[Significance of ST segment depression in the precordial leads during the acute phase of inferior myocardial infarction].

Reciprocal changes of the ST segment in the acute phase of inferior myocardial infarction are common but their significance remain controversial. We studied this problem by comparing the ECG on admission of 83 patients with acute inferior myocardial infarction, with the clinical outcome and haemodynamic and angiographic data obtained on average 3 weeks after the onset of symptoms. Fifty nine patients (Group I) had ST depression greater than or equal to 1 mm in at least one of the leads V1 to V4; 24 patients (Group II) had no ST depression in this territory. The patients in Group I were older (59.6 +/- 6.4 vs 54 +/- 5.3 years, p less than 0.01), had higher total CPK (1 835 +/- 940 vs 875 +/- 305, p less than 0.01) and MB fractions (269 +/- 102 vs 95 +/- 35), more complications during the hospital period (80%, mainly haemodynamic vs 38%, p less than 0.01) and more severe left ventricular dysfunction: ejection fraction 52.2 +/- 6% vs 59.2 +/- 7%, p less than 0.05; cardiac index 2.75 +/- 0.4 l/min/m2 vs 3.25 +/- 0.3 l/min/m2, p less than 0.005). There was no difference in left ventricular wall motion between the groups on biplane angiography. However, coronary angiography showed left coronary disease to be more common in Group I (84%) than in Group II (37%), p less than 0.005. Left anterior descending and left circumflex disease was equally common. Patients with persistent ST depression after 48 hours had lower ejection fractions than those in whom it regressed within 48 hours.(ABSTRACT TRUNCATED AT 250 WORDS)