Aproximación hacia la evaluación de la aptitud clínica en residentes de cardiología. Diseño multicéntrico / Approach to cardiology residents clinical aptitude evaluation. Multicenter design

Resumen Introducción: Hasta donde se tiene conocimiento, la investigación que se presenta constituye el primer trabajo multicéntrico en México que estudia el desarrollo de la aptitud clínica en unidades formadoras de cardiólogos. Objetivo: Determinar el grado de desarrollo de la aptitud clínica en residentes de cardiología en tres unidades médicas de alta especialidad. Métodos: Diseño transversal multicéntrico. Se analizaron todos los estudiantes del ciclo académico 2019-2020. Se construyó un instrumento que evaluó la aptitud clínica a partir de ocho indicadores y 170 ítems; la validez conceptual/de contenido y la confiabilidad fueron valoradas por cinco cardiólogos con experiencia docente y en investigación educativa. Resultados: Por indicador y año de residencia se observaron diferencias estadísticas significativas en la sede CMN20Nov; en HCSXXI e INCICh se observaron diferencias estadísticamente significativas en uno de ocho indicadores. Se estimaron diferencias entre residentes R1 (n = 41) de las tres sedes por indicador, con significación estadística en tres de ocho indicadores. El resultado fue semejante al comparar R2 (n = 35) y R3 (n = 43). Conclusiones: El grado de desarrollo de la aptitud clínica se puede considerar medio en las tres sedes académicas, probablemente debido a que el instrumento exploró situaciones clínicas problematizadas que exigieron del residente la reflexión crítica de su experiencia clínica.

Abstract Introduction: To the best of our knowledge, the research herein presented is the first multicenter study in Mexico to analyze the development of clinical aptitude in medical units that train cardiologists. Objective: To determine the degree of development of clinical aptitude in cardiology residents at three High Specialty Medical Units. Methods: Multicenter, cross-sectional design. All students of the 2019-2020 academic year were included in the study. An instrument was constructed that evaluated clinical aptitude based on eight indicators and 170 items; conceptual/content validity and reliability were assessed by five cardiologists with teaching and educational research experience. Results: By indicator and year of residence, significant statistical differences were observed in the CMN20Nov academic site. At HCSXXI and INCICh, statistically significant differences were observed in one of eight indicators. Differences between R1 residents (n = 41) of all three academic sites were estimated by indicator, with statistical significance being recorded in three of eight indicators. Between R2 (n = 35) and between R3 residents (n = 43), the result was similar. Conclusions: The degree of clinical aptitude development can be considered intermediate in all three academic sites, probably because the instrument explored problematized clinical situations that required the residents to critically reflect on their clinical experience.

Approach to cardiology residents clinical aptitude evaluation. Multicenter design.

INTRODUCTION: To the best of our knowledge, the research herein presented is the first multicenter study in Mexico to analyze the development of clinical aptitude in medical units that train cardiologists. OBJECTIVE: To determine the degree of development of clinical aptitude in cardiology residents at three High Specialty Medical Units. METHODS: Multicenter, cross-sectional design. All students of the 2019-2020 academic year were included in the study. An instrument was constructed that evaluated clinical aptitude based on eight indicators and 170 items; conceptual/content validity and reliability were assessed by five cardiologists with teaching and educational research experience. RESULTS: By indicator and year of residence, significant statistical differences were observed in the CMN20Nov academic site. At HCSXXI and INCICh, statistically significant differences were observed in one of eight indicators. Differences between R1 residents (n = 41) of all three academic sites were estimated by indicator, with statistical significance being recorded in three of eight indicators. Between R2 (n = 35) and between R3 residents (n = 43), the result was similar. CONCLUSIONS: The degree of clinical aptitude development can be considered intermediate in all three academic sites, probably because the instrument explored problematized clinical situations that required for the residents to critically reflect on their clinical experience.

INTRODUCCIÓN: Hasta donde se tiene conocimiento, la investigación que se presenta constituye el primer trabajo multicéntrico en México que estudia el desarrollo de la aptitud clínica en unidades formadoras de cardiólogos. OBJETIVO: Determinar el grado de desarrollo de la aptitud clínica en residentes de cardiología en tres unidades médicas de alta especialidad. MÉTODOS: Diseño transversal multicéntrico. Se analizaron todos los estudiantes del ciclo académico 2019-2020. Se construyó un instrumento que evaluó la aptitud clínica a partir de ocho indicadores y 170 ítems; la validez conceptual/de contenido y la confiabilidad fueron valoradas por cinco cardiólogos con experiencia docente y en investigación educativa. RESULTADOS: Por indicador y año de residencia se observaron diferencias estadísticas significativas en la sede CMN20Nov; en HCSXXI e INCICh se observaron diferencias estadísticamente significativas en uno de ocho indicadores. Se estimaron diferencias entre residentes R1 (n = 41) de las tres sedes por indicador, con significación estadística en tres de ocho indicadores. El resultado fue semejante al comparar R2 (n = 35) y R3 (n = 43). CONCLUSIONES: El grado de desarrollo de la aptitud clínica se puede considerar medio en las tres sedes académicas, probablemente debido a que el instrumento exploró situaciones clínicas problematizadas que exigieron del residente la reflexión crítica de su experiencia clínica.

COVID-19 and the renin, angiotensin, aldosterone system. A complex relationship.

The COVID-19 pandemic has had major negative health, psychological, social and economic repercussions for individuals, families, communities, countries and for humanity in general. The interrelation with age and the presence of chronic non-communicable diseases (hypertension, diabetes, obesity, smoking) seems to go further than what would be explained by the prevalence and distribution of both. The drugs that act on the renin-angiotensin-aldosterone system are in many cases the backbone for the management of these diseases, it has been known for a long time that these drugs significantly increase the expression of receptors for angiotensin conversion enzyme type 2 in the lung tissue. This fact, together with the knowledge that the route of entry of the virus into the cell is precisely the ACE-2 receptor, initiated a hypothesis, based on very low-quality evidence, which quickly became generalized in the media, that the use of these drugs could be negative and that they should be interrupted immediately. The response of practically all Scientific Societies was almost immediate, with the precise indication that treatment with these drugs should not be discontinued, since the evidence of their usefulness is based on very solid and high-quality evidence. Simultaneously, a different hypothesis also appeared, also based on very preliminary evidence, that these drugs are not only harmful but also beneficial, however these medicaments are not yet accepted as agents for the prevention or treatment of this disease or its complications. This review reports current knowledge on the relationship between COVID-19 and SRAA.

La pandemia por COVID-19 ha tenido muy importantes repercusiones negativas, sanitarias, psicológicas, sociales y económicas para las personas, las familias, las comunidades, los países y para las para la humanidad en general. La interrelación con la edad y la presencia de enfermedades crónicas no trasmisibles (hipertensión, diabetes, obesidad, tabaquismo) parece ir mas lejos que lo que explicaría la prevalencia y distribución de ambas. Los medicamentos que actúan sobre el sistema renina-angiotensina-aldosterona, son pilares básicos en el manejo de estas enfermedades. Se sabe de tiempo atrás que estos fármacos aumentan en forma significativa la expresión en el tejido pulmonar de receptores para la enzima de conversión de angiotensina de tipo 2. Este hecho junto con el conocimiento de que la vía de entrada del virus a la célula es precisamente el receptor de ECA-2, inició una hipótesis, basada en evidencia de muy baja calidad, que rápidamente se generalizó en los medios de comunicación, de que el empleo de estos medicamentos podría ser negativo y que deberían suspenderse. La respuesta de prácticamente todas las sociedades científicas fue casi inmediata, con la indicación precisa de que no debería suspenderse el tratamiento con estos fármacos, puesto que la evidencia de su utilidad está basada en una evidencia muy sólida y de gran calidad. Casi simultáneamente también apareció la hipótesis, también basada en evidencia muy preliminar, de que estos medicamentos no solo resultan dañinos sino que son benéficos, tampoco se aceptan todavía como agentes para la prevención o tratamiento de esta enfermedad o sus complicaciones. La presente revisión relata los conocimientos actuales sobre la relación entre COVID-19 y SRAA.

Central blood pressure and vascular stiffness in Mexican population / Presión central aórtica y rigidez vascular en mexicanos

Abstract Introduction: Central blood pressure (CBP) is considered a measure of prognostic value for cardiovascular risk. In turn, the aortic pulse wave velocity (PWVAo) and augmentation index (Aix) have been related to arterial stiffness and cardiovascular risk. Controversies exist regarding the reference values in different ethnic groups, ages, and anthropometrics. The objective of this study is to evaluate the CBP and arterial stiffness parameters in a Mexican population by age, gender, and anthropometry. Methods: Between 2015 and 2016, 1009 apparently healthy subjects were recruited in the Instituto Nacional de Cardiología Ignacio Chávez. Using the Arteriograph (TensioMed) equipment with an oscillometric technique, CBP, central pulse pressure (cPP), PWVAo, and Aix were acquired. All results were automatically obtained by computer software version 3.0.0.4. Results: Female sex was prevalent (72%), mean age was 47 ± 12 years; 26% had normal weight, 43% were overweight, and 30% had obesity. The reference values were higher than those reported in other populations. PWVAo and Aix were always found to be higher in females. A central-brachial pressure gradient was observed in < 40 years with lower CBP. Body mass index (BMI) presented a direct and positive correlation with CBP (p < 0.001); however, PWVAo and Aix were not modified. Conclusion: CBP, cPP, PWVAo, and Aix parameters should be considered based on age, gender, and BMI. In Mexican population, CBP and cPP values were higher compared with other previously reported values, especially in women, the elderly, and obese. PWVAo and Aix are higher in older women; however, they are not modified by BMI.

Resumen Introducción: La presión central aórtica (PCA) se considera una medida del valor pronóstico. A su vez, la velocidad de la onda del pulso aórtico (VOPA) y el índice de aumento (IA) se han relacionado con la rigidez arterial y riesgo cardiovascular. Existen controversias sobre los valores de referencia en diferentes grupos. El objetivo de este estudio es evaluar estos parámetros en una población mexicana por edad, género y antropometría. Métodos: Entre 2015 y 2016 se reclutaron 1,009 sujetos aparentemente sanos en el Instituto Nacional de Cardiología Ignacio Chávez. Usando el equipo de Arteriograph (TensioMed) con técnica oscilométrica, se adquirieron: PCA, presión de pulso central, VOPA e IA. Todos los resultados fueron obtenidos automáticamente. Resultados: El sexo femenino fue prevalente (72%), edad de 47 ± 12 años; 26% con peso normal, 43% con sobrepeso y 30% con obesidad. Todos los valores fueron superiores a los reportados en otras poblaciones. VOPA e IA siempre fueron más altos en mujeres. Se observó un gradiente de presión central-braquial en < 40 años, con menor PCA. El IMC presentó una correlación directa y positiva con la PCA (p < 0,001), sin embargo, VOPA e IA no se modificaron. Conclusión: Los parámetros de PCA, VOPA e IA deben considerarse en función de edad, género e IMC. En una población mexicana, los valores de PCA fueron más altos en comparación con informados previamente (Europa y Asia), especialmente en mujeres, ancianos y obesos. VOPA e IA son más altos en mujeres mayores; sin embargo, no son modificados por el IMC.

Central blood pressure and vascular stiffness in Mexican population.

Introduction: Central blood pressure (CBP) is considered a measure of prognostic value for cardiovascular risk. In turn, the aortic pulse wave velocity (PWVAo) and augmentation index (Aix) have been related to arterial stiffness and cardiovascular risk. Controversies exist regarding the reference values in different ethnic groups, ages, and anthropometrics. The objective of this study is to evaluate the CBP and arterial stiffness parameters in a Mexican population by age, gender, and anthropometry. Methods: Between 2015 and 2016, 1009 apparently healthy subjects were recruited in the Instituto Nacional de Cardiología Ignacio Chávez. Using the Arteriograph (TensioMed) equipment with an oscillometric technique, CBP, central pulse pressure (cPP), PWVAo, and Aix were acquired. All results were automatically obtained by computer software version 3.0.0.4. Results: Female sex was prevalent (72%), mean age was 47 ± 12 years; 26% had normal weight, 43% were overweight, and 30% had obesity. The reference values were higher than those reported in other populations. PWVAo and Aix were always found to be higher in females. A central-brachial pressure gradient was observed in < 40 years with lower CBP. Body mass index (BMI) presented a direct and positive correlation with CBP (p < 0.001); however, PWVAo and Aix were not modified. Conclusion: CBP, cPP, PWVAo, and Aix parameters should be considered based on age, gender, and BMI. In Mexican population, CBP and cPP values were higher compared with other previously reported values, especially in women, the elderly, and obese. PWVAo and Aix are higher in older women; however, they are not modified by BMI.

Introducción: La presión central aórtica (PCA) se considera una medida del valor pronóstico. A su vez, la velocidad de la onda del pulso aórtico (VOPA) y el índice de aumento (IA) se han relacionado con la rigidez arterial y riesgo cardiovascular. Existen controversias sobre los valores de referencia en diferentes grupos. El objetivo de este estudio es evaluar estos parámetros en una población mexicana por edad, género y antropometría. Métodos: Entre 2015 y 2016 se reclutaron 1,009 sujetos aparentemente sanos en el Instituto Nacional de Cardiología Ignacio Chávez. Usando el equipo de Arteriograph (TensioMed) con técnica oscilométrica, se adquirieron: PCA, presión de pulso central, VOPA e IA. Todos los resultados fueron obtenidos automáticamente. Resultados: El sexo femenino fue prevalente (72%), edad de 47 ± 12 años; 26% con peso normal, 43% con sobrepeso y 30% con obesidad. Todos los valores fueron superiores a los reportados en otras poblaciones. VOPA e IA siempre fueron más altos en mujeres. Se observó un gradiente de presión central-braquial en < 40 años, con menor PCA. El IMC presentó una correlación directa y positiva con la PCA (p < 0,001), sin embargo, VOPA e IA no se modificaron. Conclusión: Los parámetros de PCA, VOPA e IA deben considerarse en función de edad, género e IMC. En una población mexicana, los valores de PCA fueron más altos en comparación con informados previamente (Europa y Asia), especialmente en mujeres, ancianos y obesos. VOPA e IA son más altos en mujeres mayores; sin embargo, no son modificados por el IMC.

COVID-19 y el sistema renina, angiotensina, aldosterona. Una relación compleja / COVID-19 and the renin, angiotensin, aldosterone system. A complex relationship

Resumen La pandemia por COVID-19 ha tenido muy importantes repercusiones negativas, sanitarias, psicológicas, sociales y económicas para las personas, las familias, las comunidades, los países y para las para la humanidad en general. La interrelación con la edad y la presencia de enfermedades crónicas no trasmisibles (hipertensión, diabetes, obesidad, tabaquismo) parece ir mas lejos que lo que explicaría la prevalencia y distribución de ambas. Los medicamentos que actúan sobre el sistema renina-angiotensina-aldosterona, son pilares básicos en el manejo de estas enfermedades. Se sabe de tiempo atrás que estos fármacos aumentan en forma significativa la expresión en el tejido pulmonar de receptores para la enzima de conversión de angiotensina de tipo 2. Este hecho junto con el conocimiento de que la vía de entrada del virus a la célula es precisamente el receptor de ECA-2, inició una hipótesis, basada en evidencia de muy baja calidad, que rápidamente se generalizó en los medios de comunicación, de que el empleo de estos medicamentos podría ser negativo y que deberían suspenderse. La respuesta de prácticamente todas las sociedades científicas fue casi inmediata, con la indicación precisa de que no debería suspenderse el tratamiento con estos fármacos, puesto que la evidencia de su utilidad está basada en una evidencia muy sólida y de gran calidad. Casi simultáneamente también apareció la hipótesis, también basada en evidencia muy preliminar, de que estos medicamentos no solo resultan dañinos sino que son benéficos, tampoco se aceptan todavía como agentes para la prevención o tratamiento de esta enfermedad o sus complicaciones. La presente revisión relata los conocimientos actuales sobre la relación entre COVID-19 y SRAA.

Abstract The COVID-19 pandemic has had major negative health, psychological, social and economic repercussions for individuals, families, communities, countries and for humanity in general. The interrelation with age and the presence of chronic non-communicable diseases (hypertension, diabetes, obesity, smoking) seems to go further than what would be explained by the prevalence and distribution of both. The drugs that act on the renin-angiotensin-aldosterone system are in many cases the backbone for the management of these diseases, it has been known for a long time that these drugs significantly increase the expression of receptors for angiotensin conversion enzyme type 2 in the lung tissue. This fact, together with the knowledge that the route of entry of the virus into the cell is precisely the ACE-2 receptor, initiated a hypothesis, based on very low-quality evidence, which quickly became generalized in the media, that the use of these drugs could be negative and that they should be interrupted immediately. The response of practically all Scientific Societies was almost immediate, with the precise indication that treatment with these drugs should not be discontinued, since the evidence of their usefulness is based on very solid and high-quality evidence. Simultaneously, a different hypothesis also appeared, also based on very preliminary evidence, that these drugs are not only harmful but also beneficial, however these medicaments are not yet accepted as agents for the prevention or treatment of this disease or its complications. This review reports current knowledge on the relationship between COVID-19 and SRAA.

Echocardiographic correlates of severe pulmonary hypertension in adult patients with ostium secundum atrial septal defect.

OBJECTIVE: To identify echocardiographic factors that correlate with pulmonary hypertension (PH) in adults with ostium secundum atrial septal defect (ASD). METHODS: Between November 2009 and November 2013, 92 adults with ASD were studied. All had clinical history and transthoracic echocardiogram. RESULTS: Thirty-nine percent of patients had severe PH defined as systolic pulmonary artery pressure (sPAP) of 70 mm Hg or more. The size of ASD (31.84±8.21 mm) and a right-sided tricuspid inflow E-wave to tissue Doppler e'-wave ratio >6.2 correlated with severe PH with AUC of 0.704 (CI 95%=0.59 to 0.818, P<.001) and 0.65 (CI 95%=0.531 to 0.773, P<.014), respectively. Multivariate logistic regression showed that sPAP >70 mm Hg was the variable that most precisely correlated with right ventricular (RV) dysfunction as evidenced by TAPSE <17 mm and RV fractional shortening area (RVFSA) <35%. Left ventricular (LV) diastolic function was also significantly reduced in the group with severe PH with mitral inflow E/A ratio of 0.73±0.23 vs 1.13±0.42 in the group without severe PH (sPAP <70 mm Hg, (P=.001). The pulmonary (Qp) to systemic (Qs) cardiac output ratio (3.09±1.12) and right-sided tissue Doppler S <9.5 cm/s most accurately predicted a Tei index >0.55. CONCLUSIONS: Larger size of ASD using the QP/QS ratio and increased right-sided tricuspid E/e' ratio correlated with severe PH with a sPAP of 70 mm Hg or more. Patients with severe PH had more severe RV dysfunction as evaluated by TAPSE and RVFSA in comparison to those with PH <70 mm Hg. LV diastolic function was also reduced in the severe PH group.

Heart rate and use of ß-blockers in Mexican stable outpatients with coronary artery disease.

OBJECTIVE: To evaluate the use of ß-blockers and to monitor heart rate in Mexican patients with coronary artery disease. METHODS: CLARIFY is an outpatients registry with stable CAD. A total of 33,283 patients from 45 countries were enrolled between November 2009 and July 2010 from which 1342 were Mexican patients. RESULTS: The mean HR pulse was 70 bpm (beats per minute). Patients in Mexico were compared with the remaining global CLARIFY population. Patients in Mexico had a higher incidence of acute myocardial infarction and percutaneous coronary intervention, and lower incidence of revascularization surgery compared with the remaining CLARIFY population. More often, Mexican patients presented with diabetes, but less often hypertension and stroke. These patients were split into three mutually exclusive groups of HR ≤ 60 (N=263), HR 61-69 (N=356) and HR ≥ 70 (N=722). Patients with elevated HR had a higher incidence of diabetes and higher diastolic blood pressure on average than those with controlled HR. Regarding the use of ß-blockers, they were used in 63.3% of patients, 2.7% showed intolerance or contraindication to treatment to monitor heart rate, and ivabradine was used in 2.3%. Out of approximately 849 patients receiving treatment of ß-blockers, 52.1% had ≥ 70 bpm HR. CONCLUSIONS: In a large proportion of Mexican patients with stable coronary disease the HR remain elevated, > 70 bpm, even with the use of ß-blockers; this requires further attention.

[Aortic valve calcification evaluated by echocardiography associated with baseline conduction abnormalities as a predictor for pacemaker placement after aortic valve replacement]. / La extension de la calcificación aórtica evaluada mediante ecocardiografia asociada a trastornos de la conducción como predictors de marcapasos dedinitivos en el postoperatorio de cambio valvular aórtico.

INTRODUCTION: Aortic valve replacement in patients with severe aortic stenosis may be complicated by complete atrioventricular block (CAVB), requiring a permanent pacemaker (PPM) implantation. Predicting this complication could help to plan the surgical. OBJECTIVE: Determine whether electrocardiography and echocardiography are useful methods for predicting the need for PPM. MATERIAL AND METHODS: A retrospective, observational and transversal study was performed. An echocardiography based semi-quantitative classification was implemented to graduate the extent of calcification of the aortic valve. RESULTS: We included 95 patients; 10 of them required PPM implantation (10.52%). In the pre-surgical basal electrocardiogram we observed that 90% of patients that required PPM had conduction abnormalities as opposed to only 24.7% in the other group, p = 0.001. A 1st and 2nd degree AV block (AVB 1 and 2) was identified in 8 patients that subsequently needed PPM (80%) vs. 5 patients (5.9%), in the group that did not required it, p = 0.001.OR 41.7, IC 95% 6.5-68. We found a grade 3 calcification extent in 80% of patients who required PPM implant compared with only 17.6% of patients in the other group, p = 0.04, OR 4.8, IC 95% 0.76-29. The AVB 1 and 2 were the single predictor in multivariate analysis but the calcification 3 + AVB 1 and 2, increased sensibility. CONCLUISON: In patients with aortic stenosis in whom aortic valve replacement was performed, identifying AVB 1 and 2 on the basal electrocardiogram is a useful tool in order to identify requirement of PPM. The grade 3 of calcification extent increased the sensibility of this prediction.

Actividades paraoxonasa y arilesterasa bajas en sujetos mexicanos con enfermedad arterial coronaria / Low paraoxonase and arylesterase plasma activities in mexican patients with coronary artery disease

PURPOSE: To determine the Paraoxonase-1 (PON1) activity as well as its pheno- and genotypes at position 192 in Mexican subjects with diagnosis of coronary heart disease (CHD). METHODS: We determined the PON1-192 polymorphism by PCR-RFLP, and serum PON1 activity, using either paraoxon (PONase activity) or phenylacetate (ARE activity) as substrates, in 155 clinically healthy individuals (control group), and 155 patients with at least one myocardial infarction (CHD group). The biochemical A/B phenotype was determined by the ratio of the NaCI 1 M-stimulated PONase activity divided by the ARE activity. RESULTS: We found significantly lower PONase and ARE activities in CHD patients as compared to controls (233.1 +/- 102.1 vs. 295.8 +/- 159.1 nmol/min/mL, and 103.1 +/- 33.7 vs 220.2 +/- 120.7 micromol/min/mL, respectively, p<0.05 for both). Allele and genotype frequencies for PON1-192 were similar in CHD patients and healthy controls. Moreover, in the control group, the PON1-192 Q/R genotype did not matched with the A/B phenotype as has been proposed by other studies. CONCLUSIONS: There were important differences in the ARE and PONase activities between Mexican CHD patients and controls, suggesting that PON1 activity could be a good marker of CHD risk, whereas PON1-192 lacks of value to assess such risk.

[Low paraoxonase and arylesterase plasma activities in Mexican patients with coronary artery disease]. / Actividades paraoxonasa y arilesterasa bajas en sujetos mexicanos con enfermedad arterial coronaria.

PURPOSE: To determine the Paraoxonase-1 (PON1) activity as well as its pheno- and genotypes at position 192 in Mexican subjects with diagnosis of coronary heart disease (CHD). METHODS: We determined the PON1-192 polymorphism by PCR-RFLP, and serum PON1 activity, using either paraoxon (PONase activity) or phenylacetate (ARE activity) as substrates, in 155 clinically healthy individuals (control group), and 155 patients with at least one myocardial infarction (CHD group). The biochemical A/B phenotype was determined by the ratio of the NaCI 1 M-stimulated PONase activity divided by the ARE activity. RESULTS: We found significantly lower PONase and ARE activities in CHD patients as compared to controls (233.1 +/- 102.1 vs. 295.8 +/- 159.1 nmol/min/mL, and 103.1 +/- 33.7 vs 220.2 +/- 120.7 micromol/min/mL, respectively, p<0.05 for both). Allele and genotype frequencies for PON1-192 were similar in CHD patients and healthy controls. Moreover, in the control group, the PON1-192 Q/R genotype did not matched with the A/B phenotype as has been proposed by other studies. CONCLUSIONS: There were important differences in the ARE and PONase activities between Mexican CHD patients and controls, suggesting that PON1 activity could be a good marker of CHD risk, whereas PON1-192 lacks of value to assess such risk.

[Endothelial function]. / Función endotelial.

The endothelium is the first line of tissue whose function is affected by the cardiovascular risk factors. The normal function of this vascular covering maintains the homeostasis of the vascular bed and its alterations favors the appearance of the initial lesions of various diseases including the atherosclerotic process. The endothelial function can be measured by means of non invasive methods and these measures can identify the people at higher risk to develop atherosclerosis and its complications and also the methodology has proven to be useful in the evaluation of the outcomes related to the therapeutic measures. The possibility of performing this methods in a safe, non invasive and reproducible way permits that the endothelial function could be used as screening tool for cardiovascular risk in open population.

Función endotelial / Endothelial function

The endothelium is the first line of tissue whose function is affected by the cardiovascular risk factors. The normal function of this vascular covering maintains the homeostasis of the vascular bed and its alterations favors the appearance of the initial lesions of various diseases including the atherosclerotic process. The endothelial function can be measured by means of non invasive methods and these measures can identify the people at higher risk to develop atherosclerosis and its complications and also the methodology has proven to be useful in the evaluation of the outcomes related to the therapeutic measures. The possibility of performing this methods in a safe, non invasive and reproducible way permits that the endothelial function could be used as screening tool for cardiovascular risk in open population.

Edema pulmonar de las alturas. Consideraciones fisiopatológicas : a propósito de un caso / High altitude pulmonary edema. Physiopathological considerations regarding one case

Uno de los problemas médicos de la altitud lo constituye el Edema Pulmonar de las Alturas (EPA). Generalmente este se presenta en personas que ascienden sin aclimatación a más de 2500 mt de altura sobre el nivel del mar ó en los residentes de altitudes mayores a 3000 mt que descienden por periodos cortos de tiempo a nivel del mar y regresan a su lugar de residencia. A pesar de que se han informado decenas de casos se desconoce su etiopatogenia si bien se han implicado en la genesis factores tanto hidrostráticos como de permeabilidad vascular. En este trabajo presentamos el primer caso de EPA descrito en la literatura nacional y se revisan los factores implicados en su fisiopatología.