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.

Comparison of the cardiac output and stroke volume response to upright exercise in children with valvular and subvalvular aortic stenosis.

Cardiac output and stroke volume were evaluated in 17 children (mean age 11.5 +/- 3 years) with discrete, membranous subvalvular (Group I, n = 7) and valvular (Group II, n = 10) aortic stenosis during submaximal and maximal (greater than 75% predicted maximal oxygen consumption) upright cycle ergometry. Patients with valvular aortic stenosis were further subdivided on the basis of their aortic valve gradient at rest determined by cardiac catheterization (Group IIA, gradient less than 40 mm Hg; Group IIB, gradient greater than or equal to 40 mm Hg). These patients were matched with 17 control subjects on the basis of age, sex, height and intensity of exercise during maximal exertion. Cardiac and stroke indexes were determined by the acetylene rebreathing method at each exercise level. Stroke volume index in Group I was significantly greater at rest when compared with that in control subjects (69 +/- 13 versus 53 +/- 11 ml/m2, alpha = 0.01, p less than 0.05) and that in patients in Group II (69 +/- 13 versus 47 +/- 12 ml/m2, alpha = 0.01, p less than 0.05). Patients with subvalvular aortic stenosis were unable to increase their stroke volume index from rest to submaximal exercise and also decreased their stroke volume index at maximal exercise levels. In contrast, patients with mild valvular aortic stenosis (Group IIA) displayed a normal exercise response. Patients with severe valvular aortic stenosis (Group IIB) had a blunted stroke volume response at rest and at each level of exercise, as well as signs of myocardial ischemia (ST segment depression) during maximal exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

A controlled study of type A behavior and psychophysiologic responses to stress in anorexia nervosa.

Adolescents and young adults meeting DSM-III criteria for anorexia nervosa (n = 13) and atypical eating disorders (n = 7) were compared with weight-recovered anorectics (n = 6) and normal weight controls (n = 11) using a type-A structured interview and a computerized stress procedure. Heart rate, blood pressure, and electrocardiographic changes were monitored. Anorexia nervosa subjects demonstrated significantly more type-A characteristics than controls. The emaciated and weight-recovered anorectics had elevated hostility scores on the type-A interview, which has been shown in recent studies of type-A behavior to be a risk factor for cardiovascular disease. This pilot study is the first to demonstrate a significant relationship between anorexia and the type-A behavioral pattern. Also the anorectic subjects showed significantly more cardiovascular reactivity than controls as measured by failure of stressed anorectic subjects to lower their systolic blood pressure to baseline levels as controls did. These results support the importance of monitoring stress reactions and personality traits as well as traditional biological measures.

Cardiac performance in children with pectus excavatum.

Fourteen children with pectus excavatum and 14 normal control patients underwent graded exercise testing using a cycle ergometer and the James protocol. All the subjects were preoperative. The children were exercised to exhaustion during the test. The pectus and control groups were broken down into subgroups consisting of subjects less than or equal to 10 years of age and subjects greater than or equal to 11 years of age (pectus and controls less than or equal to 10 years old, PI and CI, respectively; pectus and controls greater than or equal to 11 years old, PII and CII, respectively). Maximal workload, oxygen consumption, cardiac output, and stroke volume were not significantly different when comparing the total groups or when each of the respective subgroups were compared. However, maximal diastolic BP was significantly elevated when the entire pectus and control groups were compared. When the subgroups were compared, maximal diastolic BP was elevated only in the older pectus patients (PII) and remained so until five minutes after exercise. Additionally, left ventricular systolic time intervals were measured immediately after exercise in all the children. The ratio of preejection period to left ventricular ejection time (P/L) was significantly shortened in the total pectus group. When the subgroups were compared, the P/L ratio was significantly decreased only in the older patients. Also, the preejection period (PEP) was significantly shortened in the older pectus patients. It appears that children with pectus excavatum have a normal exercise tolerance and oxygen transport. However, older pectus children develop an increased diastolic BP and a shortened P/L and PEP in response to exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Cases from the aerospace medicine residents' teaching file. Case #45. An aviator with a pigmented skin lesion.

The initial presentation and diagnosis of an aviator with a pigmented skin lesion. The epidemiology of the skin cancer epidemic, including melanoma is discussed. Prognostic implications of melanoma and the U.S. Air Force experience with melanoma in aircrew are also depicted.

Maximal exercise in children with aortic regurgitation: an adjunct to noninvasive assessment of disease severity.

Twenty-five asymptomatic children with chronic aortic regurgitation were evaluated by graded bicycle exercise testing and standard resting M-mode echocardiogram. These results were compared to those of 35 normal controls matched for age and body surface area. Twenty-one patients underwent cardiac catheterization to rule out associated lesions. Patients fell into two groups based upon the left ventricular end-diastolic volume per body surface area (LVEDVI): group I (n = 10) had LVEDVI less than or equal to 2 SD from the mean of normal; group II (n = 15) had LVEDVI greater than or equal to 4 SD from the mean of normal. All had normal shortening fraction and velocity of circumferential fiber shortening. At maximal exercise, patients in group I were found to have no significant differences from normals in maximal workload, total work, percent maximal oxygen consumption, heart rate, blood pressure, or ST segment depression. However, patients in group II had blunted mean maximal exercise heart rate (p less than 0.001), systolic hypertension (p less than 0.05), and increased frequency and maximal amplitude of ST depression (p less than 0.01, p less than 0.001, respectively) compared to normal controls. Within group II the mean maximal amplitude of ST depression was significantly related to increasing LVEDVI (r = 0.53, p less than 0.05). The mean maximal exercise heart rate, systolic blood pressure, and maximal amplitude of ST segment depression were significantly related to LVEDVI for patient groups and normal controls together (r = -0.384, p less than 0.01; r = 0.28, p less than 0.05; r = 0.70, p less than 0.001, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

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.