The 24-Hour Holter ECG Monitoring in Normal Population

ABSTRACT

Holter ECG monitoring is a continuous tape recording of a patient's electrocardiogram during ordinary activities and picks up hidden abnormalities in rate, rhythm or conduction. The authors delineated the types and incidence rates of arrhythmia in 32 normal Koreans by utilizing medical personnels and patients without evident heart diseases or symptoms, or significant systemic illness. Tracings and analysis were performed using 24 hour Holter monitoring processor(SCM 240, Fukuda, japan), auto-analyser (SCM-25), casette recorder(SM 24) and chrome tape. Results are as follows: 1) Portable 24 houre Holter ECG monitoring was performed in 32 persons(age range of 21 to 35) without cardiovascular disease, as defined by normal clinical and noninvasive cardiovascular examination. 2) During exercise, maximal heart rates ranged from 125.0+/-12.1/min and minimal rates from 96.7+/-5.8/min. During normal activity period, maximal and minimal heart rates were, respectively, 95.4+/-16.2/min and 62.6+/-6.3/min. Maximal sleep rates were 90.3+/-26.6/min and minimal sleep rates 57.4+/-12.4/min. 3) P-R interval decreased as heart rate increased. Transient first degree AV block was noted in 3 subjects(9.4%) and Wenckebach type second degree AV block in 2 subjects(6.3%). 4) Sinus tachycardia and bradycardia were observed in all subjects and sinus arrhythmia was more frequently noted during waking periods. Three subjects had episodes of sinus pause with maximum duration of 3.24 seconds. 5) In 13 persons(40.6%) having supraventricular premature beats, the frequency was 50.01+/-49.36/hr and in 14 persons having(44%) ventricular premature beats the frequency 26.33+/-18.83/hr. Transient ventricular tachycardia of 3 seconds' duration was observed in one subject under the extreme stressful environment. 6) ST segment elevation over 1mm was noted in 5 subjects(15.6%), of whom one had a nocturnal chest pain and ST segment depression over 1mm in 2 subjects. T wave inversion was also found during exercise(3.1%) and during sleep(9.4%).