Age: 33 years
Gender: Male
Occupation: Accountant
Working diagnosis: Ebstein malformation, previous artial septal defect repair
HISTORY
The patient was found to have a murmur at age 6, which led to the diagnosis of an ASD with Ebstein malformation of the tricuspid valve. At age 7 he underwent surgical closure of the ASD. He had a normal recovery, but after age 15 had no further cardiologic follow-up. He reports feeling well during those years.
At the age of 32, he experienced palpitations. He was hospitalized at an outside institution with fast atrial fibrillation. He was started on amiodarone and his rate was controlled. He was also found to have abnormal liver function tests at that time. An echocardiogram showed severe Ebstein anomaly of the tricuspid valve with severe tricuspid regurgitation. He underwent a liver biopsy to clarify the etiology of the liver enzyme abnormalities. He was referred for possible heart transplantation.
Comments: About half of all patients with Ebstein anomaly have an ASD or a stretched patent foramen ovale. These are the Ebstein patients who are cyanotic at rest or perhaps become cyanotic only with exertion. As a rule, the cyanotic patient with Ebstein anomaly should not have the ASD closed. A minority of these patients, such as this patient, benefit from ASD closure either to eliminate a large left-to-right shunt or to prevent exertional desaturation causing exercise intolerance.
Atrial flutter, less commonly atrial fibrillation, is common in Ebstein anomaly when the RA is very large. Such arrhythmias may be poorly tolerated and should be carefully treated. If recurrent, an ablative procedure or even cardiac surgery may be required.
CURRENT SYMPTOMS
The patient is short of breath with moderate exertion, such as walking uphill. However, he still does low-intensity aerobic workouts, such as cycling, on a regular basis.
He denies any lightheadedness, dizziness, or syncope.
He is a nonsmoker and drinks alcohol on rare social occasions.
NYHA class: II
PHYSICAL EXAMINATION
BP 112/76 mm Hg, HR 70 bpm, oxygen saturation 98%
Height 178 cm, weight 61 kg, BSA 1.74 m 2
Surgical scars: Median sternotomy scar
Neck veins: Visible neck veins 8 cm above the sternal angle, with a dominant V-wave and Y descent
Lungs/chest: Clear
Heart: Irregular rhythm. Right ventricular lift. Split S1 with a loud tricuspid component. Normal S2. Grade 2/6 systolic murmur at the lower left parasternal edge, which did not increase with inspiration. No diastolic murmurs. Normal peripheral pulses.
Abdomen: Moderate hepatomegaly with soft, nontender, pulsatile liver
Extremities: No edema
Comments: Even though the systolic murmur seems to be due to tricuspid regurgitation, it did not increase on inspiration. This may be due to RV impairment, such that the RV cannot increase its stroke volume despite increased RV preload.
A V-wave is typically not visible at the level of the neck veins due to low-pressure tricuspid regurgitation and a large, compliant RA. This patient is an exception to this rule.
The split first heart sound with loud tricuspid component is called the “sail sign.” It occurs because the large, sail-like anterior tricuspid leaflet takes more time to reach the closed position.
LABORATORY DATA
| Hemoglobin | 14.9 g/dL (13.0–17.0) |
| PCV | 46% (41–51) |
| MCV | 94 fL (83–99) |
| Platelet count | 91 × 10 9 /L (150–400) |
| WBC | 6 × 10 9 /L (3.6–9.2) |
| Sodium | 140 mmol/L (134–145) |
| Potassium | 4.2 mmol/L (3.5–5.2) |
| Creatinine | 0.92 mg/dL (0.6–1.2) |
| Blood urea nitrogen | 5.2 mmol/L (2.5–6.5) |
| Total bilirubin | 29 μmol/L (3–24) |
| ALP | 82 U/L (38–126) |
| ALT | 19 U/L (8–40) |
| Total protein | 70 g/L (62–82) |
| Albumin | 41 g/L (37–53) |
OTHER RELEVANT LAB RESULTS
Liver biopsy: Some hepatocyte replacement with fibrosis, indicative of early cirrhosis.
Comments: Total bilirubin was mildly elevated, but the remaining liver function parameters were within normal limits. The abnormal liver enzymes reported at the other facility may have been due to raised right-sided pressure at the time of rapid atrial fibrillation.
ELECTROCARDIOGRAM
FINDINGS
Heart rate: 70 bpm
QRS axis: Right-axis deviation of initial forces
QRS duration: 136 msec
Atrial fibrillation. Right-axis deviation of initial forces with terminal, complete RBBB.
Comments: Arrhythmias are a common reason for adults with Ebstein anomaly to come to medical attention. Atrial flutter, atrial fibrillation, and reentrant tachycardias related to accessory pathways may be encountered.
A Q-wave in the V1 lead is characteristic of Ebstein anomaly. This is due to the large RA and leftward rotation of the heart causing V1 to record RV intracavitary potentials. For the same reason V1 may resemble the aVR lead.
CHEST X-RAY
FINDINGS
Cardiothoracic ratio: 63%
Situs solitus, levocardia, left aortic arch. Very large cardiac silhouette. The RVOT and/or main pulmonary artery were prominent. Pulmonary blood flow seemed normal or diminished.
Comments: The cardiothoracic ratio may range from normal to grossly enlarged in patients with Ebstein anomaly. If increased, as is usual, the dilation is due to enlarged right heart chambers. Pulmonary blood flow is normal or decreased unless there is a sizable left-to-right shunt through an ASD, which may cause increased pulmonary vascular markings. The aortic arch or knuckle is typically small due to a chronically low cardiac output.
EXERCISE TESTING
| Exercise protocol: | Modified Bruce |
|---|---|
| Duration (min:sec): | 10:38 |
| Reason for stopping: | Dyspnea |
| ECG changes: | Atrial fibrillation throughout |
| Rest | Peak | |
|---|---|---|
| Heart rate (bpm): | 70 | 151 |
| Percent of age-predicted max HR: | 81 | |
| O 2 saturation (%): | 98 | 98 |
| Blood pressure (mm Hg): | 112/76 | 145/80 |
| Peak V o 2 (mL/kg/min): | 23 | |
| Percent predicted (%): | 67 | |
| VE/V co 2 : | 26 | |
| Metabolic equivalents: | 6.5 |
Comments: The patient’s exercise tolerance was surprisingly good (67% of predicted) and well above the recommended level for consideration of heart transplantation in patients with LV dysfunction (14 mL/kg/min). The test results are consistent with the patient’s self-reported exercise tolerance and his regular exercise routine. He has a good chronotropic response despite atrial fibrillation.
The Ve/V co 2 slope is a measure of ventilatory efficiency. Ventilation–perfusion mismatch and enhanced ventilatory reflex sensitivity are thought to be the major determinants of the Ve/V co 2 slope. Recently, a Ve/V co 2 slope of 38 or above was identified as a marker of adverse outcome in noncyanotic adults with congenital heart disease.
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