Uhl Anomaly

At a glance

An extremely rare congenital heart defect characterized by a near total absence of the myocardium of the parietal wall of the right ventricle resulting in severe dilatation and early congestive cardiac failure. Increased right heart volumes, severe diffuse hypokinesis, and tricuspid valve regurgitation. Fatal without intervention.

Synonym

Parchment Right Ventricle.

Incidence

Very rare; less than 100 cases described.

History

Congenital disorder first described by H. S. Uhl in 1952.

Genetic inheritance

Autosomal dominant with reduced penetrance. Generally sporadic cases caused by mutations or the results of exposure to toxic or infective agents.

Pathophysiology

Not precisely known. Postulated to be the result of primary nondevelopment of myocytes or the result of an unrestrained myocardial apoptosis.

Diagnosis

The diagnosis of right ventricular cardiomyopathy is based on the echocardiographic and angiographic documentation of localized or widespread structural and dynamic abnormalities involving mainly or exclusively the right ventricle. The absence of valvular disease, intracardiac shunts, active myocarditis, and/or coronary disease is essential to establish the diagnosis. The performance of endomyocardial biopsy is considered very useful in the differential diagnosis. The prognosis varies greatly from being lethal in the neonatal period to long-term survival in other individuals.

Clinical aspects

The major clinical feature is the presentation of different types of arrhythmias with a left bundle branch block pattern. The most important electrocardiographic abnormalities are T-wave inversion in the right precordial leads and the presence of late potentials in signal averaging ECG. There is a risk of sudden death and syncopal attacks due to ventricular fibrillation; however, most of the time the arrhythmias are well tolerated. Affected individuals often have good exercise tolerance and do not have a history of previous myocarditis. Congestive cardiac failure is the main sign; it may be associated with massive peripheral edema or massive pleural effusion leading to cardiac tamponade. Pulmonary atresia can be associated.

Precautions before anesthesia

Evaluate the cardiac function (clinical, ECG, echocardiography, chest radiographs), and the extent of the pulmonary involvement (clinical, radiographs, arterial blood gas analysis). Also assess the hepatic function (clinical, laboratory investigation including coagulation test, ultrasound) because of the potential hepatic disturbance secondary to cardiac congestion.

Anesthetic considerations

Elective surgical procedures must be postponed until the cardiovascular function has been corrected. Patients presenting with congestive heart failure should not receive anesthesia for nonurgent procedures. The presence of pericardial and/or pleural effusions should be treated proper to induction of anesthesia. Anesthetic agents should be primarily chosen on the basis of their effects on the pulmonary resistance (eg, nitrous oxide, ketamine, etc.). The pulmonary ...