Ventricular Defect Research Articles

Intensive management of acute right heart failure

Not a few patients in children and adolescents are suffering from right ventricular (RV) dysfunction resulting from various conditions such as chronic lung disease, left ventricular dysfunction, pulmonary hypertension, or congenital heart defect. The RV is different from the left ventricle in terms of ventricular morphology, myocardial contractile pattern and special vulnerability to the pressure overload. Right ventricular failure (RVF) can be evaluated in terms of decreased RV contractility, RV volume overload, and/or RV pressure overload. The management for RVF starts from clear understanding of the pathophysiology of RVF. In addition to correction of the underlying disease, management of RVF per se is very important. Meticulous control of volume status, inotropic agents, vasopressors, and pulmonary selective vasodilators are the main tools in the management of RVF. The relative importance of each tool depends on the individual clinical status. Medical assist device and surgery can be considered selectively in case of refractory RVF to optimal medical treatment.

Cardiac Regeneration

Cellular therapy to replace lost myocardial mass with new, contractile myocardium has the potential to revolutionize the treatment of myocardial infarction and heart failure. Studies have shown small but consistent improvements in mechanical function, largely independent of the cell type chosen. The reasons for this lack of specificity are presently unknown. In the current issue of Circulation, Wall et al 1 present computational models that suggest that the injection of passive materials alone may improve ejection fraction and reduce wall stress in the ventricle. The present study raises the possibility that some cellular therapies contribute to increased heart function purely through a passive mechanism rather than through active contraction associated with the addition of new myocytes. Because materials lack many of the uncertainties associated with cellular therapies (eg, mode of delivery, homing, immune rejection, arrhythmias), and because they can be engineered to have a number of inherent advantages (eg, uniformity, reliability, greater safety, reduced cost), one conclusion of the current finding is that biomaterials alone may be important for future cardiac therapy. Article p 2627 Given the results of this study by Wall and colleagues,1 it is also clear that passive contribution must be separated from active contribution to evaluate the efficacy of any cell therapy approach. Passive contribution can result from replacing a stiff material, such as an infarct, with a more compliant material. Completely replacing the infarcted tissue with a compliant scaffold can accomplish this task. Matsubayashi and colleagues 2 demonstrated that passive properties can improve global heart function by seeding a synthetic scaffold with smooth-muscle cells before implantation in a fullthickness ventricular defect model. The smooth-muscle cells, which are unlikely to contribute contractile function, increased elastic tissue formation and likely increased the compliance of the scaffold. Skeletal myoblasts, which have been employed in clinical trials, are also unlikely to contract in synchrony with the normal myocardium. These cells do not make connexins, the building blocks of gap junctions, and are therefore unlikely to make electrical connections with the native myocardium.3 Several reports, however, have documented improved mechanical function with these cells. 4 Such improvement is likely the result of improved passive function and not the addition of contractile mass. The present study suggests that this improvement could also result from the addition of an inert biomaterial to the infarcted region. Whereas skeletal myoblasts leave the heart susceptible to arrhythmias, 5 a biomaterial can be chosen to provide electri

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Sinus of Valsalva Aneurysm (SVA)

Echocardiography is widely used in the evaluation of patients with chest pain and can provide important information regarding left ventricular function, valvular competency, and structural defects. The authors report a patient in whom transesophageal echocardiography confirmed the presence of a sinus of Valsalva aneurysm (SVA), an uncommon congenital defect of the proximal aorta that may be associated with high morbidity and mortality. Aneurysm of the sinus of Valsalva results from the separation of the aortic media from the aortic annulus. It is often the result of a congenital cardiac defect but can also be acquired in patients with Marfan's syndrome, after cardiac surgery or trauma, and as a result of infection. This is a rare case of an SVA causing coronary artery compression, resulting in chest pain, coronary ischemia, and ventricular tachycardia.

Ruptura subaguda da parede livre do ventrículo esquerdo pós-infarto agudo do miocárdio: relato de caso e revisão de literatura

Post-infarction left ventricular free wall rupture is life threatening and not uncommon. Surgical experience is largely anecdotal with different techniques being used since the first successful surgical treatment was described. Here we present two patients with subacute left ventricular rupture that were managed using different perioperative strategies. Although the aim of surgical intervention is first and foremost to remove the threat to life by relieving of tamponade and closure of the ventricular defect, longer-term goals were those of conventional coronary operations, i.e., to prevent or limit

Treadmill Exercise Produces Larger Perfusion Defects Than Dipyridamole Stress N-13 Ammonia Positron Emission Tomography

The aim of this study was to compare treadmill exercise (TEX) and dipyridamole stress on the uptake and retention of N-13 ammonia. Size and severity of stress-induced myocardial perfusion defects are clinically important. Because ammonia uptake and retention seems to be related to perfusion, viability, and metabolism, exercise stress might induce larger perfusion defects than dipyridamole stress. Twenty-six patients underwent TEX and dipyridamole stress N-13 ammonia positron emission tomography (PET). Images were assessed with a 17-segment model and a five-point score. Summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) were calculated. Left ventricular (LV) defect sizes were measured quantitatively with a 70% threshold for abnormal perfusion. Compared with dipyridamole stress, TEX yielded larger SSS (9.1 +/- 5.7 vs. 6.9 +/- 5.9; p < 0.01), SDS (5.8 +/- 4.7 vs. 3.7 +/- 4.6; p < 0.02), and percentage of LV stress defect (19.3 +/- 11.5% vs. 13.8 +/- 13.6%; p < 0.02). In patients achieving adequate exercise, TEX N-13 ammonia PET myocardial perfusion imaging (MPI) yields larger stress perfusion defects than dipyridamole stress and might reflect the true myocardial ischemic burden. Treadmill exercise might be the preferred method of stress for routine N-13 ammonia PET MPI.

Repair of Right Ventricular Free Wall Defect With a De-Epithelized Pedicled Myocutaneous Latissimus Dorsi Muscle Flap

Rupture of the right ventricle may occur because of sternal dehiscence or mediastinitis after cardiac surgery. Direct suture, polytetrafluoroethylene patch, fasciae, and muscle flaps have been used to close a right ventricular rupture. A unique occurrence of repair of a full-thickness right ventricle defect with a de-epithelized myocutaneous flap is presented. Our patient experienced a rupture of the right ventricle complicating sternal wound infection. The rupture was reconstructed with a polytetrafluoroethylene patch, but the patch needed to be removed because of infection. The defect was reconstructed with a de-epithelized myocutaneous latissimus dorsi flap. The patient indicated no signs of complication during follow-up.

Cardiac Transplantation for Giant Sarcoma of the Left Ventricle

An 8-year-old boy with a growing left ventricular mass underwent cardiac surgery for tumor resection. Radical resection seemed impossible, and thus, only a large biopsy sample was taken with a concomitant patch closure of the left ventricular defect. Histological examination revealed a rare liposarcoma. The patient was discharged without further therapy. Five months later, the patient was transferred to our hospital because his clinical condition had worsened to New York Heart Association class IV, and a recurrent left ventricular tumor became evident. MRI (Figures 1, …

Using heart sounds to improve automated electrocardiographic differentiation between ventricular pacing and conduction defects

Using heart sounds to improve automated electrocardiographic differentiation between ventricular pacing and conduction defects

Loss of Apaf-1 leads to partial rescue of the HAND2-null phenotype

HAND2 is an essential transcription factor for cardiac, pharyngeal arch, and limb development. Apoptosis in the HAND2-null embryo causes hypoplasia of the right ventricle and pharyngeal arches leading to lethality by embryonic day (E)10.0 from heart failure. In order to investigate the role of apoptosis in inducing the HAND2-null phenotype, we generated mouse embryos lacking both HAND2 and Apaf-1, a central downstream mediator of mitochondrial damage-induced apoptosis. In contrast to HAND2 −/− embryos, HAND2 −/− Apaf-1 −/− embryos at E10.5–11.0 had well-developed pharyngeal arches, aortic arch arteries, and no signs of cardiac failure. TUNEL analysis through pharyngeal arches of HAND2 −/− Apaf-1 −/− embryos revealed decreased apoptosis and the embryos had clearly patent aortic arch arteries. However, ventricular hypoplasia and cell death were unchanged in these animals compared to HAND2 −/− embryos, resulting in growth arrest at E11.0. Our study suggests that loss of HAND2 in the pharyngeal arch mesenchyme leads to apoptosis in an Apaf-1-dependent fashion and that, while loss of aortic arch integrity contributes to the early lethality, the ventricular defects are independent of arch development.

Surgical management of tunnel-like subaortic stenosis via ventricular septal defect in a patient with the interrupted aortic arch

A 24-day-old male with interrupted aortic arch (type B), ventricular septal defect, and tunnel-like subaortic stenosis underwent a one-stage surgical treatment. The operative procedure comprised reconstruction of the aortic arch, transatrial excision of the subaortic fibromuscular tissue via the ventricular sepatal defect, and patch closure of the defect. The patient tolerated the procedure well and the postoperative echocardiography demonstrated a residual pressure gradient across the left ventricular outflow tract of 20 mmHg. Our result suggests that the transatrial surgical management of subaortic stenosis via the ventricular sepatal defect produces a safe and promising surgical option.

Elucidating the Genetic Cause of Congenital Heart Defects

After completing this article, readers should be able to: 1. Understand the relationship between haploinsufficiency and autosomal dominant transmission. 2. Describe how incomplete penetrance and variable expressivity relate to the genetic analysis of congenital heart disease. 3. Delineate the current hypothesis for the cause of DiGeorge syndrome/velocardiofacial syndrome. 4. Understand the relationship between heterotaxy and congenital heart defects. 5. Discuss the possible role of folic acid in the development of congenital malformations. Congenital heart defects (CHD) are among the most common birth defects, with an incidence of 4 to 50 per 1,000 live births. CHD are the leading noninfectious cause of death in the first postnatal year. Although CHD long have been recognized as a component of complex genetic syndromes, a genetic cause for isolated CHD has been less obvious; the source of these defects generally has been believed to be multifactorial. In the past decade, however, molecular genetic studies have revealed that in many instances, CHD exhibits classic mendelian transmission and can be traced to discrete gene defects. The mendelian transmission of CHD may have been obscured by a variety of factors. As the genetic causes of CHD are being elucidated, substantial genetic heterogeneity (ie, mutations in different genes giving rise to the same phenotype) is becoming apparent. Another confounding factor in the genetic analysis of CHD has been the reduced penetrance of the mutant phenotypes, in which some individuals carrying the disease-causing mutations appear to be free of CHD. A third confounding factor has been variable expressivity. Clinically, CHD are classified anatomically (eg, conotruncal defects, atrial or ventricular septation defects). This classification has led to the bias that a particular genetic defect would result in a predictable anatomic defect. Although the resultant anatomic defects reflect the function of the mutated gene during cardiac development with many mutations, some genes impinge on several developmental …

Change of serum growth factors in infants with isolated ventricular defect undergoing surgical repair

Background. Despite increasing clinical use and recent evidence that insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), and human growth hormone (hGH) target the heart, the clinical manifestations following the change in the serum growth factors in infants with isolated ventricular septal defect (VSD) undergoing surgical repair have not been clearly defined. Methods. Twenty normal infants (group I) and 44 consecutive infants with echocardiography established isolated VSD (aged from 3 months to 1 year; body weight from 6.0 ± 1.8 kg to 8.2 ± 1.6 kg) were investigated. Among 44 infants with VSD, 20 with shunt fraction, Qp/Qs ≤1.5 were free of symptoms of congestive heart failure (group II); 24 with shunt fraction, Qp/Qs ≥2.0 were in congestive heart failure (group IIIa); and 20 of these 24 infants had undergone VSD repair 6 months before their second study (group IIIb). Serum IGF-1, IGFBP-3, and hGH factors were determined by enzyme-linked immunosorbent assay using a monoclonal antibody. Results. The serum levels of IGF-1, IGFBP-3, and hGH factors were 111.9 ± 2.3 ng/mL, 22.0 ± 2.3 ng/mL, and 3.6 ± 0.7 μIU/mL for group I; 63.8 ± 8.2 ng/mL, 17.1 ± 1.6 ng/mL, and 4.1 ± 1.2 μIU/mL for group II; 24.0 ± 2.6 ng/mL, 9.4 ± 0.7 ng/mL, and 14.7 ± 3.5 μIU/mL for group IIIa; 79.4 ± 12 ng/mL, 20.3 ± 1.3 ng/mL, and 4.3 ± 0.7 μIU/mL for group IIIb. In comparison to group I, the decrease in serum levels of IGF-1 and IGFBP-3 in groups II and IIIa were statistically significant (in group II 43% and 32%, p < 0.05; in group IIIa 79% and 37%, p < 0.01). Also the increase in serum level of hGH concentration in group IIIa was significant (increased threefold, p < 0.01). Interestingly, the change in serum levels of IGF-1, IGFBP-3 (decrease), and hGH (increase), returned to the normal range of serum levels after VSD repair in group IIIb. All congestive heart failure symptoms subsided in group IIIb during follow-up. Conclusions. Improvement in serum levels of IGF-1, IGFBP-3, and hGH were identified in infants with VSD after surgical repair.

Cardiomyoplasty: ventricular reconstruction after tumor resection.

Although cardiac transplantation has been performed for complete removal of ventricular tumors, complete surgical resection with ventricular reconstruction is desirable. Thus patients with benign tumors would probably be cured, and those with malignant tumors would have a better prognosis. In this study extensive and complete surgical resection of ventricular tumors is followed by anatomic and functional ventricular reconstruction with a dynamic cardiomyoplasty procedure. Seven patients (mean age, 32.7 years) underwent complete resection of ventricular tumors. Histologic types were distributed as follows: fibroma in 2 patients and sarcoma, lymphosarcoma, hemangioma, lipoma, and metastatic angiosarcoma, respectively, in the remaining 5 patients. Six of the patients were considered candidates for heart transplantation because of the extent of tumor invasion. Surgery consisted of 4 steps: (1) tumor resection; (2) coronary artery resection (when invaded by the tumor) and coronary artery bypass grafting; (3) valvular reconstruction (when possible) or replacement; and (4) ventricular wall reconstruction with a pericardial patch for closure of the ventricular defect (neoendocardium) covered by the electrostimulated latissimus dorsi muscle flap (neomyocardium). All patients survived surgical intervention, but 2 late postoperative deaths are reported. Among the surviving patients, early complications played a major role in their postoperative course and consisted of arrhythmias, atrioventricular block necessitating a dual-chamber pulse generator, respiratory insufficiency, and heart failure. Two patients were assisted postoperatively with an intra-aortic balloon pump. On postoperative follow-up (mean, 72.4 +/- 8.5 months), an improvement in the patients' functional status was observed. Patients moved from a mean New York Heart Association functional class of 2.8 to a mean functional class of 1.2. The excellent long-term evolution without recurrence, ventricular dysfunction, and/or thromboembolic complications implies that cardiomyoplasty could be recommended as an alternative to heart transplantation for the therapy of large ventricular tumors.

Fetale Echokardiographie - See with new eyes

Cardiac malformations occur in 8 to 10 per 1000 live births and are thus the most common congenital anomalies. Fetal echocardiography is gaining importance in the evaluation of fetuses with suspected cardiac malformations. Obstetricians, pediatric cardiologists and pediatric surgeons require training in the new technology. We present an interactive CD-ROM designed to facilitate training in fetal echocardiography. Ultrasound technology generates two-dimensional images. Three-dimensional evaluation requires interpreting the movements of the probe by the examiner and the excursions of the fetal heart. The CD-ROM Fetal Echocardiography - See With New Eyes uses computer-generated graphics to portray the most common cardiac malformation (ventricular, atrial and atrioventricular septal defects; pulmonary stenosis; tricuspid atresia; hypoplastic left heart syndrome; tetralogy of Fallot; transposition of the great arteries 1. Schematic three-dimensional models and digital video sequences are shown. We aimed at linking virtual 3-dimensional models with realistic ultrasound sequences. Written interactive information and references are provided. The CD-ROM runs on conventional PC and CD drives.

Dilated cardiomyopathy

The management of patients with dilated cardiomyopathy (DCM) heart failure starts with the determination of the underlying diagnosis, definition of the hemodynamic character (eg, systolic, diastolic, valvular, right- and left-sided heart dysfunction), recognition of complicating factors (eg, atrial fibrillation, renal dysfunction), and consideration for any surgically remedial lesions (eg, severe valvular regurgitation, high-grade coronary artery occlusive disease). Angiotensin-converting enzyme inhibitors, beta-blocking agents, digoxin, and judicious diuretic administration make up the therapeutic plan for patients with symptomatic DCM heart failure. Angiotensin-converting enzymes are indicated for patients with DCM who have mild or no detectable symptoms; whether this subgroup would benefit from long-term beta-blockade remains to be established. Spirolactone also has been shown to be effective in patients with more advanced stages of heart failure. Biventricular pacing (cardiac resynchronization therapy) recently has been approved for use in patients with DCM and a left ventricular or intraventricular conduction defect and a QRS duration of longer than 140 msec. More intense pharmacotherapy, mechanical devices, and transplantation are directed at patients with severely symptomatic end-stage DCM. The effectiveness of any heart failure treatment plan is very much dependent on nonpharmacologic approaches, including dietary measures, exercise conditioning, and similar considerations, all of which are best delivered by dedicated heart failure programs.

Ventricular septal defect and aortic regurgitation

Perimembranous ventricular septal defects, account for 70–80% of ventricular septal defects in western countries and aortic regurgitation is an uncommon complication, occurring in 2–5% of cases. This complication however, occurs very commonly in patients with subpulmonary ventricular septal defects, particularly those that are greater than 5 mm in diameter. Furthermore, in far eastern countries, subpulmonary defects are more prevalent accounting for 21–30% of defects as compared to 5–8% in western countries. The genesis of aortic regurgitation is related principally to the deficiency of aortic valve cusp support in the subpulmonary defect, whereas a defective commissure between the non- coronary and the right cusp and occasionally deformity of the aortic cusps themselves are most often described with permimembranous defects. Because of the progressive nature of aortic regurgitation in patients with subpulmonary defects, it is recommended that early ventricular septal defect closure should be carried out in patients with these defects when the aortic valve is distorted or prolapsed or when the first sign of aortic regurgitation occurs. The natural history of aortic regurgitation in patients with perimembranous ventricular defects is less well defined, but the recommendation is made at many centers that patients with a distorted or prolapsed aortic cusp or aortic regurgitation also should have the VSD closed at an early date. For patients with so-called ‘silent’ aortic regurgitation (only Doppler proven aortic regurgitation) the decision is more difficult. In subpulmonary defects we favor early closure with this sign. In patients with perimembranous defects it is probably equally prudent to follow such patients carefully and to close the defect if the aortic regurgitation appears to increase by Doppler or becomes audible.

Biventricular repair of transposition of the great arteries and unbalanced ventricles

Background: It is well established that the arterial switch operation is the surgical procedure of choice in patients with transposition of the great arteries and balanced ventricular anatomy. The surgical approach of choice in patients with transposition but unbalanced ventricular size is unknown. Objectives: Since the beginning of the arterial switch operation program, patients with transposition of the great arteries and unbalanced ventricles underwent biventricular repair by means of the arterial switch operation and repair of any associated lesions, either through a single or staged surgical procedure. The aim of this retrospective study is to analyze whether this approach can be proposed to such patients. Methods: Forty-four patients with transposition of the great arteries and unbalanced ventricles underwent this surgical approach since 1984. Two groups were defined: group I had transposition with a dominant right ventricle (n = 28), and group II had transposition with a dominant left ventricle (n = 16). In group I the median age and weight at the arterial switch operation were 8.5 days (range, 5-70 days) and 3.1 kg (range, 1.5-3.7 kg), respectively. The median end-diastolic left ventricular volume, mass, and long-axis ratio were 15 mL/m2 (range, 11-16 mL/m2), 31.5 g/m2 (range, 20-66 g/m2), and 0.85 (range, 0.9-0.7), respectively. The mitral valve diameter was slightly hypoplastic, with a median z value of –1.22 (range, –0.3 to 3.7). In group 2 the median age and weight at the arterial switch operation were 42 days (range, 8 days–15 years) and 3.5 kg (range, 2.8-35 kg), respectively. Associated lesions in this group were coarctation in 9 and single (n = 12) or multiple (n = 4) ventricular septal defects. The median long-axis ratio and tricuspid z value were 0.6 (range, 0.3-0.8) and –0.9 (range, –0.5 to 3.3), respectively. In this group 9 patients had a single-stage procedure with fenestrated ventricular defect patches, atrial septal defect patches, or both; 7 patients underwent the staged approach. Results: In group I there was 1 early death from sepsis after weaning from postoperative extracorporeal membrane oxygenation. Three patients had severe pulmonary hypertension, one of whom died 1 year later. All survivors demonstrated, at discharge from the hospital, equilibrated ventricular size, with a median left ventricular end-diastolic volume of 25 mL/m2 (range, 21-30 mL/m2). In group II there were 2 early and 1 late deaths. All early deaths occurred in patients without voluntary residual intracardiac shunts. Median early postoperative long-axis ratio and tricuspid z value were 0.8 (range, 0.7-1) and –0.2 (range, 0.74 to 1.2), respectively. Conclusion: This study demonstrates that the arterial switch operation in patients with transposition of the great arteries and unbalanced ventricles remains a good surgical option.

An anti-CD11/CD18 monoclonal antibody in patients with acute myocardial infarction having percutaneous transluminal coronary angioplasty (the FESTIVAL study)

Maximal benefits of coronary reperfusion after acute myocardial infarction (AMI) with ST-segment elevation may be attenuated by neutrophil-mediated reperfusion injury. Inflammatory mediators released from potentially viable myocytes cause activation of neutrophils, which traverse the endothelium and enter the myocardium. This process involves interaction between the neutrophil-expressed CD11/CD18 and endothelial-expressed intercellular adhesion molecule-1 (ICAM-1). Preclinical studies have shown that monoclonal antibodies (MAb) to CD18 can limit infarct size and preserve left ventricular function. We sought to determine the initial clinical safety and tolerability of Hu23F2G (LeukArrest), a humanized MAb to CD11/CD18, in patients with AMI who underwent percutaneous transluminal coronary angioplasty (PTCA). Sixty patients with AMI were randomized to low- (0.3 mg/kg) or high-dose (1.0 mg/kg) Hu23F2G or to placebo immediately before PTCA. We found no clinically significant differences in vital signs, physical examination, laboratory evaluation, or need for subsequent cardiac interventions. In Hu23F2G treatment groups, serum concentration of Hu23F2G increased rapidly to 3,234 ± 1,298 μg/L (low-dose group) and 15,558 ± 4409 μg/L (high-dose group) between 5 and 60 minutes, then declined over 72 hours to near-baseline values. Myocardial single-photon emission computed tomographic imaging 120 to 260 hours after PTCA showed no statistically significant differences in final left ventricular defect size. Hu23F2G was well tolerated, with no increase in adverse events, including infections. Thus, Hu23F2G appears safe and well tolerated in patients undergoing PTCA for AMI.

Teratogenic effect of bis‐diamine on embryonic rat heart

ABSTRACT Bis‐diamine induces conotruncal anomalies including persistent truncus arteriosus, tetralogy of Fallot, interruption of the aortic arch, and ventricular septal defect in rat embryos when administered to the mother. Bis‐diamine also induces extracardiac malformations including thymic hypoplasia, facial dysmorphism, forelimb anomalies and diaphragmatic hernia. However, the teratogenic mechanisms of this chemical in early developing rat hearts have not been fully established. Chimeric studies in chick and quail embryos demonstrated that the cranial neural crest cells reached the cardiac outflow tract, contributing to aorticopulmonary and truncal septation. Since an ablation of the cranial neural crest also produced the conotruncal anomalies, bis‐diamine is proposed to disturb the normal migration of cardiac neural crest cells to the heart. Based on our data concerning cardiac anomalies induced by bis‐diamine, we reviewed how the cardiac malformations were morphologically established in early developing rat hearts. Our data showed that 1) cardiovascular anomalies induced by bis‐diamine are time‐ and species or strain‐ dependent. 2) bis‐diamine reduces the number of neural crest cells migrating to participate in the conotruncal septation, 3) bis‐diamine induces anomalous coronary arteries, thin ventricular walls and epicardial defects, and 4) some embryos cultured in the medium containing bis‐diamine had extra‐cardiac abnormalities including abnormal location of the otic placodes and delay in mid brain closure. Conclusively, bis‐diamine does not appear to merely affect the cardiac development, but rather disturbs normal development of all the organs contributed to by neural crest cells.