Left ventricular diastolic function during uncomplicated pregnancy

Background and objective: During pregnancy many substantial changes occur i n the cardiovascular system. Aim of this study was to examine how physiolog ical preload alterations influence left ventricular haemodynamic parameters . Patients and methods: During the 9th, 24th and 33rd weeks of pregnancy and 8 weeks after childbirth 36 patients underwent echocardiographic studies. 3 6 young not pregnant women (25+/-7 years) served as controls. The following Dopplerechocardiographic parameters were measured: peak early diastolic fl ow velocity (VE, ms); acceleration (AT; ms) and deceleration time (DT; ms) of flow velocity in early diastole; peak late diastolic flow velocity (VA; mis) and isovolumetric relaxation time (IVRT; ms). In all women the left ve ntricular muscle mass index (LVMMI), fractional shorting (FS; %) and the ra tio between septum and posterior ventricular wall were calculated. Results: During pregnancy all women showed an elevation of the left ventric ular muscle mass index (LVMMI: from 66 +/- 6 to 100 +/- 9 g/m(2); p<0.01) a nd a decrease of fractional shortening (FS: from 38 +/- 4 to 31 +/- 3 %). A ll patients developed a relevant diastolic dysfunction: reduced early diast olic flow velocity (VE: from 0,89 +/- 0,11 to 0,83 +/- 0,19 mis; P < 0,01), reduced EIA ratio (1,7 +/- 0,4 to 1,2 +/- 0,4; P<0,01), prolonged IVRT (72 +/- 12 to 114 +/- 12 ms; P < 0,01) and deceleration time (DT: to 189 +/- 1 7 to 227 +/- 18 ms; P<0,01). Eight weeks after childbirth all parameters of left ventricular systolic and diastolic functions were normal. Conclusion: Preload alterations during normal pregnancy lead to reversible physiological left ventricular hypertrophy. Furthermore, we found a short-t i me reduction of systolic function just before childbirth and a significan t alteration of the left Ventricular diastolic filling pattern (abnormal re laxation pattern). While left ventricular systolic function was normal in a ll patients one week after child birth, left ventricular hypertrophy and le ft ventricular diastolic dysfunction persisted for nearly two months.