Doppler tissue imaging

This paper try to give a general overview of the main areas of DTI clinical application, its main technical limitations, new directions still under investigation and some potential future developments of this emerging imaging technique. In this review article we pretend to discuss the main aspects of the new DTI method, its present "state of the art" and future perspectives of scientific and technical development.

Importance of lipoprotein metabolism parameters in the clinical and angiographic severity of coronary artery disease

Coronary artery disease that is clinically and angiographically significant is associated to important biochemical parameters with direct interference in lipoprotein and apoprotein metabolism. The purpose of our study was to evaluate the importance of several lipoprotein metabolic parameters in the clinical and angiographic severity of chronic coronary artery disease. In a population with the diagnosis of ischemic coronary artery disease, we assessed the degree of angiographic (single- versus multivessel disease) and clinical (C.C.S. I-IV classification) severities. In each patient, we determined the value of total cholesterol, triglycerides, HDL and LDL cholesterol, HDL 2 and 3, apoprotein AI and B, lipoprotein (a), anti-phospholipid antibodies and C reactive protein. Our results showed that some parameters were significant in the comparison between a normal group and the global coronary artery disease population, such as the value of total cholesterol, HDL cholesterol, HDL 2, apoprotein AI and B lipoprotein (a) and anti-phospholipid antibodies. In the distinction of coronary artery disease subgroups, in relation to C.C.S. < or = 2 and > or = 3 classes, some factors could be discriminated, such as HDL cholesterol, HDL 2, total cholesterol/HDL, lipoprotein (a), anti-phospholipid antibodies and C reactive protein. In the distinction between classes C.C.S. < or = 2 and AMI, the levels of triglycerides, HDL cholesterol, HDL 2, total cholesterol/HDL, lipoprotein (a) and anti-phospholipid antibodies were significant. In the division between single vessel versus multivessel coronary artery disease we found significant values of HDL cholesterol, HDL 2, total cholesterol/HDL, apoprotein AI, lipoprotein (a), anti-phospholipid antibodies and C reactive protein. In conclusion, our present study endorses the clinical role of lipids and plasma lipoproteins in the determination of several cardiovascular risk factors, but introduction of new parameters such as lipoprotein (a) and the anti-phospholipid antibodies can be very useful for a better and global understanding of the pathophysiological processes and distinction of higher risk subgroups for extension and degree of severity of ischemic coronary artery disease.

Myocardial architecture, texture and left ventricular heterogeneity in the pulsed Doppler tissue imaging pattern

The regional contribution for the global ventricular functional performance is complex and heterogeneous, the myocardial texture could reflect this particular aspect, during the phases of myocardial contraction and relaxation. The objective of our clinical study was to evaluate the relationship between the segmental myocardial velocity pattern by Doppler tissue imaging and the ultrasound characteristics of the left ventricular myocardium analysed by computerized ultrasound densitometry with the calculation of its intensity (dB), in a population of 22 subjects without clinical history of cardiovascular pathology, 50% female gender, mean age 43 +/- 11 years (19-66 years). In the methodology of study, the left ventricular myocardium was divided in 16 segments, according with the transthoracic echocardiographic recommendations of the American Society of Echocardiography (A.S.E.). During one cardiac cycle interval, the ultrasound characteristics of the left ventricular myocardium were evaluated continuously and in a quantitative manner, applying the computerized ultrasound densitometry method on the gray scale images of the ventricular myocardium, with the sample size identical to the myocardial wall thickness. The peak (Vmax-cm/sec) and mean (Vm-cm/sec) pulsed Doppler tissue imaging velocities, individuals, segmental and a total velocities, contraction and relaxation velocities of the left ventricular myocardium were obtained immediately after the computerized ultrasound densitometry analysis. Ultrasound densitometry and Doppler tissue imaging data were obtained in a total number of 352 left ventricular myocardial segments. Using the multiple linear correlation matrix analysis, the ultrasound intensity registered inverse significant correlation's with the Doppler tissue imaging Vmax and Vm for the systolic "s" wave in the total segments and each one of them (r = -0.66; p = 0.001; interval 2-18 cm/sec; r = -0.52 to -0.70) and with the early diastolic "e" wave (r = -0.42; p = 0.01; interval 2-19 cm/sec; r = -0.35 to -0.55). Direct correlation's were obtained for the computerized ultrasound densitometry intensity and Doppler tissue imaging Vmax and Vm of the late diastolic "a" wave in the total number of the left ventricular myocardial wall segments and in each one of them (r = 0.51; p = 0.01; interval 1-17 cm/sec; r = 0.42 a 0.66). We conclude that in our study and under physiological conditions of myocardial performance, a direct correlation was obtained between the ultrasound characteristics of the ventricular myocardial imaging and its velocities of contraction and relaxation. These facts reflect the close relationship between left ventricular myocardial structure and function, analyzed by the new ultrasound Doppler technologies.

[The acquired immunodeficiency syndrome, hypertrophic myocardiopathy and multivalvular infectious endocarditis. Apropos a clinical case]

We present a clinical case of a 33 years old young male, gypsy, intravenous drug abuser with heroine and cocaine and AIDS diagnosis. The clinical anamnesis was mainly fever and systolic heart murmur in a clinical scenario of AIDS. The two-dimensional echocardiographic study was clearly diagnostic of an hypertrophic obstructive cardiomyopathy of the left ventricle. This study showed also the presence of multiple vegetations of the mitral, aortic and pulmonic valves in a clinical setting of an acute Streptococcus Viridans infective endocarditis. In this case report we discuss the incidence of this type of multiple cardiac lesions and particularly the presence of this specific pathogenic agent in this high risk group of patients with intravenous drug abuse and systemic immunosuppression. We pointed out the rarity of these findings of left side valvular vegetations associated with this type of cardiomyopathy and the different factors related to infective endocarditis.

[A pulsed Doppler study of left atrial and ventricular inflow in 2 populations of normotensive and hypertensive subjects]

OBJECTIVE

Comparative analysis of left atrial and left ventricle Doppler inflow patterns in patients with essential systemic mild to moderate hypertension and normal global left ventricular systolic function.

PATIENTS

A group of out patients with the diagnosis of hypertension referred to the Echocardiographic Laboratory of Egas Moniz Hospital in Lisbon.

SETTING

Echocardiographic Doppler prospective study.

MATERIAL AND METHODS

We studied a group of 50 patients with the diagnosis of mild to moderate arterial hypertension (Group H), which was compared with a population of 50 normal subjects (Group N). In each case we analysed the pulsed Doppler flow of the right upper pulmonary vein and the diastolic inflow of the left ventricular cavity. We calculated the peak velocities and time velocity integrals of the systolic, diastolic and atrial contraction waves of the pulmonary venous flow and also the systo-diastolic velocity and time velocity integral ratios. In the transmitral Doppler flow analysis we evaluated the peak velocities and time velocity integrals of the early (E wave) and late (A wave) waves, and their time velocity and velocity ratio. We assessed also the isovolumic relaxation time and left ventricular mass index.

RESULTS

In groups N and H the peak velocity of the pulmonary venous flow systolic wave was 0.53 +/- 0.15 cm/sec and 0.75 +/- 0.10 cm/sec (p = 0.01), diastolic wave was 0.50 +/- 0.10 cm/sec and 0.41 +/- 0.09 cm/sec (p = 0.03) and atrial contraction wave was 0.18 +/- 0.03 cm/sec and 0.35 +/- 0.08 (p = 0.001), with a systo-diastolic ratio of 1.06 +/- 0.10 and 1.83 +/- 0.10 (p < 0.001), respectively. In these two groups the time velocity integral of the pulmonary venous flow systolic wave was 14.4 +/- 2.6 cm and 17.8 +/- 1.8 cm (p = 0.001), the diastolic wave was 12.5 +/- 3.2 cm and 9.3 +/- 1.3 cm (p = 0.05) and the atrial contraction wave was 4.4 +/- 0.07 cm (p = 0.001), with a systo-diastolic ratio of 1.1 +/- 0.16 and 1.9 +/- 0.12 (p < 0.001), respectively. For the group H and considering the three subgroups, hypertensive patients without anatomical or functional alterations, with isolated diastolic dysfunction and with left ventricular hypertrophy associated to diastolic dysfunction, the velocity systo-diastolic ratio was 1.08 +/- 0.12, 1.57 +/- 0.08 (p < 0.01) and 2.4 +/- 0.08 (p < 0.01) and 2.4 +/- 0.08 (p < 0.001), the systo-diastolic time velocity integral ratio was 1.22 +/- 0.17, 1.72 +/- 0.13 (p < 0.01) and 2.4 +/- 0.15 (p < 0.001), the peak velocity of the atrial contraction wave was 0.28 +/- 0.07, 0.3 +/- 0.08 (p < 0.01) and 0.43 +/- 0.07 (p < 0.001) and its time velocity integral was 4.6 +/- 0.06 cm, 5.6 +/- 0.07 cm (p < 0.01) and 7.0 +/- 0.08 cm (p < 0.001).

CONCLUSIONS

Pulsed Doppler study of pulmonary venous flow is significantly abnormal in patients with arterial hypertension. This abnormal pulmonary venous flow pattern has a close relationship with structural and functional alterations of the left ventricle. Combined analysis of the pulsed Doppler inflow at these two cardiac anatomical levels is fundamental to understand the pathophysiology of hypertensive heart disease.

[A double ambulatory product (blood pressure and heart rate), mild arterial hypertension and left ventricular hypertrophy]

OBJECTIVE

Analysis of the different ambulatory blood pressure monitoring derived parameters in terms of cardiac structural repercussion, in patients with isolated systolic and mild systolic-diastolic hypertension.

SETTING

Prospective study involving simultaneously the two-dimensional echocardiographic technique and the ambulatory blood pressure monitoring method.

PATIENTS

Out patients regularly observed in the Cardiology Department of Egas Moniz Hospital in Lisbon, were included in our study.

MATERIAL AND METHODS

We studied 50 hypertensive patients who fulfilled the inclusion criteria of our study (Group H) and 20 subjects who were the normal aged matched population (Group N). through ambulatory blood pressure monitoring, in each individual of these two groups, we considered the mean values of daily systolic blood and diastolic blood pressure, heart rate and ambulatory heart rate blood pressure product. Through two-dimensional echocardiography we calculated the left ventricular mass and the correspondent index corrected for the body surface.

RESULTS

In the H group an comparing to the N group, the mean value of the daily systolic blood pressure was 112 +/- 6 mmHg and 159 +/- 8 mmHg (p < 0.001) respectively, diastolic blood pressure was 60 +/- 5 mmHg and 75 +/- 7 mmHg respectively (p < 0.001), heart rate blood pressure product was 6720 +/- 580 and 12561 +/- 678 (p < 0.0001) and of the left ventricular mass index was 109 +/- 10 gm2 and 145 +/- 7 g/m2 (p < 0.001). The correlation coefficient between the left ventricular mass index and mean systolic, diastolic blood pressures and ambulatory heart rate blood pressure product was 0.60 (p < 0.01), 0.45 (p = NS) and 0.73 (p < 0.001) respectively.

CONCLUSIONS

In the evaluation of the increase in left ventricular mass, ambulatory heart rate blood pressure product is a more accurate parameter compared to the mean daily blood pressure values. Ambulatory blood pressure monitoring is a method with a great potential and clinical application, when studying patients with hypertension diagnosis.

[The indices of pressure variability by noninvasive ambulatory monitoring of the arterial pressure. A study in 2 normotensive and hypertensive populations]

OBJECTIVE

Analysis of different indices of blood pressure (BP) variability using the ambulatory blood pressure monitoring (ABPM) method in two populations of hypertensive patients (HTA Group) and normotensive volunteers (NOR Group).

SETTING

Noninvasive prospective ambulatory study to assess the alterations of the circadian blood pressure profile through ABPM indices of blood pressure variability.

PATIENTS

Patients with the diagnosis of essential arterial hypertension referred for clinical investigation to the Cardiology Department of Egas Moniz Hospital in Lisbon.

MATERIAL AND METHODS

40 hypertensive patients (HTA Group) and 30 normal subjects (NOR Group) were included in this study. We calculated the short and long term variability indices. The short term variability indices were the casual and mean immediate BP deviation, percentage of BP peaks and BP peak relative deviation and maximal range variation. Some clinical and general factors considered were namely age, gender, height, weight, body area and index, mean and casual systolic-diastolic blood pressure.

RESULTS

Concerning systolic blood pressure in hypertension Vs normal groups respectively, the casual BP deviation was 15 +/- 4 mmHg and 7 +/- 4 mmHg (p 0.003), the mean immediate BP deviation was 18.5 +/- 4 mmHg and 7.5 +/- 3 mmHg (p 0.002), the percentage of BP peaks was 27 +/- 6% (p < 0.001), the percentage of BP peak area was 29 +/- 7% and 6 +/- 3% (p 0.001) and the percentage of relative deviation was 14 +/- 4% and 8 +/- 3% (p 0.03). For diastolic blood pressure all differences were not statistically significant between the two groups and the same happened for systolic blood pressure in relation to standard deviation and maximal range variation. Among these parameters and general and clinical characteristics, the systolic mean and casual blood pressure level showed an acceptable correlation with mean immediate deviation (R = 0.54/0.49), percentage of BP peaks (R = 0.56/0.49) and percentage of BP peak area (R = 0.60/0.53).

CONCLUSIONS

Blood pressure variability can be adequately evaluated through the method of ambulatory blood pressure monitoring. Some variability indices can be extracted from the 24 hour curves of ambulatory blood pressure monitoring. Long-term variability indices are not related to the level of blood pressure. In the hypertension group we found a greater variability concerning short term indices, namely immediate deviation, percentage and are of peak curve.

[Assessment of the anti-hypertensive effect of diltiazem in delayed-action capsules by ambulatory monitoring of arterial pressure]

The aim of this parallel controlled-placebo study was to assess the antihypertensive effect of diltiazem in a slow release formulation in monotherapy by the ambulatory blood pressure monitoring (ABPM). Twenty patients with moderate essential hypertension entered the trial. Whole day ambulatory blood pressure (BP) monitoring, with a COLIN ABPM 630, was done after a wash-out period, after placebo administration and 60 days of therapy with diltiazem in a 120 or 180 mg once or twice daily administration. We verified by ABPM that placebo administration did not have an antihypertensive effect (146 +/- 10 mmHg/87 +/- 7 mmHg at base line to 145 +/- 8 mmHg/84 +/- 6 mmHg with placebo p = ns). Eithy four percent of the patients showed a significant systolic and diastolic BP decrease after 60 days of therapy (from 146 +/- 10 mmHg/87 +/- 7 mmHg at base line to 132 +/- 7/77 +/- 6 mmHg - p less than 0.025). In 56% of the patients this was achieved with 180 mg/day and this effect was sustained throughout the 24 hours. We did not find a significant decrease on heart rate. The ABPM is a valuable technique to assess the effect of antihypertensive drugs and demonstrated that diltiazem in a slow release formulation was effective in decreasing systolic and diastolic BP, throughout the day even in patients with low doses, once daily.

[Significance of the unexpected hypertensive response to exertion. Correlation with ambulatory blood pressure monitoring and echocardiography]

The aim of this study was to analyse the meaning of unexpected hypertensive response during treadmill stress test in resting normotensive individuals without any evidence of cardiovascular pathology. The study group of 52 persons who fulfil the inclusion criteria was compared with a homogenous control population composed by 200 individuals with a suitable blood pressure response to stress. The adopted criteria for hypertensive response were the presence of blood pressure greater than or equal to 180/100 mmHg after 6 stress, in maximal stress greater than or equal to 210/110 mmHg and after 5' recovering greater than or equal to 150/90 mmHg. 74% of patients with hypertensive response appeared to be hypertensive according to the criteria of ambulatory blood pressure monitoring--day blood pressure greater than or equal to 140/90 mmHg and night blood pressure greater than or equal to 120/80 mmHg. After echocardiographic study to define the index of left ventricular mass, 68% of individuals with hypertensive stress response showed left ventricular hypertrophy with a medium index of 145 + 17 g/m2 (P less than or equal to 0.01) in most cases with a concentrical hypertrophy type. The appearance of tensional response of hypertensive type ascertains the probability of hypertensive disease. The analysis of tensional response to stress is an integrant part of a methodology of approaching patients suspect of high blood pressure.