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)

Pulmonary regurgitant volume is superior to fraction using background-corrected phase contrast MRI in determining the severity of regurgitation in repaired tetralogy of Fallot

In the assessment of pulmonary regurgitation (PR) using phase contrast MRI, phase offset errors affect the accuracy of flow. This study evaluated the use of automated background correction for phase offset in the quantification of PR fraction and volume in patients with repaired tetralogy of Fallot (TOF), and to assess its clinical impact. We retrospectively analyzed 203 cardiac MRI studies, performed on 1.5-T scanner. Pulmonary flow (Q(P)) and systemic flow (Q(S)) was assessed both with and without background correction. Non-corrected and corrected Q(P) was correlated with Q(S). PR was correlated with (1) indexed right ventricular end-diastolic volume (RVEDVi) and (2) with differential right and left ventricular stroke volumes (PRSV). Both PR fraction and volume showed major change after correction (-43 to +36 % and -13 to +13 ml/m(2)). Corrected Q(P) and Q(S) were stronger correlated with each other than non-corrected Q(P) and Q(S) [r = 0.78 vs. 0.73 (p <0.001)]. Both PR fraction and volume were stronger correlated with RVEDVi, compared to their non-corrected counterparts (p <0.001). PR volume was stronger correlated with RVEDVi, compared to PR fraction [r = 0.74 vs. 0.69 (p <0.001)]. When patients were divided according to PR severity, 12 % of patients reclassified after correction. Background correction for phase offset significantly changed the quantification of PR. Non-corrected assessment of PR may result in the misclassification of patients. Our data suggest that the use of PR volume is favourable in the follow-up of patients with repaired TOF

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)),

End-systolic and end-diastolic frame selection of the right ventricle compared to the left ventricle.

<p>LV = left ventricle, RV = right ventricle, ToF = tetralogy of Fallot.</p

Right ventricular volumes measured in the end-systolic and end-diastolic frame of the left and right ventricle.

<p>EDV = end-diastolic volume, EF = ejection fraction, ESV = end-systolic volume, IQR = interquartile range, LV = left ventricle, RV = right ventricle, SD = standard deviation, SV = stroke volume, ToF = tetralogy of Fallot.</p

Change in right ventricular volumes and function.

<p>Scatterplots of the change in RV end-systolic volume (<b>A</b>), end-diastolic volume (<b>B</b>) and ejection fraction (<b>C</b>) when using the end-systolic and end-diastolic frame of the RV instead of the LV. EDV = end-diastolic volume, EF = ejection fraction, ESV = end-systolic volume, LV = left ventricular, RBBB = right bundle branch block, RV = right ventricular, ToF = tetralogy of Fallot.</p

Example of the left and right end-systolic frame and the corresponding time-volume curve.

<p>Two short axis images of the end-systolic frame of the LV (<b>A</b>) and RV (<b>B</b>), and the corresponding time-volume curve (<b>C</b>) in a patient with ToF and a complete RBBB. Timing of the RV end-systolic frame is 106 ms (3 frames) delayed compared to LV end-systolic frame. Measuring the RV end-systolic volume in the LV instead of the RV end-systolic frame results in a difference of 9 ml/m². This is visible in the short-axis image of the RV end-systolic frame (<b>B</b>) in which the larger blue contour corresponds to the RV contour of the LV end-systolic frame (<b>A</b>) and the yellow contour to the RV contour of the RV end-systolic frame. Timing of the end-diastolic frame is the same for the RV and LV. LV = left ventricle, Max. = maximum volume, Min. = minimal volume, RBBB = right bundle branch block, RV = right ventricle.</p

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