Distortion of the terminal portion of the QRS is predictor of shock after primary percutaneous coronary intervention for acute myocardial infarction.
BACKGROUND
Although invasive management of ST segment elevation myocardial infarction has improved the clinical outcome, cardiogenic shock (CS) remains an important issue. Our purpose was to asses the utility of the initial electrocardiogram in detecting patients who are at increased risk of CS after percutaneous coronary intervention for acute myocardial infarction.


METHODS
We evaluated 508 consecutive patients admitted in our Coronary Unit and treated by primary angioplasty within 12 h of an ST segment elevation myocardial infarction. Patients with cardiogenic shock at admission were excluded. Two groups were defined according to the presence of distortion of the terminal portion of the QRS in two or more adjacent leads (group 1) or the absence of this pattern (group 2).


RESULTS
There were 99 patients (20%) in group 1 and 409 (80%) in group 2. CS developed in 38 patients, 18 in group 1 (18%) and 20 in group 2 (5%), p<0.001. Seventeen patients died in hospital, 6 in group 1 (6%) and 11 in group 2 (3%), p 0.094. Multivariate analysis including clinical, electrocardiographic and angiographic variables showed distortion of the QRS as an independent predictor of cardiogenic shock (odds ratio 3.17, 95% confidence interval 1.44 to 6.96, p 0.004), together with Killip class at admission and TIMI 3 flow after revascularization.


CONCLUSIONS
Distortion of the terminal portion of the QRS complex is a strong predictor of cardiogenic shock in STEMI patients. Close hemodynamic monitoring should be warranted in patients showing this electrocardiographic pattern.
Garcia-Rubira
Juan C
JC
Instituto Cardiovascular, Hospital San Carlos, Madrid, Spain. drchjcgr@arrakis.es
Garcia-Borbolla
Rafael
R
Nuñez-Gil
Ivan
I
Manzano
Maria C
MC
Garcia-Romero
Maria M
MM
Fernandez-Ortiz
Antonio
A
Perez de Isla
Leopoldo
L
Macaya
Carlos
C
D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000379:methods* / Q000592:standards; D004562:Electrocardiography / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000628:therapy; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012770:Shock, Cardiogenic / Q000209:etiology* / Q000503:physiopathology*