Impact of fetal cardiac intervention on congenital heart surgery

Fetal cardiac interventions performed by interventional cardiologists are currently in a clinical experimental phase. The 3 most frequent interventions are: 1) aortic balloon valvuloplasty for critical aortic stenosis with a small left ventricle or with a normal size left ventricle but poor function; 2) atrial septostomy for highly restrictive or intact atrial septum in hypoplastic left heart syndrome; and 3) pulmonary valvuloplasty for pulmonary atresia and hypoplastic right ventricle. Current impact on everyday congenital heart surgery practice is small, but may increase in the future.     

Diversity of congenital cardiac defects and skeletal deformities associated with the Holt–Oram syndrome

INTRODUCTION

The Holt–Oram syndrome is a rare congenital disorder involving the skeletal and cardiovascular systems. It is characterized by upper limb deformities and cardiac malformations, atrial septal defects in particular.

PRESENTATION OF CASE

Four consecutive patients 1–15 years old with the Holt–Oram syndrome presented over a 10 year span for surgical treatment of their cardiac maladies. The spectrum of the heart defects and skeletal deformities encountered in these patients are described and discussed.

DISCUSSION

The Holt–Oram syndrome is an autosomal dominant condition; however absence of the morphological features of the trait in close family members is not rare. Although patients are known to predominately present with atrial septal defects, other cardiovascular anomalies, including rhythm abnormalities, are not uncommon. Skeletal disorders vary as well.

CONCLUSION

Cardiovascular disorders, skeletal malformations and familial expression of the Holt–Oram syndrome, vary widely.     

Abnormal heart rate variability and atrial fibrillation after aortic surgery

Introduction

Complete denervation of transplanted heart exerts protective effect against postoperative atrial fibrillation; various degrees of autonomic denervation appear also after transection of ascending aorta during surgery for aortic aneurysm.

Objective

This study aimed to evaluate if the level of cardiac denervation obtained by resection of ascending aorta could exert any effect on postoperative atrial fibrillation incidence.

Methods

We retrospectively analysed the clinical records of 67 patients submitted to graft replacement of ascending aorta (group A) and 132 with aortic valve replacement (group B); all episodes of postoperative atrial fibrillation occurred during the 1-month follow-up have been reported. Heart Rate Variability parameters were obtained from a 24-h Holter recording; clinical, echocardiographic and treatment data were also evaluated.

Results

Overall, 45% of patients (group A 43%, group B 46%) presented at least one episode of postoperative atrial fibrillation. Older age (but not gender, abnormal glucose tolerance, ejection fraction, left atrial diameter) was correlated with incidence of postoperative atrial fibrillation. Only among a subgroup of patients with aortic transection and signs of greater autonomic derangement (heart rate variability parameters below the median and mean heart rate over the 75^th percentile), possibly indicating more profound autonomic denervation, a lower incidence of postoperative atrial fibrillation was observed (22% vs. 54%).

Conclusion

Transection of ascending aorta for repair of an aortic aneurysm did not confer any significant protective effect from postoperative atrial fibrillation in comparison to patients with intact ascending aorta. It could be speculated that a limited and heterogeneous cardiac denervation was produced by the intervention, creating an eletrophysiological substrate for the high incidence of postoperative atrial fibrillation observed.     

Fetal heart assessment in the first trimester of pregnancy: influence of crown-rump length and maternal body mass index

Objective

To evaluate the influence of the crown-rump length and body mass index on sonographic evaluation of the fetal heart using abdominal and vaginal routes in the first trimester of pregnancy.

Methods

We conducted a cross-sectional study with 57 pregnant women between 12-14 weeks (CRL≤ 84 mm). We evaluated the following fetal cardiac plans using the abdominal and vaginal routes: four-chamber view, right ventricle outflow tract, left ventricle outflow tract and aortic arch. We used the B-mode, color Doppler and four-dimensional ultrasonography (spatio-temporal image correlation). To evaluate the influence of crown-rump length and body mass index in the assessment of fetal cardiac planes, we used the t test unpaired.

Results

There were no statistically significant differences in the rates of success and failure between abdominal and vaginal routes in relation to body mass index, however, there was a higher failure rate in vaginal assessment using B mode associated with color Doppler (P<0.01).

Conclusion

The crown-rump length and body mass index had no interference in fetal cardiac assessment in the first trimester of pregnancy.     

Information technology implementing globalization on strategies for quality care provided to children submitted to cardiac surgery: International Quality Improvement Collaborative Program - IQIC

Introduction

Congenital heart diseases are the world''s most common major birth defect, affecting one in every 120 children. Ninety percent of these children are born in areas where appropriate medical care is inadequate or unavailable.

Objective

To share knowledge and experience between an international center of excellence in pediatric cardiac surgery and a related program in Brazil.

Methods

The strategy used by the program was based on long-term technological and educational support models used in that center, contributing to the creation and implementation of new programs. The Telemedicine platform was used for real-time monthly broadcast of themes. A chat software was used for interaction between participating members and the group from the center of excellence.

Results

Professionals specialized in care provided to the mentioned population had the opportunity to share to the knowledge conveyed.

Conclusion

It was possible to observe that the technological resources that implement the globalization of human knowledge were effective in the dissemination and improvement of the team regarding the care provided to children with congenital heart diseases.     

Comparison of fractal dimension and Shannon entropy in myocytes from rats treated with histidine-tryptophan-glutamate and histidine-tryptophan cetoglutarate

Introduction

Solutions that cause elective cardiac arrest are constantly evolving, but the ideal compound has not yet been found. The authors compare a new cardioplegic solution with histidine-tryptophan-glutamate (Group 2) and other one with histidine-tryptophan-cetoglutarate (Group 1) in a model of isolated rat heart.

Objective

To quantify the fractal dimension and Shannon entropy in rat myocytes subjected to cardioplegia solution using histidine-tryptophan with glutamate in an experimental model, considering the caspase markers, IL-8 and KI-67.

Methods

Twenty male Wistar rats were anesthetized and heparinized. The chest was opened, the heart was withdrawn and 40 ml/kg of cardioplegia (with histidine-tryptophan-cetoglutarate or histidine-tryptophan-glutamate solution) was infused. The hearts were kept for 2 hours at 4ºC in the same solution, and thereafter placed in the Langendorff apparatus for 30 min with Ringer-Locke solution. Analyzes were performed for immunohistochemical caspase, IL-8 and KI-67.

Results

The fractal dimension and Shannon entropy were not different between groups histidine-tryptophan-glutamate and histidine-tryptophan-acetoglutarate.

Conclusion

The amount of information measured by Shannon entropy and the distribution thereof (given by fractal dimension) of the slices treated with histidine-tryptophan-cetoglutarate and histidine-tryptophan-glutamate were not different, showing that the histidine-tryptophan-glutamate solution is as good as histidine-tryptophan-acetoglutarate to preserve myocytes in isolated rat heart.     

Predictors of stroke in patients undergoing cardiac surgery

Objective

To determine the risk factors related to the development of stroke in patients undergoing cardiac surgery.

Methods

A historical cohort study. We included 4626 patients aged > 18 years who underwent coronary artery bypass surgery, heart valve replacement surgery alone or heart valve surgery combined with coronary artery bypass grafting between January 1996 and December 2011. The relationship between risk predictors and stroke was assessed by logistic regression model with a significance level of 0.05.

Results

The incidence of stroke was 3% in the overall sample. After logistic regression, the following risk predictors for stroke were found: age 50-65 years (OR=2.11 - 95% CI 1.05-4.23 - P=0.036) and age >66 years (OR=3.22 - 95% CI 1.6-6.47 - P=0.001), urgent and emergency surgery (OR=2.03 - 95% CI 1.20-3.45 - P=0.008), aortic valve disease (OR=2.32 - 95% CI 1.18-4.56 - P=0.014), history of atrial fibrillation (OR=1.88 - 95% CI 1.05-3.34 - P=0.032), peripheral artery disease (OR=1.81 - 95% CI 1.13-2.92 - P=0.014), history of cerebrovascular disease (OR=3.42 - 95% CI 2.19-5.35 - P<0.001) and cardiopulmonary bypass time > 110 minutes (OR=1.71 - 95% CI 1.16-2.53 - P=0.007). Mortality was 31.9% in the stroke group and 8.5% in the control group (OR=5.06 - 95% CI 3.5-7.33 - P<0.001).

Conclusion

The study identified the following risk predictors for stroke after cardiac surgery: age, urgent and emergency surgery, aortic valve disease, history of atrial fibrillation, peripheral artery disease, history of cerebrovascular disease and cardiopulmonary bypass time > 110 minutes.     

Pediatric and congenital heart transplant: twenty-year experience in a tertiary Brazilian Hospital

Introduction

Cardiac transplantation remains the gold standard for end-stage cardiomyopathies and congenital heart defects in pediatric patients.

Objective

This study aims to report on 20 years of experience since the first case and evaluate our results.

Methods

We conducted a retrospective analysis of the database and outpatient follow-up. Between October 1992 and April 2012, 109 patients underwent 114 transplants. 51.8% of them being female. The age of patients ranged from 12 days to 21 years with a mean of 8.8±5.7 years and a median of 5.2 years. The underlying diagnosis was dilated cardiomyopathy in 61.5%, congenital heart disease in 26.6% and restrictive cardiomyopathy in 11.9%. All patients above 17 years old had congenital heart disease.

Results

Survival rate at 30 days, 1, 5, 10, 15, and 20 years were 90.4%, 81.3%, 70.9%, 60.5%, 44.4% and 26.7%, respectively. Mean cold ischemic time was 187.9 minutes and it did not correlate with mortality (P>0.05). Infectious complications and rejection episodes were the most common complications (P<0.0001), occurring, respectively, in 66% and 57.4% of the survivors after 10 years. There was no incidence of graft vascular disease and lymphoproliferative disease at year one, but they affected, respectively, 7.4% and 11% of patients within 10 years.

Conclusion

Twenty-year pediatric heart transplant results at our institution were quite satisfactory and complication rates were acceptable.     

Horizontal right axillary minithoracotomy: aesthetic and effective option for atrial and ventricular septal defect repair in infants and toddlers

Introduction

Congenital heart defects treatment shows progressive reduction in morbidity and mortality, however, the scar, resulting from ventricular (VSD) and atrial septal defect (ASD) repair, may cause discomfort. Right axillary minithoracotomy approach, by avoiding the breast growth region, is an option for correction of these defects that may provide better aesthetic results at low cost. Since October 2011, we have been using this technique for repairing VSD and ASD defects as well as associated defects.

Objectives

To evaluate the efficacy of this method in children undergoing correction of VSD and ASD, to compare perioperative clinical outcomes with those repaired by median sternotomy, and to evaluate the aesthetic result.

Methods

Perioperative clinical data of 25 patients submitted to axillary thoracotomy were compared with data from a paired group of 25 patients with similar heart defects repaired by median sternotomy, from October 2011 to August 2012.

Results

Axillary approach was possible even in infants. There was no mortality and the main perioperative variables were similar in both groups, except for lower use of blood products in the axillary group (6/25) vs. control (13/25), with statistical difference (P =0.04). The VSD size varied from 7 to 15 mm in axillary group. Cannulation of the aorta and vena cavae was performed through the main incision, whose size ranged from 3 to 5 cm in the axillary group, with excellent aesthetic results.

Conclusion

The axillary thoracotomy was effective, allowing for a heart defect repair similar to the median sternotomy, with more satisfactory aesthetic results and reduced blood transfusion, and it can be safely used in infants.     

High postoperative serum levels of surfactant type B as novel prognostic markers for congenital heart surgery

Objective

Congenital heart diseases are observed in 5 to 8 of every 1000 live births. The presence of a valuable biomarker during the surgical periods may aid the clinician in a more accurate prognosis during treatment.

Methods

For this reason, surfactant protein B plasma levels may help to evaluate patients with cardiac problems diminishing the alveolocapillary membrane stability. In this study, plasma levels of this biomarker were measured in the preoperative and postoperative periods. This study was conducted to detect the differences between pulmonary hypertensive and normotensive patients. The differences before and after cardiopulmonary bypass were examined.

Results

The differences in cardiopulmonary bypass time, cross-clamp time , inotropic support dose, and duration of intensive care of patients with and without pulmonary hypertensive were found to be statistically significant (P<0.05). The results revealed that this pathophysiological state was related to other variables that were studied. We believe that the differences in preoperative and postoperative SPB levels could be attributed to alveolocapillary membrane damage and alveolar surfactant dysfunction. We found that this pathophysiological condition was significantly associated with postoperative parameters.

Conclusion

The findings of the current study showed that surfactant protein B was present in the blood of patients with a congenital heart disease during the preoperative period. Long by-pass times may exert damage to the alveolocapillary membrane in patients with pulmonary hypertension and preoperative heart failure, and it is recommended to keep the option of surfactant therapy in mind during the postoperative course at the intensive care unit before preparing the patients for extubation.     

Transcatheter aortic valve implantation with balloonexpandable valve: early experience from China

Objective

The aim of the current study was to evaluate the early experience of the application of transcatheter aortic valve implantation with the balloon-expandable system in China. The transcatheter aortic valve implantation technology has been widely used for patients with inoperable severe aortic stenosis in the developed world. The application of transcatheter aortic valve implantation is still in the early stages of testing in China, particularly for the balloon-expandable valve procedure.

Methods

This was a retrospective study. All patients undergoing transcatheter aortic valve implantation with balloon-expandable system in our hospital between 2011 and 2014 were included. Edwards SAPIEN XT Transcatheter Heart Valve was used. The improvement of valve and heart function was evaluated as well as 30-day mortality and major complications according to the VARC-2 definition.

Results

A total of 10 transcatheter aortic valve implantation procedures with the balloon-expandable system were performed in our hospital, of which 9 were transfemoral and 1 was transapical. The median age was 76 years, and the median STS score and Logistic EuroSCORE (%) were 8.9 and 16.2. The implantation was successfully conducted in all patients, only 2 patients had mild paravalvular leak. There was no second valve implantation. Moreover, no 30-day mortality or complications was reported. Following the transcatheter aortic valve implantation procedure, the heart and valve functions had improved significantly. During the follow-up period of 3-34 months, one patient died of lung cancer 13 months after the operation.

Conclusion

This early experience has provided preliminary evidence for the safety and efficacy of transcatheter aortic valve implantation procedure with the balloon-expandable system in the developing world with an increasing aging population.     

Comparison of superior septal approach with left atriotomy in mitral valve surgery

Objective

In this study, we aimed to compare clinical outcomes of superior transseptal approach with the conventional left atriotomy in patients undergoing mitral valve surgery.

Methods

Between January 2010 and November 2012, a total of 91 consecutive adult patients (39 males, 52 females; mean age: 54.0±15.4 years; range, 16 to 82 years) who underwent mitral valve surgery in the Division of Cardiovascular Surgery at Koşuyolu Training Hospital were included. The patients were randomized to either superior transseptal approach (n=47) or conventional left atriotomy (n=44). Demographic characteristics of the patients, comorbidities, additional interventions, intraoperational data, pre- and postoperative electrophysiological study findings, and postoperative complications were recorded.

Results

Of all patients, 86.7% (n=79) were in New York Heart Association Class III, while 12 were in New York Heart Association Class IV. All patients underwent annuloplasty (42.9%) or valve replacement surgery (57.1%). There was no significant difference in pre- and postoperative electrocardiogram findings between the groups. Change from baseline in the cardiac rhythm was statistically significant in superior transseptal approach group alone (P<0.001). There was no statistically significant difference in mortality rate between the groups. Permanent pacemaker implantation was performed in 10.6% of the patients in superior transseptal approach group and 4.5% in the conventional left atriotomy group. No statistically significant difference in bleeding, total length of hospital and intensive care unit stay, the presence of low cardiac output syndrome was observed between the groups.

Conclusion

Our study results suggest that superior transseptal approach does not lead to serious or fatal adverse effects on sinus node function or atrial vulnerability, compared to conventional approach.     

Laser Doppler anemometry measurements of steady flow through two bi-leaflet prosthetic heart valves

Introduction

In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench.

Objective

To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models) exposed to a steady flow regime, on four distinct sections, three downstream and one upstream.

Methods

To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min. ) and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements.

Results

It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found.

Conclusions

Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM) is superior to the 21 AJ - 501 model (Master Series). Based on the results, future studies can choose to focus on specific regions of the these valves.     

Minimally Traumatic Techniques for In Utero Access and Fetal Surgery

Background and Objectives:

Prenatal interventions may prevent some sequelae of congenital anomalies, yet open fetal surgery is limited by preterm labor. We are developing amnioscopic strategies to reduce risks for in utero surgery.

Methods:

Seven fetal sheep were accessed percutaneously under ultrasound guidance, via maternal laparoscopy/transuterine trocars, or via laparoscopically assisted partial uterine exteriorization (mini-hysterotomy). Three fetal immobilization methods were investigated: 2 mm grasping forceps, 2-0 absorbable Roeder loop lasso, and detachable metal T-fasteners.

Results:

Percutaneous access with 2 mm trocars required accessible amniotic fluid pockets. The laparoscopically assisted method enabled 5 mm trocar placement under direct fetal visualization. Mini-hysterotomy avoided trocars and was leak-proof. 2 mm graspers enabled fetal manipulation with repeatable applications. Roeder loop sutures were not readily repositioned, and required two 3 mm or larger trocars. T-fasteners were easily deployed into fetal skin via the self-contained needle applicator with minimal hemorrhage. Cutaneous marks were present immediately from the grasper and T-fastener, but not at postoperative day 10. The Roeder loop produced no observable effects. All devices demonstrated adequate intrauterine performance.

Conclusions:

Minimally invasive fetal surgery promises to lower maternal-fetal risks. All strategies permitted prolonged amnioscopy and fetal manipulation. The 2 mm grasper was easiest to use, producing no observable lasting trauma.     

Effects of compression stockings on sympathetic activity and heart rate variability in individuals with spinal cord injury

Objective

To investigate whether wearing graduated compression stockings (GCS) could affect the sympatho-adrenergic and heart rate variability (HRV) responses at rest and after a strenuous wheelchair exercise in individuals with spinal cord injury (SCI).

Design

Crossover trial.

Setting

Department of Physical Medicine and Rehabilitation, Saint Etienne, France.

Participants

Nine men with SCI (five with low paraplegia: LP, four with high paraplegia: HP).

Interventions

Two maximal wheelchair exercise tests: with and without GCS (21 mmHg).

Main outcome measures

HRV measurements: high frequency (HF), low frequency (LF), and LF/HF ratio. Norepinephrine (NOR) and epinephrine (EPI), at rest and post-exercise. Secondary measures were: blood pressure, heart rate, maximal power output, oxygen uptake, stroke volume, cardiac output, at rest, during and after exercise.

Results

When wearing GCS: LFnu_wavelet-post significantly increased and HFnu_wavelet-post significantly decreased (P < 0.05) in SCI subjects, leading to an enhance ratio of LF_wavelet/HF_wavelet and a significantly increased in NOR_rest (P < 0.05).

Conclusions

GCS induces an enhanced sympathetic activity in individuals with paraplegia, regardless of the level of the injury. Enhanced post-exercise sympathetic activity with GCS may help prevent orthostatic hypotension or post-exercise hypotension.     

Comparison of the solution of histidine-tryptophan-alfacetoglutarate with histidine-tryptophan-glutamate as cardioplegic agents in isolated rat hearts: an immunohistochemical study

Introduction

Cardiac arrest during heart surgery is a common procedure and allows the surgeon to perform surgical procedures in an environment free of blood and movement. Using a model of isolated rat heart, the authors compare a new cardioplegic solution containing histidine-tryptophan-glutamate (group 2) with the histidine-tryptophan-alphacetoglutarate (group 1) routinely used by some cardiac surgeons.

Objective

To assess caspase, IL-8 and KI-67 in isolated rat hearts using immunohistochemistry.

Methods

20 Wistar male rats were anesthetized and heparinized. The chest was opened, cardioctomy was performed and 40 ml/kg of the appropriate cardioplegic solution was infused. The hearts were kept for 2 hours at 4ºC in the same solution, and thereafter, placed in the Langendorff apparatus for 30 minutes with Ringer-Locke solution. Immunohistochemistry analysis of caspase, IL-8, and KI-67 were performed.

Results

The concentration of caspase was lower in group 2 and Ki-67 was higher in group 2, both P<0.05. There was no statistical difference between the values of IL-8 between the groups.

Conclusion

Histidine-tryptophan-glutamate solution was better than histidine-tryptophan-alphacetoglutarate solution because it reduced caspase (apoptosis), increased KI-67 (cell proliferation), and showed no difference in IL-8 levels compared to group 1. This suggests that the histidine-tryptophan-glutamate solution was more efficient than the histidine-tryptophan-alphacetoglutarate for the preservation of hearts of rat cardiomyocytes.     

Humanitarian cardiac care in Arequipa, Peru: experiences of a multidisciplinary Canadian cardiovascular team

Background

The prevalence of cardiovascular disease and its associated mortality continue to increase in developing countries despite unparalleled improvements in cardiovascular medicine over the last century. Cardiovascular care in developing nations is often constrained by limited resources, poor access, lack of specialty training and inadequate financial support. Medical volunteerism by experienced health care teams can provide mentorship, medical expertise and health policy advice to local teams and improve cardiovascular patient outcomes.

Methods

We report our experience from annual successive humanitarian medical missions to Arequipa, Peru, and describe the challenges faced when performing cardiovascular interventions with limited resources.

Results

Over a 2-year period, we performed a total of 15 cardiac repairs in patients with rheumatic, congenital and ischemic heart disease. We assessed and managed 150 patients in an outpatient clinic, including 7 patients at 1-year postoperative follow-up.

Conclusion

Despite multiple challenges, we were able to help the local team deliver advanced cardiovascular care to many patients with few alternatives and achieve good early and 1-year outcomes. Interdisciplinary education at all levels of cardiac care, including preoperative assessment, intraoperative surgical and anesthetic details, and postoperative critical care management, were major goals for our medical missions.