Relación entre infarto de miocardio y ritmo circadiano en pacientes atendidos por un servicio de emergencias prehospitalario / Relation between myocardial infarction and cyrcadian rhythm in patients attended in a prehospital emergency service

Fundamento y objetivo. El objetivo de este estudio es analizar la presencia de ritmo circadiano en la hora de inicio del infarto agudo de miocardio atendido por un sistema de emergencias prehospitalario, y la influencia en dicho ritmo de algunos factores de riesgo cardiovascular modificables y no modificables como posibles moduladores de ese patrón circadiano. Pacientes y método. Análisis retrospectivo de 709 pacientes con diagnóstico clínico confirmado in situ de infarto agudo de miocardio. Se analizan las variables: hora de inicio de los síntomas, edad, sexo, cardiopatía isquémica previa, hipertensión arterial, diabetes mellitus, dislipidemia y tabaquismo. El análisis de ritmo se ha efectuado utilizando un test simple de igualdad de series basado en el análisis cosinor de múltiples sinusoides, eligiendo 3 armónicos (24,12 y 8h) para su ajuste. Resultados. La hora de inicio del infarto muestra ritmo circadiano (p<0,001), con un pico máximo a las 10.39 y un valle a las 4.28, mostrando una curva sinusoidal ajustada de aspecto bimodal, con un pico matinal predominante y otro vespertino de menor amplitud. Todos los subgrupos categorizados por la presencia de las variables analizadas presentaron ritmo circadiano, con una curva sinusoidal similar a la de la población global. Los pacientes fumadores muestran un pico vespertino predominante. Conclusiones. El infarto de miocardio presenta ritmo circadiano. El tabaquismo y la diabetes modifican el patrón de ritmo circadiano habitual del infarto(AU)

Background and objectives. The aim of this study is to analyze the presence of circadian rhythm in the time of onset of symptoms of acute myocardial infarction treated by a prehospital emergency system and the influence of modifiable cardiovascular risk factors and non-modifiable as modulators of that circadian rhythm. Patients and methods. Retrospective analysis of 709 patients clinically diagnosed with acute myocardial infarction on-site in the prehospital setting. The variables were time to onset of symptoms, age, sex, previous ischemic heart disease, hypertension, diabetes mellitus, hyperlipidemia and smoking. We analyzed the rhythm with cosinor multiple sinusoid method, with 3 harmonics (24, 12 and 8h) for the adjustment. Results. The time of onset of pain showed circadian rhythm (P <,001), peaking at 10.39 and a valley at 4.28, showing a sinusoidal curve fitting bimodal aspect with a predominant morning peak and another evening one of lower amplitude. All subgroups categorized by the study variables showed circadian rhythm, with a cosine curve similar to the global infarction. Smokers had a predominantly evening peak. Conclusions. Acute myocardial infarction shows a circadian rhythm. Smoking and diabetes mellitus can modify the standard incidence rate of occurrence of myocardial infarction(AU)

[Relation between myocardial infarction and circadian rhythm in patients attended in a prehospital emergency service]. / Relación entre infarto de miocardio y ritmo circadiano en pacientes atendidos por un servicio de emergencias prehospitalario.

BACKGROUND AND OBJECTIVES: The aim of this study is to analyze the presence of circadian rhythm in the time of onset of symptoms of acute myocardial infarction treated by a prehospital emergency system and the influence of modifiable cardiovascular risk factors and non-modifiable as modulators of that circadian rhythm. PATIENTS AND METHODS: Retrospective analysis of 709 patients clinically diagnosed with acute myocardial infarction on-site in the prehospital setting. The variables were time to onset of symptoms, age, sex, previous ischemic heart disease, hypertension, diabetes mellitus, hyperlipidemia and smoking. We analyzed the rhythm with cosinor multiple sinusoid method, with 3 harmonics (24, 12 and 8h) for the adjustment. RESULTS: The time of onset of pain showed circadian rhythm (P <,001), peaking at 10.39 and a valley at 4.28, showing a sinusoidal curve fitting bimodal aspect with a predominant morning peak and another evening one of lower amplitude. All subgroups categorized by the study variables showed circadian rhythm, with a cosine curve similar to the global infarction. Smokers had a predominantly evening peak. CONCLUSIONS: Acute myocardial infarction shows a circadian rhythm. Smoking and diabetes mellitus can modify the standard incidence rate of occurrence of myocardial infarction.

Characterization of activity epochs in actimetric registries for infantile colic diagnosis: Identification and feature extraction based on wavelets and symbolic dynamics.

The diagnosis and therapy planning of high prevalence pathologies such as infantile colic can be substantially improved by statistical signal processing of activity/rest registries. Assuming that colic episodes are associated to activity episodes, diagnosis aid systems should be based on preprocessing techniques able to separate real activity from rest epochs, and feature extraction methods to identify meaningful indices with diagnostic capabilities. In this paper, we propose a two step diagnosis aid methodology for infantile colic in children below 3 months old. Identification of activity periods is performed by means of a wavelet based activity filter which does not depend on the acquisition device (as so far proposed methods do). In addition, symbolic dynamic analysis is used for extraction of discriminative indices from the activity time series. Results on real data yielded 100% sensitivity and 80% specificity in a study group composed of 46 cases and 10 control subjects.

Decline and loss of birth seasonality in Spain: analysis of 33,421,731 births over 60 years.

BACKGROUND AND AIM: Several seasonal variations have been found in birth rates in different countries at different periods. The characteristics of the rhythmic patterns vary according to geographical location and chronological changes. This study presents data on spanish birth seasonality over six decades. METHODS: A time series composed of 33,421,731 births in Spain in the period 1941-2000 was analysed. The series comes from the National Institute of Statistics and was processed according to the following norms: (1) normalisation of the duration of months and years; (2) clinical analysis of temporal series (isolation of seasonal component); (3) Fourier's spectral analysis; and (4) cosinor analysis (adjustment to the cosine curve of two harmonics). RESULTS: Significant seasonal rhythm was found in the set of births, both for a 12-month period and a 6-month period. The rhythm shows bimodal morphology, with a pronounced birth peak in April and a smaller one in September. These peaks correspond to July and December conceptions, respectively. The major birth peak shifted to March-May between the 1940s and the 1980s. Birth rhythm changed after the 1960s, with a decrease in amplitude and later loss of seasonality in the 1990s. CONCLUSIONS: In Spain, seasonal birth rhythm shows a decline from 1970, and, finally, lack of birth seasonality in 1991-2000. This trend is similar to other European countries, although Spain shows a more intense loss of seasonality.

Melatonin rhythm in children with enuresis.

OBJECTIVE: To study the circadian rhythm of melatonin in children with enuresis. PATIENTS AND METHODS: Twenty-five children, divided into two groups (enuretic patients and controls) were assessed; salivary samples were collected to measure melatonin by radioimmunoassay using commercial kits. Friedman two-way anova and Wilcoxon tests were used to assess the circadian rhythm of melatonin, and anova with between-patient factors and Mann-Whitney tests to compare melatonin values and groups. RESULTS: Both groups had statistically significant differences in melatonin concentration during the 24-h period (both P < 0.001), with a circadian rhythm; the highest values were always at approximately 04.00 hours. There were no significant differences overall in melatonin values between cases and controls, but patients had lower peak values than controls at 04.00 hours, and higher melatonin levels at 24.00 hours, but with no significant differences. CONCLUSION: There was some evidence for minor disturbances in the circadian rhythm of melatonin as a cause of enuresis, but the rhythm was not grossly disrupted.

Ritmo circadiano del síndrome coronario agudo. Réplica / Circadian rythm in acute coronary syndrome. Author´s reply

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[Differential circadian rhythms in myocardial infarction according to its extent by electrocardiogram]. / Diferencias en el ritmo circadiano del infarto de miocardio según su extensión electrocardiográfica.

BACKGROUND AND OBJECTIVE: To determine the existence of circadian rhythm in the time of onset of acute myocardial infarction (AMI) according to their extension type (Q-wave vs. non-Q-wave). PATIENTS AND METHOD: We studied a retrospective cohort of patients from a multicentre study of myocardial infarction (ARIAM study group). We collected information about 54,249 infarctions from the data base of the ARIAM (Analysis of Delay in AMI) Spanish multicentre study. The following variables were analysed: general variables --age, gender, previous ischemic heart disease, outcome at coronary care unit, infarction electrocardiograph type (Q wave or non-Q wave) and location of AMI--, cardiovascular risk factors, and previous drug treatment of the patients. To verify the presence of circadian rhythm we developed a simple test of equality of time series based on the multiple-sinusoid cosinor analysis. Three sinusoids (24-12-8 h periods) were used. RESULTS: The time of pain onset shows circadian rhythm (p < 0.0000), which also is observed in both infarction electrocardiograph characteristics subgroups (Q-wave infarction and non-Q-wave infarction) (p < 0.0000). Q-wave infarction shows sinusoid curve with one maximum morning peak and non-Q-wave shows bimodal curve, with two peaks. Comparison between their curves shows statistical significance (p < 0.0000). CONCLUSIONS: AMI onset follows a circadian rhythm pattern, which is also observed in analysed subgroups. Differences in the circadian rhythm according to the Q/non-Q wave infarction characteristics, could be determined by different physiopathologic mechanism. The cosinor model fit with three components (24, 12 and 8-hour-periods) show good sensitivity to determine circadian rhythm.

Diferencias en el ritmo circadiano del infarto de miocardio según su extensión electrocardiográfica / Differential circadian rhythms in myocardial infarction according to its extent by electrocardiogram

FUNDAMENTO Y OBJETIVO: Determinar la existencia de ritmo circadiano en la hora de inicio del infarto de miocardio (IM) según su extensión electrocardiográfica Q/no Q. PACIENTES Y MÉTODO: Estudio retrospectivo de una cohorte de pacientes del proyecto ARIAM que incluyó 54.249 IM. Se analizan variables generales del infarto (edad, sexo, cardiopatía isquémica previa, extensión del infarto, localización, supervivencia al alta de la unidad de cuidados intensivos), factores de riesgo cardiovascular y tratamientos farmacológicos previos al episodio estudiado. Para verificar la presencia de ritmo circadiano se ha desarrollado un test simple de igualdad de series basado en el análisis cosinor de múltiples sinusoides, utilizando 3 sinusoides de períodos de 24, 12 y 8 h. RESULTADOS: La hora de inicio de los síntomas del infarto mostró ritmo circadiano (p < 0,0000) tanto en el IM Q como en el IM no Q. Los IM Q presentan un patrón con un único máximo de incidencia matinal y los no Q, un patrón bimodal con doble pico de incidencia. La comparación entre dichos patrones muestra diferencias significativas en su ajuste (p < 0,0000). CONCLUSIONES: La hora de inicio del IM sigue un patrón circadiano, que también se observa en los subgrupos analizados. Las diferencias entre los ritmos circadianos según el tipo de IM (Q frente a no Q) podrían explicarse por el distinto mecanismo fisiopatológico de ambos subtipos de infarto. El modelo de análisis de cosinor ajustado con 3 componentes (períodos de 24, 12 y 8 h) muestra buena sensibilidad para la detección de ritmo circadiano (AU)

[Cardiovascular risk factors in the circadian rhythm of acute myocardial infarction]. / Factores de riesgo cardiovascular en el ritmo circadiano del infarto agudo de miocardio.

INTRODUCTION AND OBJECTIVES: The aim of this study was to analyze the influence of modifiable cardiovascular risk factors on the circadian rhythm of acute myocardial infarction. PATIENTS AND METHOD: We analyzed a retrospective cohort of 54,249 patients from a multicenter study of acute myocardial infarction (the Spanish ARIAM study). The variables were time of onset of symptoms, age, sex, previous ischemic heart disease, coronary unit discharge status, previous stroke, familial antecedents of ischemic heart disease, hypertension, diabetes, dyslipidemia, smoking, and reinfarction. To verify the presence of circadian rhythm, we developed a simple test of equality of time series based on cosinor analysis of multiple sinusoid curves. Three sinusoids (24, 12 and 8 hour periods) were used. RESULTS: The time of onset of pain showed a circadian rhythm (P< .01), with a peak at 10:07 am and a trough at 4:46 am. All subgroups categorized according to the presence of the variables analyzed here showed a circadian rhythm, with a sinusoid curve after adjustment. In patients with diabetes or reinfarction or who were smokers, the sinusoid curve was bimodal. CONCLUSIONS: Time of onset of symptoms in patients with acute myocardial infarction follows a circadian rhythm. Diabetes, smoking and reinfarction can modify the standard circadian rhythm of onset of myocardial infarction.