A Pilot Study Assessing ECG versus ECHO Ventriculoventricular Optimization in Pediatric Resynchronization Patients.

INTRODUCTION: Cardiac resynchronization therapy indications and management are well described in adults. Echocardiography (ECHO) has been used to optimize mechanical synchrony in these patients; however, there are issues with reproducibility and time intensity. Pediatric patients add challenges, with diverse substrates and limited capacity for cooperation. Electrocardiographic (ECG) methods to assess electrical synchrony are expeditious but have not been extensively studied in children. We sought to compare ECHO and ECG CRT optimization in children. METHODS: Prospective, pediatric, single-center cross-over trial comparing ECHO and ECG optimization with CRT. Patients were assigned to undergo either ECHO or ECG optimization, followed for 6 months, and crossed-over to the other assignment for another 6 months. ECHO pulsed-wave tissue Doppler and 12-lead ECG were obtained for 5 VV delays. ECG optimization was defined as the shortest QRSD and ECHO optimization as the lowest dyssynchrony index. ECHOs/ECGs were interpreted by readers blinded to optimization technique. After each 6 month period, these data were collected: ejection fraction, velocimetry-derived cardiac index, quality of life, ECHO-derived stroke distance, M-mode dyssynchrony, study cost, and time. Outcomes for each optimization method were compared. RESULTS: From June 2012 to December 2013, 19 patients enrolled. Mean age was 9.1 ± 4.3 years; 14 (74%) had structural heart disease. The mean time for optimization was shorter using ECG than ECHO (9 ± 1 min vs. 68 ± 13 min, P < 0.01). Mean cost for charges was $4,400 ± 700 less for ECG. No other outcome differed between groups. CONCLUSION: ECHO optimization of synchrony was not superior to ECG optimization in this pilot study. ECG optimization required less time and cost than ECHO optimization.

Improvement in the assessment of diastolic function in a clinical echocardiography laboratory following implementation of a quality improvement initiative.

BACKGROUND: The aim of this study was to demonstrate improvement in the characterization of diastolic function in the routine practice of a clinical echocardiography laboratory after the implementation of a quality improvement initiative. The echocardiographic analysis of left ventricular (LV) diastolic dysfunction is an inherently complex process involving the integration of multiple indices for accurate assessment. METHODS: A baseline survey of 50 randomly chosen echocardiographic studies was reviewed for the accuracy of diastolic function assessment. A four-step quality improvement protocol was then initiated: (1) sonographer and physician education; (2) the implementation of data acquisition protocol changes using LV inflow, tissue Doppler velocity of the mitral annulus in early diastole (e'), flow propagation velocity of LV inflow (Vp), and left atrial volume index (LAVI), along with the establishment of uniform criteria for diagnostic interpretation; (3) peer review of performance; and (4) focused interactive case review sessions. RESULTS: At baseline, measurements of LV inflow were most often correct (100% accurate), while measurements of e' (82% accurate), Vp (12% accurate), and LAVI (12% accurate) and the proper classification of diastolic function (44% accurate) were significantly limited. After the quality improvement initiative, there were significant increases in the accuracy of all recorded measurements, with e' 92% accurate (a 10% improvement; P < .10), Vp 67% accurate (a 55% improvement; P < .001), LAVI 80% accurate (a 68% improvement, P < .001), and proper characterization of diastolic function 76% accurate (a 32% improvement, P < .001). CONCLUSIONS: A multifaceted quality improvement protocol including staff education, systematic support with enhanced infrastructure, and peer review with feedback can be effective for improving the clinical performance of a nonacademic echocardiography laboratory in the characterization of diastolic function.

Evaluation of the noninvasive estimates of cardiac output by Doppler aortoechography according to test-theoretical principles.

The usability of noninvasive methods can be quantified by a formal assessment of empirical quality criteria based on test-theoretical principles. The ACVF Doppler aortoechography is a pulsed dual-beam ultrasound technique with online estimates of cardiac output (CO) based upon the measurement of the mean Doppler shift frequency across the ascending aorta, its estimated cross-sectional area and the cycle's heart rate. The method has a relatively high reliability, sensitivity, and pharmacosensitivity (for inodilatory changes in particular), but tends to underestimate cardiac output. Furthermore, the method lacks objectivity because it is highly observer-dependent. Precise method description and stringent standardization thus are required. Because of the method specificity of its estimates, data should not be combined with those of other methods. The inherently poor validity of its CO estimates, using this method, call for caution in the mechanistic interpretation of its observations.