Persistence
of Arrhythmia Exercise Response in Healthy Young Men
Yaacov Drory, MD, Amos Pines, MD, Enrique Z. Fisman, MD, and Jan J. Kellermann, MD
This study assesses the persistence of arrhythmia at rest or during exercise tests, or both, after a mean follow-up period of 6.7 years in 76 young men (mean age 21.5 years) without evidence of organic heart disease. The exercise test was performed using a near-maximal protocol based on progressively increasing intermittent work loads, each of 5 minutes’ duration. The initial work load was 50 W. The electrocardiogram was continuously registered throughout all stages of the examination. Arrhythmia was defined as the occurrence of or 1 ventricular premature > 1 supraventricular beat at any stage of the examination. At the followup examination, the rate of persistence of arrhythmia did not differ significantly among the subgroups, irrespective of follow-up interval, type of arrhythmia, or arrhythmia patterns of response to exercise. Two-dimensional echocardiography did not show any structural abnormalities and Doppler examination did not demonstrate significant abnormal flow patterns. Our data show that almost all patients continued to present arrhythmia after the follow-up period, without any evidence of development of organic heart disease. Moreover, the arrhythmia pattern of response to exercise remained constant throughout the years. At this time, arrhythmia without underlying heart disease seems to be of a benign natural course in these young men. (Am J Cardiol 1990;66:1092-1094)
From the Cardiac Rehabilitation Institute, Chaim Sheba Medical Center, Tel Hashomer, Israel, the Department of Internal Medicine “I”, Ichilov Hospital, Tel Aviv, Israel, and the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. This study was supported by a grant from the late Yona Ettinger, New York, New York. Manuscript received March 3,199O; revised manuscript received and accepted June 18, 1990. Address for reprints: Yaacov Drory, MD, Cardiac Rehabilitation Institute, Chaim Sheba Medical Center, Tel Hashomer, 52621 Israel.
1092
THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 66
I
t is generally agreed that arrhythmias occurring in the absenceof structural heart diseaseare mostly of a benign nature.1-5However, the nature and consequencesof arrhythmia in healthy young adults warrant further inquiry in view of reports of sudden death and clinical deterioration in rare cases.6Long-term followup studies on healthy young people with arrhythmias6-8 are few; there is only a limited number on the use of exercise testing in the long-term evaluation of arrhythmias,9 and scarcely any data on exercise-inducedarrhythmia and its reproducibility and presenceat longterm follow-up examination in this population.lO,ll This paucity of information on the persistenceof arrhythmia in healthy people prompted us to reexamine young men with arrhythmia at rest, during exercise tests, or both, at long-term follow-up. METHODS Study group: The study group comprised 76 men,
mean age 21.5 years (range 15 to 29) with arrhythmia at rest, or during exercisetests,or both, on initial examination. These patients were referred to our institute for evaluation of arrhythmias found during routine medical examinations. All patients were free of known cardiovascular diseaseand did not present risk factors for the development of premature coronary disease.Physical examination, routine laboratory tests and chest roentgenogramswere normal. The patients were reexamined at irregular intervals 3 to 16 (mean 6.7) years later. During the follow-up period, intermediate additional examinations were conducted in 29 patients (1 additional examination in 21 patients, 2 in 7, and 6 in 1). On initial examination, 38 (50%) patients reported symptoms attributable to arrhythmia, such as palpitations (36), dizziness (27), syncope(15). At follow-up, 25 (33%) patients reported palpitations or dizziness. However, arrhythmias detected during the exercisetest were not associated with these symptoms. None received antiarrhythmic medication, neither on initial examination nor during the follow-up period. Detailed individual case histories were recorded; each patient underwent a thorough physical examination, resting 1Zlead electrocardiography, chest roentgenography,a cycloergometrictest, and 2-dimensional and Doppler echocardiography. Exercise test: The ergometric test was performed on a mechanically braked Monark bicycle ergometer, following our previously described protocol.12All patients underwent a near-maximal test (85% of predicted maximal heart rate according to age) basedon progressively increasing intermittent work loads, each of 5 minutes’ duration. The initial work load was 50 W. Blood pres-
s of Arrhythmia
Diagnosed
Persistence
solated ventricular
premature
beats
Nonsustained ventricular tachycardia Sustained ventricular tachycardia Supraventricular
ts of supraventricular
Types of arrhythmia
on
tachycardia response to exercis
Aients;
*Ventricular couplets in 3 patie 5 Bouts of supraventncular ta premature beats in 17.
tricular
>lOO%
increase
premature pa&n%; wlated
in frequency
beats I” 11. supraventrlcular
plex ventricular arrhythmia was found in 10% of patients. Arrhythmia patterns of responseto the exercisetests are listed in Table II. We observedboth the appearance and augmentation of either supraventricular or ventricular arrhythmia in more than one-third of patients, and its disappearancein 41% of patients with ventricular, as well as in 48% of patients with supraventricular arrhythmias. There was no demonstrable effect of exercise on arrhythmia in the rest of the group. The patterns of response to exercise were similar in both types of arrhythmia. Follow-up examination: Arrhythmia at rest, or during exercise tests, or both, was demonstrated in 60% of 76 patients at follow-up examination (Table III). The rate of occurrence of arrhythmia in the patient group with the longer duration of follow-up (6 to 16 years) was not significantly different from that in the group whose follow-up interval was 3 to 6 years. The rate of persistenceat follow-up examination did not differ significantly for patients with either ventricular or supraventricular arrhythmia, or for those who had had different arrhythmia patterns of responseto exercise on the initial examination. Furthermore, the patterns of responsein almost all (98%) patients with arrhythmia at follow-up showed no change from the initial findings. Two-dimensional echocardiographic examination did not show any structural abnormalities; cavity dimensions, wall thicknesses and valvular ftinc‘tion were normal in all patients. Contractility was normal as well. Doppler examination did not demonstrate significant abnormal flow patterns.
sure was measured at rest, in the supine and upright positions, as well as at the precise end of each work load and during the recovery period. Patients were instructed not to eat or smoke and to avoid drinking coffee or tea for 4 hours before the examination. All patients were informed that the exercisetest was a routine procedure. The electrocardiogram was continuously registered throughout all stagesof the examination, and heart rate was assessedby the electrocardiographic tracings. Arrhythmia: Arrhythmia was defined as the occurrence of 21 supraventricular premature beat or 1 ventricular premature beat at any stage of the examination. Conduction disturbances, respiratory arrhythmia and multifocal supraventricular rhythm (wandering pacemaker) were not regarded as rhythm disturbances. Augmentation of arrhythmia at exercisetest was defined as 2100% increase in the frequency of premature beats, or the occurrence of multiform or repetitive forms. Decreaseof arrhythmia at exercise was defined ISCUSSION as 175% reduction in frequency. Of our 76 healthy young men with arrhythmia at Statistical analysis: All results are expressedas percentages.Chi-square tests were used to examine differ- rest, or during exercisetests,or both, on initial examinaencesbetween groups; p values
of Arrhythmia Exercise Response in Healthy Young Men
Yaacov Drory, MD, Amos Pines, MD, Enrique Z. Fisman, MD, and Jan J. Kellermann, MD
This study assesses the persistence of arrhythmia at rest or during exercise tests, or both, after a mean follow-up period of 6.7 years in 76 young men (mean age 21.5 years) without evidence of organic heart disease. The exercise test was performed using a near-maximal protocol based on progressively increasing intermittent work loads, each of 5 minutes’ duration. The initial work load was 50 W. The electrocardiogram was continuously registered throughout all stages of the examination. Arrhythmia was defined as the occurrence of or 1 ventricular premature > 1 supraventricular beat at any stage of the examination. At the followup examination, the rate of persistence of arrhythmia did not differ significantly among the subgroups, irrespective of follow-up interval, type of arrhythmia, or arrhythmia patterns of response to exercise. Two-dimensional echocardiography did not show any structural abnormalities and Doppler examination did not demonstrate significant abnormal flow patterns. Our data show that almost all patients continued to present arrhythmia after the follow-up period, without any evidence of development of organic heart disease. Moreover, the arrhythmia pattern of response to exercise remained constant throughout the years. At this time, arrhythmia without underlying heart disease seems to be of a benign natural course in these young men. (Am J Cardiol 1990;66:1092-1094)
From the Cardiac Rehabilitation Institute, Chaim Sheba Medical Center, Tel Hashomer, Israel, the Department of Internal Medicine “I”, Ichilov Hospital, Tel Aviv, Israel, and the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. This study was supported by a grant from the late Yona Ettinger, New York, New York. Manuscript received March 3,199O; revised manuscript received and accepted June 18, 1990. Address for reprints: Yaacov Drory, MD, Cardiac Rehabilitation Institute, Chaim Sheba Medical Center, Tel Hashomer, 52621 Israel.
1092
THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 66
I
t is generally agreed that arrhythmias occurring in the absenceof structural heart diseaseare mostly of a benign nature.1-5However, the nature and consequencesof arrhythmia in healthy young adults warrant further inquiry in view of reports of sudden death and clinical deterioration in rare cases.6Long-term followup studies on healthy young people with arrhythmias6-8 are few; there is only a limited number on the use of exercise testing in the long-term evaluation of arrhythmias,9 and scarcely any data on exercise-inducedarrhythmia and its reproducibility and presenceat longterm follow-up examination in this population.lO,ll This paucity of information on the persistenceof arrhythmia in healthy people prompted us to reexamine young men with arrhythmia at rest, during exercise tests, or both, at long-term follow-up. METHODS Study group: The study group comprised 76 men,
mean age 21.5 years (range 15 to 29) with arrhythmia at rest, or during exercisetests,or both, on initial examination. These patients were referred to our institute for evaluation of arrhythmias found during routine medical examinations. All patients were free of known cardiovascular diseaseand did not present risk factors for the development of premature coronary disease.Physical examination, routine laboratory tests and chest roentgenogramswere normal. The patients were reexamined at irregular intervals 3 to 16 (mean 6.7) years later. During the follow-up period, intermediate additional examinations were conducted in 29 patients (1 additional examination in 21 patients, 2 in 7, and 6 in 1). On initial examination, 38 (50%) patients reported symptoms attributable to arrhythmia, such as palpitations (36), dizziness (27), syncope(15). At follow-up, 25 (33%) patients reported palpitations or dizziness. However, arrhythmias detected during the exercisetest were not associated with these symptoms. None received antiarrhythmic medication, neither on initial examination nor during the follow-up period. Detailed individual case histories were recorded; each patient underwent a thorough physical examination, resting 1Zlead electrocardiography, chest roentgenography,a cycloergometrictest, and 2-dimensional and Doppler echocardiography. Exercise test: The ergometric test was performed on a mechanically braked Monark bicycle ergometer, following our previously described protocol.12All patients underwent a near-maximal test (85% of predicted maximal heart rate according to age) basedon progressively increasing intermittent work loads, each of 5 minutes’ duration. The initial work load was 50 W. Blood pres-
s of Arrhythmia
Diagnosed
Persistence
solated ventricular
premature
beats
Nonsustained ventricular tachycardia Sustained ventricular tachycardia Supraventricular
ts of supraventricular
Types of arrhythmia
on
tachycardia response to exercis
Aients;
*Ventricular couplets in 3 patie 5 Bouts of supraventncular ta premature beats in 17.
tricular
>lOO%
increase
premature pa&n%; wlated
in frequency
beats I” 11. supraventrlcular
plex ventricular arrhythmia was found in 10% of patients. Arrhythmia patterns of responseto the exercisetests are listed in Table II. We observedboth the appearance and augmentation of either supraventricular or ventricular arrhythmia in more than one-third of patients, and its disappearancein 41% of patients with ventricular, as well as in 48% of patients with supraventricular arrhythmias. There was no demonstrable effect of exercise on arrhythmia in the rest of the group. The patterns of response to exercise were similar in both types of arrhythmia. Follow-up examination: Arrhythmia at rest, or during exercise tests, or both, was demonstrated in 60% of 76 patients at follow-up examination (Table III). The rate of occurrence of arrhythmia in the patient group with the longer duration of follow-up (6 to 16 years) was not significantly different from that in the group whose follow-up interval was 3 to 6 years. The rate of persistenceat follow-up examination did not differ significantly for patients with either ventricular or supraventricular arrhythmia, or for those who had had different arrhythmia patterns of responseto exercise on the initial examination. Furthermore, the patterns of responsein almost all (98%) patients with arrhythmia at follow-up showed no change from the initial findings. Two-dimensional echocardiographic examination did not show any structural abnormalities; cavity dimensions, wall thicknesses and valvular ftinc‘tion were normal in all patients. Contractility was normal as well. Doppler examination did not demonstrate significant abnormal flow patterns.
sure was measured at rest, in the supine and upright positions, as well as at the precise end of each work load and during the recovery period. Patients were instructed not to eat or smoke and to avoid drinking coffee or tea for 4 hours before the examination. All patients were informed that the exercisetest was a routine procedure. The electrocardiogram was continuously registered throughout all stagesof the examination, and heart rate was assessedby the electrocardiographic tracings. Arrhythmia: Arrhythmia was defined as the occurrence of 21 supraventricular premature beat or 1 ventricular premature beat at any stage of the examination. Conduction disturbances, respiratory arrhythmia and multifocal supraventricular rhythm (wandering pacemaker) were not regarded as rhythm disturbances. Augmentation of arrhythmia at exercisetest was defined as 2100% increase in the frequency of premature beats, or the occurrence of multiform or repetitive forms. Decreaseof arrhythmia at exercise was defined ISCUSSION as 175% reduction in frequency. Of our 76 healthy young men with arrhythmia at Statistical analysis: All results are expressedas percentages.Chi-square tests were used to examine differ- rest, or during exercisetests,or both, on initial examinaencesbetween groups; p values
