Exercise testing is a noninvasive tool to evaluate the cardiovascular
system's response to exercise.
Exercise is the body's most common physiologic stress, and it
places major demands on the cardiopulmonary system.
Thus, exercise can be considered the most practical test of cardiac
perfusion and function.
Body increase its resting metabolic rate up to 20 times, cardiac
output 6 times
Total body or ventilatory oxygen uptake (volume oxygen
consumption [VO2]) is the amount of oxygen that is extracted from
inspired air as the body performs work.
The determinants of VO2 are cardiac output and the peripheral
arteriovenous oxygen difference. Maximal arteriovenous difference is
physiologically limited to roughly 15 to 17 mL/dL.
Thus maximal arteriovenous difference behaves more or less as a
constant, making maximal oxygen uptake an indirect estimate of
maximal cardiac output.
Myocardial oxygen uptake is the amount of oxygen consumed by the
Myocardial oxygen demand is related to heart rate, blood pressure, left
ventricular contractility (myocardial shortening per beat), and left
ventricular wall stress(related to left ventricular pressure, wall thickness,
and cavity size).
It has been shown that myocardial oxygen uptake can be reasonably
estimated by the product of heart rate and systolic blood pressure (double
Higher the double product achieved the better is myocardial perfusion
Exercise testing fundamentally involves the measurement of work.
The MET, or metabolic equivalent, is a term commonly used
clinically to express the oxygen requirement of the work rate during
an exercise test on a treadmill or cycle ergometer.
One MET is equated with the resting metabolic rate (approximately
3.5 mL of O2/kg/min),
The exercise protocol should be progressive with even increments
in speed and grade whenever possible.
Smaller, even, and more frequent work increments are preferable to
larger, uneven, and less frequent increases, because the former
yield a more accurate estimation of exercise capacity
In general, 6 to 12 minutes of continuous progressive exercise
during which the myocardial oxygen demand is elevated to the
patient's maximal level is optimal for diagnostic and prognostic
The protocol should include a suitable recovery or cool-down period
Arm crank ergometry protocols involve arm cranking at incremental
workloads of 10 to 20W for 2- or 3-minute stages.
A bicycle ergometer with the axle placed at the level of the
shoulders is used, and the subject sits or stands and cycles the
peddles so that the arms are fully extended alternately.
The most common frequency is 50rpm. In normal individuals,
maximal Vo2 for arm cycling approximates 50 to 70 percent of the
same measures as leg cycling.
Peak Vo2 and peak heart rate are approximately 70 percent of the
measures during leg testing
Bicycle protocols involve incremental workloads calibrated in watts
(W) or kilopond-meters per minute (kpm).
One watt is equivalent to approximately 6kpm.
Most protocols start with a power output of 10 or 25W/min
(150kpm), usually followed by increases of 25W every 2 or 3
minutes until endpoints are reached.
Work rate is increased by a uniform amount each minute, ranging
from 5- to 30-W increments
The bicycle ergometer is associated with a lower maximal Vo2 and
anaerobic threshold than the treadmill; maximal heart rate, and
maximal lactate values are often similar
Bruce protocol is popular, and a large diagnostic and prognostic
data base has been published
The Bruce multistage maximal treadmill protocol has 3-minute
periods to allow achievement of a steady state before workload is
A limitation of the Bruce protocol is the relatively large
increase in Vo2 between stages and the additional
energy cost of running as compared with walking at
stages in excess of Bruce's stage III
Starts at a lower workload than the standard test.
Typically used for elderly or sedentary patients.
The fist two stages of the Modified Bruce Test are performed at a
1.7 mph and 0% grade and 1.7 mph and 5% grade.
The third stage corresponds to the first stage of the Standard Bruce
The Naughton and Weber protocols use 1- to 2-
minute stages with 1-MET increments between stages; these
protocols may be more suitable for patients with limited exercise
tolerance, such as patients with compensated congestive heart
The Asymptomatic Cardiac Ischemia Pilot (ACIP) trial use 2-minute
stages, with 1.5-MET increments between stages after two 1min
warm-up stages with 1-MET increments.
Developed to test patients with established CAD .
Result in a linear increase in heart rate and, distributing the time to
occurrence of ST-segment depression over a wider range of heart
rate and exercise time than protocols with more abrupt increments
in workload between stages.
The mACIP protocol produces a similar aerobic demand
as the standard ACIP protocol for each minute of
Well suited for short or older individuals who cannot
keep up with a walking speed of 3 mph.
This protocol is good for a wider range of fitness levels depending
on starting grade.
Allows for gradual increase in grade and speed and may be started
at 0%, 5%, 10%, grade depending on fitness level.
Computer driven protocol that continuously increase workload until
max exertion is reached.
Steady state may not be reached at any given work load.
Computer driven protocol that continuously
increase workload until max exertion is reached.
Steady state may not be reached at any given
BRUCE Normally used large↑Vo2 bet
NAUGHTON&WEBER Limited ex tolerance-
1-2 min stages1 MET
ACIP Established CAD 2 min stages> linear
↑ in HR & Vo2
MOD-ACIP elderly individuals
A 6-minute walk test or a long-distance corridor walk test can be
used to provide an estimate of functional capacity in patients who
cannot perform bicycle or treadmill exercise, such as elderly
patients or those with heart failure, claudication, or orthopedic
During a 6-minute walk test, patients are instructed to walk down a
100-foot corridor at their own pace, attempting to cover as much
ground as possible in 6 minutes.
At the end of the 6-minute interval, the total distance walked is
determined and the symptoms experienced by the patient are
♥Class I (Definitely appropriate) –
♥ Adult males or females (including RBBB or < 1mm resting ST
depression) with an intermediate pre-test probability of coronary
artery disease based on gender, age and symptoms (specific
exceptions are noted under Class II and III below).
♥Class IIa (Probably appropriate) –
♥ Patients with vasospastic angina.
Class IIb (maybe appropriate)
◦ Patients with a high pretest probability of CAD by age,
symptoms, and gender.
◦ Patients with a low pretest probability of CAD by age,
symptoms, and gender.
◦ Patients with less than 1 mm of baseline ST depression and
◦ Patients with electrocardiographic criteria for left ventricular
hypertrophy (LVH) and less than 1 mm of baseline ST
♥Class III (Not appropriate)
♥1. To use the ST segment response in the diagnosis of coronary1. To use the ST segment response in the diagnosis of coronary
artery disease in patients who demonstrate the following baselineartery disease in patients who demonstrate the following baseline
ECG abnormalities:ECG abnormalities:
♥pre-excitation (WPW) syndrome;pre-excitation (WPW) syndrome;
♥electronically paced ventricular rhythm;electronically paced ventricular rhythm;
♥more than one millimeter of resting ST depression;more than one millimeter of resting ST depression;
♥2. To use the ST segment response in the2. To use the ST segment response in the
diagnosis of coronary artery disease indiagnosis of coronary artery disease in MIMI
Patients should be instructed not to eat, drink caffeinated
beverages, or smoke for 3 hours before testing and to wear
comfortable shoes and loose-fitting clothes.
Unusual physical exertion should be avoided before testing.
A brief history and physical examination should be performed, and
patients should be advised about the risks and benefits of the
A written informed consent form is usually required.
A standard 12-lead ECG is usually obtained.
The ECG should be obtained and blood pressure recorded in both
positions, and patients should be instructed on how to perform the
Adequate skin preparation is essential for high-quality recordings,
and the superficial layer of skin needs to be removed to augment
The areas of electrode application are rubbed with an alcohol-
saturated pad to remove oil and rubbed with free sandpaper or a
rough material to reduce skin resistance.
Silver chloride electrodes with a fluid column to avoid direct metal-
to-skin contact produce high-quality tracings; these electrodes have
the lowest offset voltage
Room temperature should be between 64° and 72°F (18° and 22°C)
and humidity less than 60 percent.
The heart rate, blood pressure, and ECG should be recorded at the
end of each stage of exercise, immediately before and immediately
after stopping exercise, at the onset of an ischemic response.
Hyperventilation should be avoided before testing. Subjects with
and without disease can exhibit ST-segment changes with
If maximal sensitivity is to be achieved with an exercise test,
patients should be supine as soon as possible during the
postexercise period (maximal wall stress)
A cool-down walk can be helpful in performing tests on patients with
an established diagnosis undergoing testing for other than
diagnostic reasons – in testing athletes or patients with congestive
heart failure (CHF), valvular heart disease, or a recent (MI).
A cool-down walk after the test can delay or eliminate the
appearance of ST-segment depression.
Monitoring should continue for at least 5 minutes after exercise or
until changes stabilize.
Mason –Likar modification
Extremity electrodes moved to the torso to reduce motion artifact
• Arm electrodes- lateral aspects of infraclavicular fossae
• Leg electrodes-above the anterior iliac crest and below the rib cage
It results in
• Right axis shift
• Increased voltage in inferior leads
• May produce loss of inferior Q waves and development of new Q waves in
Thus, the body torso limb lead positions
cannot be used to interpret a diagnostic rest
Age Gender Typical/Definite
30-39 Males Intermediate Intermediate low (<10%) Very low (<5%)
30-39 Females Intermediate Very Low (<5%) Very low Very low
40-49 Males High (>90%) Intermediate Intermediate low
40-49 Females Intermediate Low Very low Very low
50-59 Males High (>90%) Intermediate Intermediate Low
50-59 Females Intermediate Intermediate Low Very low
60-69 Males High Intermediate Intermediate Low
60-69 Females High Intermediate Intermediate Low
High = >90% Intermediate = 10-90% Low = <10%
Very Low = <5%
ST Segment Displacement
In normal persons, the PR, QRS, and QT intervals shorten as heart
rate increases. P amplitude increases, and the PR segment
becomes progressively more downsloping in the inferior leads.
J point, or junctional, depression is a normal finding during exercise.
In patients with myocardial ischemia, however, the ST segment
usually becomes more horizontal (flattens) as the severity of the
ischemic response worsens.
With progressive exercise, the depth of ST segment depression
may increase, involving more ECG leads, and the patient may
In the immediate postrecovery phase, the ST segment
displacement may persist, with downsloping ST segments and T
wave inversion, gradually returning to baseline after 5 to 10
In about 10 percent of patients, the ischemic response may appear
only in the recovery phase.
Patients should not leave the exercise laboratory area until the
postexercise ECG has returned to baseline
Measurement of ST Segment Displacement
For purposes of interpretation, the PQ junction is usually chosen as
the isoelectric point.
The development of 0.10 mV (1 mm) or more of J point depression
measured from the PQ junction, with a relatively flat ST segment
slope (e.g., less than 0.7 to 1 mV/sec), depressed 0.10 mV or more
80 milliseconds after the J point (ST 80) in three consecutive beats,
with a stable baseline, is considered to be an abnormal response.
the ST 60 measurement should be used at heart rates higher than
The ST segment at rest may occasionally be depressed. When this
occurs, the J point and ST 60 or ST 80 measurements should be
depressed an additional 0.10 mV or more to be considered
In patients with early repolarization and resting ST segment
elevation, return to the PQ junction is normal.
Therefore, the magnitude of exercise-induced ST segment
depression in a patient with early repolarization should be
determined from the PQ junction and not from the elevated position
of the J point before exercise.
Exercise-induced ST segment depression does not localize the site
of myocardial ischemia, nor does it indicate which coronary artery is
Exercise-induced ST segment elevation is relatively specific for the
territory of myocardial ischemia and the coronary artery involved
In patients with more than one millimeter of resting ST-
ST-segment changes isolated to the inferior leads are
more likely to be false-positive responses unless
profound (i.e., more than 1 mm )
lead II has been shown to have a high false-positive rate.
Exercise-induced ST-segment depression in inferior limb leads is a
poor marker for CAD.
In patients without prior myocardial infarction and normal resting
ECG, ST-depression in precordial lead V5 along with V4 and V6 are
reliable markers for CAD,
UPSLOPING ST SEGMENTS.
J point depression is a normal finding during maximal exercise, and
a rapid upsloping ST segment (more than 1 mV/sec) depressed
less than 0.15 mV (1.5 mm) after the J point should be considered
to be normal.
Slow upsloping ST segment may be the only finding in patients with
In patient subsets with a high CAD prevalence, a slow upsloping ST
segment depressed 0.15 mV or more at 80 ms after the J point
should be considered abnormal.
The importance of this finding in asymptomatic individuals or those
with a low CAD prevalence is less certain.
ST depression at rest becoming normal
Does not indicate CAD
Common in females
ST SEGMENT ELEVATION.
The development of 0.10 mV (1 mm) or more of J point elevation,
persistently elevated higher than 0.10 mV at 60 milliseconds after
the J point in three consecutive beats with a stable baseline, is
considered an abnormal response.
Without pathologic Q waves, exercise-induced ST elevation usually
indicates either significant proximal coronary stenosis or epicardial
In contrast, when pathologic Q waves are present, ST-segment
elevation is usually indicative of a left ventricular aneurysm or
significant wall motion changes.
T WAVE CHANGES.
In patient populations with a low CAD prevalence,
pseudonormalization of T waves is a nondiagnostic
In rare cases, this finding may be a marker for
myocardial ischemia in a patient with documented CAD
When the R wave amplitude meets voltage criteria for left
ventricular hypertrophy, the ST segment response cannot be used
reliably to diagnose CAD, even in the absence of a strain pattern.
Loss of R wave amplitude, commonly seen after MI, reduces the
sensitivity of the ST segment response in that lead to diagnose
U wave inversion can occasionally be seen in the precordial leads
at heart rates of 120 beats/min. Although this finding is relatively
specific for CAD, it is relatively insensitive.
ST/HEART RATE SLOPE MEASUREMENTS
Calculation of the maximal ST/heart rate slope in mV/beats/min is
performed by linear regression analysis relating the measured
amount of ST segment depression in individual leads to the heart
rate at the end of each stage of exercise, starting at the end of
An ST/heart rate slope of 2.4 mV/beats/min is considered abnormal,
and values that exceed 6 mV/beats/min are suggestive evidence of
The use of this measurement requires modification of the exercise
protocol so that increments in heart rate are gradual, as in the
Cornell protocol, as opposed to more abrupt increases in heart rate
between stages, as in the Bruce or Ellestad protocols.
A modification of the ST segment/heart rate slope method is the ST
segment/heart rate index calculation, which represents the average
change of ST segment depression with heart rate throughout the
course of the exercise test.
The ST/heart rate index measurements are less than the ST/heart
rate slope measurements, and an ST/heart rate index of 1.6 is
defined as abnormal.
Exercise Induced Arrhythmias
NSVT is uncommon during routine clinical treadmill testing and is
In patients with a history of syncope, sudden death, physical
examination with a large heart, murmurs, ECG showing prolonged
QT, preexcitation, Q waves, and heart failure (HF), then exercise-
testing–induced ventricular arrhythmias are more worrisome.
When healthy individuals exhibit premature ventricular contractions
(PVCs) during testing, there is no need for immediate concern.
Exercise-testing–induced supraventricular arrhythmias are relatively
rare and appear to be benign except for their association with the
development of AF in the future
The normal exercise response is to increase systolic blood pressure
progressively with increasing workloads to a peak response ranging
from 160 to 200 mmHg, with the higher range of the scale in older
patients with less compliant vascular systems.
In normal persons, the diastolic blood pressure does not usually
Failure to increase systolic blood pressure beyond 120 mmHg,
A sustained decrease greater than 10 mmHg repeatable within 15
or a fall in systolic blood pressure below standing resting values
during progressive exercise,
is abnormal and reflects inadequate elevation of cardiac output
because of left ventricular systolic pump dysfunction or an
excessive reduction in systemic vascular resistance
Defined as >210 mmhg in men and >190 mmhg in
Indicative of future development of HTN or
adverse cardiac events.
This variable is one of the most important prognostic measurements
obtained from an exercise test
In patients with known or suspected CAD, a limited exercise
capacity is associated with an increased risk of cardiac events and,
in general, the more severe the limitation, the worse the CAD extent
In estimating functional capacity, the amount of work performed (or
exercise stage achieved) expressed in METs, not the number of
minutes of exercise, should be the parameter measured
The best methods for estimating predicted METs
are the following simple regression equations:
Men: Predicted METs = 18 −(0.15 × Age)
Women: Predicted METs = 14.7 −(0.13 × Age)
A submaximal study is assigned when the peak heart rate achieved
is below the age-predicted maximum heart rate.
An inadequate study is defined by failure to achieve a predefined
goal, such as 85% of the age-predicted maximum heart rate.
The most familiar equation, which was developed principally in middle-
aged men, is
HRmax = 220 − Age
Although easy to apply and calculate, there is considerable variability
with this equation, especially in patients with CAD who are taking beta
blockers. Newer equations have been proposed to replace the 220 −
age rule to generate the age-predicted maximum heart rate:
Men: HRmax = 208 −(0.7 × Age)
Women: HRmax = 206 −(0.88 × Age)
CAD with beta blockers: HRmax = 164 −(0.7 × Age)
The sinus rate increases progressively with exercise.
In some patients who may be anxious about the exercise test, there
may be an initial overreaction of heart rate and systolic blood
pressure at the beginning of exercise, with stabilization after
approximately 30 to 60 seconds.
An inappropriate increase in heart rate at low exercise workloads
may occur in patients who are in atrial fibrillation, physically
deconditioned, hypovolemic, or anemic, or who have marginal left
ventricular function; this increase may persist for several minutes in
the recovery phase
When the heart rate fails to increase appropriately with exercise, it is
associated with an adverse prognosis.
Chronotropic incompetence is determined by decreased heart rate
sensitivity to the normal increase in sympathetic tone during exercise
and is defined as inability to increase heart rate to at least 85 percent
of age-predicted maximum or as an abnormal heart rate reserve.
It reflects an inability to use up all the heart rate reserve.
This finding may indicate autonomic dysfunction, sinus node
disease, drug therapy such as beta blockers, or a myocardial
When the chronotropic index is 80 percent or less, long-term
mortality is increased.
Chronotropic incompetence should not be used to estimate
prognosis in patients on beta blocker therapy.
% of HR reserve used =
HR peak – HR rest / 220 – age – HRrest
Abnormal heart rate recovery (HRR) refers to a relatively slow
deceleration of heart rate following exercise cessation.
This type of response reflects decreased vagal tone and is
associated with increased mortality.
HRR = HR peak – HR 1 min later.
When the postexercise phase includes an upright cool-down, a
value 12 beats/min or less is abnormal.
For patients undergoing stress echocardiography or otherwise
assuming a supine position immediately after exercise, a value 18
beats/min or less is abnormal.
When HRR is measured 2 minutes into recovery, a value 22
beats/min or less is abnormal
The prognostic value of abnormal HRR is independent of the
exercise level attained, beta blocker usage, severity of coronary
disease, left ventricular function, chronotropic incompetence, Duke
treadmill score, and presence of exercise-induced angina or
ischemic electrocardiographic abnormalities.
The heart rate–systolic blood pressure product, an indirect measure
of myocardial oxygen demand, increases progressively with
exercise, and the peak rate-pressure product can be used to
characterize cardiovascular performance.
Most normal individuals develop a peak rate pressure product of 20
to 35 mmHg×beats/min×10-3.
In many patients with significant ischemic heart disease, rate-
pressure products exceeding 25 mmHg× beats/min×10-3 are
However, the cut point of 25 mmHg× beats/min×10-3 is not a useful
Exercise-induced chest discomfort usually occurs after the onset of
ischemic ST segment abnormalities and may be associated with
In some patients, however, chest discomfort may be the only signal
that obstructive CAD is present.
In patients with chronic stable angina, exercise-induced chest
discomfort occurs less frequently than ischemic ST segment
The new development of an S3, holosystolic apical murmur, or
basilar rates in the early recovery phase of exercise enhances the
diagnostic accuracy of the test.
Mark and colleagues
Exercise time – ( 5 x ST deviation ) – ( 4 TM angina index )
Score of -11 or less, 5-year survival rate of 72 percent, as
compared with a 97 percent survival rate among patients at low risk,
with a TM score of +5 or higher.
The strongest predictor of prognosis derived from the exercise test
is exercise capacity.
The weakest predictor is ST-segment depression.
All other variables, such as the heart rate achieved, HRR, blood
pressure response, ventricular arrhythmias, and exercise-induced
angina, fall between these two extremes.
1.Sex-Specific Scores- Separate scores for men and
women incorporate three standard exercise test variables (ST-
segment depression, peak heart rate, exercise angina score) and
several other clinical variables
Cleveland Clinic Score.
This score was initially reported in 2007.
It incorporates most of the important prognostic exercise test
variables, as well as other important clinical variables.
It is more difficult to apply in routine clinical settings.
useful to determine
(1) risk stratification and assessment of prognosis,
(2) functional capacity for activity prescription after hospital discharge,
(3) assessment of adequacy of medical therapy and need to use
supplemental diagnostic or treatment options.
A low-level exercise test (achievement of 5 to 6 METs, or 70 to 80
percent of age-predicted maximum) can be performed before
The ability to complete 5 to 6 METs or 70 to 80 percent of age-
predicted maximum in the absence of an abnormal ECG or blood
pressure is associated with a 1-year mortality rate of 1 to 2 percent
exercise testing carried class I indications before hospital discharge
(submaximal 4 to 7 days), 14 to 21 days after discharge (symptom
limited if not performed before discharge), and 3 to 6 weeks after
class IIa indication as part of an exercise prescription before cardiac
rehabilitation for patients who underwent coronary
RISK STRATIFICATION IN THE EMERGENCY
Exercise testing in the emergency department should
not be performed when
(1) new or evolving ECG abnormalities are noted on the rest tracing,
(2) the levels of cardiac enzymes are abnormal,
(3) the patient cannot adequately perform exercise,
(4) the patient reports worsening or persistent chest pain symptoms,
(5) clinical risk profiling indicates that imminent coronary angiography
Several series of clinically low-risk subjects reported 6-
month cardiac event rates lower than 1 percent with a
normal exercise test result
PREOPERATIVE RISK STRATIFICATION
BEFORE NONCARDIAC SURGERY
Exercise ECG before elective noncardiac surgery provides an
objective measurement of functional capacity and the potential to
identify the likelihood of perioperative myocardial ischemia in
patients with a low ischemic threshold .
The risks of perioperative cardiac events and adverse long-term
outcome are significantly increased in patients with abnormal
exercise ECG results at low workloads
EVALUATION OF VENTRICULAR
Exercise testing provokes repetitive VPC in most patients with a
history of sustained ventricular tachyarrhythmia, and in
approximately 10 to 15 percent of such patients, spontaneously
occurring arrhythmias are observed only during exercise testing.
Frequent VPC that occurs in the early postexercise phase is
associated with a worse long-term prognosis than VPC that occur
only during exercise.
Supraventricular premature beats induced by exercise are observed
in 4 to 10 percent of normal persons and in up to 40 percent of
patients with underlying heart disease.
Sustained supraventricular tachyarrhythmias occur in only 1 to 2
percent of patients, although the frequency may approach as much
as 10 to 15 percent in patients.
The presence of supraventricular arrhythmias is not
diagnostic for ischemic heart disease, nor do they predict
adverse long-term cardiovascular outcomes
Patients with chronic atrial fibrillation tend to have a rapid ventricular
response in the initial stages of exercise, and 60 to 70 percent of
the total change in heart rate usually occurs within the first few
minutes of exercise.
The effect of digitalis preparations and beta-adrenergic and
selected calcium antagonists, such as diltiazem, on attenuating this
rapid increase in heart rate for individual patients can be measured
using exercise testing.
SINUS NODE DYSFUNCTION.
In general, patients with sinus node dysfunction have a lower heart
rate at submaximal and maximal workloads compared with control
However, as many as 40 to 50 percent of patients will have a
normal exercise heart rate response.
Exercise testing may help determine the need for atrioventricular
(AV) sequential pacing in selected patients.
In patients with congenital AV block, exercise-induced heart rates
are low and some patients develop symptomatic rapid junctional
rhythms that can be suppressed with DDD devices .
In patients with acquired conduction disease, exercise can
occasionally elicit advanced AV block.
LEFT BUNDLE BRANCH BLOCK.
Exercise-induced ST segment depression is found in most patients
with left bundle branch block (LBBB) and cannot be used as a
diagnostic or prognostic indicator, regardless of the degree of ST
relative risk of death or other major cardiac events in patients with
exercise-induced LBBB is increased approximately threefold over
the risk in patients without this abnormality .
The development of ischemic ST segment depression before the
LBBB pattern appears or in the recovery phase after the LBBB has
resolved does not attenuate the diagnostic yield of the ST segment
RIGHT BUNDLE BRANCH BLOCK.
The resting ECG in patients with RBBB is frequently associated with
T wave and ST segment changes in the early anterior precordial
leads (V1 to V3).
Exercise-induced ST depression in leads V1 to V4 is a common
finding in patients with RBBB and is nondiagnostic.
The new development of exercise-induced ST segment depression
in leads V5 and V6 or leads 2 and aVF, reduced exercise capacity,
and inability to increase systolic blood pressure adequately.
The new development of exercise-induced RBBB is relatively
uncommon, occurring in approximately 0.1 percent of test results.
The presence of WPW syndrome invalidates the use of ST segment
analysis as a diagnostic method for detecting CAD in preexcited as
well as normally conducted beats; false-positive ischemic changes
are frequently registered.
In patients with persistent preexcitation, exercise may normalize the
QRS complex, with disappearance of the delta wave in 20 to 50
percent of cases .
Abrupt disappearance of the delta wave is presumptive evidence of
a longer anterograde effective refractory period of the accessory
Progressive disappearance of the delta wave is less reassuring and
occurs when the improvement in AV node conduction is greater
than in the accessory pathway;
This finding does not preclude a possible significant or even critical
shortening of the anterograde effective refractory period in the
accessory pathway under the influence of sympathetic stimulation.
The presence of Wolff-Parkinson-White syndrome does not cause a
limitation of physical work capacity.
The diagnostic accuracy of exercise-induced ST segment
depression for obstructive CAD is less in women than in men.
Women tend to have a greater release of catecholamines during
exercise, which could potentiate coronary vasoconstriction and
augment the incidence of abnormal exercise ECG results.
False-positive results have been reported to be more common
during menses or preovulation, and in postmenopausal women on
In asymptomatic women, a low exercise capacity, low heart rate
recovery, and failure to reach target heart rate are more important
predictors of outcome than exercise-induced ECG changes.
The exercise ECG remains the recommended test of first choice for
the assessment of symptomatic, intermediate-risk women who can
exercise and have normal findings on a resting ECG.
Exercise testing has been used in an attempt to identify patients
who have an abnormal blood pressure response and are destined
subsequently to develop hypertension.
In asymptomatic normotensive individuals, Exaggerated exercise
systolic and diastolic blood pressure response during exercise or
Exaggerated peak systolic blood pressure response to 214 mmHg
or higher or an elevated systolic or Diastolic blood pressure at the
third minute of recovery is associated with significant increased
long-term risk of hypertension .
Severe systemic hypertension may interfere with subendocardial
perfusion and cause exercise-induced ST segment depression in
the absence of atherosclerosis, even when the resting ECG does
not show significant ST or T wave changes.
Coronary Bypass Grafting
The degree of improvement in exercise-induced myocardial
ischemia and aerobic capacity after CABG depends in part on the
degree of revascularization achieved and on left ventricular
Exercise-induced ischemic ST segment depression may persist
when incomplete revascularization is achieved, albeit at higher
It also may persist in approximately 5 percent of patients in whom
complete revascularization has been achieved.
Percutaneous Coronary Intervention
In the early post-PCI phase (less than 1 month), an abnormal
exercise ECG result may be secondary to a suboptimal result,
impaired coronary vascular reserve in a successfully dilated vessel,
or incomplete revascularization.
Thus, exercise electrocardiography has a low diagnostic accuracy
to detect restenosis or an incomplete dilation in the periprocedural
A 6- to 12-month postprocedure test allows sufficient time to
document restenosis should it occur and allows the dilated vessel
an opportunity to heal.
Serial conversion of an initially normal exercise test result after PCI
to an abnormal result in the initial 6 months after the procedure,
particularly when it occurs at a lower exercise workload, is usually
associated with restenosis.
In patients with chronic severe mitral or aortic regurgitation, the
diagnostic role of exercise testing is limited to the evaluation of
exercise capacity in patients with equivocal symptoms.
The exercise test carries a class IIa indication for
assessing response to therapy and for risk
To define the presence of exercise-induced outflow tract obstruction
via Doppler echocardiography in patients with no gradient at rest.
The second is identifying patients with coexistent CAD, and
The third is detecting patients with the high-risk indicator of an
abnormal blood pressure response.
always inducible by a maximal exercise test and is frequently not
inducible with programmed electrical stimulation.
determine the patient’s response to treatment,namely, beta
changes in the QT interval with exercise can be useful in identifying
and stratifying patients with this syndrome.
prolongation of an already prolonged QT interval with exercise is
typical of long-QT1 syndrome.
Long-QT2 syndrome has normal shortening,
long-QT3 syndrome has supranormal shortening of the QT interval
augmentation of early precordial ST-segment elevation early in
recovery from exercise is both specific to Brugada syndrome and a
predictor of a poor prognosis.