Systolic time intervals in chronic anemia.
Systolic time intervals were measured noninvasively in 12 healthy control subjects (hemoglobin 12 to 15 Gm. per cent) and 32 cases of chronic anemia without underlying cardiovascular disease. It was found that in mild anemia (hemoglobin above 7 Gm. per cent), where cardiac output is known to be normal, the systolic time intervals were also normal. In severe anemia (hemoglobin below 7 Gm. per cent), where cardiac output is known to be high, the systolic time intervals showed the pattern usually associated with high cardiac output, i.e., increased left ventricular ejection time (LVET) and decreased pre-ejection period (PEP) and PEP/LVET ratio, only when congestive failure was absent. In severe anemia with congestive failure, the LVET was decreased, and PEP and PEP/LVET ratio were increased--the pattern associated with impaired myocardial performance, even though cardiac output is known to be high in such cases also.