CARDIOVASCULAR JOURNAL OF AFRICA • Volume 35, No 1, January – April 2024 48 AFRICA Ethnicity may cause variations in genetics and parameters of BSA and BMI and may directly influence echocardiographic measures. Therefore, correlation between ethnicity and RA volumetric parameters is important. In this study, there was a trend towards higher RAVI in males compared to females but no influence of age on RAVI was noted. The aforementioned finding was akin to the recent study by Nel et al.25 and the WASE study pertaining to RAVI in a normal population.16 Grünig et al. and D’Ascenzi et al. have shown that males had a larger RA area compared to females, explaining the volume differences between genders.27,28 D’Oronzio et al., Wang et al. and Peluso et al., using 2DE and 3DE, respectively, did not find any correlation between atrial volume and ageing, for reasons that are not fully understood.23,29,30 In the current study, the mean RALS was 32.7 ± 10.5%, which was lower than the value reported by Padeletti et al. and D’Ascenzi et al.22,28 In this Italian study comprising 84 and 74 subjects, RALS was documented using the 2D STE, and the mean RALS was 49 ± 13 and 48 ± 12.68%, respectively.22,28 These studies were done in a group of subjects with an overall lower BMI (22.4 ± 3.5 kg/m2), in contrast to our study (24–34.9 kg/ m2), and this is likely the explanation for higher RALS in their cohort. Obesity is a health problem of growing significance all over the world; its prevalence is increasing in both developed and developing countries. According to World Health Organisation data, 39% of the global population above 18 years of age are overweight and of these, 13% are obese. In Africa there is a significant trend towards obesity, with increments in BMI documented in both genders.31 Micklesfield et al. studied a South Africa population from Soweto and demonstrated a significant gender difference with regard to BMI, with women being markedly more overweight and obese.32 In our study, 67% of normal volunteers had a BMI above 25 kg/m2, which occurred more commonly in women (49%). BMI was the only independent predictor of RALS in this study. An inverse relationship was noted between BMI and RALS in the current study. A recent study by Chirinos et al. quantified LA strain and strain rate using STE in 1 531 middle-aged community-based participants enrolled in the Asklepios study. They demonstrated that longitudinal LA strain measured using STE decreased with elevated BMI.33 Obesity has been shown to have many effects on cardiovascular structure and function. Excess adiposity imposes an increased metabolic demand on the body and cardiac output. Total blood volumes are elevated in obesity, leading to a hyperdynamic circulation, which causes LV and RV structural changes, with the resultant increased ventricular mass and cavity dilatation. Obesity is the main cause of tissues fibrosis.34 Sokmen et al. and Csige et al. showed that uncomplicated obesity was associated with RV and RA dilatation, and increased thickness of the RV free wall. Also, these structural indices were found to be positively correlated with BMI. Myocardial fat accumulation as a consequence of obesity may cause atrial interstitial fibrosis and subsequently atrial dilatation and stiffness.35,36 This may be a possible mechanism explaining the inverse relationship between BMI and RALS in this study. Obesity may result in RA fibrosis, stiffness with a consequent reduction in myocardial deformation, and RALS. Furthermore, this study demonstrates that RALS tended to decrease with age and males tended to have higher values compared to females, although this finding did not reach statistical significance. Aging is associated with the development of myocardial fibrosis. Fibrotic tissue is stiffer and less compliant, resulting in subsequent cardiac dysfunction.37,38 We hypothesised that a combination of stiff RA and RV diastolic dysfunction associated with age-related myocardial fibrosis will have poor myocardial Table 3. Clinical and echocardiographic parameters of study participants according to gender Variables Total (n = 100) Males (n = 40) Females (n = 60) p-value* (ANOVA)# Clinical parameters Age (years) 37.5 (29.0–48.0) 34.0 (27.0–45.5) 39.0 (32.5–51.0) 0.055 Weight (kg) 73.0 (65.0–85.0) 68.0 (63.3–79.5) 79.0 (66.0–94.0) 0.016 Body mass index (kg/m2) 28.0 (24.0–34.9) 24.1 (22.5–29.6) 31.2 (26.6–37.8) < 0.001 Body surface area (m2) 1.8 ± 0.2 1.8 ± 0.1 1.8 ± 0.2 0.783 Systolic blood pressure (mmHg) 126.8 ± 12.4 127.2 ± 12.2 126.3 ± 12.5 0.737 Diastolic blood pressure (mmHg) 79.3 ± 10.3 78.5 ± 11.8 79.8 ± 9.3 0.535 Heart rate (bpm) 72.0 (62.5–82.0) 65.0 (59.0–76.5) 76.0 (67.0–82.5) 0.002 RA parameters RA volume (ml) 34.8 ± 10.7 37.0 ± 11.8 33.3 ± 9.5 0.090 RA volume index (ml/m2) 19.5 ± 5.7 20.8 ± 6.3 18.7 ± 5.2 0.070 RA width (mm) 36.3 ± 5.6 37.9 ± 6.0 35.2 ± 5.2 0.018 RA length (mm) 44.5 ± 5.2 44.2 ± 5.6 44.7 ± 4.9 0.679 RALS (%) 32.7 ± 10.5 34.6 ± 9.6 31.4 ± 10.9 0.141 RV functional parameters TAPSE (mm) 19.0 (17.0–22.0) 19.0 (17.0–22.0) 18.5 (17.0–21.5) 0.659 PASP (mmHg) 15.0 (13.5–20.0) 15.0 (12.0–17.0) 17.0 (15.0–20.0) 0.056 RV E′ (cm/s) 11.0 (8.9–13.0) 11.2 (9.0–12.9) 10.9 (8.6–13.2) 0.699 RV A′ (cm/s) 9.7 (8.4–12.1) 9.1 (8.4–11.7) 10.2 (8.7–12.8) 0.155 RV S′ (cm/s) 11.1 ± 2.1 10.9 ± 2.2 11.2 ± 1.9 0.406 RV base (mm) 31.0 (27.5–33.2) 31.6 (27.8–33.2) 30.3 (27.1–33.3) 0.499 RV E/A′ 1.1 (0.8–1.4) 1.0 (0.8–1.3) 1.1 (0.8–1.5) LV measurements LV systolic diameter (mm) 29.0 (26.0–31.5) 30.0 (27.5–32.0) 27.0 (25.5–30.0) 0.006 LV diastolic diameter (mm) 42.3 ± 5.1 44.2 ± 5.7 41.0 ± 4.2 0.001 End-diastolic volume index (ml/m2) 86.2 ± 23.1 94.5 ± 26.2 80.8 ± 19.2 0.003 End-systolic volume index (ml/m2) 18.2 (14.5–22.6) 16.9 (14.2–19.4) 19.8 (17.2–24.7) 0.012 LA volume index (ml/m2) 21.5 (15.2–26.4) 22.6 (16.1–28.0) 19.1 (13.3–24.6) 0.060 LA size (mm) 32.0 (28.0–35.3) 32.0 (28.3–34.0) 32.2 (27.8–36.6) 0.441 Ejection fraction (%) 62.5 ± 7.1 62.2 ± 7.8 62.7 ± 6.7 0.753 Posterior wall diameter (mm) 8.0 (7.0–9.5) 8.0 (7.0–9.5) 8.0 (7.0–9.5) 0.516 LV diastolic parameters E wave (cm/s) 80.6 ± 19.7 78.2 ± 16.1 82.2 ± 21.8 0.320 A wave (cm/s) 56.2 ± 15.1 50.3 ± 15.6 60.2 ± 13.5 0.001 E/A ratio 1.4 (1.1–1.8) 1.5 (1.2–1.9) 1.4 (1.1–1.4) 0.075 E′ medial (cm/s) 9.5 (7.5–11.8) 9.7 (7.9–12.0) 9.4 (7.1–11.5) 0.429 E′ lateral (cm/s) 13.4 ± 3.3 13.8 ± 3.0 13.1 ± 3.5 0.287 E/E′ lateral ratio 5.9 (5.0–7.0) 5.7 (5.0–6.8) 6.0 (5.0–7.1) 0.215 Data reported as means ± SD or median (IQR). IQR, interquartile range; LA, left atrial; PASP, pulmonary artery systolic pressure; RA, right atrial; RALS, right atrial longitudinal strain; RV, right ventricle; SD, standard deviation; TAPSE, tricuspid annular plane systolic excursion. #Independent t-test, p-value or Mann–Whitney test, p-value for non-normally distributed variables. *Statistical significance denoted by p-values < 0.05
RkJQdWJsaXNoZXIy NDIzNzc=