Lukas D. Trachsel

Acute effects of Finnish sauna and cold-water immersion on haemodynamic variables and autonomic nervous system activity in patients with heart failure.

Background The haemodynamic response to Finnish sauna and subsequent cold-water immersion in heart failure patients is unknown. Methods Haemodynamic response to two consecutive Finnish sauna (80℃) exposures, followed by a final head-out cold-water immersion (12℃) was measured in 37 male participants: chronic heart failure (n = 12, 61.8 ± 9.2 years), coronary artery disease (n = 13, 61.2 ± 10.6 years) and control subjects (n = 12, 60.9 ± 8.9 years). Cardiac output was measured non-invasively with an inert gas rebreathing method prior to and immediately after the first sauna exposure and after cold-water immersion, respectively. Blood pressure was measured before, twice during and after sauna. The autonomic nervous system was assessed by power spectral analysis of heart rate variability. Total power, low-frequency and high-frequency components were evaluated. The low frequency/high frequency ratio was used as a marker of sympathovagal balance. Sauna and cold-water immersion were well tolerated by all subjects. Results Cardiac output and heart rate significantly increased in all groups after sauna and cold-water immersion (p < 0.05), except for coronary artery disease patients after sauna exposure. Systolic blood pressure during sauna decreased significantly in all groups with a nadir after 6 min (all p < 0.05). Cold-water immersion significantly increased systolic blood pressure in all groups (p < 0.05). No change in the low/high frequency ratio was found in chronic heart failure patients. In coronary artery disease patients and controls a prolonged increase in low frequency/high frequency ratio was observed after the first sauna exposure. Conclusions Acute exposure to Finnish sauna and cold-water immersion causes haemodynamic alterations in chronic heart failure patients similarly to control subjects and in particular did not provoke an excessive increase in adrenergic activity or complex arrhythmias.

Masked hypertension and cardiac remodeling in middle-aged endurance athletes

Objectives: Extensive endurance training and arterial hypertension are established risk factors for atrial fibrillation. We aimed to assess the proportion of masked hypertension in endurance athletes and the impact on cardiac remodeling, mechanics, and supraventricular tachycardias (SVT). Methods: Male participants of a 10-mile race were recruited and included if office blood pressure was normal (<140/90 mmHg). Athletes were stratified into a masked hypertension and normotension group by ambulatory blood pressure. Primary endpoint was diastolic function, expressed as peak early diastolic mitral annulus velocity (E’). Left ventricular global strain, left ventricular mass/volume ratio, left atrial volume index, signal-averaged P-wave duration (SAPWD), and SVT during 24-h Holter monitoring were recorded. Results: From 108 runners recruited, 87 were included in the final analysis. Thirty-three (38%) had masked hypertension. The mean age was 42 ± 8 years. Groups did not differ with respect to age, body composition, cumulative training hours, and 10-mile race time. Athletes with masked hypertension had a lower E’ and a higher left ventricular mass/volume ratio. Left ventricular global strain, left atrial volume index, SAPWD, and SVT showed no significant differences between the groups. In multiple linear regression analysis, masked hypertension was independently associated with E’ (beta = —0.270, P = 0.004) and left ventricular mass/volume ratio (beta = 0.206, P = 0.049). Cumulative training hours was the only independent predictor for left atrial volume index (beta = 0.474, P < 0.001) and SAPWD (beta = 0.481, P < 0.001). Conclusion: In our study, a relevant proportion of middle-aged athletes had masked hypertension, associated with a lower diastolic function and a higher left ventricular mass/volume ratio, but unrelated to left ventricular systolic function, atrial remodeling, or SVT.

Sports-related sudden cardiac death in Switzerland classified by static and dynamic components of exercise

Background Sports-related sudden cardiac deaths (SrSCDs) occur most frequently in highly dynamic and/or static sports. We aimed to assess the incidence and characteristics of SrSCDs in Switzerland and to compare SrSCD occurrence according to sports categories with the sports participation behaviour in the general population. Methods Between 1999 and 2010, forensic reports of SrSCDs in young individuals (10–39 years of age) were retrospectively reviewed and categorised based on peak static (increasing from I to III) and dynamic sports components (increasing from A to C). Data were compared to the sports participation behaviour of the Swiss population. Results Sixty-nine SrSCDs were identified. Forty-eight (69.6%) occurred during recreational sports (REC) and 21 (30.4%) during competitive sports (COMP). Incidences (per 100,000 athlete person-years) for COMP and REC were 0.90 and 0.52, respectively (p = 0.001). Most SrSCDs occurred in IC (23 cases, 33.3%), followed by IIC (13, 18.9%), IIIA and IIIC (11 each, 15.9%), IIIB (6, 8.7%), IIA (4, 5.8%) and IB sports categories (1, 1.5%). No SrSCDs were found in IA and IIB sports categories. Incidences between sports categories (IIIA 0.25, IB 0.25, IC 0.18, IIC 0.33 and IIIC 0.25) were not significantly different except to IIA (0.94, p < 0.001), due to the fact that few people were involved in this sports category. Coronary artery disease (CAD) was the most common underlying pathology of SrSCD. Conclusions In this Swiss cohort, incidence of SrSCD was very low and similar in all sports categories classified by their static and dynamic components. However, the incidence was higher in COMP compared to REC, and CAD proved to be the most common underlying cause of SrSCD.

Cardiopulmonary adaptation to short-term high altitude exposure in adult Fontan patients

Objective High altitude-related hypoxia induces pulmonary vasoconstriction. In Fontan patients without a contractile subpulmonary ventricle, an increase in pulmonary artery pressure is expected to decrease circulatory output and reduce exercise capacity. This study investigates the direct effects of short-term high altitude exposure on pulmonary blood flow (PBF) and exercise capacity in Fontan patients. Methods 16 adult Fontan patients (mean age 28±7 years, 56% female) and 14 matched controls underwent cardiopulmonary exercise testing with measurement of PBF with a gas rebreathing system at 540 m (low altitude) and at 3454 m (high altitude) within 12 weeks. Results PBF at rest and at exercise was higher in controls than in Fontan patients, both at low and high altitude. PBF increased twofold in Fontan patients and 2.8-fold in the control group during submaximal exercise, with no significant difference between low and high altitude (p=0.290). A reduction in peak oxygen uptake at high compared with low altitude was observed in Fontan patients (22.8±5.1 and 20.5±3.8 mL/min/kg, p<0.001) and the control group (35.0±7.4 and 29.1±6.5 mL/min/kg, p<0.001). The reduction in exercise capacity was less pronounced in Fontan patients compared with controls (9±12% vs 17±8%, p=0.005). No major adverse clinical event was observed. Conclusions Short-term high altitude exposure has no negative impact on PBF and exercise capacity in Fontan patients when compared with controls, and was clinically well tolerated. Trial registration number NCT02237274: Results.

Exercise-induced cardiac remodeling in non-elite endurance athletes: Comparison of 2-tiered and 4-tiered classification of left ventricular hypertrophy

Background Long-term endurance sport practice leads to eccentric left ventricular hypertrophy (LVH). We aimed to compare the new 4-tiered classification (4TC) for LVH with the established 2-tiered classification (2TC) in a cohort of normotensive non-elite endurance athletes. Methods Male participants of a 10-mile race were recruited and included when blood pressure (BP) was normal (<140/90 mmHg). Phenotypic characterization of LVH was based on relative wall thickness (2TC), and on LV concentricity2/3 (LV mass/end-diastolic volume [LVM/EDV]2/3) plus LVEDV index (4TC). Parameters of LV geometry, BP, cumulative training hours, and race time were compared between 2TC and 4TC by analysis of variance, and post-hoc analysis. Results Of 198 athletes recruited, 174 were included. Mean age was 41.6±7.5 years. Forty-two (24%) athletes had LVH. Allocation in the 2TC was: 32 (76%) eccentric LVH and 10 (24%) concentric LVH. Using the 4TC 12 were reclassified to concentric LVH, and 2 to eccentric LVH, resulting in 22 (52%) eccentric LVH (7 non-dilated, 15 dilated), and 20 (48%) concentric LVH (all non-dilated). Based on the 2TC, markers of endurance training did not differ between eccentric and concentric LVH. Based on the 4TC, athletes with eccentric LVH had more cumulative training hours and faster race times, with highest values thereof in athletes with eccentric dilated LVH. Conclusions In our cohort of normotensive endurance athletes, the new 4TC demonstrated a superior discrimination of exercise-induced LVH patterns, compared to the established 2TC, most likely because it takes three-dimensional information of the ventricular geometry into account.

Age at start of endurance training is associated with patterns of left ventricular hypertrophy in middle-aged runners

BACKGROUND Left ventricular hypertrophy (LVH) is a physiological adaptation to long-term endurance training. We investigated the impact of age at start of endurance training on LV geometry in a cohort of male, middle-aged, non-elite endurance athletes. METHODS A total of 121 healthy, normotensive, Caucasian participants of a 10-mile race were recruited and assessed with an echocardiogram and a comprehensive interview. Athletes were classified based on patterns of LVH. RESULTS Thirty-five athletes (31%) had LVH. Athletes with eccentric LVH (16%) were significantly younger at start of endurance training compared to athletes with concentric LVH (15%, 14 ± 5 years vs. 31 ± 8 years; P < 0.001). Although the yearly volume of endurance training was comparable between athletes with eccentric and concentric LVH, athletes with eccentric LVH had shorter race times. All athletes with an increased LV end diastolic volume index (LVEDVI; ≥74 ml/m2) started endurance training before or at age 25. CONCLUSIONS In our cohort of non-elite middle-aged runners, eccentric LVH was found only in athletes with an early start of endurance training. In case of a mature starting age, endurance training may, contrary to what is commonly assumed, also lead to concentric LVH. The consideration of endurance training starting age may lead to a better understanding of morphological adaptations of the heart.

Sports-related sudden cardiac deaths in the young population of Switzerland

Background In Switzerland, ECG screening was first recommended for national squad athletes in 1998. Since 2001 it has become mandatory in selected high-risk professional sports. Its impact on the rates of sports-related sudden cardiac death (SCD) is unknown. Objective We aimed to study the incidence, causes and time trends of sports-related SCD in comparison to SCD unrelated to exercise in Switzerland. Methods We reviewed all forensic reports of SCDs of the German-speaking region of Switzerland in the age group of 10 to 39 years, occurring between 1999 and 2010. Cases were classified into three categories based on whether or not deaths were associated with sports: no sports (NONE), recreational sports (REC), and competitive sports (COMP). Results Over the 12-year study period, 349 SCD cases were recorded (mean age 30±7 years, 76.5% male); 297 cases were categorized as NONE, 31 as REC, and 21 as COMP. Incidences of SCD per 100,000 person-years [mean (95% CI)] were the lowest in REC [0.43 (0.35–0.56)], followed by COMP [1.19 (0.89–1.60)] and NONE [2.46 (2.27–2.66)]. In all three categories, coronary artery disease (CAD) with or without acute myocardial infarction (MI) was the most common cause of SCD. Three professional athletes were identified in COMP category which all had SCD due to acute MI. There were no time trends, neither in overall, nor in cause-specific incidences of SCD. Conclusions The incidence of SCD in young individuals in Switzerland is low, both related and unrelated to sports. In regions, like Switzerland, where CAD is the leading cause of SCD associated with competitions, screening for cardiovascular risk factors in addition to the current PPS recommendations might be indicated to improve detection of silent CAD and further decrease the incidence of SCD.

Effect of phosphodiesterase-5 inhibition with Tadalafil on SystEmic Right VEntricular size and function – A multi-center, double-blind, randomized, placebo-controlled clinical trial – SERVE trial - Rational and design

BACKGROUND Patients with a systemic right ventricle (RV) have a compromised late outcome caused by ventricular dysfunction. Standard medical heart failure therapy has not been shown to improve RV function and survival in these patients. Phosphodiesterase (PDE)-5 inhibition increases contractility in experimental models of RV hypertrophy, but not in the normal RV. In clinical practice, the effects of PDE-5 inhibition on systemic RV function and exercise capacity in adults with a systemic RV have not been tested. METHODS The SERVE protocol is a double-blind, randomized placebo-controlled multicenter superiority trial to study the effect of PDE-5 inhibition with Tadalafil on RV volumes and function in patients with either D-transposition of the great arteries repaired with an atrial switch procedure or with congenitally corrected transposition of the great arteries. Tadalafil 20mg or placebo will be given over a study period of 3years. The primary endpoint is the change in mean end-systolic RV volumes from baseline to study end at 3years of follow-up (or at the time of permanent discontinuation of the randomized treatment if stopped before 3- years of follow-up), and will be measured by cardiovascular magnetic resonance imaging (CMR) or by cardiac computed tomography in patients with contraindications for CMR. Secondary endpoints are changes in RV ejection fraction, VO2max and NT-proBNP. CONCLUSION The objective of this study is to assess the effect of PDE-5 inhibition with Tadalafil on RV size and function, exercise capacity and neurohumoral activation in adults with a systemic RV over a 3-year follow-up period.

Vagal reactivation after exercise and cardiac autonomic nervous activity in adult Fontan patients without pacemakers

PURPOSE Patients with Fontan circulation have reduced heart rate variability (HRV) in supine position. However, neither cardiac autonomic nervous activity (CANA) in response to orthostatic challenge nor vagal reactivation by means of heart rate (HR) recovery after cessation of exercise have previously been investigated in Fontan patients. The aim of this study was to compare HRV in supine and standing position, as well as HR recovery between Fontan patients and healthy controls. METHODS Eight Fontan patients (4 male/4 female) without pacemakers and 12 healthy volunteers (5m/7f) with minimum age of 18years were recruited. HR was measured by Holter-electrocardiogram. HRV was measured in supine position and after orthostatic challenge. The power of the high frequency (HF: 0.15Hz-0.4Hz) and low frequency (LF: 0.04Hz-0.15Hz) bands was analysed by fast-Fourier transformation. HR recovery was determined at 30s and 60s after termination of a maximal exercise test. RESULTS In both supine and standing position, total power, HF and LF power were reduced in Fontan patients compared to controls (by approximately a factor of 10) while there was no differences in LF/HF power ratio. Response to orthostatic challenge was blunted in absolute power but normal in relative power. HR recovery was not different between groups. CONCLUSION Fontan patients have greatly reduced HRV, a blood-pressure dependent marker of CANA, but normal HR recovery, a blood pressure independent marker of vagal reactivation, suggesting that vagal activity may be normal, and only vascular capacitance reduced.

Sports engagement and age at first myocardial infarction in men under 55 years of age

Objective Low levels of physical activity in childhood are associated with clustering of cardiovascular risk factors (CVRF) as predisposition for atherosclerosis. We assessed the association between sports engagement and age at first myocardial infarction (MI) in a cohort of men under 55 years of age. Methods The Bern percutaneous coronary intervention Registry (NCT 02241291) was analyzed from March 2009 until January 2012. Male patients with first MI, age 18 to 54 years and body mass index ≤25kg/m2 were included. Patients were stratified into two groups based on their starting age with organized sports ≥1 h/week outside school (EARLY: <18, CONTROL: ≥18 years or never). We assessed age at time of first MI, CVRF, and volume of sports training. Results Of 4,394 consecutive patients, 123 fulfilled the inclusion criteria (EARLY n = 81, CONTROL n = 42). Age at the time of first MI was 3 years younger in the EARLY compared to the CONTROL group (46.8±6.0 vs. 49.8±4.6 years, p = 0.006). Total lifetime training hours, and average yearly training hours, both, before and after age 18, were significantly greater in the EARLY group. Years of training <18 years were weakly inversely correlated with age at first MI (r2 = 0.075, p = 0.002). The proportion of sports-related MI was not different between EARLY and CONTROL (13.6% vs. 11.9%). Patients in the EARLY group had fewer CVRF (2 vs. 3; p = 0.001). Prevalence of smoking was equally high in both groups (63.0% and 64.3%). Conclusions In our patients aged 54 and younger, the first MI occurred 3 years earlier in those who started regular sports activity before age 18, despite a more active lifestyle and favorable CVRF profile.