Noninvasive assessment by pulsed Doppler ultrasound of left ventricular filling behavior in long distance runners during marathon race

Acute effects of long-distance races on heart rate variability and arterial stiffness: A systematic review and meta-analysis

This study systematically reviewed and quantified the effects of running a long-distance race (LDR) on heart rate variability (HRV) and arterial stiffness (AS). All types of races of a distance equal to or greater than a marathon (≥42.2 km) were included. A total of 2,220 articles were identified, 52 were included in the qualitative analysis, and 48 were meta-analysed. The standardised mean difference pre- and post-race of various time-domain and frequency-domain indices of HRV, mean arterial blood pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP) and carotid-femoral pulse wave velocity (cfPWV) was calculated. Regarding HRV, there was a significant decrease in most of the variables considered as markers of parasympathetic activity, indicating a shift of autonomic balance towards a reduced vagal tone. Regarding vascular variables, there was a significant drop in blood pressure and reduced AS. In conclusion, running an LDR seems to have a considerable acute effect on the autonomic nervous system, haemodynamics, and vascular properties. The observed effects could be categorised within the expected acute responses to long-lasting, strenuous exercise.

Echocardiography to Measure Fitness of Elite Runners

We evaluated the echocardiograms of 134 male and 54 female elite runners who competed over different distances to observe cardiac enlargement and differences among athletes engaged in different types of training, and to relate the echographic dimension with running performance. In male runners, left ventricular (LV) internal diameter at end diastole (LVIDd), LV mass, and left atrial diameter were increased by the length of distance ( P < .001) whereas right ventricular diameter was increased only in marathon runners. In female runners, this association was found when LVIDd, LV mass, and left atrial diameter were adjusted for body surface area ( P < .001). Wall thickness was not related to distance running. Abnormal LV dilation was associated with a low LV ejection fraction for the higher values of LVIDd, but not for the higher indexed LVIDd values. In male runners, LVIDd was associated with 100 m ( r = -0.67, P < .01), 10,000 m ( r = -0.70, P < .001), and marathon ( r = -0.54, P < .001) and in female runners with a 400-m ( r = -0.84, P < .001) race time. These results show that sprint- and endurance-trained runners had an eccentric hypertrophy and that it is necessary to establish a new upper limit of abnormal cavity dilatation as indexed LVIDd. The normal systolic function and the relationship between LVIDd and performance indicate that LV enlargement in elite runners is a physiologic adaptation and that echocardiographic assessment can be used to determine the fitness of runners.

The athlete's heart. A meta-analysis of cardiac structure and function

BACKGROUND

It has been postulated that depending on the type of exercise performed, 2 different morphological forms of athlete's heart may be distinguished: a strength-trained heart and an endurance-trained heart. Individual studies have not tested this hypothesis satisfactorily.

METHODS AND RESULTS

The hypothesis of divergent cardiac adaptations in endurance-trained and strength-trained athletes was tested by applying meta-analytical techniques with the assumption of a random study effects model incorporating all published echocardiographic data on structure and function of male athletes engaged in purely dynamic (running) or static (weight lifting, power lifting, bodybuilding, throwing, wrestling) sports and combined dynamic and static sports (cycling and rowing). The analysis encompassed 59 studies and 1451 athletes. The overall mean relative left ventricular wall thickness of control subjects (0.36 mm) was significantly smaller than that of endurance-trained athletes (0.39 mm, P=0.001), combined endurance- and strength-trained athletes (0.40 mm, P=0.001), or strength-trained athletes (0.44 mm, P<0.001). There was a significant difference between the 3 groups of athletes and control subjects with respect to left ventricular internal diameter (P<0. 001), posterior wall thickness (P<0.001), and interventricular septum thickness (P<0.001). In addition, endurance-trained athletes and strength-trained athletes differed significantly with respect to mean relative wall thickness (0.39 versus 0.44, P=0.006) and interventricular septum thickness (10.5 versus 11.8 mm, P=0.005) and showed a trend toward a difference with respect to posterior wall thickness (10.3 versus 11.0 mm, P=0.078) and left ventricular internal diameter (53.7 versus 52.1 mm, P=0.055). With respect to cardiac function, there were no significant differences between athletes and control subjects in left ventricular ejection fraction, fractional shortening, and E/A ratio.

CONCLUSIONS

Results of this meta-analysis regarding athlete's heart confirm the hypothesis of divergent cardiac adaptations in dynamic and static sports. Overall, athlete's heart demonstrated normal systolic and diastolic cardiac functions.

Impact of different sports and training on cardiac structure and function

There is overwhelming evidence, particularly from echocardiography, that the heart of competitive athletes may differ from that of nonathletes, matched for age, gender, and body size. A larger left ventricular mass has been shown in athletes performing predominantly dynamic aerobic and anaerobic sports, in athletes engaged in static training, and in players of ball sports. Enlargement of the left ventricular internal diameter was most pronounced and reached about 10% in athletes performing predominantly dynamic sports; mainly strength training athletes had a lesser increase of the internal dimension, which was limited to 2.5%. Also the left ventricular wall appeared to be thickened in all types of athletes compared with controls. In sports with high dynamic and low static demands, wall thickness was proportionate or slightly disproportionate to the size of the internal diameter so that relative wall thickness was not different from controls or slightly increased (predominantly eccentric hypertrophy). In strength athletes, the disproportionate increase of wall thickness averaged about 12% (predominantly concentric hypertrophy). In sports with high dynamic and high static demands and requiring prolonged training, such as cycling, the increases of absolute and relative wall thickness reached 29% and 19% and were more pronounced than in runners (mixed hypertrophy). A plausible interpretation of these results is that the development of so-called eccentric or concentric left ventricular hypertrophy according to the type of sports cannot be regarded as an absolute or dichotomous concept because training regimens and sports activities are not exclusively dynamic or static and because the load on the heart is not purely of the volume or the pressure type. Most studies agree that left ventricular systolic and diastolic function is normal in the athlete at rest, whereas diastolic function seems to be enhanced in the exercising endurance athlete. The consistency of the results of studies on athletes in the competitive and the resting season, of training of sedentary subjects, and of spinal cord-injured patients suggests that variations in physical activity can alter left ventricular structure; genetic factors do not seem to be involved in the size of the left ventricular internal diameter but have to be taken into account to interpret wall thickness.

Impaired left ventricular filling dynamics in patients with angina and angiographically normal coronary arteries: effect of beta adrenergic blockade

OBJECTIVE

To assess exercise performance and resting left ventricular filling dynamics in patients with syndrome X (SX) in basal conditions and after 10 days treatment with oral atenolol.

DESIGN AND PATIENTS

Exercise performance was studied and left ventricular filling assessed by Doppler-derived transmitral flow pattern analysis in 22 patients (16 female, mean (SD) age 53 (4) years) with angina, a positive exercise test, and angiographically smooth coronary arteries. Patients were studied after two 10 day treatment periods with either atenolol or placebo in a single-blind, randomised, crossover trial. The same protocol was followed in 10 patients with documented coronary artery disease (CAD) and in 13 controls (C).

RESULTS

Unlike the controls, patients with SX and those with CAD consistently showed exercise-induced ST segment abnormalities and impaired resting left ventricular filling while on placebo. Atenolol significantly reduced episodes of angina, completely prevented exercise-induced ST segment changes in 18 SX patients, and delayed their onset in all patients with CAD: in both groups the agent significantly improved Doppler-derived indices (mean (SD)) of ventricular filling (E/A 0.97 (0.27) v 1.22 (0.32) and 0.84 (0.21) v 1.19 (0.37), respectively).

CONCLUSIONS

The objective documentation of left ventricular filling abnormalities may be useful in confirming the clinical diagnosis of SX and in providing objective evidence of therapeutic benefit. The similarity of the symptoms and electrocardiographic and ventricular filling abnormalities found in patients with SX and in those with CAD suggests that ischaemia is involved in both groups.

Cardiac anatomy and diastolic filling in professional road cyclists

In the literature two divergent types of exercise-induced cardiac hypertrophy have been described: isotonic exercise induced eccentric hypertrophy with proportional increase in end-diastolic left ventricular dimension and wall thickness and isometric exercise induced concentric hypertrophy with normal end-diastolic left ventricular dimension but increased wall thickness. Using echocardiography, cardiac anatomy and diastolic filling were studied in 26 professional road cyclists. Compared to 21 control subjects, matched according to age, sex and morphometry the athletes had significantly larger left atrial dimension [41.3 (SD 4.8) vs 36.6 (SD 4.5) mm], left ventricular dimension [56.0 (SD 3.8) vs 53.2 (SD 4.7) mm], end-diastolic septum thickness [11.1 (SD 2.5) vs 8.4 (SD 1.9) mm], end-diastolic posterior wall thickness [11.6 (SD 2.2) vs 8.4 (SD 1.5) mm] and left ventricular mass index [170.4 (SD 40.6) vs 107.0 (SD 27.7) g.m-2]. We concluded that the hypertrophy in the road cyclists was of the mixed type (concentric-eccentric) with an increase in the internal dimension of the left ventricle and an even larger increase in the thickness of the ventricular walls. Diastolic filling however was similar in the athletes and control subjects. No correlations were found between the left ventricular mass index and diastolic filling parameters. We concluded therefore that professional road cycling causes mixed cardiac hypertrophy without diastolic filling abnormalities and can therefore be considered benign.