Reproducibility and diurnal variation of heart rate variability in predischarge period of acute myocardial infarction

BACKGROUND: Decreased heart rate variability(HRV) has been shown to be an independent predictor of poor outcome after acute myocardial infarction, Spectral analysis of HRV has recently been shown to be a reliable noninvasive test for quantiative assessment of cardiovascular autonomic regulatory response. We estimated the reproducibility and circadian rhythm of HRV parameters in patients with acute myocardial infarction. METHODS: Three consecutive 24-hour ambulatory electrocardiographic recordings were made in 24 patients with acute myocardial infarction, with 10~14 days after the acute attack, and analyzed for HRV parameters of both frequency and time domains. Parameters of frequency domain include low frequency(LF) and high frequency(HF) components. Parameters of time domain include sdRR, SDANN, SD, pNN50, rMSSD, HRV index. RESULTS: Mean total, low frequency and high frequency amplitude spectral densities were 33msec, 19msec and 11msec, respectively. Mean values of sdRR, SDANN, SD, rMSSD, pNN50 and HRV index were 103msec, 90msec, 47msec, 28msec, 7% and 32, respectively. Coefficients of variation(CV) of total amplitude spectral density, and low and high frequency components were 7%, 9% and 12%, respectively. CV of most HRV parameters of time domain were also around 10% except rMSSD and pNN50. Heart rate increased in the morning to be sustained during the day time and decreased in the night. Heart rate variability of high frequency component decreased in the early morning to be sustained during day time with increase in the night. CONCLUSIONS: We conclude that in the predischarge period of acute myocardial infarction, HRV parameters of frequency and time domains are reproducible and there are some morning fall of cardiac vagal activity.

Comparisons of Electrocardiograms and Echocardiograms in Soccer Players before and after Intensive Training

BACKGROUND: In athlete's heart, functional and structural alteration are main features. We studied electrocardiograms(ECG's) and echocardiograms(UCG's) in soccer players before and after intensive training. METHODS: Fifteen soccer players with the mean age and career of 19.3 and 8.5 years,respectively,underwent intensive training for 5-5.5 months, which included running of 2 km daily during the last 2-2.5 months. Comparisons of ECG's and UCG's recorded before and after the training were made. RESULTS: The major abnormal finding in pre-training ECG's was high voltage being seen in 40% of the cases, and in UCG's left ventricular(LV) dilatation and/or hypertrophy or asymmetrical septal hypertrophy(ASH) were noted in approximately 80% of the cases. The incidences of these finding after the intensive training were essentially unchanged, and the mean of pre-and post-training fractional shortening(FS) and LV and left atrial dimensions were similar. The high voltage in ECG's showed no close correlation with LV dilatation or hypertrophy on UCG's. After the training, however, the mean values of the thickness of LV posterior wall and ventricular septum along with LV mass were significantly increased, and the right ventricular dimension was significantly decreased. CONCLUSIONS: The most frequent finding in ECG's and UCG's in soccer players, before and after intensive training,were high voltage, LV dilatation and /or hyperophy with or without ASH. The intensive training of 5-5.5 months duration caused no change in F8,but caused significant increase in the thickness of LV posterior wall and ventricular septum, and LV mass.

Effects of Intensive Training on Cardiorespiratory Response to Maximal Exercise Loading in Soccer Players

BACKGROUND: In order to investigate the effects of intensive training on cardiorespiratory response to maximal exercise in soccer players, graded excercise stress tests were carried out before and after the training, and the results were compared. METHODS: Fourteen male soccer players of a university team with the mean age and career of 19.9 and 7.8 years, respectively, underwent intensive training for approximately 20 weeks, 6 days a week and 4 hours a day, which included running of 2 km daily during the last 8-9 weeks. The symptom-limited maximal exercise test was done by Bruce protocol. RESULTS: After the training. HR max showed no significant changes but Vo2 max, O2 pulse and AT were increased approximately 13%, 12% and 10%, respectively. At maximal exercise, the V(E)/M2 was also increased 18%, but VE/MVV was significantly decreased owing to a marked increase in MVV. However, the rest of various ventilatory parameters showed no significant changes. CONCLUSION: These data indicate that the intensive training of about 20 weeks duration can further improve the level of cardiorespiratory fitness in the soccer players who have been regularly trained and are already highly fit.

Adenosine 99mTc-MIBI scintigraphy in the diagnosis of coronary arte= ry disease comparison with exercise 99mTc-MIBI scintigraphy / 대한핵의학회잡지

No abstract available.

Comparisions of Electrocardiograms and Echocardiograms in Volleyball Players before and after Intensive Training

BACKGROUND: We attempted to study functional and structural changes in the hearts of volleyball players and cardiac effects of a short-term intensive training as disclosed by electrocardiograms(ECG's) and echocardiograms(UCG's). METHODS: In 12 volleyball players of a university team with the mean age and career of 19.9 and 9.2 years, respectively, comparisons of ECG's and UCG's M-mode & Doppler, were made before and after an intensive training of 8 weeks duration. The players have been trained 2-3 hours daily almost year around for many years, and the intensive and comprehensive training given for the current study was 3 hours daily, which included strenuous interval training of 20-30 minutes. The training was divided into two successive sessions. For the first session, the players ran 4km daily as a part of the training for 2 weeks. The second session included repetition of runnging at their maximal speed with short intermissions of stationary running for 6 weekes. RESULTS: The major findings in ECG's were sinus bradycardia(25.0%) and high voltage(33.3%), and those in M-mode UCG's were left ventricular(LV) hypertrophy, LV dilatation or left atrial dilatation being seen in all cases, alone or in combinations. After the training however, there were no significant changes in the incidences of these abnormal findings in ECG's & UCG's, and also in the mean of various echocardiographic parameters reflecting cardiac functions. The E and A waves in Doppler UCG's also showed no changes. The slight but significant changes after the training were limited to the increases in the mean of the sum of S wave in V1 & R wave in V5, and left atrial dimensions. CONCLUSION: In volleyball players who have been regularly trained for many years, the major findings in ECG's were sinus bradycardia and high voltage. Those in UCG's were LV hypertrophy. LV dilatation or left atrial dilation being seen in all cases, alone or in combinations. Nonetheless, after the intensive training of 8 weeks duration, the incidences of these abnormal findings in ECG's and UCG's remained essentially similar, and slight but significant changes were limited to the increases in the sum of S wave in V1 & R wave in V5, and left atrial internal dimensions. These facts suggest that in the regularly trained volleyball players, a short-term intensive training induces only limited cardiac changes as disclosed by ECG's and UCG's.

Effect of Lovastatin on Serum Lipids in Primary Hypercholesterolemia

10 Patients with primary hypercholesterolemia were treated for 12 weeks with lovastation(20mg t.i.d). Lovastatin reduced mean total and low density lipoprotein cholesterol by 43% and 57% respectively(p<0.001). High density lipoprotein cholesterol and triglyceride levels were unchanged by the drug. Adverse effects attributable to lovastatin were not observed. Thus lovastatin is considered as an effective lipid lowering agent for the treatment of primary moderate hypercholesterolemia.

Evaluation of Severity of Coronary Artery Disease by Exercise Electrocardiographic Test

Exercise-induced ischemic ST responses were analyzed in 36 patients who presented with chest pain and had exercise test and the results were compared with their coronary angiographic findings. Among 36 exercise test positives, the incidences of one-, two- and three vessel disease, and left main disease were 25%(9 cases), 30%(11 cases), 25%(9 cases) and 9%(3 cases), respectively. The incidence of multivessel disease(i.e., two-to three vessel disease or left main disease) in patients with ST depression > or =2.0mm was 72% and that in those with ST depression of 1.0-1.9mm was 45%. In patients with downsloping ST depression, the incidence of multivessel disease was significantly higher than that of one vessel disease(86% vs 14%, p<0.001). But both incidences of one vessel disease and multivessel disease were similar in patients with flat and slowly upsloping ST depression. More than two thirds of patients with ischemic ST depression appearing in the first 6 minutes of exercise or those lasting past 7 minutes in recovery were associated with multivessel disease. It is concluded that attention to depth, type, appearance time and duration of ST depression during exercise test is particularly helpful in detecting patients with advanced coronary disease.