Toward a Cenozoic history of atmospheric CO2.

The geological record encodes the relationship between climate and atmospheric carbon dioxide (CO2) over long and short timescales, as well as potential drivers of evolutionary transitions. However, reconstructing CO2 beyond direct measurements requires the use of paleoproxies and herein lies the challenge, as proxies differ in their assumptions, degree of understanding, and even reconstructed values. In this study, we critically evaluated, categorized, and integrated available proxies to create a high-fidelity and transparently constructed atmospheric CO2 record spanning the past 66 million years. This newly constructed record provides clearer evidence for higher Earth system sensitivity in the past and for the role of CO2 thresholds in biological and cryosphere evolution.

Cardiomyopathy induced by incessant fascicular ventricular tachycardia / Miocardiopatía inducida por taquicardia ventricular fascicular incesante

A 12-year-old girl with symptoms of fatigue, decreased exercise tolerance and progressive dyspnea (New York Heart Association functional class III) with a possible diagnosis of dilated cardiomyopathy secondary to viral myocarditis. Because of incessant wide QRS tachycardia refractory to antiarrhythmic drugs, she was referred for electrophysiological study. The diagnosis was idiopathic left ventricular tachycardia involving the posterior fascicle of the left bundle branch. After successful treatment with radiofrequency catheter ablation guided by a Purkinje potential radiological and echocardiographic evaluation showed complete reversal of left ventricular function in the first 3 months and no recurrence of arrhythmia during 2 years of follow up.

Niña de 12 años de edad con síntomas por fatiga, disminución de la tolerancia al ejercicio y disnea progresiva (clase funcional III de la New York Heart Association) con un posible diagnóstico de miocardiopatía dilatada secundaria a miocarditis viral. Debido a taquicardia con QRS ancho de comportamiento incesante refractaria a diversos fármacos antiarrítmicos fue referida para estudio electrofisiológico. El diagnóstico final fue taquicardia ventricular izquierda idiopática con participación del fascículo posterior de la rama izquierda. Después del tratamiento exitoso con ablación transcatéter con radiofrecuencia guiado por un potencial de Purkinje la evaluación radiológica y ecocardiográfica demostró reversión completa de la función ventricular izquierda en los primeros 3 meses y sin recurrencia de la arritmia durante 2 años de seguimiento.

Cardiomyopathy induced by incessant fascicular ventricular tachycardia.

A 12-year-old girl with symptoms of fatigue, decreased exercise tolerance and progressive dyspnea (New York Heart Association functional class III) with a possible diagnosis of dilated cardiomyopathy secondary to viral myocarditis. Because of incessant wide QRS tachycardia refractory to antiarrhythmic drugs, she was referred for electrophysiological study. The diagnosis was idiopathic left ventricular tachycardia involving the posterior fascicle of the left bundle branch. After successful treatment with radiofrequency catheter ablation guided by a Purkinje potential radiological and echocardiographic evaluation showed complete reversal of left ventricular function in the first 3 months and no recurrence of arrhythmia during 2 years of follow up.

Cardiomiopatía inducida por taquicardia en niños y adolescentes / Tachycardia-induced cardiomyopathy in children and adolescents

Introducción. La cardiomiopatía dilatada idiopática es la forma más común de cardiomiopatía en niños; sin embargo, ocasionalmente son identificadas causas potencialmente reversibles. Entre estas existe un grupo de pacientes con manifestaciones de insuficiencia cardiaca y taquicardia persistente que representan una forma de cardiomiopatía no familiar adquirida conocida como cardiomiopatía inducida por taquicardia o taquicardiomiopatía, que es reversible con el tratamiento efectivo de la taquicardia. Estos pacientes pueden ser mal diagnosticados y tratados de forma inapropiada. El diagnóstico frecuentemente es tardío, por lo que debe sospecharse en pacientes con insuficiencia cardiaca y taquicardia persistente sin causa aparente. Casos clínicos. Se describen seis casos de pacientes pediátricos de 6 a 16 años de edad (media 12 ± 4 años) que se presentaron con manifestaciones clínicas de insuficiencia cardiaca. Tuvieron seguimiento por una forma de cardiomiopatía dilatada en los que se documentaron diferentes mecanismos de taquiarritmia persistente como la causa. El tratamiento apropiado -mediante ablación con catéter- condujo a la recuperación de la función ventricular. Conclusiones. Es importante el reconocimiento de la cardiomiopatía inducida por taquiarritmia en pediatría. También es necesario un diagnóstico oportuno así como un tratamiento eficaz, ya que la cardiomiopatía inducida por taquicardia es una causa reversible de insuficiencia cardiaca.

Background. Idiopathic dilated cardiomyopathy is the most common form of cardiomyopathy in children; however, potentially reversible causes may occasionally be identified. Among these a group of patients with symptoms of congestive heart failure and persistent tachycardia representing a form of nonfamilial acquired cardiomyopathy known as tachycardia-induced cardiomyopathy or tachycardiomyopathy. This is a reversible condition with effective treatment of tachycardia. These patients may be misdiagnosed, potentially leading to inappropriate treatment. Diagnosis is often late and always should be suspected in patients with congestive heart failure and unexplained persistent tachycardia. Case reports. We describe six pediatric patients (mean age 12 ±4 years old, range 6-16 years). Patients presented with clinical manifestations of heart failure followed by dilated cardiomyopathy. Different mechanisms of persistent tachycardia were documented as the cause and total recovery was achieved of ventricular function after successful treatment of tachycardia by catheter ablation. Conclusions. The recognition of tachyarrhythmia-induced cardiomyopathy in pediatric patients is important. Opportune diagnosis and effective treatment are necessary because tachycardia-induced cardiomyopathy is a reversible cause of heart failure.

La electrofisiología del Wolff-Parkinson-White en el paciente asintomático con actividad o riesgo profesional alto / The electrophysiology of Wolff-Parkinson-White in the asymptomatic patient with activity or with high professional risk

Objetivo: Describir las características electrofisiológicas en individuos con Wolff-Parkinson-White asintomático con actividad deportiva o alta responsabilidad profesional. Métodos: Se evaluaron 19 individuos, edad media 33 ± 13 años (grupo A). Las características electrofisiológicas fueron comparadas con un grupo control similar con WPW sintomático (grupo B). Resultados: En estado basal el periodo refractario anterógrado y la conducción anterógrada 1:1 sobre el fascículo accesorio fueron más largos en el grupo A (300 ± 48 ms vs 262 ± 32 ms, p < 0.05) y (355 ± 108 ms vs 307 ± 86 ms, p < 0.05), respectivamente. Ningún individuo del grupo A tuvo un periodo refractario anterógrado < 250 ms; y 58% no tuvieron conducción retrógrada sobre el fascículo accesorio vs 4% del grupo B (p< 0.001). La inducción de taquicardia fue significativamente menor (5.2%) en el grupo A vs grupo B (95%) (p < 0.001). Se indujo fibrilación auricular (FA) sólo en uno del grupo A vs en 32% grupo B (p< 0.001). Conclusión: Se confirman las características electrofisiológicas benignas en individuos asintomáticos comparados con sintomáticos. La deficiente conducción anterógrada junto con ausencia de conducción retrógrada explica la baja frecuencia de taquiarritmias y no apoyaría la investigación rutinaria en toda la población asintomática, pero debido a las posibles consecuencias, se mantiene la indicación sistemática con fines de ablación preventiva en el subgrupo de individuos asintomáticos con actividad deportiva o alta responsabilidad profesional.

Objective: Describe the electrophysiological characteristics in subjects with asymptomatic Wolff-Parkinson-White with sports activities or high professional responsibility. Methods: Nineteen subjects, mean age 33 ± 13 years (group A). The electrophysiological characteristics were compared with a matched group with symptomatic WPW (group B). Results: At baseline the anterograde refractory period and the anterograde conduction 1:1 over the accessory pathway were longer in group A (300 ± 48 ms vs 262 ± 32 ms, p <0.05 and 355 ± 108 ms vs 307 ± 86 ms, p <0.05), respectively. None of group A had a anterograde refractory period < 250 ms and 58% showed absence of retrograde conduction over the accessory pathway vs 4% of group B (p < 0.001). Induction of tachycardia was significantly less in group A (5%) than in group B (92%) (p < 0.001). Atrial fibrillation was induced in only one of group A vs 32% of group B (p< 0.001). Conclusion: We confirm the benign electrophysiological characteristics in asymptomatic compared to symptomatic subjects. Poor anterograde conduction along with absence of retrograde conduction explains the low frequency of tachyarrhythmias and would not support the routine investigation of all asymptomatic subjects. But, due to possible consequences, remains the systematic indication for preventive ablation in the subgroup of asymptomatic subjects with sporting activities or high professional responsibility.

[The electrophysiology of Wolff-Parkinson-White in the asymptomatic patient with activity or with high professional risk]. / La electrofisiología del Wolff-Parkinson-White en el paciente asintomático con actividad o riesgo profesional alto.

OBJECTIVE: Describe the electrophysiological characteristics in subjects with asymptomatic Wolff-Parkinson-White with sports activities or high professional responsibility. METHODS: Nineteen subjects, mean age 33 ± 13 years (group A). The electrophysiological characteristics were compared with a matched group with symptomatic WPW (group B). RESULTS: At baseline the anterograde refractory period and the anterograde conduction 1:1 over the accessory pathway were longer in group A (300 ± 48 ms vs 262 ± 32 ms, p < 0.05 and 355 ± 108 ms vs 307 ± 86 ms, p < 0.05), respectively. None of group A had a anterograde refractory period< 250 ms and 58% showed absence of retrograde conduction over the accessory pathway vs 4% of group B (p < 0.001). Induction of tachycardia was significantly less in group A (5%) than in group B (92%) (p < 0.001). Atrial fibrillation was induced in only one of group A vs 32% of group B (p < 0.001). CONCLUSION: We confirm the benign electrophysiological characteristics in asymptomatic compared to symptomatic subjects. Poor anterograde conduction along with absence of retrograde conduction explains the low frequency of tachyarrhythmias and would not support the routine investigation of all asymptomatic subjects. But, due to possible consequences, remains the systematic indication for preventive ablation in the subgroup of asymptomatic subjects with sporting activities or high professional responsibility.

The Smoking Consequences Questionnaire: Factor structure and predictive validity among Spanish-speaking Latino smokers in the United States.

INTRODUCTION: Much of the existing research on smoking outcome expectancies has been guided by the Smoking Consequences Questionnaire (SCQ ). Although the original version of the SCQ has been modified over time for use in different populations, none of the existing versions have been evaluated for use among Spanish-speaking Latino smokers in the United States. METHODS: The present study evaluated the factor structure and predictive validity of the 3 previously validated versions of the SCQ--the original, the SCQ-Adult, and the SCQ-Spanish, which was developed with Spanish-speaking smokers in Spain--among Spanish-speaking Latino smokers in Texas. RESULTS: The SCQ-Spanish represented the least complex solution. Each of the SCQ-Spanish scales had good internal consistency, and the predictive validity of the SCQ-Spanish was partially supported. Nearly all the SCQ-Spanish scales predicted withdrawal severity even after controlling for demographics and dependence. Boredom Reduction predicted smoking relapse across the 5- and 12-week follow-up assessments in a multivariate model that also controlled for demographics and dependence. DISCUSSION: Our results support use of the SCQ-Spanish with Spanish-speaking Latino smokers in the United States.