Syncope Best Practices: A Syncope Clinical Practice Guideline to Improve Quality.

OBJECTIVE: To determine whether implementation of a standardized clinical practice guideline (CPG) for the evaluation of syncope would decrease practice variability and resource utilization. DESIGN: A retrospective review of medical records of patients presenting to our practice for outpatient evaluation of syncope before and after implementation of the CPG. The guideline included elements of history, physical exam, electrocardiogram, and "red flags" for further testing. SETTING: Outpatient pediatric cardiology offices of a large pediatric cardiology practice. PATIENTS: All new patients between 3 and 21 years old, who presented to cardiology clinic with a chief complaint of syncope. INTERVENTIONS: The CPG for the evaluation of pediatric syncope was presented to the providers. OUTCOME MEASURES: Resource utilization was determined by the tests ordered by individual physicians before and after initiation of the CPG. Patient final diagnoses were recorded and the medical records were subsequently reviewed to determine if any patients, who presented again to the system, were ultimately diagnosed with cardiac disease. RESULTS: Of the 1496 patients with an initial visit for syncope, there was no significant difference in the diagnosis of cardiac disease before or after initiation of the CPG: (0.6% vs. 0.4%, P = .55). Electrocardiography provides the highest yield in the evaluation of pediatric syncope. Despite high compliance (86.9%), there were no overall changes in costs ($346.31 vs. $348.53, P = .85) or in resource utilization. There was, however, a decrease in the variability of ordering of echocardiograms among physicians, particularly among those at the extremes of utilization. CONCLUSIONS: Although the CPG did not decrease already low costs, it did decrease the wide variability in echo utilization. Evaluation beyond detailed history, physical exam, and electrocardiography provides no additional benefit in the evaluations of pediatric patients presenting with syncope.

Elastic properties of the reconstructed aorta in hypoplastic left heart syndrome.

BACKGROUND: Patients with repaired coarctation of the aorta retain abnormal elastic properties of the aorta. It is not known whether patients with hypoplastic left heart syndrome also manifest abnormal elastic properties after palliative surgery. The presence of such abnormalities may have important clinical implications as reduced aortic compliance might adversely impact single right ventricular function. METHODS: We prospectively evaluated the elastic properties of the aorta in a cohort of patients with hypoplastic left heart syndrome who had undergone the Norwood procedure with aortic arch reconstruction and subsequent bidirectional Glenn or Fontan procedure. The hypoplastic left heart syndrome patients (n = 20) were compared with single-ventricle patients (n = 18) without history of arch reconstruction and patients with double-ventricular lesions (n = 22). Aortic elastic function was quantified by distensibility index and stiffness index. M-mode measurements of the transverse aortic arch were obtained with transesophageal echocardiography under general anesthesia. Patients were evaluated at a median age of 22.2 months with no age difference between patient subgroups. RESULTS: Distensibility index was significantly less (p = 0.007) and stiffness index greater (p = 0.005) in the reconstructed arch of hypoplastic left heart syndrome patients compared with single-ventricle and double-ventricle patients. CONCLUSIONS: Patients with hypoplastic left heart syndrome after Norwood palliation have increased aortic stiffness and decreased distensibility in the reconstructed transverse arch. As previous studies in adults have shown that decreased aortic compliance increases the energy cost of cardiac ejection, examination of modifications to the surgical technique that might improve elastic properties is warranted.

Reduction in initial ventricular systolic and diastolic velocities after heart transplantation in children: improvement over time identified by tissue Doppler imaging.

BACKGROUND: Tissue Doppler imaging (TDI) is a non-invasive method for measuring ventricular function that can provide insight into the changes in hemodynamics that occur after pediatric heart transplantation. The purpose of this study was to quantify longitudinal changes in myocardial velocities within the first 6 months after transplantation in children. METHODS: Thirteen patients were serially studied (median age at transplant 5.9 years) and compared with controls. Tissue Doppler systolic (S), early (E) and late (A) diastolic velocities were recorded at the tricuspid annulus, mitral annulus and interventricular septum. RESULTS: TDI studies were serially performed during 6 months post-transplantation: <10 days (n = 48); 11 to 30 days (n = 26); 31 to 60 days (n = 13); 61 to 120 days (n = 12); and 121 to 180 days (n = 16). Mean systolic tissue velocities at the tricuspid annulus were 3.8 cm/s (95% confidence interval [CI]: 3.1 to 4.6) at baseline (<10 days) and 6.3 cm/s (95% CI: 4.1 to 8.6) at 6 months post-transplantation (mean increase from baseline: 2.5 cm/s; 95% CI: 0.1 to 4.9). Systolic tissue velocities at the mitral annulus also increased over time (mean change from baseline: 0.9 cm/s; p = 0.02). Early diastolic (E) velocities at the tricuspid annulus and mitral annulus significantly improved over time (p < 0.0001 and p = 0.002, respectively). Systolic and diastolic velocities measured at >121 days after transplantation, however, remained significantly lower than those of normal controls. CONCLUSIONS: TDI demonstrated systolic and diastolic velocities improved during the initial 180 days after heart transplantation. Systolic and diastolic velocities were reduced in children after heart transplantation when compared with controls.