Ambulatory and central haemodynamics during progressive ascent to high-altitude and associated hypoxia

Por: M G Schultz, R E D Climie y J E Sharman.  

High-altitude hypoxia causes major cardiovascular changes, which may result in raised resting brachial blood pressure (BP). However, the effect of high-altitude hypoxia on more sensitive measures of BP control (such as 24?h ambulatory BP and resting central BP) is largely unknown. This study aimed to assess this and compare high-altitude responses to resting brachial BP, as well as determine the haemodynamic correlates of acute mountain sickness (AMS) during a progressive trekking ascent to high-altitude. Measures of oxygen saturation (pulse oximetry), 24?h ambulatory BP, resting brachial and central BP (Pulsecor) were recorded in 10 adults (aged 27±4, 30% male) during a 9-day trek to Mount Everest base camp, Nepal. Data were recorded at sea level (stage 1; <450?m above sea level (ASL)) and at progressive ascension to 3440?m ASL (stage 2), 4350?m ASL (stage 3) and 5164?m ASL .

Monitorización ambulatoria de la presión arterial y actividad física en pacientes hipertensos

Por: L. García-Ortiz,  A. de Cabo-Laso, C. Rodriguez-Martín, J.I. Recio-Rodríguez, A. Garcia Garcia, E. Rodriguez-Sanchez, C. Agudo-Conde y M.A. Gomez-Marcos.     Hipertension y Riesgo Vascular  Vol. 31. Núm. 04. Octubre 2014 – Diciembre 2014.

Analizar la relación entre el patrón circadiano de la presión arterial ambulatoria de 24 h y la actividad física habitual en sujetos hipertensos.

Material y métodos

Estudio transversal en el que se incluyeron 552 pacientes hipertensos del estudio EVIDENT (edad media 61 ± 55 años; 49,5% mujeres). La presión arterial ambulatoria se valoró con un tonómetro radial (dispositivo-B pro) y la actividad física se evaluó con un acelerómetro Actigraph GT3X (counts/minuto) durante 7 días.

Resultados

Los pacientes con patrón circadiano dipper realizaban mayor actividad física habitual que los no dipper. Las medidas de la actividad física (counts/minuto) presentaron correlación negativa con el ratio noche/día de las presiones arteriales sistólica y diastólica (? = -0,227 y ? = -0,205; p < 0,001), respectivamente. Esta asociación se mantuvo en la regresión lineal múltiple después de ajustar por factores de confusión (ß = -0,016; p < 0,001). En la regresión logística, considerando el patrón circadiano como variable dependiente (1: dipper; 0: no dipper), la odds ratio del tercer tertil de counts/minuto respecto del primero fue de 2,80 (IC 95%: 1,73-4,51; p < 0,001) después de ajustar por las variables de confusión.

Conclusiones

La actividad física evaluada con acelerómetro se asoció con un mayor descenso nocturno de la presión arterial y, en consecuencia, un menor ratio noche/día de la presión arterial sistólica y diastólica en sujetos hipertensos.

Resistant hypertension—complex mix of secondary causes and comorbidities

Por: T. Dudenbostel.  Journal of Human Hypertension (2014) 28, 1–2.

Resistant hypertension (RHTN) is an increasingly common clinical problem1, 2 that studies have suggested is almost always heterogeneous in terms of etiology, risk factors and comorbidities. There has been a growing interest in defining epidemiology and pathophysiology in hope of identifying treatment targets.

Cross-sectional assessments of subjects with RHTN compared with subjects without RHTN have consistently found the former to have an increased frequency of cardiovascular complications, including prior myocardial infarction, stroke, congestive heart failure and chronic kidney disease (CKD). A recent 5-year longitudinal assessment of cardiovascular outcomes in a large cohort of subjects with rigorously defined RHTN demonstrated a 50% increase in cardiovascular events in RHTN subjects compared with patients whose blood pressure (BP) had been controlled on less than or equal to3 medications.

Effects of Immediate Blood Pressure Reduction on Death and Major Disability in Patients With Acute Ischemic Stroke

Por: Jiang He, MD, PhD; Yonghong Zhang, MD, PhD; Tan Xu, MD, PhD; Qi Zhao, MD, PhD; Dali Wang, MD; Chung-Shiuan Chen, MS; Weijun Tong, MD; Changjie Liu, MD; Tian Xu, MD; Zhong Ju, MD; Yanbo Peng, MD; et al.
Stroke is the second leading cause of death and the leading cause of serious, long-term disability worldwide.1 Clinical trials have documented that lowering blood pressure reduces the risk of stroke in hypertensive and normotensive patients with a history of stroke or transient ischemic attack. Although the benefit of lowering blood pressure for primary and secondary prevention of stroke has been established, the effect of immediate antihypertensive treatment in patients with acute ischemic stroke and elevated blood pressure is uncertain.  Elevated blood pressure is common during acute ischemic stroke.