Ischemic QRS prolongation as a biomarker of myocardial injury in STEMI patients.

Background: Patients with acute coronary occlusion (ACO) may not only have ischemia-related ST-segment changes but also changes in the QRS complex. It has recently been shown in dogs that a greater ischemic QRS prolongation (IQP) during ACO is related to lower collateral flow. This suggests that greater IQP could indicate more severe ischemia and thereby more rapid infarct development.

Ischemic QRS prolongation as a predictor of ventricular fibrillation in a canine model.

Objectives: An acute coronary occlusion and its possible subsequent complications is one of the most common causes of death. One such complication is ventricular fibrillation (VF) due to myocardial ischemia. The severity of ischemia is related to the amount of coronary arterial collateral flow.

A 12-lead ECG-method for quantifying ischemia-induced QRS prolongation to estimate the severity of the acute myocardial event.

Introduction: Studies have shown terminal QRS distortion and resultant QRS prolongation during ischemia to be a sign of low cardiac protection and thus a faster rate of myocardial cell death. A recent study introduced a single lead method to quantify the severity of ischemia by estimating QRS prolongation. This paper introduces a 12-lead method that, in contrast to the previous method, does not require access to a prior ECG.

Ischemic QRS prolongation as a biomarker of severe myocardial ischemia.

Background: Previous studies have shown that QRS prolongation is a sign of depressed collateral flow and increased rate of myocardial cell death during coronary occlusion. The aims of this study were to evaluate ischemic QRS prolongation as a biomarker of severe ischemia by establishing the relationship between prolongation and collateral flow experimentally in a dog model, and test if the same pattern of ischemic QRS prolongation occurs in man.

Methods: Degree of ischemic QRS prolongation was measured using a novel method in dogs (n=23) and patients (n=52) during coronary occlusion for 5min.

Specificity for each of the 46 criteria of the Selvester QRS score for electrocardiographic myocardial scar sizing in left bundle branch block.

Background: The Selvester QRS score consists of a set of electrocardiographic criteria designed to identify, quantify and localize scar in the left ventricle using the morphology of the QRS complex. These criteria were updated in 2009 to expand their use to patients with underlying conduction abnormalities, but these versions have thus far only been validated in small and carefully selected populations.

Aim: To determine the specificity for each of the criteria of the left bundle branch block (LBBB) modified Selvester QRS Score (LB-SS) in a population with strict LBBB and no myocardial scar as verified by cardiovascular magnetic resonance imaging with late gadolinium enhancement (CMR-LGE).

Prevalence of manual Strauss LBBB criteria in patients diagnosed with the automated Glasgow LBBB criteria.

Introduction: About one-third of patients undergoing cardiac resynchronization therapy because of left bundle branch block (LBBB) and heart failure do not improve. Strauss et al. have developed strict criteria to more accurately define complete LBBB in this patient group.