title: [Changes in the electrocardiogram in status asthmaticus].
abstract: The aim of this study, based on the electrocardiographic analysis of 42 patients in status asthmaticus, is to define the basic criteria which may be used as a basis for electrocardiographic differential diagnosis. The following ECG changes were observed: the pulmonary "p" wave is common, sometimes with exaggerated amplitude in peripheral leads, however, in the precordial leads, the voltage of the "p" wave is reduced; most cases have a vertical heart with clockwise rotation and mild right axis deviation, S1 Q2 Q3 and the transitional zone displaced to the left. Ten cases also had a S1 S2 S3 appearance and three cases showed Q1 Q2 Q3, simulating myocardial infarction; there is poor progression of the R wave in the precordial leads and marked persistence of the S wave in the left precordial leads. In some cases, a QS complex dominates the right precordial leads. A variation in the amplitude of the QRS with the respiratory rhythm is often seen in V1 and V2; ventricular repolarization shows a lowered J point with an upward oblique ST segment in the peripheral leads. However, in the precordial leads, the repolarization is normal except for three cases which presented a frank hypokalaemia. The mechanism of these electrocardiographic changes appears to depend on the vertical position of the heart caused by over expansion of the lungs and pulmonary arterial hypertension. The elements of the electrocardiographic differential diagnosis with myocardial infarction and pulmonary embolism are discussed.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000175:diagnosis / Q000503:physiopathology*; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis; D011655:Pulmonary Embolism / Q000175:diagnosis; D011660:Pulmonary Heart Disease / Q000175:diagnosis*
vernacular_title: Les modifications de l'électrocardiogramme dans l'état de mal asthmatique.