Assessing Non-invasive Studies to Evaluate Resynchronization Pacing Effectiveness in the Young.

Appropriate non-invasive assessments (ECHO/ECG) of cardiac resynchronization pacing therapy (CRT) among younger patients (pts) with/without (w/wo) congenital heart disease (CHD) are not established. Ejection fraction (EF) and QRS can be unreliable due to anatomy, surgical repairs, and pre-existing pacemakers (PM). This study correlates updated non-invasive studies, including newer strain values, with clinical and invasive hemodynamic assessments of CRT response in the young. Sixteen pts (mean age 18.5 ± 6 years, 10/16 with pre-existing pacemakers) underwent CRT for heart failure (NYHA II-III). CHD included septal defects and Tetralogy of Fallot. Assessment of CRT efficacy was based on clinical findings, direct catheterization studies [pressures, contractility indices (dP/dt-max)], ECG changes, and ECHO studies [including updated global (GLS), left atrial strain (LAS), and sphericity indices] pre- and at 1-month and 1-year post-CRT. After 1 year following CRT, all pts improved (II-III to I-II) in clinical NYHA status. Contractility (dP/dt) increased (932 ± 351 vs 561 ± 178.7 mmHg-sec [p = 0.001]). QRS duration shortened only among pts with pre-existing PM (160 ± 25 vs 134 ± 25 ms [p = 0.02]). Standard ECHO parameters, including chamber dimensions and EF, showed no appreciable changes from pre-CRT values. However, endocardial GLS [(- 6.4 vs. - 9.6%) p = 0.0003] and LAS [(- 5.8 vs - 9.3%) p = 0.02] values significantly improved. Although CRT is applicable to younger pts, accurate non-invasive evaluations of response are lacking. This study establishes that newer strain values better correlate with clinical and hemodynamic changes over other parameters and offer more appropriate assessments of CRT response.

Anthracycline Treatment and Left Atrial Function in Children: A Real-Time 3-Dimensional Echocardiographic Study.

Anthracycline (AC) therapy is associated with left ventricular (LV) dysfunction. Left atrial (LA) size and function are used to assess LV diastolic function in heart failure in adults. Data on LA size and function following AC therapy in children is limited. We hypothesized that LA size and function will be abnormal in children following AC chemotherapy. This retrospective review included patients who received AC for pediatric cancers. Controls had normal echocardiograms performed for evaluation of chest pain, murmur, or syncope. Real-time three-dimensional echocardiography was performed to evaluate LA reservoir, conduit, and booster pump function parameters. In addition to LA volume data, LV shortening fraction, spectral and tissue Doppler variables assessing diastolic function as well as myocardial performance index was obtained. Groups with and without AC therapy were compared by student t-test and chi-square test. We evaluated 136 patients, 55 (40.4%) had received AC. There was no significant difference between the groups in LV shortening fraction, diastolic as well as global function indices. LA reservoir and conduit function parameters were significantly lower in AC group compared to controls. The booster function parameters showed variable results. It is intriguing that AC-treated children have smaller LA reservoir and abnormal booster function. We speculate that these findings may reflect early changes in LA compliance associated with AC exposure. Assessment of LA volumes and function as prognostic markers of AC-induced cardiotoxicity in children is warranted.

Spontaneous closure of muscular ventricular septal defect by growth of right ventricular muscle bundles: a rare mechanism.

We present a case of an 18-year-old male with large anterior muscular ventricular septal defect. Assessment by echocardiography showed that the defect has completely closed by the growth of muscle bundles that formed a pouch-like structure on the right ventricular side. This unusual mechanism of closure has been reported in one prior case report. In our report, we present images obtained by three-dimensional echocardiography.

Left ventricle segmental function in childhood cancer survivors using speckle-tracking echocardiography.

AIM: Anthracycline-associated cardiotoxicity in childhood cancer survivors may relate to global or segmental left ventricular abnormalities from associated thromboembolic events and myocardial microinfarcts. We characterized left ventricular segmental changes by two-dimensional speckle-tracking echocardiography in anthracycline-treated asymptomatic childhood cancer survivors. METHODS AND RESULTS: Childhood cancer survivors' echocardiograms with normal left ventricular fractional shortening >1 year after anthracycline chemotherapy were studied. Cancer-free control children had normal echocardiograms. Apical two-, three-, and four-chamber peak systolic left ventricular longitudinal and global longitudinal strain, and peak systolic left ventricular radial and circumferential strain at papillary muscle levels were analyzed. The mean (standard deviation) age was 12.7 (3.8) years in 41 childhood cancer survivors. The median (interquartile range) follow-up after anthracycline chemotherapy was 4.73 (2.15-8) years. The median (range) cumulative anthracycline dose was 160.2 (60-396.9) mg/m2. In childhood cancer survivors, the mean (standard deviation) left ventricular longitudinal strain was lower in two- (-18.6 [3.2] versus -21.3 [2.5], p < 0.001), three- (-16.3 [6.0] versus -21.7 [3.0], p < 0.001), and four- (-17.6 [2.7] versus -20.8 [2.0], p < 0.001) chamber views compared to controls. The left ventricular global longitudinal strain (-17.6 [2.7] versus -21.3 [2.0]) and circumferential strain (-20.8 [4.3] versus -23.5 [2.6], p < 0.001) were lower in childhood cancer survivors. Among childhood cancer survivors, 12 out of 16 left ventricular segments had significantly lower longitudinal strain than controls. CONCLUSIONS: Asymptomatic anthracycline-treated childhood cancer survivors with normal left ventricular fractional shortening had lower global longitudinal and circumferential strain. The left ventricular longitudinal strain was lower in majority of the segments, suggesting that anthracycline cardiotoxicity is more global than regional.

Pediatric malignancies: Is the prechemotherapy left ventricular function normal?

PURPOSE: We compared the left ventricular (LV) systolic function in children with cancer before initiation of chemotherapy with matched controls using speckle tracking echocardiography. METHODS AND RESULTS: In this retrospective study, we analyzed the echocardiograms of 89 cancer patients before the initiation of chemotherapy and 82 age- (8.4 ± 5.2 vs. 8.9 ± 3.9 years, P = .4) and gender-matched (64% vs. 67%, males, P = .4) healthy controls. Peak systolic LV longitudinal strain (LS) was significantly lower in cancer patients in apical two (-19.8 ± 3.0 vs. -23.5 ± 4.0, P < .001), three (-19.4 ± 3.2 vs. -23.4 ± 4.0, P < .001), and four-chamber views (-19.7 ± 3.4 vs. -22.5 ± 3.0, P < .001) compared to controls, as was global longitudinal strain (GLS) (-19.8 ± 2.7 vs. -23.4 ± 3.2, P < .001). The prechemotherapy group also had a higher E/e' ratio compared to controls at the septal (9.3 ± 3.9 vs. 7.9 ± 1.7, P = .005) and lateral annulus (7.9 ± 3.3 vs. 5.9 ± 1.4, P < .001) of the mitral valve. The LV ejection fraction was lower in cancer patients compared to controls (63.5 ± 4.9 vs. 66.8 ± 4.1, P < .001), although still within normal limits. There were no differences in LV myocardial performance index (0.30 ± 0.05 vs. 0.30 ± 0.09, P < .65) and shortening fraction (35.8 ± 5.2 vs. 36.1 ± 6.1, P < 0.75) between the two groups. Subgroup analysis showed no difference in LV GLS between patients with solid tumors (n = 56) and blood cancers (n = 33) (GLS -19.2 ± 2.9 vs. 19.5 ± 2.4, P > 0.05). CONCLUSION: Our data demonstrating abnormalities in LV GLS in pediatric cancer patients even prior to initiation of chemotherapy are novel and perplexing. Further longitudinal follow-up is required to assess the implications of this abnormal LV function in these patients.