Hypertrophic cardiomyopathy Hypertrophic cardiomyopathy is a disease in which there is significant hypertrophy of the myocardium in the absence of a known etiology. It is becoming clear that many cases of hypertrophic cardiomyopathy may be due to a gene mutation, specifically in the gene coding for myosin or troponin. There may or may not be a dynamic left ventricular outflow tract obstruction with concomitant mitral regurgitation. The pathophysiology of symptoms occurring in patients with hypertrophic cardiomyopathy is complex and due to diastolic function abnormalities, the outflow obstruction, mitral regurgitation, and arrhythmia. Echocardiography has been essential in establishing the diagnosis and delineating the pathophysiology - increased use of echocardiography has made it clear that what was thought to be a rare disorder with a grave prognosis is more common with a more benign prognosis.
Pregnancy is generally well tolerated in patients with hypertrophic cardiomyopathy.
The increased blood volume is beneficial in terms of its effect on the left ventricular outflow tract obstruction. Sudden death is rare and the incidence is probably not increased in pregnancy. Treatment during pregnancy depends upon the pathophysiology of the individual patient. Beta blockers are commonly used in the presence of a high outflow gradient and are well tolerated. A selective B1 blocker should be used to avoid premature uterine contraction.