Age: 36
Gender: Female
Occupation: Office clerk
Working diagnosis: Severe tricuspid valve regurgitation
HISTORY
The patient presented in early infancy with dyspnea and failure to thrive. Cardiac catheterization and angiography showed a very large VSD with left-to-right shunting, and she underwent pulmonary artery (PA) banding at the age of 8 weeks. During her early childhood, the patient gradually became cyanotic but otherwise remained asymptomatic, and the decision to close the defect was postponed several times.
At age 14 she underwent surgical closure of the VSD with a Dacron patch and release of the PA band. Several of the chordae tendinae supporting the tricuspid valve ran through the defect and inserted on the LV side of the septum. The surgeon placed the patch around these insertions so as to minimize any tricuspid valve insufficiency.
Postoperatively, however, an echocardiogram showed severe tricuspid regurgitation, severe pulmonary stenosis, and a persistent VSD. Furthermore, the patient developed postoperative complete heart block. Endocardial pacing wires failed to capture, so an epicardial pacing system was placed. She also had postoperative paralysis of the right hemidiaphragm and a recurrent right pleural effusion, which eventually required a right pleurodesis.
In the ensuing years, the patient remained cyanotic. Her clinicians debated about the merits of further surgery. Her outpatient workup continued to show severe tricuspid regurgitation, pulmonary stenosis, and a VSD. A diagnostic catheterization was done to measure the PA pressures and was complicated by a right femoral venous thrombosis. She was started on warfarin.
The patient remained free of overt symptoms, and so surgery was avoided as long as possible. However, two isolated episodes of infective endocarditis in her late adolescent years, both treated successfully with antibiotics, made the tricuspid regurgitation even worse.
At age 25, she finally underwent repeat surgery. There was contraction and thickening of the septal leaflet of the tricuspid valve. A 10-mm VSD was closed, and a patch placed in the RVOT to widen the outflow. A tricuspid valve annuloplasty was also performed. Her epicardial pacemaker was replaced with an endovascular system, but the ventricular lead had to be placed in the RVOT for reliable capture.
The patient recovered from surgery without complications. A postoperative echocardiogram showed moderate tricuspid regurgitation with moderate RV dysfunction.
Medical management of her “failing RV” and tricuspid regurgitation continued, and the patient remained asymptomatic and able to work full time. Several years later she had an episode of sustained ventricular tachycardia (VT) requiring urgent cardioversion. An electrophysiologic study showed VT arising from a focus near the pacing wire in the RVOT. After catheter ablation, VT could no longer be induced.
At age 27 she again developed sustained VT in the setting of hyperkalemia and acute renal failure. This was likely related to overdiuresis. With fluid balance and correction of her electrolytes her renal function returned to normal. The patient was considered for tricuspid valve replacement (TVR) and RA maze, and admitted to the hospital for surgery. However, on further review the night before the procedure, and considering her relative lack of symptoms, the procedure was cancelled.
After 2 more years of follow-up, the patient began to note more marked exercise intolerance. A repeat workup included a nuclear angiogram; her RVEF was 27%. After group discussion, it was felt her TR was secondary to her RV failure, and a conservative approach was again elected.
Over the next 2 years the patient continued to deteriorate clinically. She had several hospital admissions for right-sided heart failure and/or renal dysfunction.
Eventually, she had to stop working as a bank clerk. Because of her worsening clinical status, her case was again reviewed with consideration of repeat surgery.
Comments: PA banding has been used to protect infants with large or multiple VSDs or otherwise complex anatomy to reduce pulmonary blood flow and pressures and thus prevent pulmonary vascular disease.
Chordal insertion from an AV valve through a VSD to the contralateral septum or free wall, as was later found here, is known as valve “straddling.” Valve straddling poses a major challenge to the surgeon, in that it makes closure of the VSD difficult, if not impossible, without affecting the function of the AV valve. It is unclear as to whether the straddling was fully appreciated before surgery. Nevertheless, VSD closure was associated with severe dysfunction of the tricuspid valve immediately after surgery. In addition, sutures placed near the conduction system can result in heart block, as occurred in this patient. Removal of the PA band may leave residual obstruction; the RVOT obstruction was fortuitous in her case, as a residual, moderate-sized VSD was present at the end of the operation.
In a patient in whom the first operation was complicated and unsuccessful, further surgery is daunting both for the patient and family as well as the surgeon. The pulmonary stenosis was preventing pulmonary vascular disease from developing as a result of her persistent VSD. Yet pulmonary stenosis also worsened the tricuspid valve regurgitation by causing elevated RV pressures. The delay and difficult decision making in this case are easy to understand.
The venous thrombosis, endocarditis, and problems with pacing are complications that arise both as a result of inherent congenital abnormalities and as iatrogenic complications, both seen in this patient.
Contraction and shrinking of the leaflets were felt to be related both to prior endocarditis and to previous repair. The chordal structures that initially straddled the VSD were no longer intact.
The patient is now no longer cyanotic, but still has tricuspid valve insufficiency and impaired RV function.
Sustained arrhythmias in patients with ACHD often reflect or coexist with severe hemodynamic problems, as in this patient. It is a good rule of thumb to consider each arrhythmia as a reminder to look for correctable hemodynamic problems.
The decision not to operate reflected the patient’s lack of symptoms and concern that the high risks of further tricuspid surgery might not be rewarded by clinical improvement.
It can be difficult to determine whether tricuspid insufficiency is entirely due to RV dilation and dysfunction, or vice versa.
This patient had continued to work despite several years of medical problems for which disability would have been an easy option. She is a good example of many congenital heart patients who continue to live their lives as fully as possible despite worsening problems and physical disability. It is a testament to their stamina and stoicism. Furthermore, the fact that she now feels incapable of continuing to do so is a sign of how much worse she has become.
CURRENT MEDICATIONS
Enalapril 10 mg twice daily
Furosemide 80 mg mornings, 40 mg evenings
Spironolactone 50 mg twice daily
Amiodarone 200 mg daily
Warfarin adjusted dose to maintain an INR of 2.0–3.0
Comments: Her medical regimen was being adjusted according to her symptoms, weight, neck veins, and creatinine levels.
Amiodarone had been given after the patient’s episode of VT, although, arguably, her risk for VT was probably low after successful ablation, due because her second episode of VT was metabolic in origin.
PHYSICAL EXAMINATION
BP 100/60, HR 80 (paced), oxygen saturation 94%
Height 156 cm, weight 63 kg, BSA 1.63 m 2
Surgical scars: Median sternotomy scar
Neck veins: The JVP was seen at 7 cm above sternal angle, with large V waves.
Lungs/chest: Clear to auscultation, but breath sounds were absent at the right base.
Heart: Regular rhythm with a persistently split second heart sound. There was a grade 2/6 holosystolic murmur at the left lower sternal border, increasing in inspiration. A right ventricular lift was not appreciated. The left ventricular apex beat was normal.
Abdomen: The liver was palpable just 1 cm beyond the costal margin. No ascites was present.
Extremities: There was 3+ bilateral pitting edema to above the knees.
Comments: Signs of right heart failure are present despite medical therapy.
The murmur is consistent with tricuspid regurgitation, which may become less audible as it becomes more severe. Such a murmur will increase on inspiration in about half of patients with substantial tricuspid regurgitation.
LABORATORY DATA
| Hemoglobin | 13.2 g/dL (11.5–15.0) |
| Hematocrit/PCV | 39% (36–46) |
| MCV | 92 fL (83–99) |
| Platelet count | 234 × 10 9 /L (150–400) |
| Sodium | 134 mmol/L (134–145) |
| Potassium | 3.6 mmol/L (3.5–5.2) |
| Creatinine | 0.94 mg/dL (0.6–1.2) |
| Blood urea nitrogen | 4.2 mmol/L (2.5–6.5) |
OTHER RELEVANT LAB RESULTS
Prior creatinine had been as high as 3.2 mg/dL. Liver function tests were normal.
Comments: Her renal function at this time is normal, although she has had labile creatinine levels dependent on intravascular volume status.
ELECTROCARDIOGRAM
FINDINGS
Heart rate: 75 bpm (paced)
AV sequential pacing
FINDINGS
Regular, wide QRS complex tachycardia at a rate of 160
LBBB conduction pattern, suggesting an RV origin.
Comments: This ECG was obtained at the time of a prior hospitalization. The rhythm is VT. An electrophysiologic study showed a similar rhythm inducible in the RVOT near the existing pacing wire (see Fig. 10-3 ). Following successful catheter ablation, the VT could no longer be induced.
CHEST X-RAY
FINDINGS
Cardiothoracic ratio: 70%
There was a prior sternotomy. There was also gross cardiomegaly with marked RA enlargement. An epicardial pacing lead near the LV apex was seen. A transvenous pacing system was present with two leads in the RA and one in the RVOT. The pulmonary arteries were normal, and the lung fields had a normal vascular pattern. There was no LA enlargement. There was an opacity at the right lung base, seen on prior films.
Comments: The aftermath of complications from her first surgery are visible, namely the elevated right hemidiaphragm from a phrenic nerve palsy and epicardial pacing wires. The ventricular lead in the RVOT was the site of prior VT (see the section “ History ”). Cardiomegaly here is largely secondary to RA enlargement.
EXERCISE TESTING
| Exercise protocol: | Modified Bruce |
|---|---|
| Duration (min : sec): | 6 : 27 |
| Reason for stopping: | Dyspnea |
| ECG changes: | Paced |
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