Biventricular function in preterm infants with patent ductus arteriosus ligation: A three-dimensional echocardiographic study.

BACKGROUND: The detailed hemodynamics after patent ductus arteriosus (PDA) ligation in preterm infants remain unknown. We aimed to clarify the effect of surgical ligation on left ventricular (LV) and right ventricular (RV) volume and function. METHODS: Echocardiography was performed in 41 preterm infants (median gestational age: 25 weeks) before and after PDA ligation. Global longitudinal strain was determined using three-dimensional speckle-tracking echocardiography. These values were compared with those in 36 preterm infants without PDA (non-PDA). RESULTS: Preoperatively, the PDA group had greater end-diastolic volume (EDV) and cardiac output (CO) in both ventricles, a higher LV ejection fraction (LVEF) (53% vs 44%) and LV global longitudinal strain, and a lower RVEF (47% vs 52%) than the non-PDA group. At 4-8 h postoperatively, the two groups had a similar LVEDV and RVEDV. However, the PDA group had a lower EF and CO in both ventricles than the non-PDA group. At 24-48 h postoperatively, the RVEF was increased, but the LVEF remained decreased, and LVCO was increased. CONCLUSIONS: PDA induces biventricular loading and functional abnormalities in preterm infants, and they dramatically change after surgery. Three-dimensional echocardiography may be beneficial to understand the status of both ventricles. IMPACT: Preterm infants are at high risk of hemodynamic compromise following a sudden change in loading conditions after PDA ligation. Three-dimensional echocardiography enables quantitative and serial evaluation of ventricular function and volume in preterm infants with PDA. PDA induces biventricular loading and functional abnormalities in preterm infants, and they dramatically change after surgery.

[Left Main Trunk Orifice Reconstruction Using Aortic flap and Autologous Pulmonary Arterial Patch for Severe Left Main Trunk Stenosis After Arterial Switch Operation].

A 6-year-old boy with left main trunk (LMT) stenosis, who had undergone arterial switch operation (ASO) for transposition of the great arteries( TGA) before 6 years, underwent LMT orifice reconstruction. Coronary angiography showed severe stenosis of LMT, already when he was hospitalized with heart failure after 3 months of ASO. He was stable with oral treatment, therefore we performed the LMT reconstruction, before starting school, in terms of the risk of coronary ischemic event. We reconstructed the LMT ostium using an aortic flap and autologous pulmonary arterial patch. The postoperative computed tomography showed neither stenosis nor kinking at the repair site of LMT. He remains asymptomatic for over 6 months. We have reported that this method is effective to repair coronary artery anomalies (CAAs), since using an aortic flap. We could form a coronary artery floor, which is affixed to the aortic wall. This method allows us to change the coronary orifice position and the angle, so it is very useful method not for only CAAs, but also for coronary stenosis after ASO.

Perioperative junctional ectopic tachycardia associated with congenital heart disease: risk factors and appropriate interventions.

The risk factors and the appropriate interventions for perioperative junctional ectopic tachycardia (JET) in congenital heart disease (CHD) surgery have not been sufficiently investigated despite the severity of this complication. This study aimed to examine the risk factors and interventions for perioperative JET. From 2013 to 2020, 1062 surgeries for CHD (median patient age: 4.3 years, range 0.0-53.0) with or without a cardiopulmonary bypass (CPB) were performed at Hokkaido University, Japan. We investigated the correlation between perioperative JET morbidity factors, such as age, genetic background, CPB/aortic cross-clamp (ACC) time, use of inotropes and dexmedetomidine, STAT score, and laboratory indices. The efficacy of JET therapies was also evaluated. Of the 1062 patients, 86 (8.1%) developed JET. The 30-day mortality was significantly high in JET groups (7% vs. 0.8%). The independent risk factors for JET included heterotaxy syndrome [odds ratio (OR) 4.83; 95% confidence interval (CI) 2.18-10.07], ACC time exceeding 90 min (OR 1.90; CI 1.27-2.39), and the use of 3 or more inotropes (OR 4.11; CI 3.02-5.60). The combination of anti-arrhythmic drugs and a temporary pacemaker was the most effective therapy for intractable JET. Perioperative JET after CHD surgery remains a common cause of mortality. Inotrope use was a risk factor for developing JET overall surgery risk. In short ACC surgeries, heterotaxy syndrome could increase the risk of JET, which could develop even without inotrope use in long ACC surgeries. It is crucial not to delay the treatment in cases with unstable hemodynamics caused by this arrhythmia. It is recommended to reduce numbers not dose of inotropes.

Cosmetic and shoulder functional outcomes in posterolateral minithoracotomy atrial septal defect closure: A retrospective study.

BACKGROUND AND AIM: Transcatheter device closure has become the first treatment option for atrial septal defects (ASD). Surgical ASD closure, although still implemented, is cosmetically inferior to transcatheter closure. This study aimed to evaluate the feasibility as well as short- and long-term clinical outcomes of the right posterolateral minithoracotomy approach for surgical ASD closure. METHODS: In total, 102 consecutive patients underwent posterolateral minithoracotomy for ASD between January 2014 and December 2021 at our center. Early surgical outcomes, cosmetic findings, and skin perception were evaluated over 1 year of postoperative follow-up using a self-satisfaction survey (1: very good, 2: good, 3: normal, 4: not good, 5: bad), Cavendish score, and shoulder joint function (angles of flexion, extension, and abduction). RESULTS: No patient required conversion to median sternotomy. Only one patient required reoperation due to bleeding. Postoperative echocardiography revealed no residual shunt at discharge in all patients. The mean follow-up period was 3.7 years (range: 0.3-7.1 years), during which the questionnaire was answered by 69 of 98 patients who were evaluated after more than 1 year. The mean self-satisfaction survey scores for cosmetic findings and skin perception were 1.3 ± 0.6 and 1.2 ± 0.5, respectively. The Cavendish score was under Grade 1 in all patients. Shoulder flexion and abduction were normal at 180° in all patients, except one, while extension was normal at 50° in all patients, except three. CONCLUSIONS: Our procedure achieved not only good early surgical outcomes but also excellent long-term cosmetic and shoulder function results.

[Midterm Outcomes of Pulmonary Valve Leaflet Augmentation using Fresh Autologous Pericardium for Transannular Patch Repair of Tetralogy of Fallot].

BACKGROUND: Although valve sparing (VS) for patients with smaller pulmonary valves has been increasing, transannular patch repair( TAP) accounts for more than half of the total tetralogy of Fallot corrections worldwide. We use fresh autologous pericardial patches to perform a modified TAP procedure with pulmonary valve leaflet augmentation as proposed by Sung et al. We aimed to explore the early and midterm outcomes of this procedure. METHODS: We retrospectively reviewed 37 patients( group TAP:12;group VS:25) who underwent total tetralogy of Fallot corrections from April 2018 to December 2021. RESULTS: No midterm mortality was observed at a median observation period of 20.4 months in both groups. The midterm rates of freedom from moderate or more pulmonary regurgitation( PR) were 64.2 % and 21.4% in group TAP and 100% and 100% in group VS at 1 and 3 years, respectively( p<0.001). The midterm rates of freedom from pulmonary stenosis reintervention were 100% and 100% in group TAP and 96% and 96% in group VS at 1 and 3 years, respectively( p=0.51). CONCLUSIONS: TAP showed acceptable midterm survival and reintervention rate. Longer follow-up is essential considering the significantly higher PR in the postoperative period in group TAP.

Optimization of prediction methods for risk assessment of pathogenic germline variants in the Japanese population.

Predicting pathogenic germline variants (PGVs) in breast cancer patients is important for selecting optimal therapeutics and implementing risk reduction strategies. However, PGV risk factors and the performance of prediction methods in the Japanese population remain unclear. We investigated clinicopathological risk factors using the Tyrer-Cuzick (TC) breast cancer risk evaluation tool to predict BRCA PGVs in unselected Japanese breast cancer patients (n = 1,995). Eleven breast cancer susceptibility genes were analyzed using target-capture sequencing in a previous study; the PGV prevalence in BRCA1, BRCA2, and PALB2 was 0.75%, 3.1%, and 0.45%, respectively. Significant associations were found between the presence of BRCA PGVs and early disease onset, number of familial cancer cases (up to third-degree relatives), triple-negative breast cancer patients under the age of 60, and ovarian cancer history (all P < .0001). In total, 816 patients (40.9%) satisfied the National Comprehensive Cancer Network (NCCN) guidelines for recommending multigene testing. The sensitivity and specificity of the NCCN criteria for discriminating PGV carriers from noncarriers were 71.3% and 60.7%, respectively. The TC model showed good discrimination for predicting BRCA PGVs (area under the curve, 0.75; 95% confidence interval, 0.69-0.81). Furthermore, use of the TC model with an optimized cutoff of TC score ≥0.16% in addition to the NCCN guidelines improved the predictive efficiency for high-risk groups (sensitivity, 77.2%; specificity, 54.8%; about 11 genes). Given the influence of ethnic differences on prediction, we consider that further studies are warranted to elucidate the role of environmental and genetic factors for realizing precise prediction.

Apex rotation as a risk factor for total anomalous pulmonary connection repair in single ventricle.

BACKGROUND: The high incidence of postoperative pulmonary venous obstruction (PVO) is a major mortality-associated concern in patients with right atrial isomerism and extracardiac total anomalous pulmonary venous connection (TAPVC). We evaluated new anatomical risk factors for reducing the space behind the heart after TAPVC repair. METHODS: Eighteen patients who underwent TAPVC repair between 2014 and 2020 were enrolled. Sutureless technique was used in 12 patients and conventional repair in six patients. The angle between the line perpendicular to the vertebral body and that from the vertebral body to the apex was defined as the "vertebral-apex angle (V-A angle)." The ratio of postoperative and preoperative angles, indicating the apex's lateral rotation, was compared between patients with and without PVO. RESULTS: The median (interquartile range) age and body weight at repair were 102 (79-176) days and 3.8 (2.6-4.8) kg, respectively. The 1-year survival rate was 83% (median follow-up, 29 [11-36] months). PVO occurred in seven patients (39%), who showed an obstruction of one or two branches in the apex side. The postoperative V-A angle (46° [45°-50°] vs. 36° [29°-38°], p = 0.001) and the ratio of postoperative and preoperative V-A angles (1.27 [1.24-1.42] vs. 1.03 [0.98-1.07], p = 0.001) were significantly higher in the PVO group than in the non-PVO group. The cut-off values of the postoperative V-A angle and ratio were 41° and 1.17, respectively. CONCLUSION: A postoperative rotation of the heart apex into the ipsilateral thorax was a risk factor for branch PVO after TAPVC repair.

Successful surgical management of cyanotic congenital heart disease complicated by pulmonary aspergillosis.

Pulmonary aspergillosis associated with cyanotic congenital heart disease is a rare condition, which is known to have a poor prognosis. We report a case of a 21-year-old woman with truncus arteriosus and major aortopulmonary collateral arteries who underwent primary Rastelli procedure after thoracoscopic lobectomy for the management of progressive pulmonary aspergillosis.

[Modified Carpentier Technique is Useful Method for Tricuspid Regurgitation in Hypoplastic Left Heart Syndrome].

Management of tricuspid regurgitation( TR) before right ventricular dysfunction is critical in patients with hypoplastic left heart syndrome (HLHS);however, appropriate tricuspid valvuloplasty (TVP) is challenging. We report a TVP technique for TR in a 4-year-old girl with HLHS, who had undergone Norwood operation, bidirectional cavopulmonary shunt, and TVP. Preoperative echocardiography revealed the etiology of TR as anterior leaflet prolapse, annulus dilatation, and relative tethering of the septal leaflet. We performed surgical reconstruction of the anterior leaflet with artificial chordae. Before annuloplasty, the posterior leaflet and a part of the septal leaflet were detached from the annulus with a 1 mm margin using the Key-Reed technique. Furthermore, the posterior leaflet was slid to augment the septal leaflet. We managed to regulate the TR by enlarging the septal leaflet, thus increasing the coaptation zone. We believe that this technique will be useful for TR with annulus dilatation in HLHS.

Forns Index is a predictor of cardiopulmonary bypass time and outcomes in Fontan conversion.

Recent reports suggested that cardiopulmonary bypass (CPB) time is one of the risk factors for postoperative complications after Fontan conversion. Although Fontan conversion may be performed for the patients with hepatic fibrosis after initial Fontan procedure, there is no predictive indicator regarding the liver function associated with hemostasis which can affects CPB time. Thirty-one patients who underwent Fontan conversion using the same surgical procedure (extracardiac conduit conversion with right atrium exclusion) were enrolled. In multivariate analyses including age at Fontan conversion, interval from initial Fontan to conversion, hemodynamic data such as right atrial pressure, ventricular end-diastolic pressure, and cardiac index, hepatic data such as platelet count, prothrombin time international normalized ratios, serum total bilirubin, hyaluronic acid levels, five known indices for hepatic fibrosis (Forns Index, APRI, FIB4, FibroIndex, and MELD-XI), and liver stiffness measured by ultrasound elastography, only the Forns Index remained independently associated with the CPB time (P < 0.01) and blood transfusions (plasma transfusions and platelet concentrations: P < 0.01 for both). The cutoff level for Forns Index to predict the prolonged CPB time (exceeding 240 min) was 4.85 by receiver-operating characteristic curve (area under the curve 0.823, sensitivity 76.9%, and specificity 72.2%). Three patients with Forns Index > 7.0 had poor outcomes with long CPB time and massive blood transfusions in contrast with the other 28 patients. In conclusion, Forns Index could serve as a practical predictor of CPB time and is associated with blood transfusion volume in Fontan conversion.

Mechanical properties of a new thermally deformable mitral valve annuloplasty ring and its effects on the mitral valve.

Ideally, an annuloplasty ring's shape should be changed intraoperatively if mitral valve repair is unsuccessful because of a short coaptation length or systolic anterior motion. Several post-implantation adjustable rings have been developed, but they are not freely deformable and are unsuitable for asymmetric repair of the valvular annulus. We developed a novel thermally deformable mitral annuloplasty ring to address these problems and assessed the ring's mechanical properties and its effect on the mitral valve anatomy. This ring was made of polycaprolactone. Tensile and bending tests were performed to evaluate the ring's mechanical properties. The ratio of the transverse and septal-lateral length was determined as 4:3. Using 10 pig hearts, we measured the post-deformation coaptation length and minimum distance from the coaptation to the ventricular septum, which is a factor of abnormal systolic anterior motion of the mitral valve. In the mechanical tests, the ring's yield point was greater than the deformation force of the annulus in humans. In pigs with deformation from "4:3" to "4:2", the coaptation length was significantly increased in each mitral valve part. In pigs with deformation from "4:3" to "4:4", the minimum distance from the coaptation to the ventricular septum was significantly increased. Asymmetrical ring deformation increased the coaptation length only at the deformed area. In conclusion, this new thermally deformable mitral annuloplasty ring could be "order-made" to effectively change the coaptation length in all parts of the mitral valve and the distance from the coaptation to septum post-deformation via intraoperative heating.

Re-do mitral valve replacement for a bioprosthetic valve with central transvalvular leakage in a patient with ischemic cardiomyopathy: a case report.

Transvalvular leakage (TVL) of a prosthetic heart valve is not negligible regurgitant flow in patients with critically low contractile function. Although the opening function of prosthetic valves has been reported, its closing function is not well understood. A man in his 70 s had a history of mitral valve replacement (MVR) with a Magna Mitral® valve for ischemic mitral valve regurgitation. He presented with dyspnea 2 years postoperatively. Echocardiography showed moderate TVL. The pulmonary capillary wedge pressure and cardiac index were 37 mmHg and 1.65 L/min/m2, respectively. Because we considered his TVL relevant, we performed re-do MVR with a mechanical valve and papillary muscle approximation and suspension ("papillary muscle tugging approximation"). His cardiac function improved postoperatively; he was discharged with New York Heart Association class I. For MVR in patients with critically low contractile function, prosthetic valves, such as mechanical valves, with small TVL are recommended.

Surgery for Left Ventricular Outflow Tract Obstruction with a Relatively Thin Interventricular Septum.

BACKGROUND: To examine the results of myectomy and mitral valve surgery for systolic anterior motion (SAM) of the mitral valve and left ventricular outflow tract obstruction (LVOTO) with a relatively thin interventricular septum. METHODS: The subjects were 12 patients with SAM and LVOTO. Eight had hypertrophic obstructive cardiomyopathy (HOCM) with a mean interventricular septal thickness of 16 mm. Three had sigmoid septum and one had an unknown etiology. For HOCM, isolated extended myectomy was performed when mitral regurgitation was mild (n = 1) and extended myectomy plus mitral valve surgery was performed when mitral regurgitation was more than mild (n = 4) or primary valve etiologies existed (n = 3). Myectomy was performed for the three cases with sigmoid septum. Myectomy plus height reduction of the posterior mitral leaflet was performed for the one case with the unknown etiology of SAM. RESULTS: In the patients with HOCM, the maximum LVOT pressure gradient significantly decreased from 140 ± 18 to 16 ± 6 and 3 ± 3 mm Hg, while mitral regurgitation significantly decreased from 2.3 ± 0.5 to 0.5 ± 0.3 and 0.4 ± 0.2 at pre-op, early post-op, and last follow-up (3 ± 1 years), respectively. In the other etiologies, the maximum LVOT pressure gradient changed from 56 ± 15 to 25 ± 15 and 5 ± 4 mm Hg; mitral regurgitation changed from 2.0 ± 0.6 to 1.3 ± 0.3 and 1.3 ± 0.8, at pre-op, early post-op, and the last follow-up (3 ± 2 years), respectively. CONCLUSION: Myectomy with mitral valve surgery is an option for SAM and LVOTO in patients with a relatively thin interventricular septum.

Anticoagulation management during cardiopulmonary bypass in patients with antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is a complex autoimmune disease often related to systemic lupus erythematosus. Although adequate anticoagulation is important for APS patients during cardiopulmonary bypass, clotting tests can be potentially misleading due to antiphospholipid antibodies. We performed cardiac surgery safely in two APS patients under anticoagulation monitoring determined using preoperative heparin titration. We performed heparin titration for activated clotting time to determine the appropriate heparin concentration during cardiac surgery. We changed the targeted heparin concentration considering each patient's thrombotic risks: 3 U/ml of heparin for a normal-risk APS patient and 5 U/ml for a high-risk APS patient with a history of antiphospholipid-antibody-associated thrombocytopenia. A higher targeted heparin concentration might be necessary for patients with high thrombotic risks.

[Surgical Options for Refractory Heart Failure Patients with Non-ischemic Dilated Cardiomyopathy].

Surgical strategy for non-ischemic dilated cardiomyopathy (NIDCM) is currently controversial. Subjects were 20 patients who underwent left ventriculoplasty(LVP) from 2006 to 2013 and 6 patients who underwent papillary muscle tugging approximation (PMTA) after 2015. PMTA is a new trans-mitral approach combined with valve replacement without left ventriculotomy. Another group of patients( n=14)who were registered for heart transplantation( HTx) after 2013 was also analyzed for left ventricular assist device(LVAD) free survival. Mw( slope in the preload recruitable stroke work relationship) calculated by single beat technique using echocardiography was employed as a load-independent cardiac functional parameter. The baseline characteristics and Mw were not different between the LVP and PMTA groups. One-year survival was significantly lower in the LVP group(53%)than in the PMTA group(100%)[log-rank:p=0.024]. In the HTx group, early LVAD implantation was necessary in the patients who had low Mw(<20)at the time of registration. In conclusion, PMTA would be one option for NIDCM patients( non-HTx candidates) with severe mitral regurgitation. Early LVAD implantation might be predicted in HTx candidates with low Mw(<20).

Left-Ventricular Plication Reduces Wall Stress and Cardiomyocyte Hypertrophy in a Rat Model of Ischemic Cardiomyopathy.

BACKGROUND: The indications of left-ventricular plication (LVP) are controversial, although several studies have reported favorable outcomes in heart failure patients. The aim of this study was to assess left-ventricular (LV) wall stress and myocardial remodeling after LVP in a rat model of myocardial infarction (MI). METHODS: Sixteen rats underwent LVP by excluding the LV anterior wall scar 4 weeks after ligation of the left anterior descending artery. After 4 weeks, LV wall stress was assessed using transthoracic echocardiography and an LV catheter. Gene expression of the wall stress markers, atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP), were evaluated via reverse transcription polymerase chain reaction. Cardiomyocyte area and myocardial fibrosis were also examined through histological examinations. These parameters were compared to those in 16 rats that underwent coronary artery ligation but not LVP. RESULTS: We noted that the LV end-diastolic dimension was smaller (9.9 ± 0.3 vs. 11.2 ± 0.2 mm, p < 0.05) and fractional shortening was greater (25 ± 2 vs. 15 ± 1%, p < 0.05) in LVP rats than in sham rats. Moreover, systolic wall stress was lower in LVP rats (71 ± 7 vs. 111 ± 9 × 103 dyn/cm2, p < 0.05). Myocardial ANF and BNP expression levels were lower in LVP rats (2.6 ± 0.3 vs. 4.4 ± 0.5 and 1.0 ± 0.1 vs. 1.5 ± 0.2 arbitrary units, respectively; p < 0.05). Cardiomyocyte area was significantly decreased in LVP rats (556 ± 15 vs. 670 ± 28 µm2, p = 0.003) and was correlated with LV wall stress (r = 0.669, p = 0.002). The reduction in myocardial fibrosis after LVP was not significant. CONCLUSION: LVP reduced LV wall stress and cardiomyocyte hypertrophy in a rat model of MI.

Interventricular septal hematoma following repair of a ventricular septal defect.

An interventricular septal hematoma is a rare complication after patch closure of a ventricular septal defect (VSD). We describe three cases of interventricular septal hematomas following patch VSD and discuss their management.

Changes of Cerebral Oxygenation in Sequential Glenn and Fontan Procedures in the Same Children.

Recently, it is common to perform the Fontan procedure after the Glenn procedure as surgical repair for the univentricular heart. How the brain oxygen saturation (rSO2) values change with the cardiac restoration and the process of growth during these procedures in individual children remains unknown. In this study, we retrospectively studied rSO2 data as well as the perioperative clinical records of 30 children who underwent both Glenn and Fontan procedures by the same surgeon in the same institute. The rSO2 was measured at the beginning and end of each procedure with an INVOS 5100C. Cerebral perfusion pressure was calculated by subtracting central venous pressure from mean arterial pressure. Arterial oxygen saturation (SaO2) and the hemoglobin concentration were obtained as candidates affecting rSO2 changes at the start and the end of both procedures. The rSO2 increased during the Glenn procedure, but this increase was slight and insignificant. On the other hand, the rSO2 significantly increased during the Fontan procedure. Significant increases in SaO2 were observed only between the beginning and end of the Fontan procedure. Correlation coefficients determined by linear regression analysis were more than 0.5 between rSO2 and SaO2 in both procedures. Multiple linear regression analysis showed that SaO2 was the key determinant of the rSO2. The rSO2 increases step by step from the Glenn to the Fontan procedure in the same patient. Within each procedure, SaO2 is the key determinant of the rSO2. The significance of rSO2 monitoring in these procedures should be further evaluated.

What We Can Learn from Cases of Synchronous Acute Mesenteric Obstruction and Nonocclusive Mesenteric Ischemia: How to Reduce the Acute Mesenteric Ischemia-Related Mortality Rate.

Although the survival rate of patients with ischemic heart disease has recently increased, it remains unknown why the mortality rate of acute mesenteric ischemia (AMI) remains high. Here, we report a possible method of improving the survival rate of patients with AMI obtained through 2 cases of simultaneous acute mesenteric obstruction (AMO) and nonocclusive mesenteric ischemia (NOMI). Case 1 was a 74-year-old woman with atrial fibrillation, hypertension, and dyslipidemia as underlying diseases who developed NOMI immediately after undergoing SMA thrombolysis. Case 2 was a 69-year-old man with atrial fibrillation, hypertension, chronic heart failure, chronic renal failure, and old myocardial infarction who was diagnosed with SMA occlusion complicated by NOMI on the basis of abdominal angiography findings during the first visit. Cure was achieved by thrombolytic therapy, resection of the necrotic intestine, and continuous intra-arterial and/or intravenous injection of prostaglandin E1 (PGE1) in case 1 and by resection of the necrotic intestine and continuous intra-arterial and/or intravenous injection of PGE1 in case 2. AMO and NOMI have many background similarities (e.g., atherosclerosis, hypertension, and ischemic heart disease), making their coexistence very likely. However, no case of AMO plus NOMI has been reported until now. It is highly probable that concomitant NOMI is overlooked in cases of AMO. When managing AMO, NOMI should be considered as a complication, which may lower the patient's potential risk of developing NOMI and contribute to improved prognosis of both AMO and AMI.

The significance of the analysis on scalographic pattern for detecting malfunctioning bileaflet valve with the wavelet analysis.

The authors developed the wavelet analysis system which can detect the splitting of bileaflet mechanical heart valve (BLV) into two spikes on the scalogram, and reported that either consecutive single spike or the split behavior can detect malfunctioning BLV (MBV). The latest study on 12 BLVs suggested that the comparison between two spike areas showed higher potential to detect MBV than the split behavior. The aim of the current study is to review 226 files of BLV sound and to select the suitable scalographic property to differentiate the function of BLV with the split. Eight of 30 MBV files showed consecutive single spike, and the rest of 22 MBV files showed two spikes. Two spike areas can be compared by the following three ratios; the anterior spike area/posterior spike area (Aa/La), its reverse ratio (Pa/Aa) and the smaller spike area/the larger spike ratio (Sa/La). Therefore, the current study compared those three ratios to pursue the suitable ratio to compare two spike areas and its sensitivity to differentiate valve function by the ROC analysis. As a result, the Sa/La was suitable for comparing two spike areas, and only this ratio showed high accuracy to differentiate the function of BVL with the split, and its cutoff value was <0.665. Conclusively, the key for detecting MBV was either consecutive single spike or the mean of Sa/La < 0.665. However, this cutoff point is still tentative due to small number of malfunctioning valves, and other key might be available in future.