Age: 31 years
Gender: Female
Occupation: Teacher
Working diagnosis: Tetralogy of Fallot
HISTORY
The patient was diagnosed at birth with TOF. At age 3 (1976) primary repair was performed, with reconstruction of the RVOT with a transannular pericardial patch.
Although she was asymptomatic, serial echocardiograms showed progressive pulmonary regurgitation, which was noted to be mild when she was 11 years old, moderate by age 27, and severe by age 30.
Otherwise, the patient noted only occasional symptoms of palpitations, which were described as “missed beats,” or a few seconds of awareness of her heartbeat.
In the last 18 months she noted a more noticeable “slowing down” in her usual activities, as well as occasional episodes of fast, regular palpitations lasting 30 seconds at a time.
Comments: Transannular patching (whereby the annulus of the pulmonary valve is incised and hence disrupted) is necessary when the pulmonary valve and artery are very small; in this case they were perioperatively described as being a quarter of the size of the aorta, whereas typically they are very similar in size. The surgical approach to repair of tetralogy has evolved over the years. Early cohorts underwent repair through a right ventriculotomy, whereas now repair through the RA and pulmonary artery is the norm. In this patient, the pulmonary annulus was sufficiently restrictive to necessitate the use of a transannular patch for complete relief of the RVOT obstruction, which created the potential for free pulmonary regurgitation.
In the modern era, it has become apparent that there are detrimental long-term effects of right ventriculotomy and chronic pulmonary regurgitation on RV function, the propensity to arrhythmia, and sudden cardiac death. Current surgery uses a combined transatrial/transpulmonary approach allowing both closure of the VSD and relief of the RVOT obstruction to be carried out from the right atrium and the pulmonary artery. If there is no disruption of the pulmonary valve annulus, any subvalvular patch is termed an RVOT patch.
CURRENT SYMPTOMS
Although noting reduced exertional stamina compared to prior years, the patient was able to work full time and did not experience breathlessness in her usual activities. There were no specific symptoms of chest pain, syncope, or breathlessness on exertion.
NYHA class: I
Comments: It may be that in the context of pulmonary regurgitation late after repair of TOF, waiting for the patient to become clearly symptomatic may risk deferring pulmonary valve surgery too long.
PHYSICAL EXAMINATION
BP 110/70 mm Hg, HR 70 bpm, oxygen saturation 100%
Height 158 cm, weight 86 kg, BSA 1.94 m 2
Surgical scars: Midline sternotomy scar
Neck veins: Normal JVP was seen.
Lungs/chest: Clear to auscultation
Heart: The heart rate was regular. There was an RV heave. Auscultation revealed a normal first heart sound, a systolic ejection murmur at the left upper sternal border, and a short early diastolic murmur at the left sternal edge. There was a single second heart sound. Peripheral pulses were palpable and equal.
Abdomen: No abnormality detected
Extremities: No abnormality detected
Comments: An RV lift or heave in such a patient is due to RV pressure or volume overload. Volume overload is much more common, and usually associated with severe pulmonary regurgitation and possibly tricuspid regurgitation. Pressure overload would be due to RV outflow or pulmonary arterial obstruction, or pulmonary hypertension.
The murmur of low-pressure pulmonary regurgitation is usually 2+ and seldom 3+ in intensity. Augmentation by inspiration is worth looking for. When pulmonary regurgitation is severe, the murmur may be minimal or even absent. The systolic ejection type murmur is due to increased flow through the valve during systole. A more harsh systolic murmur may indicate residual stenosis in the RVOT. The single second heart sound is the aortic component because in repaired TOF there is often no audible closure of the pulmonary valve.
LABORATORY DATA
| Hemoglobin | 13.7 g/dL (11.5–15.0) |
| Hematocrit/PCV | 39% (36–46) |
| MCV | 86 fL (83–99) |
| Platelet count | 242 × 10 9 /L (150–400) |
| Sodium | 139 mmol/L (134–145) |
| Potassium | 4.1 mmol/L (3.5–5.2) |
| Creatinine | 0.75 mg/dL (0.6–1.2) |
| Blood urea nitrogen | 3.3 mmol/L (2.5–6.5) |
Comments: No abnormalities detected.
ELECTROCARDIOGRAM
FINDINGS
Heart rate: 64 bpm
QRS axis: +117°
QRS duration: 138 msec
Normal sinus rhythm with RBBB.
24-hour ECG recording: Rare supraventricular and ventricular ectopics, no arrhythmia, no ECG abnormalities were seen at the time of reported symptoms of palpitations.
Comments: RBBB pattern is almost universal in patients who have undergone a right ventriculotomy.
CHEST X-RAY
FINDINGS
Cardiothoracic ratio: 53%
Right aortic arch. The appearance of the left heart border suggests a dilated RVOT.
Comments: Right aortic arch, defined by the position of the arch in relation to the trachea, is commonly associated with TOF and may be seen in up to 30% of patients. When right aortic arch is associated with other anomalies of the aortic arch vessels, the probability of 22q11 microdeletion is high.
EXERCISE TESTING
| Exercise protocol: | Modified Bruce |
|---|---|
| Duration (min:sec): | 9:30 |
| Reason for stopping: | Dyspnea |
| ECG changes: | None |
| Rest | Peak | |
|---|---|---|
| Heart rate (bpm): | 70 | 166 |
| Percent of age-predicted max HR: | 88 | |
| O 2 saturation (%): | 100 | 100 |
| Blood pressure (mm Hg): | 110/70 | 140/80 |
| Peak V o 2 (mL/kg/min): | 18.8 | |
| Percent predicted (%): | 48 | |
| Ve/V co 2 : | 34.8 | |
| Metabolic equivalents: | 7.8 | |
Comments: In our institution this V o 2 in absolute terms is below the mean for repaired TOF with pulmonary regurgitation. (Out of 92 prospectively studied repaired TOF patients with pulmonary regurgitation who reached a respiratory quotient [RQ] greater than 1, the mean peak V o 2 obtained was 25.6 ± 7.8 mL/kg/min and the mean Ve/V co 2 slope was 30.3 ± 8.3.)
ECHOCARDIOGRAM
OVERALL FINDINGS
The RV was severely dilated but had normal function. LV function was normal.
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