AKT · Cardiovascular/Failure & myocardium

Dilated cardiomyopathy

Dilatation and impaired systolic contraction of one or both ventricles

Overview

Ventricular dilatation with impaired systolic function not explained by loading or coronary disease. Causes include genetic/familial, alcohol, peripartum, viral myocarditis, chemotherapy (anthracyclines, trastuzumab) and thyroid disease. Presents as heart failure, arrhythmia or thromboembolism, and is treated as HFrEF with the four pillars plus cause-specific measures.

Recognise

Heart failure symptoms/signs (dyspnoea, oedema, raised JVP, displaced diffuse apex, 3rd heart sound) with a globally dilated heart
Arrhythmias (AF, ventricular) and mural thrombus/embolism; functional mitral regurgitation
Causes: familial, alcohol, peripartum, post-viral myocarditis, cardiotoxic chemo, haemochromatosis, thyroid disease

Red flags

Ventricular arrhythmia/syncope with low EF → ICD assessment
Peripartum onset → specialist obstetric-cardiology care; avoid subsequent pregnancy if EF not recovered

Differentials & how to tell them apart

Ischaemic cardiomyopathyregional wall-motion abnormality, coronary disease on angiography

Hypertrophic cardiomyopathythickened, non-dilated, hyperdynamic ventricle — opposite morphology

Valvular heart diseaseprimary valve lesion driving the dilatation

Investigations

Echo (dilated, poorly contracting ventricles, low EF); ECG; cardiac MRI (aetiology/fibrosis); bloods incl. TFTs, ferritin/transferrin saturation; coronary assessment to exclude ischaemia; genetic testing/family screening; alcohol history.

Management

Treat as HFrEF (four pillars) + remove the cause (alcohol/cardiotoxin/thyroid)

1Confirm on echo/MRI and identify a reversible cause (alcohol, thyroid, iron, peripartum, cardiotoxic drugs). Start HFrEF therapy.Gate: Familial DCM → cascade genetic screening of first-degree relatives, even if asymptomatic.
2Optimise the four pillars, anticoagulate for AF/thrombus, and assess for CRT/ICD; abstinence/cause-removal can recover function.

HFrEF four pillars (ACEi/ARB/ARNI + beta-blocker + MRA + SGLT2 inhibitor) — as for any HFrEF

Treat the cause — alcohol abstinence, correct thyroid/iron, stop cardiotoxic drugs

Anticoagulation — for AF or documented mural thrombus

Device therapy (CRT/ICD) — selected patients with low EF/broad QRS

Key points

Globally dilated, poorly contracting heart with HFrEF and no coronary cause = dilated cardiomyopathy → look hard for alcohol, thyroid, iron, peripartum and cardiotoxic drugs; treat as HFrEF and screen the family.

Monitor & prognosis

Serial echo (recovery), arrhythmia surveillance, family screening.

Variable; some recover with cause-removal, others progress to advanced HF.

Source: ESC cardiomyopathy guidance; NICE NG106