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🌱 來自: cardiomyopathies

restrictive and infiltrative cardiomyopathy

definition of restrictive and infiltrative cardiomyopathy (JACC 2018;71:1130 & 1149)

Etiologies (JACC 2018;71:1130 & 1149)

• amyloidosis: age at presentation ~60 y; ♂:♀ = 3:2

AL (eg, MM, etc.); familial (transthyretin, ATTR-m); senile (ATTR-wt)

ECG: ↓ QRS amplitude (50%), pseudoinfarction pattern (Qw), AVB (10–20%), hemiblock (20%), BBB (5–20%)

Echo: biventricular wall thickening (yet w/ low voltage on ECG), granular sparkling (30%), biatrial enlargement (40%), valve thickening, small effusions

Normal ECG voltage & septal thickness has NPV ~90%

Cardiac MRI: distinct late gadolinium enhancement pattern (JACC 2008;51:1022)

• Sarcoidosis (can also be DCM): presents at age ~30 y; ↑ in blacks, N. Europe, ♀

Cardiac involvement in 25–58% of sarcoid, many not overt; cardiac w/o systemic in 10%

ECG: AVB (75%), RBBB (20–60%), VT; PET: ↑ FDG uptake in affected area

Echo: regional WMA (particularly basal septum) w/ thinning or mild hypertrophy

Cardiac MRI: T2 early gad (edema); fibrosis/scar in basal septum; LGE prognostic

• Other myocardial processes

Hemochromatosis: often middle-aged men (espec N. European); 15% w/ cardiac sx

Diabetes; radiation (also accelerated athero, valvular disease, constrictive pericarditis)

Autoimmune (scleroderma, polymyositis-dermatomyositis)

• Endomyocardial diseases: carcinoid heart disease (R-sided HF w/ TR/TS, PR/PS); Löffler’s endocarditis (↑ eos; mural thrombi that can embolize; fibrosis); endomyocardial fibrosis (tropical climates; resembles Löffler’s but w/o eos)

• Storage diseases: Fabry (glycosphingolipids); Gaucher (glucocerebrosidase)

Pathophysiology

• ↓ myocardial compliance → nl EDV but ↑ EDP → ↑ systemic & pulm. venous pressures

• ↓ ventricular cavity size → ↓ SV and ↓ CO

Clinical manifestations (JACC 2018;71:1130 & 1149)

• Right-sided >left-sided heart failure with peripheral edema >pulmonary edema

• Diuretic “refractoriness”; thromboembolic events

• Poorly tolerated tachyarrhythmias; VT → syncope/sudden cardiac death

Physical exam

• ↑ JVP, ± Kussmaul’s sign (JVP not ↓ w/ inspir., classically seen in constrict. pericarditis)

• Cardiac: ± S3 and S4, ± murmurs of MR and TR

• Congestive hepatomegaly, ± ascites and jaundice, peripheral edema

Diagnostic studies

• CXR: normal ventricular chamber size, enlarged atria, ± pulmonary congestion

• ECG: low voltage, pseudoinfarction pattern (Qw), ± arrhythmias

• Echo: ± symmetric wall thickening, biatrial enlarge., ± mural thrombi, ± cavity oblit. w/ diast dysfxn: ↑ early diast (E) and ↓ late atrial (A) filling, ↑ E/A ratio; ↓ mitral annular velocity (e′) on tissue Doppler, ↑ E/e′ ratio

• Cardiac MRI/PET: may reveal inflammation or evidence of infiltration (but nonspecific)

• Amyloid (qv) workup: ✓ for plasma cell dyscrasia (immunofix. & serum free light chains). If ⊕ → fat pad bx. If ⊖ → PYP SPECT for TTR evaluation (not AL).

• Endomyocardial biopsy if suspect amyloid (Se ~100%) & noninvasive tests non-dx. Se low for sarcoidosis b/c patchy disease infiltrative process.

• Cardiac catheterization

Atria: M’s or W’s (prominent x and y descents)

Ventricles: dip & plateau (rapid ↓ pressure at onset of diastole, rapid ↑ to early plateau)

Concordance of LV–RV pressure peaks w/ respiration (vs. discordance in constriction)

• Restrictive cardiomyopathy vs. constrictive pericarditis: see “Pericardial Disease”

Treatment (in addition to Rx’ing underlying disease)

• Gentle diuresis. May not tolerate CCB or other vasodilators.

• Control HR (but can ↓ CO); maintain SR (helps filling). Digoxin ↑ arrhythmias in amyloid.

• Anticoagulation (particularly with AF or low CO)

• Transplantation for refractory cases

• AL amyloid: Rx targeted at plasma cell dyscrasia

• ATTR amyloid: tafamidis (TTR binder) ↓ death and CV hosp, ↑QoL (NEJM 2018;379:1007)

• Sarcoid: consider steroids/immunomodulators if FDG PET ⊕ for inflammation + AVB, VT or LV dysfxn; ↑ risk for VT; unique indications for ICD placement (Circ 2018;138:e272)