Permanent pacing in Ebstein's anomaly

Distal His bundle pacing in a patient with surgically corrected complex Ebstein anomaly and symptomatic second-degree atrioventricular block: a case report

Background

Ebstein's anomaly occurs when there is an apical displacement of the tricuspid valve with septal and posterior valve leaflets tethering. This condition often occurs in association with other congenital, structural, or conduction system diseases, including intracardiac shunts, valvular lesions, arrhythmias, accessory conduction pathways, and first-degree atrioventricular (AV) block. We present for the first time a case of a patient with Ebstein's anomaly who presented with second-degree Mobitz II AV block and was successfully treated with conduction system pacing (CSP) due to her young age and the likelihood of a long-term high percentage of pacing.

Case summary

We present a case of a 42-year-old lady with a background of complex congenital heart disease, including severe pulmonary stenosis, Ebstein anomaly, and atrial septal defect (ASD). She required complex surgical intervention, including tricuspid valve (TV) repair and subsequently replacement, ASD closure, and pulmonary balloon valvuloplasty. She presented to our hospital with symptomatic second-degree Mobitz II AV block (dizziness, shortness of breath, and exercise intolerance) and right bundle branch block (RBBB) on her baseline ECG. Her echocardiogram showed dilated right ventricle (RV) and left ventricle (LV) with low normal LV systolic function. Due to her young age and the likelihood of a long-term high percentage of RV pacing, we opted for CSP after a detailed discussion and patient consent. The distal HIS position is the preferred pacing strategy at our centre. We could not cross the TV with the standard Medtronic C315 HIS catheter, so we had to use the deflectable C304 HIS catheter. Mapping and pacing of the distal HIS bundle were achieved by Medtronic Selectsecure 3830, 69 cm lead. HIS bundle pacing led to the correction of both second-degree Mobitz II AV block and pre-existing RBBB. The implantation was uneventful, and the patient was discharged home the next day without any acute complications.

Discussion

Distal HIS pacing is feasible in patients with surgically treated complex Ebstein anomaly and heart block. This approach can normalize the QRS complex with a high probability of preserving or improving LV function.

A multidisciplinary approach to re-intervention in an Ebstein patient: a case report

Background

Ebstein's anomaly is a rare condition due to incomplete delamination of the tricuspid valve (TV) leaflets with downward displacement of the proximal leaflet attachments. It is associated with a smaller functional right ventricle (RV) and tricuspid regurgitation (TR) that is typically treated with TV replacement or repair. However, future re-intervention poses challenges. We describe a multidisciplinary team approach to re-intervention in a pacing-dependant Ebstein patient with severe bioprosthetic TV regurgitation.

Case summary

A 49-year-old female patient underwent bioprosthetic TV replacement for severe TR in Ebstein's. Post-operatively, she developed complete atrioventricular (AV) block necessitating the implantation of a permanent pacemaker which included a coronary sinus (CS) lead as the ventricular lead. Five years later, she presented with syncope due to a failing ventricular pacing lead, and a new RV lead was positioned across the TV bioprosthesis due to the lack of CS options. Two years later, she presented with breathlessness and lethargy with severe TR identified on transthoracic echocardiography. She successfully underwent a percutaneous leadless pacemaker implant, extraction of existing pacing system, and implantation of valve-in-valve TV.

Discussion

Patients with Ebstein's anomaly typically undergo TV repair or replacement. Following surgical intervention, owing to the anatomical location, patients can develop AV block requiring a pacemaker. Pacemaker implantation may involve a CS lead to avoid placing a lead across the new TV in efforts to avoid lead induced TR. Over time, these patients not uncommonly require re-intervention that can be challenging especially in pacing-dependant patients with leads across the TV.

Cardiac Implantable Electronic Devices in Ebstein Anomaly: Management and Outcomes

BACKGROUND

Optimal management of cardiac implantable electronic devices (CIEDs) in patients with Ebstein anomaly during tricuspid valve (TV) surgery is unknown. Thus, we aimed to characterize CIED management/outcomes in patients with Ebstein anomaly undergoing TV surgery.

METHODS

Patients at the Mayo Clinic from 1987 to 2020 with Ebstein anomaly and CIED procedure were reviewed for procedural details, complications, echocardiogram, and lead parameters. Five-year cumulative incidence of CIED complications were estimated using the Kaplan-Meier method.

RESULTS

Ninety-three patients were included; 51 were female, and mean age was 40.7±17.5 years. A new CIED was implanted in 45 patients at the time of TV surgery with the majority receiving an epicardial (n=37) CIED. Among 34 patients who had preexisting CIED (11 epicardial, 23 transvenous) at time of TV surgery, 20 had a transvenous right ventricular lead managed by externalizing the lead to the TV (n=15) or extracting the transvenous lead with epicardial lead implantation (n=5). Fourteen patients underwent CIED implantation (4 epicardial, 10 transvenous) without concurrent surgery. Placement of lead across the TV was avoided in 85% of patients. The 5-year cumulative incidence of CIED complications was 24% with no significant difference between epicardial and transvenous CIEDs (26% versus 23%, P=0.96). Performance of lead parameters was similar in epicardial and transvenous leads during median (interquartile range) follow-up of 44.5 (61.1) months.

CONCLUSIONS

In patients with Ebstein anomaly undergoing TV surgery, the use of epicardial leads and externalization of transvenous leads to the TV can avoid lead placement across the valve leaflets. Lead performance and CIED complications was similar between epicardial and transvenous CIEDs.

Clinical Spectrum and Long-term Outcome of 183 Cases of Ebstein's Anomaly, Experience of Mexican Population

BACKGROUND

Ebstein's anomaly (EA) is a myopathy of the right ventricle that causes a variable spectrum of tricuspid valve delamination failure with diverse clinical and anatomical presentation. We reviewed our data of EA to establish an association between clinical and echocardiographic findings with mortality.

METHODS

We divided patients in infants, Children/adolescents (Ch/A), and adults, according to age of presentation. Clinical and echocardiographic parameters were compared among groups. Multivariate analysis was performed for mortality. Survival analysis was plotted using Kaplan Meier curves.

RESULTS

Cyanosis, severe forms of AE and heart failure were more frequent among infants, arrhythmias in Ch/A and stroke among adults. Surgery was performed in 71 patients; infants had higher mortality and early complications. We found that the predicted mortality at 40 years of age in the three groups was significantly different (log rank test, p <0.0001): Infants: 38%, Ch/A 16 and 4% in adults. Multivariate model in surgical group showed that progressive drop of right ventricular fractional shortening (RVFS) predicts a higher mortality risk. In the non-surgical group, low RVFS and cyanosis were significantly associated with mortality.

CONCLUSION

EA in infants is linked to higher morbidity and mortality, while arrhythmias predominate in Ch/A and stroke in adults. In general, stroke is frequent in patients with EA, some prevention alternative must be implemented. Right ventricular dysfunction is very important in EA and is associated with high mortality. It must be subject of discussion the planning of the type of surgery or even in the decision of to preclude surgical treatment.

Sudden death in patients with Ebstein anomaly

Aims

Ventricular dysfunction or structural alteration of either ventricle is a well-established risk factor for sudden death (SD). Ebstein anomaly (EA) can present with both right and left heart abnormalities; however, predictors of SD have not been described. We therefore sought to characterize the incidence and risk factors of SD among a large cohort of patients with EA.

Methods and results

All EA patients who underwent evaluation at a high-volume institution over a 4-decade period were retrospectively reviewed. Clinical variables, cardiovascular surgical procedure(s), and cause of death were recorded. Sudden death incidence from birth and following tricuspid valve (TV) surgery were estimated using the Kaplan-Meier method. Cox regression analysis was used to identify clinical and surgical predictors of SD. The cohort comprised of 968 patients [mean age 25.3 years, 41.5% male; 79.8% severe EA, 18.6% accessory pathway, 0.74% implantable cardioverter-defibrillator (ICD) placement]. The 10-, 50-, and 70-year cumulative incidences of SD from birth were 0.8%, 8.3%, and 14.6%, respectively. Prior ventricular tachycardia [hazard ratio (HR) 6.37, P < 0.001)], heart failure (HR 5.64, P < 0.001), TV surgery (HR 5.94, P < 0.001), syncope (HR 2.03, P = 0.019), pulmonic stenosis (HR 3.42, P = 0.001), and haemoglobin > 15 g/dL (HR 2.05, P = 0.026) were multivariable predictors of SD. In a similar subgroup analysis of patients who underwent TV surgery, all of the above factors except syncope were significantly associated with post-operative SD on multivariable analysis.

Conclusion

Patients with EA are at significant risk for SD. Key clinical SD predictors identified can aid in risk stratification and potentially guide primary prevention ICD implantation.

Ebstein's Anomaly: "The One and a Half Ventricle Heart"

Objective

Ebstein's anomaly remains a relatively ignored disease. Lying in the 'No Man's land' between congenital and valve surgeons, it largely remains inadequately studied. We report our short-term results of treating it as a 'one and a half ventricle heart' and propose that the true tricuspid annulus (TTA) 'Z' score be used as an objective criterion for estimation of 'functional' right ventricle (RV).

Methods

22 consecutive patients undergoing surgery for Ebstein's anomaly were studied. Echocardiography was performed to assess the type and severity of the disease, tricuspid annular dimension and its 'Z' score. Patients were operated by a modification of the cone repair, with addition of annuloplasty, bidirectional cavopulmonary shunt (BCPS) and right reduction atrioplasty to provide a comprehensive repair. TTA 'Z' score was correlated later with postplication indexed residual RV volume.

Results

There was one (4.5%) early and no late postoperative death. There was a significant reduction in tricuspid regurgitation grading (3.40±0.65 to 1.22±0.42, P<0.001). Residual RV volume reduced to 71.96±3.8% of the expected volume and there was a significant negative correlation (rho −0.83) between TTA 'Z' score and indexed residual RV volume. During the follow-up of 20.54±7.62 months, the functional class improved from 2.59±0.7 to 1.34±0.52 (P<0.001).

Conclusion

In Ebstein's anomaly, a higher TTA 'Z' score correlates with a lower postplication indexed residual RV volume. Hence, a complete trileaflet repair with offloading of RV by BCPS (when the TTA 'Z' score is >2) is recommended. The short-term outcomes of our technique are promising.

Current Management of Ebstein's Anomaly in the Adult

OPINION STATEMENT

Ebstein's anomaly is a congenital malformation of the tricuspid valve and the right heart with a spectrum of clinical and morphologic presentations. Minor anomalies of the tricuspid valve may not be recognized until adulthood whereas major anomalies leading to heart failure and cyanosis require surgical intervention earlier in life. Echocardiography is the imaging modality of choice for both diagnosis and management of patients with Ebstein's anomaly. Surgical correction includes tricuspid valve repair or replacement and associated findings such as interatrial communications and arrhythmias should be addressed at the time of surgery. Pre-pregnancy evaluation should be considered in all Ebstein's anomaly patients and for those who are cyanotic, surgical correction must be considered due to the maternal and fetal ramifications of cyanosis in pregnancy. Most acyanotic Ebstein's anomaly patients are able to tolerate pregnancy with manageable or no complications. Those patients with mild anomalies and no right heart dilation can participate in sports whereas those with severe anomalies are discouraged from competitive sports. Physical activity as tolerated is important in all patients with adult congenital heart disease. Adult congenital heart specialists should evaluate patients prior to cardiac or noncardiac surgery. Longitudinal clinical follow-up in all Ebstein's anomaly patients (both repaired and unrepaired) is warranted to follow for signs and symptoms of heart failure, arrhythmias, cyanosis, and other associated findings. This should be ideally performed in collaboration with an adult congenital heart center of excellence.

Epicardial versus endocardial permanent pacing in adults with congenital heart disease

BACKGROUND

Permanent pacing (PM) in patients with congenital heart disease (CHD) presents unique challenges-with little known about the long-term outcomes.

METHODS

Pacemaker complications and reinterventions were reviewed over a 38-year period and were grouped by epicardial or endocardial approaches.

RESULTS

The average age at intervention was 37 ± 19 years for 106 patients and 259 PM procedures were performed (2.4 ± 2 per patient). From the first PM procedure, patients were followed for 11.6 ± 14 years. The most common indications for initial PM intervention were heart block (25%) and sinus node dysfunction (20%), yet reintervention was driven primarily by lead failure (49%). Endocardial systems were initially implanted in 73 patients (67%). Epicardial pacing was more common in patients with complex CHD (p = 0.006), cyanosis (p < 0.001), residual shunts (0.01), or Ebstein's anomaly (p = 0.01). Fifty-one devices (28%) developed lead or generator complications. Epicardial systems were most likely to develop lead failure (p < 0.0001), predominantly in the ventricular lead (p < 0.0001). Endocardial systems were found to be more durable than the epicardial systems (p = 0.023), and Ebstein's anomaly or an epicardial system was an independent predictor of lead failure.

CONCLUSIONS

Permanent pacing in CHD is associated with considerable morbidity and the need for repeat intervention, especially in those with Ebstein's anomaly. Epicardial pacing systems appear to have a higher incidence of lead failure and are significantly less durable in this group.

Successful Use of Transvenous Atrial and Bifocal Left Ventricular Pacing in Ebstein’s Anomaly After Tricuspid Prosthetic Valve Surgery

A 62-year-old woman with Ebstein's anomaly and a tricuspid valve prosthesis underwent placement of a permanent atrioventricular pacemaker to treat highly symptomatic sinus node dysfunction and atrioventricular block. Transvenous bipolar leads were placed in the anterior cardiac and lateral coronary veins and were set to optimal ventricular pacing parameters to preserve prosthetic valve function, back-up ventricular pacing, and maintain atrioventricular and interventricular synchrony. An atrial septal lead was placed to control atrial pacing. Interventricular and atrioventricular timing were optimized with the use of tissue Doppler imaging and the Doppler-derived stroke volume.

Ebstein Anomaly Associated With Unusual Conduction Delay and Sick Sinus Syndrome-A Case Report-

A 64-year-old man was admitted to our hospital because of palpitation, dyspnea on effort, and facial edema. The echocardiographic diagnosis was Ebstein anomaly. Although the 12-lead electrocardiogram showed an atrial rate of 150 beats/min and no typical flutter wave, the electrophysiological study showed counterclockwise rotation of excitation along the tricuspid annulus. Because of sinus arrest and syncope, a permanent pacemaker was implanted, but the right atrium was not captured by electrical stimulation at 5 V/0.4 ms, except for the orifice of coronary sinus, and the intracardiac P wave was only 0.2 mV or less. This is a rare case of Ebstein anomaly characterized by unusually prolonged conduction in the atrium, the basis of which was global myocardial damage, including the ventricles.

Electronic medical devices: a primer for pathologists

CONTEXT

Electronic medical devices (EMDs) with downloadable memories, such as implantable cardiac pacemakers, defibrillators, drug pumps, insulin pumps, and glucose monitors, are now an integral part of routine medical practice in the United States, and functional organ replacements, such as the artificial heart, pancreas, and retina, will most likely become commonplace in the near future. Often, EMDs end up in the hands of the pathologist as a surgical specimen or at autopsy. No established guidelines for systematic examination and reporting or comprehensive reviews of EMDs currently exist for the pathologist.

OBJECTIVE

To provide pathologists with a general overview of EMDs, including a brief history; epidemiology; essential technical aspects, indications, contraindications, and complications of selected devices; potential applications in pathology; relevant government regulations; and suggested examination and reporting guidelines.

DATA SOURCES

Articles indexed on PubMed of the National Library of Medicine, various medical and history of medicine textbooks, US Food and Drug Administration publications and product information, and specifications provided by device manufacturers.

STUDY SELECTION

Studies were selected on the basis of relevance to the study objectives.

DATA EXTRACTION

Descriptive data were selected by the author.

DATA SYNTHESIS

Suggested examination and reporting guidelines for EMDs received as surgical specimens and retrieved at autopsy.

CONCLUSIONS

Electronic medical devices received as surgical specimens and retrieved at autopsy are increasing in number and level of sophistication. They should be systematically examined and reported, should have electronic memories downloaded when indicated, will help pathologists answer more questions with greater certainty, and should become an integral part of the formal knowledge base, research focus, training, and practice of pathology.