๐ Guideline basis
2023 ESC guidelines for the management of cardiomyopathies (Arbelo E, et al., Eur Heart J 2023); ASE 2025 diastolic function update (restrictive cardiomyopathy, HCM and constriction sections); ASE/EACVI multimodality imaging recommendations in cardiac amyloidosis; ASE 2025 right heart guideline (lead-related TR).
Hypertrophic cardiomyopathy in the ICU
Critical illness is a potent provocateur of dynamic obstruction. Sepsis, hypovolaemia, catecholamines, tachycardia and vasodilatation each move the physiology in the wrong direction simultaneously, and a patient with previously asymptomatic HCM can present in refractory shock.
The three requirements for obstruction
- Reduced preload โ small LV cavity
- Increased contractility โ endogenous or exogenous catecholamines
- Reduced afterload โ vasodilatation
All three are supplied by septic shock, and all three are worsened by the reflexive treatment of hypotension with inotropes.
Findings
Asymmetric septal hypertrophy (septal:posterior wall ratio > 1.3, though any pattern occurs); systolic anterior motion of the anterior mitral leaflet; a late-peaking, dagger-shaped LVOT continuous-wave envelope, distinguishing dynamic from the earlier-peaking, symmetric envelope of fixed aortic stenosis; a posteriorly directed eccentric mitral regurgitant jet; a small, hyperdynamic cavity with end-systolic obliteration; and impaired relaxation with a reduced eโฒ.
A resting or provoked LVOT gradient โฅ 30 mmHg defines obstruction; โฅ 50 mmHg is the threshold for intervention in ambulatory practice.
The management inversion
Do | Avoid |
Volume loading | Inotropes (dobutamine, adrenaline, milrinone) |
Pure vasoconstrictor โ phenylephrine, or noradrenaline for its ฮฑ effect | Vasodilators, including nitrates and high-dose propofol |
Beta-blockade to slow the rate and reduce contractility | Tachycardia; treat pain, fever and agitation |
Restore sinus rhythm early | Loss of the atrial contribution, which is disproportionately important in a stiff ventricle |
The diagnostic clue is a patient who becomes more hypotensive as the inotrope dose is increased. Continuous-wave Doppler through the LVOT takes seconds and reverses the management plan (Chapter 28).
Cardiac amyloidosis
Increasingly recognised, frequently first suspected on an ICU echocardiogram, and highly consequential because several standard drugs are poorly tolerated.
Red flags
Domain | Finding |
Structure | Increased LV and RV wall thickness; biatrial enlargement; thickened valves and interatrial septum; small pericardial effusion |
Function | Preserved EF with a low stroke volume index; grade 3 diastolic dysfunction; E/A > 2 with markedly reduced annular velocities |
Tissue Doppler | The "5-5-5" sign โ mitral annular sโฒ, eโฒ and aโฒ all < 5 cm/s |
Strain | Apical sparing on the polar plot; ratios used include apical-to-(mid + basal) strain > 1, septal apical-to-basal ratio > 2.1, and EF/GLS ratio > 4.1 |
ECG discordance | Low or normal voltage despite marked wall thickening โ the single most useful non-imaging clue |
Association | Paradoxical low-flow, low-gradient aortic stenosis (Chapter 18) |
Why it matters acutely
The stiff, small-cavity ventricle is intolerant of the drugs used reflexively in the ICU:
- Beta-blockers โ output is rate-dependent because stroke volume is fixed
- ACE inhibitors and ARBs โ profound hypotension from an inability to compensate
- Digoxin โ binds avidly to amyloid fibrils; historically avoided, though contemporary practice is more permissive with careful monitoring
- Diuretics โ necessary for congestion but easily overshoot into preload deficit
Management is rate control avoidance, careful volume management, maintenance of sinus rhythm, and early haematology or cardiology referral for typing (light chain versus transthyretin), which determines prognosis and treatment.
Other cardiomyopathies
Entity | Key echocardiographic features | ICU relevance |
Dilated cardiomyopathy | Dilated, spherical LV; global hypokinesis; secondary functional MR; LA dilatation; possible LV thrombus | Distinguish from reversible septic cardiomyopathy (non-dilated) โ Chapter 29 |
Fulminant myocarditis | Normal or only mildly dilated cavity with severe dysfunction, increased wall thickness from oedema, pericardial effusion, marked troponin rise | The archetypal indication for temporary mechanical support: outcomes are excellent if the patient is bridged through the acute phase |
Restrictive cardiomyopathy | Normal cavity size, biatrial enlargement, E/A > 2.5, DT < 150 ms, IVRT < 50 ms, septal and lateral eโฒ 3โ4 cm/s | Distinguish from constriction: septal eโฒ is reduced in restriction, > 7 cm/s with annulus reversus in constriction (Chapters 8, 15) |
Takotsubo / stress cardiomyopathy | See Chapter 38 | Crosses coronary territories; may generate LVOT obstruction |
Tachycardia-induced cardiomyopathy | Dilated, globally impaired ventricle in a patient with sustained tachyarrhythmia; recovers with rate or rhythm control | Do not label as irreversible; treat the rhythm and reassess |
Arrhythmia and echocardiography
The haemodynamic consequences of rhythm
Rhythm problem | Consequence | Populations most affected |
Loss of atrial contraction | Loss of 20โ40% of end-diastolic volume | Restrictive physiology, HCM, amyloid, severe AS, severe MS, RV infarction |
Tachycardia | Shortened diastolic filling and coronary perfusion time | Mitral stenosis, AS, ischaemia, diastolic dysfunction |
Loss of AV synchrony (ventricular pacing, junctional rhythm) | Atrial contraction against a closed AV valve; cannon waves; falling output | Post-cardiac surgery, RV infarction |
Ventricular dyssynchrony (LBBB, RV pacing) | Prolonged IVRT, shortened filling time, septal dysfunction, functional MR | Any; also degrades septal eโฒ and therefore E/eโฒ |
In restrictive physiology, restoring sinus rhythm is a haemodynamic intervention that can raise cardiac output by 20โ30%, and it should be considered before escalating inotropes.
Pre-cardioversion assessment
Left atrial appendage thrombus must be excluded by TEE before cardioversion of atrial fibrillation of more than 48 hours' duration or of unknown duration, unless the patient has been adequately anticoagulated or is haemodynamically unstable. TTE cannot answer this question.
Device-related findings
Finding | Detail |
Lead-related tricuspid regurgitation | Impingement, adherence, entrapment or perforation of the septal leaflet; prevalence rises with lead dwell time. Frequently persists after extraction (Chapter 22) |
Pacing-induced cardiomyopathy | Progressive LV dysfunction with a high burden of RV pacing; consider upgrade to conduction-system or biventricular pacing |
Lead thrombus and vegetation | A common diagnostic problem: distinguishing fibrin sheath and thrombus from infective vegetation requires clinical context, TEE, and often ยนโธF-FDG PET/CT (Chapter 24) |
Device-related tamponade | Perforation during implantation; may present hours later; a low threshold for imaging after any device procedure |
CRT optimisation | AV and VV interval optimisation using mitral inflow filling time and LVOT VTI; the evidence for routine echocardiographic optimisation is weak, and it is not standard practice |
Reverberation artefact from leads | Mimics vegetation, flap or thrombus โ confirm in two orthogonal planes and across gain settings |
Toxicological and environmental cardiomyopathy
Echocardiography distinguishes phenotypes that look identical on the monitor and require different antidotes.
Poisoning | Haemodynamic phenotype | Echocardiographic picture | Specific therapy |
Beta-blocker overdose | Bradycardia with reduced contractility | Impaired systolic function, low VTI, slow rate | High-dose insulin euglycaemic therapy, glucagon, pacing |
Verapamil / diltiazem | Bradycardia, reduced contractility and vasodilatation | Impaired function with a low SVR | Calcium, high-dose insulin, vasopressor |
Dihydropyridine calcium blocker (amlodipine) | Vasodilatation with preserved or hyperdynamic contractility | Hyperdynamic ventricle, low SVR, high VTI | Vasopressor is the priority; inotropes are unnecessary |
Local anaesthetic systemic toxicity | Profound myocardial depression with arrhythmia | Severe global hypokinesis | Intravenous lipid emulsion; prolonged CPR; ECMO |
Sodium channel blockers (tricyclics, flecainide) | Wide-complex arrhythmia with negative inotropy | Impaired function | Sodium bicarbonate |
Hypothermia | Bradycardia with reduced contractility, expected at low temperature | Depressed function that recovers on rewarming | Do not over-treat; rewarm |
Catecholamine excess (phaeochromocytoma, exogenous) | Hyperdynamic then depressed | Takotsubo-like patterns, LVOT obstruction | Alpha blockade before beta blockade |
The dihydropyridine-versus-non-dihydropyridine distinction is the highest-yield: both present as calcium channel blocker overdose with shock, but one requires a vasopressor and the other requires inotropic and chronotropic support. Echocardiography separates them in under a minute.
๐ Critical pitfall: Escalating inotropes in a hypotensive patient with a hyperdynamic, small-cavity ventricle. HCM, amyloid, hypovolaemia and dihydropyridine overdose all present this way, and all are worsened by inotropes.
๐ Critical pitfall: Labelling a dilated, poorly contracting ventricle in a patient with sustained tachyarrhythmia as irreversible cardiomyopathy. Tachycardia-induced cardiomyopathy recovers with rhythm control.
๐ Critical pitfall: Cardioverting atrial fibrillation of uncertain duration in a stable patient without TEE exclusion of appendage thrombus.
- ๐ก Clinical pearl: A thick-walled ventricle with a normal or low ECG voltage is amyloidosis until proven otherwise, and it changes the drug list immediately.
- ๐ก Clinical pearl: In fulminant myocarditis, the ventricle is often not dilated but is severely impaired, with wall thickening from oedema. It is one of the best indications for temporary mechanical support because recovery is common.
- ๐ก Clinical pearl: In any undifferentiated poisoning with shock, a two-minute study answering "hyperdynamic or depressed?" and "fast or slow?" narrows the antidote list faster than the toxicology screen returns.
References
- Arbelo E, Protonotarios A, Gimeno JR, et al. 2023 ESC guidelines for the management of cardiomyopathies. Eur Heart J 2023;44:3503โ626.
- Nagueh SF, Sanborn DY, Oh JK, et al. ASE 2025 diastolic function update. J Am Soc Echocardiogr 2025;38:537โ69.
- Dorbala S, Ando Y, Bokhari S, et al. ASNC/AHA/ASE/EANM/HFSA/ISA/SCMR/SNMMI expert consensus recommendations for multimodality imaging in cardiac amyloidosis. J Nucl Cardiol 2019;26:2065โ123.
- American Society of Echocardiography. Guidelines for the echocardiographic assessment of the right heart in adults and special considerations in pulmonary hypertension. J Am Soc Echocardiogr 2025.
- Champion S, et al. Dynamic left ventricular outflow tract obstruction. Can J Cardiol 2020. PMID 33173359.