Cardiac anatomy, function and metabolism in elite cyclists assessed by magnetic resonance imaging and spectroscopy

Abstract

We investigated whether left ventricular hypertrophy in elite cyclists is associated with functional changes or abnormal energy metabolism. Left ventricular hypertrophy is a powerful risk factor for sudden cardiac death with different prognostic significance among the various geometric forms. Cyclists may have a combination of mixed eccentric and concentric hypertrophy. Magnetic resonance imaging was used to define left ventricular mass, geometry and function. Thirteen highly trained male cyclists and 12 healthy controls were investigated. Proton-decoupled phosphorus-31 cardiac spectroscopy was performed to assess parameters of myocardial high-energy phosphate metabolism. Left ventricular mass and end-diastolic volumes normalized for body surface area were significantly higher in cyclists (124.1 +/- 9.4 g.m-2 and 106.2 +/- 11.4 ml.m-2, respectively) than in controls (85.9 +/- 9.3 g.m-2 and 79.1 +/- 11.6 ml.m-2, respectively), (both P < 0.0001). The left ventricular mass to end-diastolic volume ratio, as a parameter of left ventricular geometry, was not significantly increased in cyclists compared to controls. Resting left ventricular ejection fraction, cardiac index, and systolic wall stress in cyclists did not differ significantly from those of controls. The phosphocreatine to adenosine triphosphate ratio was not significantly different between cyclists and controls (2.2 +/- 0.34 vs 2.2 +/- 0.17, ns). Cyclists show prominent left ventricular hypertrophy with normal geometry. The finding that the hypertrophic hearts of the cyclists had normal left ventricular function and a normal phosphocreatine to adenosine triphosphate ratio suggests that sport-induced left ventricular hypertrophy is a physiological adaptation rather than a pathophysiological response.

Functional and Metabolic Evaluation of the Athlete’s Heart By Magnetic Resonance Imaging and Dobutamine Stress Magnetic Resonance Spectroscopy

“…In addition, we found a similar decrease in myocardial PCr/ATP ratio during high workloads caused by atropine-dobutamine stress in cyclists and sedentary control subjects. This study extends our previous findings in cyclists, 17 in whom we demonstrated a Figure 2. Representative cardiac 31 P magnetic resonance spectroscopy spectra of a cyclist and a control subject at rest and during atropine-dobutamine stress.…”

“…14 -16 A recent study from our institution demonstrated normal systolic function parameters and a normal high-energy phosphate metabolism in elite cyclists at rest. 17 In that study, however, we did not investigate diastolic function or high-energy phosphate metabolism during stress. Because abnormalities of diastolic filling may precede abnormalities of systolic function in the early stages of disease, we considered it important to evaluate diastolic function in cyclists as well.…”

Hypertension control is needed in elderly marathon runners!

“…This type of LVH is considered physiological [5][6][7][8][9][10]. Conditions like hypertensive heart disease lead to pathological LVH [11][12][13][14][15], as it is often associated with perivascular and interstitial fibrosis of left ventricular myocardium [16], diastolic heart failure [17,18], arrhythmias [19,20] and mortality [21].Previous studies from our institution have already addressed the issue of physiological versus pathological LVH [5,22,23]. First of all we studied the accuracy of M-mode echocardiography and two different twodimensional echocardiographic approaches in the assessment of left ventricular mass and volumes in endurance-trained and strength-trained athletes, using cardiovascular magnetic resonance (CMR) imaging as reference standard [23].…”

“…Previous studies from our institution have already addressed the issue of physiological versus pathological LVH [5,22,23]. First of all we studied the accuracy of M-mode echocardiography and two different twodimensional echocardiographic approaches in the assessment of left ventricular mass and volumes in endurance-trained and strength-trained athletes, using cardiovascular magnetic resonance (CMR) imaging as reference standard [23].…”

“…First of all we studied the accuracy of M-mode echocardiography and two different twodimensional echocardiographic approaches in the assessment of left ventricular mass and volumes in endurance-trained and strength-trained athletes, using cardiovascular magnetic resonance (CMR) imaging as reference standard [23]. It was shown that in general practice the two-dimensional echocardiographic approach was the most accurate estimator of left ventricular mass and volumes in both controls and athletes.…”