Pathophysiology
Sarcomere dysfunction (TTN truncating variants ~20% of familial), inflammation (viral, autoimmune), toxins (alcohol, anthracyclines, cocaine), tachycardia-mediated (persistent SVT/AF), stress cardiomyopathy (Takotsubo), and endocrine (thyroid, phaeochromocytoma) all converge on LV dilation and systolic dysfunction.
Sources: 2022 AHA/ACC/HFSA Heart Failure Guideline (Circulation 2022;145:e895); ESC Heart Failure Guideline (Eur Heart J 2021;42:3599); AHA Scientific Statement DCM (Circulation 2016;134:e579)
Clinical presentation
Signs of heart failure - dyspnoea, orthopnoea, PND, fatigue, oedema. Displaced apex, S3 gallop, functional mitral regurgitation, arrhythmias (AF, VT), thromboembolism, and sudden cardiac death.
Diagnosis
ECG, chest x-ray (cardiomegaly), NT-proBNP, and transthoracic echocardiogram (LV dilation with LVEF <=40%). Cardiac MRI for tissue characterisation (late gadolinium enhancement suggests myocarditis, sarcoid, or infiltrative disease). Genetic testing when familial pattern or DCM <50 y.
Management
Quadruple GDMT for HFrEF: ARNI (or ACEi/ARB), evidence-based beta-blocker (carvedilol, bisoprolol, metoprolol succinate), MRA (spironolactone/eplerenone), and SGLT2 inhibitor (dapagliflozin/empagliflozin). Loop diuretics for congestion. ICD for LVEF <=35% >=90 days on GDMT; CRT if QRS >=150 ms LBBB. Anticoagulate for AF/LV thrombus. Alcohol cessation, immunosuppression for selected myocarditis.
Advanced HF
Cardiac transplantation and LVAD for stage D HF; palliative care and multidisciplinary follow-up.
