Acquired cardiomyopathy caused by cardiac deposition
of amyloid leading to decreased heart function (especially contractility).
Commonly acquired secondary to multiple
myeloma. Familial forms of amyloidosis are usually inherited by an autosomal
mode resulting in mutations of transthyretin (prealbumin); 40 variants have
Deposition of amyloid occurs in the myo-
cardium, epicardium, and pericardium. Echocardiography classically shows a normal
diastolic volume, slow ventricular filling throughout diastole, minimal
shortening during systole, and high systolic volumes, resulting in a reduced
stroke volume and low cardiac output state. The left ventricle is poorly
compliant and left ventricular end-diastolic pressure is elevated.
Consequently, endocardial perfusion is dependent on maintaining diastolic
blood pressure. Localized septal deposition of amyloid protein may present
clinically as hypertrophic obstructive cardiomyopathy. Infiltration of the
conduction system may cause dysrhythmias and bundle branch block. Other
forms of restrictive cardiomyopathy may be distinguished from cardiac
amyloidosis by rapid ventricular filling early in diastole.
Clinical history and signs of cardiomyopathy.
Echocardiographic findings and demonstration of amyloid on rectal or
Evidence of cardiac amyloid is present in up to
90% of cases of primary and multiple myeloma-associated amyloidosis.
Cardiac amyloidosis is also found in association with lymphoma, rheumatoid
arthritis, tuberculosis, osteomyelitis, and bronchiectasis. The predominant
clinical features are those of cardiac failure, tachypnea, orthopnea, decreased
exercise tolerance, elevated jugular venous pressure, pulmonary edema, and
hepatic distension. The ECG may show bundle branch block or rhythm
abnormalities. The chest radiograph may show cardiomegaly (secondary to a
pericardial effusion) or pleural effusions. The ventricular failure is often
refractory to medical management.
Full medical history and physical examination
to evaluate cardiac function and significance of any associated disorders.
Proper evaluation of the restrictive nature of the cardiomyopathy must be
obtained. Respiratory assessment and chest radiograph are mandatory.
Cardiovascular assessment, ECG, and echocardiography should be performed
prior to anesthesia. Ensure optimal control of cardiac function prior to
induction of anesthesia.
Technique aimed to maintain ventricular
preload, avoid further depression of myocardial contractility, maintain
diastolic blood pressure, maintain sinus rhythm, and avoid
tachycardia/bradycardia. Use of invasive monitoring should be strongly
considered, although pulmonary artery catheters may be misleading because of
the altered left ventricular compliance.
Cardiac depressant anesthetic
medications must be used judiciously. The induction of significant
tachycardia must be prevented (e.g., pancuronium is relatively
Arora S, Arora A, Makkar RP, Monga A: Stiff heart syndrome. CMAJ
Chew C, Ziady G, Raphael M et al: The functional defect in amyloid heart
disease. The stiff heart syndrome. Am J Cardiol
Kushwaha S, Fallon J, Fuster V: Restrictive cardiomyopathy. N Engl J Med