Young Athletes

Abstract

Objectives

To establish cardiac MRI reference values for endurance athletes and nonathletes, and study the impact of variables related to ventricular volumes and wall-mass.

Methods

Three hundred and thirty-six prospectively recruited healthy individuals aged 18-39 years (mean age 26+/-6 years, 46% women) underwent cardiac MRI: 79 elite athletes (exercising >18 h/week), 143 regular athletes (9-18 h/week), and 114 matched nonathletes (< or =3 h/week).

Results

Body surface area corrected right (RV) and left ventricular (LV) end-diastolic volume (EDV ml/m2) and wall mass (g/m2) were significantly higher (P<0.0005) in regular/elite athletes than in nonathletes (nonathlete/regular-athlete/elite-athlete; men RV-EDV 111/136/144, RV-wall mass 12/14/15, LV-EDV 101/123/129, LV-wall mass 48/62/69; women RV-EDV 96/115/118, RV-wall mass 10/13/14, LV-EDV 90/107/107, LV-wall mass 34/46/50). Male sex, body surface area, and training hours/week increase ventricular volume and wall mass. In elite athletes, short-axis RV diameter exceeded 50 mm in 49/16% (men/women), and LV diameter exceeded 60 mm in 55/16% (men/women). Interventricular septal-wall thickness was 13-15 mm in 5% regular and 15% elite male athletes.

Conclusions

Cardiac MRI reference values show increased ventricular volumes, diameters, wall mass, and wall thickness for endurance athletes compared with nonathletes. High training hours/week and male sex result in an increased overlap with standard thresholds for cardiomyopathy. To help prevent inconclusive reports, the 95th percentile reference values can be used as an alternative to standard upper limits used for the general population.

Baseline demographics young - men

NonathletesRegular athletesElite athletes
n568346
Age (years)26 ± 5.226 ± 6.426 ± 4.9
Height (cm)183 ± 7.1186 ± 7.3186 ± 7.3
Weight (kg)78 ± 8.780 ± 9.078 ± 10
Body surface area (m2)2.0 ± 0.12.0 ± 0.22.0 ± 0.2
Systolic BP (mmHg)128 ± 11133 ± 12126 ± 11**
Diastolic BP (mmHg)76 ± 9.474 ± 8.371 ± 8.2*
Mean heart rate (bpm)66 ± 1259 ± 9.7**58 ± 11**
Training (h/w)1.7 ± 1.312 ± 2.4***24 ± 5.6***,**
Training duration (years)4.9 ± 4.55.1 ± 4.77.5 ± 4.0*,*
Data are expressed as mean ± SD. BP, blood pressure; bpm, beats per minute; h/w, hours endurance excercise training per week. aP values for significant differences between nonathlete controls and regular endurance athletes. bP values for significant differences between nonathlete controls and elite endurance athletes are marked: *P <0.05; **P < 0.005; ***P < 0.0005; P values for significance in differences between regular and elite endurance athletes after the comma: *P < 0.05; **P <0.005; ***P < 0.0005.

Baseline demographics young - woman

NonathletesRegular athletesElite athletes
n586033
Age (years)26 ± 5.925 ± 5.325 ± 4.2
Height (cm)171 ± 5.6177 ± 13*177 ± 7.0*
Weight (kg)63 ± 7.766 ± 7.270 ± 8.8***
Body surface area (m2)1.7± 0.11.8± 0.1*1.9± 0.1***
Systolic BP (mmHg)121 ± 12121 ±12124 ± 13
Diastolic BP (mmHg)73 ± 8.070 ± 9.270 ± 6.7
Mean heart rate (bpm)67 ± 9.858 ± 9.9***57 ± 8.6***
Training (h/w)1.9 ± 1.213 ± 2.4***22 ± 3.5***,***
Training duration (years)4.4 ± 4.55.6 ± 4.48.8 ± 3.7***,***
Data are expressed as mean ± SD. BP, blood pressure; bpm, beats per minute; h/w, hours endurance excercise training per week. aP values for significant differences between nonathlete controls and regular endurance athletes. bP values for significant differences between nonathlete controls and elite endurance athletes are marked: *P <0.05; **P < 0.005; ***P < 0.0005; P values for significance in differences between regular and elite endurance athletes after the comma: *P < 0.05; **P <0.005; ***P < 0.0005.

Ventricular volumes and wall mass, systolic function - men

NonathletesRegular athletesElite athletes
AbsoluteAbsolute/BSAAbsoluteAbsolute/BSAAbsoluteAbsolute/BSA
Men568346
RV
EDV223 ± 40 (287)111 ± 18 (139)277 ± 36 (335)***136 ±16 (162)***291 ± 48 (406)***144 ± 20 (175)***,*
ESV108 ± 24 (153)54 ± 12 (72)135 ± 25 (182)***66 ± 12 (85)***148 ± 30 (210)***,*73 ± 13 (94)***,*
MassMass 23 ± 4.8 (32)12 ± 2.3 (15)29 ± 5.5 (41)***14 ± 2.7 (18)***30.0 ± 5.5 (43)***15 ± 2.3 (19)***
EF52 ± 4.7 (59)51 ±4.4 (59)50 ± 4.4 (58)*
LV
EDV201 ± 33 (257)101 ± 15 (125)250 ± 32 (305)***123 ± 13 (145)***261 ± 39 (332)***129 ± 17 (155)***
ESV87 ± 19 (125)43 ± 9.5 (59)108 ± 20 (140)***53 ± 9.0 (67)***117 ± 24 (166)***58 ± 11 (78)***,*
Mass95 ± 20 (122)48 ± 9.4 (59)125 ± 22 (171)***62 ± 11 (80)***139 ± 28 (205)***,** 69 ± 13 (91)***,**
EF57 ± 5.8 (67)57 ± 4.7 (65)55 ± 5.4 (64)
Data are expressed as mean mm± SD (95th percentile). BSA, body surface area; IVSmax, maximum interventricular septal-wall-thickness (mm); LVD, RVD, left and right ventricle end-diastolic diameter (mm). aP values for significant differences between nonathlete controls and regular endurance athletes. bP values for significant differences between nonathlete controls and elite endurance athletes are marked: *P < 0.05; **P < 0.005; ***P <0.0005; P values for significance in differences between regular and elite endurance athletes after the comma: *P < 0.05; **P < 0.005; ***P <0.0005.

Ventricular volumes and wall mass, systolic function - Woman

NonathletesRegular athletesElite athletes
AbsoluteAbsolute/BSAAbsoluteAbsolute/BSAAbsoluteAbsolute/BSA
Woman586033
RV
EDV166 ±23 (205) 96 ±12 (116) 209± 29 (257)*** 115 ±15 (140)*** 219 ± 35 (292)*** 118 ± 17 (145)***
ESV75 ± 13 (99) 43 ± 7.0 (55) 102 ± 17 (128)*** 57± 8.8 (71)*** 103 ±24 (144)*** 56± 13 (76)***
Mass18 ± 3.8 (26) 10 ± 2.2 (14) 23 ± 3.8 (30)*** 13 ± 2.0 (16)*** 25 ±4.5 (37)*** 14 ±2.7 (18)***
EF55 ± 4.8 (64) 51 ± 3.8 (57)*** 53 ±6.9 (67)
LV
EDV156 ±22 (197) 90 ± 11 (109)194± 27 (234)*** 107± 14 (128)*** 199± 31 (264)*** 107± 14 (131)***
ESV65 ± 13 (89) 37 ±6.8 (49)86± 15 (112)*** 48± 7.9 (59)*** 85 ±20 (127)***46 ±11 (61)***
Mass60 ±11 (79) 34 ±6.2 (43) 84± 17 (124)*** 46± 9.2 (64)***92 ±15 (117)*** 50± 7.6 (64)***
EF58 ± 5.3 (68) 55 ± 4.0 (62)* 58 ±6.6 (68)
Data are expressed as mean mm± SD (95th percentile). BSA, body surface area; IVSmax, maximum interventricular septal-wall-thickness (mm); LVD, RVD, left and right ventricle end-diastolic diameter (mm). aP values for significant differences between nonathlete controls and regular endurance athletes. bP values for significant differences between nonathlete controls and elite endurance athletes are marked: *P < 0.05; **P < 0.005; ***P <0.0005; P values for significance in differences between regular and elite endurance athletes after the comma: *P < 0.05; **P < 0.005; ***P <0.0005.

Short-axis ventricular diameters and interventricular septal-wall thickness

NonathletesRegular athletesElite athletes
AbsoluteAbsolute/BSAAbsoluteAbsolute/BSAAbsoluteAbsolute/BSA
Men568346
RVD45 ±5.9 (55) 23 ± 2.9 (28) 48 ±6.2 (59)* 23 ± 3.2 (29) 49 ±5.1 (58)** 24 ±2.9 (30)*
LVD56± 3.7 (63) 28 ± 2.0 (31) 59 ±3.9 (66)*** 29 ± 2.2 (32)* 60 ±4.1 (68)*** 30± 2.6 (34)***
IVSmax9.5 ±1.2 (12) 4.8± 0.6 (5.7) 11 ±1.4 (13)*** 5.2± 0.7 (6.4)*** 11 ± 1.4 (14)***,** 5.7± 0.7 (6.9)***,**
Woman586033
RVD39 ±4.6 (48) 23 ± 2.8 (28) 44± 5.1 (55)*** 25 ± 3.1 (31)** 43 ±5.8 (52)** 23 ± 3.7 (31)
LVD51 ± 3.4 (59)30± 2.2 (33) 55 ±3.7 (62)*** 30± 2.4 (34) 56± 3.7 (63)*** 30 ±2.5 (35)
IVSmax7.8± 1.0 (10) 4.5± 0.5 (5.3) 9.1± 1.1 (12)*** 5.1± 0.6 (6.3)*** 9.0 ±1.3 (12)*** 4.9± 0.7 (6.4)*
Data are expressed as mean mm± SD (95th percentile). BSA, body surface area; IVSmax, maximum interventricular septal-wall-thickness (mm); LVD, RVD, left and right ventricle end-diastolic diameter (mm). aP values for significant differences between nonathlete controls and regular endurance athletes. bP values for significant differences between nonathlete controls and elite endurance athletes are marked: *P < 0.05; **P < 0.005; ***P <0.0005; P values for significance in differences between regular and elite endurance athletes after the comma: *P < 0.05; **P < 0.005; ***P <0.0005.