Resultado

Note: Este modelo predictivo se usará solamente como ayuda y debe ser aplicado teniendo en cuenta otros datos de juicio sobre el paciente.

Algoritmo para determinar la presencia de IAM en pacientes con dolor precordial y BRI

Pregunta

Si

No

Respuesta

ST seg. elev. >= 1mm y si es concordante con el eje del QRS

+5

+0

Y

Y

Y

Y

N

N

N

N

ST seg. depr. >= 1mm in V1, V2, or V3

+3

+0

Y

Y

N

N

Y

Y

N

N

ST seg. elev. >= 5mm y si es discordante con el eje del QRS

+2

+0

Y

N

Y

N

Y

N

Y

N

 

Escore:

10

8

7

5

5

3

2

0

%IAM:

100

92

93

88

100

66

50

16

Pacientes/Controles:

4/0

22/2

26/2

43/6

1/0

6/3

9/9

20/109

Abreviaciones:
Y = Si;
N = No;
ST seg. depr. = depresión del segmento ST;
ST seg. elev. = elevación del segmento ST.


Valor predictivo del ECG en pacientes con un escore total >= 3

escore total >= 3

Muestra de derivación
(N = 262)

Muestra de validación
(N = 45)

Sensibilidad (%)

78

36

Especificidad (%)

90

96

Valor predictivo positivo(%)

89

88

Valor predictivo negativo(%)

80

61


Referencia:

Sgarbossa and colleagues found that only the electrocardiographic criteria above were of independent value in predicting AMI in the presence of LBBB. Their algorithm assigns a point score to each positive finding on the basis of its odds ratio, and then uses the combined score to determine the likelihood of MI. Using ECG to rule in MI speeds diagnosis, allowing for more effective use of coronary reperfusion therapies.


Resumen de la fuente:

Sgarbossa EB, Pinski SL, Barbagelata A, et al: Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. N Engl J Med 334(8):481-7, 1996 Feb 22.

BACKGROUND. The presence of left bundle-branch block on the electrocardiogram may conceal the changes of acute myocardial infarction, which can delay both its recognition and treatment. We tested electrocardiographic criteria for the diagnosis of acute infarction in the presence of left bundle-branch block.
METHODS. The base-line electrocardiograms of patients enrolled in the GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) trial who had left bundle-branch block and acute myocardial infarction confirmed by enzyme studies were blindly compared with the electrocardiograms of control patients who had chronic coronary artery disease and left bundle-branch block. The electrocardiographic criteria for the diagnosis of infarction were then tested in an independent sample of patients presenting with acute chest pain and left bundle-branch block.
RESULTS. Of 26,003 North American patients, 131 (0.5 percent) with acute myocardial infarction had left bundle-branch block. The three electrocardiographic criteria with independent value in the diagnosis of acute infarction in these patients were an ST-segment elevation of 1 mm or more that was concordant with (in the same direction as) the QRS complex; ST-segment depression of 1 mm or more in lead V1, V2, or V3; and ST-segment elevation of 5 mm or more that was disconcordant with (in the opposite direction from) the QRS complex. We used these three criteria in a multivariate model to develop a scoring system (0 to 10), which allowed a highly specific diagnosis of acute myocardial infarction to be made.
CONCLUSIONS. We developed and validated a clinical prediction rule based on a set of electrocardiographic criteria for the diagnosis of acute myocardial infarction in patients with chest pain and left bundle-branch block. The use of these criteria, which are based on simple ST-segment changes, may help identify patients with acute myocardial infarction, who can then receive appropriate treatment.

Regresar al calculador

Hospital Regional Ushuaia - Centro Médico Fueguino - ¡Vivir Mejor!
Buscadores - Medline - Ubicación del site