Cardiomyopathy — the plain-language one-pager.

What is Cardiomyopathy?Diagnosis

Cardiomyopathy is a disease of the heart muscle itself — not the arteries (CAD), not the valves (AVD), not the rhythm (AFib). The muscle becomes too thick (hypertrophic, HCM), too stretched and weak (dilated, DCM), too stiff (restrictive, RCM), or scarred and electrically unstable (arrhythmogenic, ARVC). All four can cause heart failure, dangerous arrhythmias, and sudden cardiac arrest. Many cardiomyopathies are genetic — finding one in a family member changes everything for relatives.

• HCM (hypertrophic) — the most common genetic cardiomyopathy (~1 in 500). Heart muscle thickens; can obstruct blood flow out of the heart. Leading cause of sudden death in young athletes. Treatable: beta-blockers, mavacamten, septal myectomy, ICD when indicated.
• DCM (dilated) — heart enlarges and weakens. Causes range from genetic to viral myocarditis to alcohol to peripartum to chemotherapy. GDMT (the heart-failure four pillars: ARNI/ACEi, beta-blocker, MRA, SGLT2 inhibitor) reverses some DCM.
• RCM (restrictive) — heart muscle becomes stiff. Includes amyloidosis — once a death sentence, now treatable with tafamidis (ATTR) or chemotherapy/transplant (AL).
• ARVC (arrhythmogenic) — right ventricle scars; high arrhythmia risk; another major cause of athlete sudden death. ICD is often life-saving.

Family screening — the most important next stepKnow your plan

Most cardiomyopathies are genetic, even when no family history is obvious. A new diagnosis in one person should trigger an evaluation in their first-degree relatives — even healthy ones. Many SCA deaths in young people are first presentations of an undiagnosed family cardiomyopathy.

• Genetic counseling + testing — for the affected person first; the result guides cascade screening.
• First-degree relatives — parents, siblings, children — get an ECG and echocardiogram, repeated periodically through adolescence into adulthood.
• Sports clearance — known HCM, ARVC, or familial DCM patients need individualized exercise prescriptions.
• ICD criteria are evolving — primary prevention for high-risk HCM and most ARVC; survivor of cardiac arrest = ICD almost always.
• Pregnancy + cardiomyopathy — peripartum cardiomyopathy and pre-existing genetic cardiomyopathy both need a multidisciplinary plan.

Your daily Force FieldLive It

• Take all GDMT/condition-specific meds every day — beta-blocker, ACE/ARNI, MRA, SGLT2 inhibitor for DCM/HFrEF; mavacamten for obstructive HCM if prescribed; tafamidis for ATTR amyloid.
• Know your ejection fraction — it is the headline number that drives ICD eligibility, prognosis, and therapy intensity.
• If you have an ICD, know your shock plan and the call-the-team rules.
• Cardiac rehab — adapted exercise programs improve outcomes in DCM specifically; HCM and ARVC need individualized prescriptions.
• Sodium <2,000 mg/day if heart failure is part of your picture; daily home weight; daily home BP.
• No tobacco, limit alcohol (especially in DCM where alcohol can be the cause); treat sleep apnea; healthy weight.
• Cascade family screening — ECG + echo for first-degree relatives; consider genetic counseling.
• Vaccines up to date — flu, COVID, pneumococcal, RSV when eligible. Viral infections worsen heart failure.

Red flags — call nowAction

• Call your clinic the same day for: new chest discomfort with exertion that goes away with rest (stable angina worth evaluating); a missed dose of antiplatelet or statin; medication side effects (muscle aches, bleeding, GI symptoms).
• Bring up at next visit: any change in exercise tolerance, lipid follow-up timing, BP log review, smoking-cessation support, depression screening, sleep concerns.