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. Over 20 million cardiac cycles from >4500 h of continuous ECG monitoring in subjects with STR were obtained. IS and clinical outcomes were examined in patients stratified by MBG and VABs. VABs occurred in 51% (79/154) of subjects. Microcirculation (MBG 2/3) was restored in 75% (115/154) of subjects, of whom 53% (61/115) had VABs. No VABs were observed in subjects without microvascular flow (MBG of 0). Of 115 patients with TIMI 3 flow, STR, and MBG 2/3, those with VABs had significantly larger IS (median: 23.0% vs 6.0%, p=0.001). Multivariable analysis identified reperfusion VABs as a factor significantly associated with larger IS (p=0.015). CONCLUSIONS: Despite restoration of normal epicardial flow, open microcirculation, and STR, concomitant VABs are associated with larger myocardial IS, possibly reflecting myocellular injury in reperfusion settings. Combining angiographic and ECG parameters of epicardial, microvascular, and cellular response to STEMI intervention provides a more predictive "biosignature" of optimal reperfusion than do single surrogate markers.

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. Angiography, SPECT imaging, continuous ST recovery, and quantitative rhythm analyses were performed. Reperfusion VA bursts were defined against patient-specific background VA rates and timed as concomitant with or following first angiographic TIMI 3 flow restoration associated with > or =50% stable ST recovery; they were then correlated with IS and global left ventricular ejection fraction (LVEF) at Day 7/discharge. Bursts occurred in 81/128 (63%) patients and were significantly correlated with larger IS and worse LVEF (median: 21.0 vs. 10.0%, P < 0.001; 35.5 vs. 46.5%, P < 0.001, respectively). In multivariable analyses that adjusted for known predictors of IS, the association of bursts with larger IS remained significant; similar results were seen for worse LVEF. Conclusion Reperfusion VA bursts predict larger IS despite TIMI 3 flow restoration with > or =50% stable ST recovery following PCI for anterior STEMI. Well-characterized reperfusion VAs may provide a novel biomarker of reperfusion injury.

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. For temporal correlations, timing and quality of reperfusion were defined as first angiographic TIMI 3 flow with >or=50% stable ST-segment recovery. Almost all subjects had VAs [156/157 (99%)], whereas VA bursts during or subsequent to reperfusion occurred in 97/157 (62%). The majority of VA bursts (72%) arose within 20 min of reperfusion (95% CI: 26.7, 72), with onset at a median of 4 min post-reperfusion (IQR: 0-43) Bursts comprised a median of 1290 ventricular premature complexes (VPCs) (IQR: 415-4632) and persisted for a median of 105 min (IQR: 35-250). Most background VAs occurred as single VPCs; bursts typically comprised runs of three or more VPCs. Subjects with bursts had higher absolute peak ST segments and more frequent worsening of ST elevation immediately after reperfusion. CONCLUSION: Ventricular arrhythmia bursts temporally associated with TIMI 3 flow restoration and stable ST-segment recovery (reperfusion VA bursts) can be precisely defined in subjects with anterior STEMI and may constitute a unique electric biosignal of myocellular response to reperfusion.