Stiff Heart Syndrome

Acquired cardiomyopathy caused by cardiac deposition of amyloid leading to decreased heart function (especially contractility).

Cardiac Amyloidosis.

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 been described.

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 endocardial biopsy.

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 contraindicated).