Enhancement of Gene Delivery into Mouse Skeletal Muscle with Microbubble Destruction by Low-Frequency Ultrasound

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate the value of microbubble destruction using low-frequency ultrasound for enhancing gene delivery to skeletal muscles of laboratory animals. MATERIALS AND METHODS: Lac-Z gene was injected into 21 mouse anterior tibialis muscles. Seven muscles received the gene only, and seven each received either 20-kHz ultrasound exposure or ultrasound-PESDA (perfluorocarbon-exposed sonicated albumin) destruction, respectively, following the injection; the extent of Lac-Z expression was then compared. Luciferase gene was injected into the muscles (N=80). The muscles were divided into two groups according to the mixture; in the first group saline was used as the mixture solute, with PESDA used in the second group. The groups were subdivided into two groups, one receiv 10 seconds of ultrasound at the injection site after injection, and the other that received no further intervention. Luciferase activities were measured and compared. RESULTS: The proportions of Lac-Z stained cells were 0, 5.7+/-1.2 and 7.7+/-1.7%, respectively, showing a significant stepwise increase microbubble destruction (p<0.05). Luciferase activities were as follows: Luciferase only (Group 1, N=17), 5727+/-2178 RLU/mg; luciferase plus PESDA (Group 2, N=17), 1170+/-470.7 RLU/mg; luciferase plus ultrasound (Group 3, N=17), 16480+/-5239 RLU/mg; and luciferase plus PESDA destruction (Group 4, N=17), 49910+/-16500 RLU/mg. The activity in group 4 was significantly higher than in group 1 (p<0.01), showing an 8.7-fold increase in gene delivery due to microbubble destruction. CONCLUSION: Microbubble destruction using low-frequency ultrasound is an efficient method for increasing the efficacy of direct gene delivery to skeletal muscles.

Study of Compliance to Antihypertensive Medication in Korean Hypertensive Patients Using Medication Event Monitoring System

BACKGROUND AND OBJECTIVES: Compliance to a prescribed antihypertensive regimen influences the management of hypertension in various steps, but studies on this issue are very rare in Korea. The medication event monitoring system (MEMS) is the gold standard in measurement of compliance, which is a special pill container, designed to electronically monitor drug intake patterns. Here, the authors investigated the compliance to the antihypertensive regimen in the cardiology practice of a tertiary care hospital using the MEMS. SUBJECTS AND METHODS: Monitoring using the MEMS was performed in 80 hypertensive patients during monotherapy. Demographic, clinical and psychological profiles were collected through a standardized questionnaire. The parameters used for compliance were the percentage of doses taken (PDT) and the percentage of doses taken correctly (PDTc), according to the prescribed regimen. RESULTS: The mean age of the patients and duration of monitoring were 53+/-10 years and 60+/-26 days, respectively. The median and range for the PDT and PDTc were 97% (88-100%) and 92% (80-97%), respectively. About 16% of patients showed relatively poor compliance (PDT<80%). Predicting factors for poor compliance were a recent history of self-discontinuation of drug treatment, not currently being on medication and a young age (p<0.05). Agreement between intuitive prediction by the physician and the actual compliance was closer to what would be expected by chance (kappa coefficient=-0.11). CONCLUSION: Although average compliance to the single drug antihypertensive regimen was relatively high in the cardiology practice of the tertiary care hospital in this study, a significant proportion of patients show low compliance. Special consideration should be given to patients with factors predictive of poor compliance. Investigation of compliances in other clinical settings is also warranted.

Correlation between Vascular Compliance and Increase of Blood Pressure on Exercising in Normotensive Group

BACKGROUND AND OBJECTIVES: Vascular compliance is known to be decreased in hypertension, even at an early stage. The blood pressure response to exercise reflects the future risk of developing hypertension. A study was performed on the relationship between the vascular compliance and blood pressure response to exercise, to evaluate whether the vascular compliance is decreased in normotensive persons with a relatively higher future risk of developing hypertension. SUBJECTS AND METHODS: The subjects of the study were adults with normal blood pressure (SBP<120 mmHg, DBP<80 mmHg), who had undergone health screening and both echocardiography and treadmill test. Those patients with a history of diabetes mellitus or clinical cardiovascular diseases were excluded form the subjects. An index of overall vascular compliance (SVI/PP) was calculated using echocardiography. The relationship between the peak systolic blood pressure during exercise and vascular compliance was also investigated. RESULTS: The subjects were 77 patients, 54 male and 23 female, with a mean age of 47.6+/-7.7 years. The measured vascular compliance and average of peak systolic pressure on exercising were 1.08+/-0.24 L/m2/mmHg and 154+/-21 mmHg, respectively. The peak systolic pressure was correlated with the vascular compliance (r=-0.24, p<0.05). The peak systolic pressure at stage 3 was also correlated with the vascular compliance (r=-0.24, p<0.05). This relationship persisted after adjustment for age, gender, basal systolic blood pressure and maximal oxygen consumption (p<0.05). CONCLUSION: The vascular compliance was lower in subjects with a larger increase in blood pressure during exercise whose basal blood pressure was even below 120/80 mmHg. This finding may suggest that a decreased vascular compliance precedes the changes of hypertension. A longitudinal follow-up study is warranted.

Safety of One-Day Admission Transradial Coronary Intervention

BACKGROUND: Recent advances of percutaneous coronary intervention (PCI) and transradial coronary intervention (TRI) have made it possible to reduce the local complication rate and the time until a return to ambulation. The aim of this study is to assess the safety and the patient satisfaction of the TRI-based one-day admission program for PCI. METHODS: Total 230 consecutive patients underwent TRI on the day of admission, according to pre-determined inclusion criteria, from May 2001 to October 2003. The subjects were examined for clinical and angiographic characteristics. The patients having a same-day discharge were telephone-interviewed one day and seven days after discharge to assess late complications and the patients' satisfaction. RESULTS: The mean age of the subjects was 59+/-9 years and 77.4% were male patients. 169 (73.4%) had stable angina and 37 (16.1%) had unstable angina. Stents were implanted in 178 cases (69.3%). Of the 230 patients who underwent TRI, 206 patients (89.6%) could discharge on the same day after the procedure. The procedure was successful in 98.5%. The average hospital stay for them was 9.4+/-1.4 hours. Two subjects reported hematoma near the puncture site within 24 hours after discharge, and one reported this problem 7 days after discharge. During the follow-up, there were no cases reporting chest pain needing rehospitalization or such complications as subacute vessel closure. No deaths, myocardial infarctions or revascularization were noted during the follow-up period. The majority of the patients (n=197, 95.6%) were satisfied with the same-day admission and discharge. CONCLUSIONS: Same day admission and discharge after TRI seems to be safe as well as satisfactory for not low-risk patients.

Predictors of Sinus Rhythm Restoration after Maze Operation and Relationship between Pre- and Post-operative Left Atrial Volume

BACKGROUND AND OBJECTIVES: The Maze operation is known to be an effective measure for restoring sinus rhythm in patients with atrial fibrillation (AF). The purpose of this study was to identify the relationship of pre- and post-operative left atrial volume (LAV) and diameter (LAD) with successful restoration of sinus rhythm in the Maze operation. SUBJECTS AND METHODS: The subjects for this study were 28 patients who underwent open-heart surgery in conjunction with the Maze-III operation for chronic AF from October, 2002, to April, 2003. Electrocardiographic and transthoracic echocardiographic studies were done pre-operatively and three months post-operatively. LAV and LAD were assessed and corrected for body surface area (LAV index=LAV/BSA, LAD index=LAD/BSA). RESULTS: Sinus rhythm was restored and maintained in 22 of the 28 patients (78.6%). Between the group with successful restoration of sinus rhythm (Group A;n=22) and the group with unsuccessful restoration (Group B;n=6), there was no difference in age, gender, and NYHA functional class. The duration of AF in group A was significantly shorter than that of B (3.6+/-2.7 years versus 15.8+/-7.5 years, p=0.003). Group A and B did not show any difference in pre-operative left ventricular ejection fraction. However, pre-operative LAV index in group A was significantly smaller than that of group B (80.7+/-22.4 mL/m2 versus 118.1+/-42.5 mL/m2, p=0.048). In group A, the LAV index (80.7+/-22.4 mL/m2 versus 52.8+/-14.7 mL/m2, p<0.001) and LAD index (35.4+/-5.3 mm/m2 versus 31.7+/-4.7 mm/m2, p=0.001) decreased significantly three months after the operation. In group B, however, no significant changes are found in the LAV index (118.1+/-42.5 mL/m2 versus 89.2+/-38.9 mL/m2, p=0.116) and LAD index (39.1+/-7.9 mm/m2 versus 36.2+/-9.2 mm/m2, p=0.144). CONCLUSION: Pre-operative LAV index measured by echocardiography and the duration of AF were significant predictors of successful sinus rhythm restoration after the Maze operation. Significant reduction of the LAV index after the Maze operation was found in patients whose rhythm was successfully restored and maintained.

A Qualitative Evaluation of Problem-Based Learning Curriculum by Students' Perceptions / 한국의학교육

PURPOSE: Recently established in 1997, Sungkyunkwan University School of Medicine was the first medical school in Korea to adopt problem-based learning (PBL) as a core curriculum from the very beginning. The purpose of this study was to evaluate the PBL curriculum from the viewpoint of the medical students. METHODS: This study used a qualitative approach to understand students' perceptions of the positive aspects of PBL. A total of 22 second-year medical students at Sungkynkwan medical school were surveyed. Student perceptions were obtained from questionnaires and face-to-face interviews. The interview was designed to evoke more personal and in-depth responses. RESULTS: Students' perceptions of the effects of PBL were found to be very favorable. Most students showed positive responses on the issues of more active learning attitude, self-directed learning, motivation to study, improved problem solving, and integrated learning. CONCLUSION: The results of this study demonstrated that the students had a good understanding of PBL and experienced its positive aspects of PBL approach. It might be concluded that PBL was successfully implemented into the curriculum and specific and expected effects of PBL accomplished.

The efficacy and safety of angioseal(R) compared to conventional manual compression after transfemoral percutaneous coronary intervention / 대한내과학회지

BACKGROUND: Although the number and the quality of percutaneous coronary intervention have been recently increased dramatically, the vascular complication at puncture site is still the major cause of patients' morbidity. We evaluated the safety and efficacy of newly-developed collagen-based arterial closure device, angioseal(R) after transfemoral percuatenous coronary intervention. METHODS: This study was designed as a prospective single center non-randomized comparative study. A total 200 patients undergoing transfemoral percutaneous coronary intervention were enrolled between April 2002 and May 2003. They were divided into two groups; angioseal(R) group (group A, n=100) and manual compression group (group B, n=100). The baseline clinical and angiographic characteristics were reviewed. The time to sit up, the time to ambulation, the duration of hospital stay, major and minor vascular puncture site complications were monitored. The patients were followed-up for 1 week after the procedure by telephone. RESULTS: The baseline clinical characteristics, clinical diagnosis, cardiovascular risk factors, types of procedure, doses and numbers of anticoagulants were similar between two groups. The blood pressure and activated clotting time were also similar. The time to sit up (group A: 4.3 0.3 hours, group B: 13.7 0.8 hours, p=0.004) and the time to ambulation (group A: 6.8 0.5 hours, group B: 18.8 2.1 hours, p=0.013) were shorter in group A. No major vascular complications were noted. The incidence of hematoma and bleeding were not significantly different between two groups. The incidence of ecchymosis, however, was significantly lower in group A (group A: 12%, group B: 3%, p=0.001) The duration of hospital stay was similar between two groups. During 7 days of follow-up period, the incidence of hematoma was significantly lower in group A (p=0.004). Although the incidence of ecchymosis was not significantly different between two groups. CONCLUSION: The angioseal(R) may be associated with earlier ambulation and less patients' morbidity with low incidence of local complication rate compared to manual compression after transfemoral percutaneous coronary intervention.

Clinical Aspects of Coronary Artery Perforation during Percutaneous Coronary Intervention

BACKGROUND AND OBJECTIVES: Coronary artery perforation is a rare, but potentially deadly, complication of percutaneous coronary intervention (PCI). The purpose of this study was to analyze the clinical characteristics, and outcome, of coronary artery perforation. SUBJECTS AND METHODS: We retrospectively reviewed 3,782 consecutive PCIs, performed between January, 1994 and May, 2002 at the Samsung Medical Center, from the database records. The medical records and angiograms of the patients were also reviewed. The coronary artery perforations were classified according to Ellis' classification. RESULTS: A coronary artery perforation was noted in 24 patients (0.6%). It was most commonly observed during PCI of the right coronary artery (46%) and a chronic total occlusion intervention (42%). The number of the patients with Ellis'classes I, II and III were 11, 8 and 5, respectively. The most frequent causes of the perforation were guidewire, followed by balloon (11 and 8 cases, respectively). The interventional modality with the highest risk of perforation in this study was rotational atherectomy, (4 out of 157, 2.6%). Five patients had cardiac tamponade, of which four occurred during a rotablator procedure. Pericardiocentesis was performed in 5 patients, while 3 patients with class III perforations received emergent coronary artery bypass surgery. There were no in-hospital mortalities, although the duration of the hospital stay for the class III patients was longer than those with classes I or II perforations. CONCLUSION: A coronary artery perforation during percutaneous coronary intervention is a potentially serious complication. However, the immediate and adequate management results in a fairly good prognosis.

Analysis of P Wave Signal-Averaged Electrocardiogram in Patients with Paroxysmal Atrial Fibrillation

BACKGROUND AND OBJECTIVES: The diagnosis of paroxysmal atrial fibrillation (PAF) and the prediction of its recurrence are sometimes difficult. There have been several recent studies attempting to detect patients at risk for PAF while in sinus rhythm by using the P wave signal-averaged ECG. We undertook to define an appropriate technique of P wave signal-averaged ECG and to estimate the reproducibility of the test. Additionally, we estimated the usefulness of P wave signal-averaged ECG in patients at risk for PAF. SUBJECTS AND METHODS: Forty-five patients with PAF were included in the study undertaken between March 1997 and June 1998. Twelve-lead surface ECG and P wave signal-averaged ECG were performed in the patients. The total P wave duration was measured by the P wave signal-averaged ECG using P wave template and least-square fit filter. The same process was followed in forty sex- and age-matched controls. RESULTS: The measurement of P wave duration with P wave signal-averaged ECG was highly reproducible. The measured P wave duration showed significant prolongation in the patient group at cutoff frequencies of 20 Hz and 30 Hz (123.6+/-15.3 vs. 114.8+/-14.5 msec, p=0.009 at 20 Hz, 120.1+/-17.8 vs. 107.5+/-18.8 msec, p=0.002 at 30 Hz). An abnormal P wave duration defined as over 120 msec in duration by P wave signal-averaged ECG was able to detect PAF with a sensitivity of 60%, specificity of 73%, positive predictive value of 71%, and a negative predictive value of 62%. CONCLUSION: A prolonged P wave duration as measured by P wave signal-averaging technique may be a simple noninvasive marker of risk for the development of atrial fibrillation.

Study on Establishment of Disease Database and Query System Through Internet Using Uniform Hospital Discharge Data Sets / 대한의료정보학회지

It is necessary to have accurate statistical data of disease for planning and evaluating public health policy as well as assessing population health index. The national health insurance data is the only data to assess incidence of diseases nation-wide. However, inaccuracy of the data pose serious limitations of use of the data. The Medical Record Departments of individual health facilities have used discharge summary information for hospital management and clinical research, but a nation-wide integrated database of diseases has not been setup and utilized. We applied previously developed Korean Uniform Hospital Discharge Data Sets to collect discha rge summary data from health care facilities and establish integrated database. We also made the question and answer column about disease of the database in the internet. We collected patient discharge data from a tertiary-care hospital for one year using the electronic discharge summary data collection system, except for health care costs. The internet querying system provided optional selection of columns or rows, individual and/or disease groups and surgical procedures. To make query easy, the system provided various functions like querying codes of diseases and/or surgical operations, reviewing questions, downloading results via excel files, help functions of query. The establishment of disease database and the interactive system through internet is in its inception, further studies may be necessary to make it a user friendly and accurate system. There is a need of an accurate assessment of current population-based health status and future trends in Korea. It is hoped that this study may trigger to establish national accurate database for enhancing studies of health policy making, clinical research and vital health statistics by expanding data collections to the se condary- care and primary- care institutions.

Effect of Vigorous Preload Reduction on Mitral Annulus Velocity in Chronic Renal Failure

BACKGROUND AND OBJECTIVES: The pulsed wave Doppler echocardiography in the mitral inflow is used widely for the assessment of LV diastolic function. The echocardiographic index of LV diastolic function is known to be affected by several factors, such as the loading condition. In the Doppler tissue image (DTI), the mitral annulus velocity is known to be unaffected by the loading condition. The purpose of this study was to investigate the effect of the preload reduction on the mitral annulus velocity. SUBJECTS AND METHODS: We examined the transmitral and pulmonary venous flows, and the mitral annulus velocity in 30 patients with chronic renal failure, but a normal LV systolic function, by echocardiography, both before and after hemodialysis. The study patients were divided into two groups; Group I (preload reduction 2.0 kg, N=20). RESULTS: In the transmitral flow; the E velocity was changed, both before and after hemodialysis, in Group II. < Group I from 97+/-12 cm/s to 86+/-11 cm/s (NS), Group II from 85+/-5 cm/s to 63+/-5 cm/s (p=0.0001)<. The A velocity was also changed in Group II. In the mitral septal annulus velocity by DTI; The E' velocity was changed in both groups, but the A' velocity was only changed in Group II. In the mitral lateral annulus velocity by DTI; all indices remained unchanged in both groups. CONCLUSION: These results suggested that a vigorous preload reduction might change the echocardiographic indices, and either the transmitral flow pattern or the mitral septal annulus velocity. The mitral lateral annulus velocity indices, which are useful for the evaluation of the LV diastolic function, were unchanged by the preload reduction. The preload condition needs to be accounted for when evaluating the LV diastolic function with a Doppler echocardiography.

Clinical Experiences with the Percusurge(r) for the Coronary Lesions with Intracoronary Thrombus

BACKGROUND AND OBJECTIVES: During coronary angioplasty, a distal embolization of the intracoronary thrombus is associated with an increased risk of myocardial infarction and mortality. Recently, distal protection devices have been tested for distal embolization with varying success. Here we report the experiences with one of the distal protection devices, Percusurge(r). SUBJECTS AND METHODS: From January 2001 to August 2001, 5 cases of a Percusurge(r) being used in patients with intracoronary thrombus were experienced during the angioplasty (male:4, female:1). Both the pre- and post-procedural clinical findings of the patients, the angiographic findings, the number of acute complications, the presence of biochemical marker such as CK-MB, and any in-hospital cardiac events were reviewed. RESULTS: Percusurge(r) was used in the right coronary artery (RCA) in 4 cases and in the saphenous vein graft in 1. The clinical diagnosis included stable angina (2 patients), non-Q wave myocardial infarction (1 patient), and Q-wave myocardial infarction (2 patients). The patients showed a TIMI 0 or 1 flow in 4 patients with a RCA lesion and TIMI 3 flow in 1 patient with a saphenous vein graft lesion. However, the TIMI 3 flow was recovered in all cases after the intervention. The CK-MB level did not show any significant changes between the pre- and post-procedure in 4 cases (11.2 +/- 3.2 U/L vs 10.2 +/- 2.1 U/L). However, one of the distal branchs was totally occluded by the distal embolization of the thrombus, and the CK-MB level increased from 2.1 U/L to 22.7 U/L. Otherwise, no procedure-related complications or major in-hospital cardiac events were observed. CONCLUSION: The use of the distal protection device, Percusurge(r), may reduce both the procedural and clinical complications during a coronary intervention in the thrombus-containing lesion. However, a large prospective study is needed to define the role of the distal protection device.

The Risk Factors of Vasospastic Angina

BACKGROUND AND OBJECTIVES: The causes of vasospastic angina are not well known. We attempted to elucidate the risk profiles of Korean patients with vasospastic angina. SUBJECTS AND METHODS: The risk profiles were analyzed in 181 patients with vasospastic angina (VA), 1533 patients with obstructive coronary artery disease (CAD) who underwent coronary angiography at Samsung Seoul Hospital, and 455 normal control subjects, sex and age matched to the VA group and selected from the Health Promotion Center of Samsung Seoul Hospital. The male to female ratio was significantly higher in the VA group (4.6:1) than the obstructive CAD group (2.7:1). The mean age of the VA group (52.2+/-10.7 years) was significantly younger than the mean age of the obstructive CAD group (59.0+/-10.6 years) (p<0.01). Additionally, the smoking rate was significantly higher in the VA group (49.2%) as compared with the obstructive CAD group (43.1%) (p<0.01). Other major risk factors such as hyperlipidemia, hypertension and diabetes mellitus were significantly more prevalent in the obstructive CAD group than the VA group. Among the obstructive CAD group, a subgroup of Q-wave myocardial infarction (MI) showed a significantly higher smoking rate (59.3%) as compared with VA group (49.2%) (p<0.01). CONCLUSION: The VA group showed a higher prevalence in males and younger subjects as compared with the obstructive CAD group, and smoking appeared to be the most important risk factor for VA.

Clinical Manifestation of Novel Stress-induced Cardiomyopathy Mimicking Acute Myocardial Infarction: Single Center Prospective Registry

BACKGROUND AND OBJECTIVES: The so-called 'stress-induced cardiomyopathy' or takotsubo cardiomyopathy, mimicking acute myocardial infarction (AMI), has recently been reported, particularly in Japan. We prospectively studied the clinical characteristics of, for the first time with a Korean series, this novel syndrome. SUBJECTS AND METHODS: Eighteen patients, fore filling the inclusion criteria, were entered onto the study. The criteria for inclusion were: 1) no previous history of cardiac disease, 2) acute onset, 3) a regional wall motion abnormality in the left ventriculogram, typically in the apical segment, and 4) no significant stenosis in the coronary angiogram. RESULTS: The events preceding the condition included: emotional stress (N=7), acute illness (N=5), non-cardiac surgery or medical procedure (N=4) and accident (N=2). Chest pain, dyspnea, or nausea/vomiting were initially noted in 12 cases (66%). Pulmonary edema was demonstrated in 10 (56%), and cardiogenic shock in 4 (23%) of the patients. The peak creatinine kinase MB fraction was 69+/-136 IU/L. A T wave inversion was noted in all patients, whereas, a Q wave was noted transiently in only 1. The average left ventricular ejection fraction (LVEF) was 38+/-8% on the initial echocardiograms. On the left ventriculograms, 15 patients showed akinetic wall motion, or aneurysmal dilatation in the apical wall, however, notably in 3 patients in the mid-ventricular wall. The coronary vasospasm provocation tests were negative in all 10 patients tested. An intravascular ultrasonography showed no infarct-related plaques in the 4 patients examined. On a follow-up echocardiogram, the average LVEF was improved to 51+/-8%, and regional wall motion was normalized after 30+/-29 days following onset. CONCLUSION: We report, for the first time in a series of Korean patients, on a novel stress-induced cardiomyopathy with transient regional wall motion abnormality, mimicking AMI. The precise etiology remains to be elucidated in further studies.

Factors Influencing the Improvement of Left Ventricular Systolic Function in Patients with Idiopathic Dilated Cardiomyopathy

BACKGROUND AND OBJECTIVES: Idiopathic dilated cardiomyopathy (IDC) is a disease entity with no known specific curative measures. However, significant improvement in the left ventricular (LV) systolic function, during the management course for IDC, is frequently observed. In this study we tried to ascertain associated factors for the improvement of the LV function in patients with IDC. SUBJECTS AND METHODS: Thirty-three patients, newly diagnosed as IDC between Jan. 1999 and Jan. 2001, on whom a 6-month follow-up echocardiography was performed, were included in the study. Improvement in the LV systolic function was defined as an increase in the LV ejection fraction greater than 10% from the baseline. The subjects were divided into two groups; the improved group (IG) and the unimproved group (UG). The clinical characteristics and management methods were evaluated, and compared between the two groups. RESULTS: Seventeen patients (M/F:15/2) were included in the IG, and 16 (M/F:7/9) were included in the UG. There were no significant differences in the baseline LV systolic function (IG:23.4+/-1.5% vs. UG:28.9+/-2.3%), age, NYHA functional class or resting heart rate on admission between the two groups. b-blocker therapy (p=0.002), the absence of diabetes mellitus (p=0.046) and male sex (p=0.007), were all significantly associated with an improvement in the LV systolic function from the univariate analyses. With the multivariate analyses, only b-blocker therapy was significantly associated with an improvement in the LV systolic function. The 6-month event-free survival rate was significantly better in the IG compared with UG (94+/-5% vs. 63+/-13%, p=0.031). CONCLUSION: b-blocker therapy exerts a considerable effecs on the improvement in the LV systolic function of patients with IDC.

Impact on Long-term Adverse Cardiac Events of Troponin T or Creatine Kinase-MB Release after Percutaneous Transluminal Coronary Angioplasty

BACKGROUND AND OBJECTIVES: The impact on long-term adverse cardiac events of troponin T (TnT) or creatine kinase-MB (CK-MB) release after percutaneous transluminal coronary angioplasty (PTCA) is not well defined. The purpose of the study is to evaluate the effect of elevated TnT or CK-MB on the late major adverse cardiac events [MACE ; Q wave myocardial infarction (MI), revascularization, or cardiac death]. SUBJECTS AND METHODS: Study population were 207 consecutive patients (M : F=148 : 59, mean 60.8+/-9.2 years) who underwent PTCA. Patients with acute MI, unstable angina with abnormal levels of TnT or CK-MB, or newly developed Q MI after PTCA were excluded. Cardiac enzyme levels were measured before and 8, 24 hours after PTCA for CK-MB, and before and 16 hours after PTCA for TnT. Group I (n=181, 87.4%) had normal levels of both after PTCA. Group II (n=26, 12.6%) had abnormal levels of CK-MB (>or=16 U/L) and/or TnT (>or=0.2 ng/mL). 1-year follow-up was available in 201 (97.1%) patients. RESULTS: Incidence of non-Q MI after PTCA was 26/207 (12.6%). Major complications such as acute coronary occlusion, side branch occlusion, and major dissection were significantly associated with elevation of TnT or CK-MB after PTCA (p=0.01). However, elevation of CK-MB or TnT was not significantly associated with late MACE by Kaplan-Meier survival curve (p=0.46). During 1-year follow-up, event free rate of group I and II were 76.6% and 69.2%, respectively. CONCLUSION: Acute coronary occlusion, side branch occlusion, or major dissection can increase the level of TnT or CK-MB after PTCA. But, elevation of CK-MB or TnT after PTCA dose not significantly influence on late MACE.

Heart Rate Variability in Stable Angina Patients without History of Myocardial Infarction

BACKGROUND AND OBJECTIVES: Heart rate variability(HRV) reflects the autonomic integration of heart. There were many reports that HRV in patients with myocardial infarction or heart failure is an independent prognostic factor to predict fatal arrhythmia and sudden cardiac death. But, the role of HRV is still controversial in stable angina patients without history of myocardial infarction. In this study, we tried to compare HRV indices between stable angina patients and normal subjects. MATERIALS AND METHODS: Twenty-one stable anginal patients without history of myocardial infarction (mean age : 57 +/- 2 years) and twenty-one relatively healthy persons without history of coronary heart disease (mean age : 53 +/- 2 years) were included in the study and underwent 24-hour ambulatory ECG monitoring. In patients group, all underwent coronary angiography after 24-hour ambulatory ECG monitoring. HRV was analyzed over the whole 24 hours, using time and frequency domain parameters, according to time phases and coronary angiographic severity. RESULTS: There were no significant differences in age, sex and cardiovascular risk factors, except hypertension (p=.001) between two groups. HRV indices such as rMSSD, pNN50, LF, HF, LFnorm and HFnorm were significantly decreased (p<0.05) in patients group. But the angiographic severity of coronary arteries did not show any significant effect on the HRV indices in patients group. CONCLUSIONS: We observed significantly reduced HRV indices in patients with stable angina without history of myocardial infarction.

A Case of Permanent Junctional Reciprocating Tachycardia Treated with Radiofrequency Catheter Ablation

Permanent junctional reciprocating tachycardia (PJRT) is an infrequent form of reentrant supraventricular tachycardia. This tachycardia usually occurs in children and young adults and may be associated with tachycardiainduced cardiomyopathy. It is virtually incessant, at a rate ranging from 120 to 250 beats/minute. The characteristic electrocardiogram shows inverted P waves in the inferior leads with a long RP interval (RP greater than PR) during tachycardia. During tachycardia, the cardiac impulse conducts antegradely through the atrioventricular node and His-Purkinje system, returning retrogradely through the slowly conducting accessory pathway. The location of the accessory pathway is usually, but not always, near the ostium of the coronary sinus. Since the advent of radiofrequency catheter ablation (RFCA), several reports have emphasized the usefulness of RFCA for the treatment of PJRT. We report a case of PJRT in a 33-year-old male, successfully treated with RFCA.

Changes of Heart Rate Variability in Patients with Postmenopausal Syndrome after Hormonal Replacement Treatment

BACKGROUND AND OBJECTIVES: Climacteric women often suffer from vasomotor symptoms. These symptoms are thought to be related to an imbalance of autonomic control of the cardiovascular system and are effectively controlled with hormonal replacement therapy. Heart rate variability (HRV) reflects the autonomic integration of the cardiovascular system. In this study, we attempted to compare the HRV indices of postmenopausal women before and after hormonal replacement therapy. SUBJECTS AND METHODS: Eighteen patients with postmenopausal syndrome (mean age:53+/-4 years) received estrogen and/or progesterone replacement therapy. They underwent 24-hour ambulatory electrocardiographic monitoring at baseline and after the early period of therapy (mean:112+/-19 days) and eleven patients underwent the examination after the later period of therapy (mean 213+/-23 days). HRV was analyzed over a full 24-hour period, using time and frequency domain parameters. RESULTS: No statistically significant HRV change was observed during the early period of therapy. However, during the later therpy period , HRV indices such as rMSSD[from 27.6 to 31.3 (msec)], HF[from 4.8 to 5.05 ln (ms2)], LF/HF ratio (from 1.17 to 1.12) were significantly changed (p value<0.05). CONCLUSION: HRV was significantly changed in postmenopausal women during the later period of hormonal replacement therapy.

Role of echocardiography as a screening test in patients with suspected pulmonary embolism

BACKGROUND AND OBJECTIVES: Pulmonary embolism (PE) is a disease with high mortality if left untreated. But, confirmative diagnosis is difficult because many diagnostic modalities are nonspecific. Pulmonary angiography, which is considered as the gold standard diagnostic tool, is invasive, costly, time-consuming, and not always available in small centers. Echocardiography is a non-invasive and available in the emergency room without significant time delay. We investigated the role of echocardiography as a screening test in patients with suspected PE. MATERIALS AND METHODS: (A) Retrospective study: We analyzed the recorded videotapes of transthoracic echocardiography in fifty patients with confirmed PE from Jan 1995 to Aug 1999. From the frequent echocardiographic findings of those patients, positive criteria were defined as followed ( 2 among 1-5 or only 6). (1) RV or pulmonary artery dilatation (RVEDA/LVEDA 0.6) (2) RV hypokinesis (3) paradoxical septal wall motion (4) pulmonary hypertension (5) TR (moderate degree or more) (6) Visible thrombus. Although the degree of TR was less than moderate, if the degree of pulmonary hypertension was more than moderate, we considered as PE. (B) Prospective study: From Nov 1999 to June 2000, patients with suspected pulmonary embolism underwent a transthoracic echocardiography and perfusion-ventilation lung scan or chest CT. We assessed echocardiographic findings, sensitivity and specificity of the previously defined echocardiographic positive criteria for PE. RESULTS: (A) Retrospective study: The sensitivity of echocardiography for PE was 74%. (B) Prospective study: The number of enrolled patients was thirty-four. In twenty patients the diagnosis was PE. The sensitivity of echocardiography was 75% but the specificity was 14%. CONCLUSION: Echocardiography may be used as a good screening test in patients who are clinically suspicious of pulmonary embolism.