Complications of Pulmonic Valve Endocarditis in Repaired Tetralogy of Fallot.

Transthoracic echocardiography plays a pivotal role in the diagnosis of complications, evaluation of hemodynamics, and management of patients with surgically repaired congenital heart disease. Late complications of surgically corrected tetralogy of Fallot (TOF), the most common cyanotic congenital heart disease, include pulmonary regurgitation (PR), ventricular septal defect (VSD) patch leakage, and residual right ventricular outflow tract obstruction. We present a case of severe PR secondary to Bartonella endocarditis in an adult with a history of repaired TOF in which echocardiography was instrumental in the diagnosis of severe PR, residual VSD, and a right-to-left shunt through an unsuspected patent foramen ovale. Copyright:

INTRODUCTION

Tetrology of Fallot (TOF) is the most common form of cyanotic congenital disease and has had marked improvement in outcomes over the last decades with advancements in medical and surgical repair. Nevertheless, TOF repair is still associated with a number of postsurgical complications for which there needs to be a low threshold of suspicion for evaluation.

CASE REPORT

A 49-year-old Peruvian-American female with repaired tetralogy of Fallot (TOF) presented to the hospital with a history of several weeks of generalized abdominal discomfort, fatigue, fever, and exertional dyspnea. Her initial surgery was at the age of 21 months and included ventricular septal defect (VSD) closure with a patch and right ventricular outflow tract (RVOT) reconstruction. Subsequently, at age 44, she had pulmonary valve replacement with a pulmonary homograft for severe pulmonary regurgitation (PR), tricuspid annuloplasty for moderate tricuspid regurgitation, and closure of a residual VSD. Previous echocardiograms performed at regular intervals after her surgery demonstrated no PR and only mild right ventricular dilatation.

Her examination on admission revealed prominent neck vein distention with Kussmaul's sign, a grade 2/6 early peaking systolic murmur with a short-grade 2/6 diastolic murmur at the left upper sternal border and a parasternal lift. The patient walked 20 yards and desaturated from 91% at rest to 78% with exercise. Echocardiography demonstrated increased right ventricular chamber size with the prominent paradoxical septal motion of the interventricular septum [Video 1]. Large irregular mobile masses were attached to the upstream ventricular side of the pulmonic valve, and one cusp was flail [Video 2]. M-mode view of the pulmonic valve showed a valve that was highly echogenic and thickened [Figure 1]. Color and spectral Doppler showed evidence of severe pulmonic regurgitation (PR) [Video 3 and Figure 2].

Figure 1

Transthoracic high parasternal long-axis M-mode view of the pulmonary valve showing highly echogenic, marked “thickenings”

Figure 2

Continuous-wave Doppler of pulmonary regurgitation showing rapid downslope of regurgitant jet with a pressure halftime of 90 ms and cessation of regurgitation at 70% of diastole. Equalization of pulmonary artery and right ventricular pressures before the end of diastole due to the large volume of blood flowing back into the right ventricular leads to early jet termination in severe pulmonary regurgitation, and this is a characteristic feature on continuous-wave Doppler that differentiates it from moderate pulmonary regurgitation

Travel history was notable for a visit to her birthplace in Peru 3 months before her presentation. Transesophageal echocardiography confirmed the highly mobile vegetations on the pulmonic valve [Video 4], with the morphology of the pulmonic valve once again appeared thickened with a gray scale similar to the myocardium, along with the presence of a hyperkinetic flail valve. In addition, color Doppler interrogation of the interatrial septum demonstrated a bidirectional shunt through a patent foramen ovale ([PFO] – Video 5 shows right-to-left shunt). A residual VSD with a small left-to-right shunt was found at the patch site [Video 6].

Although blood cultures were negative, Bartonella quintana IgG titers (>1:128) and IgM titers (>1:20) were elevated. She was started on a course of ceftriaxone and doxycycline for the treatment of Bartonella endocarditis. She underwent surgical replacement of the pulmonary valve with a 27-mm Medtronic Freestyle conduit and closure of the residual VSD and PFO. Pathology of the valve revealed an infected homograft. The patient had an improvement in functional capacity postsurgery, and she currently remains New York Heart Association Class I to II, with no desaturation with exercise.

DISCUSSION

Teaching points of this case include causes of pulmonary masses, the importance of echocardiographic imaging of the pulmonic valve in patient's status post-TOF repair, assessment of the severity of PR, determination of causes of desaturation with exercise, the presence of a residual VSD, and the diagnosis and treatment of Bartonella endocarditis.

Etiologies of pulmonic masses include infective endocarditis, Lambl's excrescences, papillary fibroelastoma, metastatic tumor, carcinoid, thrombus, and sonographic artifact.[123] Pulmonary valve endocarditis is uncommon, occurring in <1.5%–2.0% of patients diagnosed with infective endocarditis.[4] In this case, the appearance and large size of the masses help distinguish vegetation from degenerative excrescence, papillary fibroelastoma, and thickening due to carcinoid. The relative echogenicity of the masses suggests a subacute infectious process.

Evaluation of the pulmonic valve in patients with repaired TOF is crucial as PR is often a late complication, even without infective endocarditis. The standard parasternal short-axis view at the base can be supplemented with a laterally angulated long-axis view. The evaluation of the severity of PR is not as well validated as it is with aortic regurgitation, but several principles can be used to establish severe PR. Severe PR can be identified by a regurgitant jet that is >50% of the annular diameter.[5] Diastolic reversal of flow in the main pulmonary has a 92% sensitivity for severe PR.[6] In addition, there is cessation of the jet before the end of diastole due to rapid equalization of the pulmonary artery and right ventricle pressures due to the large volume of blood flowing back into the RVOT (which manifested on physical examination with the shorter duration of the murmur). Figure 2 shows continuous-wave Doppler of PR with rapid downslope of the regurgitant jet with pressure halftime of 90 ms and cessation of regurgitation at 70% of diastole. Both of these measures have been shown to correlate well with severe PR.[57]

The patient's desaturation with exercise raised suspicion for the development of a significant right-to-left shunt with exertion because of a prominent increase in pulmonary pressure and right atrial pressure with exercise. A significant right-to-left shunting through a PFO later in adulthood has been described in disorders causing increased right heart pressures.

Interestingly, this patient also had a residual VSD in spite of having a previous surgery for the closure of a patch leak. This is not an uncommon evolution of surgically corrected TOF, as residual VSD has been reported in about 9% of patients who have undergone TOF repair.[8]

The majority of cases of Bartonella endocarditis are caused by either Bartonella quintana or Bartonella henselae. As blood cultures are often negative, the diagnosis requires a high threshold of suspicion, and serologic testing and direct polymerase chain reaction assays are beneficial. Antibiotic regimens include tetracyclines for long-term therapy, with a bactericidal antibiotic such as an aminoglycoside during the first few weeks of therapy.[9] Per guidelines, therapy is recommended to be 4–6 weeks for native valve endocarditis and a total of 6 weeks for prosthetic valve endocarditis.[10] In our case, with the flail valve, surgical intervention was necessary.

CONCLUSION

Echocardiography plays a pivotal role in the diagnosis of complications and management of the pulmonic valve and patients with surgically repaired TOF. PR is a common late complication which is usually caused by valve degeneration. This case demonstrates that endocarditis, though rare, should be considered as an etiology of severe PR in repaired TOF.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

This article was financially supported by the Strategic Research Institute of Indiana University School of Medicine, Indianapolis, IN, USA.

Conflicts of interest

There are no conflicts of interest.