Ebstein's anomaly
Ebstein's anomaly | |
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Pathological specimen and ultrasound image of a heart with Ebstein's anomaly: Abbreviations: RA: right atrium; ARV: atrialized right ventricle; FRV: functional right ventricle; AL: anterior leaflet; SL: septal leaflet; LA: left atrium; LV: left ventricle; asterisk: grade II tethering of the tricuspid septal leaflet | |
Specialty | Cardiology |
Ebstein's anomaly is a
Signs and symptoms
The annulus of the valve is still in the normal position. The valve leaflets, however, are to a varying degree, attached to the walls and septum of the right ventricle. A subsequent "atrialization" of a portion of the morphologic right ventricle (which is then contiguous with the right atrium) is seen. This causes the right atrium to be large and the anatomic right ventricle to be small in size.[citation needed]
- S3 heart sound
- S4 heart sound
- Triple or quadruple gallop due to widely split S1 and S2 sounds plus a loud S3 and/or S4
- Systolic murmur of tricuspid regurgitation = Holosystolic or early systolic murmur along the lower left sternal border depending on the severity of the regurgitation
- Right atrial hypertrophy
- Right ventricular conduction defects
- Wolff-Parkinson-White syndromeoften accompanies
Related abnormalities
While Ebstein's anomaly is defined as the congenital displacement of the tricuspid valve towards the apex of the right ventricle, it is often associated with other abnormalities.[citation needed]
Anatomic abnormalities
Typically, anatomic abnormalities of the tricuspid valve exist, with enlargement of the anterior leaflet of the valve. The other leaflets are described as being plastered to the endocardium.[citation needed] Tethering the underlying ventricular wall is the most common for the posterior and septal leaflets, and sail-like anterior leaflets may be tethered to the RV free wall also.[citation needed]
About 50% of individuals with Ebstein's anomaly have an associated shunt between the right and left atria, either an
Electrophysiologic abnormalities
About 50% of individuals with Ebstein's anomaly have an accessory pathway with evidence of Wolff-Parkinson-White syndrome, secondary to the atrialized right ventricular tissue. This can lead to abnormal heart rhythms including atrioventricular re-entrant tachycardia.[citation needed]
Other abnormalities that can be seen on the ECG include:
- signs of right atrial enlargement or tall and broad 'Himalayan' P waves
- first degree atrioventricular block manifesting as a prolonged PR-interval[7]
- low amplitude QRS complexes in the right precordial leads
- atypical right bundle branch block
- T wave inversion in V1-V4 and Q waves in V1-V4 and II, III and aVF.[8]
Risk factors
An enlargement of the
Diagnosis
An echocardiogram is the most common and specific way to diagnose Ebstein’s anomaly because it effectively shows all 4 chambers of the heart, which displays the distance between the hinge point of the septal leaflet of the tricuspid valve and the anterior leaflet of the mitral valved (displacement index) to determine if the value is greater than 8mm/m2.[11]
Treatment
Medication
Ebstein's cardio physiology typically presents as an (antidromic) AV reentrant tachycardia with associated
].If atrial fibrillation with pre-excitation occurs, treatment options include procainamide, flecainide, propafenone, dofetilide, and ibutilide, since these medications slow conduction in the accessory pathway causing the tachycardia and should be administered before considering electrical cardioversion. Intravenous amiodarone may also convert atrial fibrillation and/or slow the ventricular response.[citation needed]
Surgery
The Canadian Cardiovascular Society (CCS) recommends surgical intervention for these indications:[12]
- Limited exercise capacity (NYHA III-IV)
- Increasing heart size (cardiothoracic ratio greater than 65%)
- Important cyanosis (resting oxygen saturation less than 90% - level B)
- Severe tricuspid regurgitation with symptoms
- Transient ischemic attack or stroke
The CCS further recommends patients who require operation for Ebstein's anomaly should be operated on by congenital heart surgeons who have substantial specific experience and success with this operation. Every effort should be made to preserve the native tricuspid valve.[12]
History
Ebstein's anomaly was named after Wilhelm Ebstein,[13][14] who in 1866 described the heart of the 19-year-old patient Joseph Prescher. Joseph Prescher was cyanotic with dyspnea, palpitations, jugular venous distension, and cardiomegaly. At autopsy, “Ebstein described an enlarged and fenestrated anterior leaflet of the tricuspid valve.” In addition, “the posterior and septal leaflets were hypoplastic, thickened, and adherent to the right ventricle. There was also a thinned and dilated atrialized portion of the right ventricle, an enlarged right atrium, and a patent foramen ovale.”[15]
References
- ISBN 978-3-030-24176-6.
- PMID 37344044.
- ^ "Facts About Critical Congenital Heart Defects | NCBDDD | CDC". www.cdc.gov. 2017-06-27. Retrieved 2017-10-12.
- PMID 17228014.
- S2CID 13187818.
- ISBN 978-93-5152-140-2.
- ^ "Atrioventricular Block". The Lecturio Medical Concept Library. Retrieved 3 July 2021.
- PMID 18056539.
- PMID 17228014.
- PMID 18982835. Archived from the originalon September 30, 2020.
- S2CID 252496690.
- ^ PMID 20352139.
- Who Named It?
- ^ W. Ebstein. Über einen sehr seltenen Fall von Insufficienz der Valvula tricuspidalis, bedingt durch eine angeborene hochgradige Missbildung derselben. Archiv für Anatomie, Physiologie und wissenschaftliche Medicin, Leipzig, 1866, 238-254.
- PMID 17228014.