Left Ventricular Outflow Tract Obstruction (LVOTO)
Hypertrophic cardiomyopathy (HCM) is a condition in which there is asymmetric hypertrophy of the myocardium. The thickened heart muscle can obstruct blood flow and prevent the heart from functioning properly.
HCM is due to a genetic disorder caused by various mutations in genes encoding sarcomeric proteins. It is an inherited disease in 50% of the cases (autosomal dominant); however, 50% of the cases are sporadic.
Symptoms and signs
Hypertrophic cardiomyopathy may present at any age. Patient may present with angina, dyspnea, syncope or sudden death (due to ventricular fibrillation). Symptoms can become exacerbated by exertion. On auscultation there will be a harsh ejection systolic murmur, S4.
1. EKG will show exaggerated septal Q waves suggestive of MI, as well as, evidence of left ventricular hypertrophy, ischemia in the inferior and lateral leads, arrhythmias (atrial fibrillation, ectopics, ventricular tachycardia or fatal ventricular fibrillation).
2. Echocardiography will reveal asymmetrical septal hypertrophy, small left ventricular cavity with dynamic obstruction due to valve motion abnormalities (anterior mitral valve).
Beta-blockers is the drug of choice for relief of symptoms.
2. Calcium channel blockers
Verapamil can also help decrease the symptoms.
3. Treatment of arrhythmias
- Amiodarone for treatment of arrhythmias.
- Anticoagulate if the patient has AF.
- Cardiac pacing if resistant to medical treatment.
4. Septal myomectomy
Surgical or chemical septal myomectomy may be used for those with severe symptoms.
5. Percutaneous transcoronary septal reduction
Percutaneous transcoronary septal reduction with alcohol may be possible in some patients.
6. Dual chamber pacing
7. Implantable cardiac defibrillators
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