Emergency Department Bedside Echocardiography in Diagnosis of Ebstein’s Anomaly with Wolff-Parkinson-White Syndrome and Atrial Fibrillation

Case Presentation: Heart Palpitations

A previously healthy 26-year-old Hispanic male presented to the emergency department with complaints of 2 days of vomiting and diarrhea, as well as worsening palpitations. Review of systems revealed that he also had fevers, sore throat and chest pressure. Vital signs were as follows: blood pressure 110/68, pulse 152 and irregular, oral temperature 36.7°C, oxygen saturation 100% and respiratory rate 20.

During the initial evaluation the emergency physician performed bedside echocardiography, which demonstrated obvious abnormalities of the right heart and the tricuspid valve (Figure 1). The tricuspid valve was displaced toward the apex and there was atrialization of the right ventricle. These findings are consistent with an undiagnosed Ebstein’s anomaly. Also, bubbles were seen within the left ventricle, the result of an atrial septal defect (ASD) and aggressive fluid resuscitation. An electrocardiogram revealed a wide-complex irregular tachycardia (Figure 2).

Figure 1.  Electrocardiogram (ECG).

Figure 2.  Atrialized left ventricle and atrial septal defect (ASD). LV = left ventricle; RV = right ventricle; RA = right atria; LA = left atria.

The patient was sedated with 20 mg of IV Etomidate and successfully cardioverted on the first attempt, using a 200 Joule synchronized biphasic shock. When he awoke from sedation his chest pressure had completely resolved. A repeat electrocardiogram revealed delta waves consistent with Wolf-Parkinson-White syndrome (Figure 3). The patient was admitted to the cardiology service and the initial echocardiographic findings were subsequently confirmed. He underwent successful radiofrequency ablation of multiple right atrial free wall accessory pathways. He continued to have dyspnea on exertion and subsequently had a stress echocardiogram which showed pulmonary hypertension and decreased right ventricular performance worsening with stress. It also showed a secundum ASD with increased right to left shunting with exercise. Evaluation for possible surgical repair of the ASD and the tricuspid valve is ongoing.

Figure 3.  Ebstein’s anomaly. RV = right ventricle; LV = left ventricle; RA = right atria; LA = left atria; ASD = atrial septal defect.

Ebstein′s anomaly, first described in 1866 by Wilhelm Ebstein, is a developmental defect of the tricuspid valve with atrialization of the right ventricle and abnormal formation of the tricuspid valve. This anomaly is anatomically defined with tricuspid septal leaflet displacement toward the apex of the heart. Associated abnormalities include displacement of the posterior leaflet toward the apex, elongation of the anterior leaflet, intracardiac shunts, as well as accessory conduction pathways in 5–10% of these patients. ASD or patent foramen ovalie is present in 90% of cases. Pulmonary stenosis or pulmonary atresia is present in 20–25%. These valvular abnormalities may cause significant tricuspid insufficiency and regurgitation resulting in congestive heart failure and requiring surgical intervention. Surgical intervention is usually attempted early, depending on the severity of regurgitation. The etiology of Ebstein’s anomaly remains unclear. It is associated with a history of previous maternal fetal loss. Environmental factors that have been implicated include maternal exposure to certain varnishing substances and maternal use of lithium or benzodiazepines.