Loss of Right Atrial Pacing Lead Capture Due to Myocardial Infarction Obscuring Diagnosis on Electrocardiogram.

Right coronary artery occlusion can lead to failure to capture from the right atrial pacing lead. In this case, acute infarction resulted in failure of the right atrial lead to capture and thus increased right ventricular pacing. The new ventricular pacing masked the diagnosis of acute myocardial infarction. (Level of Difficulty: Intermediate.).

Outcomes of Standard Permanent Active Fixation Leads for Temporary Pacing.

OBJECTIVES: This study investigated the performance of Temporary Pacing via an Externalized Active-Fixation (TPEAF) lead. BACKGROUND: The incidence of cardiac implantable electronic device infections is increasing, which necessitates the need for transvenous lead extraction (TLE). Pacemaker-dependent patients require temporary pacing during the guideline-recommended waiting period before reimplantation. Data regarding safety and efficacy of TPEAF leads are very limited. METHODS: We evaluated patients implanted with TPEAF leads post-TLE at our center between April 2004 and December 2017. RESULTS: TPEAF leads were placed in 158 patients. The mean age was 74 ± 11 years. The median duration of the temporary lead was 6 days (range 1 to 29). There were 4 procedural complications (2.5% incidence): 1 patient had cardiac arrest from hyperkalemia, 2 developed cardiac tamponade, and 1 had profuse bleeding from the entry point of the leads. There were 13 complications post-implantation (8.2% incidence): 8 lead dislodgments, 1 elevated pacing threshold, 2 vegetations on the temporary lead, 1 pneumothorax, and 1 loss of capture due to the generator "safety switch." All dislodgements occurred within 24 h, except 1 on day 3. Sixteen patients died during the hospital stay: 10 due to septic shock, 2 due to hyperkalemic cardiac arrest, 3 due to ventricular tachycardia, and 1 due to a massive cerebrovascular accident. CONCLUSIONS: The use of TPEAF leads is safe and efficacious in pacemaker-dependent patients post-TLE. Dislodgement can occur within the first 24 h. The presence of persistent fever and positive blood cultures should raise concern for vegetation on the temporary lead.

Outcomes of Acute Conduction Abnormalities Following Transcatheter Aortic Valve Implantation With a Balloon Expandable Valve and Predictors of Delayed Conduction System Abnormalities in Follow-up.

Transcatheter aortic valve implantation (TAVI) is an acceptable treatment for severe aortic stenosis in high or intermediate risk patients. Conduction abnormalities are a known complication of TAVI. Most abnormalities occur perioperatively but can develop later. The predictors of delayed conduction abnormalities are unknown. Patients who underwent TAVI at our institution were reviewed. Patients with a pre-existing pacemaker were excluded. Baseline, in-hospital, and 30-day follow-up ECGs were reviewed. Patient and procedural characteristics were analyzed to look for predictors of acute and delayed abnormalities. Ninety-eight patients were included. All valves implanted were balloon expandable, most commonly SAPIEN S3 (78%). Thirty-seven (37.7%) patients developed abnormalities before discharge. Of these patients, 20 (57.1%) had complete resolution at 30-day follow-up. No patients with new conduction abnormalities during hospitalization had additional abnormalities at 30-day follow-up. Five (5.1%) patients developed new conduction abnormalities following discharge. Overall, 22 (22.4%) patients had conduction abnormalities at 30-day follow-up which were not present at baseline. Predilatation (p = 0.003), higher ratios of balloon (p = 0.03) or valve (p = 0.05) size to left ventricular outflow tract, and previous myocardial infarction (p = 0.034) were predictive of acute conduction abnormalities. Baseline right bundle branch block (p = 0.002), longer baseline (p <0.001) and discharge (p = 0.004) QRS duration, moderate, or severe aortic insufficiency (p = 0.002) and atrial fibrillation (p = 0.031) were predictors of new conduction abnormalities after discharge. In conclusion, most new in-hospital conduction abnormalities resolve by 30-day follow-up. In-hospital conduction abnormalities are related to technical aspects of TAVI while delayed conduction abnormalities are related to baseline conduction system disease.