Effect of dual-chamber pacemaker implantation on aortic dilatation in patients with congenital heart block

Impact of aortic root size on left ventricular afterload and stroke volume

PURPOSE

The left ventricle (LV) ejects blood into the proximal aorta. Age and hypertension are associated with stiffening and dilation of the aortic root, typically viewed as indicative of adverse remodeling. Based on analytical considerations, we hypothesized that a larger aortic root should be associated with lower global afterload (effective arterial elastance, EA) and larger stroke volume (SV). Moreover, as antihypertensive drugs differ in their effect on central blood pressure, we examined the role of antihypertensive drugs for the relation between aortic root size and afterload.

METHODS

We studied a large group of patients (n = 1250; 61 ± 12 years; 78 % males; 64 % hypertensives) from a single-center registry with known or suspected coronary artery disease. Aortic root size was measured by echocardiography as the diameter of the tubular portion of the ascending aorta. LV outflow tract Doppler was used to record SV.

RESULTS

In the population as a whole, after adjusting for key covariates in separate regression models, aortic root size was an independent determinant of both SV and EA. This association was found to be heterogeneous and stronger in patients taking a calcium channel blocker (CCB; 10.6 % of entire population; aortic root size accounted for 8 % of the explained variance of EA).

CONCLUSION

Larger aortic root size is an independent determinant of EA and SV. This association was heterogeneous and stronger in patients on CCB therapy.

Aortic dilatation in patients with Turner's syndrome without structural cardiac anomaly

INTRODUCTION

Dilatation of the ascending aorta is described in Turner's syndrome with variable prevalence (6.8-32%). Reported series typically include patients with associated cardiac anomalies.

OBJECTIVE

To characterise the prevalence, age of onset, and the progress of dilatation of the ascending aorta in Turner's syndrome patients free of structural cardiac anomalies. Potential risk factors such as karyotype and growth hormone therapy were analysed for correlation with aortic dilatation.

METHODS

We carried out a retrospective study with data collected from medical records and echocardiography studies. Patients with Tuner's syndrome followed-up between 1992 and 2010 with at least two echocardiography studies were eligible. Patients with previous cardiac surgery or under anti-hypertensive medication were excluded. Ascending aorta diameter measurements were adjusted for body surface area, and dilatation was defined as Z-score>2.

RESULTS

The study population consisted of 44 patients, aged 11.9±7.4 years at the first echocardiogram and 17.9±7.3 years at the last follow-up, with a follow-up duration of 6.0±3.7 years. A total of 13 (29.5%) patients exhibited aortic dilatation during follow-up, suggesting an actuarial estimate of the freedom from aortic dilatation dropping from 86 to 70% and then to 37% at 10, 20, and 30 years of age, respectively. There was no statistically significant impact of karyotype or growth hormone therapy on aortic Z-score progression.

CONCLUSION

The prevalence of dilatation of the ascending aorta in Turner's syndrome patients free of structural aortic anomalies is comparable with published data with associated lesions. Growth hormone therapy and karyotype had no significant impact; however, longitudinal follow-up is warranted.

Congenital heart block related to maternal autoantibodies: descriptive analysis of a series of 18 cases from a single center

The objective of this study was to describe the clinical and immunological characteristics of maternal autoimmune-mediated fetal congenital heart block (CHB) in a cohort of pregnant women from an autoimmune disease pregnancy clinic. This is a retrospective observational study of all women presenting with CHB in our autoimmune disease pregnancy clinic from January 1997 to December 2014. In addition, perinatal outcome is also described. Fourteen patients accounting for 18 fetuses with CHB were identified. The median age was 32.5 years (range, 22-40). Seven (50 %) patients had Sjögren's syndrome, and the remaining seven were asymptomatic carriers of autoantibodies. All patients had anti-Ro/SSA antibodies, and 11/13 (85 %) had anti-La/SSB antibodies. The median gestational age at the time of CHB was 22 weeks (range 18-28). Complete third degree CHB was detected in 12 (67 %). Seven cases of CHB were treated with dexamethasone, two with ritodrine, and one with the association of dexamethasone, ritodrine, and terbutaline. In 9 (50 %) cases that presented with, or developed, very poor prognosis factors, such as a ventricular rate below 50-55 bpm and/or the presence of fetal hydrops, parents opted for the termination of pregnancy, after dedicated counseling. Finally, there were nine newborns (seven males [78 %]) with median age at delivery of 37 weeks (range, 32-39). A definitive epicardial pacemaker was placed in six newborns, four of them within 2 weeks of life. CHB is a severe complication related to maternal anti-Ro/SSA and anti-La/SSB antibodies. Our results confirm previous data showing that therapy is ineffective, and most of the surviving patients will require neonatal pacemaker.