods and propose an algorithm for the diagnosis of the cardiovascular autonomic neuropathy at daily medical practice.

Autonomic Nervous System↗
PubMedDate not supplied

[Treatment of patent ductus arteriosus. Comparison of costs between surgical and trans-catheter closures in a public institution].

UNLABELLED: The costs of transcatheter closure of patent ductus arteriosus in relation to the surgical closure still a controvertial issue in our hospitals. The aim of the study was compared the costs of both treatments. METHODS: We included 57 patients treated with transcatheter occlusion and 26 underwent surgery. Information about laboratory tests, average in hospital days of stay, anesthesia type and duration, operating and hemodinamic room costs, was gather. A database containing the costs from the institution unitary costs system in force was designed. RESULTS: sociodemographyc characteristics were similar in both groups. Ductus size was larger in patients treated with surgery (p<0.05). In hospital stay, as well as, the number of complications after the procedure were less in the patients treated with transcatheter occlusion (p<0.05). The closure with Amplatzer device was more expensive than the surgical one, and both were more expensive than coil. With surgical treatment, 86.5% of the costs are due to in hospital stay, with the Amplatzer this issues represented a 36%, however, the cost of the devices by itself represents a 40% of the total treatment cost. CONCLUSIONS: Even though total charges of Amplatzer devices are more expensive than surgery, transcatheter occlusion represents advantages in relation to less in hospital stay, resources used and number of complications, which allows hospital resources optimization.

Cardiac Catheterization↗
PubMedDate not supplied

[Chronic Chagasic Cardiomyopathy at the Hospital General de Zona no. 24 IMSS. Poza Rica, Veracruz].

UNLABELLED: Northern Veracruz has conditions, biotic and abiotic, to support Triatomine bugs and vectorial transmission of Trypanosoma cruzi to human beings. Therefore we explore seroprevalence of antibodies to this parasite and the presence of Chronic Chagasic Cardiopathy (CCC) at Cardiology ward in a General Hospital serving North of Veracruz State, and neighbord states Hidalgo, Puebla San Luis Potosi and Tamaulipas. MATERIAL AND METHODS: We search for consecutive adult patients attending outpatient and beds assigned to Cardiology between March through September, 2003. An epidemiology questionnaire, clinical work up, chest roentgenogram, 12 lead peripheral EKG and transthoracic echocardiogram were performed in 240 female/males patients. All of them were bled to blindly search for T. cruzi antibodies. RESULTS: Seroprevalence was 8%, 49 cases of dilated cardiomyopathy were diagnosed 23 attributed to chronic diseases such as systemic hypertension diabetes mellitus or ischemic heart disease 12 with idiopathic disease and 14 (29%) had CCC. The latter accumulated epidemiologic features suggestive of vectorial infection. Four additional individuals without CCC but having specific antibodies were considered indeterminate Chagasic cases. DISCUSSION AND CONCLUSIONS: This case series identify American Trypanosomiasis among 19 people attending a Cardiology Service, and 14 of them had a severe heart disease linked to progressive and fatal course. This observation points out that Chagas disease could be a regional public health problem in Northern Veracruz.

Adolescent↗
PubMedDate not supplied

[Differences in cardiac autonomic modulation between women and men].

Gender differences in cardiac autonomic modulation are a controversial topic in several studies. The aim of this study, was to describe and compare the heart rate variability in 30 women and 20 men, Mexicans, between 21 to 36 years of age. A 20 to 24 hours Holter monitoring was performed in all of them. Analysis of time (SDNNN and rMSSD), and frequency domains (HF, LF and LF/HF in absolute values and normalized units) were used. SDNN[IBM1] was significantly higher in men. When adjusted for age, there was a negative correlation in parasympathetic activity indexes (rMSSD and HF) in women. Physical training increased SDNN in men and HF in women. The increased parasympathetic activity found in women with physical training diminishes with age. These results demonstrate differences in cardiovascular autonomic modulation between women and men.

Adult↗