The Munich Triathlon Heart Study: ventricular function, myocardial velocities, and two-dimensional strain in healthy children before and after endurance stress.

Intense exercise has been shown to have negative effects on systolic and diastolic ventricular function in adults. Very little is known about the normal reaction of the growing heart to endurance stress. For this study, 26 healthy children (18 males) with a mean age of 12.61 years (range, 7.92-16.42 years) took part in an age-adapted triathlon circuit. The athletes were investigated by two-dimensional (2D) echocardiographic/speckle tracking, M-mode, pulse-wave Doppler, color Doppler, and color-coded tissue Doppler at 2-4 weeks before and immediately after the race. After the competition, cardiac output increased, mediated by an increase in heart rate and not by an elevated preload, according the Frank-Starling mechanism. Two-dimensional speckle tracking showed a reduced longitudinal strain in the right and left ventricles and additionally reduced circumferential strain in the left ventricle. The late diastolic inflow velocities were increased in both ventricles, indicating reduced diastolic function due to an impairment of myocardial relaxation. Immediately after endurance exercise, systolic and diastolic functions were attenuated in children and adolescents. In contrast to adult studies, this study could show a heart rate-mediated increase in cardiac output. The sequelae of these alterations are unclear, and the growing heart especially may be more susceptible to myocardial damage caused by intense endurance stress.

Durability of bioprostheses for the tricuspid valve in patients with congenital heart disease.

OBJECTIVES: Only little data exist on the durability of bioprostheses in the tricuspid position in patients with congenital heart disease (CHD). The aim of the study was to determine the reoperation rate and the valve function after primary implantation. METHODS: Between 1990 and 2013, 51 patients with CHD underwent tricuspid valve (TV) replacement with a bioprosthesis. The median age at operation was 32 years (range: 8-69). The underlying morphology was Ebstein's anomaly in 62% of the patients. Implanted valves included 38 pericardial and 13 porcine valves. All available echocardiographic examinations (n = 714) and clinical data were retrospectively reviewed. Dysfunction was defined as an at least moderate regurgitation or a mean diastolic gradient ≥9 mmHg. Freedom from death, reoperation and prosthetic valve dysfunction was estimated using the Kaplan-Meier method. RESULTS: The 30-day mortality rate was 9%. The estimated survival rate was 86% at one and 80% at ten years. The freedom from reoperation at 1, 5 and 10 years was 100, 86 and 81%, and that from prosthesis dysfunction detected by echocardiography at 1, 5 and 10 years was 89, 66 and 58%, respectively. The main reason for dysfunction was insufficiency (89%). Valve implantation at an age below 16 years was associated with earlier reoperation and dysfunction (the 5-year freedom rate from reoperation/dysfunction was 70%/30% compared with 89%/78% in the rest of the patients, P = 0.016/0.0009). CONCLUSIONS: Serial echocardiography shows a high rate of dysfunction of TV bioprosthesis in patients with CHD, which already occurred a few years after implantation. In patients below 16 years of age, most prostheses are dysfunctional within 5 years.

Creating an arc-shaped aorta: use of the subclavian artery for interrupted aortic arch repair.

BACKGROUND: With interrupted aortic arch (IAA), a direct anastomosis may produce an angular-shaped aortic arch instead of the normal arc-shaped aorta, when the discontinuity is considerably long. That may lead to aortic stenosis and to compression of the pulmonary artery or the main bronchus. If a tube graft is used, reoperation for graft exchange is inevitable. We demonstrate the results of using the subclavian artery for creating an arc-shaped aorta in IAA repair. METHODS: Between February 2006 and October 2012, 23 patients underwent IAA repair using the subclavian artery. The subclavian artery was closed distally, divided, and longitudinally incised from the transected end to the aorta. This flap was used to bridge the gap of the IAA, by forming the posterior wall of a new aortic segment. The arch was completed using glutaraldehyde-fixed autologous pericardium (52%) or homograft (48%). RESULTS: Median follow-up time was 4.8 years (range, 1.3 to 6.9). There were no early deaths and 1 late death. On postoperative angiographic imaging, the aorta takes an arc-shaped course in all cases. Aortic arch stenosis developed in 7 patients (30%). Four patients were treated interventionally, and 3 surgically. During follow-up, there was no compression of the pulmonary artery or the main bronchus. CONCLUSIONS: By using the subclavian artery, an arc-shaped aorta can be accomplished without the use of tube grafts. With this technique, compression of the pulmonary artery or the main bronchus can be avoided. This technique is recommended if a direct anastomosis might be not applicable to bridge a long interruption.