The Ross procedure in infants and young children

BACKGROUND: This study reviews our experience with the Ross procedure in infants and young children. METHODS: From September 1993 to September 2004, 52 children less than 15 years of age underwent a Ross procedure. The patients ranged in age from 4 days to 15 years old (median, 5 years). Fifteen patients (29%) were less than 2 years of age. The predominant indication for the Ross procedure was aortic stenosis. Sixteen patients underwent a Ross-Konno procedure for severe left ventricular outflow tract obstruction. Thirty-four patients had 48 previous interventions. Preoperatively, 6 patients showed severe left ventricular dysfunction, and 2 of the patients required ventilation and inotropic support. Concomitant procedures were performed in 8 patients. Three patients had a mitral valve replacement, 2 patients had a ventricular septal defect closure and an aortic arch reconstruction, 2 patients had aortic arch reconstructions, and 1 patient had resection of a coarctation and a ventricular septal defect closure. RESULTS: Patients were followed up for a median of 43 months (range, 1 to 130). Overall survival was 85% +/- 5% at 1 and 82% +/- 5% at 2, 5, and 10 years. Hospital mortality was 5 of 52 patients (9.6%). All deaths occurred in neonates or infants less than 2 months of age, who needed urgent surgery. Three patients died late of noncardiac causes. At last follow-up, all patients were classified in New York Heart Association functional class I or II. No patient had endocarditis of the autograft or the right ventricular outflow tract replacement. During the follow-up, no event of thrombembolism was observed. No patient required the insertion of a permanent pacemaker. Overall freedom from reoperation is 57% +/- 15% at 10 years. One patient required the replacement of the autograft at 6 months postoperatively. The development of mild aortic insufficiency was observed in 24 patients, and moderate aortic insufficiency in 1 patient during follow-up. Freedom from reoperation for the right ventricular outflow tract replacement is 60% +/- 15% at 10 years. CONCLUSIONS: The Ross procedure represents an attractive approach to aortic valve disease in young children. However, a high early mortality rate has to be considered when performing this procedure in neonates or infants who present in critical preoperative condition.

Recent advances in understanding Marfan syndrome: should we now treat surgical patients with losartan?

OBJECTIVE: Marfan syndrome is a systemic connective tissue disorder caused by mutations in the fibrillin-1 gene. It was originally believed that Marfan syndrome results exclusively from the production of abnormal fibrillin-1 that leads to structurally weaker connective tissue when incorporated into the extracellular matrix. This effect seemed to explain many of the clinical features of Marfan syndrome, including aortic root dilatation and acute aortic dissection, which represent the main causes of morbidity and mortality in Marfan syndrome. METHODS: Recent molecular studies, most based on genetically defined mouse models of Marfan syndrome, have challenged this paradigm. These studies established the critical contribution of fibrillin-1 haploinsufficiency and dysregulated transforming growth factor-beta signaling to disease progression. RESULTS: It seems that many manifestations of Marfan syndrome are less related to a primary structural deficiency of the tissues than to altered morphogenetic and homeostatic programs that are induced by altered transforming growth factor-beta signaling. Most important, transforming growth factor-beta antagonism, through transforming growth factor-beta neutralizing antibodies or losartan (an angiotensin II type 1 receptor antagonist), has been shown to prevent and possibly reverse aortic root dilatation, mitral valve prolapse, lung disease, and skeletal muscle dysfunction in a mouse model of Marfan syndrome. CONCLUSION: There are indicators that losartan, a drug widely used to treat arterial hypertension in humans, offers the first potential for primary prevention of clinical manifestations in Marfan syndrome.

Cor triatriatum sinister.

The cor triatriatum sinister is an uncommon congenital cardiac anomaly and reports in the literature are limited. It is often associated with other cardiac malformations, such as atrial septal defect, transposition of the great arteries, tetralogy of Fallot or atrioventricular septal defect. We present here a 6-year old boy who was diagnosed with cor triatriatum sinister, initially showing symptoms similar to mitral valve stenosis and congestive heart failure, and who underwent subsequent surgical correction using a left atrial approach. The fibromuscular membrane, separating the pulmonary veins from the mitral valve, was completely resected and postoperative echocardiography showed unobstructed pulmonary venous flow.

Anaesthetic induction with etomidate in cardiac surgery: A randomised controlled trial.

BACKGROUND Etomidate is perceived as preserving haemodynamic stability during induction of anaesthesia. It is also associated with adrenocortical dysfunction. The risk/benefit relationship is controversial. OBJECTIVES We tested the hypotheses that single-dose etomidate increases cumulative vasopressor requirement, time to extubation and length of stay in the ICU. DESIGN Double-blind randomised controlled trial. SETTING Bern University Hospital, Switzerland, from November 2006 to December 2009. PATIENTS There were 90 patients undergoing coronary artery bypass grafts (CABG) and 40 patients undergoing mitral valve surgery (MVS). Reasons for noninclusion were known adrenocortical insufficiency, use of etomidate or propofol within 1 week preoperatively, use of glucocorticoids within 6 months preoperatively, severe renal or liver dysfunction, or carotid stenosis. INTERVENTIONS CABG patients were allocated randomly to receive either etomidate 0.15 mg kg with placebo, propofol 1.5 mg kg with placebo or etomidate 0.15 mg kg with hydrocortisone (n = 30 in each arm). Risk stratification (low vs. high) was achieved by block randomisation. MVS patients received either etomidate 0.15 mg kg or propofol 1.5 mg kg (n = 20 in each arm). MAIN OUTCOME MEASURES Cumulative vasopressor requirements, incidence of adrenocortical insufficiency, length of time to extubation and length of stay in ICU. RESULTS Cumulative vasopressor requirements 24 h after induction did not differ between treatments in patients who underwent CABG, whereas more noradrenaline was used in MVS patients following propofol induction (absolute mean difference 5.86 μg kg over 24 h P = 0.047). The incidence of relative adrenocortical insufficiency was higher after etomidate alone than propofol (CABG 83 vs. 37%, P < 0.001; MVS: 95 vs. 35%, P < 0.001). The time to extubation, length of stay in ICU and 30-day mortality did not differ among treatments. Within low and high-risk subgroups, no differences in vasopressor use or outcomes were found. CONCLUSION In elective cardiac surgery, laboratory indicators of etomidate-induced adrenal insufficiency do not translate into increased vasopressor requirement or inferior early outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT 00415701.

The association between parity and selected structural birth defects

BACKGROUND: Parity is a risk factor in neonatal morbidity and mortality. This dissertation examined the association between first births and selected birth defects. The first aim was to assess the risk of 66 birth defects among first births and third or greater births. The second aim was to determine if maternal race, maternal age, infant sex or infant birth weight modify the association between first births and selected birth defects. METHODS: The Texas Birth Defects Registry provided data for 1999-2009. For the first aim, odds ratios were calculated for each birth defect. For the second aim, analysis was restricted to the ten birth defects significantly associated with first births. Stratified analyses were conducted and interaction terms were added to logistic regression models to assess whether differences in the odds ratios for the effect of first birth were statistically significant across strata. RESULTS: Findings for the first aim showed that first births had significantly increased odds of having an infant with 24 of the 66 birth defects. Third or greater births had significantly increased odds of having four of the 66 birth defects. For the second aim, a number of significant effect modifiers were observed. For patent ductus arteriosis, obstructive urinary defects and gastroschisis, the effect of first births was significantly modified by black or U.S.-born Hispanic mothers. The effect of first birth was also significantly modified among mothers ≥30 years for mitral valve insufficiency, atrial septal defect and congenital hip dislocation. The effect of first births was significantly modified among infants with low birth weight for hypospadias, congenital hip dislocation and gastroschisis. CONCLUSIONS: First births were associated with an elevated risk of 24 categories of birth defects. For some of the birth defects studied, the effect of first birth is modified by maternal age, maternal race and low birth weight. Knowledge of the increased risk for birth defects among women having their first birth allows physicians and midwives to provide better patient care and spur further research into the etiology of associated birth defects. This knowledge may bring about interventions prior to conception in populations most likely to conceive.^

Chronic renal failure in an English bull terrier with polycystic kidney disease

An entire female English bull terrier, aged five years and one month, was diagnosed with polycystic kidney disease by renal ultrasonography. It had thickening and abnormal motion of the mitral valve on 2D and M mode echocardiography, and left ventricular outflow tract obstruction, characterised by turbulence in the left ventricular outflow tract and elevated aortic blood flow velocity, detected by colour flow and spectral Doppler echocardiography, respectively. Two years later, haematology, serum biochemistry and urinalysis data suggested the presence of compensated renal failure. The dog was euthanased at 10 years and eight months of age, with haematology, serum biochemistry and urinalysis data indicating decompensated chronic renal failure. Postmortem examination confirmed polycystic kidney disease, chronic renal disease, mitral and aortic valvular myxomatous degeneration, and mixed mammary neoplasia. This case demonstrates that bull terriers with polycystic kidney disease may develop associated chronic renal failure.

Melanocytes in the developing and adult atrioventricular valves of the murine heart

The Neural Crest (NC) is a multipotential group of cells that arises from the dorsal aspect of the neural tube early in development. It is well established that a group of NC cells named Cardiac Neural Crest (CNC) migrates to the heart and plays a critical role in the remodeling of the aortic arch arteries and septation of the outflow tract. In this study, using the mouse mutant Pax3sp/sp that has CNC deficits I have identified a putative novel role for the CNC in regulating apoptosis in the atrioventricular (AV) endocardial cushion. The AV endocardial cushion undergoes remodeling to give rise to the cardiac AV valves. Using a transgenic mouse that carries the LacZ reporter gene under the control of the Dopachrome tautomerase promoter (Dct-LacZ), I found that another NC derived population, melanocyte precursors, also contribute to the AV endocardial cushion and developing AV valves. The analysis of Dct-LacZ embryos at different stages showed that NC cells already committed to the melanocytic fate migrate to the heart along the same initial pathway taken by those that will populate the skin. Hypopigmented mice carrying mutations in the Kit and Endothelin receptor b genes, that are critical for the proper development of skin melanocytes, do not have cardiac melanocytes indicating that cardiac and skin melanocyte precursors share the same initial signaling requirements. The analysis of murine adult hearts showed that melanocytes are mostly found in the atrial sides of the tricuspid and mitral valve leaflets. The distribution of melanocytes in the AV valves corresponds exactly to areas of high Versican B expression, a proteoglycan essential for the process of AV valve remodeling. To evaluate a potential role for melanocytes in the AV valves, a nanoindentation analysis of the tricuspid valves of wild type, hypopigmented and hyperpigmented mice was performed. The storage modulus, a measure of stiffness, for the leaflets obtained from hyperpigmented mice was considerably higher (10.5GPa) than that for the leaflets from wild type (7.5GPa) and hypopigmented animals (between 3.5 and 5.5 GPa) suggesting that melanocytes may contribute to the mechanical properties of the AV valves.

Two cases of right atrial myxoma in redo patients. A mere coincidence?

We describe two cases of right atrial myxoma in redo patients who had previously undergone to coronary artery by-pass grafting (CABGs) and mitral valve replacement respectively. Both of patients experienced effort dyspnea and were assessed by trans-thoracic echocardiography, revealing the right atrial masses. They were operated on for myxoma resection and postoperative course was uneventful. Our report deals with the interesting topic of the location of benign masses that are usually more common in the left atrium. Should we hypothesize that the right atrial manipulation during the previous surgery induces the onset of the right atrial mass? It is an interesting matter to debate.

Behind Recurrent Thromboembolic Events

We describe the case of a 68-year-old man, who presented with an ischemic stroke due to cardiac embolization related to mitral valve endocarditis. Blood cultures were always negative and post-operative valve histology did not show microorganisms. The patient also presented further recurrent peripheral embolic events. These clinical aspects were the first sign of a pancreas adenocarcinoma, which was only diagnosed in the clinical autopsy. In conclusion, these clinical findings of recurrent thromboembolic events with no microorganisms isolated suggests the diagnostic of a marantic endocarditis.

Utilizzo pratico e significato clinicopatologico delle frazioni escrete degli elettroliti nel riconoscimento del danno renale acuto (AKI) in diversi setting clinici

Ricerche nel campo del danno renale acuto e frazioni urinarie escrete. La prima parte verte sull’analisi dei dati provenienti da una casistica di cani con leptospirosi, sono stati confrontati due gruppi di cani, il primo con AKI da leptospirosi e l’altro con AKI per eziologie differenti. In queste due popolazioni di pazienti abbiamo valutato alcuni analiti sierici ed urinari come ad esempio l’escrezione elettrolitica frazionata e biomarker di AKI come NGAL. I cani con leptospirosi, hanno mostrato maggiore kaliuresi e più grave glicosuria rispetto a quelli non affetti da leptospirosi, così come erano più frequentemente glicosurici rispetto agli altri. Questi dati sono in analogia con quanto è riportato nell’uomo e dimostrano un pattern di danno tubulare tipico in corso di questa malattia se paragonato appunto ad altre cause di danno tubulare acuto e AKI La seconda parte riguarda la valutazione della funzionalità renale e del danno renale acuto in cani affetti da insufficienza valvolare mitralica. E’ stata incentrata sul danno renale in corso di cardiopatie e per questa ragione abbiamo pensato di valutare esclusivamente pazienti con MVD per varie ragioni: poiché sono pazienti che si presentano frequentemente nella pratica clinica; la malattia è tipicamente cronica e il paziente rimane stabile a lungo con un andamento progressivo della malattia; questi pazienti possono presentare frequenti episodi di AKI legati allo scompenso cardiaco e/o alla terapia con diuretico 3/o ace-i che questi animali ricevono. Abbiamo valutato prospetticamente l'impatto della terapia orale con furosemide sulla chimica urinaria, nei cani con malattia della valvola mitrale mixomatosa. Tali differenze sono state attribuite all'effetto della terapia con furosemide sugli elettroliti renali. La chimica urinaria è utile per stimare la risposta diuretica nei cani con malattie cardiache. I dati suggeriscono differenze significative tra i diversi stadi ACVIM con particolare riferimento all’escrezione elettrolitica di Sodio, Potassio e Cloro.

Impact of mitral regurgitation on clinical outcomes of patients with low-ejection fraction, low-gradient severe aortic stenosis undergoing transcatheter aortic valve implantation.

BACKGROUND Up to 1 in 6 patients undergoing transcatheter aortic valve implantation (TAVI) present with low-ejection fraction, low-gradient (LEF-LG) severe aortic stenosis and concomitant relevant mitral regurgitation (MR) is present in 30% to 55% of these patients. The effect of MR on clinical outcomes of LEF-LG patients undergoing TAVI is unknown. METHODS AND RESULTS Of 606 consecutive patients undergoing TAVI, 113 (18.7%) patients with LEF-LG severe aortic stenosis (mean gradient ≤40 mm Hg, aortic valve area <1.0 cm(2), left ventricular ejection fraction <50%) were analyzed. LEF-LG patients were dichotomized into ≤mild MR (n=52) and ≥moderate MR (n=61). Primary end point was all-cause mortality at 1 year. No differences in mortality were observed at 30 days (P=0.76). At 1 year, LEF-LG patients with ≥moderate MR had an adjusted 3-fold higher rate of all-cause mortality (11.5% versus 38.1%; adjusted hazard ratio, 3.27 [95% confidence interval, 1.31-8.15]; P=0.011), as compared with LEF-LG patients with ≤mild MR. Mortality was mainly driven by cardiac death (adjusted hazard ratio, 4.62; P=0.005). As compared with LEF-LG patients with ≥moderate MR assigned to medical therapy, LEF-LG patients with ≥moderate MR undergoing TAVI had significantly lower all-cause mortality (hazard ratio, 0.38; 95% confidence interval, 0.019-0.75) at 1 year. CONCLUSIONS Moderate or severe MR is a strong independent predictor of late mortality in LEF-LG patients undergoing TAVI. However, LEF-LG patients assigned to medical therapy have a dismal prognosis independent of MR severity suggesting that TAVI should not be withheld from symptomatic patients with LEF-LG severe aortic stenosis even in the presence of moderate or severe MR.

Relationship of ventricular longitudinal function to contractile reserve in patients with mitral regurgitation

Background Latent left ventricular (LV) dysfunction in patients with valvular or myocardial disease may be identified by loss of contractile reserve (CR) at exercise echocardiography. Contraction in the LV longitudinal axis may be more sensitive than radial contraction to minor disturbances of LV function. We sought to determine whether tissue Doppler measurement of longitudinal function could be used to identify CR. Methods Exercise echocardiography was performed in 86 patients (20 women, age 53 +/- 18 years), 72 with asymptomatic or minimally symptomatic mitral regurgitation, and 14 normal controls. Pulsed-wave tissue Doppler imaging (DTI) was used to measure maximum annular systolic velocity at rest and stress. Inducible ischemia was excluded by analysis of wall motion by an experienced observer. CR was defined by greater than or equal to5% improvement of stress compared with rest ejection fraction (EF). Exercise capacity was assessed from expired gas analysis. Results CR was present in 34 patients with mitral regurgitation (47%); peak EF in patients with and without CR was 74% +/- 11% versus 54% +/- 15% (P