Tissue Doppler Imaging for the Assessment of Left Ventricular Diastolic Function

The Impact of Left Ventricular Diastolic Dysfunction on Respiratory Adverse Events in Cardiac Surgery Patients-An Observational Prospective Single-Center Study

BACKGROUND

Left ventricular diastolic dysfunction (LV DD) is the most dominant cause of heart failure with preserved ejection fraction (HFpEF) worldwide. This pathological condition may contribute to postcapillary pulmonary hypertension (pcPH) development. Hypoxemia, often observed in pcPH, may significantly negatively impact the course of hospitalization in patients after cardiac surgery. The aim of our study was to investigate the impact of LV DD on the frequency of postoperative respiratory adverse events (RAE) in patients undergoing Coronary Artery Bypass Grafting (CABG).

METHODS

The left ventricular (LV) diastolic function was assessed in 56 consecutive patients admitted for CABG. We investigated the relationship between LV DD and postoperative respiratory adverse events (RAE) in groups with normal LV diastolic function and LV DD stage I, II, and III.

RESULTS

Left ventricular diastolic dysfunction stage I was observed in 11 patients (19.6%) and LV DD stage II or III in 19 patients (33.9%). Arterial blood partial pressure of oxygen (PaO2) to the fraction of inspired oxygen (FiO2) index during postoperative mechanical ventilation was significantly lower in LV DD stage II or III than in the group with normal LV diastolic function. Patients with DD stage II or III had a higher occurrence of postoperative pneumonia than the group with normal LV diastolic function.

CONCLUSIONS

Left ventricular diastolic dysfunction is widespread in cardiac surgery patients and is an independent risk factor for lower minimal PaO2/FiO2 index during mechanical ventilation and higher occurrence of pneumonia.

Plasma Homocysteine and Cardiovascular Organ Damage in a Population with a High Prevalence of Risk Factors

PURPOSE

It is unclear whether plasma homocysteine (Hcy) has a direct noxious impact on the cardiovascular (CV) system or whether its association with cardiovascular events (CVEs) is mediated by established risk factors. To explore the role of Hcy in CV impairment, the study evaluated cross-sectional relationships between plasma Hcy and indices of CV organ damage together with the associations of these indices with the history of CVEs.

METHODS

In 269 patients with a high prevalence of diabetes, dyslipidemia, and hypertension, the carotid intima-media thickness, ankle-brachial index (ABI), reactive hyperemic index, carotid-femoral pulse wave velocity (cfPWV), left ventricular (LV) mass, and cardiac index were measured.

RESULTS

132 patients had carotid plaque, 31 ABI < 0.90, 126 endothelial dysfunction, 66 increased cfPWV, 125 LV hypertrophy (LVH), 153 decreased cardiac index, and 115 a history of CVEs. Plasma Hcy levels were related to LV mass and ABI, after adjustment for covariates and creatinine. Significantly higher Hcy levels were found in patients with LVH (8.5 [4.4] vs 7.6 [2.8] μmol/L; adjusted P = .001) and ABI < 0.9 (10.4 [3.8] vs 7.9 [3.4] μmol/L; adjusted P = .001) than in those with LV mass and ABI within limits. Hcy levels were comparable between patients with and without carotid plaques, increased arterial stiffness, impaired endothelial, and LV pump function. Within markers of CV organ damage, only LVH was associated with a history of CVEs.

CONCLUSION

This study demonstrated an independent association between Hcy and LV mass as well as between LVH and a history of CVEs and suggests that LVH may represent 1 of the pathophysiologic links between Hcy and CV risk.

Evaluation of cardiovascular risk in stages of gout by a complex multimodal ultrasonography

The aim of our work was to assess ultrasound features of cardiovascular (CV) risk in stages of gout. Cross-sectional complex multimodal ultrasound study of 169 age-matched patients, with similar distribution of arterial hypertension, diabetes mellitus, obesity and chronic renal failure, was divided into four groups: 41 with asymptomatic hyperuricemia, 52 gout without tophi, 42 gouty tophi and 34 controls with osteoarthritis. Parameters independently associated with CV risk were measured: renal resistive index (RRI), left ventricular mass index (LVMi), mitral annulus early diastolic velocity (e'), intima-media thickness (IMT) and common carotid artery resistive index (CCARI). Multivariate analyses were performed to evaluate the impact of gout stages and CV risk factors on ultrasound alterations. Gouty tophi increased the risk of having IMT >0.90 mm with an OR 11.51 (95 % CI 2.32-57.21, p = 0.003), gout without tophi raised the risk with an OR 6.25 (95 % CI 1.37-28.44, p = 0.018), while asymptomatic hyperuricemia had no effect on IMT. The category of CCARI >0.70 was influenced by tophi with an OR 11.18 (95 % CI 2.61-47.83, p = 0.001) and by arterial hypertension with an OR 3.22 (95 % CI 1.11-9.36, p = 0.032). Neither asymptomatic hyperuricemia nor gout without tophi modified the development of abnormally high CCARI. Gout stages had no impact on LVMi, e' and RRI. Tophi are related to worsened ultrasonographic parameters evaluating target organs in gout, relative to earlier stages of the disease. They create a strong risk of carotid arteries' changes even beyond arterial hypertension.

Left atrial function assessed by left atrial strain in patients with left circumflex branch culprit acute myocardial infarction

INTRODUCTION

Although left atrium (LA) has played an important role in diastole, ischemic insult of atrium in acute myocardial infarction (AMI) has not been clearly evaluated.

METHODS

We hypothesized that LA function would be further decreased in AMI patients with a culprit lesion in the left circumflex branch (LCX). This was an observational cohort study in a single university hospital. Echocardiography was performed to evaluate left ventricular diastolic function, LA volume, and LA function. Systolic (LAS ) and late diastolic (LAA ) LA strain were measured using speckle tracking echocardiography.

RESULTS

Sixty-eight AMI patients treated with emergent or urgent percutaneous coronary intervention were enrolled. Global LAS strain was significantly lower in patients with a culprit lesion in the LCX than culprit lesions in other vessels (left anterior descending, 27.3 ± 6.8%; left circumflex, 20.1 ± 8.9%; right coronary artery, 23.3 ± 6.5%; P = 0.007). LA volume index did not differ significantly (P = 0.093). Other clinical and conventional echocardiographic parameters, including Doppler measurements, did not differ significantly.

CONCLUSIONS

Global LAS strain was lower in AMI patients with a culprit lesion in the LCX than those with culprit lesions in other vessels, without any significant difference in LA volume index. The lower global LAS strain might suggest decreased LA function resulting from ischemic insult by AMI with culprit lesions in the LCX.

Subclinical Myocardial Dysfunction in Metabolic Syndrome Patients without Hypertension

BACKGROUND

The aim of this study was to evaluate myocardial function in patients with non-hypertensive metabolic syndrome.

METHODS

We selected metabolic syndrome patients (n = 42) without evidence of hypertension and compared them to age-matched control individuals (n = 20). All patients were evaluated by two-dimensional and tissue Doppler echocardiography including tissue Doppler derived strain and strain rate measurements.

RESULTS

There were no significant differences between the two groups in mitral E and A inflow velocities or the E/A ratio. However, systolic and early diastolic myocardial velocities, and strain rate were significantly lower in patients with metabolic syndrome than in the control group (all p < 0.05). Multiple stepwise regression analyses revealed that age, waist circumference, and systolic blood pressure were independently associated with peak systolic myocardial velocity.

CONCLUSION

These results indicate that metabolic syndrome patients without hypertension may have decrease of myocardial systolic and early diastolic velocities on tissue Doppler imaging, even if they appear to have normal systolic and diastolic function on conventional echocardiography.

Usefulness of mitral annular systolic velocity in the detection of left ventricular systolic dysfunction: comparison with three dimensional echocardiographic data

BACKGROUND

Although the modified Simpson's method is widely used for the assessment of left ventricular ejection fraction (LVEF), it has limitations including relatively high inter- and intra-observer variability and time consuming nature. We want to evaluate whether assessing mitral annular systolic velocity (S' velocity) by tissue Doppler imaging (TDI) can be used to evaluate LV systolic function with comparing LVEF by three dimensional echocardiography (3DE).

METHODS

We examined 3DE and TDI studies of patients between January and August 2008. 3DE LVEF was measured by offline commercial computer software EchoPac PC(R) (GE, Andover, MA, USA). S' velocity was obtained from the medial side with apical four chamber view by pulsed-wave Doppler with TDI.

RESULTS

We included 125 patients (78 males (62.4%), mean age: 57.5+/-13.0 years). The mean S' velocity was 7.7+/-1.9 cm/s and the mean LVEF was 57.2+/-10.4%. The S' velocity measured by TDI showed a linear correlation with LVEF measured by 3DE (r=0.688, p<0.001). Study patients were divided into two groups according to the presence of LV systolic dysfunction: Group I (normal LVEF), n=102 and Group II (LVEF <50%), n=23. For prediction of significant LV systolic dysfunction by the receiver operating characteristic curve according to S' velocity, the optimal cutoff value was 6.8 cm/s. At this cutoff value, the sensitivity and specificity were 94.1% and 87%, respectively.

CONCLUSION

In this study, S' velocity measured by TDI showed a significant correlation with three dimensional LVEF and can be used to detect patients with LV systolic dysfunction.

Usefulness of mitral annulus velocity for the early detection of left ventricular dysfunction in a rat model of diabetic cardiomyopathy

BACKGROUND

Diabetic cardiomyopathy (DMCMP) is characterized by myocardial dysfunction regardless of coronary artery disease in diabetic patients. The features of LV dysfunction in rat model of type 1 DM induced by streptozocin, are variable and controversial. Thus, we tested the usefulness of tissue Doppler imaging in the early detection of ventricular dysfunction in a rat model of DMCMP.

METHODS

Diabetes was induced by intra-peritoneal injection of streptozocin (70 mg/kg) in 8 weeks of Sprague-Dawley rat. Diagnosis of diabetes was defined as venous glucose level over 350 mg/dL 48 hrs after streptozocin injection. Echocardiography was done at baseline and 10 weeks after diabetes induction both in diabetes group (n=15) and normal control (n=10). After echocardiography at 10 weeks, invasive hemodynamic measurement using miniaturized conductance catheter was done in both groups.

RESULTS

Ten weeks after diabetes induction, heart and lung mass indexes of diabetes were larger than those of normal control (3.2+/-0.3 vs. 2.4+/-0.2 mg/g, p<0.001, 5.5+/-1.1 vs. 3.6+/-0.6 mg/g, p<0.001, respectively). In echocardiographic data, s' (2.4+/-0.4 vs. 3.1+/-0.5 cm/s, p<0.001), e' velocity of mitral annulus (2.9+/-0.6 vs. 3.8+/-1.1 cm/s, p<0.001), and E/e' ratio (27.1+/-5.6 vs. 19.7+/-2.6, p<0.001) were impaired in diabetes group. In hemodynamic measurement, there were no differences in ejection fraction, peak dP/dt between the diabetic group and normal control. However, load independent indexes of contractility, the slope of the end-systolic pressure volume relation (0.18+/-0.07 vs. 0.62+/-0.18 mmHg/microL, p<0.001) and preload recruitable stroke work (51.8+/-22.0 vs. 90.9+/-22.5 mmHg, p<0.001) were impaired in diabetic group compared to normal control.

CONCLUSION

In a rat model of diabetic cardiomyopathy, tissue Doppler imaging of mitral annulus can be a good modality for early detection of myocardial dysfunction.