• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.52-61
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• 1994

Background : The demand for refinement in noninvasive and quantitative assessment of left ventricular (LV) function is increasing. Purpose : To assess normal values of left ventricular functional parameters during both systole and diastole by scintigraphic method using computerized triple-head gamma camera and to evaluate correlations between these parameters. Methods : ECG gated blood pool scan with $^{99m}Tc$-Human serum albumin was performed in 94 normal Korean subjects. Ejection fraction (EF), systolic parameters [peak emptying rate (PER), average emptying rate (AER), time to peak emptying rate (TPER)], and diastolic parameters [peak filling rate (PFR), average filling rate (AFR), time to peak filling rate (TPFR)] were obtained by analysis of LV time-activity curve, the correlation of these parameters to the age and sex, and the correlation between these parameters were evaluated. Results : 1) Mean value of ejection fraction in study subjects was $59.6{\pm}5.25%$ and showed no significant correlation to age (r=-0.08) and sex but showed most pronounced correlation to PFR (r=0.46, p<0.001), PER (r=0.41, p<0.001), AFR (r=0.34, p<0.001) and AER (r=0.28, p<0.01). 2) Mean values of systolic parameters were as follows: $PER=3.22{\pm}0.50$ end-diastolic volume/sec, $AER=2.22{\pm}0.45$ end-diastolic volume/sec, $TPER=103.5{\pm}29.30$ msec. They showed no significant correlation to age and sex. 3) Mean values of diastolic parameters were as follows: $PFR=2.71{\pm}0.51$ end-diastolic volume/sec, $AFR=1.83{\pm}0.44$ end-diastolic volume/sec, $TPFR=132.1{\pm}33.45$ msec. They showed strong correlation to age (r=0.70, -0.64, 0.37, p<0.001). Conclusions : Left ventricular functional parameters in normal Korean subjects were obtained reliably by computerized scintigraphic method and may be applied to the evaluation of cardiac function in diseased patients.

• Clinical and Experimental Pediatrics
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• v.49 no.5
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• pp.539-544
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• 2006

Purpose : The purpose of this study was to determine whether N-terminal fragment of B-type natriuretic peptide(NT-proBNP) may be used to differentiate acute Kawasaki disease(KD) from other clinically similar diseases. Methods : Using electrochemiluminescence immunoassay, NT-proBNP concentrations were measured in the acute phase within 10 days after the onset of KD(n=58) and in the convalescent phase, 60 to 81 days after the onset(n=51), and also in patients with acute febrile disease as a control(n=34). Echocardiography was performed to detect pericardial effusion(PE) and coronary artery lesions(CAL), and to measure the left ventricular dimension at diastole(LVIDd) and ejection fraction(LVEF). The cutoff value of NT-proBNP for separating KD from other diseases was determined. Results : NT-proBNP concentration in the acute phases of KD was significantly higher than that in the control group($1,501.6{\pm}2,132.6$ vs. $139.0{\pm}88.8pg/mL$, P<0.0001). In KD patients, NT-proBNP was elevated in the acute phase and was lowered in the convalescent phase($1,466.0{\pm}2,173.2$ vs. $117.5{\pm}95.5pg/mL$, P<0.0001). The cutoff value of 260 pg/mL discriminated KD patients from other patients, with a sensitivity of 93 percent and a specificity of 88 percent. The NT-proBNP was higher in patients with PE(n=17) compared with those without PE(n=41)($1,784.2{\pm}1,903.1$ vs. $1,384.4{\pm}2,232.6pg/mL$, P=0.52). Comparison of NT-proBNP could not be done between patients with CAL and those without, owing to a small number of patients with CAL(n=3). There was no correlation between NT-proBNP and LVEF index(r=0.104, P=0.46) or LVIDd index(r=0.171, P=0.22). Conclusion : NT-proBNP increases in the acute phase of KD and decreases to within normal range in the convalescent phase. NT-proBNP >260 pg/mL may be highly suggestive of acute KD. NT-proBNP may be used as a diagnostic tool for KD.

• Investigative Magnetic Resonance Imaging
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• v.18 no.4
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• pp.314-322
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• 2014

Purpose: Diastolic dysfunction is a common problem in patients with hypertrophic cardiomyopathy (HCM). The purpose of this study was to assess the role of MRI in the assessment of diastolic function using mitral valve and pulmonary vein flow velocities in HCM patients. Methods and Results: Phase-contrast MRI (mitral valve and pulmonary vein) and transthoracic echocardiography was successfully performed for 59 HCM patients (44 men and 15 women; mean age, 51 years). Forty-nine patients had a diastolic dysfunction; grade 1 (n = 20), grade 2 (n = 27), and grade 3 (n = 2) using echocardiography, and ten patients had normal diastolic function. The transmitral inflow parameters (E, A, and E/A ratios) obtained by MRI showed positive correlation with the same parameters measured by echocardiography (Pearson's r values were 0.47, 0.60, and 0.75 for E, A, E/A, respectively, all P < 0.001). With the flow information of the pulmonary vein from cardiac MRI, pseudo-normalized pattern (n = 8) could be distinguished from true normal filling pattern (n = 17), and the diastolic function grades by cardiac MRI showed moderate agreement with those of echocardiography (kappa value = 0.45, P < 0.001). Conclusions: Assessment of left ventricle diastolic function is feasible using phase-contrast MRI in HCM patients. Analysis of pulmonary vein flow velocity on MRI is useful for differentiating pseudo-normal from normal diastolic function in HCM patients.

• The Korean Journal of Medicine
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• v.93 no.6
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• pp.538-547
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• 2018

Background/Aims: The impact of left ventricular (LV) diastolic function and filling pressure on clinical outcomes in young patients with acute myocardial infarction (AMI) has been poorly studied. Therefore, the aim of this study was to investigate the impact of LV diastolic function and LV filling pressure on major adverse cardiac events (MACEs) in young patients with AMI. Methods: A total of 200 young patients (males < 45 year, females < 55 year) with AMI were divided into two groups according to the diastolic function; normal (n = 46, $39.5{\pm}5.3$ years) versus abnormal (n = 154, $43.5{\pm}5.1$ years). Results: Despite regional wall motion abnormalities, normal LV diastolic function was not uncommon in young AMI patients (23.0%). During the 40 months of clinical follow-up, MACEs developed in 26 patients (13.0%); 14 re-percutaneous coronary intervention (7.0%), 8 recurrent MI (4.0%), and 4 deaths (2.0%). MACEs did not differ between the normal and abnormal diastolic function group (13.6% vs. 10.9%, p = 0.810), but MACEs were significantly higher in the high LV filling pressure group than the normal LV filling pressure group (36.8% vs. 10.5%, p < 0.001). On multivariate analysis, high LV filling pressure was an independent predictor of MACEs (hazard ratio 3.022, 95% confidence interval 1.200-7.612, p = 0.019). Conclusions: This study suggested that measurement of the LV filling pressure (E/e' ratio) would be useful in the risk stratification of young patients with AMI. However, it would be necessary to monitor this category of patient more carefully.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.703-709
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• 2008

Background: Diagnosis and treatment are often successful in the setting of cardiac myxomas. However, cardiac myxomas can lead to catastrophic complications, due to intracardiac obstruction and embolism preoperatively, and can recur postoperatively. Material and Method: We retrospectively reviewed the clinical characteristics, surgical treatment, and recurrence data of 85 patients who underwent cardiac myxoma surgery at Asan Medical Center between November 1994 and June 2007. We analyzed the morphologic characteristics of 58 patients with left atrial myxomas and determined the development of functional mitral valve stenosis and systemic embolism through reviewing the results of preoperative echo-cardiograms to find potential preoperative risk factors. Result: Twenty-seven (31.8%) patients were men, and 58 (68.2%) were women. The mean patient age was $54.5{\pm}14.3$ years. Preoperative symptoms included obstructive symptoms in 41 (48.2%) patients, signs of embolism in 19 (22.4%), constitutional symptoms in 8 (9.4%), and no symptoms in 19 (20.0%). Among the 58 patients with left atrial myxomas, the mean maximal tumor diameter was $4.3{\pm}1.8$ (range $1.1{\sim}8\;cm$)cm. Twenty-six (44.8%) patients had a prolapsing type, defined as a tumor mobile enough to move down. to the mitral. annular plane during diastole, and 32 (55.2%) had villous type, defined as a tumor consisting of multiple fine villous extensions on the surface. Twelve (20.7%) patients had severe functional mitral valve stenosis, and 15 (25.9%) had systemic embolism preoperatively. The incidence of severe functional mitral valve stenosis was significantly higher in patients with the prolapsing type than in those with the non-prolapsing type (p=0.001). The mean maximal tumor diameter in patients with severe functional mitral valve stenosis was $5.1{\pm}1.0\;cm$, significantly larger than that seen in patients without severe functional mitral valve stenosis (p=0.041). The incidence of systemic embolism was significantly higher in patients with the villous type than in those with the smooth type (p=0.006). Postoperative complications were noted in 6 (7.1%) patients, and early mortality was noted in 1 (1.2%). The mean postoperative follow-up duration was $36.2{\pm}37.5$ months, with recurrence reported in 2(2.4%) patients during the follow-up period. The disease free interval were 48, 12 months, respectively. Conclusion: Surgical treatment for cardiac myxomas was performed safely, and long-term prognosis was good. In patients with left atrial myxoma, close attention should be maintained and surgery should be performed promptly in those of prolapsing type, those with large maximal diameter in order to prevent severe functional mitral valve stenosis, and those of villous type in order to prevent systemic embolism. Echocardiography should be followed serially in order to detect recurrence.