Ventricular Functional Analysis in Congenital Complete Heart Block Using Speckle Tracking: Left Ventricular Epicardial Compared to Right Ventricular Septal Pacing.

BACKGROUND: Chronic right ventricular (RV) apical pacing in patients with congenital complete atrioventricular block (CCAVB) is associated with left ventricle (LV) dyssynchrony and dysfunction. Hence, alternative pacing sites are advocated. The aim of this study was to compare LV function using STE in selected patients with LV epicardial pacing (LVEp) vs. RV transvenous pacing (RVSp). METHODS: This was a single-center, retrospective study in patients with CCAVB who underwent permanent pacemaker implant at age ≤ 18 years. Age- and gender-matched patients with a normal heart anatomy and function served as the control group. LV function was comprehensively assessed by conventional 2D Echocardiography and speckle-tracking echocardiography (STE). RESULTS: We included 24 patients in the pacemaker group [27.6% male, mean age of 17.1 at last follow-up, follow-up duration of 8.7 years, RVSp (n = 9; 62.5%)] compared to 48 matched healthy controls. Shortening fraction (SF) and ejection fraction (EF) were normal and similar between cases and controls. However, STE detected abnormal LV function in the pacemaker group compared to controls. The former demonstrated lower/abnormal, Peak Longitudinal Strain myocardial (PLS Myo) [- 12.0 ± 3.3 vs. - 18.1 ± 1.9, p < 0.001] and Peak Longitudinal Strain endocardial (PLS endo) [- 16.1 ± 4.1 vs. 1.7 ± 1.7, p < 0.001]. STE parameters of LV function were significantly more abnormal in LVEp vs. RVSp subgroup as demonstrated by lower values for PLS Myo (- 10.1 ± 3.2 vs. - 13.1 ± 2.9, p = 0.03) and PLS Endo (- 13.8 ± 4.4 vs. - 17.5 ± 3.3, p = 0.03). CONCLUSION: STE was more sensitive in detecting subtle differences in LV function relative to standard conventional 2D echocardiography (SF and EF) in selected patients with CCAVB and a permanent pacemaker. Furthermore, STE demonstrated that transvenous RV septal pacing was associated with better LV systolic function preservation than LV epicardial pacing for comparable post-implant intervals.

Successful Explantation of Berlin Heart Excor in Two Young Children.

Berlin Heart EXCOR ventricular assist device (VAD) implantation in children is widely used as bridge-to-heart transplantation. Berlin left ventricular assist device (LVAD) support as a bridge to recovery is rare. There is a scarcity of literature describing systematic evaluation in pediatric VAD explantation. Patient 1. A 3 month old boy presented with acute heart failure secondary to myocarditis. An echocardiogram demonstrated severely depressed left ventricular function. He required ECMO cannulation and was decannulated 11 days later. He continued to be hemodynamically unstable and required Berlin LVAD implantation with the intent to bridge to transplantation. Patient 2. A 3 month old boy presented initially with a heart rate of 250 beats/min and an electrocardiogram showed multifocal atrial tachycardia. An echocardiogram showed severely decreased left ventricular function. He was placed on ECMO due to unstable hemodynamics. He did not tolerate ECMO decannulation due to persistent chaotic atrial rhythm and underwent Berlin LVAD implantation with the intent to bridge to transplantation. After both patients showed evidence of myocardial recovery, they underwent a weaning protocol that includes: screening, trial-off with echocardiography, and trial-off in the catheterization suite. Our patients met the criteria and underwent successful explantation. Explantation of VAD can be successfully performed even in young children with appropriate candidate selection and a multidisciplinary and systematic approach.

Cardiac Amyloidosis in a Child Presenting with Syncope: The First Reported Case and a Diagnostic Dilemma.

Cardiac amyloidosis is a rare cause of cardiomyopathy, reported exclusively in adults. We report the first known case presenting in childhood. A 12-year-old boy presented with syncope and diagnosed with ventricular non-compaction by echocardiography. Eventual genetic testing confirmed a TTR gene mutation associated with hereditary transthyretin amyloidosis.