Effects of dipper and non-dipper status of essential hypertension on left atrial mechanical functions
Introduction
Left atrium (LA) has an important supplement in left ventricular output volume. Left ventricular filling is maintained by LA reservoir function during ventricular systole, and LA passive conduit function during early diastole and active contractile function during late diastole with the presence of normal sinus rhythm [1], [2], [3], [17]. It is well known that essential hypertension deteriorates LA functions [3]. Blood pressure (BP) is characterized by alteration of rhythm along 24 h in hypertensive patients [4]. Mean BP values reveal 10–20% lower values in the night, compared to daytime measurements. This condition is called “dipper”' change. But in some hypertensives, contrary to this normal change, nighttime BP lowering does not occur or shows a decrease less than 10% which is called “non-dipper” change [5]. It is known that target organ injury occurs more severe in non-dipper hypertensive patients than in dipper status of hypertension (DH) and non-dipper status of hypertension (NDH) itself is a risk factor increasing the mortality [6], [7]. The most commonly used noninvasive technique to evaluate LA performance is Doppler echocardiography. However, Doppler echocardiography is limited since it provides no information about LA size. Although the use of this technique to evaluate LA booster pump function has been described, it is not suitable for the assessment of reservoir and conduit phases of LA function. Measurement of LA volumes at different phases of the cardiac cycle was proven to be useful for evaluating LA performance [15]. According to our knowledge, the effects of DH and NDH on left atrial reservoir, conduit, and booster pump functions have not been investigated in hypertensive patients. Therefore, this study was designed in order to investigate the effects of dipper and non-dipper status of hypertension on left atrial mechanical functions with left atrial volume measurements by means of two-dimensional echocardiography in untreated systemic hypertensive patients.
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Study groups
The study population consisted of group I, 27 untreated dipper essential hypertensive (15 female, 12 male, mean age: 57±12years); group II, 23 untreated non-dipper essential hypertensive patients (12 female, 11 male, mean age; 53±18 years) and group III, 25 volunteers (13 female,12 male, mean age: 53±10 years) without evidence of cardiovascular disease served as age matched healthy subjects. All patients were in sinus rhythm. None of the patients was receiving anti-hypertensive drugs at the
Statistical analysis
All data are expressed as mean±S.D. echocardiographic parameters of both hypertensive patients and control group. Statistical analyses were performed with a commercially available SPSS 9.0 statistics programme (SPSS, Chicago, IL, USA). Differences among groups were assessed with the chi-square test for categorical variables. Comparisons among groups were made using one-way factorial analysis of variance, followed by the Scheffé test. Relationship between various variables were examined with
Results
Clinical characteristics, M-Mode and two-dimensional echocardiographic measurements are listed in Table 1. The number of patients, male to female ratio, the value of body surface areas were similar to hypertensive groups and the controls. During echocardiogram, the systolic, diastolic blood pressure and pulse pressure were similar in DH and NDH in hypertensive patients. No difference in heart rate was found among the three groups at the time of the echocardiogram. The measurements of left
Discussion
Left atrial (LA) functions consist of reservoir, conduit and booster pump functions at different stages of cardiac cycle. Left atrial reservoir functions occur during ventricular systole, passive conduit function occur in early diastole and booster pump function occur during ventricular diastole in the presence of sinus rhythm. The importance of LA mechanical emptying function increases in patients with left ventricular dysfunction, aortic stenosis, hypertrophic obstructive cardiomyopathy and
Conclusion
Our findings indicate that atrial reservoir and booster pump functions increase in hypertensive patients but this result is more prominent in non-dipper hypertensives than in dipper hypertensive patients.
References (27)
- et al.
Influence of left ventricular dysfunction on the role of atrial contraction
J. Am. Coll. Cardiol.
(2000) - et al.
Echocardiographic features of left atrium in elite male athletes
Am. J. Cardiol.
(1996) - et al.
Standardization of M-mode echocardiographic left ventricular anatomic measurements
J. Am. Coll. Cardiol.
(1984) - et al.
Left atrial mechanical function in the healthy elderly: new insights from a combined assessment of changes in atrial volume and transmitral flow velocity
J. Am. Soc. Echocardiogr.
(1995) - et al.
Left ventricular function, cardiac dysrhythmias, atrial activation, and volumes in non-dipper hypertensive individuals with left ventricular hypertrophy
Am. Heart J.
(2000) - et al.
Influence of night-time blood pressure on left atrial size in uncomplicated arterial systemic hypertension
Am. J. Hypertens.
(1997) - et al.
Cardiovascular abnormalities in never-treated hypertensives according to non-dipper status
Am. J. Hypertens.
(1998) - et al.
Effects of postural changes on left atrial function in patients with hypertrophic cardiomyopathy
Am. Heart J.
(1998) - et al.
A clinic appraisal of left atrial function
Eur. Heart J.
(2001) - et al.
Contribution of atrial reservoir function to ventricular filling in hypertensive patients
Hypertension
(1995)
Twenty-four-hour ambulatory blood pressure in men and women aged 17 to 80 years: the allied Irish bank study
J. Hypertens.
Dippers versus non-dippers
J. Hypertens.
The clinical significance of diurnal blood pressure variations. Dippers and non-dippers
Circulation
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