Isolated pulmonary valve replacement: analysis of 27 years of experience

The aim of this study was to investigate the longterm results of isolated pulmonary valve replacement using xenobioprostheses or mechanical valves. Twenty-four cases of isolated pulmonary valve replacement carried out at Kyushu University Hospital between 1977 and 2004 were reviewed. Those undergoing Rastelli's operation were excluded from this study. Bioprostheses were used in 18 patients and mechanical valves in 6. There were no operative deaths. Two patients with mechanical valves needed repeat pulmonary valve replacement due to thrombosed valves. The patients with bioprostheses had no need of repeat replacement postoperatively. The cardiothoracic ratio significantly improved from 60.3% preoperatively to 55.4% postoperatively (P < 0.05), and the New York Heart Association (NYHA) class significantly improved from 2.0 preoperatively to 1.1 postoperatively (P < 0.05). The actuarial survival rate at 15 years was 92.3%. The valve-related event-free ratio at 15 years was 85.7% in the bioprosthesis group and 66.7% in the mechanical valve group, with no significant difference. Isolated pulmonary valve replacement with bioprostheses or mechanical valves can be safely done and showed satisfactory long-term results. The mechanical valve group demonstrated a high ratio of thrombosed valves. A bioprosthesis is recommended for pulmonary valve replacement if a homograft is not available.     

Echocardiographic characteristics of transprosthetic blood peak velocity in the Sorin Bicarbon bileaflet prosthetic heart valve

The Bicarbon prosthetic heart valve with two curved leaflets is designed so that the blood flows through the three orifices are parallel jets of equal size. This study was conducted to confirm that the Bicarbon valve functions clinically as designed. Forty-three patients underwent valve replacement with the Bicarbon valve. Forty-eight Bicarbon valves were implanted: 25 valves in the mitral position and 23 in the aortic position. Peak blood flow velocity through the three prosthetic orifices was measured postoperatively by Doppler echocardiography. The three flow jets through the prosthesis were parallel. The velocity through the lateral orifice was 2.33±0.38 m/min, and the velocity through the central orifice was 2.14±0.43 m/min at the aortic position (P>0.05). The velocity through the lateral orifice was 1.72±0.06 m/min at the mitral position, and that through the central orifice was 1.73±0.06 m/min (P>0.05). Serum lactic acid dehydrogenase values were also lower than those of patients or whom another bileaflet prosthesis had been implanted. The results confirm that the Bicarbon prosthetic heart valve performs clinically as designed, producing three parallel blood flow jets with equal flow velocity.     

Mechanism for cavitation of monoleaflet and bileaflet valves in an artificial heart

It is possible that mechanical heart valves mounted in an artificial heart close much faster than those used for clinical valve replacement, resulting in the formation of cavitation bubbles. In this study, the mechanism for mechanical heart cavitation was investigated using the Medtronic Hall monoleaflet valve and the Sorin Bicarbon bileaflet valve mounted at the mitral position in an electrohydraulic total artificial heart. The valve-closing velocity was measured with a charge-coupled device (CCD) laser displacement sensor, and images of mechanical heart valve cavitation were recorded using a high-speed video camera. The valve-closing velocity of the Sorin Bicarbon bileaflet valve was lower than that of the Medtronic Hall monoleaflet valve. Most of the cavitation bubbles generated by the monoleaflet valve were observed near the valve stop; with the Sorin Bicarbon bileaflet valve, cavitation bubbles were concentrated along the leaflet tip. The cavitation density increased as the valve-closing velocity and the valve stop area increased. These results strongly indicate that squeeze flow holds the key to cavitation in the mechanical heart valve. From the perspective of squeeze flow, bileaflet valves with a low valve-closing velocity and a small valve stop area may cause less blood cell damage than monoleaflet valves.     

Thrombogenic influence of biomaterials in patients with the Omni series heart valve: pyrolytic carbon versus titanium

An opportunity to assess the thromboembolic rates caused by the construction materials on valve replacements is possible with the Omni series of mechanical heart valves. The Omnicarbon and Omniscience valves are identical in form but differ in that the Omnicarbon valve is constructed entirely of pyrolytic carbon, whereas the Omniscience valve uses titanium for its housing, the rest of its structure being pyrolytic carbon. The literature was reviewed and a comparison in similar groups of patients was made between these two model valves for their thromboembolic rates in the mitral and aortic positions. A total of 569 aortic Omnicarbon valves (4,146 patient years [pt yrs.1) had a thromboembolic events (T/E rate) of 0.5% compared with 1.7% for 468 aortic Omniscience (1,552 pt yrs); p < 0.0001. A total of 298 mitral Omnicarbon valves (3,333 pt yrs) had a T/E rate of 1.6% compared with 2.6% for 716 mitral Omniscience valves (2,134 pt yrs), p < 0.001. There was no difference in the anticoagulation management between the two model valves although the Omniscience valve required higher prothrombin or International Normalized Rate maintenance levels, which resulted in higher bleeding rates among patients with Omniscience valves.     

Hydrodynamics of a Newly China-Made Jiuling Bileaflet Heart Valve Prostheses

INTRODUCTION　　 Implantation of heart valve substitute has become the standard treatment forend-stage valvular heart disease since the1 960 s.There are two different types ofmechanical heart valve in widespread use at present,the tilting disc valve and t…     

Effects of leaflet geometry on the flow field in three bileaflet valves when installed in a pneumatic ventricular assist device

Our group is currently developing a pneumatic ventricular assist device (PVAD). In this study, in order to select the optimal bileaflet valve for our PVAD, three kinds of bileaflet valve were installed and the flow was visualized downstream of the outlet valve using the particle image velocimetry (PIV) method. To carry out flow visualization inside the blood pump and near the valve, we designed a model pump that had the same configuration as our PVAD. The three bileaflet valves tested were a 21-mm ATS valve, a 21-mm St. Jude valve, and a 21-mm Sorin Bicarbon valve. The mechanical heart valves were mounted at the aortic position of the model pump and the flow was visualized by using the PIV method. The maximum flow velocity was measured at three distances (0, 10, and 30 mm) from the valve plane. The maximum flow velocity of the Sorin Bicarbon valve was less than that of the other two valves; however, it decreased slightly with increasing distance it the X-Y plane in all three valves. Although different bileaflet valves are very similar in design, the geometry of the leaflet is an important factor when selecting a mechanical heart valve for use in an artificial heart.     

Evaluation of coagulant activity after mechanical heart valve replacement

Long-term oral anticoagulant therapy is required for recipients of mechanical heart valves. In our hospital, the international normalized ratio of prothrombin time (PT-INR) has been set in the range 1.5–2.5 since October 2001. To evaluate whether coagulant activity is fully suppressed by this target range, coagulant activity was evaluated by measuring thrombin–antithrombin III complex (TAT) levels and valve-related complications were investigated retrospectively. Two hundred twenty-three patients who underwent mechanical valve replacement were enrolled in this study. PT-INR and TAT were measured at our outpatient clinic in March 2005 and valve-related complications since October 2001, when we started to control PT-INR in the range 1.5–2.5, were investigated. Under adequate warfarin control, there was no significant correlation between PT-INR and TAT, however nine patients who exhibited a PT-INR of less than 2.0 had high levels of TAT. And in atrial fibrillation (AF) patients after mitral valve replacement (MVR), the level of TAT was significantly high compared with sinus rhythm patients after atrial valve replacement. Valve-related complications were bleeding events at 2.75% per patient year and thromboembolism at 0.32% per patient year. Attention to complications of thromboembolism is necessary when the PT-INR is less than 2.0, especially in AF patients after MVR and in those with a thrombotic past history or high levels of TAT. The monitoring of TAT is useful in detecting potential coagulation factors and to determine the therapeutic range of warfarin that can normalize coagulant activity.     

Laser Doppler Anemometry Study of Bidimensional Flows Downstream of Three 19 mm Bileaflet Valves in the Mitral Position, Under Kinematic Similarity

Three small-size (nominal size: 19 mm) bileaflet valves, CarboMedics R (CM), St Jude Standard (SJ) and Sorin Bicarbon (SB), have been tested by means of a two-component laser Doppler anemometry (LDA) system, in the mitral position, in order to assess the potential damage to blood elements entailed by the turbulent flow through them. A high regime (6 l/min cardiac output) was chosen to perform measurements for the worst case in generated turbulence. Two half-diameter profiles, at 13 and 26 mm downstream of the valve plane, have been investigated for each model. Besides velocity profiles, turbulence shear stresses (TSS) are reported, after the application of the stress analysis technique, in order to assess the maximum values of TSS (TSS_max exerted on blood particles. Results show the typical bileaflet-type velocity profile for SB and SJ, with three jets exiting the valve, whereas CM lacks the central jet, due to instabilities of its flow field. As for TSS_max, CM reaches the highest values, presumably due to leaflets fluttering. SJ's TSS_max profiles maintain similar shapes at the two downstream locations, whereas SB presents an unexpected increase in the peak value of TSS_max from 13 to 26 mm downstream of the valve plane, probably due to the curved leaflet design. The three prosthetic heart valves (PHVs) tested show many differences as for their turbulence properties, although they are similarly constructed.     

Method of ranking of heart valve characteristics at mitral position based on statistical model analysis

The purpose of this study was to explore a valve selection criterion based on the impact force generated at valve closure, and to test a statistical mathematical model for comparing valve performance. The impact force generated at valve closure in the mitral position was measured continuously, using a load cell mounted in the left atrial section of a mock circulatory system. Eight clinical valves were tested. The data obtained from the in vitro test were subjected to multiregression analysis, to enable systematic comparison of the impact forces of these valves. Further-more, class I quantification, theory was applied to construct the statistical mathematical model. As a result, the following interaction effect was observed in the statistical model. (1) The impact force generated at valve closure had a lower value in valves of smaller diameter. (2) The ranking of 29-mm-diameter valves by impact force was different for the flow region. Under the physiological flow condition of 4–61/min, high impact forces were generated in all valves, in the order Björk-Shiley monostrut, ATS, St. Jude medical, CarboMedics. We consider that low impact force at valve closure is desirable, upon consideration of the influence on the annulus tissue at valve replacement. From these findings, the results of the multiregression analysis provide indications for choosing the optimal value for patients with severe mitral insufficiency (MI).     

Mid-term results of 17-mm St. Jude Medical Regent prosthetic valves in elder patients with small aortic annuli: comparison with 19-mm bioprosthetic valves

This study was designed to compare the mid-term outcomes after aortic valve replacement (AVR) between 17-mm mechanical heart valves (MV) and 19-mm bioprosthetic valves (BV) in elderly patients with small aortic annuli. Between 2000 and 2011, 127 consecutive patients (mean age 79 years; 87 % female) underwent AVR for aortic valve stenosis with a small aortic annulus. 19-mm BV (n = 67) was implanted. When the 19-mm BV did not fit the annulus, 17-mm St. Jude Medical Regent prosthetic mechanical valve (n = 60) was used instead of an aortic root-enlargement procedure. The follow-up rate was 94.0 % in the BV group, and 98.5 % in the MV group. No significant differences in survival rate and valve-related complications were found between the 2 groups. In-hospital mortality rates were 1.5 % (n = 1) in the BV group and 5.0 % (n = 3) in the MV group. Late mortality rates were 3.9 % per patient-years (p-y; n = 8) in the BV group, and 6.0 % per p-y (n = 10) in the MV group. Five-year Kaplan–Meier survival rates were 62 % in the BV group, and 72 % in the MV group (log-rank P = 0.280). Freedom from major adverse valve-related stroke and cerebral bleeding events was 92.5 and 98.5 % in the BV group, and 94.7 and 100 % in the MV group. AVR using 17-mm MV in elder patients with small aortic annuli provided equivalent mid-term clinical results to that with 19-mm BV.     

Patient–prosthesis mismatch may be irrelevant after aortic valve replacement with the 19-mm Perimount pericardial bioprosthesis in patients aged 65 years or older

The prevalence of patient–prosthesis mismatch (PPM) and its influence on clinical midterm results were examined in elderly patients whose activity was supposed to be less than that of younger patients. We evaluated valve function and the effects of PPM on the midterm results of the 19-mm Carpentier–Edwards Perimount (CEP) pericardial aortic valve in patients aged 65 years or older. Between August 1996 and May 2005, 51 patients underwent aortic valve replacement with the 19-mm CEP valve. The mean follow-up was 2.4 ± 1.8 years, involving a total of 134.4 patient-years. The mean age and body surface area at operation were 74.0 ± 5.0 years and 1.41 ± 0.14 m². There were two (3.9%) operative deaths. Three patients (5.9%) underwent enlargement of their small aortic annuli. The actuarial survival rate at 8 years, including operative mortality, averaged 90.2% ± 4.7%. The freedom from thromboembolism, reoperation, and valve-related mortality averaged 75.0% ± 21.7%, 97.8% ± 2.2%, and 95.3% ± 3.2%, respectively, at 8 years. High preoperative peak and mean transvalvular pressure gradients were significantly improved after the operation (peak, 93 ± 35 versus 28 ± 12 mmHg; mean, 58 ± 19 versus 17 ± 7 mmHg, respectively; P < 0.01). The mean left ventricular mass index was reduced from 192 ± 44 to 142 ± 46 g/m² at late follow-up (P < 0.01). The prevalence of PPM was low (17.6%) when an indexed effective orifice area of less than 0.85 cm²/m² was taken as the definition of PPM. The clinical results, postoperative pressure gradients, and reduction in left ventricular mass index were not different between the PPM and no-PPM groups. The 19-mm CEP valve produced satisfactory midterm clinical outcomes in patients aged 65 years or older whose activity was supposed to be less than that of younger patients, regardless of the presence or absence of PPM. Moderate PPM was rare and it did not adversely impact on the midterm results. The application of annulus enlargement could be limited to the small number of patients for whom the 19-mm CEP valves are not able to be inserted.     

Increased risk for double valve replacement with tissue and mechanical prostheses

We wanted to determine whether there is any advantage of using a mitral tissue valve, when aortic and mitral valves are simultaneously replaced. We placed a tissue valve in the mitral position and a mechanical valve in the aortic position in 22 cases (combined group). In 31 other double valve replacements, mechanical prostheses were chosen for both positions (mechanical group). The mean follow-up time for the combined group was 8.9 years, and that for the mechanical group was 7.2 years. The 10-year survival rate and freedom from thromboembolism at 10 years were not different in the two groups. Treatment-related hemorrhage was seen in 3 patients of the combined group alone. Five patients among the combined group underwent reoperation because of bioprosthetic dysfunction, and the rate of freedom from reoperation at 10 years was 75 ±12%. The rate of freedom from all complications at 10 years was 43±11% for the combined group and 70±8% for the mechanical group. We find no advantage in mixing aortic mechanical and mitral tissue valves when performing double valve replacement.     

Observation of cavitation in a mechanical heart valve in a total artificial heart

Recently, cavitation on the surface of mechanical heart valves has been studied as a cause of fractures occurring in implanted mechanical heart valves. The cause of cavitation in mechanical heart valves was investigated using the 25 mm Medtronic Hall valve and the 23 mm Omnicarbon valve. Closing of these valves in the mitral position was simulated in an electrohydraulic totally artificial heart. Tests were conducted under physiologic pressures at heart rates from 60 to 100 beats per minute with cardiac outputs from 4.8 to 7.7 L/min. The disk closing motion was measured by a laser displacement sensor. A high-speed video camera was used to observe the cavitation bubbles in the mechanical heart valves. The maximum closing velocity of the Omnicarbon valve was faster than that of the Medtronic Hall valve. In both valves, the closing velocity of the leaflet, used as the cavitation threshold, was approximately 1.3-1.5 m/s. In the case of the Medtronic Hall valve, cavitation bubbles were generated by the squeeze flow and by the effects of the venturi and the water hammer. With the Omnicarbon valve, the cavitation bubbles were generated by the squeeze flow and the water hammer. The mechanism leading to the development of cavitation bubbles depended on the valve closing velocity and the valve stop geometry. Most of the cavitation bubbles were observed around the valve stop and were generated by the squeeze flow.     

Long-term results of mitral valve replacement: biological xenograft versus mechanical valves

 We studied 279 patients who underwent mitral valve replacement at the Department of Thoracic and Cardiovascular Surgery, Hyogo College of Medicine, between November 1973 and December 1998. The patients were divided into two groups based on the type of replacement valve (154 patients in the biological xenograft group and 125 patients in the mechanical valve group), and the long-term results were compared. Clinically satisfactory results were obtained in both the biological xenograft group and the mechanical valve group according to the surgical results, long-term survival, and incidence of prosthetic valve endocarditis. At 15 years, fewer patients in the mechanical valve group than in the biological xenograft group were free of bleeding events (92.5 ± 3.7% vs 100% P < 0.05). At 15 years, the biological xenograft group was lower than the mechanical valve group with respect to freedom from thromboembolism (72.2 ± 4.6% vs 93.5 ± 3.6% P < 0.01), freedom from valve failure (22.0 ± 5.2% vs 87.0 ± 4.1% P < 0.005) and freedom from cardiac events (16.5 ± 3.9% vs 47.2 ± 14.5% P < 0.01). Though it has previously been suggested that biological xenografts used in mitral valve replacement do not need anticoagulation, the current study suggests the need for anticoagulation with the use of biological xenografts. Mechanical valves require close monitoring of anticoagulation, but their use has decreased the incidence of valve failure and thromboembolism, as compared with the use of biological xenografts. Therefore, mechanical valves are currently the preferred choice for mitral valve replacement. We believe that biological xenografts are indicated only for the older patient (≧65 years). Received: August 1, 2002 / Accepted: October 28, 2002 Correspondence to:H. Yao     

Incidence and outcomes of infective endocarditis after transcatheter aortic valve implantation versus surgical aortic valve replacement

ObjectivesTranscatheter aortic valve implantation (TAVI) is an alternative to surgical aortic valve replacement (AVR) in aortic stenosis (AS). Infective endocarditis (IE) in patients with prosthetic heart valves is associated with significant morbidity and mortality. Data on the incidence, risk factors, and outcomes of IE after TAVI are conflicting. We evaluated these issues in patients with percutaneous TAVI vs. isolated surgical AVR (SAVR) at a nationwide level.MethodsBased on the administrative hospital discharge database, the study collected information for all patients with aortic stenosis treated with AVR in France between 2010 and 2018.ResultsA total of 47 553 patients undergoing TAVI and 60 253 patients undergoing isolated SAVR were identified. During a mean follow-up of 2.0 years (median (25th to 75th percentile) 1.2 (0.1–3.4) years), the incidence rates of IE were 1.89 (95% confidence interval (CI) 1.78–2.00) and 1.40 (95% CI 1.34–1.46) events per 100 person-years in unmatched TAVI and SAVR patients, respectively. In 32 582 propensity-matched patients (16 291 with TAVI and 16 291 with SAVR), risk of IE was not different in patients treated with TAVI vs. SAVR (incidence rates of IE 1.86 (95% CI 1.70–2.04) %/year vs 1.71 (95% CI 1.58–1.85) %/year respectively, relative risk (RR) 1.09, 95% CI 0.96–1.23). In these matched patients, total mortality was higher in TAVI patients with IE (43.0% 95% CI 37.3–49.3) than in SAVR patients with IE (32.8% 95% CI 28.6–37.3; RR 1.32, 95% CI 1.08–1.60).DiscussionIn a nationwide cohort of patients with AS, treatment with TAVI was associated with a risk of IE similar to that following SAVR. Mortality was higher for patients with IE following TAVI than for those with IE following SAVR.     

Long-term experience with the Bjork-Shiley Monostrut tilting disc valve

The Bjork-Shiley Monostrut valve is tilting disc mechanical valve prosthesis. This study was designed to present the long-term outcome of our experience. One hundred and thirty-seven Bjork-Shiley Monostrut valves were implanted in 101 consecutive patients from November 1983 to February 1990. There were 60 male and 41 female with mean age of 34.5 yr at the time of operation. Fifty-nine patients underwent single valve replacement, 38 had double valve, and 4 had triple valve replacement. There were six in-hospital deaths (5.9%): three from cardiopulmonary bypass weaning failure and one each from septic shock, sudden cardiac arrest, and uncontrollable bleeding. Mean duration of follow-up was 181.2+/-76.2 months. Overall survival was 86.2% at 15 yr and 83.1% at 20 yr. Patients with mitral valve replacement had 93.5% and 90.2% cumulative survival at 10 and 15 yr, respectively, while patients with aortic valve replacement had 91.1% and 86.5% cumulative survival at 10 and 15 yr. Two groups had no significant difference in survival. Double valve replacement patients had 92.2% and 84.0% survival at 10 and 15 yr, respectively. There were no significant differences in survival between the single and double valve replacement groups. Freedom from thromboembolism was noted in: 97.8%, 97.8%, 96.4% and 87.8% at 5, 10, 15 and 20 yr, respectively. Absence of endocarditis was noted in 98.6% and 94.8% at 15 and 20 yr. Absence of reoperation was 92.5% at 20 yr. In conclusion, the Bjork-Shiley Monostrut valve is reliable, with a similar incidence of valve-related morbidity as in other mechanical valves.     

An analysis of autopsy findings in 108 patients who died after valve replacement

The pathological findings and the causes of death were reviewed in 108 patients who had received 142 heart valve prostheses (52 mechanical and 90 bioprostheses) at the National Cardiovascular Center in Osaka, Japan, from 1977 to 1991. Rheumatic heart disease was the major underlying disease (60.2%), and the age distribution at death ranged from 21 to 80-year-old. Survival duration after the surgery extended from 0 day to 9 years. Thirty-three patients (30.6%) died of perioperative complications such as myocardial haemorrhage and damage, or from heart failure which had been evident prior to the operation, a cause of death which predominated in patients who died within 1 week of surgery (15/17; 88.2%). Thirty-eight patients (35.2%) died of prostheses-related problems such as prosthetic valve failure (cuspal tears and calcifying destruction of the xenograft), thromboembolism, and prosthetic valve endocarditis. Endocarditis was frequent in patients who had survived longer than 1 year (25/33; 75.8%). None of the patients died of prostheses-related problems within 1 week. Non-infectious valve failure was more common in patients with bioprostheses than in those with mechanical valves; thromboembolism showed the opposite association. Prosthetic valve infective endocarditis was nearly equal in frequency in both types of valve.     

Midterm results of aortic valve replacement with Carpentier-Edwards porcine bioprosthesis

 Since 1987 we have been using Carpentier-Edwards porcine bioprostheses for aortic valve replacements in patients of advanced age and those with a contraindication for anticoagulation therapy. The purpose of this study was to provide insight into the midterm results of our series of patients with Carpentier-Edwards porcine bioprostheses in the aortic position. From September 1987 through June 1999, 31 patients underwent aortic valve replacement with Capentier-Edwards porcine bioprostheses. The age of the patients ranged from 21 to 89 (average, 71 ± 11 years old), and 21 patients (67.7%) were 70 years old or older. There were no operative deaths. Three hospital deaths (9.7%) and one nonhospital death (3.2%) took place. The actuarial survival rate of 31 patients was 90.3% at 5 years and 81.3% at 7 years. Valve-related complications were seen in six patients (19.4%). The postoperative Doppler peak gradient of aortic prostheses was less than 30 mm Hg in all groups, irrespective of valve size. In conclusion, the Carpentier-Edwards porcine bioprosthesis affords good durability with a low rate of valve-related complications and reoperation. Furthermore, the postoperative function of the prosthesis was reasonable in the Doppler echo studies. Received: November 16, 2001 / Accepted: August 12, 2002 Correspondence to:J. Sakata     

Surgical pathology of 104 tricuspid valves (2000–2005) with classic right-sided Ebstein''s malformation

BACKGROUND: Ebstein's anomaly has been described extensively in autopsy material. However, there have been no large surgical pathology series of this malformation. OBJECTIVE: To review clinical and surgical pathologic features of a large number of cases of Ebstein's anomaly from a single institution. METHODS: Review of medical histories, surgical reports, and surgical pathology reports at the Mayo Clinic (2000-2005). RESULTS: Among 104 patients, the mean age was 31 years (2 months-79 years), and 57% were female. Common ECG abnormalities included right bundle branch block (58%), first-degree heart block (31%), preexcitation (18%), and nonspecific intraventricular conduction delay/block (15%). Moreover, 74% had inter-atrial communication, 13% mitral valve prolapse, and 5% bicuspid aortic valve. Clinically, all had tricuspid regurgitation (severe in 74%), and 17% of anterior leaflets were fenestrated. No tricuspid valve was calcified. Surgically, tricuspid tissue was removed during replacement in 99% and repair in 1%. The anterior tricuspid leaflet was resected in 98%, and its length was 0.81-9.3 cm/m2 body surface area (mean, 3.3). Characteristically, leaflets were large and had irregular shapes and numerous short cordal or direct myocardial insertions. One tricuspid valve had two papillary fibroelastomas. None had clinical or pathologic evidence of active or healed endocarditis. CONCLUSIONS: Among patients with Ebstein's malformation, tricuspid valve tissue almost exclusively was removed during valve replacement and represented the anterior leaflet. Valve tissue was generally large, irregularly shaped, and associated with insertion of short cords or myocardial stumps. Interestingly, although appreciably deformed, Ebstein valves were not associated with infective endocarditis.