Strategies for cardiopulmonary exercise testing of pectus excavatum patients

Pectus Excavatum in Cardiac Surgery Patients

BACKGROUND

Pectus excavatum frequently accompanies congenital heart disease and connective tissue diseases requiring cardiac surgery. Sometimes the indication is cardiac repair, with the pectus being incidentally noticed; other times, the pectus subsequently develops or becomes more significant after cardiac surgery. This review arms cardiac and congenital surgeons with background about the physiologic impact of pectus, indications for repair and repair strategies, and outcomes for cardiac surgery patients requiring pectus repair.

METHODS

A comprehensive literature review was performed using keywords related to pectus excavatum, pectus repair, and cardiac/congenital heart surgery within the PubMed database.

RESULTS

The risks of complications related to pectus repair, including in the setting of cardiac surgery or after cardiac surgery, are low in experienced hands, and patients demonstrate cardiopulmonary benefits and symptom relief. Concomitant pectus and cardiac surgery should be considered if it is performed in conjunction with those experienced in pectus repair, particularly given the increased cardiopulmonary impact of pectus after bypass. In the setting of potential bleeding or hemodynamic instability, delayed sternal closure is recommended. For those with anticipated pectus repair after cardiac surgery, the pericardium should be reconstructed for cardiac protection. For those undergoing pectus repair after cardiac surgery without a membrane placed, a "hybrid" approach is safe and effective.

CONCLUSIONS

Patients undergoing cardiac surgery noted to have pectus should be considered for possible concomitant or staged pectus repair. For those who will undergo a staged procedure, a barrier membrane should be placed before chest closure.

Association between maximal aerobic capacity and heart rate variability

Relevance. Сardiovascular status could be assessed by maximal aerobic capacity (VO2max) through direct analysis of the gases involved in pulmonary ventilation and monitoring fluctuations in intervals between beats over time as heart rate variability. The aim of the study was to investigate the relationship between VO2max and heart rate variability in young adults. Materials and Methods. A total of 100 young adults between the ages of 18 and 25 were included in observational study, who did not engage in any strenuous physical activity, 50 of whom were male and 50 of whom were female.There were measured Heart rate variability in the frequency domain; LF, HF, LF/HF, and time domain; SDNN, RMSSD, pNN 50, and VO2max were assessed using a treadmill test according to Graded Exercise Protocol. Results and Discussion. There was weak positive correlation of VO2max with LF ( r = 0.177) and weak negative correlation with HF ( r = -0.141). Male participants had a weak negative relationship between VO2 max and LF ( r = -0.075), whereas female respondents had a weak positive relationship(r = 0.286). There was weak negative correlation of VO2max with LF/HF ratio for male subjects but weak positive correlation ( r = -0.101) for female subjects. For male and female participants, there was a weak negative association of VO2max with SDNN ( r = -0.170) and ( r = -0.301), respectively. Male and female participants had a weak negative association of VO2max with RMSSD, with ( r = -0.154) and ( r = -0.284) respectively. Male and female participants had a slight negative association of VO2max with pNN 50, with ( r = -0.062) and ( r = -0.441) respectively. Conclusion. Significant variations were found in the time domain and frequency domain indices including HF and LF/HF ratio which represents the balance between sympathetic and parasympathetic responses.

Cardiopulmonary Outcomes After the Nuss Procedure in Pectus Excavatum

Background

Pectus excavatum is the most common chest wall deformity. There is still controversy about cardiopulmonary limitations of this disease and benefits of surgical repair. This study evaluates the impact of pectus excavatum on the cardiopulmonary function of adult patients before and after a modified minimally invasive repair.

Methods and Results

In this retrospective cohort study, an electronic database was used to identify consecutive adult (aged ≥18 years) patients who underwent cardiopulmonary exercise testing before and after primary pectus excavatum repair at Mayo Clinic Arizona from 2011 to 2020. In total, 392 patients underwent preoperative cardiopulmonary exercise testing; abnormal oxygen consumption results were present in 68% of patients. Among them, 130 patients (68% men, mean age, 32.4±10.0 years) had post‐repair evaluations. Post‐repair tests were performed immediately before bar removal with a mean time between repair and post‐repair testing of 3.4±0.7 years (range, 2.5–7.0). A significant improvement in cardiopulmonary outcomes (P<0.001 for all the comparisons) was seen in the post‐repair evaluations, including an increase in maximum, and predicted rate of oxygen consumption, oxygen pulse, oxygen consumption at anaerobic threshold, and maximal ventilation. In a subanalysis of 39 patients who also underwent intraoperative transesophageal echocardiography at repair and at bar removal, a significant increase in right ventricle stroke volume was found (P<0.001).

Conclusions

Consistent improvements in cardiopulmonary function were seen for pectus excavatum adult patients undergoing surgery. These results strongly support the existence of adverse cardiopulmonary consequences from this disease as well as the benefits of surgical repair.

Supervised Cycling Training Improves Erythrocyte Rheology in Individuals With Peripheral Arterial Disease

Peripheral arterial disease (PAD) results in insufficient flow to lower extremities. Aerobic exercise provides health benefits for individuals with PAD, but basic science behind it is still debated. Twenty-one PAD patients aged about 70 years with female/male as 7/14 were recruited. Among them, 11 were randomized to have supervised cycling training (SCT) and 10 to receive general healthcare (GHC) as controls. SCT participants completed 36 sessions of SCT at the first ventilation threshold within 12 weeks and the controls received GHC for 12 weeks. Ankle-brachial index (ABI), 6-min walk test (6MWT), peak oxygen consumption (V˙O_2peak), minute ventilation (V˙_E), minute carbon dioxide production (V˙CO₂), erythrocyte rheology, including the maximal elongation index (EI_max) and shear stress at 50% of maximal elongation (SS_1/2), and the Short Form-36 (SF-36) questionnaire for quality of life (QoL) were assessed before and 12 weeks after initial visit. SCT significantly decreased the SS_1/2 as well as SS_1/2 to EI_max ratio (SS_1/2/EI_max) and increased the erythrocyte osmolality in the hypertonic region as well as the area under EI-osmolality curve. The supervised exercise-induced improvement of erythrocyte deformability could contribute to the increased peripheral tissue O₂ delivery and was possibly related with increased V˙O_2peak. The physiological benefit was associated with significantly increased ABI, 6-min walking distance, cardiorespiratory fitness, and SF-36 score. However, no significant changes in aerobic capacity and erythrocyte rheological properties were observed after 12-week of GHC. In conclusion, SCT improves aerobic capacity by enhancing erythrocyte membrane deformability and consequently promotes QoL in PAD patients.

The Evolution of the Physical Work Capacity at the Fatigue Threshold Test: Past, Present, and Future

ABSTRACT

Feldpausch, JE, Blok, AL, Frederick, EL, Coburn, JW, and Malek, MH. The evolution of the physical work capacity at the fatigue threshold test: past, present, and future. J Strength Cond Res 35(12): 3529-3536, 2021-The assessment of neuromuscular fatigue using surface electromyography has evolved over the past 40 years while maintaining some of the original key features. In this mini-review article, the goal will be to briefly present a history and systems of the physical working capacity at the fatigue threshold (PWCFT). In addition, we will discuss studies that have investigated the effect of different interventions such as supplementation, exercise, and cognitive fatigue to examine what stimuli influence the PWCFT. The latter section of this mini-review will discuss future studies that may provide additional information related to the underlying physiological mechanism(s) that influences the PWCFT. We will conclude with the practical application of PWCFT in health and sports settings.

Acute Pulmonary Edema Induced by a Low Dose of Ritodrine Hydrochloride: A Case Report

OBJECTIVE

Acute pulmonary edema associated with ritodrine hydrochloride is a rare, life-threatening complication, and dose and duration of ritodrine use are closely associated with this pathology. We report a case of acute pulmonary edema associated with short-duration infusion of ritodrine hydrochloride in a patient with pectus excavatum as an underlying factor.

CASE REPORT

A 30-year-old healthy pregnant woman was treated with oral ritodrine for tocolysis between 31 and 35 weeks of pregnancy. At 36 weeks of gestation, she went into preterm labor, with premature rupture of the membrane and breech presentation, and received an infusion of ritodrine hydrochloride for a few hours. Although she was normotensive until labor onset, mild hypertension and proteinuria were recognized. Intraoperatively, a funnel-chest deformity was observed, and she developed postoperative pulmonary edema associated with dyspnea and wet cough and confirmed on chest radiography and arterial gas analysis, and recovered with supportive care.

CONCLUSION

Small-dose infusion of ritodrine hydrochloride might cause pulmonary edema in patients with underlying medical problems, including pectus excavatum.

Improvement of cardiopulmonary function after minimally invasive surgical repair of pectus excavatum (Nuss procedure) in children

Background:

Severe pectus excavatum in children may result in cardiorespiratory functional impairment; therefore, we evaluated cardiopulmonary response to exercise before and after the Nuss procedure.

Methods:

Twenty-four physically active pediatric patients aged 9–18 years with severe pectus excavatum (Haller index >3.25) were included in the study. Cardiopulmonary exercise testing using treadmill and modified Bruce protocol was performed before and after the Nuss procedure.

Results:

Maximal oxygen uptake and oxygen pulse improved by 40.6% (32 ± 13–45 ± 10 ml/kg/min; P = 0.0001) and 44.4% (9 ± 4–13 ± 5 ml/beat; P = 0.03), respectively, after surgical correction of pectus excavatum by Nuss procedure. Significant improvement in maximum voluntary ventilation and minute ventilation after Nuss procedure was also noted.

Conclusions:

We found that, after repair of pectus excavatum by Nuss procedure, the exercise capacity as measured by maximal oxygen consumption improved significantly primarily due to increase in oxygen pulse, an indirect measurement of stroke volume.

Outcomes in adult pectus excavatum patients undergoing Nuss repair

Pectus excavatum (PEx) is one of the most common congenital chest wall deformities. Depending on the severity, presentation of PEx may range from minor cosmetic issues to disabling cardiopulmonary symptoms. The effect of PEx on adult patients has not been extensively studied. Symptoms may not occur until the patient ages, and they may worsen over the years. More recent publications have implied that PEx may have significant cardiopulmonary implications and repair is of medical benefit. Adults presenting for PEx repair can undergo a successful repair with a minimally invasive "Nuss" approach. Resolution of symptoms, improved quality of life, and satisfying results are reported.

Artigos publicados em periódicos brasileiros de interesse para a medicina do exercício e do esporte: uma revisão

Esta nova série de 34 artigos tem por objetivo levar aos leitores nacionais e internacionais algumas das mais importantes contribuições recentes provenientes da literatura médica brasileira de outras especialidades. São trabalhos que podem oferecer suporte a muitas linhas de pesquisa nessa área. Os artigos originais mais relevantes são selecionados por experientes editores, a quem solicitamos a escolha das palavras-chave para que sejam destacadas a fim de chamar a atenção do leitor. Para facilitar a leitura, os artigos são organizados por área de interesse. Para aproveitar ao máximo o limitado espaço editorial, não são incluídos os nomes dos autores dos artigos. O resultado final traz o que há de melhor do artigo, segundo a opinião dos autores com sintética interpretação pessoal. Endereçado ao médico ocupado, esperamos que esta iniciativa possa contribuir para o sucesso da translação do conhecimento da evidência científica para a prática clínica e permita a localização rápida de trabalhos de interesse específico do leitor

A case of right ventricular dysfunction caused by pectus excavatum

Pectus excavatum compresses the underlying right side of the heart, which might lead to right ventricular dysfunction as illustrated in this case report.