This gradient represents the degree of obstruction that has to be overcome in order to eject blood from the left ventricle.The Brockenbrough–Braunwald–Morrow sign is observed in individuals with HCM with outflow tract gradient. This sign can be used to differentiate HCM from aortic stenosis. In individuals with aortic stenosis, after a premature ventricular contraction (PVC), the following ventricular contraction will be more forceful, and the pressure generated in the left ventricle will be higher. Because of the fixed obstruction that the stenotic aortic valve represents, the post-PVC ascending aortic pressure will increase as well. In individuals with HCM, however, the degree of obstruction will increase more than the force of contraction will increase in the post-PVC beat. The result of this is that the left ventricular pressure increases and the ascending aortic pressure decreases, with an increase in the LVOT gradient.While the Brockenbrough–Braunwald–Morrow sign is most dramatically demonstrated using simultaneous intra-cardiac and intra-aortic catheters, it can be seen on routine physical examination as a decrease in the pulse pressure in the post-PVC beat in individuals with HCM. Screening
Although HCM may be asymptomatic, affected individuals may present with symptoms ranging from mild to critical heart failure and sudden cardiac death at any point from early childhood to seniority. HCM is the leading cause of sudden cardiac death in young athletes in the United States, and the most common genetic cardiovascular disorder.
Oculopharyngodistal myopathy is a rare genetic disorder characterized by progressive muscle weakness affecting various parts of the body. Signs and symptoms
People with this condition exhibit symptoms susch as progressive muscle weakness affecting the eyes, face, and pharynx which consequently results in blepharoptosis, ophthalmoparesis, atrophy of the facial muscles, dysphagia, dysarthria, and muscle weakness and atrophy of the upper and lower distal limbs. These symptoms usually start during adulthood.On rare cases, hearing loss, severe proximal weakness and/or unilateral muscle weakness. Complications
Complications vary depending on the symptoms and their severity, for example, muscle weakness might leave people unable to work on manual labor jobs. Diagnosis
This condition can be diagnosed through physical examination and sequencing of the genes associated with the condition. Genetics
There are four known genetic causes of this disorder:
1. Trinucleotide repeat expansion located in the 5-prime untranslated region of the LRP12 gene. (CGG)2. Trinucleotide repeat expansion located in the 5-prime untranslated region of the G1PC gene. (GGC)3. Trinucleotide repeat expansion located in the non-coding region of the NOTCH2NLC gene. (CGG)4. Trinucleotide repeat expansion located in the 5-prime untranslated region of the RILPL1 gene.All of these mutations are inherited/expressed in an autosomal dominant manner, meaning that for a person to exhibit the symptoms of this condition, they must inherit a copy of the mutated allele from at least one parent, although in other cases, the mutation might not have been inherited, but rather the result of a spontaneous error.