Unravelling early sinus node dysfunction after pediatric cardiac surgery: a pre-existing arrhythmogenic substrate.

Early post-operative sinus node dysfunction (SND) is common in paediatric patients undergoing surgical correction of congenital heart defects (CHD). At present, the pathophysiology of these arrhythmias is incompletely understood. In this case series, we present three paediatric patients in whom we performed intraoperative epicardial mapping and who developed early post-operative SND. All patients had either an inferior or multiple sinoatrial node (SAN) exit sites, in addition to extensive conduction disorders at superior and inferior right atrium. Our findings contribute to the hypothesis that pre-existing alterations in SAN exit sites in combination with atrial conduction disorders may predispose paediatric patients with CHD for early post-operative SND. Such insights in the development of arrhythmias are crucial as it may be the first step in identifying high-risk patients.

Native valve, prosthetic valve, and cardiac device-related infective endocarditis: A review and update on current innovative diagnostic and therapeutic strategies.

Infective endocarditis (IE) is a life-threatening microbial infection of native and prosthetic heart valves, endocardial surface, and/or indwelling cardiac device. Prevalence of IE is increasing and mortality has not significantly improved despite technological advances. This review provides an updated overview using recent literature on the clinical presentation, diagnosis, imaging, causative pathogens, treatment, and outcomes in native valve, prosthetic valve, and cardiac device-related IE. In addition, the experimental approaches used in IE research to improve the understanding of disease mechanisms and the current diagnostic pipelines are discussed, as well as potential innovative diagnostic and therapeutic strategies. This will ultimately help towards deriving better diagnostic tools and treatments to improve IE patient outcomes.

In-vivo Sino-Atrial Node Mapping in Children and Adults With Congenital Heart Disease.

Background: Sinus node dysfunction (SND) and atrial tachyarrhythmias frequently co-exist in the aging patient with congenital heart disease (CHD), even after surgical correction early in life. We examined differences in electrophysiological properties of the sino-atrial node (SAN) area between pediatric and adult patients with CHD. Methods: Epicardial mapping of the SAN was performed during sinus rhythm in 12 pediatric (0.6 [0.4-2.4] years) and 15 adult (47 [40-55] years) patients. Unipolar potentials were classified as single-, short or long double- and fractionated potentials. Unipolar voltage, relative R-to-S-amplitude ratio and duration of all potentials was calculated. Conduction velocity (CV) and the amount of conduction block (CB) was calculated. Results: SAN activity in pediatric patients was solely observed near the junction of the superior caval vein and the right atrium, while in adults SAN activity was observed even up to the middle part of the right atrium. Compared to pediatric patients, the SAN region of adults was characterized by lower CV, lower voltages, more CB and a higher degree of fractionation. At the earliest site of activation, single potentials from pediatrics consisted of broad monophasic S-waves with high amplitudes, while adults had smaller rS-potentials with longer duration which were more often fractionated. Conclusions: Compared to pediatric patients, adults with uncorrected CHD have more inhomogeneous conduction and variations in preferential SAN exit site, which are presumable caused by aging related remodeling. Long-term follow-up of these patients is essential to demonstrate whether these changes are related to development of SND and also atrial tachyarrhythmias early in life.

First-in-children epicardial mapping of the heart: unravelling arrhythmogenesis in congenital heart disease.

Patients with congenital heart disease (CHD) are prone to develop atrial and ventricular arrhythmias. Multiple factors throughout life contribute to arrhythmogenicity substrate such as (i) (longstanding) volume and/or pressure overload, (ii) scar tissue, (iii) ageing-related structural remodelling, (iv) cardiovascular risk factors and (v) tachycardia-induced remodelling. At present, it is unknown whether, and to what extent, paediatric patients with CHD have atrial or ventricular conduction disorders early in life and whether there is a correlation between duration of volume/pressure overload and extensiveness of conduction disorders. To investigate this, we initiated high-resolution intraoperative epicardial mapping in paediatric patients with CHD undergoing primary open-heart surgery.

First Evidence of Atrial Conduction Disorders in Pediatric Patients With Congenital Heart Disease.

This study sought to investigate whether pediatric patients with congenital heart disease (CHD) already have atrial conduction disorders early in life. The authors conducted first-in-children epicardial mapping in 10 pediatric patients with CHD undergoing primary open heart surgery. Areas of conduction delay (CD) and block (CB) were present in all patients and were particularly observed at Bachmann's bundle (CD: 4.9%; CB: 2.3%), followed by the right atrium (CD: 3.7%; CB: 1.6%) and, to a lesser degree, the left atrium (CD: 1.8%; CB: 1.0%). Conduction abnormalities may by aggravated over time (e.g., aging, residual lesions, or valvular dysfunction), predisposing these patients to atrial arrhythmias early in life.

Echocardiographic and clinical outcome after mitral valve plasty with a minimal access or conventional sternotomy approach.

BACKGROUND: The aim of this study is to evaluate the effects of minimal access mitral valve surgery (MAMVS) versus conventional surgery with or without concomitant tricuspid valve plasty (TVP) in consecutive patients with mitral regurgitation (MR) on clinical and echocardiographic outcome. METHODS: One-hundred-and-twenty patients operated for MR (91 conventional and 29 MAMVS) were followed by echocardiography and quality of life assessment before and 6 months after surgery. RESULTS: Patients in the MAMVS group were younger, more often in NYHA functional class I-II and had lower NT-proBNP levels. Only four patients (all in the conventional group) underwent mitral valve replacement. There were no significant differences in complications between MAMVS and conventional surgery. At 6 months, comparable MR reduction and left ventricular remodeling data were seen, left atrial remodeling was most prominent in the MAMVS group, 71 [55-90] to 43 [35-58] versus 69 [53-89] to 49 [41-70] mL/m2 in the conventional group (P<0.05). Significant improvement for all quality of life domains were seen, except for pain, with no intergroup differences. Twenty-seven (23%) patients underwent concomitant TVP, all in the conventional group. Tricuspid regurgitation decreased after concomitant TVP (P<0.001), whereas in patients with no TVP no significant changes occurred. At 6 months tricuspid regurgitation grade was comparable in patients with TVP versus patients without need for TVP. CONCLUSIONS: MR severity reduced significantly, with no difference between conventional surgery and MAMVS in reducing MR, with superior left atrial remodeling in the MAMVS group. In-hospital complications and NYHA class and quality of life assessment were not different between conventional surgery and MAMVS.

Influence of pregnancy on long-term durability of allografts in right ventricular outflow tract.

BACKGROUND: There is very limited published evidence about the influence of pregnancy on allograft durability in right ventricular outflow tract position. We present the first study using mixed and joint modeling. METHODS: This retrospective study compared clinical and valve related outcomes of all consecutive female hospital survivors in their fertile life phase (18-50 years) based on pregnancy. Serial echocardiographic measurements of pulmonary gradient and regurgitation were analyzed for their association with valve replacement using joint models for longitudinal and time-to-event data. Occurrence of first pregnancy was included as a time-dependent intermediate event in both the longitudinal and survival analyses of the joint model to assess its impact on the hemodynamic and clinical outcome. RESULTS: In total, 196 consecutive women in their fertile life-phase with an allograft were included. Complete information of 176 (90%) allografts in 165 women was available, including 1395 echocardiograms. Of these women, 51 (30.9%) women had 84 completed pregnancies at an average age of 29.1 ± 3.9 (SD) years; 8.1 ± 6.1 years since allograft implantation. Tetralogy of Fallot was the most common diagnosis in both groups. After a mean follow-up of 15.2 years (range 0.1-30), 7 (13.7%) parous women underwent valve replacement versus 20 (17.5%) nulliparous women. During this follow-up, the mean allograft gradient in parous (24.2 mm Hg) and nulliparous (21.0 mm Hg) women was comparable (P = .225). A 1-mm Hg increase in pulmonary gradient increased the instantaneous risk of pulmonary valve replacement (PVR) by a ratio of 1.051 (P < .001), regardless of pregnancy. Similarly, development of moderate or severe regurgitation increased the risk of PVR (P = .038), regardless of pregnancy. Pregnancy was not associated with a change in the allograft gradient (P = .258), regurgitation grade (P = .774), or hazard of PVR (P = .796) during follow-up. CONCLUSIONS: Pregnancy is not associated with impaired allograft durability in women with good cardiac health.

A case report on endarteritis in a child with coarctation of aorta.

Coarctation of aorta(CoA), complicated by endarteritis in a children is very rare. Here we present a case of endarteritis in an unoperated CoA in a four year old boy. CoA had been diagnosed in the referring hospital, yet the diagnosis of endocarditis distal to CoA, was made in the tertiary center using modified transthoracic echo windows or focused views. After six weeks of intravenous antibiotic treatment, a coarctectomy and end-to-end anastomosis was performed and he recovered clinically well. This case report concludes that echocardiography remains as the standard diagnostic method for identifying intracardiac manifestations of infective endocarditis/endarteritis. Last but foremost, it delineates the importance of modified transthoracic echo windows or focused views in identifying the unusual position of endocarditis.

Outcomes of Pregnancy After Right Ventricular Outflow Tract Reconstruction With an Allograft Conduit.

BACKGROUND: There is no published evidence on pregnancy after right ventricular outflow tract (RVOT) reconstruction with an allograft. OBJECTIVES: The aim of this study was to describe pregnancy outcomes in women with allografts in the RVOT position. METHODS: A retrospective cohort study of consecutive female patients who received allografts in the RVOT position was conducted. All patients between 18 and 50 years of age were screened for cardiac, obstetric, and fetal outcomes of completed (≥20 weeks' gestation) pregnancies. RESULTS: In total, 196 women met the inclusion criteria, of whom 56 had 89 completed pregnancies. Information could be retrieved in 84 cases (94.4%). Mean maternal age was 29.6 ± 4.3 years, with 80 patients (95.2%) in New York Heart Association functional class I or II. The most common diagnosis was tetralogy of Fallot. All women survived pregnancy. There were 2 cases (2.4%) of heart failure (arrhythmic and diastolic dysfunction), 1 case (1.2%) of infection (chorioamnionitis), and 3 cases (3.6%) of pre-eclampsia. No other cardiac or obstetric events were reported. All children were born alive at a median gestational age of 38.4 weeks (interquartile range: 36.9 to 39.6 weeks), with a median birthweight of 2,930 g (interquartile range: 2,535 to 3,385 g). Seventeen (20.2%) were small for gestational age, and 20 (23.8%) were premature. Neonatal death was reported in 2 children (2.5%). Preconception pulmonary regurgitation was associated with an increased probability of pre-term labor (odds ratio: 2.610; 95% confidence interval: 1.318 to 5.172). Compared with the general Dutch population, pre-term delivery (25.0% vs. 7.4%, p < 0.001) and children small for gestational age (20.2% vs. 10.0%, p = 0.002) were more common. CONCLUSIONS: Women in good cardiac health after RVOT reconstruction with allografts can safely experience pregnancy and labor. The higher incidence of pre-term delivery and children small for gestational age warrants special attention.

Single-centre experience with mitral valve repair in asymptomatic patients with severe mitral valve regurgitation.

OBJECTIVES: Guidelines recommend surgical mitral valve repair in selected patients with asymptomatic severe mitral valve regurgitation (MR), but the role of repair remains a matter of debate. Survival analyses of operated asymptomatic patients have been reported, but long-term haemodynamics and quality of life are not well defined. The aim of this study was to report the long-term follow-up focusing on these aspects. METHODS: Our database identified patients who underwent primary isolated mitral valve repair for severe MR and were asymptomatic by New York Heart Association Class I and in sinus rhythm. To obtain sufficient length of follow-up, only patients operated on before 2006 returned for an echocardiogram and quality-of-life assessment (SF-36). RESULTS: Between May 1991 and December 2005, 46 asymptomatic patients with severe MR and a normal left ventricular function (ejection fraction >60%) were operated on. Mean age was 50.2 ± 13.2 years and 89% of patients were male. There were no operative deaths. Mean follow-up was 8.4 ± 3.9 years with 386 patient-years, survival was 93.3% at 12 years and comparable with the general age-matched Dutch population. Follow-up echocardiography showed that 92% had no to mild MR, and 3 patients had moderate MR. Left ventricular function was good/impaired/moderate in 66/29/5% of patients. Quality-of-life SF-36 assessment showed that mean physical and mental health components were 83 ± 17 and 79 ± 17, which was comparable with that of the general age- and gender-matched Dutch population. CONCLUSIONS: Our experience shows that mitral valve repair for severe MR in asymptomatic patients is safe, and has satisfactory long-term survival with a low recurrence rate of MR, good left ventricular function, and excellent quality of life that is comparable with the general Dutch population.

Acute dehiscence of a valve prosthesis 5 years after implantation.

Propionibacterium acnes, a common human skin organism [Perry A.L., Lambert P.A., Under the microscope Propionibacterium acnes, Lett App Microbiol 2006; 42:185-186], mostly considered a contaminant, has rarely been associated with cases of infectious endocarditis [Vanagt W.Y., Daenen W.J., Delhaas T., Propionibacterium acnes endocarditis on an annuloplasty ring in an adolescent boy, Heart 2004; 90:56]. We report on a 48-year old man with a history of mitral valve replacement who acutely developed dyspnoea, tachypnoea and forward failure. Transesophageal echocardiography showed a dehiscence of the St. Jude mechanical mitral prosthesis necessitating urgent surgery. The prosthesis was replaced by another St. Jude mechanical valve. Blood cultures were initially negative but after a prolonged incubation period the tissue cultures became positive for Propionibacterium acnes. In cases of valvular dehiscence without macroscopic signs of endocarditis, communication between clinicians and the laboratory is important in order to incubate blood and tissue samples for a longer period of time to be able to detect exceptional causes of endocarditis.