Background The aim of the present study was to investigate the effect of a single bout of mild exercise on autonomic nervous system activity in healthy subjects. Methods and Results The study group comprised 18 healthy males, aged between 20 and 24 years, who had not been training regularly for the last 3 months. A supine recording of systolic arterial pressure (SAP) and RR interval and the administration of the phenylephrine test were performed at baseline and repeated after a 60-min recovery period following treadmill exercise training for 30 min at 65% of maximal heart rate. Mean SAP and RR interval, heart rate variability (HRV) indices (the standard deviation of normal-to-normal RR intervals (SDNN), the square root of the mean of squared differences between successive intervals and the percentage of adjacent RR intervals differing more than 50 ms), noninvasive spectral baroreflex sensitivity (Spe-BRS) and phenylephrine baroreflex sensitivity (Phe-BRS) were assessed before and after training. Mean SAP measured after exercise was lower than baseline (120±12 mmHg vs 128±12 mmHg, p=0.05). Spe-BRS and Phe-BRS increased significantly after exercise, from 11.8±6.1 ms/mmHg to 16.0±7.8 ms/mmHg (p=0.034), and from 16.0±8.8 ms/mmHg to 21.9±9.3 ms/mmHg (p=0.022), respectively. A parallel increase was also observed in SDNN (from 81±44 ms to 96±53 ms, p=0.02), but the other HRV indices showed no significant differences between pre- and post-exercise. Conclusions A single session of mild exercise performed by sedentary young men leads to significant autonomic nervous system improvement, which suggests that even mild physical activity is beneficial for neural cardiac regulation and should be recommended to sedentary healthy subjects. (Circ J 2005; 69: 976 - 980)

Background: Endothelial dysfunction is one of the earliest vascular manifestations in the pathogenesis of cardiovascular disease. Noninvasive, simple, and inexpensive methods of endothelial function assessment are therefore needed. Methods: Microvascular endothelial function was assessed in coronary artery disease (CAD) patients by flow mediated skin fluorescence (FMSF), based on measurements of reduced form of nicotinamide adenine dinucleotide (NADH) fluorescence intensity during brachial artery occlusion (ischemic response [IRmax]) and immediately after occlusion (hyperemic response [HRmax]). Additionally, plasma levels of asymmetric dimethylarginine (ADMA) and endothelin-1 (ET-1) were measured to assess the association between biochemical markers and microvascular function evaluated in vivo by FMSF. Results: A significant inverse correlation was found between ADMA levels and hyperemic response (r = -0.534, p = 0.003), while ET-1 levels were inversely related to the ischemic response (r= -0.575, p = 0.001). Both IR and HR were found lowest in patients with advanced CAD and diabetes. When the repeatability of the method was tested, the intraclass correlation coefficient for IRmax and HRmax were 0.985 (p < 0.001) and 0.914 (p < 0.001), respectively. Moreover, in Bland and Altman analysis, both variables IRmax and HRmax showed good agreement in repeated measurements. Conclusions: In this pilot study, it was demonstrated that NADH fluorescence measured by FMSF device in CAD patients was associated with established plasma endothelial markers, and that both ischemic and hyperemic response were blunted in patients with advanced disease and diabetes. Furthermore, FMSF device showed excellent repeatability and good agreement for repeated measurements. However, further study is warranted to confirm these results in a larger patient cohort.

Pulse wave velocity (PWV) is a biomarker for arterial stiffness, clinically assessed by applanation tonometry (AT). Increased use of phase-contrast cardiac magnetic resonance (CMR) imaging allows for PWV assessment with minor routine protocol additions. The aims were to investigate the acquired temporal resolution needed for accurate and precise measurements of CMR-PWV, and develop a tool for CMR-PWV measurements. Computer phantoms were generated for PWV = 2–20 m/s based on human CMR-PWV data. The PWV measurements were performed in 13 healthy young subjects and 13 patients at risk for cardiovascular disease. The CMR-PWV was measured by through-plane phase-contrast CMR in the ascending aorta and at the diaphragm level. Centre-line aortic distance was determined between flow planes. The AT-PWV was assessed within 2 h after CMR. Three observers (CMR experience: 15, 4, and <1 year) determined CMR-PWV. The developed tool was based on the flow-curve foot transit time for PWV quantification. Computer phantoms showed bias 0.27 ± 0.32 m/s for a temporal resolution of at least 30 ms. Intraobserver variability for CMR-PWV were: 0 ± 0.03 m/s (15 years), -0.04 ± 0.33 m/s (4 years), and -0.02 ± 0.30 m/s (<1 year). Interobserver variability for CMR-PWV was below 0.02 ± 0.38 m/s. The AT-PWV overestimated CMR-PWV by 1.1 ± 0.7 m/s in healthy young subjects and 1.6 ± 2.7 m/s in patients. An acquired temporal resolution of at least 30 ms should be used to obtain accurate and precise thoracic aortic phase-contrast CMR-PWV. A new freely available research tool was used to measure PWV in healthy young subjects and in patients, showing low intra- and interobserver variability also for less experienced CMR observers.

Background: Training on a professional level can lead to cardiac structural adaptations called the “athlete’s heart”. As marathon participation requires intense physical preparation, the question arises whether the features of “athlete’s heart” can also develop in recreational runners. Methods: The study included 34 males (mean age 40 ± 8 years) who underwent physical examination, a cardiopulmonary exercise test and echocardiographic examination (ECHO) before a marathon. ECHO results were compared with the sedentary control group, reference values for an adult male population and those for highly-trained athletes. Runners with abnormalities revealed by ECHO were referred for cardiac magnetic resonance imaging (CMR). Results: The mean training distance was 56.5 ± 19.7 km/week, peak oxygen uptake was 53.7 ± 6.9 mL/kg/min and the marathon finishing time was 3.7 ± 0.4 h. Compared to sedentary controls, amateur athletes presented larger atria, increased left ventricular (LV) wall thickness, larger LV mass and basal right ventricular (RV) inflow diameter (p < 0.05). When compared with ranges for the general adult population, 56% of participants showed increased left atrial volume, indexed to body surface area (LAVI), 56% right atrial area and interventricular septum thickness, while 47% had enlarged RV proximal outflow tract diameter. In 50% of cases, LAVI exceeded values reported for highly-trained athletes. Due to ECHO abnormalities, CMR was performed in 6 participants, which revealed hypertrophic cardiomyopathy in 1 runner. Conclusions: “Athlete’s heart” features occur in amateur marathon runners. In this group, ECHO reference values for highly-trained elite athletes should be considered, rather than those for the general population and even then LAVI can exceed the upper normal value. Background: Training on a professional level can lead to cardiac structural adaptations called the “athlete’s heart”. As marathon participation requires intense physical preparation, the question arises whether the features of “athlete’s heart” can also develop in recreational runners. Methods: The study included 34 males (mean age 40 ± 8 years) who underwent physical examination, a cardiopulmonary exercise test and echocardiographic examination (ECHO) before a marathon. ECHO results were compared with the sedentary control group, reference values for an adult male population and those for highly-trained athletes. Runners with abnormalities revealed by ECHO were referred for cardiac magnetic resonance imaging (CMR). Results: The mean training distance was 56.5 ± 19.7 km/week, peak oxygen uptake was 53.7 ± 6.9 mL/kg/min and the marathon finishing time was 3.7 ± 0.4 h. Compared to sedentary controls, amateur athletes presented larger atria, increased left ventricular (LV) wall thickness, larger LV mass and basal right ventricular (RV) inflow diameter (p < 0.05). When compared with ranges for the general adult population, 56% of participants showed increased left atrial volume, indexed to body surface area (LAVI), 56% right atrial area and interventricular septum thickness, while 47% had enlarged RV proximal outflow tract diameter. In 50% of cases, LAVI exceeded values reported for highly-trained athletes. Due to ECHO abnormalities, CMR was performed in 6 participants, which revealed hypertrophic cardiomyopathy in 1 runner. Conclusions: “Athlete’s heart” features occur in amateur marathon runners. In this group, ECHO reference values for highly-trained elite athletes should be considered, rather than those for the general population and even then LAVI can exceed the upper normal value.

The heart is one of the major organs commonly involved in systemic sclerosis (SSc). Myocardial fibrosis has been identified in a high percentage of these patients. Most SSc patients with cardiac involvement (CI) are subclinical, especially early on in the course of their disease. To accurately identify CI and improve diagnosis and treatment, imaging techniques should be implemented on a regular basis following diagnosis. In this review, we discuss the up-to-date pathophysiologic basis of CI, the cardiac manifestations, and the diagnostic methods that have been published in the literature. Recent studies have shown that tissue Doppler imaging is a promising evaluation technique in the bedside detection of CI. Cardiovascular magnetic resonance is an operator-independent method used for detecting SSc CI. It is an especially useful tool in the early stages of the disease when patients may be asymptomatic. At present, it is the most promising imaging technique for the diagnosis, follow-up, and response to therapy in clinical practice.