Disparity between diastolic mitral flow characteristics and left ventricular mass in essential hypertension

S, A.K. A, A.K. D, Garg B, Goel A. Impact of prehypertension on left ventricular structure, function and geometry

BACKGROUND

Awareness of prevalence, determinants, and prognosis of asymptomatic untreated prehypertension is still lacking especially in India and subcontinent. The present study was to assess the effects of prehypertension on structure, function and geometrical pattern of left ventricle on the basis of left ventricular mass (LVM), left ventricular mass indexed to height (LVMI/Ht), and relative wall thickness (RWT) recorded by echocardiography based on the American society of echocardiography (ASE) convention.

METHODS

The study population included prehypertensives (n 61; 31 M, 30 F) and normotensives (n 38; 19 M, 19 F) between age 25 and 65 years, and were assessed by echocardiography.

RESULTS

It was observed that the stroke volume (SV), cardiac output (CO), cardiac index (CI), body mass index (BMI), body surface area (BSA), were found to be little elevated but was not significant in hypertensive females compared to normotensives. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), pulse pressure (PP), mean arterial pressure (MAP), end systolic stress (ESS), and end isovolumetric systolic stress (EISS) were significantly elevated (p<0.001) in female prehypertensives compared to normotensives. Left ventricular mass (LVM) was significantly (p< 0.05) elevated, indicating alterations in cardiac morphology and functions even during prehypertensive stage. However, in prehypertensive males, SBP, DBP, HR, PP, MAP, ESS, and EISS were significantly (<0.001) raised; ejection fraction (EF%) and fractional fibre shortening (FS%) were noted to be within normal range in both sexes. Prehypertensive males showed changes in left ventricular geometry in the form of concentric remodeling (CR-3.44%), eccentric hypertrophy (EH-3.44%) and concentric hypertrophy (CH-13.79%). Prehypertensive females showed (CR-6.45%), (EH-3.22%) and (CH-6.4%).

CONCLUSION

Such findings carry prognostic implication and require further population survey involving a larger group. Early diagnosis of prehypertension will help to take necessary preventive measures to reduce mainly the future cardiovascular complications. The care of prehypertensive subjects should include, to reduce the afterload in order to improve the left ventricular contractile state as early as possible. So it is advisable to do routine echocardiography after the age of 40 years.

Different pattern of carotid and myocardial changes according to left ventricular geometry in hypertensive patients

The relation between left ventricular (LV) hypertrophy and LV function is well known. However, less is known about the vascular changes influenced by LV geometry. We sought to investigate the relationship of LV geometry to carotid arterial and LV function. A total of 476 hypertensive patients were prospectively recruited. All subjects underwent echocardiography and carotid ultrasound. LV geometry is categorized into four groups according to relative wall thickness (RWT) and LV mass index (LVMI). Concentric LV geometry was associated with increased carotid intima-media thickness (IMT), β-stiffness, and lower strain. All of the carotid parameters showed a stepwise change according to RWT of LV, whereas LV function was worse in hypertrophic geometry, as reflected by significantly lower systolic mitral annular velocity, higher left atrial volume index and E/E' ratio (P<0.001). By multivariate analysis after adjustment for clinical and laboratory parameters, IMT was independently associated with RWT, whereas myocardial function was independently associated with LVMI. Carotid arterial function and IMT showed worse values in concentric geometry, whereas LV systolic and diastolic function were worse in hypertrophic geometry, suggesting a discrepancy between carotid arterial and LV function in hypertensive patients.

Impact of age on left ventricular hypertrophy regression during antihypertensive treatment with losartan or atenolol (the LIFE study)

To assess the influence of age on changes in left ventricular (LV) mass and geometry during antihypertensive treatment, we related age to clinical and echocardiographic findings before and after 4 years of antihypertensive treatment in a subset of 560 hypertensive patients without known concurrent disease in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study, which randomized patients to blinded losartan- or atenolol-based treatment. Patients >/=65 years (older group) included more women and patients with isolated systolic hypertension or albuminuria (all P<0.05). Compared to patients <65 years, older patients had higher pulse pressure, LV mass, and prevalence of concentric hypertrophy at baseline (78 vs 69 mmHg, 234 vs 224 g, and 28 vs 16%, respectively, all P<0.01), while the mean blood pressure did not differ. Over 4 years, reductions in LV mass and the mean blood pressure were similar in both groups, but older patients more often had residual hypertrophy (31 vs 15%, P<0.001) with a preponderance of eccentric geometry. In multivariate analysis of 4-year change in LV mass controlling for baseline mass, larger hypertrophy reduction was associated with losartan treatment, while age, gender, body mass index, and 4-year change in pulse pressure and albuminuria did not enter (Multiple R (2)=0.40, P<0.001). Thus, in up-to-80-year-old hypertensive patients with left ventricular hypertrophy, age did not significantly attenuate hypertrophy reduction during antihypertensive treatment, although residual hypertrophy was more prevalent in older patients as a consequence of higher initial LV mass.

Influence of left ventricular geometry on regional systolic and diastolic function in patients with essential hypertension

OBJECTIVE

In essential hypertension, especially in concentric hypertrophy, global diastolic function is impaired. But, whether the left ventricular (LV) geometric pattern influences regional systolic and diastolic function or not, is unknown. This study was aimed to evaluate the influence of left ventricular geometric pattern on regional systolic and diastolic function in hypertensive patients.

DESIGN

Ninety untreated mild to moderate hypertensive patients were studied. M-mode parameters, standard Doppler and PW tissue Doppler indices were measured. Patients were divided into four groups according to left ventricular mass index and relative wall thickness: normal geometry (n = 16), concentric remodeling (n = 16), eccentric hypertrophy (n = 32) and concentric hypertrophy (n = 26).

RESULTS

Age, gender, body mass index, systolic and diastolic blood pressure were similar among groups. E/A ratio was significantly lower in the concentric hypertrophy group compared with the normal geometry group. Em velocity and Em/Am ratio in basal septum and Em velocity in basal inferior were statistically lower in the concentric hypertrophy group compared with the normal geometry group. In the concentric hypertrophy group, the number of segments with diastolic dysfunction was significantly higher compared with the normal geometry group. LV ejection fraction and regional S velocity could be compared among groups.

CONCLUSION

LV regional diastolic function is being impaired in concentric hypertrophy. LV regional systolic function does not show a difference according to the LV geometric pattern.

Early signs of cardiac involvement in hypertension

BACKGROUND

Whether abnormalities of diastolic function are the earliest cardiac change in hypertension is still a matter for dispute. The aim of this study was to assess whether left ventricular diastolic dysfunction is an early sign of cardiac involvement in hypertension.

METHODS

In 578 young patients with stage I hypertension from the Hypertension and Ambulatory Recording Venetia Study (HARVEST) and 101 normotensive control patients echocardiographic Doppler examination and ambulatory blood pressure monitoring were performed.

RESULTS

Left ventricular mass, wall thickness, and relative wall thickness, adjusted for confounders, were greater in the hypertensive than in the normotensive patients (all P <.0001). After adjustment for confounders, the A-wave peak velocity was higher in the hypertensive patients (51.5 +/- 11.5 vs 43.4 +/- 8 cm/s, P <.001) as were A-wave velocity time integral (5.6 +/- 1.7 vs 4.6 +/- 1.3 cm, P =.01), total area (16.9 +/- 4.4 vs 15.6 +/- 3.1 cm, P =.04), and E-wave peak velocity (69.9 +/- 15.2 vs 67.5 +/- 13.3 cm/s, P =.03). All indexes of diastolic function were similar in the hypertensive subjects subdivided according to whether they had "white-coat" or sustained hypertension. Among the hypertensive subjects, age and heart rate were the strongest predictors of diastolic indexes, whereas ambulatory blood pressure explained only a marginal part of the E/A ratio, A-wave peak velocity, and the first one third total area ratio (P =.04, P =.02, and P =.05, respectively). Left ventricular mass and wall thickness were not associated with any Doppler index. When a clustering of diastolic indexes (E/A wave ratio, deceleration time, first one third of diastole, and peak E-wave-velocity) was used to identify subjects with diastolic dysfunction, no significant differences in either clinic or ambulatory blood pressure were observed between the group with diastolic dysfunction and the group with normal function.

CONCLUSIONS

We conclude that the earliest signs of cardiac involvement in hypertension are left ventricular structural abnormalities. Left ventricular diastolic function is only marginally affected, even when multiple parameters of left ventricular filling are taken into account.

Left ventricular function, cardiac dysrhythmias, atrial activation, and volumes in nondipper hypertensive individuals with left ventricular hypertrophy

BACKGROUND

Arrhythmic patterns and left ventricular geometric adaptations to pressure overload were investigated in 76 patients with untreated borderline-to-moderate sustained essential hypertension studied by 2-dimensional and M-mode echocardiography, 12-lead, Holter, and signal-averaged electrocardiography, and ambulatory blood pressure monitoring.

METHODS AND RESULTS

Sixty-two age- and sex-matched normal adults were chosen for data comparison. Hypertrophic hypertensive patients were subdivided into 2 subgroups: 44 patients with nocturnal blood pressure reduction (dippers) and 32 patients without it (nondippers). Common afterload and diastolic function indexes were found to be lower in combined nondipper and dipper groups, but only fractional shortening decreased in nondippers. The number of premature atrial and ventricular contractions per hour was high in dippers and nondippers, with no statistically significant differences between them; atrial and ventricular complex dysrhythmias were similar. Signal-averaged electrocardiography showed a prolonged P-wave duration in dipper and nondipper patients with high atrial volumes but no late ventricular potentials and no difference in quantitative P-wave analysis. Left atrial volumes, P-wave duration, and premature atrial contractions were found to be positively linked to left ventricular hypertrophy. In nondipper patients a linear correlation was observed between left atrial volume and P-wave duration, although supraventricular ectopic activity was connected to left atrial volume enlargement both in dipper and nondipper patients.

CONCLUSIONS

These data suggest that the nondipper pattern is not linked to a worse arrhythmogenic substrate; only atrial volume increase may be related to significant supraventricular activity and prolonged atrial activation in nondipper patients, but late ventricular potentials are uncommon in hypertrophic hypertensive patients.

Factors of Importance to Doppler Indexes of Left Ventricular Filling in 50-Year-Old Hypertensive Persons

Altered left ventricular (LV) diastolic filling has been shown in subjects with hypertension. Age is a major determinant of Doppler indexes of LV diastolic filling; therefore, a group of subjects of uniform age should preferably be chosen, if other determinants of diastolic LV filling are to be studied. A limited body of data is available regarding Doppler indexes of LV filling in hypertensive persons of a similar age. We therefore evaluated 26 hypertensive subjects (13 women and 13 men) 50 years old by Doppler echocardiography. The peak velocity of early diastolic filling (E wave), the peak velocity of atrial filling (A wave), the early-to-atrial peak velocity (E/A) ratio, and the deceleration time of early velocity were measured. The peak E wave velocity was 0.76 +/- 0.11 versus 0.62 +/- 0.13 m/s (P < 0.005), and the E/A ratio was 1.11 +/- 0.24 versus 0.93 +/- 0.23 (P < 0.05) in hypertensive women and men, respectively. The peak A wave velocity was increased and the E/A ratio was decreased in both hypertensive women and men compared with healthy 50-year-old subjects. In multivariate analyses, LV diameter, body mass index, and gender correlated with the E/A ratio in hypertensive persons. It is concluded that there is a significant difference in Doppler LV filling indexes between 50-year-old hypertensive women and men. LV diameter, gender, and body mass index are independent determinants of LV diastolic inflow in similarly aged hypertensive persons.

Diastolic dysfunction and baroreflex sensitivity in hypertension

The determinants of diastolic dysfunction in patients with systemic hypertension are not completely known. To evaluate the possible role of age, arterial blood pressure, and baroreflex heart rate response impairment in causing diastolic dysfunction, we studied 61 patients (42 male; mean+/-SD age, 43.9+/-12 years) with newly recognized and therefore previously untreated systemic hypertension. Diastolic dysfunction was evaluated by means of Doppler echocardiography (and diagnosed as such when the early to atrial peak velocity ratio corrected to heart rate was <1), arterial blood pressure by 24-hour ambulatory monitoring, and baroreflex heart rate response by means of the spectral technique (alpha index) during paced (0.27 Hz) and spontaneous breathing (in a supine position and during tilt). Nineteen patients had diastolic dysfunction, the most powerful predictor of which was age (r=-0.63, P<0.001). The patients with diastolic dysfunction had significantly lower values for spectral baroreflex gain in the high-frequency band than those without (5.2+/-3 versus 8.4+/-5 ms/mm Hg during paced breathing, P<0.05; 7. 4+/-4 versus 13.3+/-7 ms/mm Hg in a supine position, P<0.05; 4.3+/-4 versus 5+/-2 ms/mm Hg during tilt, P<NS). Ambulatory blood pressure values were not significantly different in the patients with (137+/-14 and 89+/-9 mm Hg) and without (144+/-11 and 82+/-24 mm Hg) diastolic dysfunction. In conclusion, age and impaired baroreflex heart rate response (but not pressure overload) are determinants of left ventricular diastolic dysfunction in patients with newly recognized and untreated systemic hypertension.