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False-positive exercise test in the presence of the Wolff-Parkinson-White syndrome
False-positive exercise test in the presence of the Wolff-Parkinson-White
syndrome
Peter C. Gazes, M.D.” Charleston. S. C.
I
t has been approximately 38 years since the Wolff-Parkinson-White syndrome (WPW or pre-excitation) was described. However, the incidence of incorrect electrocardiographic interpretation related to this entity remains inappropriately high. Wolff, Parkinson, and White* estimated that one third of the cases are incorrectly diagnosed by the physicians who first see them. Incorrect diagnoses of myocardial infarction, bundle branch block, ventricular hypertrophies, and ventricular tachycardia have been made. This report emphasizes that a false-positive exercise test often occurs in the presence of the WPW syndrome accounting for the mistaken diagnosis of ischemic heart disease. A double two-step Master’s exercise test was performed on 23 patients between the ages of 17 and 59 with the WPW syndrome by a method previously described.2 These patients were asymptomatic and had no evidence of heart disease.
Fig. 1. Two patients (.-1 and B), 17 years and 29 years of age, respectively, with the WPW syndrome. After exercise right angle S-T depres&n with T-wave inversion occurred. From the Department of Medicine. Media1 College This study was supported by Cardiovascular Training Received for publication Nov. 11. 1968. *Professor of Medicine, Chief, Division of Cardiology.
Vol.
78, No.
1, pp. 13-15
July,
1969
of South Carolina, 80 Barre St.. Ci~arleuton. Grant 5 T2 HtiSO.?O-I i from tlx National
American
Heart
S. C. LWOI. lIeart Invitute.
JoGrnnl
13
Fig. 2. A do-year-old conduction. During occur in the normal
patient with the WPW syndrome. After exercise there is intermittent normal and WPW the WPW conduction, S-T depression with inverted T waves can be seen which did not conducted beats.
Fig. 3. A 42-year-old patient with WPW alternating WPW and normal conduction, plexes.
syndrome. Note in the Va and Ve leads after exercise that there is with positive exercise changes occurring only in the WPW com-
Fcilse-positive
Results
Twenty of these patients had a positive double Master’s exercise test characterized by right angle S-T segment depression of 1 mm. or more with or without inversion of the T waves (Fig. 1). Figs. 2 and 3 depict two patients with intermittent WPW and normal conduction occurring after exercise with positive exercise changes seen only during the WPW conduction. Discussion
Today many forms of electrocardiographic exercise tests (bIaster’s,3 near maximum,4 or maximum exercises) are being performed especially on patients with atypical chest pain. Regardless of the type of exercise test, we must be aware of false-positive changes. Such false-positive tests have been known to occur in the presence of digitalis, bundle branch block, hypertrophies, healed pericarditis, and autonomic changes. Lamb6 described one subject with multiple variation of WPW conduction \vho had a false-positive exercise test. In the presence of the WPW syndrome positive exercise changes frequently occur and are probably secondar) changes as are seen after exercise in patients with bundle branch block. These are secondary ST-T changes opposite in direction and proportionate in magnitude to the main deflection of the QRS complex in area. Often physicians do not recognize the WPW syndrome in the resting tracing
test in WP W syndrome
15
and the error is compounded Ivitll ;I positive Master’s exercise test. Summary
Twenty-three patients with electrocardiographic findings typical of the WPW syndrome, but no evidence of heart disease, were exercised, utilizing a double two-step Alaster’s exercise test. Twenty of these had positive changes. In the presence of the WPW syndrome the electrocardiographic exercise test is of no value in vien of the frequent false-positive cltanges. I wish to thank Dr. 1. A. Morrish. ing t&e to include
Dr. J. N. Berry, Atlanta, Ga., and Brandenton, Fla., for ec1t.h allowone of their patients in this study.
REFERENCES I.
2.
3. 4.
3.
6.
\Volff, I,., Parkinson, J., and LVhite, 1’. I).: Bundle-branch block with short P-R interval in healthy \oung people prone to paroxysmal tach>,cardia, AM. HEAKT J. 5:685, 1930. Gazes, P. C., Culler. M. Ii., and Stokes, J. K.: The diagnosis of angina pectoris, :IM. kiIc.kKT J. 67:830, 1964. Master, A. >‘I.: The Master two-step test, AM. HEART J. 75:809, 1968. Sheffield. L. T.. Holt. I. H.. and Reeves. T. I.: Exercise’gradei by he&t r&e in electrc&d~ographic testing for angina pectoris, Circulntiolk 32:622, 1965. Doan, A. E., Peterson, L). K., Blackm;m. J. I<. , and Bruce. I<. &4.: Mvocardial kchenlia alter maximal exercise in healthy men. :]\I. tIEART J. 69:11, 1965. Lamb, I,.: Multiple variations of \Z.olff-I’arkinson-\Vhite conduction in one subjert. Intermittent normal conduction and a f&e-positive exercise test. .L\m. J. Cardiol. ,t:.M, 1959.
syndrome
Peter C. Gazes, M.D.” Charleston. S. C.
I
t has been approximately 38 years since the Wolff-Parkinson-White syndrome (WPW or pre-excitation) was described. However, the incidence of incorrect electrocardiographic interpretation related to this entity remains inappropriately high. Wolff, Parkinson, and White* estimated that one third of the cases are incorrectly diagnosed by the physicians who first see them. Incorrect diagnoses of myocardial infarction, bundle branch block, ventricular hypertrophies, and ventricular tachycardia have been made. This report emphasizes that a false-positive exercise test often occurs in the presence of the WPW syndrome accounting for the mistaken diagnosis of ischemic heart disease. A double two-step Master’s exercise test was performed on 23 patients between the ages of 17 and 59 with the WPW syndrome by a method previously described.2 These patients were asymptomatic and had no evidence of heart disease.
Fig. 1. Two patients (.-1 and B), 17 years and 29 years of age, respectively, with the WPW syndrome. After exercise right angle S-T depres&n with T-wave inversion occurred. From the Department of Medicine. Media1 College This study was supported by Cardiovascular Training Received for publication Nov. 11. 1968. *Professor of Medicine, Chief, Division of Cardiology.
Vol.
78, No.
1, pp. 13-15
July,
1969
of South Carolina, 80 Barre St.. Ci~arleuton. Grant 5 T2 HtiSO.?O-I i from tlx National
American
Heart
S. C. LWOI. lIeart Invitute.
JoGrnnl
13
Fig. 2. A do-year-old conduction. During occur in the normal
patient with the WPW syndrome. After exercise there is intermittent normal and WPW the WPW conduction, S-T depression with inverted T waves can be seen which did not conducted beats.
Fig. 3. A 42-year-old patient with WPW alternating WPW and normal conduction, plexes.
syndrome. Note in the Va and Ve leads after exercise that there is with positive exercise changes occurring only in the WPW com-
Fcilse-positive
Results
Twenty of these patients had a positive double Master’s exercise test characterized by right angle S-T segment depression of 1 mm. or more with or without inversion of the T waves (Fig. 1). Figs. 2 and 3 depict two patients with intermittent WPW and normal conduction occurring after exercise with positive exercise changes seen only during the WPW conduction. Discussion
Today many forms of electrocardiographic exercise tests (bIaster’s,3 near maximum,4 or maximum exercises) are being performed especially on patients with atypical chest pain. Regardless of the type of exercise test, we must be aware of false-positive changes. Such false-positive tests have been known to occur in the presence of digitalis, bundle branch block, hypertrophies, healed pericarditis, and autonomic changes. Lamb6 described one subject with multiple variation of WPW conduction \vho had a false-positive exercise test. In the presence of the WPW syndrome positive exercise changes frequently occur and are probably secondar) changes as are seen after exercise in patients with bundle branch block. These are secondary ST-T changes opposite in direction and proportionate in magnitude to the main deflection of the QRS complex in area. Often physicians do not recognize the WPW syndrome in the resting tracing
test in WP W syndrome
15
and the error is compounded Ivitll ;I positive Master’s exercise test. Summary
Twenty-three patients with electrocardiographic findings typical of the WPW syndrome, but no evidence of heart disease, were exercised, utilizing a double two-step Alaster’s exercise test. Twenty of these had positive changes. In the presence of the WPW syndrome the electrocardiographic exercise test is of no value in vien of the frequent false-positive cltanges. I wish to thank Dr. 1. A. Morrish. ing t&e to include
Dr. J. N. Berry, Atlanta, Ga., and Brandenton, Fla., for ec1t.h allowone of their patients in this study.
REFERENCES I.
2.
3. 4.
3.
6.
\Volff, I,., Parkinson, J., and LVhite, 1’. I).: Bundle-branch block with short P-R interval in healthy \oung people prone to paroxysmal tach>,cardia, AM. HEAKT J. 5:685, 1930. Gazes, P. C., Culler. M. Ii., and Stokes, J. K.: The diagnosis of angina pectoris, :IM. kiIc.kKT J. 67:830, 1964. Master, A. >‘I.: The Master two-step test, AM. HEART J. 75:809, 1968. Sheffield. L. T.. Holt. I. H.. and Reeves. T. I.: Exercise’gradei by he&t r&e in electrc&d~ographic testing for angina pectoris, Circulntiolk 32:622, 1965. Doan, A. E., Peterson, L). K., Blackm;m. J. I<. , and Bruce. I<. &4.: Mvocardial kchenlia alter maximal exercise in healthy men. :]\I. tIEART J. 69:11, 1965. Lamb, I,.: Multiple variations of \Z.olff-I’arkinson-\Vhite conduction in one subjert. Intermittent normal conduction and a f&e-positive exercise test. .L\m. J. Cardiol. ,t:.M, 1959.