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Biomedical subjects

Yong Jin Kim

Publications and source records attributed to Yong Jin Kim.

18 recordsLinked to original sources
PubMed2005

Mid-term follow-up of neoaortic regurgitation after the arterial switch operation for transposition of the great arteries.

OBJECTIVE: The aim of this study was to determine the outcome of the neoaortic valve after the arterial switch operation for transposition of the great arteries. METHODS: A retrospective review of arterial switch operations that were performed during the period from 1991 to 2003 was conducted. We followed patients with echocardiography. When regurgitation of the neoaortic valve was observed we analyzed the risk factors. RESULTS: One hundred and three patients underwent a successful arterial switch operation. Eighty-one males and 22 females participated in the study. Follow-up period was 77+/-42 months. The age and body weight at the time of the arterial switch operation were 1.4+/-2.8 months and 3.8+/-1.0 kg, respectively. Preoperative pulmonary valve regurgitation was found in six patients (two patients had grade I and four patients had grade II). In the postoperative echocardiography, 52 patients demonstrated neoaortic valve regurgitation (26 patients had grade I, 25 patients had grade II, and 1 patient had grade III). At the last follow-up visit, 61 patients demonstrated neoaortic regurgitation (18 patients had grade I, 37 patients had grade II, 5 patients had grade III, and 1 patient had grade IV). Neoaortic valve regurgitation increased progressively with follow-up (p-value<0.01). The size discrepancy between the aorta and the pulmonary artery was correlated with neoaortic valve regurgitation (p-value=0.02). The age and body surface area, relationship of the great arteries, coronary arterial pattern, pulmonary artery banding, use of trap-door technique, myocardial ischemic time, use of total circulatory arrest, and existence of ventricular septal defect were not significant risk factors. CONCLUSIONS: Neoaortic valve regurgitation progressed after the arterial switch operation. The degree of regurgitation was more severe in patients with a size discrepancy between the aorta and the pulmonary artery preoperatively.

Aortic Valve↗
PubMed2005

Tetrahaloindate(III)-based ionic liquids in the coupling reaction of carbon dioxide and epoxides to generate cyclic carbonates: H-bonding and mechanistic studies.

The microwave reactions of InX3 with [Q]Y produce a series of tetrahaloindate(III)-based ionic liquids (ILs) with a general formula of [Q][InX3Y] (Q = imidazolium, phosphonium, ammonium, and pyridinium; X = Cl, Br, I; Y = Cl, Br). The reaction of CO2 with a variety of epoxides has been examined in the presence of these ILs wherein tetrahaloindate(III)-based ILs are found to exhibit high catalytic activities and evidence is presented that supports the significant role of H-bonding interactions in the [Q][InX3Y]-catalyzed coupling reactions. The effects of various parameters such as temperature, pressure, and molar ratio of propylene oxide to catalyst have been investigated, and the plausible reaction mechanism based on the 1H and 13C NMR studies is presented for the formation of propylene carbonate.

Journal Article↗
PubMed2005

Usefulness of Doppler assessment of pulmonary vein and left atrial appendage flow following pulmonary vein isolation of chronic atrial fibrillation in predicting recovery of left atrial function.

Atrial fibrillation (AF) is a widespread condition that causes significant morbidity and mortality. Recently, pulmonary venous (PV) isolation using radiofrequency ablation has been used successfully to exclude the pulmonary venous ostia, resulting in correction of AF. Further, miniaturized high-frequency ultrasound phased-array transducers currently provide Doppler and 2-dimensional imaging during the ablation procedure. We examined atrial function and its determinants using intracardiac echocardiography before and after PV isolation in 45 patients who had chronic AF (56 +/- 11 years old). PV, left atrial (LA) appendage, and mitral and tricuspid flows were recorded. Recovery of booster pump function (defined by the presence of mitral inflow A wave, LA appendage a-wave, and PV A-reversal wave velocities >10 cm/s) was observed in 39 of 45 patients (86.6%). PV flow systolic wave before and after ablation correlated with the degree of LA booster pump function after PV isolation. An early systolic PV flow peak velocity >57.47 cm/s predicted "good" LA booster pump function recovery with 96% specificity. Diastolic LA appendage emptying in AF correlated (p <0.001) and predicted good LA booster pump function with 92% specificity for velocities >46.4 cm/s. Thus, monitoring LA function during PV isolation for chronic AF is feasible. Most patients recovered LA booster pump function immediately after PV isolation, and the degree of recovery correlated with LA reservoir function. Preserved reservoir function during AF is predictive of satisfactory recovery of booster pump function after PV isolation.

Aged↗
PubMed2005

Fontan conversion with arrhythmia surgery.

OBJECTIVE: Hemodynamic abnormalities and refractory atrial arrhythmias in patients late after the Fontan operation result in significant morbidity and mortality. We reviewed our experience with Fontan conversion and concomitant arrhythmia surgery. METHODS: Between January 1996 and February 2004, 16 patients underwent Fontan conversion and arrhythmia surgery. Mean age at the initial Fontan operation was 5.1+/-3.5 (range: 2-15) years and mean age at Fontan conversion was 17.0+/-5.8 (range: 6-30). The initial Fontan operations were atriopulmonary connections in 14 patients, extracardiac lateral tunnel in 1, and intracardiac lateral tunnel in 1. The types of arrhythmia included atrial flutter in 10 patients and atrial fibrillation in 3. Fontan conversion operation was performed with intracardiac lateral tunnel in 5 patients and extracardiac conduit in 11. Arrhythmia surgery included isthmus cryoablation in 10 patients and right-sided maze in 3. RESULTS: There has been no mortality. At Fontan conversion operation, 7 patients required permanent pacemaker. All patients have improved to New York Heart Association class I or II. With a mean follow-up of 26.9+/-30.6 (range:1-87) months, 16 patients had sinus rhythm, 2 patients had transient atrial flutter which was well controlled, and 2 patients required permanent pacemaker during follow-up. CONCLUSIONS: Fontan conversion with concomitant arrhythmia surgery and permanent pacemaker placement is safe, improves New York Heart Association functional class, and has a low incidence of recurrent arrhythmias. In most patients, concomitant permanent pacemakers are needed.

Adolescent↗
PubMed2004

Determinant of left atrial dilation in patients with hypertrophic cardiomyopathy: a real-time 3-dimensional echocardiographic study.

To identify the determinants of left atrial (LA) dilation for patients with hypertrophic obstructive cardiomyopathy (HOCM), first we validated LA volume determination by real-time 3-dimensional echocardiography using magnetic resonance imaging in patients. Subsequently, real-time 3-dimensional echocardiography and 2-dimensional Doppler echocardiography were performed in 60 patients with HOCM and in 17 age-matched control subjects. LA volumes and left ventricular (LV) filling pressures were higher for patients with HOCM than in control subjects. By stepwise multilinear regression analysis, LV end-diastolic pressure, resting LV outflow tract pressure gradient, and LV wall thickness were significant determinants of LA dilation. However, tau, -dP/dt, LV stiffness, provokable pressure gradient, and mitral regurgitation did not have any independent relationship with LA volumes. Therefore, it is concluded that LA volume can be accurately determined by real-time 3-dimensional echocardiography; and LA dilation in patients with HOCM is related to LV filling pressure, LV outflow tract pressure gradient, and LV wall thickness.

Atrial Function, Left↗
PubMed2004

Repair of transposition of the great arteries, ventricular septal defect and left ventricular outflow tract obstruction.

OBJECTIVES: This study was undertaken to compare the outcomes of the Lecompte procedure and Rastelli repair in the transposition of the great arteries (TGA) with ventricular septal defect (VSD) and left ventricular outflow tract obstruction (LVOTO) and to determine the risk factors associated with unfavorable events. METHODS: Over a 12-year period (April 1990-October 2002), 35 patients underwent complete repair for TGA, VSD, and LVOTO. Twenty-five patients (71%) underwent the Lecompte modification, and mean age and weight were 23.4+/-18.2 months and 10.2+/-3.0 kg. Ten patients (29%) underwent the Rastelli operation, and mean age and weight were 39.1+/-36.1 months and 13.8+/-6.8 kg. RESULTS: One early death (3%) occurred after the Lecompte procedure and no late death. The mean follow-up was 5.9+/-3.8 years. Eight patients in the Rastelli group (80%) underwent a late reoperation for obstruction of the extracardiac conduit, and in four of these patients, a reoperation for LVOTO was concomitantly required. Reoperation was also required in six patients of the Lecompte group (25%); five for right ventricular outflow tract obstruction (RVOTO) including one for LVOTO and two for VSD leakage, and one for mitral regurgitation and left pulmonary artery stenosis. The interval prior to reoperation ranged from 1.6 to 11.1 years, with a mean of 5.7+/-3.1 years. The actuarial figures for freedom from reoperation at 5 and 10 years were 40.0+/-15.5 and 26.7+/-15.0% after the Rastelli operation and 95.7+/-4.3 and 63.5+/-12.6% after the Lecompte procedure (P = 0.02). Multivariate analysis by Cox regression analysis revealed that the risk factors of RVOTO were a younger age at operation, the Rastelli operation, and ductus ligation during the operation. CONCLUSIONS: The Lecompte procedure and Rastelli repair provide satisfactory early and late results. However, substantial late morbidity is more associated with conduit obstruction, and LVOTO in Rastelli repair rather than Lecompte procedure.

Abnormalities, Multiple↗
PubMed2004

Management of congenital tracheal stenosis.

OBJECTIVES: Congenital tracheal stenosis is a rare disease. Various methods for treatment exist but there is still much debate as to the appropriate surgical procedure. We present our surgical experiences of patch tracheoplasty and slide tracheoplasty as viable methods for the treatment of congenital tracheal stenosis. METHODS: From 1994 to 2002, 13 patients were diagnosed with congenital tracheal stenosis. Eight patients (7 symptomatic and 1 asymptomatic) had their stenosis corrected, three by means of pericardial patch tracheoplasty, four by slide tracheoplasty, and one by resection and anastomosis. Concomitant operations were performed on six patients to treat congenital cardiovascular disease. Five patients showing no significant symptoms did not undergo tracheal surgery and received only cardiac procedures. A retrospective review of the hospital course, complications, and long-term results was conducted. RESULTS: Among the patch tracheoplasty group, every patient suffered from granulation tissue formation. One patient died of respiratory acidosis and one was hospitalized due to recurrent granulation tissue, which required frequent bronchoscopy. The third patient from this group is free of all symptoms. Among the slide tracheoplasty group, one patient died of anastomosis disruption. The three remaining patients are alive and well. The one patient who received resection and anastomosis is alive without symptoms. CONCLUSIONS: Surgical repair of long-segment congenital tracheal stenosis exhibited high mortality and morbidity rates. Every patient that underwent pericardial patch tracheoplasty suffered from troublesome granulation tissue. As slide tracheoplasty provided relatively good results in the short and mid-term follow-up periods, it seems to be a preferred method for the treatment of long-segment congenital tracheal stenosis.

Female↗
PubMed2004

Elastic properties of the ascending aorta in young children after successful coarctoplasty in infancy.

BACKGROUND: Based on the hypothesis that vascular dysfunction in the ascending aorta can cause morbidity, we undertook this study on the elastic properties of ascending aorta and left ventricular (LV) function in young children who received coarctoplasty in early infancy. METHODS: Blood pressures (BP) in the right arm and ascending aortic internal diameters determined by M-mode ultrasound at rest and after exercise were measured in 25 patients (mean age, 6.4+/-3 years) and 22 control subjects (mean age, 5.8+/-2.4 years). Ascending aortic stiffness index and distensibility were calculated using BP measurements and ascending aortic internal diameters. In addition, LV parameters (systolic and diastolic function, mass index) were evaluated. RESULTS: Compared with control subjects, patients had increased stiffness index (at rest: 4.87+/-1.94 versus 3.57+/-1.19, P=0.021; after exercise: 4.33+/-1.91 versus 3.2+/-1.26, P=0.034) and decreased distensibility (at rest: 6.90+/-3.15 versus 8.72+/-2.77, P=0.02; after exercise: 5.69+/-2.39 versus 7.88+/-3.44 cm2 dyn(-1) 10(-6), P=0.023). BP and LV parameters showed no consistent differences between the two groups. In patients, distensibility was significantly correlated with systolic BP (at rest: P=0.008; after exercise: P=0.014) and pulse pressure (at rest: P=0.013; after exercise: P=0.001). CONCLUSIONS: This study suggests that vasculopathy of ascending aorta is possible in some young children despite early correction. However, long-term tracking study is needed to clarify the significance of the study.

Aorta↗
PubMed2004

Combination of pulsed-wave Doppler and real-time three-dimensional color Doppler echocardiography for quantifying the stroke volume in the left ventricular outflow tract.

Real-time three-dimensional (3-D) color Doppler echocardiography (RT3D) is capable of quantifying flow. However, low temporal resolution limits its application to stroke volume (SV) measurements. The aim of the present study was, therefore, to develop a reliable method to quantify SV. In animal experiments, cross-sectional images of the LV outflow tract were selected from the RT3D data to calculate peak flow rates (Q(p3D)). Conventional pulsed-wave (PW) Doppler was performed to measure the velocity-time integral (VTI) and the peak velocity (V(p)). By assuming that the flow is proportional to the velocity temporal waveform, SV was calculated as alpha x Q(p3D) x VTI/V(p), where alpha is a temporal correction factor. There was an excellent correlation between the reference flow meter and RT3D SV (mean difference = -1. 3 mL, y = 1. 05 x -2. 5, r = 0. 94, p < 0. 01). The new method allowed accurate SV estimations without any geometric assumptions of the spatial velocity distributions.

Animals↗
PubMed2003

Surgical results of patients with a functional single ventricle.

OBJECTIVE: Overall mortality of the patients with a functional single ventricle is still high, though excellent mid- and long-term results of the modified Fontan procedure have been reported. This study assessed the factors that affect the surgical outcomes mainly in the pre-Fontan stage and performed long-term survival analysis. METHODS: Between January 1988 and December 2000, 405 patients with a functional single ventricle underwent surgical interventions and were followed up until June 2001. The mean follow-up period was 74.5+/-69.4 months and 95% of the patients were followed up completely. Their median age was 2.5 months at the time of shunt or pulmonary artery banding (PAB), 8.6 months at BCPS, and 28.6 months at the Fontan operation. The variables of the anatomical lesions with single ventricle physiology, combined abnormalities, surgical pathways leading to the Fontan stage, age at operation, study periods, and type of the Fontan procedure were analyzed. The role of BCPS in the long-term results was evaluated. RESULTS: Overall survival after birth was 60.1+/-2.8% at 10 years. In multivariate analysis, complete atrioventricular septal defect-typed lesion, pulmonary venous obstruction, total anomalous pulmonary venous connection, and interruption of aortic arch were risk factors for long-term survival, while pulmonary stenosis was demonstrated as a favorable prognostic factor. In this study, there was no significant survival difference between the early and late study period. Actuarial mortality in the pre-Fontan stage was 41.3% in the non-BCPS group and 16.3% in the BCPS group (P<0.001). The 10-year survival rates of the populations in staged and primary Fontan groups were not significantly different (P=0.24). The long-term survival rate of the atriopulmonary Fontan group was significantly lower than that of lateral tunnel Fontan (60.3+/-6.3% vs. 86.8+/-3.1% at 10 years, P=0.0001). CONCLUSION: This study revealed that the overall survival was disappointing and there were still problems that need to be solved in the pre-Fontan stage to improve the overall survival. The role of BCPS was not to contribute to the longer survival after Fontan operation, but to lower mortality in the pre-Fontan stage, which can offer a higher probability to proceed to the Fontan procedure successfully.

Child↗
PubMed2003

Real-time three-dimensional color doppler evaluation of the flow convergence zone for quantification of mitral regurgitation: Validation experimental animal study and initial clinical experience.

BACKGROUND: Pitfalls of the flow convergence (FC) method, including 2-dimensional imaging of the 3-dimensional (3D) geometry of the FC surface, can lead to erroneous quantification of mitral regurgitation (MR). This limitation may be mitigated by the use of real-time 3D color Doppler echocardiography (CE). Our objective was to validate a real-time 3D navigation method for MR quantification. METHODS: In 12 sheep with surgically induced chronic MR, 37 different hemodynamic conditions were studied with real-time 3DCE. Using real-time 3D navigation, the radius of the largest hemispherical FC zone was located and measured. MR volume was quantified according to the FC method after observing the shape of FC in 3D space. Aortic and mitral electromagnetic flow probes and meters were balanced against each other to determine reference MR volume. As an initial clinical application study, 22 patients with chronic MR were also studied with this real-time 3DCE-FC method. Left ventricular (LV) outflow tract automated cardiac flow measurement (Toshiba Corp, Tokyo, Japan) and real-time 3D LV stroke volume were used to quantify the reference MR volume (MR volume = 3DLV stroke volume - automated cardiac flow measurement). RESULTS: In the sheep model, a good correlation and agreement was seen between MR volume by real-time 3DCE and electromagnetic (y = 0.77x + 1.48, r = 0.87, P <.001, delta = -0.91 +/- 2.65 mL). In patients, real-time 3DCE-derived MR volume also showed a good correlation and agreement with the reference method (y = 0.89x - 0.38, r = 0.93, P <.001, delta = -4.8 +/- 7.6 mL). CONCLUSIONS: real-time 3DCE can capture the entire FC image, permitting geometrical recognition of the FC zone geometry and reliable MR quantification.

Adult↗
PubMed2002

Left ventricular outflow tract mean systolic acceleration as a surrogate for the slope of the left ventricular end-systolic pressure-volume relationship.

OBJECTIVE: The goal of this study was to analyze left ventricular outflow tract systolic acceleration (LVOT(Acc)) during alterations in left ventricular (LV) contractility and LV filling. BACKGROUND: Most indexes described to quantify LV systolic function, such as LV ejection fraction and cardiac output, are dependent on loading conditions. METHODS: In 18 sheep (4 normal, 6 with aortic regurgitation, and 8 with old myocardial infarction), blood flow velocities through the LVOT were recorded using conventional pulsed Doppler. The LVOT(Acc) was calculated as the aortic peak velocity divided by the time to peak flow; LVOT(Acc) was compared with LV maximal elastance (E(m)) acquired by conductance catheter under different loading conditions, including volume and pressure overload during an acute coronary occlusion (n = 10). In addition, a clinically validated lumped-parameter numerical model of the cardiovascular system was used to support our findings. RESULTS: Left ventricular E(m) and LVOT(Acc) decreased during ischemia (1.67 +/- 0.67 mm Hg.ml(-1) before vs. 0.93 +/- 0.41 mm Hg.ml(-1) during acute coronary occlusion [p < 0.05] and 7.9 +/- 3.1 m.s(-2) before vs. 4.4 +/- 1.0 m.s(-2) during coronary occlusion [p < 0.05], respectively). Left ventricular outflow tract systolic acceleration showed a strong linear correlation with LV E(m) (y = 3.84x + 1.87, r = 0.85, p < 0.001). Similar findings were obtained with the numerical modeling, which demonstrated a strong correlation between predicted and actual LV E(m) (predicted = 0.98 [actual] -0.01, r = 0.86). By analysis of variance, there was no statistically significant difference in LVOT(Acc) under different loading conditions. CONCLUSIONS: For a variety of hemodynamic conditions, LVOT(Acc) was linearly related to the LV contractility index LV E(m) and was independent of loading conditions. These findings were consistent with numerical modeling. Thus, this Doppler index may serve as a good noninvasive index of LV contractility.

Acceleration↗
PubMed2002

Outcomes of medically treated patients with aortic intramural hematoma.

PURPOSE: Aortic intramural hematoma has been considered a precursor of aortic dissection, and the same treatment strategy, usually involving surgery, has been applied to both conditions. However, the outcomes of patients with aortic intramural hematoma who are treated medically, including the remodeling process that occurs after an acute event, are not known. SUBJECT AND METHODS: A total of 124 patients with acute aortic intramural hematoma (41 in the proximal aorta and 83 in the distal aorta) was enrolled from five institutions in South Korea. Patients received medical treatment without surgery. A follow-up imaging study was performed in 105 patients. RESULTS: Pericardial (59% [n = 24] vs. 11% [n = 9], P <0.004) and pleural effusions (63% [n = 26] vs. 45% [n = 37], P = 0.05) were more common in patients with the proximal type than in those with the distal type. In-hospital mortality was somewhat higher with proximal hematomas (7% [n = 3 deaths] vs. 1% [n = 1 death], P = 0.11). A follow-up imaging study in 36 patients with proximal hematomas confirmed resorption of the hematoma in 24 patients (67%) and development of aortic dissection in 9 (25%). Resorption was confirmed in 54 (78%) of the 69 patients with distal hematomas who underwent follow-up imaging; localized aortic dissection developed in 11 (16%) of these patients. The 3-year survival rate was 78% in the proximal type and 87% in the distal type (P = 0.10). CONCLUSION: Patients with aortic intramural hematoma had a high rate of resorption with medical treatment regardless of the affected site. Further investigation is necessary to determine the optimal treatment strategy and timing of surgical intervention, especially for patients with proximal hematomas.

Acute Disease↗
PubMed2002

Impact of left ventricular outflow tract area on systolic outflow velocity in hypertrophic cardiomyopathy: a real-time three-dimensional echocardiographic study.

OBJECTIVES: The aim of this study was to use real-time three-dimensional echocardiography (3DE) to investigate the quantitative relation between minimal left ventricular (LV) outflow tract area (A(LVOT)) and maximal LV outflow tract (LVOT) velocity in patients with hypertrophic obstructive cardiomyopathy (HCM). BACKGROUND: In patients with HCM, LVOT velocity should change inversely with minimal A(LVOT) unless LVOT obstruction reduces the pumping capacity of the ventricle. METHODS: A total of 25 patients with HCM with systolic anterior motion (SAM) of the mitral valve leaflets underwent real-time 3DE. The smallest A(LVOT) during systole was measured using anatomically oriented two-dimensional "C-planes" within the pyramidal 3DE volume. Maximal velocity across LVOT was evaluated by two-dimensional Doppler echocardiography (2DE). For comparison with 3DE A(LVOT), the SAM-septal distance was determined by 2DE. RESULTS: Real-time 3DE provided unique information about the dynamic SAM-septal relation during systole, with A(LVOT) ranging from 0.6 to 5.2 cm(2) (mean: 2.2 +/- 1.4 cm(2)). Maximal velocity (v) correlated inversely with A(LVOT) (v = 496 A(LVOT)(-0.80), r = -0.95, p < 0.001), but the exponent (-0.80) was significantly different from -1.0 (95% confidence interval: -0.67 to -0.92), indicating a significant impact of small A(LVOT) on the peak LVOT flow rate. By comparison, the best correlation between velocity and 2DE SAM-septal distance was significantly (p < 0.01) poorer at -0.83, indicating the superiority of 3DE for assessing A(LVOT). CONCLUSIONS: Three-dimensional echocardiography-measured A(LVOT) provides an assessment of HCM geometry that is superior to 2DE methods. These data indicate that the peak LVOT flow rate appears to be significantly decreased by reduced A(LVOT). Real-time 3DE is a potentially valuable clinical tool for assessing patients with HCM.

Adult↗
PubMed2002

Midterm result of leaflet extension technique in aortic regurgitation.

OBJECTIVES: Aortic valve leaflet extension using glutaraldehyde-fixed autopericardium in aortic regurgitation (AR) is technically demanding, and it is not a popular procedure among surgeons. This study evaluates the effectiveness and clinical feasibility of the leaflet extension technique as a treatment modality for AR. MATERIALS AND METHODS: From March 1995 to March 2001, 34 consecutive patients underwent the leaflet extension technique. The mean age of the 26 men and eight women was 31.0+/-14.3 years (range 16-68). They were all diagnosed with pure aortic valve regurgitation, and nine (27.3%) had associated mitral valvular heart diseases. Accurate measurement of the leaflet free margins was performed with a pair of compasses before leaflet extension. Glutaraldehyde-fixed autopericardium was designed according to the free margin lengths. Leaflet extension was performed in three aortic leaflets for 29 patients but only one leaflet was extended in the remaining four. The nine patients with associated mitral valvular heart disease also underwent mitral valvuloplasty. Mean cardiopulmonary bypass time and ischemic time in 25 isolated AR group were 128.7+/-26.5min (range 70--180) and 101.5+/-25.5min (range 41-150), respectively. RESULTS: There was no incidence of in-hospital mortality. Immediate postoperative echocardiography revealed grade II AR in one, grade I AR in ten and no AR in the remaining 23 patients. Mean follow-up duration was 49.6+/-18.8 months (range 4.1-77.1). Echocardiographic AR grades during follow-up were grade II in 13, grade I in 11 and no AR in eight. The remaining two patients underwent reoperation, one aortic valve replacement because of subacute bacterial endocarditis that occurred 7 months after leaflet extension, and the other Ross operation because of the dehiscence of the valvuloplasty suture site that developed 4 months later (AR associated with Behcet's disease). There was one case of mortality due to malignant mesothelioma 4 years after aortic valvuloplasty. The cumulative survival rate was 94.1% at 5 years. Freedom from reoperation was 93.8% at 1 year and after. CONCLUSIONS: The leaflet extension technique is an acceptable surgical treatment modality for AR and its clinical results were confirmed in this study to be very good. A careful long-term follow-up study will be necessary to evaluate the long-term durability of the glutaraldehyde-preserved autologous pericardium as a leaflet tissue.

Adult↗
PubMed2002

Pulmonary venous flow determinants of left atrial pressure under different loading conditions in a chronic animal model with mitral regurgitation.

BACKGROUND: The aim of our study was to quantitatively compare the changes and correlations between pulmonary venous flow variables and mean left atrial pressure (mLAP) under different loading conditions in animals with chronic mitral regurgitation (MR) and without MR. METHODS: A total of 85 hemodynamic conditions were studied in 22 sheep, 12 without MR as control (NO-MR group) and 10 with MR (MR group). We obtained pulmonary venous flow systolic velocity (Sv) and diastolic velocity (Dv), Sv and Dv time integrals, their ratios (Sv/Dv and Sv/Dv time integral), mLAP, left ventricular end-diastolic pressure, and MR stroke volume. We also measured left atrial a, x, v, and y pressures and calculated the difference between v and y pressures. RESULTS: Average MR stroke volume was 10.6 +/- 4.3 mL/beat. There were good correlations between Sv (r = -0.64 and r = -0.59, P <.01), Sv/Dv (r = -0.62 and r = -0.74, P <.01), and mLAP in the MR and NO-MR groups, respectively. Correlations were also observed between Dv time integral (r = 0.61 and r = 0.57, P <.01) and left ventricular end-diastolic pressure in the MR and NO-MR groups. In velocity variables, Sv (r = -0.79, P <.001) was the best predictor of mLAP in both groups. The sensitivity and specificity of Sv = 0 in predicting mLAP 15 mm Hg or greater were 86% and 85%, respectively. CONCLUSION: Pulmonary venous flow variables correlated well with mLAP under altered loading conditions in the MR and NO-MR groups. They may be applied clinically as substitutes for invasively acquired indexes of mLAP to assess left atrial and left ventricular functional status.

Animals↗
PubMedDate not supplied

Neuroprotective effect of KR-31378, a novel potassium channel activator, on spinal cord ischemic injury in rabbits.

Neurologic deficits after the surgical repair of thoracic and thoracoabdominal aortic disease are devastating complications. Recently, pharmacologic preconditioning with potassium channel openers was reported to protect the spinal cord against neurologic injury in a model of spinal cord ischemia. A novel benzopyran derivative with an N-cyanoguanidine group, KR-31378, has been synthesized as a new therapeutic agent against ischemic injury. In the present study, we evaluated the protective effects of KR-31378 on spinal cord ischemic injury and compared its neuroprotective activities and hemodynamic stabilities with those of diazoxide. Thirty-four New Zealand white rabbits were randomly divided into four groups: ischemia group (n = 10, 25 min of aortic cross-clamping without any intervention), diazoxide group (n = 8, diazoxide [5 mg/kg] intravenously 15 min before the 25-min cross-clamping), KR20 group (n = 8, KR-31378 [20 mg/kg] intravenously 30 min before the 25-min cross-clamping), and the KR50 group (n = 8, KR-31378 [50 mg/kg] intravenously 30 min before the 25-min cross-clamping). Neurologic functions were evaluated for 72 h postoperatively using modified Tarlov's scores. All rabbits were sacrificed for histopathologic observations after finally scoring neurologic function. All rabbits but three survived. The rest were completely evaluated 72 h postoperatively. Unlike diazoxide-treated rabbits, KR-31378-treated rabbits showed relatively stable hemodynamics. Tarlov's score outcomes showed a marked improvement in the diazoxide group, in the KR20 group, and in the KR50 group compared to the ischemia group (p = .005, .002, and .001, respectively). However, Tarlov's scores in the KR50 group were not significantly different from those of the diazoxide group. Histopathologic data were not significantly different between the groups, but the degree of degenerative change in motor neurons showed a significant correlation with Tarlov's scores 3 days postoperatively (gamma = -.378, p = .036). Thus, the administration of KR-31378 before the aortic cross-clamping resulted in a significant improvement in neurologic outcome with stable hemodynamics in this rabbit model.

Animals↗