Dyspnea in pregnancy might be related to the incomplete physiological adaptation of the heart

Introduction: Dyspnea is a common complaint in pregnant women with no cardiac and pulmonary diseases. We aimed to assess whether physiological dyspnea of pregnancy was correlated with subtle changes in ventricular systolic and diastolic function. Methods: This cross-sectional study enrolled 40 healthy pregnant women in their second and third trimesters with no complaints of dyspnea and 40 healthy pregnant women in the same trimesters with a complaint of dyspnea. Parameters of echocardiography were compared between the 2 groups. Results: Global left ventricular ejection fraction (59.65±6.44 and 58.49±4.95 P=0.418 in patients without and with dyspnea respectively), and global longitudinal strain were not significantly different (18.72±2.90 and 18.94±3.07, P=0.57 in the same order). Global circumferential strain(GCS)was lower in patients with dyspnea. ( 20.19±4.86 vs 22.61±4.69 ,P=0.03). Systolic volume (33.17±8.94 vs 32.63±8.09) and diastolic volume(80.75±18.73 vs 78.37±16.63) and left ventricular end-diastolic diameter(47.5±4.24 vs 46.23±3.21)were not different (P=0.784, 0.560 and 0.146 respectively) .Left ventricular end-systolic diameter was significantly lower in the case group (32.52±4.66 vs 29.92±4.05, P=0.011). Left atrial area index in the patients with dyspnea was lower.( 8.13±1.42 vs 8.94±1.4, P=0.014) . Other findings were a high E/E’ and high pulmonary artery pressure in the patients with dyspnea. Conclusion: Dyspnea in pregnant women can be a consequence of incomplete physiological adaptation to volume overload in pregnancy. Lower systolic and diastolic diameters of the left ventricle, left atrial area, and left atrial index may lead to increased filling pressure, manifested by a higher E/E’ ratio and pulmonary artery pressure.