Hemodynamic status in repaired tetralogy of Fallot assessed by Doppler echocardiography and cardiac catheterization. Comparisons with healthy subjects and elucidation of factors associated with cardiorespiratory function

Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating pathophysiology and for pulmonary valve replacement decision support

Surgical management of tetralogy of Fallot (TOF) results in anatomic and functional abnormalities in the majority of patients. Although right ventricular volume load due to severe pulmonary regurgitation can be tolerated for many years, there is now evidence that the compensatory mechanisms of the right ventricular myocardium ultimately fail and that if the volume load is not eliminated or reduced by pulmonary valve replacement the dysfunction might be irreversible. Cardiovascular magnetic resonance (CMR) has evolved during the last 2 decades as the reference standard imaging modality to assess the anatomic and functional sequelae in patients with repaired TOF. This article reviews the pathophysiology of chronic right ventricular volume load after TOF repair and the risks and benefits of pulmonary valve replacement. The CMR techniques used to comprehensively evaluate the patient with repaired TOF are reviewed and the role of CMR in supporting clinical decisions regarding pulmonary valve replacement is discussed.

Tetralogy of Fallot: postoperative delayed recovery of left ventricular stroke volume after physical exercise assessment with fast MR imaging

In six asymptomatic patients with corrected tetralogy of Fallot and nine healthy control subjects, the authors assessed left ventricular (LV) function during recovery from supine bicycle exercise by performing fast magnetic resonance (MR) flow mapping in the ascending aorta. Abnormal recovery of LV function after exercise was observed in the patients. MR flow mapping allows assessment of cardiac recovery after exercise.

Imaging of recurrent ventricular septal defect and supravalvular pulmonary stenosis eight years after assumed total surgical repair of tetralogy of Fallot

A 42-year-old man underwent assumed total surgical repair of an acyanotic tetralogy of Fallot: a perimembranous ventricular septal defect (VSD) was closed with a dacron patch and myectomy of the infundibulum of the right ventricular outflow tract was performed. Reexamination eight years later revealed a large recurrent VSD and by surprise a narrow supravalvular ridge above rudimentary pulmonary cusps in the pulmonary trunk, leading to a pressure drop of 70 mmHg across the supravalvular stenosis. The latter finding was not recognized during the operation eight years before. The diagnosis could noninvasively be established by means of magnetic resonance imaging. During revision surgery the VSD was closed and an aortic homograft was inserted as conduit between the right ventricle and the pulmonary artery.

Variability of digitized left ventricular M-mode echocardiography: a study in healthy subjects and patients with repaired tetralogy of Fallot

To assess possible factors affecting the variability of digitized left ventricular M-mode echocardiograms, the influence of respiration and the variability due to different beats and observers were analysed in 11 healthy subjects and 11 patients with repaired tetralogy of Fallot. Left ventricular end-diastolic dimension (LVEDD) decreased from end-expiration to end-inspiration in the healthy subjects, but not in the patients. The maximal rate of dimension change decreased in both healthy subjects and patients from end-expiration to end-inspiration. The beat-to-beat variability assessed by the coefficient of variation (CV,%) between measurements of one cardiac cycle was twice the CV for three cycles, whereas the CV for three and five cardiac cycles was not different. The CV for intraobserver variability was less than 5.0% for dimensions and less than 13.0% for the rates of dimension change, whereas the interobserver variability had CV of 17.1% for rates of dimension changes. The influence of respiration and different observers on the variability of LV end-systolic dimension and shortening fraction was larger in the patients than in the healthy subjects. Thus, to obtain optimal technique for analysis of digitized LV M-mode echocardiograms in serial patient studies, the number of observers should be kept at a minimum and at least 3 beats at end-expiration should be used.