Interventional treatments for hypertrophic cardiomyopathy

Multi-modality management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant inherited condition defined by left ventricular wall thickness greater than 15 mm in the absence of other conditions that could explain that degree of hypertrophy. Obstructive HCM associated with left ventricular outflow tract obstruction is defined by an intraventricular systolic pressure gradient greater than or equal to 30 mm Hg. Over the past couple of decades, there has been an expansion of both invasive and pharmacotherapeutic options for patients with HCM, with recent guidelines calling for a melody of invasive and non-invasive treatment strategies. There are several invasive therapies including proven therapies such as alcohol septal ablation and septal myectomy. Novel invasive therapies such as MitraClip, radiofrequency septal ablation and SESAME procedure have more recently been promoted. Pharmacological therapy has also dramatically evolved and includes conventional medications such as beta-blockers, calcium channel blockers, and disopyramide. Mavacamten, a novel cardiac myosin inhibitor, may significantly change management. Other myosin inhibitors and modulators are also being developed and tested in large clinical trials. Given significant phenotypical variability in patients with HCM, clinical management can be challenging, and often requires an individualized approach with a combination of invasive and non-invasive options.

Using whole exome sequencing and bioformatics in the molecular autopsy of a sudden unexplained death syndrome (SUDS) case

Whole exome sequencing (WES) and bioinformatics analysis were used to investigate potential disease-causing gene mutations in a sudden unexplained death syndrome (SUDS) case after autopsy and pathology tests failed to suggest an obvious disease mechanism. Following whole exome sequencing, a 3-step bioinformatics filtering procedure was carried out to identify possible pathogenic genomic features. Single nucleotide variations (SNVs) were analyzed and ranked by likely mutation impact using various open online tools. After screening, we identified G643S as a putative causative heterozygous mutation in the KCNQ1 gene. This mutation has been reported in abnormalities consistent with SUDS, such as IKs in cardiac myocytes, a condition that predisposes for arrhythmias. Our work demonstrates the application of sequencing technology at the whole exome level for determining potential causes of an otherwise unexplained death.