title: [Factors influencing the development of low output state in patients with right ventricular infarction].
abstract: Right ventricular infarction is frequently accompanied by a low output state, but the factors influencing the development of this state remain unknown. To elucidate these factors, clinical findings, hemodynamic findings and left ventricular infarct size (T1-score) calculated from thallium-201 myocardial scintigrams by a circumferential profile method were evaluated in 147 consecutive patients with acute transmural inferior myocardial infarction. They were divided into two groups: 44 patients with right ventricular involvement (RVI group) and 103 patients without right ventricular involvement (IMI group). A low cardiac output state was defined when the cardiac index was less than 2.2 L/min/M2. There was a good correlation between T1-score and any of peak value of serum creatine phosphokinase (CPKmax), total released CPK (CPKr) and left ventricular ejection fraction (LVEF) (r = 0.66, 0.74 and -0.54, respectively), indicating the usefulness of T1-score as an index of left ventricular damage. Compared to the IMI group, the RVI group showed a higher average of age (p less than 0.01), lower systemic blood pressure (p less than 0.01), higher right atrial pressure (p less than 0.001) and lower cardiac index (p less than 0.01). Furthermore, the incidence of a low output state (RVI group : 47.7% vs IMI group : 14.6%, p less than 0.001) and mortality (25.0% vs 7.8%, p less than 0.01) were higher in the RVI group. However, CPKmax, CPKr, LVEF and T1-score, which were considered to reflect the severity of left ventricular damage, were not different between the two groups. T1-score was inversely correlated with cardiac index in the RVI group (r = -0.49, p less than 0.05), and with left ventricular stroke work index in the both groups (RVI group; r = -0.46, p less than 0.01, IMI group; r = -0.64, p less than 0.01). Additionally, age as well as heart rate was correlated significantly with cardiac index (r = -0.45, p less than 0.001 and r = 0.35, p less than 0.001, respectively), and the percentage of elderly patients (age greater than 60 years) and the incidence of bradycardia (heart rate less than 60/min) were both higher in the RVI group than the IMI group (either p less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)
mesh_terms: D000367:Age Factors; D001794:Blood Pressure; D002303:Cardiac Output, Low / Q000209:etiology*; D003402:Creatine Kinase / Q000097:blood; D006352:Heart Ventricles; D006439:Hemodynamics; D006801:Humans; D009203:Myocardial Infarction / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D011877:Radionuclide Imaging; D013318:Stroke Volume
chemical_list: D003402:Creatine Kinase