Ventricular arrhythmia burst is an independent indicator of larger infarct size even in optimal reperfusion in STEMI.

Objective: We hypothesized that ventricular arrhythmia (VA) bursts during reperfusion phase are a marker of larger infarct size despite optimal epicardial and microvascular perfusion.

Methods: 126 STEMI patients were studied with 24h continuous, 12-lead Holter monitoring. Myocardial blush grade (MBG) was determined and VA bursts were identified against subject-specific background VA rates in core laboratories.

Implications of ventricular arrhythmia "bursts" with normal epicardial flow, myocardial blush, and ST-segment recovery in anterior ST-elevation myocardial infarction reperfusion: a biosignature of direct myocellular injury "downstream of downstream".

Aims: Establishing epicardial flow with percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) is necessary but not sufficient to ensure nutritive myocardial reperfusion. We evaluated whether adding myocardial blush grade (MBG) and quantitative reperfusion ventricular arrhythmia "bursts" (VABs) surrogates provide a more informative biosignature of optimal reperfusion in patients with Thrombolysis in Myocardial Infarction (TIMI) 3 flow and ST-segment recovery (STR).

Methods And Results: Anterior STEMI patients with final TIMI 3 flow had protocol-blinded analyses of simultaneous MBG, continuous 12-lead electrocardiogram (ECG) STR, Holter VABs, and day 5-14 SPECT imaging infarct size (IS) assessments.

Impact of early, late, and no ST-segment resolution measured by continuous ST Holter monitoring on left ventricular ejection fraction and infarct size as determined by cardiovascular magnetic resonance imaging.

Background: The goal of this study is to determine the predictive value of ST-segment resolution (STR) early after percutaneous coronary intervention (PCI), late STR, and no STR for left ventricular ejection fraction (LVEF) and infarct size (IS) by cardiovascular magnetic resonance (CMR) at follow-up in patients with ST-segment elevation myocardial infarction.

Methods: The analysis included 199 patients who were enrolled in the PRoximal Embolic Protection in Acute myocardial infarction and Resolution of ST-Elevation trial and in whom both continuous ST Holter and CMR at follow-up were available. Patients were stratified into 3 groups: (1) early complete (≥70%) STR measured immediately after last contrast injection (n = 113); (2) late complete STR (n = 52), defined as complete STR from 30 to 240 minutes after PCI; and (3) no complete STR after 240 minutes (n = 34).

RR-interval irregularity precedes ventricular fibrillation in ST elevation acute myocardial infarction.

Background: Sudden cardiac arrest is a leading cause of death in industrialized countries, and ischemic ventricular fibrillation (VF) is a frequent cause.

Objective: The purpose of this study was to determine whether patients with ST elevation myocardial infarction (STEMI) who develop ischemic VF show more overall RR-interval irregularity (RRI) than do STEMI patients without ischemic VF.

Methods: Ischemic VF was identified in 41 patients from 1,473 digital 12-lead Holter recordings from three separate STEMI studies.

Reperfusion ventricular arrhythmia 'bursts' predict larger infarct size despite TIMI 3 flow restoration with primary angioplasty for anterior ST-elevation myocardial infarction.

Aims Successful epicardial reperfusion with primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) can paradoxically evoke myocardial reperfusion injury, which may be signalled by temporally associated ventricular arrhythmias (VAs). We correlated reperfusion VA 'bursts' with final infarct size (IS) in patients with restored TIMI 3 flow following PCI for anterior STEMI. Methods and results All 128 anterior STEMI patients with final TIMI 3 flow had continuous 24 h digital 12-lead ECG with simultaneous Holter recording initiated prior to PCI, and Day 7/discharge SPECT imaging IS assessment.

Preexcitation and myocardial infarction: conditions with confusing electrocardiographic manifestations.

The electrocardiogram allows easy recognition of myocardial infarction and preexcitation syndromes but may cause confusion when both conditions are present simultaneously. Two cases where myocardial infarction is masked and/or mimicked by a preexcitation syndrome are presented.

Reperfusion ventricular arrhythmia 'bursts' in TIMI 3 flow restoration with primary angioplasty for anterior ST-elevation myocardial infarction: a more precise definition of reperfusion arrhythmias.

Aims: We sought to define reperfusion-induced ventricular arrhythmias (VAs) more precisely through simultaneous angiography, continuous ST-segment recovery, and beat-to-beat Holter analyses in subjects with anterior ST-elevation myocardial infarction (STEMI) undergoing primary angioplasty [percutaneous coronary intervention (PCI)].

Methods And Results: All 157 subjects with final TIMI 3 flow had continuous 12-lead electrocardiography with simultaneous Holter recording initiated prior to PCI for continuous ST-segment recovery and quantitative VA analyses. Ventricular arrhythmia bursts were detected against subject-specific background VA rates using a statistical outlier method.

Effects of acute atrial dilation on heterogeneity in conduction in the isolated rabbit heart.

Introduction: Atrial dilation plays an important role in the development and persistence of atrial fibrillation (AF). The mechanisms by which atrial dilation increases the vulnerability to AF are not fully understood.

Methods And Results: In 11 isolated rabbit hearts, the right atrium was acutely dilated by increasing the intra-atrial pressure from 2 to 9 and 14 cm H2O.