Abnormal Electrocardiographic Responses to Exercise in Patients Referred for Noninvasive Evaluation of Occlusive Peripheral Arterial Disease
AGENOR SILVESTRE, MD ARTUR DESA’NETO, MD JOHN M. JOHNSON, MD KENNETH B. DESSER, MD, FACC ALBERT0 BENCHIMOL, MD, FACC Phoenix, Arizona
From The Institute for Cardiovascular Diseases and the Peripheral Vascular Laboratory, Good Samaritan Hospital, Phoenix, Arizona. This study was supported in part by the E. Nichols and Kim Sigsworth Memorial Funds and The Institute for Cardiovascular Diseases, Inc., Phoenix, Arizona. Manuscript received August 2. 1978; revised manuscript received October 23, 1978, accepted October 25, 1978. Address for reprints: Albert0 Benchimol, MD, Good Samaritan Hospital, P. 0. Box 2989, Phoenix, Arizona 85062.
Fifty consecutive patients were referred to the noninvasive laboratory for evaluation of suspected peripheral vascular disease. There were 30 men and 20 women aged 27 to 88 years (mean 83). Measurement of cardiovascular risk factors revealed the foliowlng distributions: cigarette smoking 90 percent, hypertension 28 percent, diabetes meliltus 22 percent and hyperlipidemia 8 percent. Eight patients had a history of angina pectoris, 7 a prior myocardiai infarction, 5 a cerebrovascular accident and 11 prior peripheral arterial revascularization surgery. Evaluation detected 32 patients (84 percent) with occlusive arterial disease of the lower limbs. Lead II of the electrocardiogram was monitored during and 1,2,3,4, and 5 minutes after treadmill exercise with a limiting grade of 10 percent at 2.5 miles/hour. The mean resting and maximal heart rates for the study group were, respectively, 78 and 108 beats/min. The average treadmill speed attained was 1.9 miles/hour at a mean duration of 3.8 minutes. Thirty-seven subjects (74 percent) had normal electrocardiographic responses to exercise. Of 13 patients (28 percent) with an abnormal exercise electrocardiogram, 7 had possible ischemic S-T segment responses. Six subjects manifested frequent premature ventricular complexes during exercise. Four other patients had abnormal S-T segments in the resting electrocardiogram (two had a pattern of left bundle branch block, and two a pattern of left ventricular hypertrophy and strain). A survey of 80 peripheral vascular laboratories in the United States revealed that only 29 percent of the responding 34 centers routinely performed electrocardiographic monitoring during exercise testing. It is concluded that (1) electrocardiographic monitoring during exercise in the peripheral vascular laboratory can provide useful information regarding S-T segment responses, (2) abnormal S-T segment responses in patients with suspected peripheral vascular disease are frequently manifested at low levels of work load, and (3) such routine monitoring should be performed for patient safety.
It is generally recognized that the most common and important form of occlusive peripheral arterial disease is arteriosclerosis obliterans,l and the frequent association of atherosclerotic involvement of the lower limbs and coronary artery disease has been well established. In light of the large incidence of cerebrovascular disease as well as aortic involvement in patients with coronary artery disease, there should be little doubt that the association of coronary artery and peripheral vascular disease occurs because the same pathologic process is involved in each.‘-” Intermittent claudication is the most characteristic symptom of arteriosclerosis obliterans. In the Framingham study,3 the clinical manifestations of coronary atherosclerosis were four times more common than intermittent claudication. The incidence of both increased with age, and the onset of symptoms occurred approximately 10 years earlier in men than in women.3,4
April 1979
The American Journal of CARDIOLOGY
Volume 43
713
EXERCISE ELECTROCARDIOGRAMIN PERIPHERALARTERIAL DISEASE-SILVESTRE ET AL
TABLE I Prolocoi for Exercise Evaluation of Peripheral Arterial Disease 1. Bilateral upper and lower limb blood pressure measurement, Doppler ultrasonic flow, pulse volumes and grading by palpation performed in resting state. 2. Modified lead II of electrocardiogram recorded in resting state. 3. Treadmill testing initiated at 1.7 miles/hour (10 percent grade) and araduallv brouaht UD to a speed of 2. 5 miles/hour as tolerated by ihe patient. A query regarding tolerance offered every 30 seconds. Lead II monitored. 4. Termination of test after appearance of limiting symptoms, abnormal electrocardiographic response or a maximal 5 minutes of exercise. 5. Step 1 repeated immediately after the stress test. recorded at 1, 2, 3, 4 and 5 lead 6. Modified . -. II of .electrocardiogram ... . mtnutes arter treaamlll exerctse.
All subjects were referred for study because of one of the following complaints: exertional leg cramps or fatigue and paresthesias or pallor of the pedal digits. Eleven of 50 (22 percent) had angiographically documented peripheral vascular disease and a history of prior surgical intervention for this disorder. All patients were questioned regarding clinical symptoms as well as a past or current history of smoking habits, hypertension, diabetes, hyperlipidemia, angina pectoris, myocardial infarction or cerebrovascular disease. Exercise protocol (Table I): A modified lead II electrocardiogram was recorded before exercise, at the completion of each minute of treadmill testing and every minute from the 1st to the 5th minute after completion of the session. Four patients had abnormal S-T segment changes in the I2 lead electrocardiogram (two with a pattern of complete left bundle branch block and two with a pattern of left ventricular hypertrophy and strain) and were excluded from analysis because of repolarization alterations during exercise. Pulse volume recordings and systolic segmental arterial pressures were obtained with pneumatic cuffs applied to the
Coronary artery disease is the leading cause of morbidity and mortality in patients with occlusive peripheral arterial disease. Tomatis et al.5 demonstrated angiographically significant coronary artery disease in 47 percent of 72 patients with arteriosclerosis obliterans. Lukasik and Liszewska-Pfejfers recently demonstrated with noninvasive techniques an 18.8 percent prevalence rate of peripheral vascular disease in patients with coronary disease. Thirty-four percent of these subjects did not have symptoms compatible with ischemia of the lower limbs. With the development of refined noninvasive methods for early detection and anatomic characterization of arterial occlusion, treadmill exercise protocols are now routinely utilized in peripheral vascular laboratories. In this study therefore we investigated prospectively the incidence of abnormal electrocardiographic responses in patients undergoing treadmill exercise for the investigation of occlusive peripheral arterial disease.
Methods Patients: Fifty consecutive patients referred to the peripheral vascular laboratory of this hospital for the evaluation of peripheral arterial disease constituted the study group. There were 30 men and 20 women whose ages ranged from 27 to 88 years (mean 63). They represented the total patient population so investigated from October 1977 to March 1978.
lower limbs, which were connected to a pulse volume recorder (Life Sciences, Inc.). A unidirectional Doppler transducer (model 802A, Parks Electronics, Inc.) emitting an ultrasonic frequency of 9.2 megahertz was used to assess the arterial flow dynamic characteristics. All measurements were obtained in the resting state and immediately after the patients exercised on the treadmill. The end points for testing included symptoms of lower limb disease, the ability to sustain exercise to a limiting grade of 10 percent at 2.5 miles/hour for 5 minutes, and abnormal electrocardiographic changes; the latter included 2 mm of downsloping or horizontal S-T segment depression, salvos of ventricular extrasystoles or a marked increase in the frequency of premature complexes over those in the control tracing.
Results The prevalence of cardiovascular risk factors and the pertinent associated diseases or symptoms are summarized in Table II for the 50 consecutive patients referred to our laboratory for the evaluation of vascular disease and in Table III for the 32 patients (64 percent) found to have occlusive disease. Exercise results: Analysis of modified lead II of the electrocardiogram before, during and 1, 2, 3, 4 and 5 minutes after treadmill exercise revealed that the total group of patients had a mean resting heart rate of 78 beats/min and a mean heart rate of 106 beats/min at an average attained speed of 1.9 miles/hour after a mean
TABLE iii TABLE ii
Provalence of Risk Factors and Associated Direale Processes or Symptoms in 32 Patients With the Noninvasive Diagnosis of Occlusive Peripheral Arterial Disease
Prevalence of Risk Factors and Associated Disease Processes or Symptoms in 50 Patients Referred for Evaluation of Peripheral Arterial Circulation
Patients
Patlentsno. Cigarette smoking Hypertension Diabetes mellitus Hyperlipidemia History of angina pectoris Prior myocardial infarction Previous cerebrovascular accident
714
April 1979
%
45 :: 3 6 :
The American Journal ol CARDIOLOGY
Cigarette smoking Hypertension Diabetes mellitus Hyperlipldemia History of angina pectorls Prior myocardlal infarction Previous cerebrovascular accident
6 16 14 10
Volume 43
no.
%
30 14
93.7 43.3 25
! 5 5
18 1516 6.2
EXERCISE ELECTROCARDIOGRAMIN PERIPHERALARTERIAL DISEASE-SILVESTRE ET AL.
FffiURE 1. Control lead II (LII) electrocardioyam, recorded during sitting and standing, from a 68 year old man with no history of angina pectoris or myocardial infarction. At 4 minutes of treadmill exercise (EX) (2.25 miles/hour, 10 percent grade) there is S-T segment depression suggesting myocardial ischemia.
exercise duration of 3.8 minutes. At this low work load, corresponding to approximately 63 percent of the predicted maximal heart rate for the mean age of the group, 13 patients (26 percent) had an abnormal electrocardiographic response. Seven patients (five men and two women) (14 percent) manifested S-T segment depression suggestive of myocardial ischemia7 and six patients (four men and two women) (12 percent) manifested frequent premature ventricular complexes (Fig. 1 and 2). “Frequent” was defined as a rate of occurrence exceeding one premature complex per four sinus complexes. To ascertain whether peripheral vascular laboratories utilizing treadmill exercise protocols routinely monitor the electrocardiogram during testing, we forwarded a questionnaire to 60 institutions. Of 34 centers responding to the inquiry, only 10 (29 percent) were recording the electrocardiograms of patients being evaluated with exercise testing. Discussion
The contraindications for submaximal treadmill stress testing in patients with suspected coronary artery disease have been fairly well agreed on, and only some of them can be recognized by means of a resting 12 lead electrocardiogram. Furthermore, in many instances termination of the test is based solely on the electrocardiographic response to exercise.7 The vast majority of subjects undergoing noninvasive evaluation of peripheral arterial circulation are not stressed to levels that approximate those utilized in submaximal exercise stress tests for assessing myocardial ischemia. Clinical implications of data: Our data indicate that a substantial number of patients referred to laboratories investigating the peripheral arterial circulation may have abnormal responses to mild degrees of exercise. These findings have both diagnostic and therapeutic implications. Application of continuous electrocardiographic recording during such testing would appear to be useful in identifying a number of patients with concomitant ischemic heart disease. The achievement of an average heart rate of only 106 beats/min suggests that these older patients with suspected or confirmed peripheral arterial disease may have a low ischemic threshold. Alternatively, such a
FIGURE 2. Control electrocardiogram (LII) from a 68 year old man with occlusive peripheral arterial disease and no history of angina pectoris or myocardial infarction. The tracing obtained at rest shows S-T segment and T wave abnormalities with occasional premature ventricular complexes. At 1 minute of exercise (1.7 miles/hour, 10 percent grade) salvos of extrasystoles are noted. One minute after termination of the test, ventricular bigeminy and paired premature complexes are recorded. Five minutes after exercise there were only two premature ventricular complexes/min.
heart rate may connote a fair degree of activity in a study group of patients who, because of their peripheral vascular disease, do not achieve an average exercise range in their daily activities. The S-T segment depression and the development of ventricular ectopy in 26 percent of the study group provide strong evidence that electrocardiographic monitoring should be performed in all subjects referred for exercise evaluation of the peripheral arterial system. Although none of the 50 patients had a cardiac arrest or sustained chest pain as a consequence of exercise, the potential for such events is clear. Patient safety would appear to be a major byproduct of exercise electrocardiographic monitoring in this group. Clinical application: Less than one third of responding peripheral vascular laboratories indicated that elect,rocardiographic monitoring was routinely applied in patients referred for the diagnosis of peripheral vascular disease. Universal application of such monitoring would provide a fruitful area for research into the coexistence of ischemic heart disease and occlusive peripheral arterial disease. Additionally, our data imply that resuscitative equipment and staff members well versed in the management of acute cardiac emergencies should be used at such centers. Concomitant electrocardiographic monitoring is used primarily for safety rather than for diagnostic purposes in these patients with suspected peripheral vascular disease. It should be appreciated by those working in peripheral vascular disease laboratories that associated coronary atherosclerotic heart disease may provide the limiting factor in the exercise testing even though the patients manifest no symptoms of lower limb disease during exercise. Furthermore, the electrocardiographic changes described here are only suggestive rather than specifically diagnostic of myocardial ischemia. Acknowledgment
We gratefully acknowledge the technical assistance of Kathy Tustison, Carole Crevier, Sydney Peebles, Betty Kjellberg and Saundra Morgan.
April 1979
The American Journal of CARDIOLOGY
Volume 43
715
EXERCISE ELECTROCARDIOGRAMIN PERIPHERAL ARTERIAL DISEASE-SILVESTRE ET AL.
References Spittell JA Jr, DeWolfe V, Hume M, Wlnsor 1, Wylie EJ: Prevention and early detection of peripheral vascular disease. Sub-committee on peripheral vascutar disease. Report of Inter-Society Commission for Heart Disease Resources. Circulation 42:A-43-A-45, 1970 (revised August 1972) Juergens JL, Barker NW, Hines EA Jr: Arteriosclerosis obliterans: review of 520 cases with special reference to pathogenic and prognostic factors. Circulation 21:188-195, 1960 Kannel WE, Sklnner JJ Jr, Schwartz MJ, Shurtleff D: Intermittent claudication. Incidence in the Framingham study. Circulation 41: 875-883. 1970
716
April 1979
The American Journal of CARDIOLOGY
4. Kannel WE, Shurtleff D: The natural history of arteriosclerosis obliterans. Cardiovasc Clin 3:38-52, 197 1 5. Tomeils LA, Flerens EE, Verbrugge GP: Evaluation of surgical risk in peripheral vascular disease by coronary arteriography: a series of 100 cases. Surgery 71:429-435, 1972 6. Lukaslk E, Llszewska-Pfejfer D: Obliterative arteriosclerosis of extremities in patients with coronary heart disease. Cor Vasa 19: 176-183, 1977 7. Ellestad MH: Stress Testing. Philadelphia, FA Davis, 1975, p 15, 16, 100
Volume 43
AGENOR SILVESTRE, MD ARTUR DESA’NETO, MD JOHN M. JOHNSON, MD KENNETH B. DESSER, MD, FACC ALBERT0 BENCHIMOL, MD, FACC Phoenix, Arizona
From The Institute for Cardiovascular Diseases and the Peripheral Vascular Laboratory, Good Samaritan Hospital, Phoenix, Arizona. This study was supported in part by the E. Nichols and Kim Sigsworth Memorial Funds and The Institute for Cardiovascular Diseases, Inc., Phoenix, Arizona. Manuscript received August 2. 1978; revised manuscript received October 23, 1978, accepted October 25, 1978. Address for reprints: Albert0 Benchimol, MD, Good Samaritan Hospital, P. 0. Box 2989, Phoenix, Arizona 85062.
Fifty consecutive patients were referred to the noninvasive laboratory for evaluation of suspected peripheral vascular disease. There were 30 men and 20 women aged 27 to 88 years (mean 83). Measurement of cardiovascular risk factors revealed the foliowlng distributions: cigarette smoking 90 percent, hypertension 28 percent, diabetes meliltus 22 percent and hyperlipidemia 8 percent. Eight patients had a history of angina pectoris, 7 a prior myocardiai infarction, 5 a cerebrovascular accident and 11 prior peripheral arterial revascularization surgery. Evaluation detected 32 patients (84 percent) with occlusive arterial disease of the lower limbs. Lead II of the electrocardiogram was monitored during and 1,2,3,4, and 5 minutes after treadmill exercise with a limiting grade of 10 percent at 2.5 miles/hour. The mean resting and maximal heart rates for the study group were, respectively, 78 and 108 beats/min. The average treadmill speed attained was 1.9 miles/hour at a mean duration of 3.8 minutes. Thirty-seven subjects (74 percent) had normal electrocardiographic responses to exercise. Of 13 patients (28 percent) with an abnormal exercise electrocardiogram, 7 had possible ischemic S-T segment responses. Six subjects manifested frequent premature ventricular complexes during exercise. Four other patients had abnormal S-T segments in the resting electrocardiogram (two had a pattern of left bundle branch block, and two a pattern of left ventricular hypertrophy and strain). A survey of 80 peripheral vascular laboratories in the United States revealed that only 29 percent of the responding 34 centers routinely performed electrocardiographic monitoring during exercise testing. It is concluded that (1) electrocardiographic monitoring during exercise in the peripheral vascular laboratory can provide useful information regarding S-T segment responses, (2) abnormal S-T segment responses in patients with suspected peripheral vascular disease are frequently manifested at low levels of work load, and (3) such routine monitoring should be performed for patient safety.
It is generally recognized that the most common and important form of occlusive peripheral arterial disease is arteriosclerosis obliterans,l and the frequent association of atherosclerotic involvement of the lower limbs and coronary artery disease has been well established. In light of the large incidence of cerebrovascular disease as well as aortic involvement in patients with coronary artery disease, there should be little doubt that the association of coronary artery and peripheral vascular disease occurs because the same pathologic process is involved in each.‘-” Intermittent claudication is the most characteristic symptom of arteriosclerosis obliterans. In the Framingham study,3 the clinical manifestations of coronary atherosclerosis were four times more common than intermittent claudication. The incidence of both increased with age, and the onset of symptoms occurred approximately 10 years earlier in men than in women.3,4
April 1979
The American Journal of CARDIOLOGY
Volume 43
713
EXERCISE ELECTROCARDIOGRAMIN PERIPHERALARTERIAL DISEASE-SILVESTRE ET AL
TABLE I Prolocoi for Exercise Evaluation of Peripheral Arterial Disease 1. Bilateral upper and lower limb blood pressure measurement, Doppler ultrasonic flow, pulse volumes and grading by palpation performed in resting state. 2. Modified lead II of electrocardiogram recorded in resting state. 3. Treadmill testing initiated at 1.7 miles/hour (10 percent grade) and araduallv brouaht UD to a speed of 2. 5 miles/hour as tolerated by ihe patient. A query regarding tolerance offered every 30 seconds. Lead II monitored. 4. Termination of test after appearance of limiting symptoms, abnormal electrocardiographic response or a maximal 5 minutes of exercise. 5. Step 1 repeated immediately after the stress test. recorded at 1, 2, 3, 4 and 5 lead 6. Modified . -. II of .electrocardiogram ... . mtnutes arter treaamlll exerctse.
All subjects were referred for study because of one of the following complaints: exertional leg cramps or fatigue and paresthesias or pallor of the pedal digits. Eleven of 50 (22 percent) had angiographically documented peripheral vascular disease and a history of prior surgical intervention for this disorder. All patients were questioned regarding clinical symptoms as well as a past or current history of smoking habits, hypertension, diabetes, hyperlipidemia, angina pectoris, myocardial infarction or cerebrovascular disease. Exercise protocol (Table I): A modified lead II electrocardiogram was recorded before exercise, at the completion of each minute of treadmill testing and every minute from the 1st to the 5th minute after completion of the session. Four patients had abnormal S-T segment changes in the I2 lead electrocardiogram (two with a pattern of complete left bundle branch block and two with a pattern of left ventricular hypertrophy and strain) and were excluded from analysis because of repolarization alterations during exercise. Pulse volume recordings and systolic segmental arterial pressures were obtained with pneumatic cuffs applied to the
Coronary artery disease is the leading cause of morbidity and mortality in patients with occlusive peripheral arterial disease. Tomatis et al.5 demonstrated angiographically significant coronary artery disease in 47 percent of 72 patients with arteriosclerosis obliterans. Lukasik and Liszewska-Pfejfers recently demonstrated with noninvasive techniques an 18.8 percent prevalence rate of peripheral vascular disease in patients with coronary disease. Thirty-four percent of these subjects did not have symptoms compatible with ischemia of the lower limbs. With the development of refined noninvasive methods for early detection and anatomic characterization of arterial occlusion, treadmill exercise protocols are now routinely utilized in peripheral vascular laboratories. In this study therefore we investigated prospectively the incidence of abnormal electrocardiographic responses in patients undergoing treadmill exercise for the investigation of occlusive peripheral arterial disease.
Methods Patients: Fifty consecutive patients referred to the peripheral vascular laboratory of this hospital for the evaluation of peripheral arterial disease constituted the study group. There were 30 men and 20 women whose ages ranged from 27 to 88 years (mean 63). They represented the total patient population so investigated from October 1977 to March 1978.
lower limbs, which were connected to a pulse volume recorder (Life Sciences, Inc.). A unidirectional Doppler transducer (model 802A, Parks Electronics, Inc.) emitting an ultrasonic frequency of 9.2 megahertz was used to assess the arterial flow dynamic characteristics. All measurements were obtained in the resting state and immediately after the patients exercised on the treadmill. The end points for testing included symptoms of lower limb disease, the ability to sustain exercise to a limiting grade of 10 percent at 2.5 miles/hour for 5 minutes, and abnormal electrocardiographic changes; the latter included 2 mm of downsloping or horizontal S-T segment depression, salvos of ventricular extrasystoles or a marked increase in the frequency of premature complexes over those in the control tracing.
Results The prevalence of cardiovascular risk factors and the pertinent associated diseases or symptoms are summarized in Table II for the 50 consecutive patients referred to our laboratory for the evaluation of vascular disease and in Table III for the 32 patients (64 percent) found to have occlusive disease. Exercise results: Analysis of modified lead II of the electrocardiogram before, during and 1, 2, 3, 4 and 5 minutes after treadmill exercise revealed that the total group of patients had a mean resting heart rate of 78 beats/min and a mean heart rate of 106 beats/min at an average attained speed of 1.9 miles/hour after a mean
TABLE iii TABLE ii
Provalence of Risk Factors and Associated Direale Processes or Symptoms in 32 Patients With the Noninvasive Diagnosis of Occlusive Peripheral Arterial Disease
Prevalence of Risk Factors and Associated Disease Processes or Symptoms in 50 Patients Referred for Evaluation of Peripheral Arterial Circulation
Patients
Patlentsno. Cigarette smoking Hypertension Diabetes mellitus Hyperlipidemia History of angina pectoris Prior myocardial infarction Previous cerebrovascular accident
714
April 1979
%
45 :: 3 6 :
The American Journal ol CARDIOLOGY
Cigarette smoking Hypertension Diabetes mellitus Hyperlipldemia History of angina pectorls Prior myocardlal infarction Previous cerebrovascular accident
6 16 14 10
Volume 43
no.
%
30 14
93.7 43.3 25
! 5 5
18 1516 6.2
EXERCISE ELECTROCARDIOGRAMIN PERIPHERALARTERIAL DISEASE-SILVESTRE ET AL.
FffiURE 1. Control lead II (LII) electrocardioyam, recorded during sitting and standing, from a 68 year old man with no history of angina pectoris or myocardial infarction. At 4 minutes of treadmill exercise (EX) (2.25 miles/hour, 10 percent grade) there is S-T segment depression suggesting myocardial ischemia.
exercise duration of 3.8 minutes. At this low work load, corresponding to approximately 63 percent of the predicted maximal heart rate for the mean age of the group, 13 patients (26 percent) had an abnormal electrocardiographic response. Seven patients (five men and two women) (14 percent) manifested S-T segment depression suggestive of myocardial ischemia7 and six patients (four men and two women) (12 percent) manifested frequent premature ventricular complexes (Fig. 1 and 2). “Frequent” was defined as a rate of occurrence exceeding one premature complex per four sinus complexes. To ascertain whether peripheral vascular laboratories utilizing treadmill exercise protocols routinely monitor the electrocardiogram during testing, we forwarded a questionnaire to 60 institutions. Of 34 centers responding to the inquiry, only 10 (29 percent) were recording the electrocardiograms of patients being evaluated with exercise testing. Discussion
The contraindications for submaximal treadmill stress testing in patients with suspected coronary artery disease have been fairly well agreed on, and only some of them can be recognized by means of a resting 12 lead electrocardiogram. Furthermore, in many instances termination of the test is based solely on the electrocardiographic response to exercise.7 The vast majority of subjects undergoing noninvasive evaluation of peripheral arterial circulation are not stressed to levels that approximate those utilized in submaximal exercise stress tests for assessing myocardial ischemia. Clinical implications of data: Our data indicate that a substantial number of patients referred to laboratories investigating the peripheral arterial circulation may have abnormal responses to mild degrees of exercise. These findings have both diagnostic and therapeutic implications. Application of continuous electrocardiographic recording during such testing would appear to be useful in identifying a number of patients with concomitant ischemic heart disease. The achievement of an average heart rate of only 106 beats/min suggests that these older patients with suspected or confirmed peripheral arterial disease may have a low ischemic threshold. Alternatively, such a
FIGURE 2. Control electrocardiogram (LII) from a 68 year old man with occlusive peripheral arterial disease and no history of angina pectoris or myocardial infarction. The tracing obtained at rest shows S-T segment and T wave abnormalities with occasional premature ventricular complexes. At 1 minute of exercise (1.7 miles/hour, 10 percent grade) salvos of extrasystoles are noted. One minute after termination of the test, ventricular bigeminy and paired premature complexes are recorded. Five minutes after exercise there were only two premature ventricular complexes/min.
heart rate may connote a fair degree of activity in a study group of patients who, because of their peripheral vascular disease, do not achieve an average exercise range in their daily activities. The S-T segment depression and the development of ventricular ectopy in 26 percent of the study group provide strong evidence that electrocardiographic monitoring should be performed in all subjects referred for exercise evaluation of the peripheral arterial system. Although none of the 50 patients had a cardiac arrest or sustained chest pain as a consequence of exercise, the potential for such events is clear. Patient safety would appear to be a major byproduct of exercise electrocardiographic monitoring in this group. Clinical application: Less than one third of responding peripheral vascular laboratories indicated that elect,rocardiographic monitoring was routinely applied in patients referred for the diagnosis of peripheral vascular disease. Universal application of such monitoring would provide a fruitful area for research into the coexistence of ischemic heart disease and occlusive peripheral arterial disease. Additionally, our data imply that resuscitative equipment and staff members well versed in the management of acute cardiac emergencies should be used at such centers. Concomitant electrocardiographic monitoring is used primarily for safety rather than for diagnostic purposes in these patients with suspected peripheral vascular disease. It should be appreciated by those working in peripheral vascular disease laboratories that associated coronary atherosclerotic heart disease may provide the limiting factor in the exercise testing even though the patients manifest no symptoms of lower limb disease during exercise. Furthermore, the electrocardiographic changes described here are only suggestive rather than specifically diagnostic of myocardial ischemia. Acknowledgment
We gratefully acknowledge the technical assistance of Kathy Tustison, Carole Crevier, Sydney Peebles, Betty Kjellberg and Saundra Morgan.
April 1979
The American Journal of CARDIOLOGY
Volume 43
715
EXERCISE ELECTROCARDIOGRAMIN PERIPHERAL ARTERIAL DISEASE-SILVESTRE ET AL.
References Spittell JA Jr, DeWolfe V, Hume M, Wlnsor 1, Wylie EJ: Prevention and early detection of peripheral vascular disease. Sub-committee on peripheral vascutar disease. Report of Inter-Society Commission for Heart Disease Resources. Circulation 42:A-43-A-45, 1970 (revised August 1972) Juergens JL, Barker NW, Hines EA Jr: Arteriosclerosis obliterans: review of 520 cases with special reference to pathogenic and prognostic factors. Circulation 21:188-195, 1960 Kannel WE, Sklnner JJ Jr, Schwartz MJ, Shurtleff D: Intermittent claudication. Incidence in the Framingham study. Circulation 41: 875-883. 1970
716
April 1979
The American Journal of CARDIOLOGY
4. Kannel WE, Shurtleff D: The natural history of arteriosclerosis obliterans. Cardiovasc Clin 3:38-52, 197 1 5. Tomeils LA, Flerens EE, Verbrugge GP: Evaluation of surgical risk in peripheral vascular disease by coronary arteriography: a series of 100 cases. Surgery 71:429-435, 1972 6. Lukaslk E, Llszewska-Pfejfer D: Obliterative arteriosclerosis of extremities in patients with coronary heart disease. Cor Vasa 19: 176-183, 1977 7. Ellestad MH: Stress Testing. Philadelphia, FA Davis, 1975, p 15, 16, 100
Volume 43
