The Right Ventricle in Congenital Heart Disease

Comparative effects of surgical and percutaneous repair on P-wave and atrioventricular conduction in patients with atrial septal defect--ostium secundum type

Both surgical and percutaneous closures of atrial septal defects have been successful in reversal of atrial dilatation. We compared the effects of surgical and percutaneous transvenous device closure of atrial septal defect on post-operative changes of P-wave duration, PR segment, and PR interval. Electrocardiographic data were prospectively collected from 30 patients following either surgical (n equal to 16) or percutaneous (n equal to 16) repair of atrial septal defects between 2004 and 2010. A cardiologist blinded to the closure technique performed the electrocardiographic analyses. P-wave duration (98.5 plus or minus 15.4 to 86.4 plus or minus 13.2 milliseconds, p-value less than 0.05) and PR interval (162.9 plus or minus 18.5 to 140.6 plus or minus 15.2 milliseconds, p-value less than 0.05) were reduced after percutaneous transvenous device closure. P-wave duration (104.5 plus or minus 24.7 versus 83.2 plus or minus 13.3 milliseconds, p-value less than 0.05) and PR interval (173.2 plus or minus 38.7 versus 144.3 plus or minus 32.0 milliseconds, p-value less than 0.05) were also reduced after surgical closure. PR segment in the percutaneous group was significantly reduced (63.4 plus or minus 14.5 to 52.1 plus or minus 10.8 milliseconds, p-value less than 0.05), but not in the surgical group (68.6 plus or minus 18.7 versus 61.1 plus or minus 24.7 milliseconds). However, the difference in PR segment changes between the two groups was not significant (-11.3 plus or minus 15.0 versus -7.6 plus or minus 20.5 milliseconds, p-value equal to 0.18). Our analysis demonstrates that the changes between the two groups were not different and that both closure techniques reduce P-wave duration, PR segment, and PR interval within 6 months.

Evaluation of right ventricular function in early period following transcatheter closure of atrial septal defect

AIMS

There is limited data on alterations in novel right ventricular (RV) function indices like tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular systolic velocity (TASV) after transcatheter atrial septal defect (ASD) closure. We aimed to evaluate RV function by echocardiography (ECG) with these novel indices in early period in patients with secundum-type ASD that was closed percutaneously.

METHODS

Patients were enrolled to study if they had secundum-type ASD that was suitable for percutaneous closure. Patient population consisted of 4 men and 16 women. Echocardiography was performed before and 1 month after closure.

RESULTS

Mean age was 37 ± 16. Mean diameter of ASD and total atrial septum length measured by ECG were 19 ± 6 mm and 49 ± 7 mm, respectively. Mean diameter of defect in transesophageal echocardiography was 20 ± 6 mm. Stretched mean diameter in catheterization was 23 ± 6 mm. One month after closure, there were statistically significant decreases in RV end-diastolic diameters (43.3 ± 10.7 mm vs. 34.9 ± 5.5 mm; P < 0.001), RV/left ventricular (LV) end-diastolic diameter ratio (1.1 ± 0.3 vs. 0.87 ± 0.1; P < 0.001), TASV (16.9 ± 3.2 cm/sec vs. 14.3 ± 3.3 cm/sec; P < 0.05), early diastolic tricuspid annular velocity (15.3 ± 3.1 cm/sec vs. 13.4 ± 2.4 cm/sec P <0.05), late diastolic tricuspid annular velocity (16.2 ± 5.4 cm/sec vs. 14.3 ± 6.3 cm/sec; P < 0.05), and TAPSE (29.9 ± 6.2 mm vs. 22.4 ± 7.4 mm; P < 0.001). LV end-diastolic diameter (38.0 ± 6.9 mm and 40.0 ± 4.5 P < 0.05) was increased, whereas there was no change in LV ejection fraction.

CONCLUSION

Closure of ASD by using Amplatzer devices led to decrease in right heart chamber size, tissue Doppler-derived tricuspid annular velocities and TAPSE in early period.

Results of the U.S. Multicenter Pivotal Study of the HELEX Septal Occluder for Percutaneous Closure of Secundum Atrial Septal Defects

OBJECTIVES

This study sought to compare the safety and efficacy of the HELEX septal occluder (HSO) with surgical repair of atrial septal defect (ASD).

BACKGROUND

The HSO is a low-profile, double-disk occluder device for percutaneous closure of secundum ASD.

METHODS

Patients were enrolled (HSO arm prospectively, surgery arm prospectively/retrospectively) from 14 U.S. sites and followed up for 12 months postprocedure. Investigator-reported outcomes were evaluated, including closure success (no or clinically insignificant residual shunt) and the incidence of adverse events. The first 3 HSO patients at each site were considered training cases and were excluded from analysis.

RESULTS

Between March 2001 and April 2003, 119 nontraining cases received an HSO and 128 had surgical repair. The groups were similar with statistical but clinically unimportant differences in median age, weight, and preprocedural echocardiographic defect size. Anesthesia time and hospital stay were significantly shorter in the HSO group. Closure success, defined as complete closure or a clinically insignificant residual shunt, was similar in both groups. Major and minor adverse events rates were not statistically different. The most common major adverse events for the HSO group was device embolization requiring catheter retreival (1.7%), and in the surgery group was postpericardiotomy syndrome (6.3%), including one death because of tamponade. The primary end point, clinical success, a composite of closure success and no major adverse events at 12 months, satisfied the noninferiority hypothesis comparing device closure with surgery.

CONCLUSIONS

Closure of ASD with the HELEX septal occluder is safe and effective when compared with surgical repair, with reduced anesthesia time and hospital stay. (U.S. Multicenter Pivotal Study of the HELEX Septal Occluder for Percutaneous Closure of Secundum Atrial Septal Defects; this study was approved by the Food and Drug Administration before the National Institutes of Health website was active, so there is not a URL or registration number.).

Cardiac resynchronization therapy in congenital heart disease

While cardiac resynchronization therapy (CRT) is of proven benefit in selected patients with severe ischemic or dilated cardiomyopathy, refractory symptoms, and conduction delay, extrapolation to congenital heart disease is not straightforward. This rapidly expanding patient population commonly suffers from heart failure, particularly in the presence of a single or systemic right ventricle. Surgical repair may also contribute to ventricular asynchrony. In this systematic review, the current state of knowledge regarding CRT in congenital heart disease is presented. Issues specific to congenital heart disease including right bundle branch block, right (pulmonary) ventricular dysfunction, systemic right ventricular dysfunction, and single ventricle dysfunction are explored. Evidence-based CRT applications for each of these particular conditions are reviewed. Initial experience with CRT in the acute postoperative setting and longer-term, including our own, is elaborated. Unlike standard indications based on multiple randomized clinical trials, supporting evidence for CRT in congenital heart disease is limited to case reports, case series, and small experimental crossover studies in the acute postoperative setting. The heterogeneous patient population, technical limitations from patient size, vascular access issues, and unique forms of ventricular asynchrony further obscure the selection of potential beneficiaries. Despite these limitations, experience thus far has been favorable. Quality of current data precludes definitive evidence-based recommendations, but optimistic initial results suggest that research endeavors in this field should be pursued. Multicenter prospective collaborative efforts are to be encouraged.

Pregnancy Outcomes in Women With Congenital Heart Disease

Background— Pregnant women with congenital heart disease are at increased risk for cardiac and neonatal complications, yet risk factors for adverse outcomes are not fully defined.

Methods and Results— Between January 1998 and September 2004, 90 pregnancies at age 27.7±6.1 years were followed in 53 women with congenital heart disease. Spontaneous abortions occurred in 11 pregnancies at 10.8±3.7 weeks, and 7 underwent elective pregnancy termination. There were no maternal deaths. Primary maternal cardiac events complicated 19.4% of ongoing pregnancies, with pulmonary edema in 16.7% and sustained arrhythmias in 2.8%. Univariate risk factors included prior history of heart failure (odds ratio [OR], 15.5), NYHA functional class ≥2 (OR, 5.4), and decreased subpulmonary ventricular ejection fraction (OR, 7.7). Independent predictors were decreased subpulmonary ventricular ejection fraction and/or severe pulmonary regurgitation (OR, 9.0) and smoking history (OR, 27.2). Adverse neonatal outcomes occurred in 27.8% of ongoing pregnancies and included preterm delivery (20.8%), small for gestational age (8.3%), respiratory distress syndrome (8.3%), intraventricular hemorrhage (1.4%), intrauterine fetal demise (2.8%), and neonatal death (1.4%). A subaortic ventricular outflow tract gradient >30 mm Hg independently predicted an adverse neonatal outcome (OR, 7.5). Cardiac risk assessment was improved by including decreased subpulmonary ventricular systolic function and/or severe pulmonary regurgitation (OR, 10.3) in a previously proposed risk index developed in pregnant women with acquired and congenital heart disease.

Conclusions— Maternal cardiac and neonatal complication rates are considerable in pregnant women with congenital heart disease. Patients with impaired subpulmonary ventricular systolic function and/or severe pulmonary regurgitation are at increased risk for adverse cardiac outcomes.

Outcomes and alternative techniques for device closure of the large secundum atrial septal defect

Outcomes of device closure of large and small secundum atrial septal defects (ASDs) as related to rim anatomy with the Amplatzer atrial septal occluder were compared. Rim adequacy (> or = 5mm) of the anterior, inferior, posterior, and superior rims was determined using transesophageal echocardiography. Balloon-stretched defect size defined patients into two groups: group 1, < or = 25 mm (n = 138); group 2, > 25 mm (n = 34). Rim deficiency (n = 62) was more frequent in group 2 compared to group 1 (50% vs. 33%; P = 0.07), especially inferior rim deficiency (35% vs. 2%; P = 0.005). Device deployment was successful in group 1 and group 2 (100% vs. 91%; P = 0.007). Unsuccessful deployment was associated with an ASD of > 25 mm (P = 0.007) and inferior rim deficiency (P = 0.001). At first follow-up (54 +/- 16 days), right ventricular systolic pressure had improved in both groups (P < 0.001). Closure of a large ASD associated with a lack of support in the inferior rim may warrant alternative strategies to position the device successfully.

Right ventricular form and function after percutaneous atrial septal defect device closure

OBJECTIVES

We sought to assess the right heart's response to percutaneous device closure of moderate sized atrial septal defects (ASDs) in adults over a one-year follow-up period.

BACKGROUND

Percutaneous ASD device closure is a safe and effective means of reducing or eliminating interatrial shunting. The response of the adult's right heart to device closure is incompletely understood.

METHODS

Forty consecutive patients had 40 device implantations (32 with the CardioSeal implant and 8 with the Amplatzer device). The patients were assessed with echocardiography, chest radiography and electrocardiography before the procedure and at 1, 6 and 12 months.

RESULTS

The mean ASD size was 13+/-4 mm, and the device size ranged from 33 to 40 mm for CardioSeal and 12 to 36 mm for Amplatzer. At one month, heart size (49% vs. 46%), four-chamber right ventricular (RV) size (45 vs. 41 mm), paradoxical septal motion (60% vs. 5%), QRS duration (125 vs. 119 ms), PR interval (181 vs. 155 ms) and echocardiographically determined pulmonary artery systolic pressure decreased significantly and was maintained at 12-month follow-up. At six months, right atrial length decreased from 50 to 47 mm. At one year, 29% of patients had persistent RV enlargement.

CONCLUSIONS

Right heart morphology undergoes rapid improvement within one month of defect closure, with associated mechanoelectrical benefit. A small number of patients had persistent RV enlargement or pulmonary hypertension, or both, at one year. Our data support the application of transcatheter methods in achieving excellent hemodynamic and anatomic outcomes.

Right ventricular injury in young swine: effects of catecholamines on right ventricular function and pulmonary vascular mechanics

Acute right ventricular (RV) injury is commonly encountered in infants and children after cardiac surgery. Empiric medical therapy for these patients results from a paucity of data on which to base medical management and the absence of animal models that allow rigorous laboratory testing. Specifically, exogenous catecholamines have unclear effects on the injured right ventricle and pulmonary vasculature in the young. Ten anesthetized piglets (9-12 kg) were instrumented with epicardial transducers, micromanometers, and a pulmonary artery flow probe. RV injury was induced with a cryoablation probe. Dopamine at 10 microg/kg/min, dobutamine at 10 microg/kg/min, and epinephrine (EP) at 0.1 microg/kg/min were infused in a random order. RV contractility was evaluated using preload recruitable stroke work. Diastolic function was described by the end-diastolic pressure-volume relation, peak negative derivative of the pressure waveform, and peak filling rate. In addition to routine hemodynamic measurements, Fourier transformation of the pressure and flow waveforms allowed calculation of input resistance, characteristic impedance, RV total hydraulic power, and transpulmonary vascular efficiency. Cryoablation led to a stable reproducible injury, decreased preload recruitable stroke work, and impaired diastolic function as measured by all three indices. Infusion of each catecholamine improved preload recruitable stroke work and peak negative derivative of the pressure waveform. Dobutamine and EP both decreased indices of pulmonary vascular impedance, whereas EP was the only inotrope that significantly improved transpulmonary vascular efficiency. Although all three inotropes improved systolic and diastolic RV function, only EP decreased input resistance, decreased pulmonary vascular resistance, and increased transpulmonary vascular efficiency.