Cardiomyopathy means disease of the myocardium — the heart muscle itself. Ventricular size, function, or structure changes because the muscle is diseased, not because the coronary arteries are blocked, blood pressure is high, a valve is faulty, or the heart formed abnormally. That distinction — primary muscle disease versus muscle suffering from something outside itself — is the starting point for everything that follows.
The shape the ventricle takes, its phenotype, is the first useful description, but it is not the diagnosis: the same genetic disease can wear different shapes, and infiltrative diseases (abnormal material deposited between the cells) and storage diseases (material accumulating inside the cells) can move between shapes as they advance. What separates them is what the tissue is made of.
The family at a glance
Four phenotypes describe the ventricular picture, and only some of them are taught in depth here.
| Phenotype | Ventricular picture | Place in this cluster |
|---|---|---|
| Hypertrophic | Increased wall thickness, normal or small cavity | Taught directly, together with the hypertrophic appearance of early amyloidosis and early Fabry disease |
| Dilated | Enlarged cavity, thin walls, reduced systolic function | Named for orientation; no dedicated note here |
| Restrictive | Normal cavity, stiff walls, severe diastolic limitation | Met as late-stage physiology in amyloidosis; no standalone note here |
| Arrhythmogenic | Arrhythmia-predominant disease with fibrofatty replacement | Named for orientation; no dedicated note here |
Choose a route through the cluster
The notes fall into three groups: two on working up any cardiomyopathy, a series on hypertrophic cardiomyopathy, and two diseases that can look hypertrophic early on but have a different tissue basis.
- Cardiomyopathies — Diagnostic Approach: how unexplained dysfunction is worked up, from excluding ischaemic and loading causes to tissue characterisation and family screening. Start here.
- Cardiomyopathies and Cardiac MRI: the imaging gateway — what each sequence measures and how the combined tissue pattern narrows the differential.
- Hypertrophic Cardiomyopathy: the sarcomere model — asymmetric hypertrophy, its genetics, and the dynamic outflow obstruction it causes.
- Hypertrophic Cardiomyopathy — Clinical Presentation: how it comes to attention, from incidental ECG findings and exertional syncope to atrial fibrillation and stroke.
- Hypertrophic Cardiomyopathy — Athletic Heart: how physiological hypertrophy in a trained athlete is separated from mild hypertrophic cardiomyopathy.
- Hypertrophic Cardiomyopathy — Sudden Death Risk: the fibrosis and clinical factors that mark arrhythmic risk, and what they mean for defibrillator and sport decisions.
- Hypertrophic Cardiomyopathy — Treatment: medicines for the outflow gradient, septal reduction, and stroke prevention in atrial fibrillation.
- Cardiac Amyloidosis: the infiltrative model — the three cardiac types, the diffuse tissue signature, and the pathway that usually types amyloid without biopsy.
- Fabry Disease: the storage model — X-linked enzyme deficiency, its distinctive imaging signature, and why early diagnosis and family screening change outcomes.
Read the diagnostic approach and the imaging note first; the scan patterns give each disease something visible to hold on to.