Is mitral valve prolapse due to cardiac entrapment in the chest Cavity? A CT view

Increased incidence of mitral valve prolapse in children with pectus chest wall deformity

BACKGROUND

Pectus anomalies constitute 95% of chest anomalies. Pectus carinatum (PC) and excavatum (PE) are often asymptomatic in childhood. However, symptoms and signs such as chest pain, dyspnea, and mitral valve prolapse (MVP) can be seen in pectus anomalies. Demographic characteristics and accompanying cardiac signs in children with pectus deformity were investigated.

METHODS

In this study, the clinical findings for children with pectus deformity, and the incidence of MVP and other concomitant heart diseases detected in echocardiographic examinations were evaluated.

RESULTS

Eighty-two children with PE, 27 with PC, and 107 healthy children were included in this study. In the echocardiographic examination of PE, PC patients, and healthy children, MVP was detected with frequencies of 25%, 33%, and 2% respectively.

CONCLUSIONS

The study showed that pectus anomalies were associated with an increased incidence of MVP. All patients with pectus deformity should therefore undergo a screening echocardiogram in adolescence to assess for the presence of MVP.

Straight Back Syndrome Presented with Chest and Back Pain: A Case Report

A 17-year-old female adolescent presented with her mother to our clinic with a two-month history of left-sided chest pain and a one-week history of middle back pain. We diagnosed straight back syndrome based on the chest and thoracic radiographic findings and symptoms of chest pain, palpitations, and dyspnea. We reassured the patient that the disease was benign and advised her to start and continue chiropractic therapy. All symptoms, including back pain, disappeared in three weeks. Straight back syndrome is under-diagnosed, and back pain is less recognized as a symptom of the disease.

Preoperative resource utilization prior to minimally invasive repair of pectus excavatum

BACKGROUND

Preoperative testing to assess the physiologic impact of pectus excavatum is sometimes ordered to meet third-party payor preauthorization requirements. This study describes the utility of physiologic testing prior to minimally invasive repair of pectus excavatum (MIRPE).

METHODS

We retrospectively reviewed patients that underwent MIRPE from 1/2012-7/2016 at two academic children's hospitals. Data collected included demographics, insurance, Haller Index (HI), pulmonary function tests (PFTs) and echocardiograms (ECHO) obtained, and preauthorization denials.

RESULTS

A total of 360 patients (mean age 15.7 ± 2.0 years; mean HI 4.5 ± 1.5) underwent MIRPE (Hospital 1: 189, Hospital 2: 171). Commercial insurers covered 84% of patients. Hospital 1 obtained more frequent preoperative testing (PFTs: 73% vs 6%, p < 0.0001). Overall, 72% of PFTs were normal with abnormal studies limited to mild findings. Similarly, 85% of ECHOs were normal. Third-party payors more frequently denied preauthorization for MIRPE at Hospital 2 (11% vs. 5%, p = 0.03).

CONCLUSIONS

More frequent preoperative testing may decrease initial preauthorization denials for MIRPE; however, this increased utilization of resources may not be necessary as the majority of test results are normal.

Echocardiography Reveals Heart Abnormalities in Pediatric Pectus Carinatum

BACKGROUND

Symptoms including chest pain and palpitations are commonly described by pediatric patients with pectus deformity. Cardiac anomalies are thought to be less common in patients with pectus carinatum (PC) than those in patients with pectus excavatum; however, no literature supports this presumption. Echocardiogram (echo) assesses heart structure and function. We hypothesized that a screening echo would 1) determine the relationship between symptoms and echo findings and 2) define the incidence of cardiac defects in patients with PC.

MATERIALS AND METHODS

This is an institutional review board-approved retrospective review of all patients with PC who received an echo from 2015 to 2019 at a tertiary care children's hospital. Echo findings and patient-reported symptoms were collected from electronic health records. Descriptive statistics were used to assess correlation between findings.

RESULTS

We identified 155 patients with PC who received an echo with complete data available for analysis. Of these, 44 (28.4%) reported chest pain and 13 (8.4%) reported palpitations. Echo results showed that five patients (3.2%) had mitral valve prolapse and 11 (7.1%) had aortic root dilation. Patient-reported symptoms were not significantly associated with abnormal echo findings.

CONCLUSIONS

Chest pain and palpitations frequently occur in the PC population but may not be related to abnormal echo findings. We recommend screening echo in patients with PC regardless of symptoms.

Genome-wide association study of degenerative mitral valve disease in Maltese dogs

Genome-wide association study (GWAS) is a powerful tool for identifying the genetic causes of various diseases. This study was conducted to identify genomic variation in Maltese dog genomes associated with degenerative mitral valve disease (DMVD) development and to evaluate the association of each biological condition with DMVD in Maltese dogs. DNA was extracted from blood samples obtained from 48 Maltese dogs (32 with DMVD and 16 controls). Genome-wide single nucleotide polymorphism (SNP) genotyping was performed. The top 30 SNPs from each association of various conditions and genetic variations were mapped to their gene locations. A total of 173,662 loci were successfully genotyped, with an overall genotype completion rate of 99.41%. Quality control analysis excluded 46,610 of these SNPs. Manhattan plots were produced using allelic tests with various candidate clinical conditions. A significant peak of association was observed between mitral valve prolapse (MVP) and SNPs on chromosome 17. The present study revealed significant SNPs in several genes associated with cardiac function, including PDZ2, Armadillo repeat protein detected in velo-cardio-facial syndrome, catenin (cadherin-associated protein) alpha 3, low-density lipoprotein receptor class A domain containing protein 4, and sterile alpha motif domain containing protein 3. To our knowledge, this is the first study of a genetic predisposition to DMVD in Maltese dogs. Although only a limited number of cases were analyzed, these data could be the basis for further research on the genetic predisposition to MVP and DMVD in Maltese dogs.

Connective Tissue and Age-Related Diseases

We begin this chapter by describing normal characteristics of several pertinent connective tissue components, and some of the basic changes they undergo with ageing. These alterations are not necessarily tied to any specific disease or disorders, but rather an essential part of the normal ageing process. The general features of age-induced changes, such as skin wrinkles, in selected organs with high content of connective or soft tissues are discussed in the next part of the chapter. This is followed by a section dealing with age-related changes in specific diseases that fall into at least two categories. The first category encompasses common diseases with high prevalence among mostly ageing populations where both genetic and environmental factors play roles. They include but may not be limited to atherosclerosis and coronary heart disease, type II diabetes, osteopenia and osteoporosis, osteoarthritis, tendon dysfunction and injury, age-related disorders of spine and joints. Disorders where genetics plays the primary role in pathogenesis and progression include certain types of progeria, such as Werner syndrome and Hutchinson-Gilford progeria belong to the second category discussed in this chapter. These disorders are characterized by accelerated signs and symptoms of ageing. Other hereditary diseases or syndromes that arise from mutations of genes encoding for components of connective tissue and are less common than diseases included in the first group will be discussed briefly as well, though they may not be directly associated with ageing, but their connective tissue undergoes some changes compatible with ageing. Marfan and Ehlers-Danlos syndromes are primary examples of such disorders. We will probe the role of specific components of connective tissue and extracellular matrix if not in each of the diseases, then at least in the main representatives of these disorders.

Relief of exertional dyspnea and spinal pains by increasing the thoracic kyphosis in straight back syndrome (thoracic hypo-kyphosis) using CBP® methods: a case report with long-term follow-up

[Purpose] To present the clinically significant improvement of straight back syndrome (SBS) in a patient with spinal pain and exertional dyspnea. [Subject and Methods] A 19 year old presented with excessive thoracic hypokyphosis and other postural deviations. A multimodal CBP^® mirror image^® protocol of corrective exercises, traction procedures and spine/posture adjusting were given over an initial 12-week course of intensive treatment followed by a 2.75 year follow-up with minimal supportive treatment. [Results] The patient had significant postural improvements in all postural measures and specifically a 14° increase in the thoracic kyphosis that was maintained at long-term follow-up. The postural improvements were consistent with relief of exertional dyspnea and pain, as well as increases in both antero-posterior thoracic diameter and the ratio of antero-posterior to transthoracic diameter, measurements critical to the wellbeing of patients with SBS. [Conclusion] Long-term follow-up confirmed stable improvement in physiologic thoracic kyphosis in this patient. Nonsurgical correction in thoracic hypokyphosis/SBS can be achieved by mirror image traction procedures configured to flex the thoracic spine into hyperkyphosis as well as corrective exercise and manipulation as a part of CBP technique protocols.

Nonsurgical correction of straight back syndrome (thoracic hypokyphosis), increased lung capacity and resolution of exertional dyspnea by thoracic hyperkyphosis mirror image® traction: a CBP® case report

[Purpose] To present the increase in thoracic kyphosis in a patient suffering from exertional dyspnea, reduced lung capacity, and spinal pains related to straight back syndrome (SBS). [Subject and Methods] A 33-year-old male patient was put on a CBP^® corrective care program involving mirror image^® traction procedures designed to increase the thoracic kyphosis. [Results] This patient had a 10° improvement in thoracic kyphosis in 16-weeks that was maintained 7-months later. There was a simultaneous reduction of pain, resolved exertional dyspnea, and a greater than 2 liter increase in lung capacity. [Conclusion] This case illustrates that nonsurgical improvement in thoracic kyphosis in a patient with SBS is possible and that this may positively influence lung capacity, health and function.

Mechanical microenvironment regulation of age-related diseases involving degeneration of human skeletal and cardiovascular systems

Age-related diseases involving degeneration of human skeletal and cardiovascular systems are now critical problems worldwide. The current review focuses on a common pathophysiological association between primary osteoporosis and vascular calcification, and reviews the mechanical response of bone cells and vascular cells to mechanical stress, as well as the coordination mechanism for intercellular signaling. With aging, calcium is lost from bones but deposited in the cardiovascular system. Bone metabolism-related molecules, such as alkaline phosphatase, matrix Gla protein, osteocalcin, osteopontin, and collagen type I; inflammatory cytokines, such as interleukin-1, -6, and tumor necrosis factor; and lipid metabolism related molecules, such as oxidized low density lipoprotein; mediate signaling in primary osteoporosis and vascular calcification. The mechanical microenvironment is a common pathophysiological basis for primary osteoporosis and vascular calcification. Mobilization of calcium from bone to vessel determines the regression rate, which could be controlled using a mechanical microenvironment. We highlight several issues: (1) linked features between primary osteoporosis and vascular calcification, and detailed changes of the mechanical microenvironment in degenerative bone or blood vessels, (2) signaling coordination mechanism between bone and vascular wall cells, and (3) calcium translocation mechanism. The degree to which these issues can be solved will help develop prevention and treatment strategies for age-related regression.

Advances in the understanding of the pathogenesis, progression and diagnosis of myxomatous mitral valve disease in dogs

A number of key questions remain unanswered in the pathogenesis of myxomatous mitral valve disease (MMVD). As MMVD typically afflicts small-breed dogs, a genetic basis has been implied. In addition, the fact that not all dogs within a risk group develop MMVDis still unexplained. Research into the pathogenesis of MMVD typically falls under three categorical divisions, namely genetic factors, mechanical factors of the valve and systemic factors. Genetic studies have implicated certain loci in the pathogenesis of MMVD. Of particular interest is the insulin-like growth factor (IGF)-1 locus, as IGF-1 is also associated with growth. The mechanical structure and function of the mitral valve have also received much attention in recent years. What has emerged is the notion of a highly complex dynamic structure, which has an uneven distribution of stress and strain according to the flow of blood. Research efforts have also identified a number of systemic factors such as cytokines and signalling pathways that may contribute to the failure of the valve. Serotonin remains an area of interest in this field. Taken together, the amalgamation of research efforts in these three areas will go a long way towards resolving the understanding of this disease.Another area of focus in MMVD has been the development of clinical tests to diagnose the onset of congestive heart failure. To this end, echocardiographic indices and biochemical markers have been investigated. Echocardiographic indices such as left atrial to aortic ratio and the N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) have been identified as specific risk factors to predict progression. Advanced imaging studies such as cardiac magnetic resonance imaging have enabled investigators to determine the earliest remodelling changes that occur in MMVD.

Myxomatous mitral valve disease in dogs: does size matter?

Myxomatous mitral valve disease (MMVD) is the most commonly diagnosed cardiovascular disease in the dog accounting for more than 70% of all cardiovascular disease in dogs. As are most canine diseases with genetic underpinnings, risk of MMVD is greatly increased in a subset of breeds. What is uncommon is that the vast majority of the breeds at elevated risk for MMVD are small or toy breeds with average adult weights under 9 kg. These breeds appear to have little in common other than their diminutive size. In the following review we propose a number of mechanisms by which relatively unrelated small breeds may have developed a predisposition for chronic valvular disorders. Although factors such as age are key in the expression of MMVD, taking a comprehensive look at the commonalities, as well as the differences, between the susceptible breeds may assist in finding the causal variants responsible for MMVD and translating them to improved treatments for both dogs and humans.

Right ventricular compression observed in echocardiography from pectus excavatum deformity

Pectus excavatum exists as varying anatomic deformities and compression of the right heart by the chest wall can lead to patient symptoms including dyspnea and chest pain with exertion. Echocardiography can be difficult but is critical to the evaluation and diagnosis of this patient population. Modifying standard views such as biplane transthoracic and 3-D transesophageal views may be necessary in some patients due to limitations from the abnormal anatomy of the deformed anterior chest wall. Apical four-chamber views when seen clearly can usually visualize any extrinsic compression to the right ventricle of the heart.

Indications and technique of Nuss procedure for pectus excavatum

Pectus excavatum most frequently involves the lower sternum and chest wall. Because the morphology varies, preoperative imaging for anatomic assessment and documentation of dimensions of the chest are important. Many modifications have been made to the minimally invasive procedure since it was first performed in 1987. As a result, there has been an increase in the number of patients seeking surgical correction. This article discusses the clinical features of pectus excavatum and reviews the preoperative considerations and the steps involved in the repair of the deformity.

Airway deformation in patients demonstrating pectus excavatum with an improvement after the Nuss procedure

PURPOSE

This study analyzed the inside appearance of the trachea and the main bronchus at the time of performing the Nuss procedure to test the hypothesis that the trachea and the main bronchus might be deformed by compression from great vessels due to sternal depression.

METHODS

A retrospective cohort study included 36 patients with pectus excavatum, who were treated using the Nuss procedure between July 2001 and December 2009. The primary outcome measures were the oblateness of the trachea and bilateral main bronchus. The oblateness in patients with pectus excavatum was compared with that of the control group. Their postoperative changes and the relationship between the Haller CT index were also analyzed.

RESULTS

The oblateness of the trachea and the left main bronchus in patients with pectus excavatum was significantly greater than that of the control group. A negative correlation was recognized between the percent vital capacity and the oblateness of the left main bronchus. The oblateness of the bilateral main bronchus significantly improved during the 2 years of bar placement.

CONCLUSION

A significant deformation of the airways was demonstrated in patients with pectus excavatum, which improved after correcting it by means of the Nuss procedure.

Pectus excavatum: historical background, clinical picture, preoperative evaluation and criteria for operation

Pectus excavatum is a depression of the sternum and costal cartilages which may present at birth, or more commonly during the teenage growth spurt. Symptoms of lack of endurance, shortness of breath with exercise, or chest pain are frequent. Although pectus excavatum may be a component of some uncommon syndromes, patients usually are healthy. Evaluation should include careful anatomic description with photographs, radiography to demonstrate the depth of the depression, extent of cardiac compression, or displacement, measurement of pulmonary function, and echocardiography to look for mitral valve prolapse (in 15%) or diminished right ventricular volume. Indications for surgical treatment include two or more of the following: a severe, symptomatic deformity; progression of deformity; paradoxical respiratory chest wall motion; computer tomography scan with a pectus index greater than 3.25; cardiac compression/displacement and/or pulmonary compression; pulmonary function studies showing restrictive disease; mitral valve prolapse, bundle branch block, or other cardiac pathology secondary to compression of the heart; or failed previous repair(s). The developmental factors, genetics, and physiologic abnormalities associated with the condition are reviewed.

Demonstrating relief of cardiac compression with the Nuss minimally invasive repair for pectus excavatum

BACKGROUND/PURPOSE

Anatomic and physiological parameters have not been routinely used in the preoperative and postoperative evaluation of pectus excavatum. Most symptomatic patients have had significant subjective improvement after pectus correction. This study is based upon the use of noninvasive upright echocardiography/electrocardiogram (echo/EKG) with exercise to both identify and provide evidence of correction of cardiac abnormalities resulting from pectus excavatum.

METHODS

One hundred twenty-three patients, 99 males and 24 females, ages 5 to 18 years (average, 13 years) underwent Nuss pectus repair. A retrospective review of their medical records was performed.

RESULTS

Symptoms related to exertion were present in 106 (86%). The mean Haller chest wall index (CWI) was 4.3 (2.4-10.85). Preoperative echo/EKG with exercise revealed cardiac compression in 117 (95%). A mitral valve abnormality was present in 54 (44%). Six children had no chamber compression but mitral valve prolapse was present in 2 and significant arrhythmias in 4. All patients were asymptomatic after surgery. Postoperative echo/EKG with exercise was performed in 107 (87%). The postoperative echo/EKG was normal in 100 (93% of those studied). Mild persistent mitral valve prolapse existed in 7. There were no postoperative arrhythmias. Twelve (9.8%) patients with low CWI (<3.25) were relieved of chamber compression and had no postoperative arrhythmia. Patent ductus was discovered in 2 patients on their postoperative echos. One closed spontaneously. A child with Marfan syndrome required interventional occlusion.

CONCLUSION

Noninvasive echo/EKG with exercise is beneficial in the evaluation of patients with pectus excavatum and provides objective evidence of improvement postoperatively. It is especially valuable as a physiological indicator of cardiac abnormality in patients with a CWI below 3.25. Patients with mitral valve prolapse need long-term follow-up.

Pectus excavatum in a 112-year autopsy series: anatomic findings and the effect on survival

BACKGROUND/PURPOSE

The purpose of this study was to determine the frequency of pectus excavatum and associated conditions in a large autopsy series. It also sought to determine whether there were different survival patterns for pectus excavatum patients than for patients without pectus excavatum.

METHODS

A computer-assisted search of autopsy files maintained by Johns Hopkins University was conducted, dating from 1889 to 2001. Each patient's Autopsy Pathology Information System report was reviewed for diagnosis and comorbid conditions. To determine whether there were differences in survival patterns, we tested whether pectus excavatum patients survived longer than controls, using a standard epidemiological method. Each patient in the autopsy series was compared with the 2 patients entered in the autopsy database chronologically immediately before and the 2 patients immediately after the case. A Kaplan-Meier survival analysis was conducted.

RESULTS

Pectus excavatum was identified at autopsy in 62 of 50,496 cases. Of these 62 patients, 17 were 65 years or older and appeared to have died of causes unrelated to pectus excavatum, the oldest being 91 years. Twenty-one were between the ages of 14 and 65 years and were found to have coexisting conditions or syndromes. Six were between the ages of 1 and 4 years. One of the 6 died in 1947 because of complications from pectus repair. No autopsied patient with pectus excavatum died between the ages of 5 and 14 years. Eighteen were infants younger than 1 year, and all 18 died because of conditions unrelated to pectus excavatum. There were no reported cases of pectus excavatum before 1947, and the severity of deformity could not be determined from the autopsy data. Survival analysis indicated that pectus excavatum patients had a different survival than the controls. Pectus excavatum patients tended to die earlier (P = .0001). However, pectus excavatum patients who survived past the age of 56 years tended to survive longer than their matched controls (P = .0001).

CONCLUSION

Although there were no histological abnormalities noted in the cartilage of the pectus excavatum patient's conditions, pectus excavatum was associated with several connective tissue abnormalities. Analysis is consistent with the theory that this condition can impact survival.

New insights into degenerative mitral valve disease in dogs

Degenerative mitral valve disease (DMVD) is the most common cardiac disease in dogs. Although the disease is frequently described in the veterinary literature, many aspects are still unknown or controversial. Based on recent research findings, this article addresses the etiology, pathogenesis, inheritance, diagnosis of early DMVD, diagnosis of mild decompensated heart failure, and efficacy of early medical intervention in clinically compensated dogs.

Ventilatory and cardiovascular responses to exercise in patients with pectus excavatum

PURPOSE

Uncertainty exists as to whether pectus excavatum causes true physiologic impairments to exercise performance as opposed to lack of fitness due to reluctance to exercise. The purpose of this study was to examine the effect of pectus excavatum on ventilatory and cardiovascular responses to incremental exercise in physically active patients.

METHODS

Twenty-one patients with pectus excavatum (age range, 13 to 50 years; mean [+/- SD] age, 23.6 +/- 8.9 years; severity index range, 3.7 to 8.0; mean severity index, 5.1 +/- 1.2) were referred for preoperative evaluation. Eighteen of the patients (85%) had a history of performing aerobic activity ranging from 30 min to 2 h per day (mean duration, 1.0 +/- 0.61 h per day) for 3 +/- 1.5 days per week. Patients performed pulmonary function tests, and submaximal and maximal incremental exercise testing.

RESULTS

On maximal exercise testing, the maximum oxygen uptake (O(2)max), and oxygen-pulse were significantly lower than the reference values (t(20) = 6.17 [p < 0.0001] and t(20) = 4.52 [p < 0.0001], respectively). Furthermore, patients exhibited cardiovascular limitation, but not ventilatory limitation. Despite their high level of habitual exercise activity, the overall metabolic threshold for lactate accumulation was abnormally low (ie, 41% of the reference value for O(2)max) especially in those with a pectus severity index (PSI) of > 4.0 (39% of the reference value of O(2)max), which is consistent with cardiovascular impairment rather than physical deconditioning. Patients with a PSI of > 4.0 were also eight times more likely to have reduced aerobic capacity than patients who had a low severity index, despite their level of exercise participation. On submaximal testing, we found that the time constant for O(2) uptake kinetics was 37.4 s for the on-transit and 41.6 s for the off-transit. The observed values for FVC, FEV(1), maximum voluntary ventilation, and diffusing capacity of the lung for carbon monoxide were significantly lower than reference values, but those for total lung capacity and residual volume were not significantly lower than reference values.

CONCLUSIONS

The information derived from this study supports the opinion that pectus excavatum is associated with true physiologic impairment and reduced exercise capacity, predominantly due to impaired cardiovascular performance rather than ventilatory limitation. Furthermore, the impairment is not explained by physical deconditioning.