Pediatric Cardiology Fellowship Standards for Training in Exercise Medicine and Curriculum Outline

Over the past 2 decades, fundamentals of exercise medicine, including clinical exercise testing, assessment and promotion of physical activity, exercise prescription, and supervised exercise training/rehabilitation programming have demonstrated considerable clinical value in the management of children and adolescents with congenital and acquired heart disease. Although the principles of exercise medicine have become an integral component in pediatric cardiology, there are no standardized training recommendations for exercise physiology during pediatric cardiology fellowship at this time. Thus, the Pediatric Cardiology Exercise Medicine Curriculum Committee (PCEMCC) was formed to establish core and advanced exercise physiology training recommendations for pediatric cardiology trainees. The PCEMCC includes a diverse group of pediatric cardiologists, exercise physiologists, and fellowship program directors. The expert consensus training recommendations are by no means a mandate and are summarized herein, including suggestions for achieving the minimum knowledge and training needed for general pediatric cardiology practice.

Persistent hyperdynamic cardiovascular state at rest and during exercise in children after successful repair of coarctation of the aorta

OBJECTIVES

The purposes of this study were to evaluate left ventricular performance and contractility at rest and during exercise to determine mechanisms and correlates for alterations in performance and blood pressure in pediatric patients after successful repair of coarctation of the aorta.

BACKGROUND

Blood pressure and left ventricular function are elevated in children despite successful repair. The mechanisms for these changes are not understood.

METHODS

Thirty asymptomatic pediatric patients with successful coarctation repair (mean age [+/- SD] 12.5 +/- 4 years) underwent echocardiographic determination of left ventricular mass, performance (shortening fraction), preload (indexed diastolic dimension), afterload (end-systolic wall stress), contractility (velocity of circumferential fiber shortening/wall stress relation) and Doppler gradient at rest and during exercise. Data were compared with those of 24 control subjects (mean age 21.0 +- 4 years). Because of the age discrepancy between groups, age-dependent echocardiographic data were indexed by body surface area.

RESULTS

The mean age at operation was 5 +/- 4 years, and the average follow-up period was 7.5 +/- 3 years. The average blood pressure gradient between upper and lower limbs was 4 mm Hg. Left ventricular mass was higher in the postoperative group than in the control group (1.58 vs. 1.31 g/ht2.7, p = 0.04), as were values at rest for performance (44% vs. 31%, p = 0.0001), preload (3.9 vs. 3.7 cm/body surface area0.5), indexes systolic blood pressure (1.05 vs. 0.91, p = 0.0001) and contractility (0.23 vs. -0.05 circumferences/s, p= 0.001). Afterload was lower at rest (36 vs. 52 g/cm2, p = 0.0004). These differences between groups persisted during and after exercise. Contractility underwent an exaggerated increase after exercise in the postoperative group.

CONCLUSIONS

Left ventricular performance in children after coarctation repair is higher at rest and during exercise than in control subjects as a result of higher preload and contractility and lower afterload. These changes may be due to associated hypertrophy. Persistent postoperative hypertension may be due to a hyperdynamic, hypercontractile state caused by residual gradients manifested only during exertion.

Echocardiographic determination of left ventricular preload, afterload, and contractility during and after exercise

Left ventricular (LV) performance increases during acute exercise, but the mechanisms for this increase are not known. To determine the feasibility of studying echocardiographic indexes of performance and its determinants (preload, afterload, and contractility) during exercise, and to examine changes in these indexes, we tested 24 normal male subjects (aged 21 +/- 5 years) by echocardiography--at rest; at 25%, 50%, 75%, and 100% maximal oxygen consumption; and immediately, 3 minutes, and 5 minutes after cycle ergometry. The LV performance (shortening fraction), preload (LV end-diastolic dimension), afterload (wall stress), contractility, heart rate, and peak systolic blood pressure were measured. Data could be obtained during 98% of the exercise studies. The LV performance, heart rate, blood pressure, and contractility increased significantly with increasing exercise, reaching peak levels at maximal exercise, and decreased toward resting levels in the post-exercise period. The LV afterload and preload decreased significantly with increasing exercise intensity, reaching nadir levels at maximal exercise, and increased toward resting levels in the post-exercise period. We conclude that echocardiographic measurement of LV performance and its determinants is feasible during exercise. Performance of the LV increases with increasing exercise intensity because of an associated increase in contractility and decrease in afterload. These data will serve as a basis for comparison with those from other patient populations.