Prevalence of asymptomatic left ventricular systolic dysfunction in hypertensive Nigerians: echocardiographic study of 832 subjects

BACKGROUND

We sought to determine the prevalence of echocardiographically determined left ventricular systolic dysfunction in asymptomatic hypertensive subjects seen in Abeokuta, Nigeria.

METHODS

Echocardiography was performed in 832 consecutive hypertensive subjects referred for cardiac evaluation over a three-year period.

RESULTS

Data were obtained in 832 subjects (50.1% women) aged 56.0 ± 12.7 years (men 56.9 ± 13.3 years, women 55.0 ± 12.0 years, range 15-88). The prevalence of left ventricular systolic dysfunction (LVSD) was 18.1% in the study population (mild LVSD = 9.6%, moderate LVSD = 3.7% and severe LVSD = 4.8%). In a multivariate analysis, male gender, body mass index and LV mass were the predictors of LVSD.

CONCLUSION

Significant numbers of hypertensive subjects in this study had varying degrees of left ventricular systolic dysfunction. Early introduction of disease-modifying drugs in these patients, such as angiotensin converting enzyme inhibitors or angiotensin receptor blockers may retard or prevent the progression to overt heart failure.

[Suitability and performance of echocardiogram in primary care]

OBJECTIVE

The echocardiogram (ECC) is not available to all Spanish General Practitioners (GP) despite its proven benefits in prevalent diseases, such as hypertension and heart failure.

STUDY OBJECTIVE

To analyse the clinical adequacy of the application, performance, and diagnostic and therapeutic decisions of ECC indicated by the GP.

DESIGN

Descriptive, cross-sectional, retrospective, multicentre study.

SETTING

Primary care. Four health centres (HC).

PARTICIPANTS

A total of 684 patients over 18 years who had an ECC performed in 2006-2007.

MAIN MEASUREMENTS

A review of medical records and the ECC report. The socio-demographic variables, clinical and diagnostic performance were also evaluated.

RESULTS

The majority of patients (62.3%) were ≥ 65 years, of which 61.8% were female The most frequent reasons for performing ECC were (but not limited to): heart failure: 30%, suspected valvular disease: 26%; suspected cardiomyopathy: 24.3%. Adequacy of the ECC: 84% (95% CI: 81.09-86.7%) with differences by age (p=.02), HC teaching (p<.001), comorbidity (p<.001) and abnormal ECC (p<.001). A disease was found in 80% of ECC, with differences according to age (p<.001), comorbidity (p=0.02), cardiovascular risk factors (p<.001) and degree of appropriateness of ECC (p=.001). The most common findings (but not limited to) included: valvular heart disease (61.6%) left ventricular hypertrophy (43%) diastolic dysfunction (28.2%). The results of the ECC helped make decisions in 35.2%, with 17.1% referred to cardiology, 10.5% treatment change and 9.6% other tests.

CONCLUSIONS

We found that the application of ECC was highly appropriate. The results of ECC drive clinical decisions in a high percentage of cases. The ECC should be accessible to all GP.

Indexed left atrial volume is a more sensitive indicator of filling pressures and left heart function than is anteroposterior left atrial diameter

INTRODUCTION

Left atrial (LA) size is an indicator of the pressure to which it is chronically subjected. Although guidelines recommend measuring it using volume indexed to body surface, the anteroposterior diameter is still normally used.

AIM

To evaluate which of these measurements correlates better with atrial pressure-related echocardiographic parameters.

METHODS

Atrial diameter and volume, together with parameters of systolic function, diastolic function, pressure, and degree of mitral regurgitation, were measured in 121 consecutive outpatients.

RESULTS

Atrial diameter correlated with its indexed volume (r: 0.69) with a low degree of agreement for detecting dilation (Kappa: 0.51). Atrial diameter was related to the parameters associated with atrial pressure: E/E' (r: 0.44), pulmonary vein systolic/diastolic rates quotient (r: 0.25) and degree of mitral regurgitation (r: 0.19). The correlations improved when volume indexed to body surface was measured (r: 0.52; 0.38 and 0.44, respectively). In a multiple regression analysis that included E/E', pulmonary vein flow and degree of mitral regurgitation, LA diameter depended entirely on E/E' (r: 0.44; B: 0.04; P: 0.000). The relationship improved when the diameter was corrected for body surface or the volume was measured (r: 0.54 and 0.54, respectively), and in particular when volume indexed to body surface was measured (r: 0.66). In this case, pulmonary vein flow (B: 6.8; P: 0.03), degree of mitral regurgitation (B: 5.2; P: 0.000) and E/E' ratio (B: 0.8; P : 0.000) were included in the equation.

CONCLUSIONS

Indexed atrial volume correlates better with LA pressure surrogates than the anteroposterior diameter, even when this is corrected for body surface.