Myoarchitectural disarray – the multiscalar disorganisation of myocytes, is a recognised histopathological hallmark of adult human hypertrophic cardiomyopathy (HCM). It occurs before the establishment of left ventricular hypertrophy (LVH) but its early origins and evolution around the time of birth are unknown. Our aim is to investigate whether myoarchitectural abnormalities in HCM are present in the fetal heart. We used wild‐type, heterozygous and homozygous hearts (n = 56) from a Mybpc3‐targeted knock‐out HCM mouse model and imaged the 3D micro‐structure by high‐resolution episcopic microscopy. We developed a novel structure tensor approach to extract, display and quantify myocyte orientation and its local angular uniformity by helical angle, angle of intrusion and myoarchitectural disarray index, respectively, immediately before and after birth. In wild‐type, we demonstrate uniformity of orientation of cardiomyocytes with smooth transitions of helical angle transmurally both before and after birth but with traces of disarray at the septal insertion points of the right ventricle. In comparison, heterozygous mice free of LVH, and homozygous mice showed not only loss of the normal linear helical angulation transmural profiles observed in wild‐type but also fewer circumferentially arranged myocytes at birth. Heterozygous and homozygous showed more disarray with a wider distribution than in wild‐type before birth. In heterozygous mice, disarray was seen in the anterior, septal and inferior walls irrespective of stage, whereas in homozygous mice it extended to the whole LV circumference including the lateral wall. In conclusion, myoarchitectural disarray is detectable in the fetal heart of an HCM mouse model before the development of LVH.

Funding Acknowledgements Type of funding sources: None. Introduction Aortic dilatation is most commonly associated with hypertension, bicuspid aortic valve and connective tissue diseases such as Marfan’s. It is a precursor to life threatening complications such as rupture or dissection of the aorta. The current ESC Guidelines recommend surgical intervention once the aortic diameter is >50 mm in patients with Marfan syndrome (Ic) and >55 mm in patients with a bicuspid or normal aortic valve morphology (IIb). There is currently a lack of literature on the prevalence of aortic dilatation in the general or even hospital population although there is historical data suggesting the incidence of thoracic aortic aneurysm to be 5.9 cases per 100,000. Purpose The aim is to investigate the prevalence of aortic dilatation by echocardiography in our hospital population which may help lay the foundation for population studies and identify prognostic factors which may determine the time of surgical intervention. Methods We carried out a retrospective survey using the digital echocardiogram archive and the electronic patient record system at our hospital. This survey covered the period between 1st October 2016 and 1st November 2018. For randomisation  purposes, all transthoracic echocardiograms (TTE) performed on every Thursday during this period were included. All patients with an echocardiographic report of aortic root or ascending aorta dilatation were enrolled. Other information including echocardiographic dimensions along with demographics and past medical history was collected. Results During this 24-month period, we analysed a total of 3019 TTEs. 209 patients (6.9%) were reported to have aortic dilatation. 137 (66%) were male and the median age was 67 years. The mean height and weight were 169cm and 80kg, respectively.  A bicuspid aortic valve was confirmed in 10 (4.8%) patients. 132 (63%) patients had a history of hypertension. On echocardiogram, 75 (36%) patients had septal hypertrophy and 26 (12.4%) had a dilated left ventricle.   Conclusion Our findings are unique and for the first time, to our knowledge, we report the echocardiographic prevalence of aortic dilatation in the hospital population (6.9%). It is a staggering 40-fold increase when compared to the the prevalence of aortic aneurysm, the most likely end point of aortic dilatation. Based on our figures, there would be at least 400 patients with a dilated aorta in a year in our hospital alone. The prevalence of bicuspid aortic valve in our cohort (4.8%) was nearly three times higher than the general population where it is quoted as 1-2%. Our study also emphasised the established link between hypertension and aortic dilatation with an increased frequency in our cohort (63%) compared to the global prevalence (31%). Given the devastating sequelae of aortic dilatation and its increased prevalence in our patient population, it will be very important to keep these patients under routine surveillance and particularly those with hypertension.

Background  Takotsubo syndrome (TS) is defined as transient left ventricular dysfunction, which is often related to an emotional or physically stressful event. We describe a case of TS in a lady with pyruvate carboxylase deficiency (PCD). Pyruvate carboxylase deficiency is rare condition with the majority of those affected demonstrating signs of failure to thrive, recurrent seizures, and metabolic acidosis. To our knowledge, this is the first documented case of TS in an individual with PCD. Case summary  This 28-year-old female presented to the emergency department after a tonic-clonic seizure. For 4 days prior to the presentation, she had been suffering from cough and pyrexia. On Day 2, she developed abdominal pain associated with tachycardia and hypotension, and an elevated troponin (791 ng/L). The echocardiogram showed a severely impaired left ventricular systolic function, regional wall motion abnormalities (RWMAs), and a visually estimated left ventricular ejection fraction of 25–30%. Eight days following admission her clinical state significantly improved, with a reduction troponin to 60 ng/L. A repeat echocardiogram on Day 9 showed complete resolution of cardiac function with no RWMAs. Following this, she was discharged from hospital the next day with a diagnosis of TS. Discussion  This is the first case report of TS in a patient with PCD. In this case, multiple aetiologies of TS such as emotional and physical stress, seizures, and acute infection were considered. This case also highlights that TS should be an important differential diagnosis in patients presenting with cardiac symptoms.

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