Exaggerated myocardial torsion may contribute to dynamic left ventricular outflow tract obstruction in hypertrophic cardiomyopathy.

Aims: Dynamic left ventricular (LV) outflow tract obstruction (LVOTO) is associated with symptoms and increased risk of developing heart failure in hypertrophic cardiomyopathy (HCM). The association of LVOTO and LV twist mechanics has not been well studied in HCM. The aim of the study was to compare the pattern of LV twist in patients with HCM associated with asymmetrical septal hypertrophy with and without LVOTO. Methods and results: Echocardiography (including speckle tracking) was performed in 212 patients with HCM, divided according to the absence (n = 130) or presence (n = 82) of LVOTO (defined as peak pressure gradient ≥30 mmHg either at rest and/or with Valsalva manoeuvre). Patients with LVOTO were older, had smaller LV dimensions, a higher LV ejection fraction (LVEF), a longer anterior mitral valve leaflet length, and a higher early transmitral pulsed wave to septal tissue Doppler velocity ratio (E/E'). A univariate analysis showed that peak twist was significantly higher in patients with LVOTO compared with patients without LVOTO (19.7 ± 7.3 vs. 15.7 ± 6.0, P = 0.00015). Peak twist was similarly enhanced in patients with LVOTO, manifesting only during Valsalva (19.2 ± 5.6, P = 0.007) and patients with resting LVOTO (19.9 ± 8.0, P = 0.00004) compared with patients without LVOTO (15.7 ± 6.0). A stepwise forward logistic regression analysis showed that LVEF, LV end-systolic dimension indexed to body surface area, anterior mitral valve leaflet length, E/E', and peak twist were all independently associated with LVOTO. Conclusion: This study demonstrates that increased peak LV twist is independently associated with LVOTO in patients with HCM. Peak twist was similarly exaggerated in patients with only latent LVOTO, suggesting that it may play a contributory role to LVOTO in HCM.

Global longitudinal strain as a prognostic marker in cardiac resynchronisation therapy: A systematic review.

PURPOSE: Cardiac resynchronisation therapy (CRT) has proven mortality benefits for heart failure patients with moderate to severe systolic left ventricular dysfunction and evidence of a left bundle branch block. Determining responders to this therapy can be difficult due to the presence of myocardial fibrosis and scar. Left ventricular global longitudinal strain (LV GLS) is a robust and sensitive measure of myocardial function and fibrosis that has significant prognostic value for a plethora of cardiac pathologies. Our aim was to perform a systematic review of the value of LV GLS for predicting outcomes in patients undergoing CRT. METHODS: A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) protocol for reporting on systematic reviews and meta-analyses. An electronic search of all English, adult publications in EMBASE, MEDLINE/PubMed and the Cochrane Database of Systematic reviews was undertaken. RESULTS: The search yielded, 9 studies that included 3,981 patients with symptomatic heart failure, undergoing CRT implantation with LV GLS utilised as a predictor of all-cause mortality, cardiovascular death, rehospitalisation, LVAD implantation/ heart transplantation or left ventricular reverse remodelling. Significant heterogeneity was observed in study outcome measures, included populations, LV-GLS cut-offs and follow-up definitions, resulting in the inability to reliably conduct a meta-analyses. Overall, pre-CRT LV GLS was found to be a predictor of outcome post CRT insertion. CONCLUSIONS: In conclusion, all studies implied that incrementally abnormal baseline LV GLS pre-CRT implantation was associated with a long term poorer outcome.

Pregnancy Following Heart Transplantation: A Single Centre Case Series and Review of the Literature.

BACKGROUND: Maternal and fetal outcomes of pregnancy amongst cardiac transplant recipients are limited in the current literature. METHODS: We describe five pregnancies in three cardiac transplant recipients managed between a tertiary centre for obstetric medicine and an associated state-wide transplant centre between 2014-2018, and provide a narrative review of the literature. RESULTS: Pre-conception counselling was undertaken. There were no recent rejection episodes and all women demonstrated good baseline cardiac function. Median maternal age was 27 years (range 23-38 yrs.). Median time from transplantation to pregnancy was 5 years (range 2-14 yrs.). All women were managed with modified immunosuppressant regimens and multidisciplinary care. Cardiac function, tacrolimus levels and renal function were closely monitored with frequent monitoring for common complications of pregnancy. There were no maternal or fetal deaths. There was no evidence of graft rejection and no deterioration in cardiac function. Tacrolimus doses were increased to maintain therapeutic targets. Gestational diabetes occurred in three women and cholestasis of pregnancy occurred in one. Each infant was delivered by vaginal delivery. One mother had postpartum haemorrhage in both pregnancies. Pre-eclampsia did not occur. Median gestation at delivery was 37 weeks (range 35+4-40+5 days) with two preterm deliveries. One (1) infant was born with low birth weight. One (1) infant had jaundice requiring phototherapy. All infants were breastfed. CONCLUSION: Pregnancy in transplant recipients confers risk to the mother and fetus. Pre-conception counselling, immunosuppressant tailoring and regular monitoring are paramount to avoid rejection and possible teratogenic complications. Favourable pregnancy outcomes are achievable with specialist multidisciplinary care.