HCM Flashcards
What is the definition of hypertrophic cardiomyopathy?
Hypertrophic cardiomyopathy (HCM) is defined by the presence of increased left ventricular (LV) wall thickness that is not solely explained by abnormal loading conditions.
What factors define HCM?
One of most common inherited cardiovascular disorders.
Defined by presence of left ventricular hypertrophy in the absence of any other cause of LVH.
Caused largely by mutations in the sarcomeric genes.
Autosomal dominant
Cause of sudden cardiac death.
1-200 to 1:500 in the population, depending if subclincal included.
Affects male and female equally but women get diagnosed less or later.
What is the aetiology of HCM?
- In up to 60% of adolescents and adults with HCM the disease is an autosomal dominant trait caused by mutations in cardiac sarcomeric genes.
- Metabolic disorders:
- Mitochondrial cardiomyopathies
- Neuromuscular disorders
- Malformation syndromes.
- Infiltrative disease/inflammation
- Endocrine disorders
Who concluded hypertrophic cardiomyopathy history as paradigm of an inherited cardiovascular disorder?
Donal Teare
How can HCM be characterised in concern to pathology?
DISARRAY
SMALL VESSELS DISEASE
FIBROSIS
What is a recognised feature of hypertrophic cardiomyopathy but is not equal to the diagnosis of the condition?
Left ventricularoutflow tract obstruction(LVOTO). Gradient in outflow increased due to non fixed effect.
What does Imaging: Mechanisms of left ventricular outflow tract obstruction present?
Left Ventricular hypertrophy Mitral valve leaflets Subvalvular apparatus Papillary muscles Aortic root angulation Inotropic status Rotation of heart apex
What are two of the most common causes of familial HCM?
Cardiac myosin-binding protein C and Cardiac Beta-myosin heavy chain
What is part of the diagnostic criteria for HCM?
Adults: HCM>=15 mm in one of more LV myocardial segments- as measured by any imaging technique- that it is not explained solely by loading conditions.
Children: LVH>2 SD than predicted z-score.
Genetic and non-genetic disorders can present with lesser degrees of wall thickening (13–14 mm);
Diagnosis requirements: family history, non-cardiac symptoms and signs, electrocardiogram (ECG) abnormalities, laboratory tests and multi-modality cardiac imaging.
What challenges the diagnosis of HCM?
- Presentation in the late phase of the disease with a dilated and/or hypokinetic left ventricle and LV wall thinning
- Physiological hypertrophy caused by intense athletic training
- Patients with co-existent pathologies :
HTN and Valve disease. - Isolated basal septal hypertrophy in
elderly people
How is the clinical diagnosis of HCM in relatives/ gene carries/ subclinical diseases pursued?
The clinical diagnosis of HCM in first-degree relatives of patients with unequivocal disease (LVH equal to or exceeds 15mm) is based upon presence of otherwise unexplained increased LV wall thickness equal to or exceeding 13mm in one or more LV myocardial segments, as measured using any cardiac imaging technique (echocardiography, cardiac magnetic resonance (CMR) or CTI).
What increases probability disease on relative?
Incomplete systolic anterior motion (SAM), elongated mitral valve leaflets, numerous crypts, abnormal papillary muscles, low positive predictive value (PPV) in isolation, higher in with +fH.
How is ECG used to diagnose HCM?
> 95% have an abnormal ECG.
ECG is more abnormal in younger patients.
ECG changes overtime
ECG changes can be present years before left ventricular hypertrophy
What is ECG in HCM useful for?
Diagnosis
SCD Risk assessment
TE Risk
Myocardial Ischemia
Follow-up and management
Echo-Guide in ASA
LVOT Obstruction MR evaluation
What comprises the systematic echocardiographic approach?
- Left ventricle
- LVOTO
- Mitral Valve
- Left atria
- Right ventricle
