Lenz, Charles J.

AbstractIntroductionCardiac pacing from the right ventricular apex is associated with detrimental long‐term effects and nonapical pacing locations may be associated with improved outcomes. There is little data regarding complications with nonapical lead positions. The aim of this study was to assess long‐term outcomes and lead‐related complications associated with differing ventricular lead tip position.Methods and resultsAll adult patients who underwent dual‐chamber pacemaker implantation from 2004 to 2014 were included if they had postprocedure chest radiographs amenable to lead position determination. Long‐term outcomes and lead‐related complication rates were recorded. These were compared at 5 years between: (1) apical and septal leads, (2) apical and nonseptal nonapical (NSNA), and (3) apical and septal with >40% ventricular pacing. We retrospectively evaluated 3,450 patients, which included 238 with a septal position and 733 with NSNA lead positions. Septal lead position was associated with a lower mortality compared to apical leads (24% vs. 31%, P = 0.02). In patients with greater than 40% pacing, septal leads were associated with significantly higher rates of incident atrial fibrillation compared to apical leads (49% vs. 34%, P = 0.04). NSNA positions were associated with a significantly higher rate of lead dislodgement (4% vs. 2%, P = 0.005) and need for revision (8% vs. 5%, P = 0.005).ConclusionsSeptal pacemaker lead position is associated with a lower mortality compared to apically placed leads, but a higher incidence of atrial fibrillation with higher percentage ventricular pacing. NSNA lead locations are associated with more complications and should be avoided.

PurposeInfarct mass as assessed by myocardial‐delayed enhancement imaging on cardiac magnetic resonance (CMR) and myocardial blood flow as assessed by real time myocardial perfusion echocardiography (RT‐MPE) have been shown to predict adverse events following ST elevation myocardial infarction (STEMI). There has been no published comparison of quantitative assessment using these modalities as predictors of clinical outcomes to date. We compared RT‐MPE with CMR for prediction of cardiac events in reperfused STEMI patients.Materials and MethodsConsecutive STEMI patients with early reperfusion were studied. RT‐MPE and CMR were performed. Perfusion score indices (PSIRT‐MPE and PSICMR) were calculated [sum of segmental perfusion scores/number of segments]. CMR infarct mass (g) and RT‐MPE myocardial blood flow (MBF dB/s) were quantified. Patients were followed for cardiac events (death, nonfatal MI, revascularization, angina, and heart failure).ResultsAll 27 patients (age 62±14; follow‐up 3.5±2.6 years) had thrombolysis in myocardial infarction (TIMI) grade 3 flow of infarct vessel. Cardiac events occurred in 17 (63%). Cardiac event patients had higher PSIRT‐MPE, PSICMR, infarct mass, and lower MBF. PSIRT‐MPE cutoff of 0.3 had an AUC of 0.856 (82% sensitivity, 70% specificity), while a PSICMR cutoff of 0.2 had an AUC of 0.765 (76% sensitivity, 60% specificity). Infarct mass and MBF were independent predictors of cardiac events after adjusting for risk factors (hazard ratios: 20.9 [95% CI 1.8–256] P=.02 and 8.1 [95% CI 1.5–78] P=.01, respectively).ConclusionsQuantitative RT‐MPE performed comparably to CMR for prediction of MACE in STEMI patients supporting a prognostic role for this noninvasive, bedside imaging method.