Left-Ventricular Diastolic Function and Hypertension

Comparison of the Effects of Nitroglycerin and Nitroprusside on Transmitral Doppler Flow Parameters in Patients with Hypertensive Urgency

BACKGROUND:

Sodium nitroprusside (NIP) and nitroglycerin (NIT) are frequently selected agents for acutely reducing blood pressure. However, it is not clear which agent is more efficacious in improving left ventricular filling pressure in hypertensive crises.

OBJECTIVE:

To compare the acute effects of nitroglycerin (NIT) and nitroprusside (NIP) on transmitral Doppler filling parameters in patients with hypertensive urgency.

METHODS:

We identified 37 patients from our emergency department with hypertensive urgency and left ventricular filling abnormalities. Hypertensive urgency was defined as a severe blood pressure elevation without evidence of progressive end-organ injury. Patients were randomized to receive an infusion of NIT or NIP. NIT was infused at a starting dose of 10 μg/min; NIP was infused at a starting dose of 0.25 μg/kg/min. The infusion rates were adjusted to decrease mean arterial pressure by 25%, and this reduction was obtained within 2 hours in all patients. Diastolic filling parameters were measured by using echocardiography before and after treatment. Pulsed-wave Doppler transmitral flow velocities were used. Early diastolic flow, atrial contraction signal, early diastolic flow/atrial contraction signal, deceleration time, and isovolumetric relaxation time (IVRT) were measured.

RESULTS:

There were no differences between groups in baseline demographic and echocardiographic parameters. Blood pressure decreased significantly in both treatment groups. In posttreatment echocardiographic examinations, atrial contraction signal, deceleration time, and IVRT were significantly decreased in both treatment groups. Early diastolic flow was significantly decreased in the NIT group. There were no significant differences between the groups in terms of posttreatment early diastolic flow, atrial contraction signal, deceleration time, and IVRT values.

CONCLUSIONS:

In hypertensive urgency with left ventricular filling abnormalities, reduction of blood pressure associated with NIT or NIP treatment may improve transmitral Doppler filling parameters. There were no differences demonstrated between the 2 agents.

Comparison of the echocardiographic and pulmonary function test findings in orderly treated and untreated essential hypertensive patients

OBJECTIVE

Although it has been well established that hypertension effects pulmonary functions negatively, the effect of regular antihypertensive therapy on pulmonary functions is not known. In this study, we aimed to compare the pulmonary function tests of the hypertensive patients taking regular antihypertensive therapy with those of the ones not taking any antihypertensive medicine, to document the differences in pulmonary functions of both hypertensive groups.

MATERIALS AND METHODS

Patients who had received antihypertensive treatment (Group I: 29 males, 24 females, mean age 42.3 +/- 8.2 years), and untreated cases (Group II: 28 males, 22 females, mean age 43.4 +/- 6.4 years) were included in the study. Patients with a history of coronary heart disease, respiratory diseases, smokers and those who were obese were excluded from the study.

RESULTS

Forced vital capacity (FVC) and forced expiratory volume at the first second (FEV1) levels were found significantly lower in Group II (p < 0.05). In echocardiographic evaluation, the mitral E/A ratio of Group II was lower than that of Group I (p < 0.05). Isovolumetric relaxation time and deceleration time was higher in Group II than in Group I (p < 0.05). There was a significant association between pulmonary function tests and impaired left ventricular diastolic parameters; especially, mitral E/A ratio was significantly associated with decreased FVC and FEV1 in Group II (respectively r = -0.695, p = 0.01 and r = -0.591, p = 0.03).

CONCLUSION

FVC and FEV1 levels in untreated hypertensive cases were lower than in those of treated hypertensive cases, and this may be caused by diastolic function rather than the systolic function. In the evaluation of dyspnea in hypertensive patients, it would be useful to examine respiratory function in addition to echocardiographic investigation.

Physiology of diastolic function and transmitral pressure-flow relations

The study of diastolic function, in particular, the creative application of noninvasive modalities, such as echocardiography and MR imaging, requires an understanding and appreciation of the basic physiology of left ventricular filling dynamics. The physics and physiology of diastolic function and dysfunction is examined by relating the phasic patterns of transmitral flow to the properties of the cardiac chambers. Particular attention is paid to the equations governing the transmitral pressure-flow relations and the active and passive chamber properties that determine the flow patterns: Active relaxation, passive compliance, viscoelasticity, and elastic deformation. The physiologic role of diastolic suction is discussed within this context.

Increased left ventricular mass index and nocturnal systolic blood pressure in patients with Type 2 diabetes mellitus and microalbuminuria

AIMS

To compare left ventricular mass (LVM) index and function in patients with Type 2 diabetes mellitus with and without microalbuminuria and to investigate the clinical determinants of left ventricular hypertrophy.

METHODS

Echocardiography, electrocardiography and 24-h ambulatory blood pressure monitoring were performed in microalbuminuric (n = 29) and normoalbuminuric (n = 29) patients with Type 2 diabetes and no clinical evidence of heart disease. Groups were individually matched for age, sex and diabetes duration and smoking status.

RESULTS

LVM index (62 (34-87) vs. 52 (33-89) g/m2.7, P = 0.04) and LVH prevalence, using two out of three definitions, were greater in patients with microalbuminuria (LVM/height2.7: 72 vs. 59%, P = 0.27, LVM/height: 66 vs. 38%, P = 0.04, LVM/body surface area: 59 vs. 31%, P = 0.03). Night-time systolic blood pressure (126 (99-163) vs. 120 (104-157) mmHg, P = 0.005) and the night/day systolic blood pressure ratio (0.92 (0.08) vs. 0.88 (0.06), P = 0.04) were higher in those with microalbuminuria. Systolic and diastolic function were similar in both groups. Linear regression analyses showed that body mass index (BMI) was significantly related to loge LVM index (R2 = 11.8%, P = 0.005) and a relationship with night/day systolic blood pressure was also suggested (R2 = 4.6%, P = 0.057).

CONCLUSIONS

In patients with Type 2 diabetes, LVH is more common and severe in those with microalbuminuria. Its presence may be related to raised night/day systolic blood pressure ratio and is significantly related to BMI. The high prevalence of LVH strengthens the case for echocardiographic screening in Type 2 diabetes to identify high risk patients who might benefit from aggressive cardiovascular risk factor intervention.

Left ventricular diastolic dysfunction in patients with hypertension and preserved systolic function

OBJECTIVE

To assess prospectively diastolic function in hypertensive patients with preserved left ventricular function, particularly focusing on the limitation of the transmitral flow velocity curve alone to detect diastolic dysfunction.

PATIENTS AND METHODS

Comprehensive Doppler analysis was performed in 51 hypertensive patients with preserved left ventricular systolic function.

RESULTS

The ratio of the peak early diastolic filling wave velocity to the peak velocity of filling wave at atrial contraction was less than the age-adjusted mean value minus 2 SD in 16 patients, and the other 35 patients had a "normal" transmitral Doppler signal. However, the combined transmitral and pulmonary venous Doppler analysis revealed that 12 of these 35 patients had a "pseudonormal" pattern. The prevalence of diastolic dysfunction was estimated at 31% with use of transmitral Doppler alone but increased to 55% when comprehensive Doppler analysis was used (P < .05).

CONCLUSION

The presence of diastolic dysfunction has been frequently overlooked in hypertensive patients with transmitral Doppler analysis alone, and an assessment of diastolic function with a comprehensive Doppler analysis is needed in patients at risk for diastolic dysfunction.