Rates of permanent pacemaker implantation for complete heart block complicating pregnancy: a nationwide analysis of 20,451,108 pregnant patients in the USA

Introduction Complete heart block (CHB), also known as third-degree heart block, occurs when there is complete dissociation of the atria and ventricles. CHB during pregnancy is extremely rare and one possible mechanism may be related to the stretching of the atria during pregnancy causing conduction defects Purpose There is limited data on the rates of CHB and pacemaker (PPM) use in pregnant patients, with only a few case reports published. In this study we sought to define the rates of permanent pacemaker implantation for CHB complicating pregnancy. Methods The Nationwide Inpatient Sample was queried from 2010 to 2014 using the International Classification of Diseases, 9th revision diagnosis codes for pregnancy and CHB and procedure codes for PPM in any procedure field for patients 18 years or older. Results From 2010 to 2014, we identified 20,451,108 pregnancies in patients above the age of 18 years. The overall rates of CHB were 643 (0.0031%). The sample consisted of 643 patients (Mage= 29.28±6.42 years) with CHB, the majority of whom were Caucasians 328 (51%). Average length of stay (LOS) (M ± SD) was 4.94±7.859 and total hospitalization charges were 51,715.04±112,345.98 ($). Moreover, the occurrence of other conditions which could lead to the development of CHB was: sarcoidosis 0 (0%), systemic lupus erythematosus 5 (0.8%), prior myocardial infarction 25 (3.8%), Lyme disease 0 (0%). Among patients with CHB, PPM implantation was done in 60 (9.3%), and TVP were 5 (0.8%). The overall composite mortality rates were 21 (3.2%). On comparing the non-PPM group to the PPM group, rates of in-hospital mortality were 3.6% vs 0%; p=0.059, LOS were 4.49±5.01 vs 12.50±15.35; p<0.001, complications such as congestive heart failure 0% vs 8.4%; p<0.001, cardiogenic shock 1% vs 8.4%; p<0.001, respiratory failure needing mechanical ventilation 1.7% vs 0; p<0.04, sudden cardiac death 3.4% vs 0; p<0.05. Conclusions The overall rates of CHB were 3.1 in 100,000 pregnancies. There were no reported in-hospital deaths among pregnant patients with CHB who received PPM and TVP. Relatively lower rates of PPM implantation in these patients might indicate that CHB during pregnancy is less severe and patients may have a stable narrow complex junctional escape rhythm. PPM implantation is recommended for those who are symptomatic or have a slow wide QRS complex rhythm indicating a block below the bundle of His.With this study we attempt to better define the occurrence of CHB during pregnancy, which could lead to better understanding and management of this condition. Funding Acknowledgement Type of funding source: None