Risk Of Pacemaker Implantation Research Articles

Pacemaker implantation after catheter ablation for atrial fibrillation.

Sinus node dysfunction requiring pacemaker implantation is commonly associated with atrial fibrillation (AF), but may not be clinically apparent until restoration of sinus rhythm with ablation or cardioversion. We sought to determine frequency, time course, and predictors for pacemaker implantation after catheter ablation, and to compare the overall rates to a matched cardioversion cohort. We conducted a retrospective analysis using a large US commercial insurance database and identified 12,158 AF patients who underwent catheter ablation between January 1, 2005 and December 31, 2012. Over an average of 2.4 years of follow-up, 5.6 % of the patients underwent pacemaker implantation. Using the Cox proportional hazards models, we found that risk of risks of pacemaker implantation was associated with older age (50-64 and ≥65 versus <50 years), female gender, higher CHADS2 score (≥2 and 1 versus 0), higher Charlson index (≥2 versus 0-1), certain baseline comorbidities (conduction disorder, coronary atherosclerosis, and congestive heart failure), and the year of ablation. There was no significant difference in the risk of pacemaker implantation between ablation patients and propensity score (PS)-matched cardioversion groups (3.5 versus. 4.1 % at 1 year and 8.8 versus 8.3 % at 5 years). Overall, pacemaker implantation occurs in about 1/28 patients within 1 year of catheter ablation. The overall implantation rate decreased between 2005 and 2012. Furthermore, the risk after ablation is similar to cardioversion, suggesting that patients require pacing due to a common underlying electrophysiologic substrate, rather than the ablation itself.

Is pre-TAVI EP study useful to predict risk of post-procedure pacemaker implantation?

Introduction: Recent studies have shown that Transcatheter Aortic Valve Implantation (TAVI) can induced severe conduction disorders. However, the usefulness and the time of electrophysiology (EP) study is still unclear. Methods: This single-center prospective study took place from December 2010 to Mai 2012 and included 81 patients. An ECG was realized before, immediately after and 24 hours after the procedure along with the registry of the electric modifications during the procedure. EP study was realized before and/or after TAVI. A follow up at one month with an ECG and clinical advents has been realized. Results: Out of the 81 patients, 74% were implanted with an Edwards valve and 26% with a Corevalve. The pacemaker implantation rate was respectively 16% and 35% (p=0.03). 30% of them underwent an EP study before and after TAVI. Risk factors correlated to a higher risk of permanent pacing are male gender (p=0.04), pre-existing right bundle branch block (p 200 ms (p=0.008), QRS width >120 ms (p=0.01), left axis deviation (p=0.003), larger valve diameter (26mm vs 24mm; p=0.04), prolonged HV interval (67.7 vs 57 ms; p=0.01), Corevalve (p=0.03), and renal insufficiency (p=0.04). The HV interval was significantly prolonged after TAVI (58.9 ms to 68.8ms, p=0.007). None of the patients with an initial HV interval below 60ms was implanted with a pacemaker. Furthermore, no patient with a pre-TAVI QRS width below 120 ms and a HV interval below 65 ms necessitated pacemaker implantation with a 100% positive predictive value. Conclusions: Some clinical and EP factors seem to be identified as risk factors for the implantation of a pacemaker post TAVI, such as male gender, a pre-TAVI wide QRS particularly RBBB, a prolonged PR interval, chronic renal failure, a larger valve diameter and the use of a Corevalve. QRS width combined to a pre-TAVI EP study appears to predict the risk of pacemaker implantation. However, these results need to be confirmed by larger studies.

EComment. Persistent annual risk for pacemaker implantation after aortic valve replacement

This interesting study by Baraki et al. addresses the long-term pacemaker dependency of patients who required a permanent pacemaker implantation after isolated aortic valve replacement [1]. After a mean follow-up time of 5.3 years, they found that the majority of their implanted patients remained pacemaker-dependent, whereas only 10% were no longer pacemaker-dependent. Therefore, they recommended early implantation of permanent pacemaker (PPM) in patient with high-grade atrioventricular blocks. We entirely agree with their opinion. However, the theoretical advantage of early PPM should be rigorously evaluated in larger clinical studies. Degenerative aortic stenosis is a disease affecting not only the aortic valve but also the surrounding tissue. Calcification can progress to engage the conduction system of the heart yielding electrical conduction abnormalities [2]. These degenerative changes at the level of the atrioventricular conduction system continue to progress even after aortic valve replacement especially in patient with previous conduction disturbances. Data on late PPM implantation rates after aortic valve replacement are scarce [3]. In a recently published retrospective study [2], Van Mieghem et al. found that patients with severe calcified aortic stenosis who underwent surgical aortic valve replacement have a persistent 1% annual risk for PPM implantation, and that patients with bundle branch block (BBB) at baseline or de novo had a higher PPM implantation incidence after aortic valve replacement than patients without BBB, both within 30 days after the operation and at the late follow-up. In considering the clinical implications of their findings, the authors suggest that patients with a BBB after aortic valve replacement should be monitored closely to detect severe conduction abnormalities. This is of utmost importance to determine subsequent treatment and to avoid syncope and sudden death [4]. Further randomized controlled studies with a larger sample size and a longer follow-up period will be mandatory before shortening the period of seven days of persistent atrioventricular block prior to PPM implantation advocated by the current European Society of Cardiology guidelines [5]. Conflict of interest: none declared.

Electrocardiographic and further predictors for permanent pacemaker requirement after transcatheter aortic valve implantation

The objective of this study was to identify electrocardiographic (ECG) and further predictors for atrioventricular (AV) block with a need for pacemaker (PM) implantation after transcatheter aortic valve implantation (TAVI). Pre- and post-procedural ECGs of patients with severe aortic stenosis and ongoing TAVI were investigated in a prospective study. From 50 consecutive patients enrolled in the study (mean age 80 +/- 6 years, 46% men), 17 (34%) experienced an AV block with subsequent requirement of a permanent PM [16 of 36 (44.4%) with CoreValve System and 1 of 14 (7.1%) with Edwards Sapiens System]. In patients with right bundle branch block (RBBB), PM implantation had to be performed more frequently [6 of 6 (100%) with CoreValve System and none with Edwards Sapiens System], P = 0.005. An AV block (Mobitz II second degree and third degree) occurred mostly within the first 24 h (range: Days 0-13) after the index procedure. No recovery of AV conduction with a change in PM indication occurred in a mean follow-up time of 13 +/- 6 days. Our data demonstrate that patients with pre-operative RBBB and those receiving CoreValve prosthesis are at a significantly higher risk for PM implantation after TAVI. Therefore, patients with the presence of RBBB before TAVI may be at lower risk for PM implantation using the Edwards Sapiens System.

Distrofia miotônica e cardiopatia: comportamento dos eventos arrítmicos e dos distúrbios da condução

To study the prevalence and natural evolution of arrhythmic events and conduction disturbances in myotonic dystrophy; to correlate the genetic defect with cardiovascular findings; to assess cardiac mortality, frequency, and predictive factors of sudden death; to correlate the severity of the neuromuscular and cardiac involvement; and to define the role of the electrophysiological study (EPS), in myotonic dystrophy. Periodic clinical assessment and the following tests were performed in 83 consecutive patients with a mean follow-up of 42+/-30.63 months: complementary examinations, genetic tests, electrocardiography, echocardiography, and Holter; electrophysiological study was performed in 59 cases. Atrial tachyarrhythmia was observed in 10 (12%) patients, NSVT in 14 (17%), first-degree AVB in 24 (29%), LBBB in 19 (23%), and RBBB in 13 (16%). Symptoms, an increase in the PR interval, QRS enlargement, LVEF < 60%, and age were predictive factors of death. Nine patients died (4 sudden deaths; 2 due to heart failure; 3 due to other causes). Electrophysiological study: H-V interval > 70 ms in 34% and > 100 ms in 11% (postprocainamide). The prevalence of arrhythmic events and conduction disturbances ranged from 50% to 80% after 6 years, and did not correlate with the genetic defect. Atrial flutter was the most common sustained arrhythmia. Cardiac involvement increased as the neuromuscular disease became aggravated, but progression of the cardiac involvement was more rapid than that of the neuromuscular disease. Overall mortality was low (11%) and sudden death occurred in half of the cases. The EPS identified a group at risk for pacemaker implantation.