Track topics on Twitter Track topics that are important to you
Human baroreflex regulation plays an important role in stabilising blood pressure. Though we have several indices to quantify cardiovagal responses, sympathetic baroreflex gain remains difficult to assess. We investigated how the recently validated pressure recovery time (PRT) and sympathetic baroreflex gain (SBRS) derived from the Valsalva maneuver was influenced by acute blood loss. 26 healthy blood donors were included in the study (age 35±15years; 20 men). SBRS was derived from the blood pressure drop (SAP delta) and pressure recovery time during the Valsalva maneuver. Besides we calculated cardiovagal baroreflex parameters, the Valsalva ratio (VR) and a simplified baroreflex gain (VBRS). We compared these parameters before and after the withdrawal of 350-400ml blood. The baseline systolic blood pressure was the same before and after blood donation (123±17 vs 126±23mm Hg, NS). The minimum systolic pressure (SAP min) during phase III was significantly lower, and the SAP delta significantly greater after blood withdrawal (SAP min 83±24mm Hg vs 69±27mm Hg, p<0.001; SAP delta 41±15mm Hg vs 57±16mm Hg, p<0.001). PRT increased significantly (from 2.0 to 3.6s, p<0.006). SBRS did not change between the study conditions (24±12mm Hg/s vs 22±10mm Hg/s, NS), nor did the VR and the
In conclusion, after the acute loss of approximately 350-400ml blood there was a greater blood pressure drop in phase II and III and a slower blood pressure recovery in phase IV of the Valsalva maneuver that resulted in an unchanged SBRS.
Gottsegen György National Institute of Cardiology, Hungary.
This article was published in the following journal.
Name: Autonomic neuroscience : basic & clinical
Despite the great value of diagnostic bloodwork for identifying disease in animals, the volume of blood required for these analyses limits its use in laboratory mice, particularly when they are clinic...
Although blood pressure measured over the brachial artery is a powerful predictor of cardiovascular morbidity and mortality, recent studies suggest that central blood pressure is more closely associat...
Elevated blood pressure is common in patients with acute ischemic stroke. Thrombolytic therapy is contraindicated in patients with a systolic blood pressure greater than 185 mmHg or diastolic blood pr...
To investigate the influence of arm circumference (AC) on the brachial blood pressure (BP) measured with an adult cuff.
Blood pressure is a potent determinant of cardiovascular risk, but the most appropriate targets for blood-pressure lowering have long been debated. Observational studies with a low risk of confounding...
The manipulation of blood pressure in acute cerebral ischemia has been a matter of debate until now. The investigators are clearly in need of more detailed data on how antihypertensive tre...
The study aimed to evaluate the chronic and acute effects of high-intensity resistance training on blood pressure and its hemodynamic and neural determinators in healthy normotensive older...
The purpose of this study is to determine whether blood pressure control by home blood pressure monitoring exerts beneficial cardioprotective effects rather than by clinic blood pressure m...
Major liver resection is associated with substantial intraoperative blood loss. Blood loss in elective liver surgery is a significant factor of perioperative morbidity and mortality, as we...
Exenatide is a new drug which lowers blood sugar (glucose) levels for people with type 2 diabetes. It has significant advantages over other treatments such as insulin as it causes weight l...
Excess blood loss from uterine bleeding associated with OBSTETRIC LABOR or CHILDBIRTH. It is defined as blood loss greater than 500 ml or of the amount that adversely affects the maternal physiology, such as BLOOD PRESSURE and HEMATOCRIT. Postpartum hemorrhage is divided into two categories, immediate (within first 24 hours after birth) or delayed (after 24 hours postpartum).
Method in which repeated blood pressure readings are made while the patient undergoes normal daily activities. It allows quantitative analysis of the high blood pressure load over time, can help distinguish between types of HYPERTENSION, and can assess the effectiveness of antihypertensive therapy.
A response by the BARORECEPTORS to increased BLOOD PRESSURE. Increased pressure stretches BLOOD VESSELS which activates the baroreceptors in the vessel walls. The net response of the CENTRAL NERVOUS SYSTEM is a reduction of central sympathetic outflow. This reduces blood pressure both by decreasing peripheral VASCULAR RESISTANCE and by lowering CARDIAC OUTPUT. Because the baroreceptors are tonically active, the baroreflex can compensate rapidly for both increases and decreases in blood pressure.
The sudden loss of blood supply to the PITUITARY GLAND, leading to tissue NECROSIS and loss of function (PANHYPOPITUITARISM). The most common cause is hemorrhage or INFARCTION of a PITUITARY ADENOMA. It can also result from acute hemorrhage into SELLA TURCICA due to HEAD TRAUMA; INTRACRANIAL HYPERTENSION; or other acute effects of central nervous system hemorrhage. Clinical signs include severe HEADACHE; HYPOTENSION; bilateral visual disturbances; UNCONSCIOUSNESS; and COMA.
PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...