Ricard Serra-Grima

Transient alterations in cardiac performance after a six-hour race☆

Ten long distance runners were enrolled in a 6-hour competitive race. Immediately after the race technetium-99m-albumin gated blood pool scans were performed and indium-111 antimyosin was injected. Forty-eight hours later antimyosin scans were obtained and control gated blood pool scans were performed. Left ventricular ejection fraction was higher after the race (65 +/- 5 vs 60 +/- 7%, p less than 0.01) due to a decrease in end-systolic counts. Right ventricular ejection fraction was lower after the race (42 +/- 7 vs 54 +/- 12%, p = 0.03) due to an increase in both end-diastolic and end-systolic counts. A longer systolic period was observed after the race (53 +/- 5% of the RR interval vs 39 +/- 3%, p = 0.005). No significant differences were observed in peak filling or peak emptying rates after the race. An increase in pulmonary blood volume (116% of control) was observed after the race. Antimyosin scans were normal in 7 athletes and minimal antimyosin myocardial uptake was seen in 3. Transient alterations in biventricular performance present after the race correspond to function adaptation to strenuous exercise and are not due to irreversible myocyte damage.

Influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation in ischaemic heart disease

Abstract.Exercise rehabilitation improves the clinical status in ischaemic heart disease. The purpose of this study was to assess the influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation. Sixteen patients with ischaemic heart disease and previous myocardial infarction were investigated by means of exercise/rest tetrofosmin and metaiodobenzylguanidine (MIBG) exercise/rest single-photon emission tomography (SPET) studies, before and 6 months after starting an exercise rehabilitation programme. Tomograms were divided into 15 segments, and these were grouped into five myocardial anatomical regions. Regional uptake of both tracerswas quantified and expressed as a percentage of maximumpeak activity. The percentage ≤55% was chosen to evaluate defect size, and the results were expressed as a percentage of left ventricular mass. Areas with perfused and denervated myocardium and areas with ischaemic myocardium were calculated. In addition, regions with <75% of peak activity in the exercise perfusion study at baseline were divided into two groups according to whether there was an increase in peak activity of >10% (representing reversible regional defects) or an increase of <10% (representing fixed regional defects) in the rest study. These percentages were compared with the percentages obtained in the innervation study, and with the percentages obtained in exercise/rest perfusion and innervation studies performed 6 months after starting rehabilitation. Myocardial perfusion defects were significantly smaller than myocardial innervation defects before and 6 months after starting exercise rehabilitation. The area of ischaemia 6 months after starting exercise rehabilitation was significantly smaller than that before rehabilitation (0.31%± 1.4% vs 1.4%±1.6%, P<0.01). The size of innervation defects and the area of perfused and denervated myocardium did not show significant differences between the two studies performed before and 6 months after starting exercise rehabilitation. In reversible regional defects the percentage of peak activity was significantly increased 6 months after starting exercise rehabilitation in exercise and rest studies (P<0.001), while in fixed regional defects it was significantly increased only in exercise studies (P<0.001). There was no significant change in the regional MIBG percentages. We conclude that in ischaemic heart disease, exercise rehabilitation over a period of 6 months improves myocardial perfusion, but does not cause changes in sympathetic myocardial innervation.

Effects of an exercise programme on functional capacity, body composition and risk of falls in patients with cirrhosis: a randomized clinical trial

Patients with cirrhosis often have functional limitations, decreased muscle mass, and a high risk of falls. These variables could improve with exercise. The aim was to study the effects of moderate exercise on functional capacity, body composition and risk of falls in patients with cirrhosis. Twenty-three cirrhotic patients were randomized to an exercise programme (n = 14) or to a relaxation programme (n = 9). Both programmes consisted of a one-hour session 3 days a week for 12 weeks. At the beginning and end of the study, we measured functional capacity using the cardiopulmonary exercise test, evaluated body composition using anthropometry and dual energy X-ray absorptiometry, and estimated risk of falls using the Timed Up&Go test. In the exercise group, cardiopulmonary exercise test showed an increase in total effort time (p<0.001) and ventilatory anaerobic threshold time (p = 0.009). Upper thigh circumference increased and mid-arm and mid-thigh skinfold thickness decreased. Dual energy X-ray absorptiometry showed a decrease in fat body mass (-0.94 kg, 95%CI -0.48 to -1.41, p = 0.003) and an increase in lean body mass (1.05 kg, 95%CI 0.27 to 1.82, p = 0.01), lean appendicular mass (0.38 kg, 95%CI 0.06 to 0.69, p = 0.03) and lean leg mass (0.34 kg, 95%CI 0.10 to 0.57, p = 0.02). The Timed Up&Go test decreased at the end of the study compared to baseline (p = 0.02). No changes were observed in the relaxation group. We conclude that a moderate exercise programme in patients with cirrhosis improves functional capacity, increases muscle mass, and decreases body fat and the Timed Up&Go time. Trial Registration: ClinicalTrials.gov NCT01447537

Influence of prolonged exercise on myocardial distribution of 123I-MIBG in long-distance runners

BackgroundA study was conducted to determine if prolonged exercise could provoke sympathetic neuronal alteration in an athlete’s heart through assessment of myocardial distribution of 123I-metaiodobenzylguanidine (MIBG) in nine ultramarathon runners at baseline and after a 4-hour race.Methods and resultsAfter injection of 370 MBq of 123I-MIBG, the athletes ran for 4 hours, covering 45±8 km. Planar and single-photon emission computed tomography (SPECT) images of the thorax were acquired at the end of the race. Two weeks later, studies at baseline were performed. A heart: mediastinum ratio (HMR) was calculated to quantify MIBG uptake. Basal MIBG studies showed normal myocardial tracer uptake, on both planar and SPECT images, and the HMR was 1.84±0.16. After the 4-hour race, MIBG studies showed decreased myocardial uptake in all athletes, and the HMR was 1.70±0.18 (p<0.005). A positive correlation between the percentage of decrease of HMR after the race and the distance covered was observed (r=.910, p<0.001).ConclusionsMyocardial MIBG activity is decreased by prolonged exercise in long-distance runners. The degree of reduction of myocardial MIBG activity is related to the distance covered. Prolonged exercise, as sustained sympathetic stimulus, may alter myocardial distribution of MIBG.

Concordance between rest MIBG and exercise tetrofosmin defects: possible use of rest MIBG imaging as a marker of reversible ischaemia

Abstract. Perfusion imaging combined with pharmacological stress is the study of choice in patients with ischaemic heart disease who are incapable of exercising. Some medical conditions, however, can preclude the use of pharmacological stress. In these particular situations, availability of a diagnostic test which allows for the assessment of ischaemic territory at rest would be desirable. With the purpose of providing a marker of reversible ischaemia, we evaluated myocardial iodine-123 metaiodobenzylguanidine (MIBG) uptake in regions with fixed and reversible defects defined by exercise/rest perfusion study. Fifty-four male patients with ischaemic heart disease and previous myocardial infarction were studied by means of exercise/rest tetrofosmin and MIBG single-photon emission tomography (SPET). Regional tracer uptake was quantified and expressed as a percentage of maximum peak activity. Areas with denervated but perfused myocardium and areas with ischaemic myocardium were calculated. Regions with<75% of peak activity in the exercise perfusion study were divided into two groups according to whether the increase in peak activity in the respective rest study was >10% (reversible regional defect) or <10% (fixed regional defect). These percentages were compared with the percentages of the innervation study. The area of the innervation defect was significantly larger when the perfusion defect was reversible than when it was fixed. In regions with reversible perfusion defects, the size of the area of denervated but perfused myocardium was similar to the size of the area of ischaemic myocardium. In regions with reversible defects, the percentage of myocardial MIBG uptake was not significantly different from the percentage of tetrofosmin uptake at exercise, while it was significantly lower than the percentage of tetrofosmin uptake at rest. In regions with fixed defects, the percentage of myocardial MIBG uptake was significantly lower than the percentage of tetrofosmin uptake at exercise and at rest. In patients who developed angina during exercise test, the area of denervated but perfused myocardium was significantly larger than in patients without angina (4.1±2.4 vs 3.4±2.5, P=0.02). The same trend was observed with regard to the size of the innervation defect (8.6±2.4 vs 5.7±2.2, P=0.02). It is concluded that when the use of pharmacological stress is not possible in patients incapable of exercising, rest studies with MIBG combined with rest myocardial perfusion studies may be useful as a marker of reversible ischaemia.

Prueba de esfuerzo con función cardiopulmonar en niños operados de cardiopatía congénita. Recomendaciones de ejercicio físico en el ámbito escolar

INTRODUCTION AND OBJECTIVES To analyze and discover if stress testing with exhaled gases in children who have had congenital heart surgery is useful so we could make physical exercise recommendations according to heart disease, type of surgery performed, present hemodynamic state and level of exercise practiced. METHODS Prospective study of 108 children, who performed stress testing with exhaled gases, electrocardiogram monitoring and blood pressure. A questionnaire was used to obtain variables concerning heart disease, surgery, present functional condition and level of exercise practiced. Exercise recommendations were given after stress testing, and after a year 35 patients answered a questionnaire. RESULTS There were significant differences between lesion severity and heart rate at rest and during effort, systolic pressure at rest and during effort, oxygen uptake, oxygen pulse, carbon dioxide production and test duration. A relationship was observed between level of weekly exercise and greater oxygen uptake and test duration, but this was not observed with the underlying heart disease. We observed that best performance occurred with fast repairing for 59 children with cyanotic heart disease. Increased exercise level was recommended for 48 children. CONCLUSIONS The cardiopulmonary function study allows us to examine the physical performance of children who have had congenital heart surgery and provides us with important data so that we can recommend better physical exercise planning.

Myocardial remodelling and tissue characterisation by cardiovascular magnetic resonance (CMR) in endurance athletes

There is still some controversy about the benignity of structural changes observed in athlete’s heart, especially regarding the observation of increased biomarkers and the presence of myocardial fibrosis (MF). Aim Our purpose was to evaluate by cardiovascular magnetic resonance (CMR) the presence of diffuse as well as focal MF in a series of high-performance veteran endurance athletes. Methods Thirty-four veteran healthy male endurance athletes, still being in regular training, with more than 10 years of training underwent a CMR. A cardiopulmonary exercise test was also performed to assess their maximal physical performance. The control group consisted in 12 non-trained normal individuals. Results We found an increase in both, right and left ventricular (LV) volumes in the athlete’s group when compared with controls. There was no increase in indexed LV myocardial mass despite of a significantly increased maximal myocardial wall thickness in comparison to controls. Native T1 values and extracellular volume (ECV) were normal in all cases. We did not find differences in native T1 values and ECV between both groups. In three athletes (9%), non-ischaemic late gadolinium enhancement (LGE) was observed. We did not find a correlation between total training volume and presence of LGE or with the ECV value. Conclusions Our results show that the majority of veteran endurance athletes present with myocardial remodelling without MF as a physiological adaptive phenomenon. In the only three athletes with focal MF, the LGE pattern observed suggests an intercurrent event not related with the remodelling phenomenon.

Gammagrafía miocárdica con 123I-MIBG en el síndrome de sobreentrenamiento

Presentamos el caso de un atleta de 21 años, sin antecedentes patológicos ni familiares de interés, que realiza un entrenamiento regular e intenso y refiere decaimiento, disminución de rendimiento (físico y psíquico) y sensación de mareo. En la exploración destaca una bradicardia sinusal < 40 lat/min, por lo que se realizaron una ecocardiografía (función ventricular izquierda normal), una prueba de esfuerzo (incremento normal de la presión arterial) y analítica (urea, ferritina sérica y enzimas hepáticas dentro de la normalidad). Se diagnosticó un síndrome de sobreentrenamiento y se indicó reposo. Se realizaron 2 gammagrafías con I-MIBG, una al diagnóstico y otra a las 10 semanas de reposo, se administraron 370 Mbq de I-MIBG por vía intravenosa y se adquirieron imágenes planares anteriores de tórax a las 4 h. Se cuantificó la captación de I-MIBG mediante el índice corazón/mediastino (ICM), que en el momento del diagnóstico estaba ligeramente disminuido (ICM, 1,71; normal, > 1,8) (fig. 1) y se normalizó después del reposo (ICM, 2,12) (fig. 2). El síndrome de sobreentrenamiento se define como un estado de fatiga prolongada y de bajo rendimiento físico secundario a un entrenamiento intenso con períodos inadecuados de reposo. Su consecuencia es un fallo de adaptación del sistema nervioso autónomo que da lugar a una disminución de la liberación pituitaria de ACTH y de la respuesta del cortisol, lo que pone de manifiesto una disminución de la actividad simpática intrínseca y de la sensibilidad a las catecolaminas. El diagnóstico definitivo es difícil de realizar debido a la variedad de síntomas y signos descritos. El primer signo que se presenta es la disminución del rendimiento asociado con sensación de fatiga física y psíquica, que generalmente se acompaña de una competición o un entrenamiento intenso recientes, lesiones musculares-tendinosas inexplicables, aumento de la irritabilidad, apatía, alteraciones del sueño, pérdida de peso, cambios de apetito, etc. En la exploración física se puede observar disminución de la frecuencia cardiaca y de la presión arterial. La determinación de diferentes enzimas y hormonas durante el entrenamiento físico puede ser útil para el diagnóstico y la prevención del sobreentrenamiento, y su único tratamiento es el reposo durante 6-12 semanas. En el caso que se presenta se diagnosticó sobreentrenamiento debido a la disminución de rendimiento físico y psíquico; el único signo observado fue la bradicardia sinusal, con todas las exploraciones complementarias normales. Recientemente se ha publicado un metaanálisis donde se muestra un efecto significativo del entrenamiento físico sobre el intervalo RR en reposo en individuos sanos, donde la bradicardia sinusal es debida a un incremento del tono vagal. La I-MIBG es un análogo de la guanetidina, de estructura similar a la noradrenalina, que actúa como un falso neurotransmisor y es captada activamente por la neurona presináptica. Su captación cardiaca se correlaciona con el contenido de noradrenalina y, por lo tanto, con la presencia de tejido simpático miocárdico. Estudios previos muestran una disminución de la captación miocárdica global con disminución del ICM en atletas, relacionado con el ejercicio físico y debido a un aumento del tono vagal. Estorch et al describieron una disminución de la captación de I-MIBG en corredores de maratón después de realizar ejercicio prolongado que se normalizó en reposo. En el caso descrito, la captación miocárdica estaba disminuida durante el cuadro clínico y volvió a ser normal después del reposo, lo que traduce una recuperación del sistema simpático. Se concluye que la gammagrafía cardiaca con I-MIBG puede ser un método útil para el diagnóstico y el control del síndrome de sobreentrenamiento del deportista.