24 hour circadian pattern of blood pressure and its related target organ damage in hypertensive subjects / 대한내과학회지

OBJECTIVE: Pattern with essential hypertension generally shows the same circadian pattern as the normothensive person with a night-time reduction or "DIP" in blood pressure in sleep. The definition of "Dipper" and "Non-dipper" are assigned according to arbitrary criteria e.g. a night time average blood pressure which is at least 10% less than the average daytime blood pressure. Prospective evidence that the absence of an overnight dip is a strong adverse prognostic indicator for target organ damage .Thus we investigate circardian rhythm of blood pressure, related target organ damage, its frequency & drug in hypertensive subjects. Method : 24hr ambulatory blood pressure monitoring, history taking, physical examination, fundoscopy, ECG, chest X ray, dipstick urinanlysis, serum creatinine level are performed in essential hypertensive subjects. Exclusion criteria are duration of hypertension over 5 years, DM, renovascular hypertension & heart failure. RESULTS: Total 42 patients performed study.17 subjects classify dipper group,25 subjects classify non-dipper group. Between dipper & non-dipper group shows no significantly difference at stroke history, C/T ratio over 0.5 in chest X-ray, left ventrcular hypertrophy in ECG,ST-T change in ECG, proteinuria & serum creatinine level. Non-dipper group shows significantly difference to dipper group in frequency of hypertensive retinopathy and number of combined drug used subjects. CONCLUSION: Number of hypertensive retinopathy is significantly frequency in non-dipper group. Hypertensive retinopathy is atherosclerotic complication, thus we predict other target organ damage, therefore non-dipper type circardian rhythm of blood pressure is adverse prognostic factor for target organ damage of hypertensive subjects.

Signal Averaged Electrocardiography Using Holter Tape in Patients without Heart Disease

BACKGROUND: Ventrlcular tachyarrhythmias are major cause of sudden cardiac death in patients after myocardial infarction and their accurate detection seems to be important in prevention of sudden cardiac death. Clinical findings, treasmill test, holter monitoring and coronary angiography have been used to search for high risk group in sudden cardiac death. Recently electrographysiologic stimulation has been to this, but it is not practical, because of high cost and invasiveness. Signal averaged electrocardiogram(SAECG) may be helpful in prediction of high risk group in sudden cardiac death. So we try to know the values of SAECG in Korean patients without heart disease. RESULTS: 1) The mean value and standard deviation of Time domain analysis is as follows ; fQRS : 106.8+/-12.3ms, RMS : 36.2+/-21.5(micro)V, LAS : 27.2+/-8.1ms. 2) The mean value and standard deviation of Spectral turbulence analysis is a follows ; LSCR : 58.6+/-3.9, ISCM : 95.2+/-0.8, ISCSD : 71.8+/-15.7, SE : 6.9+/-1.8. CONCLUSION: There was no significant difference between male and female. Time domain analysis shows significant differences among each hour but spectral turbulence analysis did not. Spectral turbulence analysis shows high specificity.

Comparative Study of Signal-Averaged Electrocardiogram between Time Domain Analysis and Spectral Turbulence Analysis by 24-hr Holter Monitoring / 대한내과학회지

OBJECTIVES: Signal-averaged electrocardiography (SAECG) has been found to be a useful noninvasive technique for identifying patients at risk for life-threatening ventricular tachycardia. Delayed and fragmented activation of abnormal myocardial tissues causes the occurrence of high frequency low amplitude (HFLA) electocardiographic signals or late potentials. Generally, there are two methods in analyzing signal-averaged electrocardiography. Late potentials in the time domain analysis do not provide sufficient diagnostic power with regard to life-threatening Ventricular tachycardia. Buckingham et al. (1989) reported a time-domain sensitivity of 62%, a specificity of 75%. Spectral turbulence analysis (STA) of the signal-averaged ECG is the most recent frequency domain technique to improve the time domain sensitivity and specificity. So, We designed the study to compare the efficacy of Time Domain Analysis and Spectral Turbulence Analysis among five groups (Normal control, QRS widening, Postmyocardial infarction, Frequent VPC's with group beats, Nonsustained ventricular tachycardia). METHODS: 88 patients were selected from the patients who had been admitted between January 1994 and October l994, at National Medical Center. Patients were divided into five groups, which were respectively, Group A: Normal control group (n=33), Group B: QRS widening group (n=14), Group C: Postmyocardial infarction group (n=10), Group D: Frequent VPC's with group beats (n=22), Group E: Nonsustained VT group (n=9). We compared Spectral Turbulence Analysis and Time Domain Analysis of Signal-Averaged Electrocardiogram by 24 hours-Holter monitoring. RESULTS: 1) In normal control group(Group A), 9.1%(3 patients) were positive by Time Domain Analysis, but, all were negative by Spectral Turbulence Analysis. 2) In QRS widening group (Group B), 71.4%(10 patients) were positive by Time Domain Analysis, but, all were negative by Spectral Turbulence Analysis. 3) In postmyocardial infarction group (Group C), 309o were positive by Time Domain Analysis, and 10% were positive by Spectral Turbulence Analysis. 4) In frequent VPC's group (Group D), 22.7% (5 patients) were positive by Time Domain Analysis, and, 4.5%(1 patient) was positive by Spectral Tur-bulence Analysis. 5) In Nonsustained VT group (Group E), 33.3% (3 patients) were positive by Time Domain Analysis, and 11.1% (1 patient) was positive by Spectral Turbulence Analysis. CONCLUSIONS: In Time Domain Analysis, abnormal results were presented at Group R (QRS widening group) by 71.4%, which was markedly higher than other groups. But, in Spectral Turbulence Analysis, abnormal results were not presented at Group A and Group B. In Group A and Group B, Spectral Turbulence Analysis shows less false positive results than Time Domain Analysis.

The Transition of Internal Diseases of the aged in Korea

BACKGROUND: Recent times, elderly population increased due to development of medical treatment and extension of the average span of a human life. Hereupon, variable studies and measures for elderly population were made an attempt in the world at large. In medical treatment, an aged person related an institutes begin to vivacious activity for reflection of this national concern. So we survey the transition of internal diseases of the aged in Korea for 10 years lo support the policy of medical treatment. METHODS: In order to access this study, we use data of korea medical insurance coorporation and national statistical office republic of Korea. We classified internal diseases into several diseases by age, and sex. RESULTS: 1. The transition of out-Patients Digestive troubles have the most high prevalence in both men and women, and cardiovascular diseases are become increasing. Endocrine diseases are become increasing also. 2. The transition of in-patients 1) 65-69 years old Neoplastic diseases and digestive diseases are high in men, but cardiovascular disease are become increasing. Digestive diseases are high in women but, cardiovascular disease and endocrine diseases are become increasing. 2) 70-74 years old Cardiovascular diseases are decreased in men and especially in women. 3) Over 75 years old Digestive diseases are decreased in both men and women, endocrine diseases and cardiovascular diseases are increased in women. 3. The transition of the cause of death. The cardiovascular diseases are high in both men and women, and showed decreasing tendency gradually, Neoplastic diseases and endocrine diseases are increasing in steady. CONCLUSION: In our data, the cardiovascular diseases are high especially, in women according to age in the transition of internal diseases of an aged man in Korea, recent 10 years and endocrine diseases are increasing in steady. So, in medical treatment, we must consider many-sided methods to access this population

Assessment of Autonomic Disturbance by 24-hour Heart Rate Variability in Patients with Liver Cirrhosis / 대한내과학회지

OBJECTIVE: Heart rate variability(HRV) is helpful to diagnosis autonomic disturbance and sympathetic-parasympathetic imbalance in patients with myocardial infarction and diabetes mellitus. Patients with liver cirrhosis demonstrate reduced blood pressure despite increased heart rate and increased cardiac output, indicating a fall in peripheral vascular resistance. Autonomic disturbance may contribute to this phenomenon. The aim of the present study is to evaluate the degree of autonomic disturbance and the circadian rhythm of autonomic nervous system by estimating HRV with 24 hour-Holter recorder, METHODS: 24 hour-HRV with Del Mar Avionics 563 Holter recorder and cardiovascular reflex tests were carried out on 32 patients with liver cirrhosis and 20 control subjects. We evaluated the presence of autonomic disturbance, and assessed quantitatively the autonomic disturbance. RESULTS: 1) Among cardiovascular reflex tests, Valsalva test, standing test and deep breathing test were showed a significantly decreased response in liver cirrhosis compared with control groups. 2) The standard deviation of 24hours average R-R intervals were showed a significantly decrease in liver cirrhosis than control groups(P<0.0001). The HRV of low frequency(LF. P<.D.001), high frequency(HF, P<0.0001) and total power spectral density (P<0.0001) in liver cirrhosis were statistically lower than control. 3) The LF/HF ratio of patients with liver cirrhosis was showed higher than control at night CONCLUSION: Non-invasive assessment of 24 hour-HRV has a few advantages in the diagnosis and degree of autonomic disturbance, evaluation of diurnal variation of autonomic tone.

Circadian Variation of Cardiac Autonomic Function in Hypertensives

BACKGROUND: We addressed the problem of the circadian changes in neural control of the circulation in ambulant hypertensive subjects. With spectral analysis of heart rate variability the tonic sympathetic and vagal activities and their changes are respectively assessed by the power of 0.050 - 0.015Hz(low frequency, LF) and 0.150 - 0.350Hz(respiratory linked, high frequency, HF) components of the spectrum of the beat by beat variability of RR interval. METHODS: Heart rate variability(HRV) and its circadian rhythm were evaluated in 15 patients with hypertension. By using 24-h Holter monitoring, HRV and its spectral components were measured. Finding were compared with 15 age-matched normal controls. RESULTS: The 24-hour plot of the SDs revealed that heart rate variability was significantly lower in the hypertensive patients, and the differences reached statistical significance during hours 2, 3, 9, 13, 16, 18, 19, and 23(p<0.05). Spectral analysis showed that power in the high-frequency range(0.150 to 0.350Hz) was lower among the hypertensive patients than among the normal controls during 22 of 24 hours but that the difference was statistically significant only during 2 hours(p<0.05). Power in the low frequency range(0.050 to 0.150Hz) was low at night, increased in the morning, and high during the day among controls ; this circadian rhythm was absent among hypertensive patients. CONCLUSIONS: Among hypertensive patients, HRV is decreased with a partial withdrawal of parasympathetic tone, and the circadian rhythm of sympathetic/parasympathetic tone is altered.

24 Hours Heart Rate Variability in Elderly Hypertensive Patients

BACKGROUND: Heart Rate Variability help us to diagnose the impairment of autonomic nervous system in patients with diabetes, hypertension, ischemic heart disease, chronic renal disease, and arrhythmia. Change of autonomic nervous system is related to circadian rhythm, stress, physical activity, and so on. Especially, impairment of vagal nervous system with age help us to expect sudden cardiac death, myocardial infarction, and arrhythmia. So we survey heart rate variability by using 24 hours holter monitoring to expect impairment of autonomic nervous system in elderly hypertensive patients. METHODS: In order to assess 24 hours heart rate variability, we use Del Mar Avionics 563 holter monitoring on 11 elderly hypertensive patients( > or =65 years), 12 younger hypertensive patients( <65 years), and 15 normal subjects. RESULTS: 1) Standard deviation of mean R-R interval, LF(low frequency), HF(high frequency), TPSD(total power spectral density) are more decreased in elderly hypertensive patients than in younger hypertensive patients in 24 hours health rate variability analysis(t-test p<0.05). 2) According to age, elderly control group had lower LF power spectral parameter than younger control group had, but other parameters were not decreased, and elderly hypertensive group had lower LF, HF, TPSD, SD of mean R-R interval than younger hypertensive group did(p<0.05). 3) In circardian rhythm, normal subjects had high HF power spectral parameter and low LF power spectral parameter at evening and night. On the other hand, elderly hypertensive group had constant low level of LF, HF power spectral parameter during the day and night. CONCLUSIONS: On heart rate variability analysis using by 24 hours Holter monitoring, heart rate variability was decreased, and impairment of autonomic nervous system was accelerated in elderly hypertensive patients.

Comparison between Myocardial Infarction and Congestive Heart Failure Using by Heart Rate Variability Analysis of 24 hours Holter Monitoring

OBJECTIVES: Power spectrum analysis decomposes the heart rate signal into its frequency components and facilitates separation of sympathetic (low frequency) and parasympathetic (high frequency) activity. In congestive heart failure, augmented sympathetic tone and decreased parasympathetic tone were found. Autonomic nervous system was normalized 6 months after myocardial infarction. So we compared the autonomic nervous system activity by the heart rate variability in congestive heart failure and old myocardial infarction. METHODS: The protocol involved 20 healthy subjects (Group 1), 5 congestive heart failure patients not caused by myocardial infarction (Group 2), 4 congestive heart failure patients due to myocardial infarction and 11 old myocardial infarction patients without heart failure. We took 24 hour Holter monitoring by Del Mar Avionic tape recorder. All Holter tapes were analyzed with use of Model 563 Stratascan Holter Analysis System. We computed power spectra on each 256 sec segment of each hour during 24 hour recording. So, RR interval, SD of RR interval by time domain, and LF, HF, LF/HF ratio, Total PSD by frequency domain were measured. RESULTS: In congestive heart failure, nocturnal HF peak and diurnal variation of LF/HF ratio was decreased relative to healthy subjects. Nocturnal HF peak in old myocardial infarction was not visualized. All of LF, HF and Total PSD in congestive heart failure and old myocardial infarction patients relative to healthy subjects. CONCLUSION: On heart rate variability analysis using by 24 hour Holter monitoring, abnormal autonomic nervous activity was demonstrated in congestive heart failure and old myocardial infarction patients relative to healthy subjects.

Diagnostic Significance of Pseudonormalization during Treadmill Exercise Test in Ischemic Heart Disease

BACKGROUND: The interpretation of electrocardiographic change in treadmill exercise test is difficult when the test is performed in patients with abnormal resting electrocardiography. In patients with primary nagative T wave, normalization of primary negative T wave(pseudonormalization)is not uncommon finding during treadmill exercise test. The mechanism of pseudonormalization is uncertain and the interpretation is difficult. Thus this study was performed to evaluate the diagnostic significance of pseudonormalization during treadmill exercise test. METHODS: 200 cases who showed primary negative T wave at rest were included in this study. The results were classified as positive, borderline positive, borderline negative, negative, non-diagnostic and pseudonormalization. RESULTS: Pseudonormalization during treadmill exercise test was oberved in 78(39%) of the 200 cases who had primary negative T wave at rest. Coronary angiography and left ventriculography were performed in 13(mean age 56+/-7 year, male vs. female 1:2.25) of 78 cases who showed pseudonormalization during exercise. They had no history of acute myocardial infarction and no abnormalities such as abnormal Q wave, left ventricular hypertrophy,bundle branch block,right ventricular hypertrophy and QRS widening above 0.1ms in resting electrocardiography. There were significant stenosis in only 3 cases; 2 cases in left anterior descending coronary artery and 1 case in right coronary artery. CONCLUSION: In treadmill exercise tests, pseudonormalization appears as non-specific finding for the diagnosis of ischemic heart disease becuase it is observed in either patients with or without coronary artery stenosis.

Clinical Study of Risk Factors in Patients with Acute Myocardial Infarction

BACKGROUND: The major risk factors such as hypercholesterolemia, hypertension, diabetes melitus and cigarrete smoking have not been studied in an attempt to provide a composition of major risk factors in Korea. Also we have met with some patients without major risk factors. METHODS: A Retrospective Study was done on 160 patients of acute myocardial infarction who had been admitted to National Medical Center within 48 hours from onset, from January 1948 to December 1992 and studied on major risk factors of acute myocardial infarction. RESULTS: 1) Among major risk factors, smoking was found in 50%, hypertension in 49%, diabetes in 25% and hypercholesterolemia in 21%. 2) The percentage of patients without major risk factors was 19%. 3) Among major risk factors, hypertension, hypercholesterolemia and diabetes were increasing tendencies, recentely. CONCLUSION: Some patients with acute myocardial infarction don't have any major risk factors. Also hypertension, hypercholesterolemia and diabetes were increasing tendencies. So further study for other risk factors is needed and preventive management should require a commitment to behavior modification and alteration in life-style.

The Effect of Non-Ionic Contrast Media on Q-T Interval and ST-T Wave of ECG during Coronary Angiography

BACKGROUND: During coronary angiography, some electrocardiographic changes occured due to contrast media, which do life threatening influences. METHODS: We compared the electrocardiographic changes which were induced by injection of three radiopaque contrast media during selective coronary angiography in 49 patients with chest pain. One of the contrast media was high osmolar ionic(Urografin_76) and the another was low osmolar ionic(Hexabrix) and the last was non-ionic(Ioversol). Electrocardiograms were obtained before, during and after selective coronary angiography. RESULTS: The changes of S-T segment or T were decreased in non-ionic group rather than high osmolar or ionic group. And there was significant Q-Tc interval prolongation among all three groups except comparision of low osmolar ionic contrast dye and non-ionic contrast dye in left coronary angiography. CONCLUSION: Non-ionic low osmolar contrast media was safer than high osmolar or ionic contrast medial because of lesser change of Q-Tc interval during selective coronary angiography.

The study of 24-hour holter monitoring in patients with coronary artery disease

BACKGROUND: Patients with ischemic heart disease have many episodes of ischemic attack which is presented as ST-T change in electrocardiogram during ordinary daily life. The purpose of this study was to confirm the presence of a significant circardian variation in transient myocardial ischemia and the difference of the incidence of ischemia according to involved vessel. METHODS: Twenty two patients with angiographically significant coronary stenosis were evaluated. The ambulatory electrocardiography(Holter monitoring) was performed in each patients. RESULTS: One hundred twenty-eight episodes of ischemic ST-T changes occured in 18(82%) of 22 patients and 65(51%) episodes of ischemic ST-T changes occured between 6 A.M. and 12 noon(p<0.005). The mean frequency per patient according to involved vessel was 9 in double vessel disease, 4.5 in diffuse sclerosis with old myocardial infarction, 2.9 in single left anterior descending, 2.3 in single right coronary and 1 in single left main coronary artery disease. The only one episode of T wave change was observed in patients with lesion of left circumflex artery. The mean frequency of ST changes per patient according to type of angina was 4.8 in postinfartion angina, 3.5 in unstable angina and 2.1 in stable angina and the mean frequency of T change was 4.7 in stable angina, 2 in unstable angina and 0.3 in postinfarction angina. CONCLUSIONS: The significant circardian variation of ischemic activity was found in patients with ischemic heart disease. The mean frequency of ST change was higher in double vessel disease and diffuse sclerosis with old myocardial infarction than in other coronary artery lesion. And the episode of ST change was more frequent in postinfarction angina and unstable angina pectoris and the episodes of T change in stable angina pectoris. Also this study suggest 24-hour Holter monitoring has a low detectability of ischemic episodes in patient with lesion of left circumflex artery.

Complications for implanted cardiac permanent pacemaker / 대한내과학회지

No abstract available.

Differential Diagnosis between Dilated Cardiomyopathy and Ischemic Heart Failure with Post-Exercise Echocardiography

BACKGROUND: Ischemic cardiomyopathy and dilated cardiomyopathy may be clinically indistinguishable and cardiac catheterization is often required to differentiate between them. And many nonivasive methods including myocardial Thallium scan have showed nonspecific results in differentiating between them. METHODS: We studied the change of echocardiographic ejection fraction after exercise in 8 patients with ischemic heart failure and 9 patients with dilated cardiomyopathy and have assessed the usefulness of this noninvasive technique in distinguishing between the two groups. RESULTS: All patients with ischemic cardiomyopathy displayed the significant decrease of ejection fraction at 5 minutes after exercise(p28.75+/-7.89%-->34.38+/-8.50%). Respectively, all patients with dilated cardiomyopathy showed the significant increment of ejection fraction at 5 minutes(p46.33+/-11.93%-->35.00+/-5.68%). CONCLUSION: Our results suggest that echocardiographic ejection fraction at post-exercise 5 minutes, will be the adjunctive method to differentiate between ischemic cardiomyopathy and dilated cardiomyopathy.

Differential Diagnosis in Cases Showing Poor R-Wave Progression on EKG by Vectorcardiography

The vectorcardiography was performed on 34 cases with PRWP of precordial leads. We have studied the vectorcardiographic finding for the differential diagnosis of disease entities were obtrained; 1) Poor R-Wave progression of precordial leads has simply considered as suggestion of anterior myocardial infarction, ischemic heart disease, chronic lung disease and normal variant. 2) The sensitivity and specificity of myocardial infarction criteria were 85.8% and 63.0% respectively in left sagittal plane and 85.8% and 66.7% respectively in horizontal plane. 3) The seneitively and specificity of more than 90 QRS-T vector angle in left sagittal plane were 100.0% and 62.5% respectively in ischemic heart disease and myocardial infarction. 4) The sensitively and specificity of chronic lung disease criteria were 85.7% and 51.9% respectively. 5) Vectorcardiographic study was considered as effective differentiating method for patients with PRWP in EKG.

Clinical and Hemodynamic Observation on Constrictive Pericarditis

A clinical study was done on 16 cases of constrictive pericarditis admitted to National Medical Center, from january, 1970 to October, 1982, were reviewed, conclusion as follows: 1) The patients with constrictive pericarditis generally revealed clinical features of right heart failure but low incidence of its characteristic features. 2) Hemodynamic and echocardiographic examinations were much helpful in confirmation of clinical diagnosis. 3) pericardiectomy was highly succesful in achievement of clinical improvement.

Studies on Hemodynamic Assessment and Ventricular Performance in Patients with Mitral Valvular Disease

The cardiac performance is regulated by the intergration of preload, afterload, contractility (inotropism), heart rate and synergy of ventricular contraction, which are the major determinants that govern the stroke volume and cardiac output. Valvular heart disease may be considered to impose two different types of stress on the cardiac chamber proximal to the lesion. There are either pressure overload(increased after load) or volume overload(increased preload). The compensatory mechanism of the pressure overload and volume overload offer to hypertrophy and dilatation of the chamber. Hypertrophy, increased muscle mass, calls upon the development of greater systolic force. Dilatation, overfilled chamber volume enables increased strength and extent of shortening by Frank Starling's mechanism. In these view, we shall discuss the hemodynamic parameters; cardiac output, stroke volume, ventricular end-diastolic pressure, and the rate of ventricular pressure rise(peak dp/dt), mitral valve gradient and pulmonary circulation. The authors had an opportunity to study 40 cases of mitral valvular heart disease which were accepted during the left ventricular angiography at the cardiac catheterization room and at the fields of operative findings during the period Jan. 1977, throught Sept. 1980, at the Department of Internal Medicine, National Medical Center. The following conclusions were drawn: 1) Cardiac index was 2.65 L/min/m2in average, among 18 cases with mitral stenosis and 2.54 L/min/m2 in average, among 15 cases with mitral valve area of less than 1.0 cm2. Cardiac index was 2.58 L/min/m2in average, among 19 cases with mitral stenoinsufficiency and 3.43 L/min/m2 in average, among 3 cases with pure mitral insufficiency. 2) The mean right ventricular end-diastolic pressure elevated more than 0-8 mmHg were found in 12 cases with mitral stenosis out of 18 cases and mean miral valve area was 0.8m2. The mean left ventricular end-diastolic pressure was also elevated more than 0-12 mmHg in 6 cases out of 12 cases with mitral stenosis in addition to right ventricular failure. These 12 cases of mitral stenosis had cardiac function more than class III clinically. 3) 15 cases with mitral valve area, less than 1.0cm2 demonstrated left ventricular diastolic filling pressure gradient (MVG) of 17.3mmHg in average, the pulmonary vascular resistance of 568 dyndsecd cm(-5) in average, and the right ventricular peak systolic pressure of 72mmHg in average respectively. In all instances, the right ventricular end-diastolic pressure was 11.2mmHg in average and right ventricular peak dp/dt was 571mmHg in average. 4) Among 22 cases with mitral insufficiency, and/or mitral stenoinsufficiency 16 cases showed mean left ventricular end-diastolic pressure elevated more than 0-12mmHg. 10 cases out of these 16 cases disclosed also right ventricular end-diastolic pressure elevated more than 0-8 mmHg. These 16cases of mitral insufficiency and/or mitral stenoinsufficiency had cardiac function more than class III clinically. 5) 16 cases with mitral insufficiency and/or mitral stenoinsufficiency who had mean left ventricular end-diastolic pressure more than 0-12 mmHg showed pulmonary vascular resistance, 358 dyndsecd cm(-5) in average, systemic vascular resistance, 1621 dyne/sec/cm5 in average and left ventricular peak dp/dt, 768-2102mmHg/sec in range. 6) Pulmonary hypertension elevated more than 50mmHg of pulmonary arterial systolic pressure was found in 14 cases out of 18 case with mitral stenosis and in 10 cases out of 22 cases with mitral stenoinsufficiency and/or mitral insufficiency. Pulmonary vascular resistance, however, was markedly variable.

Wolff-Parkinson-White Syndrome and Pre-excitation Dysrrhythmia

Since its initial description in 1930, the preexcitation or Wolff-Parkinson-White(W-P-W) syndrome is characterized by a special electrocardiographic pattern and various paroxysmal tachyarrhythmia, which was found to have reciprocating tachycardia frequently. The W-P-W syndrome develops when some part of a ventricle is activated earlier than normal conduction pathway, and described as one type of ventricular preexcitation syndromes by Durrer (1974). The diagnostic criteria of the W-P-W syndrome are 1) initial slurring (delta wave) of the QRS complex, 2) short P-R interval, 3) widened QRS complex and 4) secondary T wave change. The initial slurring of the QRS complex (delta wave) which is the most important finding of preexcitation syndrome results from a premature activation of a portion of the ventricle through an accessary pathway which bypasses the A-V node and bundle. These accessary conduction fiber includes Kent's bundle, Jame's fibers, Mahaim's fibers and its combination. Recent developments in the field of electrophysiology and surgical therapy became to support the concept of anomalous pathways and the possible determination of the re-entry circuit of paroxysmal tachycardia. Total 12 cases including 9 cases of classical W-P-W syndromes and 3 cases of L-G-L syndromes were followed with special interest of pre-excitation phenomenon and paroxysmal tachyarrhythmia at the National medical Center during the period of Jan. 1975 to Feb. 1979 and found to have paroxysmal tachyarrhythmia in 8 cases out of 12 cases. His bundle electrogram (HBE) and right atrial pacing were recoded in 2 cases of W-P-W type B to support the existance of an anomalous pathway. Treatment was instituted in accordance with recent advanced knowledge for the paroxysmal tachyarrhymia and pre-excitation and references were reviewed.