Background Although standardized clinical guidelines are lacking, structured exercise training (ExT) can safely improve cardiorespiratory fitness and clinical outcomes after internal carotid artery dissection (ICAD) in persons with vascular Ehlers-Danlos syndrome (vEDS). Case Summary We implemented progressive ExT in a 19-year-old man with vEDS after he experienced separate, bilateral ICADs that occurred 12 months apart. The individualized ExT plan included in-clinic and at-home low- to moderate-intensity aerobic and resistance exercise. Discussion Provider reluctance to prescribe exercise because of tissue fragility and risk of arterial rupture, combined with patient kinesiophobia, often leads people with vEDS to limit physical activity, especially after ICAD. Such patients require education and guidance to safely self-monitor and adhere to ExT. Take-Home Messages This case demonstrates the feasibility and benefit of structured ExT after ICAD in a person with vEDS. It highlights the need to further develop evidence-based guidelines for ExT in this population.

PURPOSE:This study aimed to investigate the relationships between the dose of post-lung transplantation (LTx) pulmonary rehabilitation (PR) and exercise capacity, rehospitalization, and survival in LTx recipients. METHODS:Demographic and clinical data of LTx recipients from January 2020 to April 2023 were extracted and reviewed. The association between PR and the pre- to post-PR change in 6-minute walk test distance (6MWTd) was determined using lasso regression for variable selection followed by multiple linear regression. The association between the number of PR sessions completed and rehospitalization and survival after LTx was determined using negative binomial regression and Cox proportional hazards models. RESULTS:Aerobic training volume was a significant independent predictor of 6MWTd improvement from pre- to post-PR (β = .318, P < .001). Each additional PR session was associated with a 4.7-m greater 6MWTd (P = .010), a 3.8% lower rate of rehospitalization within 1 year of transplantation (IRR = 0.962, P = .078), and a 9.0% lower mortality risk (HR = 0.910, P = .052). Completing 16 to 27 PR sessions was associated with a 48% lower rehospitalization rate (IRR = 0.518, P =.037) and a 73% lower mortality risk (HR = 0.266, P = .071) compared with completing 1 to 11 sessions. CONCLUSIONS:Greater aerobic training volume was an independent predictor of improved exercise capacity, while a greater number of PR sessions was associated with fewer total rehospitalizations within 1 year of LTx and a trend toward improved survival.

By reading this article, you will:center dot Understand how commonly used cardiorespiratory fitness prediction equations can misclassify fitness in both high-performance and clinical populations.center dot Learn how common prediction equations were developed and why the population of prediction equation studies matters when interpreting estimated cardiorespiratory fitness and percent-predicted values.center dot Recognize how to critically assess the suitability of a given cardiorespiratory fitness equation based on your client's or patient's characteristics.

Inspiratory muscle fatigue develops during exercise before intolerance. The expiratory muscles are less resistant to fatigue compared to the inspiratory muscles, but the time course of inspiratory and expiratory muscle fatigue during exercise has not been compared. Ten healthy adults (25 ± 5 yr; 2 females) cycled on three separate occasions at 25% of the difference between estimated critical power and peak ramp incremental power (severe intensity domain) for 1) 100% of time to the limit of tolerance (TLIM; 10.2 ± 2.6 min); 2) 75% TLIM (7.7 ± 1.9 min); and 3) 50% TLIM (5.1 ± 1.3 min). Expiratory and inspiratory muscle fatigue were quantified as the pre- to postexercise reduction in the gastric (Pgatw) and diaphragm (Pditw) twitch pressure response to magnetic stimulation of the thoracic and cervical nerves, respectively. Pgatw and Pditw were reduced from baseline values after 50% TLIM (11.9 ± 8.2% and 9.5 ± 9.2%; both P < 0.05). The magnitude of expiratory and inspiratory muscle fatigue increased progressively at 75% TLIM (20.0 ± 12.6% and 15.2 ± 10.1%; both P < 0.05) and 100% TLIM (30.3 ± 15.6% and 22.4 ± 12.5%; both P < 0.05), but there was no difference between muscle groups (P > 0.05). Expiratory and inspiratory muscle fatigue develops relatively early during severe intensity exercise and increases progressively in magnitude by exercise intolerance. The onset and progression of respiratory muscle fatigue during exercise are not different between the expiratory and inspiratory muscles.NEW & NOTEWORTHY During severe exercise, expiratory and inspiratory muscle fatigue develops by ∼50% of the tolerable exercise duration. The magnitude of expiratory and inspiratory muscle fatigue increases progressively toward exercise intolerance but is not different between muscle groups; this is despite the expiratory muscles being less fatigue-resistant. Inspecting esophageal and gastric twitches via cervical stimulation, we speculate that the progressive magnitude of exercise-induced inspiratory muscle fatigue is a function of recruitment and fatigue of the accessory inspiratory muscles.

Introduction:Ultra-marathon races present a prolonged cardiopulmonary physiological stress but the magnitude, persistence, and impact of race environment on respiratory function are incompletely understood. The aim of this study is to observe the effect of ultra-marathon trail races on both lung function and airway impedance. Methods:Fifty-seven individuals (49/8, M/F) participated in either the Courmayeur-Champex-Chamonix (CCC®, 101.5km), Ultra Trail du Mont-Blanc (UMTB®, 171.5 km), or the Hong Kong 100 (HK, 100 km) races. Participant demographics were measured pre-race and included: age (40.7±10.3 yrs); height (175.5±7.1 cm), body mass (69.7±8.3 kg). Spirometry, airway impedance (via forced oscillation technique, FOT), maximal inspiratory (MIP) and expiratory pressure (MEP), and exhaled nitric oxide (ExNO) were assessed before, immediately (18-4 hours after), and 188-24 hours post-race. Mixed effects analysis with Dunnett's post-hoc correction were conducted to evaluate the effects of race and time. Results:Results demonstrated significant effects of time for: forced vital capacity (FVC), forced expiratory flow over one second (FEV1), peak expiratory flow (PEF), forced expiratory flow between 25-75% (FEF25-75), forced expiratory flow at 25% and at 50% (FEF25 and FEF50, respectively), MIP, MEP, airway reactance (X) at all frequencies from FOT (X5, X11, X19), respiratory rate, and ExNO (all p<0.05). A significant effect of race was also observed for ExNO (p=0.002). Discussion:Findings indicate declines in lung function and airway impedance immediately after ultra-marathon races, some of which, persisted up to 24 hours post-race. Further investigations are required to better understand the etiology of changes in lung function following ultra-endurance events.

OBJECTIVE:Structured exercise training (ExT) has been shown to improve cardiorespiratory fitness and health-related quality of life and is safe in patients after surgery for type A aortic dissection (AD). KEY STEPS:We detail the implementation of progressive ExT in a 56-year-old man former recreational triathlete 16 months after emergency repair of a type I AD, who had a residual descending aortic dissection. A home-based individualized ExT plan incorporated low- to moderate-intensity aerobic and resistance exercise with progression to interval training. POTENTIAL PITFALLS:Exercise is often limited or withheld in patients with previous AD because of concern that sudden blood pressure elevation may increase the risk of recurrent dissection or propagation of existing dissection. Patients, once medically optimized, need proper education to safely self-monitor and adhere to ExT. TAKE-HOME MESSAGE:This case illustrates the potential feasibility, benefit, and safety of exercise after AD, and demonstrates the need to establish evidence-based guidelines.

PURPOSE:Despite the 2022 American Heart Association/American College of Cardiology guidelines recommending cardiac rehabilitation (CR) after aortic dissection repair, both patient participation in CR and the associated clinical outcomes remain poorly understood. METHODS:Adults (≥18 years of age) discharged alive following thoracic aortic dissection surgery across the Mayo Clinic Enterprise (January 2012 to November 2022), with follow-up until May 2024, were included (IRB #24-001141). Data were presented using summary statistics and logistic regression modeling. RESULTS:A total of 186 patients were referred; 37% were female, and the median age was 64 (51, 73) years. Dissections were classified as type A (43%), type B (18%), or a combination, and 55% had residual dissection. Over half (53%) did not start CR, with older age (aOR = 0.97: 95% CI, 0.94 - 0.99; P = .003), family history of aortic dissections and/or aneurysms (aOR = 0.17: 95% CI, 0.04 - 0.54; P = .005), and tobacco use (aOR = 0.35: 95% CI, 0.13 - 0.91; P = .037) being associated with lower odds of enrollment. Of the 87 who enrolled, 34 did so at a Mayo Clinic facility. There were no complications, with no difference in adverse outcomes. Among those with evaluations at graduation from CR (n = 21), quality of life (Dartmouth index 16 [14, 19] vs 25 [22, 30]; P = .002) and 6-minute walk distance (488 [375, 531] vs 302 [235, 398] m; P = .001) improved. CONCLUSIONS:Following thoracic aortic dissection repair, CR significantly improved quality of life and functional capacity without adverse events. Further work is needed to improve enrollment and establish data-driven safety margins for exercise.

Breath-hold diving poses significant physiological challenges to maintaining O2 homeostasis. During a maximal breath-hold, numerous, subsequently augmenting, involuntary respiratory muscle contractions against a closed glottis (i.e., involuntary breathing movements, IBMs) may elicit respiratory muscle fatigue, especially under conditions of arterial hypoxemia. Thus, the purpose of this study was to determine whether respiratory muscle fatigue occurs following a series of static breath-holds in 14 trained male divers. To do so, we measured transdiaphragmatic twitch pressure (PDI,TW), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) before and 8 min after three preparatory breath-holds (separated by 2.5 min; average duration = 185 ± 69 s and range = 62-309 s) and three maximal breath-holds (separated by 5 min; average duration = 308 s and range = 179-733 s). We calculated a pseudo O2 delivery as heart rate × peripheral O2 saturation. There was a significant reduction of PDI,TW following the breath-hold series (-8.5 ± 13.7%; range: +7 to (-37)%; P = 0.03). Similarly, we found that MIP and MEP decreased by 6.3 ± 10.6% (P = 0.04) and 8.6 ± 10.4% (P = 0.002), respectively. Using an individualized means of determining the presence of fatigue, we observed that some (∼50%), but not all divers incurred respiratory muscle fatigue. Those who developed fatigue had a lower pseudo O2 delivery during the struggle phase than those who did not (P = 0.01). Our findings suggest that respiratory muscle fatigue was more common in those divers who experienced a greater severity of arterial hypoxemia during the breath-holding protocol.NEW & NOTEWORTHY Respiratory muscle fatigue could occur following involuntary breathing movements during maximal breath-holds. We measured respiratory muscle strength pre and post three preparatory and maximal breath-holds. We found significant reductions in diaphragm strength and total inspiratory and expiratory strength in some, but not all, divers. Divers that had respiratory muscle fatigue had a lower pseudo O2 delivery (HR × [Formula: see text]) during the struggle phase. This suggests that reduced oxygen delivery may contribute to respiratory muscle fatigue during a breath-hold.

To examine the pathophysiology, clinical presentation, early recognition, and prevention of immersion pulmonary edema (IPE) in swimmers and divers. Additionally, we give specific attention to tactical athletes who face unique occupational exposures. IPE is increasingly recognized in both elite and recreational athletes. Risk factors include cold water immersion, vigorous activity, and underlying cardiovascular conditions. Emerging data suggest elevated pulmonary artery and left-sided filling pressures during exertion are the key factors in developing IPE and highlight the potential utility of pulmonary vasodilators (e.g., sildenafil) to mitigate its occurrence. Optimized hydration and physical fitness coupled with medical screenings appear critical to reducing IPE risk. IPE poses significant risks, particularly during high-intensity exercise and/or cold-water environments. Early recognition and preventative strategies, including cardiovascular screening and education, are essential. Further research on pathophysiology, risk factors, and treatments will help improve outcomes and guide safety protocols for at-risk populations, especially tactical divers and endurance athletes.

Background: Cardiac rehabilitation (CR) is essential to secondary cardiovascular disease prevention and management of cardiac patients. Despite its proven benefits, CR remains underutilized with enrollment and completion rates ranging from 10-30% in the US. Yet, there is a scarcity of nationally representative data among diverse populations on socioeconomic differences in barriers and beliefs of CR participation and delivery mode preferences. Hypothesis: The perceptions (barriers, beliefs), CR delivery mode preferences, and CR utilization (prior enrollment) varies by socioeconomic status (SES) among CR-eligible individuals. Methods: We conducted an anonymous national electronic survey from March 2023 to January 2024 of individuals self-reporting a prior CR-eligible diagnosis. The 22-item CR Barriers Scale assessed perceived barriers to CR enrollment and participation using a 5-point Likert scale (strongly disagree to strongly agree). A 13-item, validated questionnaire assessed 4 subscales pertaining to patients’ beliefs about CR, each rated on a 5-point Likert scale (strongly disagree to strongly agree): perceived necessity, concerns about exercise, practical barriers and perceived suitability. CR delivery mode preferences were ascertained (eg, virtual, at-home, etc.). Mean barriers and belief scores as well as delivery mode preferences were stratified by SES. Low SES was defined as ≤ high school education, Medicaid insurance, or uninsured. High SES was defined as > high school education and non-Medicaid health insurance. Responses were analyzed using descriptive statistics with R software. Results: A total of 466 participants completed the survey (38.1% women, 30.6% minoritized racial/ethnic group, 29.6% low SES, 95% response rate) ( Table 1 ). The majority indicated prior enrollment in CR (81.5%) with no difference by SES. CR barrier scores did not differ significantly by SES (p=0.331) ( Table 2 ). Beliefs about CR perceived necessity and perceived suitability differed by SES (p<0.001 and p=0.025), but beliefs regarding concerns about exercise and practical barriers did not. The low SES group reported a higher preference for completely at-home CR compared to the high SES group (33.6% vs 7.4%, p<0.001). Conclusion: Our findings suggest that CR beliefs varied by SES while utilization did not. For CR-eligible patients experiencing socioeconomic disadvantage, at-home CR may be a preferred alternative to center-based CR to increase CR participation and adherence.

Background: Despite expert opinion recommending patient-tailored cardiac rehabilitation (CR) after acute aortic dissection, both patient participation in CR and the associated risk factor modification after CR following aortic dissection repair are poorly understood. Objectives: To describe the characteristics of patients referred to CR, as well as the enrollment rate and outcomes of those referred to CR following thoracic aortic dissection. Methods: We reviewed electronic health records of adults (≥18) discharged alive following thoracic aortic dissection surgery across the Mayo Clinic Enterprise (01/01/2020-11/15/2022) with follow-up to 05/15/2024 (IRB #24-001141). Data are presented using summary statistics. Results: During the study period, 85 patients were included (median [IQR] age: 65 [50-75] years; 40% female; Table 1 ). Across 84% (N=71) who were referred to CR at discharge, 55% (N=39) enrolled. In those patients referred versus not referred to CR, the prevalence of type A dissection (75% vs. 43%), end-organ involvement (27% vs. 0%), and underlying CAD (54% vs. 21%) were greater while current tobacco use (9% vs. 29%) was lower. Of those enrolled at Mayo Clinic (N=16), CR was started 35 (28-65) days following surgery. These patients completed 21 (13-30) CR sessions at an exercise intensity of 59% (50-65%) maximum predicted heart rate. CR was discontinued in 44% (N=7) due to non-cardiac reasons ( Table 2 ). Of the 9 patients who completed CR, general health status (Dartmouth index: 19 [17-21] vs. 26 [22-34]), depressive symptoms (PHQ-9: 1 [0-1] vs. 4 [1-4]), and exercise capacity (6MWT: 214 [196-244] vs. 384 [305-597] meters) improved ( Table 2 ). There were no reported complications or deaths, with stable aortic sizes reported at 18 months. Conclusions: CR improves functional capacity and well-being without complications in patients after thoracic aortic dissection surgery. Further investigation is needed to better assess CR efficacy and usage in this population.

This manuscript examines how mobile health (mHealth) applications (apps) can enhance patient engagement in cardiac rehabilitation (CR). This review addresses two key questions: (1) how can mHealth apps augment traditional center-based CR (CBCR) programs, and (2) how can they be used to provide an alternative model for home-based CR (HBCR) programs? By evaluating recent mHealth advancements, we discuss integrating these digital tools into CR programs to increase patient engagement. Recent studies have highlighted the multifaceted role of mHealth apps in CR. mHealth apps can significantly enhance CBCR programs by engaging patients in the collection of their health care data, increasing patient self-management of disease, and facilitating communication between patients and their care teams. Additionally, they support remote CR delivery through HBCR models, termed mHealth-CR, particularly in areas where CBCR facilities are less accessible. Recent studies indicate that mHealth-CR programs improve patient adherence and participation, likely by addressing logistical barriers like transportation and scheduling conflicts. Integrating mHealth applications into CR can enhance patient engagement with and attendance of CBCR programs. They offer a solution to the underutilization and capacity limitations of CBCR programs. Further research is needed to optimize mHealth implementation and evaluate long-term outcomes. These digital tools could reshape CR services, making them more inclusive and accessible, but careful consideration is needed to prevent exacerbating healthcare inequalities and the “digital divide.”

INTRODUCTION:Endurance exercise at altitude can increase cardiac output and pulmonary vascular pressure to levels that may exceed the stress tolerability of the alveolar-capillary unit. This study examined the effect of ultramarathon trail racing at different altitudes (ranging from <1000 m to between 1500 and 2700 m) on alveolar-capillary recruitment and lung diffusion. METHODS:Cardiac and lung function were examined before and after an ultramarathon in 67 runners (age: 41 ± 9 yr, body mass index: 23 ± 2 kg·m -2 , 10 females), and following 12-24 h of recovery in a subset ( n = 27). Cardiac biomarkers (cTnI and BNP) were assessed from whole blood, whereas lung fluid accumulation (comet tails), stroke volume (SV), and cardiac output ( Q ) were quantified via echocardiography. Lung diffusing capacity for carbon monoxide (DLco) and its components, alveolar membrane conductance (Dm) and capillary blood volume (Vc), were determined via a single-breath method at rest and during three stages of submaximal semirecumbent cycling (20, 30, and 40 W). RESULTS:Average race time was 25 ± 12 h. From pre- to post-race, there was an increase in cardiac biomarkers (cTnI: 0.04 ± 0.02 vs 0.13 ± 0.03 ng·mL -1 , BNP: 20 ± 2 vs 112 ± 21 pg·mL -1 ; P < 0.01) and lung comet tails (2 ± 1 vs 7 ± 6, P < 0.01), a decrease in resting and exercise SV (76 ± 2 vs 69 ± 2 mL, 40 W: 93 ± 2 vs 88 ± 2 mL; P < 0.01), and an elevation in Q at rest (4.1 ± 0.1 vs 4.6 ± 0.2 L·min -1 , P < 0.01; 40 W: 7.3 ± 0.2 vs 7.4 ± 0.3 L·min -1 , P = 0.899). Resting DLco and Vc decreased after the race ( P < 0.01), whereas Dm was unchanged ( P = 0.465); however, during the three stages of exercise, DLco, Vc, and Dm were all reduced from pre- to post-race (40 W: 36.3 ± 0.9 vs 33.0 ± 0.8 mL·min -1 ·mm Hg -1 , 83 ± 3 vs 73 ± 2 mL, 186 ± 6 vs 170 ± 7 mL·min -1 ·mm Hg -1 , respectively; P < 0.01). When corrected for alveolar volume and Q , DLco decreased from pre- to post-race ( P < 0.01), and changes in DLco were similar for all ultramarathon events ( P > 0.05). CONCLUSIONS:Competing in an ultramarathon leads to a transient increase in cardiac injury biomarkers, mild lung-fluid accumulation, and impairments in lung diffusion. Reductions in DLco are predominantly caused by a reduced Vc and possible pulmonary capillary de-recruitment at rest. However, impairments in alveolar-capillary recruitment and Dm both contribute to a fall in exertional DLco following an ultramarathon. Perturbations in lung diffusion were evident across a range of event distances and varying environmental exposures.

Background:Few studies have evaluated home-based cardiac rehabilitation (HBCR) during the pandemic, compared to prepandemic center-based CR (CBCR), with respect to patient characteristics, participation rates, and its efficacy on clinical metrics, health-related quality of life (QoL), and modifiable risk factors. Objectives:We aimed to describe patient characteristics and participation rates for those attending HBCR compared to patients who attended CBCR and compare the effects of HBCR vs CBCR on clinical metrics, health-related QoL, and modifiable risk factors in CR patients pre vs during the COVID-19 pandemic. Methods:A retrospective cohort study comparing 511 HBCR patients and 765 CBCR patients from the Mayo Clinic Health System. HBCR included 12 sessions. Conventional CBCR included 36 sessions. Clinical outcomes before and after CR were assessed. Results:The HBCR group demonstrated a smaller proportion of patients referred for coronary artery diseases (45.2% vs 63.3%) than the CBCR group (P < 0.001). The HBCR group participated in 74.5 ± 28.6% of prescribed sessions compared to 67.9% ± 35.7% of prescribed sessions in the CBCR group (P = 0.26). Both groups demonstrated similar improvements in nutrition, depression, QoL, glucose intolerance, and lipid profiles. Conclusions:Patients participating in HBCR during the COVID-19 pandemic demonstrated similar participation rates compared to CBCR. HBCR appears to be similarly effective at improving several intermediate outcomes compared to CBCR. HBCR may be a suitable alternative CR delivery model to increase CR participation for a wide range of clinical indications and improve clinical outcomes in patients who are unable to participate in CBCR.