No abstract

Genetic testing is recommended in patients with dilated cardiomyopathy (DCM); however, limited studies demonstrate high yields of genetic testing in non-hypertrophic (HCM) patients. Furthermore, there is sparse genotype-phenotype data in pediatric DCM patients. We performed a retrospective review of 70 consecutive probands with cardiomyopathy (non-HCM) who underwent genetic evaluation. Mean age at presentation was 5.48 years. Echocardiography revealed mean ejection fraction of 32.4%. The LVEDd z score ranged from - 5.7 to + 15.9. Cardiomyopathy was classified as dilated in 56, 10 with non-compaction, 2 with restrictive, and 2 with ARVC. TTN gene mutations were the most common gene involved. Genetic testing was negative in 16/70 (23%) giving a yield of 77% including VUS. 33% (23/70) of probands had a positive family history among whom the diagnostic yield was 57% (13/23) for pathogenic mutations. Yield for positive genetic testing in the DCM with positive family history group was 9/18 (50%). There were 6 deaths (9%) and 26/70 (37%) underwent transplantation. More frequent cardiac transplantations (48 vs. 34%) and deaths (17 vs. 2%) were seen in mutation-positive vs. mutation-negative subgroups. This study demonstrates an increasing yield of genetic testing in DCM although with a high rate of VUS detection. Use of genetic information for better management and prognostication will require big data analysis.

Additional evidence is required to ascertain the degree to which vision screening is effective. The processes of screening are multiple, sequential, and complicated. The disease is complex, and good visual outcomes require compliance. The value of outcomes is appropriately analyzed in clinical, human, and economic terms.

Objectives: We investigated the efficacy and complication profile of intranasal dexmedetomidine for transthoracic echocardiography sedation in patients with single ventricle physiology and shunt-dependent pulmonary blood flow during the high-risk interstage period. Methods: A single-centre, retrospective review identified interstage infants who received dexmedetomidine for echocardiography sedation. Baseline and procedural vitals were reported. Significant adverse events related to sedation were defined as an escalation in care or need for any additional/increased inotropic support to maintain pre-procedural haemodynamics. Minor adverse events were defined as changes from baseline haemodynamics that resolved without intervention. To assess whether sedation was adequate, echocardiogram reports were reviewed for completeness. Results: From September to December 2020, five interstage patients (age 29–69 days) were sedated with 3 mcg/kg intranasal dexmedetomidine. The median sedation onset time and duration time was 24 minutes (range 12–43 minutes) and 60 minutes (range 33–60 minutes), respectively. Sedation was deemed adequate in all patients as complete echocardiograms were accomplished without a rescue dose. When compared to baseline, three (60%) patients had a >10% reduction in heart rate, one (20%) patient had a >10% reduction in oxygen saturations, and one (20%) patient had a >30% decrease in blood pressure. Amongst all patients, no significant complications occurred and haemodynamic changes from baseline did not result in need for intervention or interruption of study. Conclusions: Intranasal dexmedetomidine may be a reasonable option for echocardiography sedation in infants with shunt-dependent single ventricle heart disease, and further investigation is warranted to ensure efficacy and safety in an outpatient setting.

Introduction: Coarctation of the aorta (CoA) severity is assessed via trans-CoA blood pressure gradient (BPG) estimated using simplified Bernoulli equation (SBE) with indices from noninvasive Doppler echocardiography (echo). However, simplifications of the SBE and inconsistent readings through a suboptimal insonation window limit diagnostic accuracy (DA). In a rabbit model mimicking human CoA (Fig. 1A), catheter vs. Doppler comparison of BPG revealed diastolic continuous-flow pressure gradient (CFPG) was independently associated with severity. We therefore hypothesized the unique properties of CFPG would improve DA in humans. Methods: SBE and CFPG were quantified using color flow Doppler in humans and rabbits with discrete non-recurrent CoA before repair (Fig. 1B). Quantifications used peak velocity proximal to (V p ) and at the CoA (V pk ), early diastolic velocity (V d ), doppler velocity index (DVI), and normalized diastolic pressure half-time (dPHT; see Fig. 1B and C for definitions). Results were compared with measured BPG in rabbits (peak-to-peak catheter BPG) and humans (upper-lower extremity BPG). There was a total of 18 human and 26 rabbit cases; significance was defined a priori as a BPG of ≥20 mmHg. A CFPG ≥4 mmHg threshold was identified by maximizing sensitivity plus specificity in receiver operative curves (ROC). Results: Accuracy measures (Fig. 1D) revealed the superior performance of CFPG vs. SBE. Although reports suggest <60% of measured BPG can be explained with SBE, CFPG yielded a specificity of 78% in humans. Similar improvements were observed in rabbits. Results confirm the potential DA of CFPG in echo-based CoA assessment. Fig. 1- (A) MRI confirming morphological similarities between rabbit and human CoA, (B) Spectral Doppler images show diastolic continuous flow, (C) indices derived from the generalized Bernoulli equation assuming exponential diastolic pressure loss, (D) diagnostic performance for CFPG vs. conventional SBE.