Heart failure during first inferior acute myocardial infarction

Background Inferior acute myocardial infarctions (AMI) have better in-hospi tal prognosis than do anterior AMI. Authors of several studies reported tha t patients with inferior AMI complicated by atrioventricular block, concomi tant precordial ST-segment depression and involvement of right ventricle ha ve larger infarctions and a worse prognoses than do patients without these features. Objective To analyse the incidence, clinical course and in-hospital prognos is of patients with heart failure and first inferior AMI. Methods We analysed in 257 consecutive patients with first inferior AMI who had been admitted to the coronary care unit during January 1991 and March 1995. The clinical and electrocardiographic characteristics, as well as the morbidities and in-hospital mortalities, of groups of patients with and wi thout heart failure during inferior AMI were compared. Results Symptoms and signs of heart failure were noted for 49 patients (19% ). We found that patients who had suffered heart failure during inferior AM I were older (61.1 +/- 9.86 versus 58.78 +/- 1 0.58 years, P<0.05) than tho se who had not suffered heart failure. There was no significant difference between patients' sex, history of diabetes mellitus, hypertension, smoking status, thrombolytic therapy, involvement of right ventricle and QRS score for these two groups. We found a greater prevalence of ST-segment depressio n (ST-segment depression greater than or equal to 1 mV in more than one pre cordial lead with maximal ST-segment depression in leads V4-V6) of V4-V6 pr ecordial leads (57 versus 26%, P=0.00002) and a lesser prevalence of no ST- segment depression (ST-segment depression <0.1 mV in each precordial lead; 14 versus 38%, P=0.001) among patients who had suffered heart failure. We f ound greater incidences of serious ventricular arrhythmias (53 versus 26, P =0.0002) and ventricular tachycardia-fibrillation (16 versus 7%, P=0.03) am ong patients who had suffered heart failure than we did among those who had not. Third-degree atrioventricular block was more often found in patients who had suffered heart failure (23 versus 12%, P=0.07) but this difference was not statistically significant. We found that the in-hospital mortality among patients who had suffered heart failure was much higher than that amo ng those who had not (24.5 versus 3.8%, P=0.000001). Conclusion We found that heart failure occurs primarily in old patients, an d in those with precordial ST-segment depression, especially in leads V4-V6 . The patients who suffer heart failure have worse in-hospital prognosis du e to serious ventricular arrhythmias and cardiogenic shock. Coronary Artery Dis 10:455-458 (C) 1999 Lippincott Williams & Wilkins.