Direct measurement of left ventricular outflow tract by transthoracic real-time 3D-echocardiography increases accuracy in assessment of aortic valve stenosis.

BACKGROUND: Evaluation of aortic valve stenosis is a major clinical application of echocardiography. The widely employed continuity equation requires determination of the left ventricular outflow tract (LVOT) area. We aimed at testing whether direct area measurement in a volume data set is superior to conventional calculation from the LVOT diameter. METHODS: We performed LVOT measurement in 20 normal subjects and 83 patients with moderate to severe aortic stenosis with a transthoracic real-time three-dimensional echocardiography (3D-TTE) technique in two systolic frames. The off-line 3D-evaluation allows full choice of section planes within the acquired volume data set. The aortic valve area was calculated from systolic LVOT areas. These results were compared to area values obtained by M-mode LVOT-diameters (area=pi(*)(d/2)(2)). In addition, the calculated aortic valve orifices were compared to invasive measurements or direct planimetry in the transthoracic or transesophageal examination. RESULTS: Two independent observers found a reduction in LVOT area during systole (p<0.001). Often a more ellipsoid-like shaped LVOT resulted at end-systole which was shown by a reduction (p<0.001) of the LVOT longitudinal to oblique axis ratio. 3D-TTE determination of aortic valve orifice areas (mean difference: -0.04+/-0.09 cm(2)) showed a lesser deviation from the invasively or planimetrically measured areas than conventionally calculated LVOT areas (mean difference: -0.1+/-0.1 cm(2)) using the continuity equation (p<0.001). CONCLUSIONS: The tested transthoracic 3D-echocardiography technique offers non-invasive measurement of the LVOT and aortic valve area based on the continuity equation during systole and thus improves accuracy and, additionally, agreement of aortic valvular area determination with invasive and direct measurements.

Prognostication of post-infarct chronic heart failure: superiority of clinical assessment vs. cardiopulmonary and left ventricular function analysis.

BACKGROUND: Prognostication of congestive heart failure post-myocardial infarction (MI) is important for decision making. We sought of a head-to-head comparison between the prognostic implication of clinical, cardiopulmonary, and left ventricular (LV) function assessment. METHODS: Retrospectively, 100 consecutive post-MI patients (MI history 1418+/-1668 days ago) were stratified by NYHA functional classification system, cardiopulmonary exercise testing (CPX) [oxygen consumption at maximal exercise (VO(2max)) and at the anaerobic threshold (VO(2AT)) resulting in the Weber classification], and LV function analysis by M-mode and two-dimensional echocardiography [LV end-diastolic and -systolic diameter index (LVDDI and LVSDI), shortening fraction (%D), and LV end-diastolic and -systolic volume index (EDVI and ESVI), LV ejection fraction (EF)]. Patients were controlled by phone call 1470+/-607 days later. RESULTS: There was only a modest correlation between NYHA and Weber classes (r=0.402) and no correlation between VO(2max) and ESVI (r=0.080) nor between NYHA and ESVI (r=0.174). Several parameters (ESVI, LVDDI, LVSDI, %D) could discriminate NYHA classes to a higher significance (p=0.05; 0.0008; 0.0002; 0.04) than the Weber classes (n.s.; p=0.03; n.s.; n.s.). The following parameters could significantly differentiate quartiles in a log-rank analysis (Kaplan-Meier survival curves): NYHA classes (p=0.0001), Weber classes (p=0.069), EDVI (p=0.004), ESVI (p=0.0001), EF (p=0.002), LVDDI (p=0.002), LVSDI (p<0.001) and %D (p<0.001). Multivariate analysis isolated the following three parameters implying decreasing, independent prognostic information: NYHA classes (p=0.001), ESVI (p=0.003), and Weber classes (p=0.040). CONCLUSIONS: In post-MI patients the thorough clinical assessment according the NYHA functional classification system implies higher prognostic information than more objective measures. This should be considered especially in primary care and should lessen the dependence on costly and expertise-dependent technical investigations.

Chronic development of ischaemic mitral regurgitation during post-infarction remodelling.

BACKGROUND/AIMS: Mitral regurgitation (MR) following myocardial infarction (MI) may be a (sub)acute complication which independently predicts reduced survival. We sought to evaluate the chronic development of MR as potential consequence of left-ventricular (LV) remodelling, the latter being a long-term process. METHODS AND RESULTS: Retrospectively, 103 post-MI patients were included according to a standardised Doppler echocardiogram <3 months following MI (20 +/- 25 days post-MI) and a follow-up examination >6 months after the first examination (5.1 +/- 3.1 years post-MI). Patients were clinically followed up for 7.6 +/- 2.7 years. Group I patients were defined as those showing new development or deterioration in one of three grades of MR, and group II those without this criterion (MR grade acute 0.17 vs. 0.27, p = 0.7, and chronic 1.53 vs. 0.19, p < 0.0001). Patient characteristics were similar in respect of age, gender, size and location of infarction. However, group I patients had coronary artery disease with more vessels involved. With regard to echocardiographic parameters of significantly enlarged LV chamber size in group I vs. group II, the significant decrease in LV performance was more pronounced and occurred concomitant with a higher degree of symptomatic congestive heart failure and greater need for heart failure medications in group I. Mortality in group I patients was 39 versus 9% in group II patients (p = 0.0002), approximating an odds ratio of 6.4697 (95% confidence interval: 2.211-18.931). CONCLUSION: First of all, this retrospective study indicates that MR may be detected in patients after MI during a long-term follow-up most probably due to geometric distortions of LV remodelling resulting in a significantly higher mortality. Since this process is known to become irreversible at a certain point, serial echocardiography may help to detect MR in post-MI patients and thus pave the way for appropriate treatment.

Assessment of the tricuspid valve morphology by transthoracic real-time-3D-echocardiography.

AIM: To demonstrate the feasibility of transthoracic three-dimensional real-time echocardiography (3D-TTE) supplemental to routine assessments of the tricuspid valve and to analyze interrater agreement. METHODS: Twenty healthy subjects and 74 patients with right ventricular failure were examined with conventional 2D and additionally 3D-TTE (SONOS 7500, Philips, Netherlands). The 3D exams were performed and recorded by one of two raters. The recordings were evaluated offline and independently by both raters for visualization of morphological and functional features of the tricuspid valve according to a subjective 3-point scale. Statistical analyses were performed for interrater agreement and for comparison of imaging quality between the two study groups. In addition, we present an illustrative case report. RESULTS: Visualization of the spatial relationship between the tricuspid valve and vicinal structures, of the commissures, the orifice, and entirety of valve depiction were better in the ventricular failure group as compared to the control group. Annular dimensions were equally assessable in both groups, leaflet thickness and mobility were not significantly different. Interrater agreement on assessability was slight for leaflet thickness, fair for leaflet mobility and orifice area, and good for the remaining features. The 3D-TTE exam including offline evaluation took 6.5 minutes on average and maximally 14 minutes. CONCLUSION: 3D-TTE of the tricuspid valve can be performed in addition to routine 2D echocardiography within a reasonable time and with high assessability of important features in patients with right ventricular failure. Interrater agreement was fair to good overall. Thus, its feasibility may encourage prospective studies on its potential for more detailed noninvasive diagnosis and preoperative planning.

Cardiovascular hemodynamics and exercise tolerance in thyroid disease.

The heart is an organ sensitive to the action of thyroid hormone, and measurable changes in cardiovascular performance are detected with small variations in thyroid hormone serum concentrations. Most patients with thyroid disease experience cardiovascular manifestations, and the most serious complications of thyroid dysfunction occur as a result of cardiac involvement. The increased metabolic state and oxygen consumption that occur in hyperthyroid patients require an increased supply of oxygen and removal of metabolic products from the periphery. This is accomplished by increasing the cardiac output to meet the needs of the periphery. Circulation time is decreased in hyperthyroid patients, and a lowered arterial resistance and increased venous resistance promote the return of blood to the heart. Thyroid hormones may significantly decrease the strength of respiratory and skeletal muscles and affect regulatory mechanisms of adaptation to incremental effort. In hyperthyroidism, cardiovascular exercise testing and analysis of respiratory gas exchange demonstrate low efficiency of cardiopulmonary function as well as impaired chronotropic, contractile, and vasodilatatory reserves, which are reversible when euthyroidism is restored. During exercise, the increment (delta) of minute ventilation (respiratory rate x tidal volume), and oxygen pulse (oxygen uptake per heart beat) are significantly lower in dysthyroidism versus euthyroidism. Especially in older patients with thyroid dysfunction, markedly reduced workload, delta ejection fraction, and delta heart rate, both at the anaerobic threshold as well as at maximal exercise, are observed. In thyrotoxicosis, mitochondria oxidative dysfunction during exercise mostly causes intracellular acidosis, whereas in hypothyroidism, inadequate cardiovascular support appears to be one of the principal factors involved. These abnormalities partly explain why subjects with dysthyroidism are intolerant to exertion. Thus, in thyroid disease, both cardiac structures and function may remain normal at rest, however impaired cardiovascular and respiratory adaptation to effort becomes unmasked during exercise.

Improvement of tricuspid regurgitation after pulmonary thromboendarterectomy.

BACKGROUND: For patients with chronic thromboembolic pulmonary hypertension who undergo pulmonary thromboendarterectomy (PTE) it has not yet been systematically investigated how operation affects the severity of tricuspid regurgitation (TR). This study sought (1) to evaluate the extent of TR reversibility after operation, (2) to identify potential predictors of the reversibility of TR, and (3) to investigate the influence of geometric and hemodynamic alterations on the extent of TR severity. METHODS: Thirty-nine patients (55+/-12 years) undergoing PTE without tricuspid valve repair were investigated before and 13+/-8 days after operation by Doppler color flow mapping. Geometry of the tricuspid valve as well as right ventricular size and function were determined with echocardiography. Mean pulmonary arterial pressure was determined invasively. RESULTS: After PTE, mean pulmonary arterial pressure was significantly lower (48+/-10 versus 25+/-7 mm Hg, p < 0.05). Most of the patients had a distinct reduction of TR, and the improvement trend showed on the severity scale: number of patients with 4+TR (23 --> 4), 3+TR (12 --> 12), 2+TR (2 --> 13), and 1+TR (2 --> 10). Examination after PTE revealed profound reduction of right ventricular size and annulus diameter, with a normalization of the valvular geometry. However, none of the study variables were useful as indicators of the postoperative outcome. CONCLUSIONS: After PTE without additional valve repair most patients show significantly reduced severity of TR soon afterward; the very few cases in which TR does not improve remain unidentifiable before operation. Our recommendation is consequently to refrain from additional tricuspid repair in patients undergoing PTE.

Assessment of cardiac performance using Tei indices in patients undergoing pulmonary thromboendarterectomy.

BACKGROUND: This study was designed to evaluate left and right ventricular performance using Tei indices in patients with severe chronic thromboembolic pulmonary hypertension undergoing pulmonary thromboendarterectomy (PTE). The Doppler-derived indices are easily measurable indicators of ventricular function based on nongeometric assessment, which helps overcome some of the difficulties entailed in the geometric assessment of left ventricular (LV) and right ventricular (RV) function in pulmonary hypertension. METHODS: The indices were derived for 24 patients (aged 54+/-14 years) before and after PTE. Calculation of these indices was based on the duration of two time intervals using the formula (A - B)/B, where A is the interval between cessation and onset of mitral inflow (or tricuspid inflow) and B is LV or RV ejection time. In addition, LV and RV end-diastolic and end-systolic chamber areas were determined using two-dimensional echocardiography, and systolic function was calculated. Mean pulmonary artery pressure was determined invasively. RESULTS: PTE led to a significant reduction of mean pulmonary artery pressure (46+/-10 versus 25+/-6 mm Hg; p < 0.05). LV and RV indices were abnormally high before surgery, declined significantly afterwards, and then almost matched normal values (0.61+/-0.26 versus 0.37+/-0.18; p < 0.05 and 0.55+/-0.22 versus 0.37+/-0.13; p < 0.05). Geometric assessment of the left and right ventricle also showed impaired systolic function before PTE, with significant improvement after surgery. CONCLUSIONS: LV and RV Tei indices allow a quantitative assessment of ventricular function in patients undergoing PTE. Lower indices after surgery reflect an improvement of the previously impaired cardiac function. Our results emphasize the value of PTE in the treatment of chronic thromboembolic pulmonary hypertension.

Cardiac involvement in thyroid hormone resistance.

To analyze the cardiovascular alterations thought to occur in resistance to thyroid hormone (RTH), cardiac involvement in 54 patients with RTH was investigated with the help of two-dimensional and Doppler echocardiography. Data from 41 of 54 adult subjects with RTH were also compared with those of 24 and 20 cases with hyperthyroidism (H) and hypothyroidism (h), respectively, as well as 22 healthy euthyroid controls (C). With respect to the type of mutations, no correlation was found between cardiovascular features and genotype. Compared with affected adults, children with RTH showed markedly higher serum free T3 (FT3), free T4 (FT4), and baseline TSH concentrations. Compared with healthy children of comparable age, RTH children had significantly higher heart rate and lower left ventricular (LV) ejection fraction (P = 0.006). Also, higher heart rate and FT4 as well as shorter diastolic relaxation of the myocardium (all P = 0.001) between RTH subjects with and without thyrotoxic cardiovascular features were found. Cardiac symptoms (palpitations, 32% vs. 71%) and signs (sinus tachycardia, 26% vs. 79%; atrial fibrillation, 6% vs. 17%) were significantly less frequent in RTH vs. H (all P = 0.001). Compared with C and h, heart rate, cardiac output, stroke volume, and systolic aortic flow velocity were strongly increased in RTH (all P = 0.0001) and H, although ejection (P = 0.0012) and shortening (P = 0.0001) fractions of the LV were markedly lower in RTH vs. H. Diastolic parameters, such as isovolumic relaxation (P = 0.0001) and deceleration time (P = 0.013), were shorter in RTH vs. h and C. In RTH, positive correlations between FT3 and heart rate, and between FT4 and LV ejection fraction were observed, whereas negative correlations between both FT3 and FT4 and isovolumic relaxation were noted. In conclusion, these findings indicate a modulated hyperthyroid effect on cardiac systolic and diastolic function of the myocardium in RTH, whereas other parameters, such as ejection and shortening fractions of the LV, systolic diameter, and LV wall thickness, were comparable to C. Differences in term of cardiovascular changes were smaller between the RTH and C groups than the RTH and the H or h groups. Thus, an incomplete cardiac response to thyroid hormone is present in RTH.

Improved Assessment of Pathological Regurgitation in Patients with Prosthetic Heart Valves by Multiplane Transesophageal Echocardiography.

The aim of this study was to evaluate the diagnostic increment of individually optimized axes in the assessment of pathological prosthetic valve regurgitation. Forty-two patients with pathologically regurgitant prostheses in the aortic (n = 21), mitral (n = 15), and tricuspid (n = 6) positions were examined by multiplane transesophageal echocardiography. The investigation was performed utilizing the transverse axis first, the longitudinal axis second, and the intermediate axes afterwards. The presence of regurgitation, the differentiation between trans- and perivalvular origin, and the localization of perivalvular leakages at the sewing ring were evaluated. Findings in the biplane and intermediate axes were compared to surgery or autopsy in all patients. There was slightly higher detection rate for aortic prosthetic regurgitation using the intermediate axes than the biplane axes. The intermediate axes revealed significantly fewer differences to the morphological control than the biplane axes with regard to the differentiation of peri- and transprosthetic aortic regurgitation and to the localization of a periprosthetic aortic regurgitant origin. The intermediate axes provided significantly better agreement to surgery/autopsy than the biplane axes regarding the localization of the origin of mitral periprosthetic regurgitation. Morphological visualization of the perivalvular gap adds important information on the precise localization of the regurgitant origin. The pathological gap was visualized significantly more often using the intermediate than the biplane axes in all types of prostheses. The data in this study therefore suggest that multiplane transesophageal echocardiography is superior to biplane transesophageal echocardiography in the assessment of pathologic prosthetic regurgitation.

Quantitative Tissue Doppler Echocardiography: Physiological Nonuniformity of Left Ventricular Transmural Myocardial Wall-Motion Velocities and Gradients.

Tissue Doppler echocardiography (TDE) is a new method by which transmural myocardial function can be studied noninvasively. In order to investigate physiology and reproducibility, 24 young, healthy volunteers were examined by M-mode TDE. Nonuniformity of transmural tissue layer velocities became apparent: Subendocardial and subepicardial velocities of the anteroseptal myocardial wall (AW) were 3.5 +/- 0.7 and 1.3 +/- 0.5 cm/sec (P < 0.0001, t-test), whereas in the posterolateral wall (PW) values of 3.6 +/- 0.6 and 1.2 +/- 0.4 cm/sec (P < 0.0001, t-test), respectively, were revealed. The ratios, termed "myocardial velocity gradients" as a new indicator of left ventricular performance, were 3.1 +/- 1.0 and 3.4 +/- 1.1, respectively. AW and PW did not differ (N.S.). Tolerance borders did not overlap, and intraobserver variability did not reach intersubject variability (P < 0.0001, F-ratio test). TDE provides new and more sophisticated insights into left ventricular performance. It seems to be accurate and reliable and therefore worth introducing into the clinical arena.