EARLY CHANGES OF LEFT ATRIAL VOLUME IN YOUNG PREHYPERTENSIVE SUBJECTS SEEN IN USMANU DANFODIYO UNIVERSITY TEACHING HOSPITAL, SOKOTO.

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1 EARLY CHANGES OF LEFT ATRIAL VOLUME IN YOUNG PREHYPERTENSIVE SUBJECTS SEEN IN USMANU DANFODIYO UNIVERSITY TEACHING HOSPITAL, SOKOTO. 1 Oboirien IO, 2 Hayatu U, 2 Zagga MU, 2 Omoniyi ON, 3 Sani MU, 2 Isezuo SA. 1 Department of Medicine, Dalhatu Araf Specialist Hospital, Lafia, Nasarawa. 2 Department of Medicine, Usmanu Danfodiyo University Teaching Hospital, Sokoto. 3 Department of Medicine, Aminu Kano Teaching Hospital, Kano.

2 CONFLICT OF INTEREST NONE WAS DECLARED

3 INTRODUCTION The relationship between BP and risk of cardiovascular disease events is continuous, consistent, and independent of other risk factors. Left atrial enlargement is a documented finding at diagnosis of hypertension. There are reports that these findings may predate onset of hypertension. Left atrial size is more accurately reflected by measurement of volume rather than a linear dimension. This provides a more accurate estimate of LA size, especially if it is indexed to body surface area.

4 AIM Comparison of left atrial volumes in prehypertensives with age and sex matched normotensives.

5 METHODS This was a cross-sectional-descriptive study carried out in Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria. 150 Prehypertensive and 150 Normotensive subjects were consecutively recruited. Baseline demographic biodata were measured. Echocardiography derived left atrial volumes (LAV) were assessed through standardised methods. Left atrial area was measured from two orthogonal apical views (apical four (A 1 ) and two (A 2 ) chamber views).

6 The length (L) was measured as a distance of the perpendicular line measured from the middle of the plane of mitral annulus to the superior aspect of the LA LAV was determined using area length method based on ASE guidelines using the formula; LAV = 0.85 (A 1 ) (A 2 ) / L Where: A 1 = LA area in apical four chamber view A 2 = LA area in apical two chamber view L = LA length (the shortest of the two lengths was used in the calculation). Left atrial volume index was calculated as LAV/ BSA (ml/m 2 )

7 RESULTS 150 Prehypertensive and 150 Normotensive subjects were consecutively recruited. They were matched for age (28.14±3.11 vs 28.43±3.26, P=0.642) and sex (Male:Female = 1.2:1 in both groups).

8 Clinical and Echocardiographic Characteristics Parameters Prehypertensives (N=150) Normotensives(N=150) t P Value Mean (SD) Mean (SD) Age (Years) 28.14(3.11) 28.43(3.26) Height (cm) 1.670(0.076) 1.667(0.072) Weight (kg) 73.22(10.68) 61.75(7.92) Waist Circumference (cm) 87.02(8.78) 76.64(6.58) <0.001 BMI (Kg/m 2 ) 26.27(3.47) 22.18(2.16) <0.001 SBP (mmhg) (3.54) (3.55) <0.001 DBP (mmhg) 79.37(4.20) 66.36(4.47) <0.001 Aortic Root (mm) 29.90(2.26) 28.52(2.08) Left Atrial Volume Index (ml/m 2 ) 21.29(1.54) 19.00(1.07)

9 Correlates of left atrial volume index in Prehypertensives Parameters r P Value Age <0.001 Waist Circumference <0.001 BMI <0.001 SBP <0.001 DBP Aortic Root Dimension <0.001 LVPWD <0.001 LVIDD LVMI 0.40 <0.001

10 Correlates of left atrial volume index in Prehypertensives Parameters r P Value LV Ejection Fraction Fractional Shortening Transmitral E Velocity <0.001 Transmitral A Velocity E/A Ratio <0.001 Mitral Annulus E Velocity <0.001 Mitral Annulus A Velocity E/E Deceleration Time <0.001 Isovolumetric Relaxation Time <0.001

11 Factors associated with LAVI on simple regression analysis in Prehypertensive Subjects Parameter Odds Ratio P Value 95% CI Age LVMI Waist Circumference BMI SBP DBP Aortic Root Dimension (mm) LVPWD LVIDD

12 Deceleration Time Factors associated with LAVI on linear regression analysis in Prehypertensive Subjects Parameter Odds Ratio P Value 95% CI Regional Wall Thickness Transmitral E Velocity Transmitral A Velocity E/A Ratio Mitral Annulus E Velocity Mitral Annulus A Velocity E/E Isovolumetric Relaxation Time

13 DISCUSSION Left atrial enlargement has been suggested to be an initial step before the onset of atrial fibrillation in Hypertension. This study demonstrated a significantly higher left atrial volume in prehypertensive subjects compared to normotensives. This finding is similar to earlier reports by Arturk et al and Eweda et al in Turkey and Egypt respectively. The left atrial volume index (LAVI) was normal in both prehypertensive and normotensive subjects. However the mean LAVI in the prehypertensive subjects was closer to the upper limit of normal compared to the normotensive subjects.

14 Jang et al findings were similar in a study amongst middle aged Korean population. However the mean LAVI in that study was higher compared to this study (26.6±6.6ml/m 2 vs 21.29±1.54ml/m 2 ). This may be because Jang et al studied an older population ( 53.7±5.2 years vs 28.14±3.11 years). There has been reports of the relationship between blood pressure and left atrial size. Vaziri et al from the Fragminham Heart Study and Galdensi et al showed an association between blood pressure and left atrial size. This study also demonstrated an association between blood pressure and left atrial size. This study showed that age, left ventricular mass and aortic root size were independent determinants of left atrial size. Adebiyi et al in a study in Ibadan also revealed that age and left ventricular mass influence left atrial size amongst hypertensives.

15 CONCLUSION Left atrial volume is significantly higher in prehypertensive subjects compared to normotensive subjects Early atrial remodeling in young prehypertensive subjects probably predates left atrial enlargement seen in hypertensives. Left atrial size in young prehypertensive subjects is influenced by age, left ventricular mass and aortic root size.

16 REFERENCES Adebiyi A, Aje A, Ogah OS, Ojji D, Dada A, Oladapo OO, Falase OA. Correlates of left atrial size in Nigerian hypertensives. Cardiovascular Journal of South Africa. 2005;16: Arturt E, Ermis N, Yagmur J, Acikgoz N, Kurtoglu E, Lansel M, et al. Early left atrial mechanics and volume abnormalities in subjects with prehypertension: A real time Three-dimensional echocardiography study. Journal of Cardiovascular Ultrasound and allied techniques. 2012;29: Eweda I, El-Meniawy K, Sakr M, Nammas W. Early changes of left atrial volumes and function in subjects with prehypertension: A cross-sectional study. European Journal of Cardiovascular Medicine. 2017;5: Galderisi M, Petrocelli A, Fakher A, Izzo A, Alfieri A, Divitis O. Influence of nighttime blood pressure on left atrial size in uncomplicated arterial systemic hypertension. American Journal of hypertension. 1997;10: Eweda I, El-Meniawy K, Sakr M, Nammas W. Early changes of left atrial volumes and function in subjects with prehypertension: A cross-sectional study. European Journal of Cardiovascular Medicine. 2017;5: Galderisi M, Petrocelli A, Fakher A, Izzo A, Alfieri A, Divitis O. Influence of nighttime blood pressure on left atrial size in uncomplicated arterial systemic hypertension. American Journal of hypertension. 1997;10:

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