The impact of morbid obesity on cardiac structure and function in pregnancy

dc.contributor.advisorDyer, Robert A
dc.contributor.authorFernandes, Nicole Lucy
dc.date.accessioned2019-02-19T12:56:48Z
dc.date.available2019-02-19T12:56:48Z
dc.date.issued2018
dc.date.updated2019-02-19T11:56:21Z
dc.description.abstractBackground: The increasing prevalence of obesity worldwide is a major threat to global health. Structural and functional changes in the heart are well documented for obesity as well as for pregnancy, but there is limited literature on the impact of obesity on cardiac function in pregnancy. We hypothesized that cardiac maladaptation to pregnancy occurs more frequently in otherwise healthy morbidly obese pregnant women than in pregnant women of normal body mass index (BMI). Methods: This prospective cohort study was performed in two referral maternity units in Cape Town, South Africa, over a 3-month period. Forty morbidly obese pregnant women (BMI ≥40 kg.m⁻²) (Group O) were compared to 40 pregnant women of BMI 30 kg.m⁻² (Group N). Cardiac structure and function were assessed by transthoracic echocardiography, according to the recommendations of the British Society of Echocardiography. Results: Acceptable echocardiographic images were obtained in all obese women. Statistical significance was defined as P< .005 after applying the Bonferroni correction for multiple comparisons. Mean [SD] mean arterial pressure was higher in Group O (91 [8.42] vs 84 [9.49] mmHg, P<0.001). There were no between-group differences in heart rate, cardiac output, or cardiac index (84 [12] vs 79 [13] beats.min⁻¹, P=0.103; 5447 [1048] vs 4740 [1183] mL.min⁻¹, P=0.006; 2551 [474] vs 2729 [623] mL.min⁻¹.m⁻², P=0.156, respectively). Stroke volume index was lower, and left ventricular mass higher in Group O (30.14 [4.51] vs 34.25 [7.00] mL.m⁻², P=0.003; 152 [24] vs 115 [29] g, P<0.001). Isovolumetric relaxation time was significantly prolonged in Group O (73 [15] vs 61 [15] milliseconds, P<0.001). The septal tissue Doppler index E' sept was lower in Group O (9.08 [1.69] vs 11.28 [3.18], P<0.001). There were no between- group differences in E' average (10.7 [2.3] vs 12.0 [2.7], P=0.018), or E/E' average (7.85 [1.77] vs 7.27 [1.68]). Conclusion: Obese pregnant women had a similar cardiac output and cardiac index to those with normal BMI. Their increased left ventricular mass and lower stroke volume index could indicate a limited adaptive reserve. Obese women had minor decreases in septal left ventricular tissue Doppler velocity, but the E/E' average values did not suggest clinically significant diastolic dysfunction.
dc.identifier.apacitationFernandes, N. L. (2018). <i>The impact of morbid obesity on cardiac structure and function in pregnancy</i>. (). University of Cape Town ,Faculty of Health Sciences ,Department of Anaesthesia and Perioperative Medicine. Retrieved from http://hdl.handle.net/11427/29661en_ZA
dc.identifier.chicagocitationFernandes, Nicole Lucy. <i>"The impact of morbid obesity on cardiac structure and function in pregnancy."</i> ., University of Cape Town ,Faculty of Health Sciences ,Department of Anaesthesia and Perioperative Medicine, 2018. http://hdl.handle.net/11427/29661en_ZA
dc.identifier.citationFernandes, N. 2018. The impact of morbid obesity on cardiac structure and function in pregnancy. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Fernandes, Nicole Lucy AB - Background: The increasing prevalence of obesity worldwide is a major threat to global health. Structural and functional changes in the heart are well documented for obesity as well as for pregnancy, but there is limited literature on the impact of obesity on cardiac function in pregnancy. We hypothesized that cardiac maladaptation to pregnancy occurs more frequently in otherwise healthy morbidly obese pregnant women than in pregnant women of normal body mass index (BMI). Methods: This prospective cohort study was performed in two referral maternity units in Cape Town, South Africa, over a 3-month period. Forty morbidly obese pregnant women (BMI ≥40 kg.m⁻²) (Group O) were compared to 40 pregnant women of BMI 30 kg.m⁻² (Group N). Cardiac structure and function were assessed by transthoracic echocardiography, according to the recommendations of the British Society of Echocardiography. Results: Acceptable echocardiographic images were obtained in all obese women. Statistical significance was defined as P< .005 after applying the Bonferroni correction for multiple comparisons. Mean [SD] mean arterial pressure was higher in Group O (91 [8.42] vs 84 [9.49] mmHg, P<0.001). There were no between-group differences in heart rate, cardiac output, or cardiac index (84 [12] vs 79 [13] beats.min⁻¹, P=0.103; 5447 [1048] vs 4740 [1183] mL.min⁻¹, P=0.006; 2551 [474] vs 2729 [623] mL.min⁻¹.m⁻², P=0.156, respectively). Stroke volume index was lower, and left ventricular mass higher in Group O (30.14 [4.51] vs 34.25 [7.00] mL.m⁻², P=0.003; 152 [24] vs 115 [29] g, P<0.001). Isovolumetric relaxation time was significantly prolonged in Group O (73 [15] vs 61 [15] milliseconds, P<0.001). The septal tissue Doppler index E' sept was lower in Group O (9.08 [1.69] vs 11.28 [3.18], P<0.001). There were no between- group differences in E' average (10.7 [2.3] vs 12.0 [2.7], P=0.018), or E/E' average (7.85 [1.77] vs 7.27 [1.68]). Conclusion: Obese pregnant women had a similar cardiac output and cardiac index to those with normal BMI. Their increased left ventricular mass and lower stroke volume index could indicate a limited adaptive reserve. Obese women had minor decreases in septal left ventricular tissue Doppler velocity, but the E/E' average values did not suggest clinically significant diastolic dysfunction. DA - 2018 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2018 T1 - The impact of morbid obesity on cardiac structure and function in pregnancy TI - The impact of morbid obesity on cardiac structure and function in pregnancy UR - http://hdl.handle.net/11427/29661 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/29661
dc.identifier.vancouvercitationFernandes NL. The impact of morbid obesity on cardiac structure and function in pregnancy. []. University of Cape Town ,Faculty of Health Sciences ,Department of Anaesthesia and Perioperative Medicine, 2018 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/29661en_ZA
dc.language.isoeng
dc.publisher.departmentDepartment of Anaesthesia and Perioperative Medicine
dc.publisher.facultyFaculty of Health Sciences
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherAnaesthesiology
dc.titleThe impact of morbid obesity on cardiac structure and function in pregnancy
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMMed
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