Doble ruptura miocárdica como complicación mecánica de un infarto agudo / Double myocardial rupture as a mechanical complication of an acute infarction

Resumen Las complicaciones del infarto agudo de miocardio se clasifican en mecánicas, eléctricas, isquémicas, tromboembólicas e inflamatorias; entre las complicaciones mecánicas destaca la ruptura de la pared libre del ventrículo izquierdo, músculos papilares y del septum ventricular, con incidencia menor de 1%, que ha descendido con la introducción de la intervención coronaria percutánea como principal estrategia de reperfusión. Se comunica el caso de una paciente de 64 años de edad, que acudió a urgencias por un cuadro de dolor torácico agudo compatible con síndrome coronario agudo con elevación del segmento ST (SICACEST) y durante su evolución tuvo deterioro clínico, se identificó una doble ruptura miocárdica. Se plantea el abordaje del caso y se revisa la bibliografía, porque una doble ruptura miocárdica corresponde solo a 0.3% de los casos reportados.

Abstract The complications of acute myocardial infarction are classified in mechanical, electrical, ischemic, embolic and inflammatory. The main mechanical complications are free wall rupture, papillary muscle and ventricular septal rupture. Its incidence is less than 1% and has decreased with the introduction of percutaneous coronary intervention as the main reperfusion strategy. This article presents a clinical case of a 64-year-old female that arrived to emergency room with thoracic pain, due to an acute coronary syndrome: ST-elevation myocardial infarction (STEMI); with a clinical deterioration presenting a double myocardial rupture. Clinical approach and bibliographic review are reported, the incidence estimation of this disorder is only 0.3% of the reported clinical cases.

Endocarditis no infecciosa de la válvula mitral asociada con lupus eritematoso sistémico / Non-infectious endocarditis of mitral valve concomitant to systemic lupus erythematosus

Resumen La endocarditis de Libman-Sacks es una forma de endocarditis no infecciosa, caracterizada por vegetaciones estériles que afectan principalmente las válvulas aórtica y mitral. Se asocia con enfermedades como lupus eritematoso sistémico y la manifestación más común es asintomática. Se relaciona con duración de la enfermedad, actividad lúpica y existencia de anticuerpos antifosfolipídicos. El diagnóstico se establece por ecocardiografía transtorácica y el definitivo por estudio de patología que demuestra vegetaciones en la autopsia o en muestras quirúrgicas. Se informa el caso de una paciente de 62 años que acudió por astenia, adinamia, ataque al estado general y disnea de medianos esfuerzos; en la ecocardiografía se encontraron vegetaciones. Se sometió a tratamiento quirúrgico y el diagnóstico se confirmó por estudio de patología.

Abstract Libman-Sacks endocarditis is a nonbacterial thrombotic endocarditis, characterized by the deposition of sterile platelet thrombi on heart valves, aortic and mitral. It is associated with systemic lupus erythematosus and the clinical manifestation is typically asymptomatic. It is associated with disease duration, lupus activity and antiphospholipid antibodies. The diagnosis is by echocardiography and the definitive diagnosis can be made pathologically by the demonstration of vegetations on autopsy or surgical speci mens. This paper reports the case of a 62-year old patient with asthenia, adynamia and dyspnea of medium efforts; the echocardiography showed vegetations and patient was underwent to surgical treatment with resection of vegetations, diagnosis was confirmed by pathology.

Hypercontrols in genotype-phenotype analysis reveal ancestral haplotypes associated with essential hypertension.

The angiotensinogen gene locus has been associated with essential hypertension in most populations analyzed to date. Increased plasma angiotensinogen levels have been proposed as an underlying cause of essential hypertension in whites; however, differences in the genetic regulation of plasma angiotensinogen levels have also been reported for other populations. The aim of this study was to analyze the relationship between angiotensinogen gene polymorphisms and haplotypes with plasma angiotensinogen levels and the risk of essential hypertension in the Mexican population. We genotyped 9 angiotensinogen gene polymorphisms in 706 individuals. Four polymorphisms, A-6, C4072, C6309, and G12775, were associated with increased risk, and the strongest association was found for the C6309 allele (χ(2)=23.9; P=0.0000009), which resulted in an odds ratio of 3.0 (95% CI: 1.8-4.9; P=0.000006) in the recessive model. Two polymorphisms, A-20C (P=0.003) and C3389T (P=0.0001), were associated with increased plasma angiotensinogen levels but did not show association with essential hypertension. The haplotypes H1 (χ(2)=8.1; P=0.004) and H5 (χ(2)=5.1; P=0.02) were associated with essential hypertension. Using phylogenetic analysis, we found that haplotypes 1 and 5 are the human ancestral haplotypes. Our results suggest that the positive association between angiotensinogen gene polymorphisms and haplotypes with essential hypertension is not simply explained by an increase in plasma angiotensinogen concentration. Complex interactions between risk alleles suggest that these haplotypes act as "superalleles."

Variants and haplotypes in angiotensinogen gene are associated with plasmatic angiotensinogen level in Mexican population.

INTRODUCTION: The plasmatic angiotensinogen (AGT) level has been associated with essential hypertension. Linkage analysis has found a relationship between the AGT gene locus and hypertension in the Mexican-American population, but studies have failed to identify genetic variants associated with hypertension or plasma AGT levels. This study analyzes the relationship between polymorphisms in the AGT gene and plasmatic AGT levels in Mexican population. METHODS: Nine polymorphisms in AGT gene were genotyped, and plasma AGT level was determined by enzyme-linked immunosorbent assay. RESULTS: Differences in AGT plasma levels were associated with 2 polymorphisms: T-20G, TT = 25.3 ± 8.3 versus TG + GG = 21.6 ± 8.8 µg/mL; P = 0.008 and C3389T (T174M), CC = 25.8 ± 9.9 versus TC + TT = 20.5 ± 5.4 µg/mL; P = 0.0002. Haplotype 2 was associated with low plasma AGT (-5.1 µg/mL [95% confidence interval: -8.6 to -1.6], P = 0.004) and Haplotype 8 was associated with high plasma AGT (6.5 µg/mL [95% confidence interval: 2.5 to 10.6], P = 0.001). This association remained after adjustment for covariates. A Likelihood Ratio Test for haplotype-phenotype association adjusted for covariates resulted in χ = 38.9, P = 0.0005. The total effect of the haplotypes on plasma AGT level variance was 19.5%. No association was identified between haplotypes and quantitative traits of blood pressure. CONCLUSIONS: Two polymorphisms (T-20G and C3389T) and 2 haplotypes (H2 and H8) showed an association with plasma AGT levels in Mexican population.

Analysis of genomic diversity in Mexican Mestizo populations to develop genomic medicine in Mexico.

Mexico is developing the basis for genomic medicine to improve healthcare of its population. The extensive study of genetic diversity and linkage disequilibrium structure of different populations has made it possible to develop tagging and imputation strategies to comprehensively analyze common genetic variation in association studies of complex diseases. We assessed the benefit of a Mexican haplotype map to improve identification of genes related to common diseases in the Mexican population. We evaluated genetic diversity, linkage disequilibrium patterns, and extent of haplotype sharing using genomewide data from Mexican Mestizos from regions with different histories of admixture and particular population dynamics. Ancestry was evaluated by including 1 Mexican Amerindian group and data from the HapMap. Our results provide evidence of genetic differences between Mexican subpopulations that should be considered in the design and analysis of association studies of complex diseases. In addition, these results support the notion that a haplotype map of the Mexican Mestizo population can reduce the number of tag SNPs required to characterize common genetic variation in this population. This is one of the first genomewide genotyping efforts of a recently admixed population in Latin America.

Efecto protector del dantrolene en las lesiones miocárdicas producidas por la reperfusión post-isquémica / Protective effect of dantrolene in post-ischemic reperfusion myocardial damage

Este estudio muestra que la hidantoína, dantrolene, protege al miocardio de las lesiones ocasionadas por la reperfusión post-isquémica. Este efecto, fue analizado después de ocluir durante 5 minutos la arteria coronaria izquierda de corazones de ratas Wistar. Los resultados evidencian que el dantrolene, a dosis de 1 mg/Kg, es efectivo para proteger al miocardio de las arritmias ventriculares y la disfunción contráctil ocasionadas por la isquemia-reperfusión. Además, disminuye la liberación de las enzimas creatina cinasa y lactato deshidrogenasa al plasma y protege al miocardio del daño estructural. Proponemos que esta acción protectora, puede deberse a un efecto bloqueador del canal liberador de calcio (canal de rianodina) del retículo sarcoplásmico, disminuyendo de este modo la sobrecarga de calcio sarcoplasmico, característico de la lesión por reperfusión