Relation between cardiac dimensions and peak oxygen uptake

Abstract

Background: Long term endurance training is known to increase peak oxygen uptake (VO2peak) and induce morphological changes of the heart such as increased left ventricular mass (LVM). However, the relationship between and the total heart volume (THV), considering both the left and right ventricular dimensions in both males and females, is not completely described. Therefore, the aim of this study was to test the hypothesis that THV is an independent predictor of VO2peak and to determine if the left and right ventricles enlarge in the same order of magnitude in males and females with a presumed wide range of THV.

Methods and results: The study population consisted of 131 subjects of whom 71 were athletes (30 female) and 60 healthy controls (20 female). All subjects underwent cardiovascular MR and maximal incremental exercise test. Total heart volume, LVM and left- and right ventricular end-diastolic volumes (LVEDV, RVEDV) were calculated from short-axis images. was significantly correlated to THV, LVM, LVEDV and RVEDV in both males and females. Multivariable analysis showed that THV was a strong, independent predictor of (R2 = 0.74, p < 0.001). As LVEDV increased, RVEDV increased in the same order of magnitude in both males and females (R2 = 0.87, p < 0.001).

Conclusion: Total heart volume is a strong, independent predictor of maximal work capacity for both males and females. Long term endurance training is associated with a physiologically enlarged heart with a balance between the left and right ventricular dimensions in both genders.

Figure 1

Delineation of the pericardium enabling determination of the total heart volume from short-axis images. The base is found in the upper left corner and apex in the lower right corner. The white line indicates the pericardium. The right atrium, left atrium, right ventricle and left ventricle are indicated. Abbreviations: RA = right atrium, LA = left atrium, RV = Right ventricle, LV = left ventricle.

Figure 2

The relationship between total heart volume (THV) and peak oxygen uptake (). The upper panel shows the relationship between absolute THV and for A) all subjects, B) males and C) females. The lower panel shows the relationship between THV normalized for body surface area (BSA) and for D) all subjects, E) males and F) females. For both males and females, was significantly correlated to THV and to THV/BSA. Abbreviations: BSA = body surface area, THV = total heart volume, = peak oxygen uptake

Figure 3

The relationship between the left ventricular end-diastolic volume (LVEDV) and right ventricular end-diastolic volume (RVEDV) for: A) all subjects, B) males and C) females. The solid line is the regression line and the dashed line is the line of identity. There is a balanced enlargement of the left and right ventricle with increased amount of endurance training. Abbreviations: LVEDV = left ventricular end-diastolic volume, RVEDV = right ventricular end-diastolic volume.

Figure 4

Long axis images of the heart in a female control, male control, female triathlete and male triathlete. This figure illustrates the increase in cardiac dimensions with endurance training. Note that the female triathlete (height 1.80 m, weight 70 kg) has a larger heart than the male control subject (1.81 m, 80 kg).

Figure 5

Comparison of cardiac dimensions between males and females of the same sport: A) total heart volume normalized for body surface area (THV/BSA), B) left ventricular mass normalized for total heart volume (LVM/THV). Error bars denotes standard error of the mean. All male subject groups had a significantly higher THV/BSA and LVM/THV when compared to females, except for THV/BSA in triathletes. Abbreviations: C = control subjects, H = handball players, LVM = left ventricular mass, S = soccer players, T = triathletes, THV = total heart volume