Hypertrophic cardiomyopathy (HCM) is a cardiac disorder characterised by unexplained non-dilated ventricular hypertrophy, highly variable clinical presentation and early mortality. At least 50% of cases are familial, with HCM inherited in an autosomal dominant manner. Linkage and molecular analyses have identified involvement of the cardiac-myosin heavy chain gene (MYH7) locus on chromosome 14, band q11-12, in approximately 50% of HCM-affected families. At least 12 different mutations responsible for HCM have been identified in MYH7. The involvement of MYH7 with HCM in two South African families of mixed racial ancestry were investigated by genetic linkage analysis, using polymorphic DNA markers at chromosome 14q11 - 12.
The presence of sinus bradycardia (less than 6O/min) in patients affected by progressive familial heart block type I (PFHB1) and their inability to reach a target heart rate during exercise testing, prompted an investigation of the influence of the autonomic nervous system on cardiac conduction in these family members.
A young patient with a primary cardiac tumour, in whom the diagnosis was confirmed by two-dimensional echocardiography (2DE). and magnetic resonance imaging (MRI), is descriptionbed. Primary cardiac tumours are rare; however, this report emphasises their existence.