The left ventricular end-systolic pressure-dimension relation in patients with thalassemia major. A new noninvasive method for assessing contractile state

SUMMARY Transfusion-dependent patients withthalassemia major(TM) are at an extremely highriskforcardiomyopathy. Traditional tests ofleft ventricular (LV)systolic function performed inthese patientsdo not distinguishderangements in loading conditionsfromabnormalitiesincontractilestate. Inthis study, we used the LV end-systolic pressure dimension (PES-DEs) relation, which is independent of preload,incorporatesafterloadandis highlysensitive to contractile state, to assess LV performancein20 asympto- matic, chronically transfusedpatients, ages 7-25 years, withTM.All patients had normalrestingsystolictimeintervalsand exerciseduration on treadmill. Baseline resting percentfractional shortening(%AD) on M-modeechocardiography(echo) was normalin 14 patients(group1) andabnormalinsix patients(group2). Echoandcarotidpulserecordings were made atrest andduringi.v. infusion of methoxamine to alter LV afterload. DE was measureddirectly fromecho; PES was estimatedfrom a calibratedcarotid pulsetracing.Thevalue for the slope ofthe