Sang Chol Lee

The Clinical Characteristics, Laboratory Parameters, Electrocardiographic, and Echocardiographic Findings of Reverse or Inverted Takotsubo Cardiomyopathy: Comparison With Mid or Apical Variant

Although takotsubo cardiomyopathy (TTC) typically affects the apical and/or midventricular segments, several recent cases have reported a reverse or inverted variant of TTC. The aim of this study was to investigate the clinical characteristics, laboratory parameters, electrocardiographic, and echocardiographic findings in patients presenting as inverted TTC and compare those parameters to those presenting as mid or apical variant.

Frequency of Myocardial Infarction and Its Relationship to Angiographic Collateral Flow in Territories Supplied by Chronically Occluded Coronary Arteries

Background— Despite complete interruption of antegrade coronary artery flow in the setting of a chronic total occlusion (CTO), clinical recognition of myocardial infarction is often challenging. Using cardiac MRI, we investigated the frequency and extent of myocardial infarction in patients with CTO, and assessed their relationship with regional systolic function and the extent of angiographic collateral flow. Methods and Results— We included 170 consecutive patients (median age, 62 years) with angiographically documented CTO. Regional late gadolinium enhancement and wall motion score index were assessed by cardiac MRI with the use of a 17-segment model. Angiographic collateral flow was assessed by the collateral connection grade and the Rentrop score. Evidence of previous myocardial infarction was found in 25% of patients by ECG Q waves, in 69% by regional wall motion abnormality, and in 86% of patients by late gadolinium enhancement. Increased angiographic collateral flow was associated with a lower frequency of Q waves on ECG, and a lower regional wall motion score index, late gadolinium enhancement volume (%), and degree of late gadolinium enhancement transmurality (all P<0.001), as well. Conclusions— The frequency of myocardial infarction in territories subtended by CTO is significantly higher than previously recognized. The degree of myocardial injury downstream epicardial CTO is inversely correlated with the degree of angiographic collaterals.

Clinical characteristics, and laboratory and echocardiographic findings in takotsubo cardiomyopathy presenting as cardiogenic shock

PURPOSE Although takotsubo cardiomyopathy (TTC) has been reported to have an excellent clinical recovery, there are few data regarding clinical, laboratory, and echocardiographic findings in TTC presenting as cardiogenic shock. We aimed to assess the differences in these parameters between TTC presenting with and without cardiogenic shock. METHODS Fifty patients were enrolled from the TTC registry database and divided according to the presence of cardiogenic shock. Sixteen patients presented with cardiogenic shock as initial presentation (S group), and 34 did not (NS group). RESULTS The S group had a higher prevalence of dyspnea (81% vs 38%, P = .005), pulmonary edema (69% vs 29%, P = .009), and significant reversible mitral regurgitation (44% vs 15%, P = .025) than the NS group. In addition, the S group had significantly higher troponin-I (median, 8.2 vs 1.4 pg/mL; P = .043) and N-terminal prohormone brain natriuretic peptide levels (median, 8831 vs 2348 pg/mL; P = .046). During follow-up (median, 3.1 years), cardiac deaths associated with TTC itself and recurrences of TTC were not noted in both groups. CONCLUSIONS The S group has a higher prevalence of heart failure symptoms, significant reversible mitral regurgitation, and troponin-I and N-terminal prohormone brain natriuretic peptide levels. However, with meticulous therapeutic strategies, prognosis of this syndrome may be excellent irrespective of hemodynamic instability.

Expression analysis of rice VQ genes in response to biotic and abiotic stresses

WRKY transcription factors are encoded by a large gene superfamily with a broad range of roles in plants. Proteins containing a short VQ (FxxxVQxLTG) motif have been recently shown to interact with WRKY transcription factors, implying that AtVQ proteins are important in the plant defense responses in Arabidopsis, either as positive or negative cofactors of WRKY transcription factors. Thirty-nine Oryza sativa genes containing the VQ motif (OsVQs) were identified and the genome structures of OsVQ proteins were characterized through genome-wide analysis in rice. Also, phylogenetic tree analysis was performed with the VQ domain of Arabidopsis and rice. The expression patterns of these OsVQ genes in plants under several stress treatments were assessed, specifically, following infection with the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), treatment with abscisic acid (ABA), or exposure to drought. The cellular localization of a few OsVQ proteins was examined using rice protoplast system. Based on our results, we suggest that OsVQ proteins function as important co-regulators during the plant defense response to biotic and abiotic stresses.

Routine Screening for Abdominal Aortic Aneurysm during Clinical Transthoracic Echocardiography in a Korean Population

Background: An abdominal aortic aneurysm (AAA) is potentially fatal when ruptured. Whereas the transthoracic echocardiography (TTE) protocol does not routinely include examination of the infrarenal abdominal aorta, the protocol is performed quickly and easily for AAA screening. Aim: The aim of this study was to evaluate the clinical utility of the protocol for AAA screening during TTE in a Korean population referred for clinical TTE. Methods: All of the patients who were scheduled for TTE were enrolled in the study. At the end of TTE protocol, the abdominal aorta was evaluated at the level below the renal artery origin. Results: A total of 6,267 patients were screened, and the abdominal aortas were visualized in 79% (4,939 patients) of patients screened. AAA was diagnosed in 27 patients, 23 of whom were male. The mean age of AAA patients was 66.5 years old, and 81% of AAA patients were over 60 years old. The presence of AAA was associated with male gender and older age, as well as with hypertension and smoking. Of the 27 patients, 11 patients (0.2% of the study population) did not have a history of AAA screening and were newly diagnosed by TTE. Conclusions: Screening of AAA during TTE is easy and feasible. Even though the prevalence of AAA in patients is very low, detection of asymptomatic AAA may save lives. Therefore, opportunistic examination of the abdominal aorta during routine TTE, which involves little time and cost, would appear to be effective, at least in patients over 60 years of age, especially in men. (Echocardiography 2010;27:1182‐1187)

Assessment of Left Ventricular Mass in Hypertrophic Cardiomyopathy by Real-Time Three-Dimensional Echocardiography Using Single-Beat Capture Image

BACKGROUND Left ventricular (LV) mass is an important prognostic indicator in hypertrophic cardiomyopathy. Although LV mass can be easily calculated using conventional echocardiography, it is based on geometric assumptions and has inherent limitations in asymmetric left ventricles. Real-time three-dimensional echocardiographic (RT3DE) imaging with single-beat capture provides an opportunity for the accurate estimation of LV mass. The aim of this study was to validate this new technique for LV mass measurement in patients with hypertrophic cardiomyopathy. METHODS Sixty-nine patients with adequate two-dimensional (2D) and three-dimensional echocardiographic image quality underwent cardiac magnetic resonance (CMR) imaging and echocardiography on the same day. Real-time three-dimensional echocardiographic images were acquired using an Acuson SC2000 system, and CMR-determined LV mass was considered the reference standard. Left ventricular mass was derived using the formula of the American Society of Echocardiography (M-mode mass), the 2D-based truncated ellipsoid method (2D mass), and the RT3DE technique (RT3DE mass). RESULTS The mean time for RT3DE analysis was 5.85 ± 1.81 min. Intraclass correlation analysis showed a close relationship between RT3DE and CMR LV mass (r = 0.86, P < .0001). However, LV mass by the M-mode or 2D technique showed a smaller intraclass correlation coefficient compared with CMR-determined mass (r = 0.48, P = .01, and r = 0.71, P < .001, respectively). Bland-Altman analysis showed reasonable limits of agreement between LV mass by RT3DE imaging and by CMR, with a smaller positive bias (19.5 g [9.1%]) compared with that by the M-mode and 2D methods (-35.1 g [-20.2%] and 30.6 g [17.6%], respectively). CONCLUSIONS RT3DE measurement of LV mass using the single-beat capture technique is practical and more accurate than 2D or M-mode LV mass in patients with hypertrophic cardiomyopathy.

Comparative measurement of aortic root by transthoracic echocardiography in normal Korean population based on two different guidelines

BackgroundAortic root size is an important parameter in vascular diseases and can be easily assessed by transthoracic echocardiography. However, measurements values may vary according to cardiac cycle and the definition used for edge. This study aimed to define normal values according to the measurement method specified by two different guidelines to determine the influence of the different methods on echocardiographic measurements.MethodsHealthy Korean adults were enrolled. The aortic root diameters were measured twice at four levels (aortic annulus, sinuses of Valsalva, sinotubular junction, and ascending aorta) by the 2005 American Society of Echocardiography (ASE) guidelines (measured from leading edge to leading edge during diastole) and the 2010 ASE pediatric guidelines (measured from inner edge to inner edge during systole).ResultsOne hundred twelve subjects aged 20–69 years were enrolled. The aortic diameters (cm) determine by the aforementioned two guidelines showed significant difference. Measurements were larger in 2005 ASE guideline at aortic annuls, sinuses of Valsalva, and sinotubular junction level, but smaller at ascending aortic level with 2-3mm of differences. Intraobserver variability was similarly good, but interobserver variability was slightly higher than intraobserver variability in both measurement methods. BSA and age was most important determinant for aortic root size.ConclusionsThe measurement method of aortic root can affect the echocardiographic result. The measurement method should be noted when assessing clinical significance of aortic root measurement.

A high loading dose of clopidogrel reduces myocardial infarct size in patients undergoing primary percutaneous coronary intervention: A magnetic resonance imaging study

BACKGROUND We sought to determine whether a 600-mg loading dose of clopidogrel reduces myocardial infarct size compared with a 300-mg dose using contrast-enhanced magnetic resonance imaging in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). METHODS In 198 patients undergoing primary PCI for STEMI, contrast-enhanced magnetic resonance imaging was performed a median of 7 days after the index event. Infarct size was measured on delayed-enhancement imaging, and area at risk (AAR) was quantified on T2-weighted images. RESULTS Baseline characteristics were not significantly different between the 600-mg clopidogrel loading group (n = 117) and the 300-mg group (n = 81). The median infarct size was significantly smaller in the 600-mg group than in the 300-mg group (17.3% [8.9%-26.2%] vs 21.7% [12.9%-30.0%], P = .03). Myocardial salvage index ([AAR - infarct size] × 100/AAR) was greater in the 600-mg group than in the 300-mg group (47.7 [33.7-60.9] vs 32.0 [23.6-51.5], P < .01). Patients in the 600-mg group also had a significantly lower extent of microvascular obstruction and smaller number of segments with >75% of infarct transmurality than did those in the 300-mg group. After propensity score matching, the 600-mg group had smaller infarct size and greater myocardial salvage index compared with the 300-mg group. In multivariate analysis, the use of a 600-mg clopidogrel loading dose significantly reduced the risk of a large infarct (odds ratio 0.53, 95% CI 0.29-0.98, P = .04). CONCLUSIONS In patients undergoing primary PCI for STEMI, a 600-mg loading dose of clopidogrel reduced myocardial infarct size and improved myocardial salvage compared with a 300-mg loading dose.

Early detection of cardiac involvement in Miyoshi myopathy: 2D strain echocardiography and late gadolinium enhancement cardiovascular magnetic resonance

BackgroundMiyoshi myopathy (MM) is an autosomal recessive distal myopathy characterized by early adult onset. Cardiomyopathy is a major clinical manifestation in other muscular dystrophies and an important prognostic factor. Although dysferlin is highly expressed in cardiac muscle, the effect of dysferlin deficiency in cardiac muscle has not been studied. We hypothesized that early myocardial dysfunction could be detected by 2D strain echocardiography and late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR).MethodFive consecutive MM patients (3 male) in whom we detected the DYSF gene mutation and age-matched healthy control subjects were included. None of the patients had history of cardiac disease or signs and symptoms of overt heart failure. Patients were studied using 2D strain echocardiography and CMR, with 2D strain being obtained using the Automated Function Imaging technique.ResultsAll patients had preserved left ventricular systolic function. However, segmental Peak Systolic Longitudinal Strain (PSLS) was decreased in 3 patients. Global PSLS was significantly lower in patients with MM than in control subjects (p = 0.005). Basal anterior septum, basal inferior septum, mid anterior, and mid inferior septum PSLS were significantly lower in patients with MM than in control subjects (P < 0.0001, < 0.0001, 0.038 and 0.003, respectively). Four patients showed fibrosis by LGE. The reduced PSLS lesion detected by 2D strain tended to be in the same area as that which showed fibrosis by LGE.ConclusionsPatients with MM showed subclinical involvement of the heart. 2D strain and LGE are sensitive methods for detecting myocardial dysfunction prior to the development of cardiovascular symptoms. The prognostic significance of these findings warrants further longitudinal follow-up.

Correlation between levels of N-terminal pro-B-type natriuretic peptide and degrees of heart failure.

Background The N-terminal fragment of pro Brain Natriuretic Peptide (NT-pro BNP) is a neuro-hormone synthesized in the cardiac ventricles in response to increased wall tension. The purpose of this study was to assess the correlation between the NT-pro BNP levels and the New York Heart Association function class (NYHA Fc) of dyspnea and echocardiographic findings for the patients who visited our cardiology departments. Methods From October, 2002 to April, 2003, serum NT-pro BNP levels were measured in 348 patients who visited the Samsung Medical Center and the Jong Koo Lee Heart Clinic. Results The NT-pro BNP levels were increased with the progression of NYHA Fc of dyspnea (p<0.001 by ANOVA), the increase in the systolic left ventricular internal dimension (p<0.05), and the decrease in the ejection fraction (p<0.01). For the NYHA Fc I patients, the NT-pro BNP levels were positively correlated with age (p<0.001) and left atrial size (p<0.001). For the patients with ischemic heart disease, the NT-pro BNP levels were also positively correlated with the NYHA Fc (p<0.001 by ANOVA). The NT-pro BNP levels were increased with the increase in the systolic (p<0.001) and diastolic pressure (p=0.017), the left ventricular internal dimension as well as the decrease in the ejection fraction (p<0.001). The area under the receiver operating characteristic (ROC) curve for the NT-pro BNP levels was 0.994 (95% confidence interval, 0.979-0.999), and the most reliable cut-off level for the NT-pro BNP was 293.6 pg/mL. Conclusion The NT-pro BNP levels were positively correlated with the NYHA Fc of dyspnea and the systolic dysfunction for the patients who visited our cardiology departments. A 300 pg/mL value for the NT-pro BNP cut-off point appears to be a sensitive level to differentiate dyspnea originating from an ailing heart or not for the patients who visited our cardiology departments.