[The value of temporary electrosystolic pacing for treating low output in posterior necrosis with adiastole]

Early catheterisation was performed in 27 patients with an acute inferior myocardial infarction less than 3 days old complicated by signs of low output with right ventricular dysfunction. All patients had hemodynamic criteria of adiastole (PCP = 14.9 +/- 31 mmHg and LVEDP = 14.1 +/- 4.7 mmHg) with low cardiac output (CI = 1.41 +/- 0.32 l/min/m2). An atropine resistant bradycardia was characteristic (HR = 65 +/- 17.2/min) due to advanced or complete AV block (11 cases), sinoatrial block (3 cases, one with right atrial standstill) or sinus/parasinus rhythm (13 cases) inappropriate to the severity of their hemodynamic state. Although the prognosis based on the discriminating linear function FI = -0.427 + 0.00121 LVW - 0.00125 TPR was initially poor and predicted the death of 21 out of the 27 patients at one month, the outcome was usually favourable and only 8 patients died during the first month. Fifteen patients were treated by temporary endocavitary RV pacing. As the heart rate was increased from 53.8 +/- 11.2 to 92.4 +/- 4.9/min, the CI rose from 1.35 +/- 0.26 to 1.85 +/- 0.46 l/min/m2 (p less than 0.001) with a fall in SI from 26.7 +/- 8.3 to 20.1 +/- 5.6 ml/beat/m2 (p less than 0.005). The results were even further improved in 3 cases by sequential A-V pacing. The observed hemodynamic improvement continued during the period of pacing providing volumic expansion maintained LVEDP above 10 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)