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

Abstract

Background-The question of whether training-induced left ventricular hypertrophy in athletes is a physiological rather than a pathophysiological phenomenon remains unresolved. The purpose of the present study was to detect any abnormalities in cardiac function in hypertrophic hearts of elite cyclists and to examine the response of myocardial high-energy phosphate metabolism to high workloads induced by atropine-dobutamine stress. Methods and Results-We studied 21 elite cyclists and 12 healthy control subjects. Left ventricular mass, volume, and function were determined by cine MRI. Myocardial high-energy phosphates were examined by 31 P magnetic resonance spectroscopy. There were no significant differences between cyclists and control subjects for left ventricular ejection fraction (59Ϯ5% versus 61Ϯ4%), left ventricular cardiac index (3.4Ϯ0.4 versus 3.4Ϯ0.4 L ⅐ min Ϫ1 ⅐ m Ϫ2 ), peak early filling rate (562Ϯ93 versus 535Ϯ81 mL/s), peak atrial filling rate (315Ϯ93 versus 333Ϯ65 mL/s), ratio of early and atrial filling volumes (3.0Ϯ1.0 versus 2.6Ϯ0.6), mean acceleration gradient of early filling (5.2Ϯ1.4 versus 5.8Ϯ1.9 L/s 2 ), mean deceleration gradient of early filling(Ϫ3.1Ϯ0.9 versus Ϫ3.2Ϯ0.7 L/s

Effect of intramyocardial bone marrow cell injection on diastolic function in patients with chronic myocardial ischemia

“…In the present study, both MRI and TDI were used for the evaluation of diastolic function after intramyocardial bone marrow cell injection. MR phase contrast flow velocity mapping allows measurement of flow-velocity as well as flow-volumes across the mitral valve orifice, providing a new means of diastolic function assessment that may even be a more sensitive method than Doppler echocardiography (9,11,12). Flow velocity mapping revealed an increase in the E/A peak flow ratio at the three-month follow-up, which was mainly determined by an improvement in the E peak filling rate, whereas the A peak filling rate remained unchanged.…”

“…Flow curves were automatically analyzed following a manual indication of the start of early filling, peak early filling, peak atrial contribution to filling, and the end of filling as previously described (9). To assess intra-and interobserver variabilities, 20 randomly chosen MRI scans were reanalyzed by the initial observer (blinded to the initial results and with an interval of more than six months) and by a second observer (blinded to the results from the first observer).…”

Differences in the Bioenergetic Response of the Isolated Perfused Rat Heart to Selective β 1 - and β 2 -Adrenergic Receptor Stimulation

“…31 P NMR spectroscopy provides real-time measurements of the intracellular concentrations of phosphocreatine (PCr), ATP, and inorganic phosphate (P i ), as well as pH. Previous applications of this technique have been made to ␤-adrenergic stimulation in isolated [5][6][7][8] and in situ 9,10 rat hearts, isolated guinea pig hearts, 11 in situ rabbit hearts 12 and human hearts, 13,14 each demonstrating decreased PCr concentration, but without specifically addressing differences between ␤ 1 -and ␤ 2 -AR-mediated effects.…”

Beurteilung der linksventrikulären Funktionsparameter mit Cine-MRT und 3D kt-BLAST

“…[Pluim 1998, Mohiaddin 1995. Mittels dieser Untersuchungsverfahren lassen sich frühzeitig Durchblutungsstörungen erkennen, die regionale Myokardfunktion beurteilen,…”