Pieces of educational information

Hypertrophic obstructive cardiomyopathy (HOCM) is an autosomal dominant disorder of muscle tissue caused by defects in the genes encoding contractile proteins. Mutations to various proteins including beta-myosin, alpha-tropomyosin and troponin T have been identified. Septal hypertrophy causes left ventricular outflow obstruction. It is an important cause of sudden death in apparently healthy individuals.

Poor prognostic factors

syncope
family history of sudden death
young age at presentation
non-sustained ventricular tachycardia on 24 or 48-hour Holter monitoring
abnormal blood pressure changes on exercise

An increased septal wall thickness is also associated with a poor prognosis.

HOCM - poor prognostic factor on echo = septal wall thickness of > 3cm

Cardiology , MRCP-1

Hypertrophic obstructive cardiomyopathy - poor prognosis

Dr. Kibria Thursday, August 4, 2016

Ventricular septal defects are the most common cause of congenital heart disease. They close spontaneously in around 50% of cases. Non-congenital causes include post myocardial infarction. Atrial fibrillation is associated more with atrial septal defects.

Features

classically a pan-systolic murmur which is louder in smaller defects Complications
aortic regurgitation*
infective endocarditis
Eisenmenger's complex
right heart failure

* aortic regurgitation is due to a poorly supported right coronary cusp resulting in cusp prolapse

Cardiology , MRCP-1

Associations of Ventricular septal defects

Dr. Kibria

Percutaneous coronary intervention (PCI) is a technique used to restore myocardial perfusion in patients with ischaemic heart disease, both in patients with stable angina and acute coronary syndromes. Stents are implanted in around 95% of patients - it is now rare for just balloon angioplasty to be performed.

Following stent insertion migration and proliferation of smooth muscle cells and fibroblasts occur to the treated segment. The stent struts eventually become covered by endothelium. Until this happens there is an increased risk of platelet aggregation leading to thrombosis.

Two main complications may occur

stent thrombosis: due to platelet aggregation as above. Occurs in 1-2% of patients, most commonly in the first month. Usually presents with acute myocardial infarction
restenosis: due to excessive tissue proliferation around stent. Occurs in around 5-20% of patients, most commonly in the first 3-6 months. Usually presents with the recurrence of angina symptoms. Risk factors include diabetes, renal impairment and stents in venous bypass grafts

Types of stent

bare-metal stent (BMS)
drug-eluting stents (DES): stent coated with paclitaxel or rapamycin which inhibit local tissue growth. Whilst this reduces restenosis rates the stent thrombosis rates are increased as the process of stent endothelisation is slowed

Following insertion the most important factor in preventing stent thrombosis is antiplatelet therapy. Aspirin should be continued indefinitely. The length of clopidogrel treatment depends on the type of stent, reason for insertion and consultant preference.

Diabetes mellitus is a risk factor for restenosis rather than stent thrombosis.

Cardiology , MRCP-1

Percutaneous coronary intervention - complications

Dr. Kibria

Mitral valve prolapse is common, occurring in around 5-10 % of the population. It is usually idiopathic but may be associated with a wide variety of cardiovascular disease and other conditions.

Associations

congenital heart disease: PDA, ASD
cardiomyopathy
Turner's syndrome
Marfan's syndrome, Fragile X
osteogenesis imperfecta
pseudoxanthoma elasticum
Wolff-Parkinson White syndrome
long-QT syndrome
Ehlers-Danlos Syndrome
polycystic kidney disease

Features

patients may complain of atypical chest pain or palpitations
mid-systolic click (occurs later if patient squatting)
late systolic murmur (longer if patient standing)
complications: mitral regurgitation, arrhythmias (including long QT), emboli, sudden death

Whilst some patients with acromegaly have mitral valve prolapse (MVP) it is not a common association. It should be remembered that the prevalence of MVP in a standard population is around 5-10%

Cardiology , MRCP-1