OUP user menu

Tissue Doppler echocardiography in persons with hypertension, diabetes, or ischaemic heart disease: the Copenhagen City Heart Study

Rasmus Mogelvang , Peter Sogaard , Sune A. Pedersen , Niels T. Olsen , Peter Schnohr , Jan S. Jensen
DOI: http://dx.doi.org/10.1093/eurheartj/ehn596 731-739 First published online: 28 January 2009

Abstract

Aims To test the hypothesis that echocardiographic tissue Doppler imaging (TDI) reveals reduced myocardial function in hypertension, diabetes, and ischaemic heart disease (IHD) in the general population.

Methods and results Within a large, community-based population study, cardiac function was evaluated in 1036 participants by both conventional echocardiography and colour TDI. Peak systolic (s′) and early diastolic (e′) velocities, longitudinal displacement (LD), and the ratio of mitral inflow E-wave to e′ (E/e′) were measured. TDI revealed significantly impaired parameters of systolic and diastolic cardiac function in hypertension [n = 345; LD 10.1 (±standard deviation, SD 2.0 mm), P < 0.001; E/e′ 12.4 (×÷SD 1.4), P < 0.001], diabetes [n = 65; LD 9.8 (±SD 2.2 mm), P < 0.001; E/e′ 12.7 (×÷SD 1.5), P < 0.001], and IHD [n = 93; LD 9.4 (±SD 2.5 mm), P < 0.001; E/e′ 13.0 (×÷SD 1.5), P < 0.001] compared with controls [n = 533; LD 11.4 (±SD 2.0 mm); E/e′ 9.0 (×÷SD 1.3)]. This pattern remained significant after adjusting for age, sex, body mass index, heart rate, and the results of conventional echocardiography.

Conclusion In the general population, persons with hypertension, diabetes, or IHD have impaired cardiac function by TDI independently of the result of conventional echocardiography.

Keywords
  • Echocardiography
  • Tissue Doppler imaging
  • Population
  • Ischaemic heart disease
  • Hypertension
  • Diabetes mellitus
See page 642 for the editorial comment on this article (doi:10.1093/eurheartj/ehp067)

Introduction

As populations age and treatment for ischaemic heart disease (IHD) is refined, heart failure is becoming increasingly common. Hence, hypertension and diabetes become obvious targets for prevention, being two of the key risk factors for IHD and heart failure.1,2 The burgeoning epidemic of these clinical entities emphasizes the need for rapid, cheap, and non-invasive diagnostic methods to identify high-risk subjects with early myocardial deterioration so as to ensure that preventive therapy be initiated.

Studies have indicated that the echocardiographic technique of tissue Doppler imaging (TDI) enables detection of impaired myocardial performance in patients with hypertension,3,4 diabetes,57 and IHD8,9 in the hospital setting. If TDI proves able to detect subclinical myocardial dysfunction in non-hospitalized persons in the community, its diagnostic usefulness would be consolidated and the integration of TDI into routine echocardiographic examination would be further motivated; particularly so if TDI provides information incremental to that of conventional echocardiography.

We therefore performed a large population-based study, evaluating the characterization of myocardial function by TDI in persons with hypertension, diabetes, or IHD compared with controls.

Methods

Study population

This study was performed as a substudy of the 4th Copenhagen City Heart Study, a longitudinal cohort study of cardiovascular disease and risk factors.10,11 At the first examination in 1976–78, a random sample of 19 329 predominantly Caucasian citizens living within a well-defined area of the inner Copenhagen City boundary was drawn from the Central Office of Civil Registration and invited to take part in the study. At the fourth examination in 2001–03, a total of 12 600 persons were invited in a random order. This study population consisted of persons whom had been invited to the previous examinations (n = 11 600), supplemented by a random sample of persons from the younger age strata (n =1000). Out of these, 6238 (49.5%) participated. The present paper includes 1036 men and women (20–93 years) who underwent an echocardiographic examination, including colour TDI. The participants were randomly selected and all consented to participate; thus whether or not a participant underwent echocardiography was completely independent of his or her health status and other risk factors. Persons with atrial fibrillation, significant valvular stenosis, or regurgitation were excluded.

All subjects gave informed consent to participate, and the study was performed in accordance with the second Helsinki Declaration and approved by the regional ethics committee.

Health examination

Hypertension was defined as systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg or use of antihypertensive medication.12 Diabetes mellitus was defined as plasma glucose concentration ≥11.1 mmol/L, use of insulin or other antidiabetic medicine, self-reported disease, or HbA1c level >7.0%.13,14 IHD was defined as either a history of hospital admission due to acute coronary artery occlusion, percutaneous coronary intervention, or coronary artery bypass grafting, or major ischaemic alterations on the electrocardiogram as defined by the Minnesota codes 1.1–3. Participants without hypertension, diabetes, and IHD were defined as controls.

Echocardiography

Three experienced echo technicians using GE Vingmed Ultrasound’s Vivid Five with a 2.5 MHz probe (Horten, Norway) performed all echocardiograms. All subjects were examined with colour TDI, two-dimensional and M-mode echocardiography in the left lateral decubitus position. All images were recorded using second harmonic imaging at the time of end-expiration. The collected data were stored on magneto-optical discs and an external FireWire hard drive (LaCie, France) and analysed off-line with the commercially available software (EchoPac, GE Medical, Horten, Norway), with the investigator being blinded to other information.

Conventional echocardiography

The 16 standard segments model, as suggested by the American Society of Echocardiography,15 was used for the evaluation of regional function. Evaluation of left ventricular ejection fraction was made by one observer based on the wall motion index score. Left ventricular systolic dysfunction was defined as left ventricular ejection fraction <50%.

One loop was recorded of the parasternal long axis and one M-mode still frame in correct 90° angle between the tips of the mitral leaflets and the tips of the papillary muscles. If the correct angle could not be obtained, two-dimensional images were used instead to quantify the myocardial thickness and the dimensions of the left ventricle. Left ventricular mass index was calculated as the anatomic mass16 divided by body surface area.17 Left ventricular hypertrophy was defined as left ventricular mass index ≥104 g/m2 for women and ≥116 g/m2 for men.18 Left ventricular dilatation was considered present if the diameter of the left ventricle at end diastole/height ≥3.3 cm/m.15

Pulsed-wave Doppler at the apical position was used to record mitral inflow between the tips of the mitral leaflets. Peak velocities of early (E) and atrial (A) diastolic filling and deceleration time (DT) of the E-wave were measured and the E/A ratio was calculated. Mild diastolic dysfunction was defined as E/A< 1 and DT > 240 ms. Severe diastolic dysfunction was defined as DT < 140 ms and E/A<50 years> 2.5, E/A50–70 years> 2, or E/A>70 years> 1.5, respectively.19

A normal conventional echocardiographic examination identified subjects without left ventricular hypertrophy, dilatation, ejection fraction <50%, and mild or severe diastolic dysfunction.

Colour tissue Doppler imaging

Colour TDI loops were obtained in the apical 4-chamber, 2-chamber, and apical long-axis views at the highest possible frame rate (median 133; interquartile range 37 frames per second). One observer performed the TDI analyses. Peak systolic (s′), early diastolic (e′), and late diastolic (a′) velocities were measured within a 6 mm circular sample volume as shown in Figure 1. Smoothing was set to 30 ms. Longitudinal displacement (LD) was calculated as the integral of the velocity curve during ejection. Left ventricular longitudinal function was assessed by averaging myocardial velocities and displacement in the septal, lateral, inferior, anterior, posterior, and anteroseptal mitral annular positions. Inter-observer variability of mitral annular velocities has been reported to be low.20

Figure 1

Example of myocardial velocity curve by colour tissue Doppler imaging. In this apical 4-chamber view (focus on left ventricle), the sample is obtained at the septal region of the mitral annulus (yellow circle). Y-axis represents myocardial velocity (cm/s) and the X-axis represents time. The velocity curve has a positive peak (s′) during systole and two negative peaks during diastole, an early (e′) and a late (a′) peak.

Statistical analysis

In Table 1, comparisons between groups were performed by Student’s t-test and Fisher’s exact test. Absolute values of diastolic tissue velocities were used in the statistical analyses and described as such in the text. The ratio (E/e′) of mitral inflow E-wave to peak early diastolic velocity (e′) was positively skewed and therefore logarithmically transformed prior to further analysis: the mean values presented in the text are geometric mean values, unless otherwise stated.

View this table:
Table 1

Population characteristics

Control (n = 533)Hypertension (n = 345)Diabetes (n = 65)IHD (n = 93)
Age, years51 (±14)69 (±11)68 (±11)69 (±12)
Male sex, %44 (233)36 (123)65 (42)§37 (34)
Body mass index, kg/m224.5 (±3.3)26.7 (±4.5)27.3 (±3.3)26.7 (±4.4)
Heart rate, b.p.m.67 (±10)71 (±11)73 (±11)69 (±11)
Diastolic dysfunction
 Mild, %2 (11)7 (24)15 (10)8 (7)
 Severe, %0.6 (3)0.9 (3)01.1 (1)
LVEF <50%, %0.4 (2)0.9 (3)06.5 (6)
LV dilatation, %3 (16)7 (23)#8 (5)18 (17)
LV hypertrophy, %7 (36)22 (75)34 (22)43 (40)
Peak systolic velocity (s′), cm/s6.4 (±1.2)5.6 (±1.2)5.8 (±1.4)5.2 (±1.2)
Peak early diastolic velocity (e′), cm/s8.4 (±2.5)5.7 (±1.9)5.6 (±2.1)5.5 (±2.0)
Peak late diastolic velocity (a′), cm/s6.3 (±1.9)7.2 (±1.8)7.5 (±2.1)6.0 (±2.1)
E/e9.0 (×÷1.3)12.4 (×÷1.4)12.7 (×÷1.5) 13.0 (×÷1.5)
Longitudinal displacement, mm11.4 (±2.0)10.1 (±2.0)9.8 (±2.2)9.4 (±2.5)
  • The four groups, control, hypertension, diabetes, and ischaemic heart disease (IHD), refer to: subjects without hypertension, diabetes, and IHD; subjects with hypertension but no diabetes nor IHD; subjects with diabetes but no IHD; and subjects with IHD, respectively. Standard deviations and numbers are cited in parentheses for continuous and categorical traits, respectively. The values for E/e′ represent geometric means, so they have to be multiplied/divided with the standard deviations. LV, left ventricular; EF, ejection fraction. P < 0.001 compared with the control group. P = 0.020 compared with the control group. §P = 0.002 compared with the control group. P = 0.010 compared with the control group. #P = 0.012 compared with the control group.

Associations to the TDI parameters were tested for the defined groups by univariate and multivariable regression analyses including pre-specified variables: age, sex, body mass index, and heart rate, and subsequently conventional echocardiography. These variables were chosen because they have been suggested in the literature to influence the TDI parameters. First-order interactions were tested among all variables, and the Bonferroni correction was used to exclude multiple significances. Multivariable adjustments were performed for each TDI parameter separately. Linearity, variance homogeneity, and the assumption of normality were tested with plots of residuals. Trends were analysed by linear regression analyses by considering the groups as a continuous variable, and departure from linearity was assessed by simultaneous assessment of linear and quadratic effects. P-values <5% on two-sided tests were considered significant.

All analyses were performed by SAS software (SAS System for Windows, release 8.02, SAS Institute Inc., Cary, NC, USA).

Results

Conventional echocardiography

Characteristics of the study population (n = 1036) after division into four groups (controls, hypertension, diabetes, and IHD) are displayed in Table 1. In the diabetes group, 80% had hypertension and in the IHD group, 73% had hypertension and 14% had diabetes. Participants with hypertension, diabetes, and/or IHD were characterized by higher age, higher body mass index, and a higher proportion of abnormal findings by conventional echocardiography in general, compared with controls. Whereas the proportion of mild diastolic dysfunction was higher in the hypertension and diabetes groups compared with the control group, there were no significant differences in the proportions of systolic and severe diastolic dysfunction assessed by conventional echocardiography. Systolic and mild diastolic dysfunction were more prevalent in the IHD group; severe diastolic dysfunction was not.

Tissue Doppler imaging

TDI revealed impaired systolic (s′ and LD) and diastolic performance (e′ and E/e′) in all three exposed groups (hypertension, diabetes, and IHD) compared with controls (Table 1 and Figure 2). Notably, these differences remained significant after adjustment for age, sex, body mass index, and heart rate:

Figure 2

Plots of cumulative percentages of parameters by tissue Doppler imaging of controls and exposed participants. Participants with hypertension, diabetes, and/or ischaemic heart disease constituted the exposed group (n = 503, green curves), whereas the control group (n = 533) consisted of participants without hypertension, diabetes, and ischaemic heart disease (blue curves). The black stippled line indicates the median. The X-axis represents untransformed parameters by tissue Doppler imaging.

hypertension group: s′ (P = 0.002), LD (P = 0.019), e′ (P < 0.001), and E/e′ (P < 0.001);

diabetes group: s′ (P = 0.042), LD (P = 0.007), e′ (P = 0.010), and E/e′ (P < 0.001);

IHD group: s′ (P < 0.001), LD (P = 0.017), e′ (P < 0.001), and E/e′ (P < 0.001).

Adjustment for age, sex, body mass index, and heart rate revealed a significantly lower mean value of a′ in the IHD group (P < 0.001) compared with the control, hypertension, and diabetes groups, whereas there was no significant difference between the latter groups regarding a′ (control vs. hypertension: P = 0.30; control vs. diabetes: P = 0.43).

Tissue Doppler imaging and conventional echocardiography

Figure 3 depicts TDI parameters of systolic and diastolic function for all four groups with abnormal and normal conventional echocardiography, respectively. In the subgroup of persons with normal conventional echocardiography, systolic and diastolic performance evaluated by TDI were still significantly reduced in the three exposed groups compared with controls (except from s′ in the diabetes group) (Figure 3). Estimated TDI parameters in the four groups after adjustment for age, sex, body mass index, heart rate, and result of the conventional echocardiography are listed in Table 2. After multivariable adjustment, systolic and diastolic performance by TDI were significantly reduced in the three exposed groups compared with controls, independently of the result of conventional echocardiography.

Figure 3

Parameters of systolic and diastolic function by tissue Doppler imaging according to the result of the conventional echocardiography. Control, HT, DM, and IHD refer to the control, hypertension, diabetes, and ischaemic heart disease groups, respectively. Abnormal conventional echocardiography designates the presence of left ventricular hypertrophy, dilatation, systolic, and/or diastolic dysfunction. Bars indicate standard errors. *P < 0.001, P = 0.008, and P = 0.08 compared with the control group.

View this table:
Table 2

Parameters derived by tissue Doppler imaging for hypertension, diabetes, and ischaemic heart disease compared with controls after multivariable adjusting

ControlHypertensionDiabetesIHD
Peak systolic velocity (s′), cm/sa5.45.15.14.8
−0.3 (−0.5 to −0.1)−0.3 (−0.6 to 0.1)−0.6 (−0.8 to −0.3)
P = 0.003P = 0.06P < 0.001
Peak systolic velocity (s′), cm/sb5.45.15.15.0
−0.3 (−0.5 to −0.1)−0.3 (−0.7 to 0.1)−0.4 (−0.7 to −0.1)
P = 0.012P = 0.12P = 0.031
Peak early diastolic velocity (e′), cm/sa6.55.95.95.9
−0.6 (−0.8 to −0.3)−0.5 (−1.0 to −0.1)−0.6 (−1.0 to −0.2)
P < 0.001P = 0.020P = 0.005
Peak early diastolic velocity (e′), cm/sb6.55.96.06.1
−0.6 (−0.8 to −0.3)−0.4 (−1.0 to 0.1)−0.3 (−0.8 to 0.2)
P < 0.001P = 0.15P = 0.21
Peak late diastolic velocity (a′), cm/sa6.36.26.25.3
−0.1 (−0.4 to 0.2)−0.1 (−0.6 to 0.3)−1.0 (−1.4 to −0.6)
P = 0.39P = 0.58P < 0.001
Peak late diastolic velocity (a′), cm/sb6.36.26.05.7
−0.1 (−0.4 to 0.2)−0.4 (−1.0 to 0.1)−0.6 (−1.0 to −0.1)
P = 0.40P = 0.13P = 0.035
E/ea11.212.412.812.6
× 1.11 (1.06–1.16)× 1.14 (1.06–1.23)× 1.12 (1.05–1.20)
P < 0.001P < 0.001P = 0.001
E/eb11.212.412.611.1
× 1.10 (1.05–1.15)× 1.11 (1.01–1.22)× 0.98 (0.90–1.07)
P < 0.001P = 0.024P = 0.63
Longitudinal displacement, mma10.510.19.99.7
−0.3 (−0.6 to −0.1)−0.6 (−1.1 to −0.1)−0.7 (−1.2 to −0.3)
P = 0.037P = 0.013P = 0.003
Longitudinal displacement, mmb10.510.210.010.1
−0.3 (−0.6 to 0.1)−0.4 (−1.1 to 0.2)−0.3 (−0.9 to 0.3)
P = 0.14P = 0.20P = 0.33
  • The example shows the estimated values for 70-year-old women with body mass index 25 kg/m2, heart rate 60 b.p.m., and normal conventional echocardiography in the control, hypertension, diabetes, and ischaemic heart disease (IHD) groups, respectively. The estimated differences between controls and the exposed groups are displayed beneath the estimated values. There were no significant interactions between conventional echocardiography and the groups for any of the TDI parameters. The four groups, control, hypertension, diabetes, and IHD, refer to: subjects without hypertension, diabetes, and IHD; subjects with hypertension but no diabetes nor IHD; subjects with diabetes but no IHD; and subjects with IHD, respectively. 95% confidence intervals are cited in parentheses. aRefers to adjustment for age, sex, body mass index, heart rate, and conventional echocardiography. bRefers to adjustment for age, sex, body mass index, heart rate, conventional echocardiography, and the insignificant interactions between conventional echocardiography and the groups.

Including the insignificant interactions between conventional echocardiography and the groups in the multivariable analyses revealed the same pattern, although not all of the TDI parameters reached statistical significance (Table 2).

Tissue Doppler imaging in persons with elevated blood pressure

In order to examine the effect of increasing blood pressure on TDI parameters of systolic and diastolic function, the study population was stratified into four groups regarding blood pressure: normal, pre-hypertension, hypertension stage 1, and hypertension stage 2.12 Figure 4 visualizes how myocardial function as assessed by TDI decreases according to increasing blood pressure groups. This effect persisted after adjustment for age, sex, body mass index, heart rate, diabetes, IHD, and conventional echocardiography, with systolic and diastolic function by TDI decreasing linearly with increasing blood pressure groups: LD (P = 0.019), and s′, e′, and E/e′ (P < 0.001).

Figure 4

Parameters of systolic and diastolic function by tissue Doppler imaging according to blood pressure classes. The study population was divided into four groups according to blood pressure: normal <120/80 mmHg, 120/80 mmHg ≤pre-hypertension <140/90 mmHg, 140/90 mmHg ≤ stage 1 hypertension <160/100 mmHg, and 160/100 mmHg ≤ stage 2 hypertension.11 HT, hypertension. Bars indicate standard errors.

When the analyses were confined to persons without hypertension, TDI parameters continued to be significantly lower in the pre-hypertension group compared with persons with normal blood pressure, although only the diastolic parameters were significantly impaired after multivariable adjustment: e′ (P < 0.001); E/e′ (P = 0.014).

Tissue Doppler imaging in persons without hypertension, diabetes, and ischaemic heart disease

Myocardial performance was significantly reduced in the exposed groups, despite multivariable adjustment. The TDI parameters were, however, associated with age, sex, body mass index, and heart rate also. Figure 5 exhibits the expected values of the TDI parameters according to age, sex, body mass index, and heart rate in persons without hypertension, diabetes, and IHD.

Figure 5

Expected tissue Doppler imaging parameters according to age and sex in persons without hypertension, diabetes, and ischaemic heart disease. Red and blue curves refer to women and men, respectively. Stippled curves indicate 95% confidence intervals. The values obtained by the plots should be corrected for body mass index and heart rate as follows: for every 1 kg/m2, body mass index is above 25 kg/m2; s′: −0.021 cm/s; e′: −0.063 cm/s; a′: 0.059 cm/s; and E/e′: ×1.009. For every beat per minute, the heart rate is above 60 b.p.m.: s′: 0.028 cm/s; a′: 0.069 cm/s; and LD: −0.023 mm.

Discussion

In the present population-based study of 1036 persons, we evaluated myocardial function by TDI comparing persons with hypertension, diabetes, and/or IHD to persons without. We found that TDI, in contrast to conventional echocardiography, revealed impaired systolic and diastolic function in all exposed groups compared with the control group. Furthermore, even after adjustment for the result of conventional echocardiography, TDI continued to show a reduced systolic and diastolic function in the groups with hypertension, diabetes, and IHD. Finally, we found a significant dose–response relationship between increasing blood pressure and impaired TDI parameters of myocardial performance.

Not surprisingly, the groups with hypertension, diabetes, and IHD had a higher mean age, body mass index, and higher frequency of abnormal findings by conventional echocardiography than controls (Table 1). The increased proportion of mild diastolic dysfunction in hypertension and diabetes groups was expected even in the general population.21 However, there was no significant difference in the proportion of systolic and severe diastolic dysfunction by conventional echocardiography when comparing participants with hypertension and/or diabetes (but not IHD) with controls. This may be due to the fact that, in order to affect these global measures, overall myocardial function must be impaired. Previous studies have shown that reduced longitudinal myocardial function is compensated by increasing radial contractility in diabetic22 and hypertensive4 patients. Although TDI parameters of longitudinal function were shown to be significantly impaired in these studies, there were no differences between controls and diabetic and hypertensive patients regarding left ventricular ejection fraction4,22 DT, or E/A ratio.22 Thus, compensatory mechanisms may conceal initial deterioration of myocardial function from conventional global measures.

In concordance with previous studies in hospital settings,39 we found that, in the general population, TDI parameters of systolic and diastolic performance were lower in persons with hypertension, diabetes, or IHD (Table 1). The fact that TDI was able to detect these differences in a non-hospitalized population strengthens the diagnostic application of TDI as a technique for early non-invasive detection of impaired myocardial function. Furthermore, it challenges the view that asymptomatic persons with hypertension or diabetes be treated as having normal cardiac function.

In general, subjects with abnormal conventional echocardiography had lower TDI parameters of systolic and diastolic performance than their counterparts with normal conventional echocardiography (Figure 3). Appreciating TDI as a diagnostic method detecting early myocardial changes, this was indeed anticipated. The crucial point, however, is that despite a normal conventional echocardiographic examination (absence of left ventricular hypertrophy, dilatation, ejection fraction <50%, mild or severe diastolic dysfunction, or significant valvular regurgitation or stenosis), TDI continued to show reduced myocardial function in the three exposed groups (Figure 3). Performing the multivariable analyses revealed the same patterns, although not all of the parameters reached statistical significance when including the insignificant interactions between conventional echocardiography and the groups (Table 2). However, such comprehensive statistical subgroup analyses may be fragile due to lack of power and should be interpreted with caution.

LD was lower in the diabetic group compared with controls and the lower mean value of s′ was borderline significant in the multivariable analysis. Conversely, Di Bonito et al.23 observed no significant difference with regard to s′ in patients suffering from diabetes for <4 years compared with controls. Hence, the pathological processes in diabetic cardiomyopathy may not initially be mirrored in s′.

Late peak diastolic velocity, a′, correlates positively with age,20 and adjustment for age showed that there was no difference in mean a′ between the groups with hypertension or diabetes compared with controls. In contrast, a′ was significantly lower in the group with IHD compared with controls. Thus, when e′ declines with increasing age, a′ increases accordingly in controls;20 whereas the decrease in e′ in hypertension and diabetes is not associated with a compensatory increase in a′; the late diastolic performance even decreases further in persons with IHD.

Subjects with hypertension displayed lower systolic and diastolic performance by TDI than those without. In addition to this, myocardial performance evaluated by TDI decreased linearly with increasing blood pressure classes (Figure 4). The Framingham Study has shown that persons with high normal blood pressure have increased risk of developing hypertension24 and cardiovascular disease.25 In this context, it is interesting that TDI reveals impaired left ventricular function already in persons with pre-hypertension, suggesting that TDI may aid in the early identification and follow-up of persons with an increased risk of cardiovascular events. The restricted analysis of persons without hypertension showed that only e′ and E/e′ remained significantly reduced after multivariable adjustment in the pre-hypertension group compared with the normal group, thus suggesting that the diastolic TDI parameters are more sensitive for detecting initial myocardial impairment.

Study limitations

Certain limitations of the present study must be taken into account: (i) The fact that our study sample was predominantly Caucasian limits the generalizability of our findings. (ii) Participants with short-lived or prolonged periods of hypertension, diabetes, and IHD, respectively, were treated similarly in the analyses. (iii) Although colour TDI yields the same mechanical information as pulsed TDI, the comparison of myocardial velocities obtained by the two methods is complicated by the velocities being 20–30% higher when measured by pulsed TDI.26 (iv) We did not measure pulmonary venous flow or mitral inflow at the peak Valsalva manoeuvre and were therefore unable to differentiate between grade 2 (pseudonormal) and normal diastolic function by conventional echocardiography. However, it is unlikely that many of our participants were pseudonormalized without concomitant left ventricular hypertrophy, dilatation, or ejection fraction <50%.

Clinical implications

It is widely acknowledged that cardiac dysfunction in hypertension, diabetes, or IHD is a major risk factor for morbidity and mortality. The present study in the general population shows that TDI parameters of myocardial performance are impaired in hypertension, diabetes, and IHD, independently of the result of conventional echocardiography. This suggests that TDI may aid in the identification of subjects at high risk.

Funding

This study was supported by grants from the Lundbeck Foundation, the Novo Nordisk Foundation, Manager Boennelycke and Wife’s Foundation, Aase and Ejnar Danielsen’s Foundation, and The Danish Heart Foundation (7-10-R60-A1698-B132-22413), Copenhagen, Denmark.

The sponsors had no role in the study design, data collection, data analysis, data interpretation, nor in the writing of the manuscript.

Conflict of interest: P.S. has received honoraria from GE Healthcare (modest level). The remaining authors have no conflicts of interest.

References

View Abstract