Uhl anomaly
Uhl anomaly is an unusual cardiac disorder which affects the right ventricle where there is an almost complete absence of right ventricular myocardium, normal tricuspid valve, and preserved septal and left ventricular myocardium.
Clinical presentation
Presentation usually occurs in the neonatal and childhood years with clinical aspects of congestive heart failure. The presentation may vary from arrhythmia induced syncope or sudden cardiac death to a syndrome consistent with isolated right-sided heart failure, including :
- hepatomegaly
- jugular venous distension
- dyspnea
- cyanosis
ECG
- sinus rhythm
- multi-component epsilon waves
- present throughout the limb leads and precordium
- sharp deflection at the J point (the junction between the QRS complex and the ST segment)
- initial deflection followed by a variable number of oscillations
- right atrial enlargement
- multi-component epsilon waves
- arrhythmias
- monomorphic ventricular tachycardia
- precordial leads demonstrate a morphology similar to a left bundle branch block (LBBB)
- the frontal plane QRS axis will be deviated in a superior direction
- monomorphic ventricular tachycardia
Radiographic features
Echocardiography
Non-specific features suggestive of Uhl's anomaly may be detected on a fetal echocardiography examination, including marked dilation of the right ventricle, with reduced wall thickness.
In postnatal life, supportive findings on transthoracic echocardiography include the following:
- global right ventricular dysfunction
- all right ventricular segments thinned (< 2 mm)
- lack wall thickening during systole
- wall motion will be akinetic or dyskinetic
- severe impairment of systolic and diastolic RV function indices
- all right ventricular segments thinned (< 2 mm)
- right atrial enlargement
- right ventricular dilation
- accompanied by paradoxical septal motion
- associated congenital cardiac anomalies may include:
- tricuspid valve malformations
- especially Ebstein's anomaly
- tricuspid atresia
- atrial septal defects
- patent ductus arteriosus
- tricuspid valve malformations
History and etymology
It is named after Henry S D Uhl, who first described the condition in 1952 .
Differential diagnosis
Imaging differential considerations include:
- arrhythmogenic right ventricular cardiomyopathy: there is fibro-fatty infiltration of the right ventricular wall
- Ebstein anomaly: the tricuspid valve is abnormal and there is atrialization of the right ventricle
