Clinical applications of exercise stress echocardiography in the treadmill with upright evaluation during and after exercise
Cardiovascular Ultrasound
Clinical applications of exercise stress echocardiography in the treadmill with upright evaluation during and after exercise
Carlos Cotrim 0
Isabel Joo 0
Paula Fazendas 0
Ana R Almeida 0
Lus Lopes 0
Bruno Stuart 0
Ins Cruz 0
Daniel Caldeira 0
Maria Jos Loureiro 0
Gonalo Morgado 0
Hlder Pereira 0
0 Cardiology Department, Garcia de Orta Hospital, Avenida Torrado da Silva , 2805-267 Almada , Portugal
Exercise stress echocardiography is the most frequently used stress test in our laboratory. Exercise echocardiography is used mainly in the study of patients with coronary artery disease. However, the technique is increasingly being used to study other diseases. In our centre, we use an original methodology, published by us in 2000, in which we evaluate heart function during exercise in the treadmill. After the exercise, patients are maintained in orthostatic position when appropriate or lying down in left lateral decubitus for further evaluation. Since this method seems to increase the quality and the quantity of information obtained in so many clinical arenas, we now present a detailed review of this methodology and its applications.
Exercise stress echocardiography; Treadmill; Orthostatic evaluation; Pulmonary hypertension; Mitral stenosis; Intra-ventricular gradients; Athletes; Cardiac X syndrome; Hypertrophic cardiomyopathy; Aortic stenosis
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Introduction
The high prevalence of coronary artery disease has led to
the development of reliable and accessible non-invasive
diagnostic techniques. Among these, stress
echocardiography has been accepted as a valuable method in the
detection of myocardial ischemia [1-8] outweighing the
limitations imposed by the widely used treadmill stress
test. In our center, stress echocardiography is preferentially
performed using a treadmill exercise protocol.
Pharmacological stress echocardiography is only used to evaluate
myocardial viability, or when patients cannot exercise
adequately.
Methodology of exercise stress echocardiography
Exercise test in treadmill
Firstly, patients are questioned about their symptoms,
past cardiovascular medical history and risk factors for
coronary artery disease. After an explanation and
preparation for the procedure by a cardiopulmonary
technician, a 12-lead electrocardiogram is obtained. Bruce
protocol is usually performed. In the assessment of
noncoronary artery disease, a modified Bruce protocol is
applied for easier evaluation of Doppler parameters rather
than the classical Bruce protocol, in some clinical
scenarios.
Criteria for test interruption are: fatigue, angina with
increasing intensity, dizziness, ST-segment depression
greater than 3 mm, complex ventricular arrhythmias,
systolic blood pressure greater than 240 mmHg or
diastolic blood pressure greater than 130 mmHg or a blood
pressure drop greater than 20 mmHg. The test is
considered to be positive for myocardial ischemia when
STsegment depression occurs, with a horizontal or down
sloping displacement greater than 1 mm measured
0.08 seconds after the J point. The ECG exercise
treadmill test is considered inconclusive when there are
baseline ST-T changes (left bundle branch block, digitalis
effect, left ventricular hypertrophy) or when the patient
does not reach 85% of the theoretical maximum
ageadjusted heart rate. The exam is negative for myocardial
ischemia when the patients heart rate exceeds 85% of
the theoretical maximum age-adjusted heart rate
without the previously mentioned changes.
Exercise stress echocardiography
Exercise stress echocardiography is performed in our
center since 1996. This method allows the evaluation of
cardiac function, rather than electrical activity, during
exercise. Peteiro et al. have firstly published imaging
acquisition during exercise in 1999 [6] and one year after
we published a detailful methodology article[7] and most
recently other centers have also described it [8,9].
Basically, before starting the exercise test, a baseline
echocardiogram is performed in the left lateral decubitus
position (Figure 1) for initial assessment, with 2D and
M-mode image acquisition in at least four planes:
parasternal long axis, parasternal short axis, apical four-chamber
and apical two-chamber; with Doppler parameters being
evaluated and stored according to the patients disease.
These were re-evaluated if possible during the first
minute before starting the exercise stress treadmill test in
the standing position.
In our center, 2D echocardiography is also performed
in the standing position throughout the exercise test
(Figure 2, see Additional file 1 and 2) with image
acquisition at exercise peak.
After stopping the exercise test the patient is quickly
placed in the left lateral decubitus position and images
are again acquired in the previously referred planes
(Additional file 3). In some circumstances, for example for
the detection and evaluation of intra-ventricular gradients
in hypertrophic cardiomyopathy, the patient is kept
(...truncated)