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Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Dilated cardiomyopathy

Cardiology · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
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Escalate

Syncope with ventricular arrhythmia, cardiogenic shock, pulmonary oedema or rapidly progressive conduction disease requires urgent monitored admission and senior cardiology input.

Synopsis

Recognise the DCM phenotype, find reversible and inherited causes, treat heart failure and prevent arrhythmic death.

  • DCM is LV or biventricular dilatation with systolic dysfunction not explained solely by abnormal loading or coronary disease.
  • A normal coronary angiogram identifies non-ischaemic dysfunction; it does not establish an idiopathic diagnosis.
  • Ask specifically about family sudden death, alcohol, pregnancy, myocarditis, chemotherapy, toxins and neuromuscular features.
  • CMR defines ventricular phenotype and scar; mid-wall or ring-like fibrosis can materially alter arrhythmic risk.
  • Treat the HFrEF phenotype promptly while investigating its cause; do not wait for genetic results.
  • Genotype, fibrosis, syncope and ventricular arrhythmia can justify ICD discussion even when LVEF is above a simple threshold.
  • A pathogenic result should trigger genetic counselling and cascade testing; a negative panel does not erase familial risk.
  • Recovery of LVEF is remission, not proof of cure: continue disease-modifying therapy unless a specialist gives a compelling reason to stop.

Key red flags

High-risk course

Unexplained syncope, sustained VT, extensive scar, severe biventricular failure or progressive conduction block signals risk beyond symptoms or LVEF alone.

Shock or pulmonary oedema

Cold peripheries, confusion, oliguria, hypotension, hypoxia or severe respiratory distress needs immediate acute-heart-failure care.

Investigation priorities

01
12-lead ECG and ambulatory rhythm monitoringFirst step

Detect AF, conduction disease and ventricular arrhythmia.

Management branches

AcuteDecompensation or shock

Pulmonary oedema, hypoperfusion or serious arrhythmia.

  1. Assess ABCDE, continuous ECG, oxygen only if hypoxaemic, IV access, renal/electrolytes, troponin/NT-proBNP and urgent bedside echo.
  2. Treat congestion with IV loop diuretic; if shock persists, escalate immediately to critical care and an advanced-heart-failure centre for inotrope or mechanical-support assessment.
  3. Correct a precipitant such as ACS, infection, AF/VT, medication interruption or toxicity; cardiovert an unstable tachyarrhythmia without delaying for aetiological work-up.
  4. Once perfusion and renal function permit, introduce or re-establish disease-modifying HFrEF therapy before discharge with early review.
ChronicHFrEF and arrhythmic protection

Stable DCM after congestion is controlled.

  1. Offer the NICE HFrEF disease-modifying combination at tolerated doses: ACE inhibitor or ARNI/ARB as appropriate, evidence-based beta-blocker, MRA and SGLT2 inhibitor; titrate with BP, renal function and potassium surveillance.
  2. Use loop diuretic for residual congestion, counsel on salt/fluid only when clinically indicated, vaccination, alcohol avoidance and graded rehabilitation.
  3. After optimisation, reassess LVEF, symptoms, scar, genotype, syncope and ventricular arrhythmia; discuss ICD/CRT where criteria or phenotype-specific risk support it.

Key medicines

Dapagliflozin10 mg orally once daily for chronic HFrEF.Check renal function and volume status; pause during major surgery or acute serious illness and assess suspected ketoacidosis even if glucose is not markedly raised.
SpironolactoneUsually 25 mg orally once daily; reduce or titrate according to renal function, potassium and response.Hyperkalaemia and renal deterioration; check U&E before and shortly after starting or dose change. Avoid potassium supplements unless specifically directed.
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Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

  • 2023 ESC Guidelines for the management of cardiomyopathiesPhenotype, aetiology, genetics and integrated arrhythmic-risk framework.
  • NICE NG106: Chronic heart failure in adultsCurrent UK HFrEF drug and monitoring pathway.
  • NHS Genomics Education: Dilated cardiomyopathyInherited features, testing and family implications.
  • NICE TA314: Implantable cardioverter defibrillators and CRTUK device eligibility framework.
  • NHS: CardiomyopathyUK presentation and patient safety-netting context.

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom
  • If deterioration continues despite therapy, refer early for advanced therapies rather than waiting for irreversible end-organ failure.