Blood Pressure Response to Exercise Testing
Dec 11, 2009
Although in practise blood pressure (BP) is measured during and in recovery from exercise testing, there are no clearly established figures of an abnormal response. Different methods and population studied explain the different definitions. This conflicting data had provoked an inadequate the conduct to follow. This article appreciation of clinical significance, and revises work carried out relevant to blood pressure response in exercise testing, and based on evidence, proposes a series of values and conducts of diagnostic and prognostic significance.
Introduction
Exercise testing is a cardiovascular stimulation test which is performed on treadmill or bicycle, monitoring the electrocardiogram and blood pressure (BP). It has a relatively low cost and is normally used to estimate prognosis, to determine the functional capacity, to assess the probability and extent of coronary disease and to evaluate the effects of treatment or physical training. There are relatively few studies which provide figures for normal pressure response during exercise for adults and adolescents. These studies take into account the age and sex, which is not normally taken into consideration when evaluating a pressure response during exercise.
The manual determination of the BP is still used routinely in practice. It can sometimes be difficult to define the values of resting blood pressure, especially diastolic blood pressure (DBP), either by auditory problems, to define or recognize the fifth Korotkoff sound, or an auscultatory gap. In practice, even with experience, it often can be even more difficult to define the figures for systolic (SBP) and DBP during exercise testing, especially the latter. For example, sometimes the DBP during effort can not be defined in the fifth Korotkoff sound, because sound is heard almost to 0 mm Hg, the fourth must be used to define DBP. The determination of the BP through automatic equipment, with the right technique, offer many advantages over the manual technique, having verified its utility and clinical validity.
As for what is considered to be an abnormal response of blood pressure during effort, even today, there is no clear agreed consensus. The definitions use different parameters and methods of study are also different. Usually absolute figures are taken, although, clearly, there may not have the same clinical significance in blood pressure at maximal effort of 230 mm Hg in an adult of 25 years as in one of 65. Furthermore, possibly the clinical and prognostic significance is not sufficiently valued, leaving some people at possible risk without adequate monitoring or additional studies.
The abnormal BP responses can develop during the test, in recuperation, and even just before exercise testing, having significant clinical value. The hypertensive response (HR), hypotensive, as in an insufficient BP response form part of the abnormal responses during exercise testing. The BP response during the recuperation, frequently not adequately valued, can also contribute relevant clinical information. It is also important to take into account the safety pressure figures during exercise testing, both those of the contraindications as well as the test termination criteria.
The relevance of the BP study in effort lies in its diagnostic potential, not only for arterial hypertension, but also to reflect other pathologies that may alter hemodynamic, such as hypertrophic cardiomyopathy. It also has a potential prognosis on future hypertension, cardiovascular events, stroke and mortality.
This article summarizes recent evidence of studies on the abnormal response of blood pressure in exercise testing, outlining guideline figures for diagnosis and prognosis purposes, with the aim of improving the interpretation and implementation in daily practice.
Normal Response
The normal response of blood pressure in progressive exercise testing is: Systolic blood pressure (SBP) increases while the diastolic blood pressure (DBP) is maintained or decreases slightly.
The normal response of SBP in progressive tests is approximately 7 to 10 mm Hg by MET, about 25 watts, although there are no standard values. (1, 2, 3, 4)
The tension response at submaximal and maximal effort level, and during recovery is dependent on age, sex and physical condition, which should be taken into account when assessing a response in normal exercise testing (Figure 1 and Table 1). (5, 6, 7).
Age
For older patients, one would expect to observe higher values of SBP and DBP in submaximal and maximal effort, and also in recovery. (6, 8, 9)
Sex
Generally men have a higher maximal value of SBP (SBPmax) and a quicker recovery than women. (8, 10)
Physical Fitness
In trained subjects the response of SBP is less in submaximal effort than in non-trained subjects, reaching greater SBPmax with normal values of 225-240 mm Hg at high level. By increasing physical fitness, SBPmax increases. (4, 8, 11, 12). Thus, the maximal Delta SBP (i.e. The difference between SBPmax and the resting SBP) reaches greater values in athletes .
The maximal pulse rate (SBP-DBP) during exercise, is also higher in athletes than non-athletes, often exceeding 100 mm Hg. (13) Athletes reach a lower DBPmax. (4) In healthy young people, sometimes the DBP cannot be determined because it can be heard to almost zero level. Poor physical condition is associated with higher blood pressure responses at submaximal and maximal effort. (14)
There is usually post-effort hypotension (values below the initial level ) in both normotensive and in hypertensive patients which may last several hours. (1)
Adult and adolescent hypertensive patients, or those with high body mass index, have higher BT responses during physical effort. (7, 15). The SBP response was higher in obese adolescents, indicating a greater reactivity to physical exertion. (16)
Read on...
To see a short video on why you should be using a Power Examination table click