Dilated cardiomyopathy
Volumes and EF, secondary MR, filling pressure, the RV, thrombus — and the numbers that trigger devices.
Numbers to remember
- HFrEF LVEF ≤40%, HFmrEF 41–49%, HFpEF ≥50% [12,37]
- LVEF ≤35% after ≥3 months of optimal therapy → primary-prevention ICD / CRT pathway [12,38,39]
- Improved EF: baseline ≤40%, rise ≥10 points to >40% [37]
- Severe secondary MR: EROA ≥0.4 cm², RVol ≥60 mL (flow-convergence methods underestimate) [4,6]
- COAPT profile: LVEF 20–50%, LVESD ≤70 mm, severe MR on GDMT [64]
Questions echo must answer
Dilated cardiomyopathy is LV dilatation with systolic dysfunction that is not explained by abnormal loading conditions or coronary disease. Hypokinetic non-dilated cardiomyopathy is the same disease without dilatation [14,144]. Echo classifies the heart-failure phenotype by LVEF [12,37], finds the cause-specific clues, and gives the numbers for device and valve decisions.
- Size and functionBiplane volumes and LVEF, GLS, LV mass, sphericity [1,88,89].
- Aetiology cluesRegional versus global dysfunction (ischaemic?), hypertrabeculation, thin versus thick walls, tachycardia, peripartum timing, alcohol or chemotherapy history.
- ConsequencesSecondary MR, filling pressure, pulmonary pressure, RV function and RV–PA coupling, TR [2,3,57].
- ComplicationsLV thrombus, low output [140].
- Serial changeReverse remodelling on therapy, measured by the same method each time [68,69,71].
Acquisition protocol
- PLAXMeasure LVIDd and LVIDs, wall thickness and LA size. Check for a mitral–septal separation.
- A4C / A2CBiplane method of discs for EDV, ESV and EF. Avoid foreshortening: the true apex tapers and is thin [1]. Use contrast if two or more contiguous segments are not seen [1].
- StrainGLS from A4C, A2C and A3C on the same vendor as previous studies [16,90].
- MitralRecord the MR mechanism (tethering, annular dilatation), vena contracta, PISA EROA and RVol, and CW density [4,34].
- DiastolicRecord E/A, E/e′, LAVI, TR velocity, and pulmonary vein flow or LA strain when indeterminate [2,32].
- OutputLVOT VTI × LVOT area for SV, SVI and CI. Doppler dP/dt from the MR jet [118].
- RVRecord TAPSE, S′, FAC and RV free-wall strain, TAPSE/PASP and TR [3,52].
- ApexLook for thrombus in every view, with contrast if the image quality is limited [140].
- IVCEstimate RA pressure [3,50].
- Biplane volumes and LVEF
- GLS
- MR mechanism and EROA and RVol
- E/e′, LAVI, TR velocity
- SV, SVI and CI; dP/dt
- TAPSE, S′, TAPSE/PASP
- Apical thrombus excluded
- Comparison with the previous study (same method)
Diagnosis & severity
| Measure | Threshold | Implication |
|---|---|---|
| LVEF | ≤40% / 41–49% / ≥50% | HFrEF / HFmrEF / HFpEF [12,37] |
| LVEDV index | Above sex-specific normal (men >74, women >61 mL/m²) | Dilatation [1] |
| LVEF without dilatation | <45% | Hypokinetic non-dilated cardiomyopathy [144] |
| GLS | Worse (less negative) values predict death independent of EF | Prognosis [88,89] |
| Secondary MR | EROA ≥0.4 cm², RVol ≥60 mL, VC ≥7 mm | Severe [4,6] |
| TAPSE/PASP | <0.31 mm/mmHg | RV–PA uncoupling, worse outcome [52,77] |
| Restrictive filling (E/A ≥2, DT <160 ms) | Present | Raised LAP, worse prognosis [2] |
NoteThe 2021 universal definition calls a rise from ≤40% by ≥10 points to >40% HF with improved EF. It is a new category, not a cure: TRED-HF showed relapse in about 40% within 6 months when therapy was withdrawn [37,70].
Thresholds that change management
- LVEF ≤35% despite ≥3 months of optimal medical therapy → primary-prevention ICD in selected patients, with CRT if QRS ≥130–150 ms with LBBB [12,38,39].
- Repeat echo after 3–6 months of GDMT before device decisions. Sacubitril/valsartan and SGLT2 inhibitors produce measurable reverse remodelling [68,69].
- Secondary MR → optimise GDMT and CRT first. Transcatheter edge-to-edge repair benefits patients who fit the COAPT profile (disproportionate MR: large EROA relative to a not-too-dilated LV). MITRA-FR (proportionate MR, larger LVs) showed no benefit [64,185,186].
- LV thrombus → anticoagulation, with follow-up imaging at about 3 months [140].
- Myocardial work or coupling can help interpret an EF that looks better only because afterload fell [156,157].
Pitfalls & mimics
PitfallForeshortened apical views underestimate volumes and overestimate EF, and hide apical thrombus. Look for a thin, tapering apex, and use contrast when in doubt [1].
- Atrial fibrillation: average EF, VTI and E/e′ over at least 5 beats, or use index beats after similar RR intervals [2].
- Linear (Teichholz) EF is invalid in regional dysfunction and misleading in dilated, spherical ventricles [1,42].
- Inter-vendor GLS differences of 1–3 percentage points: compare only like with like [90].
- PISA underestimates elliptical, crescentic secondary MR orifices. Combine it with VC, CW density, pulmonary vein flow and volumetric methods [4].
- Mimics: ischaemic cardiomyopathy (regional pattern, scars), tachycardia-induced cardiomyopathy (recovers with rate control), myocarditis, LV non-compaction (NC/C >2 in systole), and athlete's heart with low-normal EF that rises with exercise [14,150].