Evaluation of depolarization changes during acute myocardial ischemia by analysis of QRS slopes.

OBJECTIVE This study evaluates depolarization changes in acute myocardial ischemia by analysis of QRS slopes. METHODS In 38 patients undergoing elective percutaneous coronary intervention, changes in upward slope between Q and R waves and downward slope between R and S waves (DS) were analyzed. In leads V1 to V3, upward slope of the S wave was additionally analyzed. Ischemia was quantified by myocardial scintigraphy. Also, conventional QRS and ST measures were determined. RESULTS QRS slope changes correlated significantly with ischemia (for DS: r = 0.71, P < .0001 for extent, and r = 0.73, P < .0001 for severity). Best corresponding correlation for conventional electrocardiogram parameters was the sum of R-wave amplitude change (r = 0.63, P < .0001; r = 0.60, P < .0001) and the sum of ST-segment elevation (r = 0.67, P < .0001; r = 0.73, P < .0001). Prediction of extent and severity of ischemia increased by 12.2% and 7.1% by adding DS to ST. CONCLUSIONS The downward slope between R and S waves correlates with ischemia and could have potential value in risk stratification in acute ischemia in addition to ST-T analysis.

[1]  B. Surawicz,et al.  QRS changes during percutaneous transluminal coronary angioplasty and their possible mechanisms. , 1997, Journal of the American College of Cardiology.

[2]  R. E. Mason,et al.  A new system of multiple-lead exercise electrocardiography. , 1966, American heart journal.

[3]  Pablo Laguna,et al.  Depolarization Changes During Acute Myocardial Ischemia by Evaluation of QRS Slopes: Standard Lead and Vectorial Approach , 2011, IEEE Transactions on Biomedical Engineering.

[4]  B. Surawicz,et al.  Reversible QRS changes during acute myocardial ischemia. , 1998, Journal of electrocardiology.

[5]  O Pahlm,et al.  Changes in high-frequency QRS components are more sensitive than ST-segment deviation for detecting acute coronary artery occlusion. , 2000, Journal of the American College of Cardiology.

[6]  G. Wagner,et al.  Grade 3 ischemia on the admission electrocardiogram predicts rapid progression of necrosis over time and less myocardial salvage by primary angioplasty. , 2005, Journal of electrocardiology.

[7]  B. Drew,et al.  Body position effects on the ECG: implication for ischemia monitoring. , 1997, Journal of electrocardiology.

[8]  O. Pahlm,et al.  Quantification of myocardial hypoperfusion with 99mTc-sestamibi in patients undergoing prolonged coronary artery balloon occlusion , 2002, Nuclear medicine communications.

[9]  R. Gibbons,et al.  Feasibility of tomographic 99mTc-hexakis-2-methoxy-2-methylpropyl-isonitrile imaging for the assessment of myocardial area at risk and the effect of treatment in acute myocardial infarction. , 1989, Circulation.

[10]  P Caminal,et al.  Automatic detection of wave boundaries in multilead ECG signals: validation with the CSE database. , 1994, Computers and biomedical research, an international journal.

[11]  H. White,et al.  Risk Stratification of Patients With Acute Anterior Myocardial Infarction and Right Bundle-Branch Block: Importance of QRS Duration and Early ST-Segment Resolution After Fibrinolytic Therapy , 2006, Circulation.

[12]  Pablo Laguna,et al.  QRS Slopes for Detection and Characterization of Myocardial Ischemia , 2008, IEEE Transactions on Biomedical Engineering.

[13]  G I Barbash,et al.  Prognostic significance of the admission electrocardiogram in acute myocardial infarction. , 1996, Journal of the American College of Cardiology.

[14]  G. Amit,et al.  Grade 3 ischemia on the admission electrocardiogram predicts failure of ST resolution and of adequate flow restoration after primary percutaneous coronary intervention for acute myocardial infarction. , 2007, American heart journal.

[15]  S. Traill,et al.  High frequency qrs electrocardiography in the detection of reperfusion following thrombolytic therapy , 1994, Clinical cardiology.

[16]  G S Wagner,et al.  Transient alterations of the QRS complex and ST segment during percutaneous transluminal balloon angioplasty of the left anterior descending coronary artery. , 1988, The American journal of cardiology.

[17]  G. Wagner,et al.  Effects of ischemic preconditioning and arterial collateral flow on ST-segment elevation and QRS complex prolongation in a canine model of acute coronary occlusion. , 2009, Journal of electrocardiology.

[18]  Raphaelf . Smith,et al.  Depolarization changes early in the course of myocardial infarction: significance of changes in the terminal portion of the QRS complex. , 1989, Journal of the American College of Cardiology.

[19]  A. Mager,et al.  Electrocardiographic classification of acute myocardial ischemia. , 1990, Israel journal of medical sciences.

[20]  H. White,et al.  Relationship of QRS duration at baseline and changes over 60 min after fibrinolysis to 30-day mortality with different locations of ST elevation myocardial infarction: results from the Hirulog and Early Reperfusion or Occlusion-2 trial , 2008, Heart.

[21]  O. Pahlm,et al.  Comparison of ST-segment deviation to scintigraphically quantified myocardial ischemia during acute coronary occlusion induced by percutaneous transluminal coronary angioplasty. , 2006, The American journal of cardiology.

[22]  E G DePuey,et al.  Technical aspects of myocardial SPECT imaging with technetium-99m sestamibi. , 1990, The American journal of cardiology.

[23]  C. Granger,et al.  Prediction of the extent and severity of left ventricular dysfunction in anterior acute myocardial infarction by the admission electrocardiogram. , 2001, American heart journal.

[24]  Charles Maynard,et al.  The value of both ST-segment and QRS complex changes during acute coronary occlusion for prediction of reperfusion-induced myocardial salvage in a canine model. , 2007, Journal of electrocardiology.

[25]  Olle Pahlm,et al.  Comparison of high-frequency QRS components and ST-segment elevation to detect and quantify acute myocardial ischemia. , 2010, Journal of electrocardiology.

[26]  A. Sinusas,et al.  Myocardial risk area defined by technetium-99m sestamibi imaging during percutaneous transluminal coronary angioplasty: comparison with coronary angiography. , 1993, Journal of the American College of Cardiology.