Jae-Eun Jun

Intravascular ultrasound guided recanalization of stumpless chronic total occlusion

BACKGROUND The recanalization success rate of blunt and vague stump (stumpless) CTO lesions, especially those with a side branch arising from the occlusion, has been significantly lower than that of tapered stump CTO lesions. Intravascular ultrasound (IVUS) may be useful to identify the occlusion point and may facilitate the passage of guide-wires. We evaluated the clinical feasibility of the IVUS-guided wiring technique for stumpless CTO lesions. METHODS Thirty-one consecutive patients (7 women; mean age: 61.0 ± 8.9 years) with 32 lesions were enrolled. The IVUS catheter was introduced into the side branch and it was withdrawn from the side branch to find the entry point of the occlusion, trying to engage another stiffer guide-wire on the occlusion point with the help of real-time IVUS imaging. RESULTS The left anterior descending artery was the most common target-lesion location (22 lesions [69%]). CTO lesions were successfully reopened in 26 lesions (81%). IVUS guidance allowed confident navigation of the stiff guide-wires. The entry point could not be identified in one, and full guide-wire passage was impossible in 4 with the IVUS guidance; TIMI 3 flow could not be achieved even after stent deployment in 1. Although procedure-related complications developed in 8 lesions (25%), no events were serious. Emergent operation was not needed and death or fatal myocardial infarction did not develop during or after the procedures. CONCLUSIONS The IVUS-guided wiring technique is useful and safe for the recanalization of stumpless CTO lesions and might be a valuable tool for the recanalization of complex CTO lesions.

Suboptimal use of evidence-based medical therapy in patients with acute myocardial infarction from the Korea Acute Myocardial Infarction Registry: Prescription rate, predictors, and prognostic value

BACKGROUND Only limited data are available for the recent trend of optimal evidence-based medical therapy at discharge after acute myocardial infarction (AMI) in Asia. We evaluated the predictors for the use of optimal evidence-based medical therapy at discharge and the association between discharge medications and 6-month mortality after AMI. METHODS Between November 2005 and January 2008, we evaluated the discharge medications among 9,294 post-MI survivors who did not have any documented contraindications to antiplatelet drugs, beta-blockers, angiotensin-converting enzyme inhibitors (ACE-Is)/angiotensin II receptor blockers (ARBs), or statins in the Korea Acute Myocardial Infarction Registry. Optimal evidence-based medical therapy was defined as the use of all 4 indicated medications. RESULTS Of these patients, 4,684 (50.4%) received all 4 medications at discharge. The discharge prescription rates of antiplatelet drugs, beta-blockers, ACE-Is/ARBs, and statins were 99.0%, 72.7%, 81.5%, and 77.2%, respectively. In multivariate analysis, advanced age, lower systolic blood pressure, higher Killip class at admission, left ventricular systolic dysfunction, higher blood creatinine level, lower total cholesterol levels, and coronary artery bypass grafting during hospitalization were independently associated with less use of optimal evidence-based medical therapy. In contrast, patients who underwent percutaneous coronary intervention were more likely to use optimal medications. In Cox proportional hazards model, optimal evidence-based medical therapy was an independent predictor of 6-month mortality after adjusting clinical characteristics and angiographic and procedural data. CONCLUSIONS The optimal evidence-based medical therapy is prescribed at suboptimal rates, particularly in patients with high-risk features. New educational strategies are needed to increase the use of these secondary preventive medical therapies.

Clinical characteristics of defecation and micturition syncope compared with common vasovagal syncope.

Background: Little is known about the clinical characteristics of patients with situational syncope such as defecation syncope (DS) or micturition syncope (MS) compared with those with common vasovagal syncope (VVS).

Erroneous Computer Electrocardiogram Interpretation of Atrial Fibrillation and Its Clinical Consequences

The aim of this study was to determine the frequency and nature of errors made by computer electrocardiogram (ECG) analysis of atrial fibrillation (AF), and the clinical consequences.

Complications of 2-D Echocardiography Guided Transfemoral Right Ventricular Endomyocardial Biopsy

Endomyocardial biopsy (EMBx) is a useful tool for diagnosing various cardiac pathologies. However, the routine use of EMBx has not gained widespread acceptance due to the possible complications related to the EMBx. Thus, not much information is available on the complications related to the EMBx. We prospectively evaluated 90 consecutive patients who underwent 2-D echocardiography guided transfemoral right ventricular EMBx at Kyungpook National University Hospital between March 2002 and November 2005 to determine the incidence, nature and subsequent management of complications related to EMBx. The clinical diagnoses before the EMBx were arrhythmogenic right ventricular dysplasia in 54, dilated cardiomyopathy in 19, Brugada syndrome in 9, myocarditis in 6 and miscellaneous in 2 patients. The overall major complication rate was 5.6% and no procedure-related mortality occurred. Myocardial perforation (n=3), which was the most frequent complication, did not progress to cardiac tamponade requiring pericardiocentesis in any patient. Hemodynamically unstable ventricular tachycardia occurred in 1 patient. New and persistent right bundle branch block occurred in another. Our findings suggest that 2-D echocardiography guided transfemoral right ventricular EMBx is a relatively safe procedure.

Electrocardiography patterns and the role of the electrocardiography score for risk stratification in acute pulmonary embolism.

Background and Objectives Data on the usefulness of a combination of different electrocardiography (ECG) abnormalities in risk stratification of patients with acute pulmonary embolism (PE) are limited. We thus investigated 12-lead ECG patterns in acute PE to evaluate the role of the ECG score in risk stratification of patients with acute PE. Subjects and Methods One hundred twenty-five consecutive patients (63±14 years, 56 men) with acute PE who were admitted to Kyungpook National University Hospital between November 2001 and January 2008 were included. We analyzed ECG patterns and calculated the ECG score in all patients. We evaluated right ventricular systolic pressure (RVSP) (n=75) and RV hypokinesia (n=80) using echocardiography for risk stratification of acute PE patients. Results Among several ECG findings, sinus tachycardia and inverted T waves in V1-4 (39%) were observed most frequently. The mean ECG score and RVSP were 7.36±6.32 and 49±21 mmHg, respectively. The ECG score correlated with RVSP (r=0.277, p=0.016). The patients were divided into two groups {high ECG-score group (n=38): ECG score >12 and low ECG-score group (n=87): ECG score ≤12} based on the ECG score, with the maximum area under the curve. RV hypokinesia was observed more frequently in the high ECG-score group than in the low ECG-score group (p=0.006). Multivariate analysis revealed that a high ECG score was an independent predictor of high RVSP and RV hypokinesia. Conclusion Sinus tachycardia and inverted T waves in V1-4 were commonly observed in acute PE. Moreover, the ECG score is a useful tool in risk stratification of patients with acute PE.

The impact of circadian variation on 12-month mortality in patients with acute myocardial infarction.

Background and Objectives Although circadian variation in the onset of acute myocardial infarction (AMI) has been reported in a number of studies, not much is known about the impact of circadian variation on 12-month mortality. The aim of this study was to investigate the impact of circadian variation on 12-month mortality in patients with AMI. Subjects and Methods Eight hundred ninety two patients (mean age 67±12; 66.1% men) with AMI who visited Kyungpook National University Hospital from November 2005 to December 2007 were included in this study. Patients were divided into groups based on four 6-hours intervals: overnight (00:00-05:59); morning (06:00-11:59); afternoon (12:00-17:59) and evening (18:00-23:59). Results Kaplan-Meier survival curves showed 12-month mortality rates of 9.6%, 9.1%, 12.1%, and 16.7% in the overnight, morning, afternoon, evening-onset groups, respectively (p=0.012). Compared with the morning-onset AMI group, the serum creatinine levels (p=0.002), frequency of Killip class ≥3 (p=0.004), and prescription rate of diuretics (p=0.011) were significantly higher in the evening-onset AMI group, while the left ventricular ejection fraction (p=0.012) was significantly lower. The proportion of patients who arrived in the emergency room during routine duty hours was significantly lower in evening-onset groups irrespective of the presence or absence of ST-segment elevation (p<0.001). According to univariate analysis, the 12-month mortality rate in the evening group was significantly higher compared to the morning group (hazard ratio 1.998, 95% confidence interval 1.196 to 3.338, p=0.008). Conclusion Patients with evening-onset AMI had poorer baseline clinical characteristics, and this might affect the circadian impact on 12-month mortality. Further studies are needed to clarify the role of circadian variation on the long-term outcome of AMI.

Prognosis and natural history of drug-related bradycardia.

Background and Objectives The prognosis and natural history of bradycardia related to drugs such as beta-blockers and non-dihydropyridine calcium channel blockers are not well known. Subjects and Methods We retrospectively analyzed 38 consecutive patients (age 69±11, 21 women) with drug-related bradycardia (DRB) between March 2005 and September 2007. A drug-associated etiology for the bradycardia was established based on the medical history and patient response to drug discontinuation. The mean follow-up duration was 18±8 months. Results The initial electrocardiogram (ECG) showed sinus bradycardia (heart rate ≤40/min) in 13 patients, sinus bradycardia with junctional escape beats in 18 patients, and third-degree atrioventricular (AV) block in seven patients. Drug discontinuation was followed by resolution of bradycardia in 60% of patients (n=23). Among them, five (17.8%) patients resumed taking the culprit medication after discharge and none developed bradycardia again. Bradycardia persisted in 10 (26.3%) patients despite drug withdrawal, and a permanent pacemaker was implanted in seven of them. Third-degree AV block, QRS width, and bradycardia requiring temporary transvenous pacing were significantly associated with the bradycardia caused by drugs. Conclusion Beta-blockers were the most common drugs associated with DRB. However, in one quarter of the cases the DRB was not associated with drugs; in these patients permanent pacemaker implantation should be considered.

Gender Differences Among Korean Patients With Coronary Spasm

Background and Objectives The gender differences among Korean patients with coronary spasm have not been defined. We thus determined the gender differences among Korean patients with coronary spasm. Subjects and Methods Patients with chest pain and/or syncope who were admitted to Kyungpook National University Hospital between January 2001 and August 2008 were included. Provocation of coronary vasospasm with intracoronary ergonovine maleate was performed when baseline coronary angiography showed no significant stenosis or there was a strong clinical suspicion of coronary spasm. The clinical characteristics were analyzed from 104 consecutive patients (56±9 years of age; 21 females) who were diagnosed with coronary spasm. Results Female patients were younger (52±7 vs. 57±10 years, p=0.046) with lower rates of smoking and alcohol consumption histories than male patients (19% vs. 65%, p<0.001; and 43% vs. 89%, p<0.001, respectively). The other clinical characteristics were not significantly different, except for the triglyceride levels. Conclusion The majority of patients with coronary spasm were males who were smokers and alcohol consumers. The female patients had lower rates of smoking and alcohol consumption, and they were younger than the male patients. Further studies are needed to investigate the relevance of gender differences in the pathogenesis of coronary spasm.

Examining the relationship between triggering activities and the circadian distribution of acute aortic dissection.

Background and Objectives There are limited data examining triggering activities and circadian distribution at the onset of acute aortic dissection (AAD) in the context of diagnostic and anatomical classification. The aim of this study was to further investigate this relationship between triggering activities and circadian distribution at the onset of AAD according to diagnostic and anatomic classification. Subjects and Methods A total of 166 patients with AAD admitted to Kyungpook National University Hospital between July 2001 and June 2009 were included. To assess the influence of diagnostic and anatomical classification, we categorized the patients into intramural hematoma (IMH) group (n=67)/non-IMH group (n=99) and Stanford type A (AAD-A, n=94)/type B (AAD-B, n=72). To evaluate circadian distribution, the day was divided into four 6-hour periods: night (00-06 hours), morning (06-12 hours), afternoon (12-18 hours), and evening (18-00 hours). Results Most (72%) AAD episodes were related to physical (53%) and mental activities (19%), with about one-third occurring during the afternoon, and only 12% occurring at night. No differences in triggering activities or circadian distribution were observed among the groups. Waking hours including morning, afternoon, and evening correlated with triggering activities (p=0.003). These relationships were observed for the non-IMH (p=0.008) and AAD-B (p=0.003) cases. The remaining categories had similar relationships, but did not reach statistical significance. Conclusion Our findings suggest differences in the relationship between triggering activities and the circadian distribution of the onset of AAD according to diagnostic and anatomical classification.