[An Anastomotic Aneurysm Thirty Years After Open Surgery of the Descending Thoracic Aorta:Report of a Case].

An 86-year-old man was hospitalized urgently to our department because of his worsening hemoptysis. He had undergone open thoracic aortic grafting for the Stanford type B chronic aortic dissecting aneurysm 30 years earlier. Contrast enhanced computed tomography (CT) revealed the distal anastomotic aneurysm, leakage of the contrast medium around the distal anastomotic site. We urgently performed thoracic endovascular aneurysm repair( TEVAR) for the distal anastomotic aneurysm. TEVAR was done under local anesthesia because of his poor respiratory condition due to hemoptysis. He recovered well without hemoptysis. Patients after open aortic surgery are expected to survive longer. Thus, special attention should be paid to the occurrence of anastomotic aneurysms.

[Coronary Artery Bypass Grafting in an Elderly Patient with Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery].

We report a case of a 73-year-old woman who was diagnosed with anomalous origin of the left coronary artery(LCA) from the pulmonary artery(ALCAPA) by coronary angiography. Drug stress myocardial perfusion scintigraphy demonstrated myocardial ischemia in the left anterior descending coronary artery (LAD) region. She underwent single coronary artery bypass grafting to LAD using left internal thoracic artery (LITA) and direct closure of the origin of the anomalous LCA. Postoperative coronary catheterization revealed a patent graft showing no residual shunt from the pulmonary artery into the left coronary artery. Myocardial scintigraphy proved improvement of the ischemia. In general, once ALCAPA is diagnosed, early surgical intervention is recommended. However, since there are few reports regarding surgical treatment for ALCAPA in elderly patients, the optimal treatment strategy is not completely established. Therefore careful long-term follow-up is mandatory.

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.

The scalographic pattern of Morlet continuous wavelet transform can differentiate bileaflet valve function.

The authors have discussed the significance of the Morlet continuous wavelet transform of bileaflet mechanical heart valve (BLMHV) sound for detecting its malfunction: consecutive single patterns on the scalogram alway suggested its malfunction, whereas the tandem pattern with two steepled figures was demonstrated in both normal and malfunctioning valves. Therefore, authors have tried to distinguish this pattern between them by manually calculated multiple scalographic parameters. Although only the sum of wavelet coefficients (SWC) is supposed to be closer to valve sound property than other parameters, its calculation was not available in the original wavelet application. Therefore, the application was customized in the current study to semi-automatically calculate the SWC ratio between two figures for classifying the scalographic pattern of malfunctioning valves, and its efficacy to distinguish valve function was compared to other parameters. Among 155 BLMHVs, 6 valves with consecutive single patterns (type-I) and other 6 with two similar needle-like narrow figures (type-II) were confirmed to be a malfunction by fluoroscopic examination, whereas 14 malfunctioning valves with the tandem pattern which showed a great difference between two figure sizes (type-III) were distinguished from 129 normal valves by the cutoff point of the SWC ratio < 0.482 with the highest AUC (0.960) compared to other parameters by the ROC analysis.

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.

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.

Blood flow characteristics of the bilateral internal thoracic artery: implications of optimal graft configuration for coronary artery bypass grafting to maximize blood supply.

PURPOSE: There is controversy regarding which internal thoracic artery (ITA) should be anastomosed to the left anterior descending artery (LAD). Here, we propose an optimal graft design based on measurement of blood flow in the ITA. METHODS: Sixty-one patients (53 men, median age 68 [62-75] years) undergoing first elective coronary artery bypass grafting were enrolled. Fifty-seven left ITAs (LITAs) and 28 right ITAs (RITAs) were harvested in either a semi-skeletonized manner using a harmonic scalpel covered with papaverine-soaked gauze (group-A, n = 45) or a fully skeletonized manner using electrocautery with intraluminal papaverine injection (group-B, n = 41). Free flow of 33 ITAs was measured after pharmacological dilatation and in situ ITA-LAD flow was measured in 59 patients by transit-time flowmetry. RESULTS: RITA and LITA free flow were 147.0 [87.8-213.0] mL/min and 108.0 [90.0-144.0] mL/min, respectively (P = 0.199). The group-B had significantly higher ITA free flow (135.0 [102.0-171.0] mL/min) than group-A (63.0 [36.0-96.0] mL/min, P = 0.009). In 13 patients with bilateral ITA harvesting, free flow of the RITA (138.0 [79.5-204.0] mL/min) was also significantly higher than the LITA (102.0 [81.0-138.0] mL/min, P = 0.046). There was no significant difference between RITA and LITA flow anastomosed to the LAD. The group-B had significantly higher ITA-LAD flow (56.5 [32.3-73.6] mL/min) than group-A (40.9 [20.1-53.7] mL/min, P = 0.023). CONCLUSION: RITA provides significantly higher free flow than LITA but similar blood flow to the LAD. Full skeletonization with intraluminal papaverine injection maximizes both free flow and ITA-LAD flow.

Comparison of two spike areas in bileaflet mechanical valve closing sound.

We previously reported our development of a wavelet analysis system which demonstrates that in vivo bileaflet mechanical valve sound splits into two spikes at higher frequency levels and, based on this system, proposed criteria for detecting malfunctioning bileaflet valves (MBVs). However, the results of that study were only tentative due to the small number of patients with MBVs enrolled in the study. Here, we discuss the possibility of new criteria based on the scalographic properties of two spikes of bileaflet valve sound. The study cohort comprised 12 patients who each received a Carbomedics valve. Based on cinefluoroscopy findings, seven valves were classified into a "normal" group, and the other five were classified into a "malfunction" group. Five consecutive valve sounds for each valve were collected for the wavelet analysis in order to re-evaluate the previously proposed criteria and to measure both anterior spike area (Aa) and posterior spike area (Pa) for calculating the spike area ratio (Aa/Pa). The proposed criteria, namely, a single spike or coefficient of variation of <0.1120 detected only two of the five malfunctioning valves, as well as one normal valve to be malfunctioning. The mean Aa/Pa of all malfunctioning valves [2.45 ± 0.63; 95 % confidence interval (CI) ±1.01, 95 % confidence limits (CL) 1.44-3.46] was significantly higher than that of all normal valves (1.17 ± 0.27; 95 % CI ±0.25, 95 % CL 0.92-1.42). Based on this result, we determined the cutoff value of Aa/Pa to be 1.4. The combination of a single spike on the scalogram and an Aa/Pa of >1.4 detected more MBVs than previously proposed criteria. This combination may represent new criteria for detecting MBVs.

New automated wavelet analytical system with a cellular phone for recording intercellular phone remote transmitted bileaflet valve sound.

The wavelet analytical system developed in our institute can detect a malfunctioning bileaflet valve by analyzing the split interval (SI) of bileaflet valve sound (BLVS) caused by asynchronous closure of both leaflets. However, this system is limited in its clinical application because of the complications of both valve sound recording and analytical protocols. This study established a new system that improved upon these limitations, and evaluated its clinical efficiency and the possibility of intercellular phone remote transmission of BLVS (ICTB). Fifty-one valves in 36 patients with St. Jude Medical bileaflet valve replacement were examined by fluoroscopy, 90 BLVS files (42 mitral and 48 aortic valve files) were recorded, and 1720 individual BLVS recordings in these files were analyzed with the new system. The new system consists of a cellular phone for BLVS recording and an automated algorithm for analysis with the Morlet continuous wavelet transform. ICTB was also investigated clinically. The new system showed great improvement over the original system by simplifying BLVS recording and reducing analysis time by approximately 65%. This system detected two malfunctioning valves with coefficients of variation (CV) for SI below 0.112, a previously proposed criterion for malfunction. ICTB also proved to be a useful BLVS recording method for determining SI. The new system described in this study could eliminate the factors limiting clinical application of the old system, and ICTB was found to be a clinically applicable BLVS recording method.

[Risk factors for the surgical repair of ventricular septal perforation; an 8-year multiinstitutional analysis].

OBJECTIVE: The purpose of this study was to determine the surgical outcomes and risk factors for surgical repair of the ventricular septal perforation (VSP). METHOD: From 1995 to 2003, 41 patients with VSP underwent surgical repair. There were 18 males and 23 females, with the mean age of 71.7 +/- 9.2. Sixteen patients (39.0%) had the preoperative shock, while 30 patients received intraaortic balloon pumping (IABP) assistance and 1 of those required percutaneous cardiopulmonary support (PCPS). Mean durations from onset of myocardial infarction and VSP to operation were 5.8 +/- 9.4 and 2.4 +/- 8.1 days, respectively. Twenty-six patients underwent infarct exclusion technique, 11 underwent patch closure, and 4 Daggett operation. Mean cardiopulmonary and aortic cross-clamp time were 211 +/- 85 and 105 +/- 43 minutes, respectively. RESULTS: Thirty days mortality was 11 (26.8%). Nine patients (22%) required PCPS after repair, however, 2 weaned off the support and only 1 discharged the hospital. Residual shunt was found in 12 patients (29.3%), and 4 underwent the reclosure of the residual shunt 13 +/- 8.6 days after the initial operation, whereas none of patients with PCPS had residual shunt. Univariate analysis revealed the preoperative shock (p = 0.03), longer cardiopulmonary bypass time (p < 0.01), and the need for PCPS after repair (p < 0.01) were the risk factors for the early mortality. Multivariate analysis indicated the cardiopulmonary time over 210 minutes and the need for PCPS to be the significant risk factors. CONCLUSION: The long cardiopulmonary bypass support after repair and the subsequent need for PCPS imply the poor left ventricular function. Since the residual shunt was not the cause of PCPS, the surgical outcome for VSP may be limited in patients with poor left ventricular function. In these patients, other therapeutic strategies may be required, such as ventricular assisting devices, transplantation, or regenerative therapy.

Surgical results for active endocarditis with prosthetic valve replacement: impact of culture-negative endocarditis on early and late outcomes.

OBJECTIVE: Surgical treatment of active infective endocarditis requires not only hemodynamic repair, but also special emphasis on the eradication of the infectious focus to prevent recurrence. This goal can be achieved by the combination of aggressive debridement of infective tissue and appropriate and adequate antibiotic treatment. We reviewed our experience with active endocarditis and identified factors determining early and late outcomes, particularly focusing on the factor of culture-negative endocarditis. METHODS: Sixty seven patients with clinical evidence of active endocarditis who underwent operation between 1991 and 2001 were evaluated. The aortic valve was infected in 28 (42%), the mitral valve in 23 (34%), and multiple valves in 16 (24%). Native valve endocarditis was present in 58 (87%) and prosthetic valve endocarditis in 9 (13%). Mean follow-up was 5.7 years (range, 0.2-11.5 years). RESULTS: Microorganisms were detected in 46 (69%): Staphylococcus aureus in 9 (13%), other staphylococci in 9 (13%), streptococcus species in 19 (28%), and others in 9 (28%), whereas 21 (31%) patients had culture-negative endocarditis. Operative mortality was 17.8% (12 patients). Reoperation was required in 8 (12%), while 3 late deaths (5.5% of hospital survivors) occurred. All events, including death, reoperation, periprosthetic leak, and recurrence of infection, occurred within 2 years after operation. Actuarial freedom from reoperation, late survival, and events at 5 years were 81.6, 76.4, and 68.6%, respectively. On multivariate analysis, no independent adverse predictor was detected for hospital death, whereas the following independent adverse predictors were identified: preoperative heart failure (P=0.0375), prosthetic valve endocarditis (P=0.0391) and culture-negative endocarditis (P=0.0354) for poor late survival; culture-negative endocarditis (P=0.0354) and annular abscess (P=0066) for poor event-free survival. Freedom from events was similar between patients with Staphylococcus aureus infection (3-year freedom 55.6%) and culture-negative endocarditis (3-year freedom 47.6%), whereas events were significantly low in patients with streptococcus infection (3-year freedom 100%). CONCLUSIONS: In our analysis, no independent adverse predictor was detected for hospital death; however, culture-negative endocarditis was identified as an independent predictor for both late survival and events after surgery. Event-free survivals were similar between staphylococcus infection and culture-negative endocarditis, and all events occurred within 2 years after operation, suggesting the necessity of close follow-up during that period.

Bilateral coronary ostial patch angioplasty with autologous pericardium in Takayasu arteritis: a case requiring replacement of the aortic valve and ascending aorta.

Since the lesions and stages of Takayasu arteritis vary with each patient, surgical treatment of this disease requires meticulous planning for the timing of operation, technique, material used, and postoperative medication. We report a rare complex lesion of Takayasu arteritis, which required simultaneous repairs for aortic regurgitation, a dilated ascending aorta and bilateral coronary ostial stenosis. Such multiple lesions have not been reported previously. A 47-year-old woman was referred to us because of heart failure and chest pain. The coronary ostial stenosis were enlarged with generously sized autologous pericardial patches, and separate aortic valve and ascending aortic replacements were performed since the diameter of the Valsalva sinus was 37 mm. The postoperative course was uneventful, but steroid therapy was commenced postoperatively because inflammatory reaction remained high.

[Aortic root redissection associated with the use of gelatin-resorcin-formalin glue following surgical treatment for acute type A aortic dissection; report of a case].

A late redissection case of the aortic root after total arch replacement for acute Stanford type A aortic dissection was reported. A 55-year-old male was treated with total arch replacement for acute Stanford type A aortic dissection. The aortic valve was bicuspid valve, and the right coronary leaflet was prolapsed because of the dissection of right and non coronary cusp. Resuspension of the commissure and the fixation of the dissected aortic wall with gelatin-resorcin-formalin (GRF) glue was performed during the operation. The initial postoperative course was uneventful and the patient discharged 52 days after the operation. Redissection of aortic root was pointed out on the computed tomography (CT) 3.5 years after the operation. As the second operation, the aortic root replacement was performed. Coronary artery bypass for right coronary artery was simultaneously performed with right internal thoracic artery because the right coronary ostium was stenotic and showed ischemic change on electrocardiogram monitor during the operation. The redissection was seen on the right coronary sinus, which was fixed by the GRF glue during the first operation. The pathological study showed the migration of macrophages and the tear of the fibrous tissue. These findings was thought to be associated with the use of the GRF glue. Careful use of the GRF glue for the fixation of the dissected aorta during the surgical treatment for the Stanford type A aortic dissection was thought to be important.

Can we change the operative criteria for the MAZE procedure combined with valve surgery in the era of radiofrequency devices?

PURPOSE: After radiofrequency (RF) ablation became available, the indication of MAZE procedure conducted with bipolar RF was expanded. We examined the efficacy and feasibility of the RF MAZE procedure in valve surgery and identified the predictors of atrial fibrillation (AF) recurrence. METHODS: Forty-four patients had permanent AF at the time of operation and underwent a biatrial RF MAZE procedure. Univariate and multivariate analysis for the predictor of permanent AF recurrence and follow-up studies were performed. RESULTS: Of the patients, 37 (84.1%) were in non-AF rhythm at discharge and 25 (80.6%) were at the latest follow-up (mean, 2.1 ± 1.2 years). In stepwise multivariate analysis, left atrial dimension (LAD) > 61.5 mm was an independent predictor of early-term recurrence of AF (P = 0.006) and late-term recurrence (P = 0.038) as well. F-wave voltage <0.1 mV was significant in univariate analysis but was not significant in multivariate analysis for predictor of late-term AF recurrence. Avoidance of AF in the late term was 56% for LAD > 60 mm whereas it was 91% for LAD ≤ 60 mm (P = 0.043), 67% for F-wave < 0.1 mV compared to 100% for F-wave ≥ 0.1 mV (P = 0.031), and 43% for LAD > 60 mm and F-wave < 0.1 mV compared to 91% for LAD ≤ 60 mm and/or F-wave ≥ 0.1 mV (P = 0.016), respectively. Although avoidance of AF in the late term was lower in patients with LAD > 60 mm or F-wave < 0.1 mV, more than half of these patients were free from AF in the late term. CONCLUSION: LA size was assumed to be a simple and strong predictor of recurrent AF in this procedure. Predictive criteria that had been widely employed for the "cut-and-sew" MAZE procedure accompanied with valve surgery can be expanded in the MAZE procedure with RF devices.

Measured tube technique for ensuring the correct length of slippery artificial chordae in mitral valvuloplasty.

Mitral valvuloplasty using Gore-Tex (W.L. Gore & Associates, Inc, Flagstaff, AZ) as artificial chordae is often associated with difficulties in determining the length of the artificial chordae, as well as preventing knot slippage, especially for patients with broad anterior leaflet prolapse. We describe a simple technique that enables surgeons to easily determine the correct length of the artificial chordae and tie slippery knots without using a specific device.

Temporary right ventricular support with Impella Recover RD axial flow pump.

Post-cardiotomy right ventricular failure is a serious complication that frequently results in adverse outcomes. We reviewed our experience with the Impella Recover RD (Impella Cardiosystems GMbH, Aachen, Germany). From January 2007 to December 2007, 7 patients (5 males, 54 +7 years old) had this device implanted for temporary support after heart transplantation in 4, after repeat mitral valve replacement in 2, and with a left ventricular assist device in 1. Devices were implanted during initial operation (n =5) or shortly thereafter (n =2). Six patients underwent implantation without cardiopulmonary bypass. Effective support with pump flows of 4.0-4.5 L x min(-1) and adequate unloading (central venous pressure decreased from 15.3 +/- 1.4 to 9.4 +/- 1.2 mm Hg) was achieved in all patients. Patients were assisted for a mean duration of 4.9 +/- 4.5 days. Three patients could be weaned after 7.0 +/- 5.6 days of support and underwent device explantation without cardiopulmonary bypass. One of these patients died of recurrent right ventricular failure, 2 remained stable but died later of sepsis. The patient with a left ventricular assist device was switched to an alternative device for prolonged support. Two patients experienced pump dysfunction. Our preliminary experience shows that the Impella Recover RD is an effective device that can be easily implanted and explanted. However, its mechanical reliability needs to be improved.

Wavelet analysis of valve closing sound detects malfunction of bileaflet mechanical valve.

Several studies have reported the asynchronous closure of normal bileaflet valves (NBVs), resulting in a split in its closing sound; however, the clinical significance of this split has never been studied in malfunctioning bileaflet valves (MBVs). The study comprised 218 valves in 184 patients, including normal monoleaflet valves (n = 10), NBVs (n = 198), and MBVs (n = 10). Valve function was confirmed by cinefluoroscopy prior to analysis of the valve sound by the Morlet continuous wavelet transform (CWT). The split interval (SI) for each heartbeat was measured, and the coefficient of variation (CV) of its mean (valve SI) was calculated as a parameter for the fluctuation of the SI. The CWT of monoleaflet valves showed a single spike, whereas NBVs exhibited a clear split. There was no significant difference in valve SI between the aortic and mitral positions; however, the mean of the CV was significantly greater in the mitral position (n = 90, 0.507 +/- 0.254) than in aortic position (n = 108, 0.353 +/- 0.228, P = 0.000045). The split was not found in six (aortic; three, mitral; three) of ten patients with MBVs. The other four patients had a distinct split, but the CV was significantly lower for MBVs (0.138 +/- 0.105) than for NBVs (0.343 +/- 0.221, P = 0.042). Receiver-operating characteristics analysis demonstrated the cutoff line of the CV to be 0.112 for detecting malfunctioning aortic valves with the highest accuracy of 86.1%. This new system using the Morlet CWT can detect MBVs. It will be a useful modality for screening the function of bileaflet valves.

Off-pump aortic arch repair through a median sternotomy for type B interrupted aortic arch with single ventricle physiology.

BACKGROUND: The aortic arch repair for interrupted aortic arch (IAA) with the hypoplastic ascending aorta through a median sternotomy requires cardiopulmonary bypass (CPB), which is very invasive in neonates and complicates pulmonary artery banding (PAB) is staged repair. METHODS: A 22-day-old neonate with a type B IAA having a functional single ventricle underwent arch repair and PAB through a median sternotomy without CPB. A partial occlusion clamp could be placed on the ascending aorta without cerebral malperfusion and the descending aorta could be directly anastomosed to the ascending aorta in an end-to-side fashion under stable circulatory condition. Thereafter, the tight PAB was performed with a circumference of 23mm without any difficulty. RESULTS: The postoperative echocardiogram revealed no stenosis on the anastomotic site and the patient was discharged uneventfully. CONCLUSION: This approach is effective in neonates with IAA who require staged repair, and least invasive for them.

Wavelet analysis of bileaflet mechanical valve sounds.

It has been reported that asynchronous leaflet closure in a bileaflet mechanical valve causes a split in the valve closing sound. We have previously reported that the continuous wavelet transform (CWT) with the Morlet wavelet as modified by Ishikawa (the Morlet wavelet) is the most suitable method among the CWTs for detecting a split in the bileaflet mechanical valve sound because this method can detect the highest frequency signal among the CWT methods with higher time resolution. This is the first article which discusses the acoustic properties of five types of bileaflet valves using the Morlet CWT. Similar behavior of the valve sound split intervals with wide fluctuations over consecutive heartbeats was found to be the common finding for all the bileaflet valves. This result suggests that fluctuation of the split interval proves the normal movement of both leaflets without movement disturbance. The mean differences in the split interval between these bileaflet valves were statistically significant, and the wavelet coefficients of the CWT showed characteristic scalographic patterns, such as a teardrop shape or a triangle beneath the split. However, these two findings gave no valuable information for the diagnosis of bileaflet valve malfunction. A split in the valve closing sound with a fluctuating interval was the common finding in these five normally functioning bileaflet valves, and careful observation of the split's behavior may be a key to diagnosis of bileaflet valve malfunction.