One frame and several new infinite families of Z-cyclic whist designs

AbstractIn 2001, Ge and Zhu published a frame construction which they utilized to construct a large class of Z-cyclic triplewhist designs. In this study the power and elegance of their methodology is illustrated in a rather dramatic fashion. Primarily due to the discovery of a single new frame it is possible to combine their techniques with the product theorems of Anderson, Finizio and Leonard along with a few new specific designs to obtain several new infinite classes of Z-cyclic whist designs. A sampling of the new results contained herein is as follows: (1) Z-cyclic Wh(33p+1), p a prime of the form 4t+1; (2) Z-cyclic Wh(32n+1s+1), for all n⩾1, s=5,13,17; (3) Z-cyclic Wh(32ns+1), for all n⩾1, s=35,55,91; (4) Z-cyclic Wh(32n+1s), for all n⩾1, and for all s for which there exist a Z-cyclic Wh(3s) and a homogeneous (s,4,1)-DM; and (5) Z-cyclic Wh(32ns) for all n⩾1, s=5,13. Many other results are also obtained. In particular, there exist Z-cyclic Wh(33v+1) where v is any number for which Ge and Zhu obtained Z-cyclic TWh(3v+1)

Quantification of Ventricular Volume Load in the Context of a Bidirectional Cavopulmonary Shunt:A Theoretical Treatise

Background. Functional univentricular hearts are currently palliated by a staged procedure of which the bidirectional cavopulmonary shunt is usually the second stage. In addition to this stage, a calibrated amount of additional pulmonary blood flow may be preserved to promote pulmonary artery growth and increase the length of the interval preceding the total cavopulmonary connection. However, additional pulmonary blood flow can be deleterious for ventricular functioning and development as it increases functional ventricular volume load. Methods. Using the Fick principle we devised a theoretic framework to estimate the ventricular volume loading caused by additional pulmonary and collateral aortopulmonary flow. To use this framework, blood samples need to be taken intraoperatively from the aorta, pulmonary veins, and inferior caval vein to determine oxygen saturations. The oxygen saturation samples have to be taken sequentially with and without additional pulmonary blood flow. Results. The objective of this paper is to provide a theoretic framework to estimate the ventricular volume loading caused by collateral aortopulmonary flow and additional pulmonary blood flow in the context of a bidirectional cavopulmonary shunt in the staged palliation of univentricular hemodynamics. The formulas have not yet systematically been applied in vivo. Conclusions. The added volume loading of the ventricle caused by additional pulmonary blood flow can theoretically be estimated using the newly devised formulas so as to calibrate ventricular volume loading to a desired level intraoperatively. (Ann Thorac Surg 2012;93:2022-7) (C) 2012 by The Society of Thoracic Surgeon

The Effect of Additional Pulmonary Blood Flow on Timing of the Total Cavopulmonary Connection

Background. The staged Fontan procedure is used to palliate functionally univentricular hearts. The effect of additional pulmonary blood flow combined with a bidirectional cavopulmonary shunt in these patients remains a controversial subject. Methods. This retrospective study included all 82 patients with a unilateral or bilateral bidirectional cavopulmonary shunt at our institution between April 1990 and July 2010. Patients with hypoplastic left heart syndrome were excluded. Two groups, based on the presence (n = 57) or absence (n = 25) of additional pulmonary blood flow after the bidirectional cavopulmonary shunt, were compared. Results. Patients with a bidirectional cavopulmonary shunt combined with additional pulmonary blood flow had higher arterial oxygen saturations postoperatively (86% [interquartile range, 85% to 90%] vs 82% [80% to 85%]; p = 0.001) and had a longer median interval before the total cavopulmonary connection (3.42 [2.43 to 4.89] years vs 2.90 [2.08 to 3.32] years; p = 0.06). At the total cavopulmonary connection, they were older (4.59 [3.88 to 6.49] years vs 3.94 [3.10 to 4.57] years; p = 0.03) and had a larger median body surface area (0.73 [0.65 to 0.87] m(2) vs 0.68 [0.59 to 0.73] m(2); p = 0.04). Conclusions. Patients with a bidirectional cavopulmonary shunt and additional pulmonary blood flow have a longer interval before the total cavopulmonary connection without evident untoward effects. This may theoretically be advantageous for the pulmonary artery growth needed for a successful Fontan circulation. Furthermore, postponement of the final Fontan may ensure the insertion of a larger extracardiac conduit to avoid prosthesis-patient mismatch. (Ann Thorac Surg 2012;93:2028-34) (C) 2012 by The Society of Thoracic Surgeon

Trends in mortality (1975-2011) after one- and two-stage Fontan surgery, including bidirectional Glenn through Fontan completion

OBJECTIVES: Techniques and strategies in the Fontan procedure have evolved over the years, including the evolution from a one-to two-stage procedure. With such adjustments made, attention should shift towards survival analysis, including bidirectional cavopulmonary shunt (BCPS) and interstage mortality. The purpose of this study was to investigate the trends in the overall mortality of all patients who underwent a BCPS or one-stage Fontan procedure at our institution in the period of 1975-2011. METHODS: Using a single-institution, retrospective design, we reviewed the patient records of 203 patients from the University Medical Center Groningen, Netherlands, who underwent a Fontan procedure or a BCPS (with the intention to complete cavopulmonary connection at a second later stage) between 1975 and 2011. Trends in mortality were investigated by comparing survival rates during four consecutive decades (1975-84; 1985-94; 1995-2004; 2005-11), and predictors for mortality were identified. RESULTS: During a mean follow-up of 12 years, survival was 69%. Overall mortality declined significantly during the past decades (P = 0.017). This was driven by a decrease in early mortality (P = 0.016), whereas no changes in late mortality could be demonstrated. Multivariate analyses identified a diagnosis of heterotaxy (P = 0.049) and an atriopulmonary connection type of Fontan circulation (P = 0.015) as independent risk factors for overall mortality. CONCLUSIONS: We demonstrate that, with the inclusion of first-stage and interstage mortality also, overall survival after Fontan procedures improved over time. This improvement, however, is mainly caused by a decline in early mortality. Improvement in long-term survival of patients operated on over the past four decades could not (yet) be demonstrated in this series

Effect of Right Ventricular Outflow Tract Obstruction On Right Ventricular Volumes and Exercise Capacity in Patients With Repaired Tetralogy of Fallot

Patients with tetralogy of Fa not and combined right ventricular outflow tract obstruction (RVOTO) and pulmonary regurgitation (PR) have a less dilated right ventricular (RV) and better RV function compared with patients without RVOTO. It is not known whether RVOTO is associated with improved exercise capacity. We compared cardiac magnetic resonance imaging, echocardiography, and exercise tests in 12 patients with RVOTO (Doppler peak RVOT gradient 30 mm Hg) and 30 patients without RVOTO. RV end-systolic and end-diastolic volumes were smaller in patients with RVOTO compared with patients without RVOTO (50 +/- 16 vs 64 +/- 18 ml/m(2) and 117 +/- 24 vs 135 +/- 28 ml/m(2), respectively) and patients with RVOTO had a higher RV mass (52 +/- 14 vs 42 +/- 11 ml/m(2)),

Quality of Life Among Patients With Congenital Heart Disease After Valve Replacement

Most studies concerning valve replacement in congenital heart disease (CHD) focus on surgical morbidity and mortality. However, with the increased life expectancy of these patients, the focus shifts to quality of life (QOL). The aim of this study was to report and compare the QOL of CHD patients after valve replacement with the general population and to find factors associated with QOL. In a multicenter cross-sectional observational study of adults with CHD, QOL was measured with the RAND-36 questionnaire (a health-related QOL questionnaire, with 8 domains scoring from 0 to 100; higher scores indicate a better QOL). Functional status was measured with exercise capacity testing. Uni- and multivariable linear regression was used to find associations with QOL. In total, 324 patients with CHD and a prosthetic valve were included in this study. CHD patients with a valve replacement scored significantly lower than the general population on the general health, vitality, and social functioning domains (P < 0.05). On the bodily pain domain, they scored significantly higher (less pain) (P < 0.001). Higher NYHA class was associated with a lower QOL for all domains, reflecting the importance of functional capacity. Other variables related to aspects of QOL were age, gender, exercise capacity, and employment status. Adult patients with CHD and a prosthetic valve have lower scores on the QOL domains general health, vitality, and social functioning as compared to the general population. NYHA class was negatively associated with all QOL domains. Health care professionals should be aware of these patterns in counseling patients

Pulmonary Valve Replacement:Twenty-Six Years of Experience With Mechanical Valvar Prostheses

BACKGROUND: Although the thromboembolic risk after pulmonary valve replacement (PVR) with mechanical valves is presumed to be high, recent studies suggest promising short-term and mid-term results. However, large studies reporting long-term mortality and valve-related complications are missing. METHODS: We describe valve-related complications in 66 patients with a mechanical pulmonary valvar prosthesis implanted between 1987 and 2013. RESULTS: Mean follow-up duration was 5.9 ± 4.8 years (median 4.9). Mean age at time of implantation was 35 ± 13 years. The most frequent underlying cardiac diagnosis was tetralogy of Fallot (77%). Valvar thrombosis or pannus was reported in 7 patients (10%) of which 4 in the setting of inadequate anticoagulation or pregnancy. Redo PVR was performed in 6 patients. Freedom from redo PVR in survivors after 5 and 10 years was 96% and 89%, respectively. Survival after 5 and 10 years was 91% and 81%, respectively. Main cause of death was end-stage heart failure. CONCLUSIONS: Success of PVR using mechanical valvar prostheses over 26 years was limited because of valvar thrombosis (often in the setting of pregnancy or incompliance with anticoagulation therapy) or pannus. Performance of mechanical prostheses in the pulmonary position may improve when valvar thrombosis is prevented by patient selection, avoiding mechanical valves in patients at increased risk of valvar thrombosis, and by strict compliance to anticoagulation therapy

Quality of Life Among Patients With Congenital Heart Disease After Valve Replacement

Most studies concerning valve replacement in congenital heart disease (CHD) focus on surgical morbidity and mortality. However, with the increased life expectancy of these patients, the focus shifts to quality of life (QOL). The aim of this study was to report and compare the QOL of CHD patients after valve replacement with the general population and to find factors associated with QOL. In a multicenter cross-sectional observational study of adults with CHD, QOL was measured with the RAND-36 questionnaire (a health-related QOL questionnaire, with 8 domains scoring from 0 to 100; higher scores indicate a better QOL). Functional status was measured with exercise capacity testing. Uni- and multivariable linear regression was used to find associations with QOL. In total, 324 patients with CHD and a prosthetic valve were included in this study. CHD patients with a valve replacement scored significantly lower than the general population on the general health, vitality, and social functioning domains (P < 0.05). On the bodily pain domain, they scored significantly higher (less pain) (P < 0.001). Higher NYHA class was associated with a lower QOL for all domains, reflecting the importance of functional capacity. Other variables related to aspects of QOL were age, gender, exercise capacity, and employment status. Adult patients with CHD and a prosthetic valve have lower scores on the QOL domains general health, vitality, and social functioning as compared to the general population. NYHA class was negatively associated with all QOL domains. Health care professionals should be aware of these patterns in counseling patients

Biological versus mechanical heart valve prosthesis during pregnancy in women with congenital heart disease

Background: We evaluate pregnancy outcome and anticoagulation regimes in women with mechanical and biological prosthetic heart valves (PHV) for congenital heart disease. Methods: Retrospective multicenter cohort studying pregnancy outcomes in an existing cohort of patients with PHV. Results: 52 women had 102 pregnancies of which 78 pregnancies (46 women) ≥20 weeks duration (59 biological, 19 mechanical PHV). Miscarriages (n = 19, ≤20 weeks) occurred more frequently in women using anticoagulation (P <.05). During 42% of pregnancies of women with mechanical PHV a combined low molecular weight heparin (LMWH) vitamin-K-antagonist anticoagulation regime was used (n = 8). Overall, cardiovascular, obstetric and fetal/neonatal complications occurred in 17% (n = 13), 68% (n = 42) and 42% (n = 27) of the pregnancies. Women with mechanical PHV had significantly higher cardiovascular (12% vs 32%, P <.05), obstetric (59% vs 85%, P =.02) and fetal/neonatal (34% vs 61%, P <.05) complication rates than women with biological PHV. This was related to PHV thrombosis (n = 3, P <.02), post-partum hemorrhage (P <.02), cesarean section (P <.02), low birth weight and small for gestational age (both P <.05). PHV thrombosis occurred in 3 pregnancies, including 2/5 pregnancies with pulmonary mechanical PHV. PHV thrombosis was related to necessary cessation of anticoagulation therapy or insufficient monitoring of LMWH. Other cardiovascular complications occurred equally frequent in both groups. Conclusion: Complications occur more often in pregnancies of women with a mechanical PHV than in women with a biological PHV, mainly caused by PHV thrombosis and bleeding complications. Meticulous monitoring of anticoagulation in pregnant women is necessary. Women with a pulmonary mechanical PHV are at high risk of complications

Aortic valve prosthesis-patient mismatch and exercise capacity in adult patients with congenital heart disease

To report the prevalence of aortic valve prosthesis-patient mismatch (PPM) in an adult population with congenital heart disease (CHD) and its impact on exercise capacity. Adults with congenital heart disease (ACHD) with a history of aortic valve replacement may outgrow their prosthesis later in life. However, the prevalence and clinical consequences of aortic PPM in ACHD are presently unknown. From the national Dutch Congenital Corvitia (CONCOR) registry, we identified 207 ACHD with an aortic valve prosthesis for this cross-sectional cohort study. Severe PPM was defined as an indexed effective orifice area ≤0.65 cm2/m2 and moderate PPM as an indexed orifice area ≤0.85 cm2/m2 measured using echocardiography. Exercise capacity was reported as percentage of predicted exercise capacity (PPEC). Of the 207 patients, 68% was male, 71% had a mechanical prosthesis and mean age at inclusion was 43.9 years ±11.4. The prevalence of PPM was 42%, comprising 23% severe PPM and 19% moderate PPM. Prevalence of PPM was higher in patients with mechanical prostheses (p <0.001). PPM was associated with poorer exercise capacity (mean PPEC 84% vs. 92%; p=0.048, mean difference =-8.3%, p=0.047). Mean follow-up was 2.6±1.1 years during which New York Heart Association (NYHA) class remained stable in most patients. PPM showed no significant effect on death or hospitalisation during follow-up (p=0.218). In this study we report a high prevalence (42%) of PPM in ACHD with an aortic valve prosthesis and an independent association of PPM with diminished exercise capacit