Assuntos
Síndrome Metabólica , Obesidade , Saúde Pública , Adolescente , Criança , Humanos , Síndrome Metabólica/complicações , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/prevenção & controle , Síndrome Metabólica/terapia , México , Obesidade/complicações , Obesidade/epidemiologia , Obesidade/prevenção & controle , Obesidade/terapiaAssuntos
Adolescente , Criança , Humanos , Síndrome Metabólica , Obesidade , Saúde Pública , México , Síndrome Metabólica , Síndrome Metabólica , Síndrome Metabólica , Síndrome Metabólica , Obesidade , Obesidade , Obesidade , ObesidadeRESUMO
OBJECTIVE: To assess the ability of the body mass index (BMI) to detect obesity-associated morbidity in subjects with a normal or short stature. METHODS: Information was obtained on 119 975 subjects from a cardiovascular risk factors detection program. Standardized questionnaires were used. Capillary glucose and cholesterol concentrations were measured. Diabetes, arterial hypertension and hypercholesterolemia were selected as end points. Sensitivity, specificity and the likelihood ratio for several BMI thresholds were calculated. ROC curves were constructed to identify the BMI cutoff points with best diagnostic performance. The area under the curve (AUC) was used to assess the proficiency of BMI. RESULTS: Short stature (height
Assuntos
Estatura , Índice de Massa Corporal , Obesidade/fisiopatologia , Adulto , Idoso , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Humanos , Hipertensão/complicações , Hipertensão/fisiopatologia , Funções Verossimilhança , Masculino , México , Pessoa de Meia-Idade , Obesidade/complicações , Curva ROC , Sensibilidade e EspecificidadeRESUMO
A fundamental structural event in the progression of heart failure is myocardial remodeling. New mechanisms have been identified to be related with the cellular and molecular process of remodeling. The interaction between the multiple intracellular and extracellular signaling pathways have been recognized to be crucial for understanding the mechanisms that lead to the transition between cardiac hypertrophy and heart failure. Thus, the goal of this review is to summarize recent findings regarding the molecular and cellular mechanisms involved in the failing heart. The role of apoptosis, extracellular matrix, biochemical and molecular changes, signaling pathways, cytokines, inflammatory response and gene expression are discussed as well as the new possible alternatives for therapy.
Assuntos
Insuficiência Cardíaca/patologia , Doença Aguda , Doença Crônica , Progressão da Doença , Espaço Extracelular , HumanosRESUMO
Simultaneous right and left ventricular function curves (VFC, R, L) were obtained in a canine model, (open chest preparation), with and without pericardium. Preload and afterload conditions for the right and left ventricles were controlled. VFC were constructed from zero to 25 mmHg of ventricular end-diastolic pressures and by increasing the cardiac output from 50 to 250 mL/kg-1min-1. Both, right and left VFC showed an initial steep rise at low filling pressures and then flattened off to a plateau at high filling pressures. The best mathematical model that fitted with the VFC, with and without the pericardium was the parabola (r2 = 0.71, 0.72 respectively). After pericardiectomy R and L VFC were displaced to the left of the VFC with pericardium and a decrease in filling pressures were noted at the same points of cardiac output, findings that suggest a restraining effect of the pericardium. By subtracting the filling pressures obtained with pericardium from those without pericardium at the same levels of cardiac output, pericardial pressures were derived. In all the range of the VFC the pericardial pressures were positive, and this pressure increase as cardiac output increase. Thus the transmural pressure was never cero, for both right and left ventricles. The observed relation for the R and L filling pressures, derived from a polynomial equation of second order suggest a small although not unimportant effect of the pericardium at normal filling pressures, and a very substantial influence at high levels of cardiac output. The demarcation between small and major effects appears in the upper range of normal filling pressures in this dynamic approach of the pericardial pressures.
Assuntos
Pericárdio/fisiologia , Função Ventricular Esquerda/fisiologia , Função Ventricular Direita/fisiologia , Pressão Ventricular/fisiologia , Algoritmos , Animais , Cães , Feminino , Masculino , Pericárdio/cirurgiaRESUMO
The objective of our study was to validate the diagnostic utility of cardiac troponine T in acute ischemic syndromes, and also in cases of difficult diagnosis. We analyzed its concordance and compare them with conventional enzymatic quantitative methods. We determined sensitivity, specificity, positive and negative predictive values and likelihood ratio. Kappa index was used to know the concordance grade between T troponin and the positive or negative results of the quantitative enzymatic curve. Stochastic significance was valued by Chi square of Mcnemar test. In seventy patients who arrived to the hospital with chest pain who were assigned to five different groups. The sensitivity in quantitative markers was higher than qualitative methods, however the specificity, likelihood ratio was lower. In the total group the concordance analysis between qualitative and quantitative markers was adequate, (kappa index 0.65 p < 0.05). This study suggest that the rapid bedside qualitative test by cardiac Troponin T is a good diagnostic marker compared with conventional quantitative markers to evaluate chest pain in acute ischemic syndromes.
Assuntos
Creatina Quinase/análise , Isquemia Miocárdica/diagnóstico , Miocárdio/metabolismo , Mioglobina/análise , Sistemas Automatizados de Assistência Junto ao Leito , Troponina T/análise , Doença Aguda , Ensaios Enzimáticos Clínicos , Feminino , Humanos , Isoenzimas , Masculino , Pessoa de Meia-Idade , Miocárdio/enzimologiaRESUMO
We evaluated 249 patients (pts) with first acute myocardial infarction: 1. Pts without thrombolysis, n = 119, 2. Pts treated with thrombolysis within 6 hours following MI, n = 80 and 3. Pts treated with thrombolysis between 6-12 hours after MI. Arrhythmic events were evaluated during follow up. All underwent heart rate variability studies and coronary angiogram where anterograde flow (TIMI) and collateral flow (Rentrop scale 0-2 = poor collateral flow and 3 = good collateral flow) were determined. Pts in group 2 and 3 showed a better anterograde and collateral flow than group 1 (p < 0.001). A lower spectral power in the high frequency band and a higher ratio low/high frequency band were observed in group 1 (p < 0.05). Conjunctive consolidation analysis showed more malignant arrhythmias in TIMI 0-2 with poor collateral flow than TIMI 0-2 with good collateral flow (17/138-12.3% vs 0/14-0%). Kaplan Meier analysis was able to demonstrate more cardiac sudden death events in TIMI 0-2 with poor collateral flow than TIMI 0-2 with good collateral flow or TIMI 3 (x2 = 7.22, p = 0.028), independently of thrombolytic treatment.
Assuntos
Circulação Colateral , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/fisiopatologia , Terapia Trombolítica , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Eletrocardiografia Ambulatorial , Eletrofisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicaçõesRESUMO
BACKGROUND: The relationship between myocardial bridging (MB) and ischemic heart disease is still controversial. However, a recent new evidence suggests that this relation is not by chance. PURPOSE: The purpose of our study was to review in a critical manner, the evidence for the relationship between MB and myocardial ischemia and its possible consequences. METHODS: We present 2 cases of our series and review the medical literature from January 1966 to January 1998 published and included in Medline and Current Contents. RESULTS AND CONCLUSIONS: The principal findings after this review were: 1) MB is not a normal variant; 2) The clinical impact of MB depends on its anatomical extension and degree of compressive effect; 3) The MB muscle is not similar to myocytes from other cardiac areas; 4) The environment surrounding coronary artery may be a crucial factor in determining whether the MB influences the induction of heart disorders or not; 5) The overshoot due to compressive effect on coronary artery might determine endothelial injury in the microcirculation post-MB; 6) In some cases, the systolic endothelial injury may contribute to release factors that are able to reduce the coronary reserve, resulting in myocardial ischemia; 7) The possible role of PTCA in this disorder still has to be proven. Surgical treatment should be considered when important myocardial ischemia had been demonstrated, even in those asymptomatic cases.
Assuntos
Circulação Coronária , Anomalias dos Vasos Coronários/fisiopatologia , Endotélio Vascular/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Adulto , Anomalias dos Vasos Coronários/complicações , Anomalias dos Vasos Coronários/cirurgia , Eletrocardiografia , Endotélio Vascular/patologia , Feminino , Humanos , Microcirculação , Isquemia Miocárdica/complicações , Isquemia Miocárdica/cirurgiaRESUMO
BACKGROUND: Analysis of high-frequency QRS complex envelope has been suggested as a method that could detect myocardial ischemia but the characteristics of the turbulence spectral from an spectral-temporal mapping into the QRS complex has not been studied yet. This is a prospective study of phase I for the validation of a new diagnostic test. AIMS: The aims for this study are: 1) To validate a new method for the detection of transient myocardial ischemia by both, high-frequency QRS and spectral turbulence analysis, which we have named "high-fidelity spectrocardiogram" (HFS). 2) To compare the sensitivity, specificity and accuracy of this HFS versus those obtained from nuclear medicine (NM-MIBI) and a conventional exercise ECG test, in a highly selected population. PATIENTS AND METHODS: Twenty-five patients (P) were studied: 10 P (Group B) with risk factors for coronary artery disease, without previous infarct, who had atypical precordial pain and a conventional ECG considered as "normal" by two cardiologists. The group A was formed by 15 P without risk factors or another kind of heart disease. All patients underwent a conventional surface ECG, which had to be normal in order to be considered for this study. Echocardiogram, exercise testing ECG and a NM-MIBI study were also normal. The HFS recording was taken before and after Dipyridamole testing, similar to the conventional method for the NM-MIBI (dipyridamole 0.25 mg/Kg/doses) studies. Our software for the analysis of QRS-frequencies was constructed from a language Turbo C++. The Fourier's transform allowed the construction of 3-dimensional graphics. After the determination of the best wide band for detecting changes in the frequency contained of QRS, the determination coefficients (r2) were obtained and compared before and after the challenge with dipyridamole. These changes were compared between groups (A vs B) later. RESULTS: The r2 changed more than 30% after dipyridamole in those patients in whom myocardial ischemia was demonstrated later by NM-MIBI. The sensitivity (85%) and specificity (90%) of HFS were similar to the nuclear medicine for identifying myocardial ischemia, but higher than a conventional exercise ECG testing (p.001). The main change in HFS was in the frequency-contained QRS in the 130-260 Hz band. The accuracy of our method was increased when an analysis of each orthogonal lead was made. There was a clear tendency of the group B to increase the QRS duration, while the contrary was found in group A, being the QRS the shorter (p.064). The chronological responses were different in those patients with ischemia. CONCLUSION: This study suggests that an episode of myocardial ischemia is able to change in a dramatic manner the frequency-contained within of the QRS complex, in spite of an unchanged ST segment in the conventional exercise ECG. We suggest that the HFS could be a good method for identifying myocardial ischemia. Its advantages could be important, particularly when the conventional exercise ECG is non informative.
Assuntos
Eletrocardiografia/métodos , Isquemia Miocárdica/diagnóstico , Processamento de Sinais Assistido por Computador , Idoso , Dipiridamol , Eletrocardiografia/efeitos dos fármacos , Eletrocardiografia/instrumentação , Eletrocardiografia/estatística & dados numéricos , Análise de Fourier , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Valores de Referência , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Processamento de Sinais Assistido por Computador/instrumentação , VasodilatadoresRESUMO
The most common cause of sudden death is malignant ventricular arrhytHmia. In order to identify the predictive value of the vectospatial evaluation in the surface electrocardiogram during a monomorphic ventricular tachycardia (MVT), and the equilibrium state of AutonomOus Nervous System (ANS), 89 patients of both sexes were studied with mean age of 47 +/- 16.2 years. They were grouped as follows: Group I included 43 patients (P), with a coronary heart disease; Group II (n = 24P) with a noncoronary myocardiopathy and Group III (n = 22P) with unknown origin MVT (Cryptogenic). Relationship between QRS configuration in the frontal plane (QRSf) during MVT episode with transverse plane, cardiac position in the chest X-rays, presence and duration of late potentials (LPs) in their two types of analysis (time domain and spectral mapping by high-resolution electrocardiogram), heart rate variability and ejection fraction by echocardiography were determined in all patients. The QRSf configuration with left bundle-branch block (LBBB) was the most common in group I, the sustained MVT (SMVT) + LBBB was associated with both prevalence and duration of late potentials (p = 0.005), low-rate heart variability and ejection fraction < 40%. SMVT + LBBB was the most common type in group III and if it has shown and inferior axis, an elevated rate of LPs (+) was seen. Situation that oriented to an arrhythmogenic right ventricular dysplasia. Low amplitude signals with short duration in the time domain were seen in group I with LBBB; and with SMVT + RBBB in group II. We suggest that vectospatial evaluation of QRSf during a MVT is a greater importance in the risk stratification for sudden death and it can guide to anatomic origin and the diagnosis-therapeutic approach.