Patent foramen ovale complicating heart transplantation. A window on posttransplantation hemodynamics

Donor heart selection: Evidence-based guidelines for providers

The proposed donor heart selection guidelines provide evidence-based and expert-consensus recommendations for the selection of donor hearts following brain death. These recommendations were compiled by an international panel of experts based on an extensive literature review.

Patent foramen ovale diagnosis: The importance of provocative maneuvers

Patent foramen ovale (PFO) is a frequent congenital anomaly, but massive right-to-left shunt (RTLS) is normally prevented by higher pressures in left heart chambers. However, mechanical ventilation with positive end-expiratory pressure (PEEP) can significantly increase right atrial pressure, accentuating the RTLS, mainly after major cardiothoracic surgery. We report a patient admitted to the intensive care unit after cardiac surgery. Pre- and intraoperative transesophageal echocardiography only described an aneurysmal interatrial septum with no shunt. However, high-PEEP ventilation induced a paradoxical response with life-threatening hypoxemia, triggering further echocardiographic evaluation, revealing massive RTLS across a stretch PFO. Provocative maneuvers (Valsalva/PEEP) significantly increase echocardiographic sensitivity, unmasking silent PFO. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:58-61, 2017.

[Perioperative implications of heart transplant]

Over the past 30 years, heart transplantation has evolved into a definitive therapy for patients with end-stage cardiomyopathy. However, perioperative management of patients undergoing heart transplantation remains a challenge for anesthesiologists. The presence of biventricular failure, arrhythmias and associated multisystem organ dysfunction may contribute to significant intraoperative hemodynamic instability prior to the initiation of cardiopulmonary bypass (CPB). Even after an uneventful transplantation, weaning from CPB may be difficult. Acute right ventricular failure can develop in the recipient secondary to pre-existing pulmonary hypertension. Treatment options frequently focus on therapeutic interventions directed towards decreasing pulmonary vascular resistance and improving right ventricular contractility. Intraoperative use of transesophageal echocardiography (TEE) enables the anesthesiologist to diagnose acute right ventricular failure early on and guide therapy. Concurrent pathology including kinking of the pulmonary artery anastomosis or valvular insufficiency in the transplanted heart can also be recognized and addressed. The number of patients undergoing cardiac transplantation is continually increasing. In addition, the use of more effective immunosuppressive agents has curtailed transplant rejection and permitted longer survival. Consequently, heart transplant recipients are more frequently presenting for non-cardiac surgical procedures. Thus, an understanding of physiological and pharmacological implications associated with heart transplantation is crucial for managing these patients in the perioperative period.

Transcatheter closure of residual atrial septal defect after cardiac transplantation

A 55-year-old male patient experienced 2 acute neurologic events 3 weeks after orthotopic cardiac transplantation. Transesophageal echocardiography demonstrated a patent foramen ovale in the native portion of the interatrial septum with bidirectional shunting by Doppler and microbubble contrast. The defect was closed successfully with a CardioSeal transcatheter septal closure device. This case demonstrates the advantages of the percutaneous approach for closure of residual defects in the post-operative patient.

[Patent foramen oval as a cause of severe hypoxia during the immediate postoperative period following heart transplantation]

We report the case of a 44-year-old man with dilated cardiomyocardiopathy, pulmonary hypertension and high pulmonary resistance who underwent orthotopic heart transplant. Following transplantation severe hypoxia was observed after weaning of cardiopulmonary bypass secondary to a patent foramen oval in the donor heart. This situation does not usually lead to problems in the donor, however taking into account the special hemodynamic conditions of the transplanted patient, with high pressure in the right side, an opening occurred producing a significant right-left shunt causing severe receptor hypoxia. Successful closure of the patent foramen oval was performed.

Patent foramen ovale presenting as refractory hypoxemia after heart transplantation

Hypoxemia can be an early life-threatening complication of orthotopic heart transplantation. Commonly, hypoxemia after orthotopic heart transplantation is due to pulmonary hypertension or pulmonary complications. Rarely, structural defects either in the donor or recipient heart can lead to life-threatening hypoxemia. This case illustrates hypoxemia after orthotopic heart transplantation caused by the development of a right-to-left shunt through a patent foramen ovale in the recipient which had preoperatively been hemodynamically insignificant. The refractory hypoxemia required emergency surgical correction of the patent foramen ovale within the first postoperative week. In addition, this case illustrates the unique application of different methods of echocardiograms providing noninvasive diagnosis of structural defects in orthotopic heart transplantation.

Closure of a patent foramen ovale and tricuspid valve replacement after heart transplantation

Patent foramen ovale has been noted after cardiac transplantation. Rarely is surgical intervention warranted. In this communication we report a case of severe tricuspid regurgitation and paradoxical embolism secondary to a patent foramen ovale in a patient 19 months after heart transplantation. The patient underwent successful closure of the patent foramen ovale and tricuspid valve replacement.

Enhancement of hypoxemia by right-to-left atrial shunting in severe asthma

We report two cases of severe hypoxemia due to right-to-left shunt in acute asthmatic patients. During acute asthma, the transmural right atrial pressure can be higher than left atrial pressure during inspiration and then induce a right-to-left shunt through inter-atrial communication leading to hypoxemia. Contrast echography as well as Doppler analysis can easily confirm the diagnosis.

Transcatheter closure of residual atrial septal defect following cardiac transplantation

An almost 3-year-old boy had a residual atrial septal defect after cardiac transplantation. The patient was symptomatic and had arrhythmia and cardiac enlargement. An atrial septal defect occlusion device was employed to close the communication with excellent results. Transcatheter occlusion enabled the patient to avoid further surgery and did not interfere with follow-up endomyocardial biopsies.

Respiratory complications of cardiac transplantation

The authors evaluated all respiratory complications of cardiac transplantation in a 10-year study of 94 consecutive recipients. Mean follow-up time was 20 +/- 17 months. The initial 20 patients were treated with azathioprine and prednisone, while the subsequent 74 patients received cyclosporine and prednisone. In the azathioprine group, respiratory infections accounted for 24 of 60 (40%) infections. Two-thirds of the respiratory infections occurred in the first 3 postoperative months and were generally localized processes (focal pneumonitis, nodule(s), abscess, or empyema). Gram-positive and gram-negative bacteria (8/30) and aspergillus (8/30) were the predominant pathogens. Respiratory failure occurred in 29% of infectious episodes. In the cyclosporine group, there were significantly fewer respiratory infections. There was also a reduction in the number of nonrespiratory infections; hence, the percentage of total infections due to respiratory causes, 26 of 50 (52%), was not significantly different. In contrast, however, nearly two-thirds of the respiratory infections in cyclosporine-treated patients occurred after the first 3 postoperative months, and were usually diffuse processes. Despite diffuse disease, respiratory failure was observed with similar frequency (19%). Pneumocystis carinii (9/31) and cytomegalovirus (CMV) (7/31) were the predominant pathogens. CMV pneumonitis tended to occur earlier than that due to P. carinii (2.9 +/- 1.9 mo vs. 9.8 +/- 11.2 mo, respectively), but there was considerable overlap. In comparison with infectious processes, there were 50% fewer noninfectious respiratory complications in both groups. These were primarily pleural (46%) or thromboembolic (18%) disorders. Four of five pulmonary emboli occurred in patients with intercurrent cardiorespiratory illness, and were detected only at autopsy. The authors conclude that respiratory infections account for one-half of all infections observed in cardiac transplant recipients, despite the reduced infection rate associated with the use of cyclosporine. Furthermore, respiratory infections in cyclosporine-treated patients exhibit different clinical and etiologic features than those seen in azathioprine-treated patients. Finally, occult thromboemboli may be difficult to recognize in cardiac transplant recipients because of the high incidence of coexisting cardiorespiratory disease.