To find out if Doppler myocardial imaging (DMI) can detect early signs of left ventricular (LV) dysfunction in a rat model of diabetic cardiomyopathy.
Eight control and 12 Streptozotocin (STZ)-induced diabetic rats underwent transthoracic echocardiography with high-resolution technology at baseline and 2, 4, 8, 12, and 16 weeks after STZ injection. Radial function was analysed using conventional M-mode, and velocity, strain and strain rate imaging. Longitudinal function was analysed using pulsed Doppler imaging of the mitral annulus.
In the diabetic rats, a significant increase in LV end diastolic and end systolic diameter was measured when compared with controls (P < 0.001). Fractional shortening and LV ejection fraction remained unchanged in both groups. Using DMI, diabetic rats demonstrated a decrease in radial systolic velocity (rate of change: +0.01 vs. –0.003 week–1; P < 0.01) and radial systolic strain rate (+0.003 vs. –0.205 week–1; P = 0.08) of the anteroseptal wall. Histologic examination revealed dilated cardiomyopathy with no signs of fibrosis.
Although LV ejection fraction remained preserved, velocity and strain rate imaging was able to detect radial systolic dysfunction in diabetic rats. The absence of histological signs of fibrosis suggests that other mechanisms play a role in the development of diabetic cardiomyopathy.
Heart transplant assessment includes cardiac output calculation by right heart catheterisation. Real-time 3D echocardiography (RT-3DE), unlike 2D echocardiography, can measure stroke volume without inaccurate geometrical assumptions. The purpose of this study was to assess the feasibility and accuracy of non-invasive RT-3DE cardiac output calculation.
Forty consecutive patients referred for transplant assessment underwent transthoracic RT-3DE. Full volume 3DE data sets were acquired from apical views with the iE33 ultrasound system (Philips Ultrasound, Bothell, USA). Four patients were excluded due to poor image quality. The remaining 36 patients had end-diastolic (LVEDV) and end-systolic (LVESV) left ventricular volumes manually traced, using endocardial detection software. Cardiac output was subsequently calculated: [(LVEDV – LVESV) x heart rate]. Thermodilution derived cardiac outputs, under the same haemodynamic conditions, were used as reference for comparison. There was close correlation between RT-3DE and catheter derived cardiac outputs (r = 0.91, y = 0.86x + 0.45, SEE 0.39 L/min, mean difference from reference –0.06 L/min, SD 0.40 L/min). RT-3DE data analysis took 3 min per case.
This study shows RT-3DE is an accurate method for calculating cardiac output. In patients requiring serial evaluation of cardiac function, this non-invasive test may be preferable to invasive right heart catheterisation.
Patients with asymptomatic aortic stenosis (AS) and abnormal haemodynamic responses to exercise testing are at increased risk of cardiac events. This study assesses the Doppler echocardiographic determinants of a positive exercise test in a cohort of asymptomatic patients with AS.
One hundred and twenty-eight patients with AS underwent quantitative Doppler echocardiographic measurements at rest and during exercise test. Of these patients, 60 had an abnormal response to exercise. Two independent determinants of an abnormal exercise response were selected in multivariate analysis: a larger increase in mean transaortic pressure gradient (P = 0.00014) and a limited contractile reserve—latent left ventricular dysfunction—as indicated by smaller changes in ejection fraction (P = 0.0002). Limiting symptoms were associated with greater increase in mean transaortic pressure gradient, smaller changes in systolic blood pressure and a lower ejection fraction at peak exercise. The increase in pressure gradient was associated with smaller exercise-induced changes in aortic valve area and in ejection fraction and new or worsening mitral regurgitation during exercise.
Abnormal responses to exercise in asymptomatic AS patients are mediated by a larger increase in mean transaortic pressure gradient and/or a limited contractile reserve characterized by an inadequate increase in ejection fraction at exercise.
Our objective was to evaluate regional systolic myocardial contraction properties along the long and short axes of the left ventricle (LV) in patients with isolated LV non-compaction (IVNC).
Pulsed tissue Doppler imaging (TDI) was used to record myocardial velocities along these axes in 25 patients with IVNC (10 asymptomatic–LV ejection fraction [LVEF] ≥ 50%; 15 symptomatic–LVEF < 50%) and 15 healthy controls. In all cases, the systolic velocity pattern featured 2 distinct peaks (SW1, SW2). These peak velocities and the intervals from the electrocardiographic Q wave to each peak (Q-SW1, Q-SW2) were recorded for each axis, and group means were calculated. The asymptomatic group displayed significantly higher long axis SW2 and significantly longer long axis Q-SW1 than the controls. The symptomatic group had significantly lower SW1 and SW2 on both axes and significantly longer short axis Q-SW1 than the asymptomatic group and the controls. Long axis Q-SW1 and short axis Q-SW1 in the symptomatic group were significantly longer than the corresponding control findings, but were not significantly different from the corresponding asymptomatic group findings.
In conclusion, patients with IVNC exhibit distinct systolic myocardial shortening velocities along the long and short axes of the LV. Further, these pulsed TDI findings suggest that asymptomatic patients (those with normal LVEF) have subclinical myocardial dysfunction.
To compare and contrast 3 different echocardiographic methods used to measure left atrial (LA) volume: biplane area length (AL), biplane modified Simpson (SIMP), and prolate ellipse (PE) methods.
A review of consecutive patients who presented to our outpatient echocardiography laboratory for a resting transthoracic study between April 2006 and May 2006 was performed. Echocardiograms were reexamined and LA volume measured using the AL, SIMP, and PE methods. Of 102 consecutive patients evaluated, 97 had a measure of LA volume using all 3 methods. A significant difference in the measurement of mean ± SD LA volume was noted among the 3 different methods: 37 ± 16 mL/m2 for AL, 34 ± 14 mL/m2 for SIMP, and 27 ± 12 mL/m2 for PE. The PE method yielded routinely smaller values compared with either the AL or SIMP method (P < 0.001). Differences increased with increased LA volume. The SIMP method derived consistently smaller (<5 mL/m2) values than those of the AL method, consistent across the full range of LA volumes.
Significant differences exist among these 3 commonly used methods for measuring LA volume. Standardization of the measurement of LA volume is recommended.
This study evaluates a simple echocardiographic rhythm independent expression of left atrial (LA) function, ‘the left atrial function index’ (LAFI).
Quantitation of LA function is challenging and often established parameters including peak A are limited to sinus rhythm (SR). We hypothesized that atrial function could be characterized independent of rhythm by combining analogues of LA volume, reservoir function and LV stroke volume.
Seventy-two patients with chronic atrial fibrillation (CAF) were followed for six months post cardioversion (CV). Thirty-seven age matched healthy subjects were controls. The LAFI = LAEF x LVOT-VTI/LAESVI (LAEF = LA emptying fraction, LAESVI = maximal LA volume indexed to BSA, LVOT-VTI = outflow tract velocity time integral).
The LAFI pre-CV in the CAF group was depressed vs controls (0.10 ± 0.05 vs 0.54 ± 0.17; P = 0.0001). Post-CV, LAFI was lower in persistent AF than in those restored to SR (AF vs SR: 0.08 ± 0.03 vs 0.15 ± 0.08; P = 0.0001), improved progressively in SR and was unchanged when AF persisted.
The LAFI, a simple, rhythm independent expression of atrial function, appears sensitive to differences between individuals in AF and those restored to SR and justifies clinical and investigative applications.
We tested the hypothesis that shortening of diastolic pressure half time (PHT) of left anterior descending (LAD) coronary flow in patients with old reperfused anterior myocardial infarction (MI) is related to the presence of permanent myocardial damage of the reperfused area.
We studied 49 patients divided into: group A: 15 patients with previous anterior MI and evidence of myocardial scar; group B: 10 patients with previous anterior MI and no evidence of myocardial scar and group C: 24 patients without anterior MI. All patients underwent coronary angiography at least 6 months after an index event and any reperfusion procedure. Group A patients had lower PHT (199 ± 62 ms) than group C (377 ± 103 ms, p = 0.0001) and group B (316 ± 154 ms, p = 0.029) patients. No other LAD flow velocity parameter differed among the 3 groups. A PHT value of 265 ms discriminated patients with scarred anteriorwallwith a sensitivity of 79% and a specificity of 94% (0.88, p < 0.001).
Shortening of the LAD flow diastolic PHT in patients with remote, reperfused anterior MI reflects scarred myocardial tissue in the anteroapical wall while patients who maintain diastolic wall thickness after an acute coronary syndrome have PHT similar to patients without anterior MI.
Tissue Doppler imaging has been recently used to evaluate ventricular function in patients with β thalassemia. In clinical practice, serum ferritin is commonly used to assess the severity of iron overload. The aim of this study was to determine which Doppler findings correlated with serum ferritin.
Thirty-one pediatric patients with transfusion-dependent β thalassemia with normal LVFS were evaluated. Seven patients with serum ferritin <2500 ng/ mL, 13 patients with serum ferritin 2500–5000 ng/mL, and 11 patients with serum ferritin >5000 ng/mL were studied. Diastolic dysfunction was absent in all patients with serum ferritin <2500 ng/mL, and was present in all patients with serum ferritin >5000 ng/mL. Deceleration time (DT) has a significant correlation with serum ferritin (r = –0.59, p < 0.0001). Difference of pulmonary vein atrial reversal flow and mitral valve A wave duration (PVAR – MVA) and early ventricular filling velocity to early diastolic myocardial velocity ratio (E/Em) significantly correlated with serum ferritin (r = 0.49, p = 0.006; r = 0.56, p = 0.001, respectively).
Decreased DT, increased PVAR-MVA duration, and increased E/Em ratio reliably reflected severe iron overload in pediatric patients with β thalassemia. Systolic and diastolic LV function is preserved in patients who have serum ferritin <2500 ng/mL.
Three-dimensional echocardiography (3DE) appears to show incremental benefit over two-dimensional echocardiography (2DE), but it's uptake has been slow. We tested attendees before and after an intensive interactive training course to identify its efficacy.
Attendees (n = 35, 23 cardiologists, 12 sonographers) were shown how to use 3DE review software and asked to identify the pathology of five patients (wall motion abnormality, peri-prosthetic mitral regurgitation, subaortic membrane, small ventricular septal defect, submitral stenosis) on 2D and 3D images. In the following one and a half-day interactive teaching course, brief presentations on application of 3DE for assessment of wall motion, valve and congenital abnormalities were followed by review of 3D datasets, during which the attendees made their own interpretations before being shown the optimal viewing strategy. Test cases were not discussed and the test was repeated at the end of the course.
Most attendees (57%) had access but with little or no use of a 3DE system. Three-dimensional echocardiography had no incremental value before training. After training, overall correct responses significantly improved compared with baseline interpretation, although improvement was not the same for all diagnoses. All groups (cardiologists vs. sonographers, inexperienced vs. moderately experienced reviewers) improved similarly.
Incorporation of 3DE into standard practice may be limited by inexperience. An interactive teaching course with rehearsal and direct mentoring appears to overcome this limitation and may improve the uptake of this technique.
Dyspnea is a common indication for pulmonary evaluation but also a common symptom in heart failure. Identification of dyspneic patients with significant LV systolic dysfunction is critical because of high morbidity of untreated heart failure. We sought to determine whether screening patients referred for pulmonary function testing (PFT) using a hand carried ultrasound (HCU) device could identify LV systolic dysfunction.
Forty-nine subjects were recruited from a pulmonary function lab to undergo a brief echocardiographic examination by an internist using a HCU device. All subjects also received an examination with a full-featured echocardiogram machine as a gold standard.
All subjects with normal PFT had normal LV systolic function. Among subjects with abnormal PFT, 6 (15%) had LV systolic dysfunction and the remainder had normal LV systolic function. No subjects with LV systolic dysfunction by full-featured echocardiograms were missed by the HCU (sensitivity 100%, specificity 95%, negative predictive value 100%, positive predictive value 75%).
LV systolic dysfunction is prevalent among patients with pulmonary disease and can be accurately screened for by a physician using a hand carried ultrasound device with subsequent confirmation with complete echocardiography.
To report a case of intracardiac metastasis of malignant melanoma with multiple mobile, large masses in left atrium (LA), left ventricle (LV) and right atrium (RA).
]]>Transesophageal study revealed a round mass arising from the posterior right atrial wall just adjacent to the extrusion of the superior vena cava. The patient subsequently underwent cardiac surgery and a cardiac tumour was excised that proved to be a cardiac myxoma. In this case we present echocardiographic images and the macro- and microscopic view of the right atrial myxoma.
]]>The mass was surgically removed, histology was diagnostic for myxoma, and the patient had an uneventful recovery.
Real-time three-dimensional echocardiography images the entire volume of a mass allowing for accurate measurements in multiple planes, and allowing for real-time evaluation of obstructive effects on ventricular in- or outflow. This case shows how RT3DE and other non-invasive imaging modalities may be used as complementary techniques for evaluation of intracardiac masses.
]]>To evaluate the influence of age on average values of pulsed tissue Doppler recorded at the septal and lateral mitral annulus in a population of healthy subjects and to propose reference values according to different age decades.
Two hundred and forty-six healthy subjects (M/F = 160/86, mean age 40.9 years) underwent Doppler-echocardiography and pulsed tissue Doppler of the septal and lateral mitral annulus. Sm, Em, Am peak velocities were measured at both the annular sides and average values obtained. The ratio of transmitral E peak velocity and average Em peak velocity (lateral Em + septal Em/2) was calculated as an index of left ventricular filling pressure. The population was divided into seven age decades: 10–19, 20–29, 30–39, 40–49, 50–59, 60–69 years and >70 years. Em was progressively reduced and Am increased with increasing age at both the annular sides as well as average values. Sm reduction with advancing age was significant only at the lateral mitral annulus and as average values. Average E/Em ratio was particularly higher in the last three age decades. By multilinear regression analyses, age was the main independent predictor of average Em, Am and E/Em ratio, while heart rate was the most important contributor to average Sm, with the additional contribution of age.
Aging shows an independent impact on average tissue Doppler indexes of septal and lateral mitral annulus in normal subjects. Our data also provide reference values of tissue Doppler average variables for age decades.
Despite its relatively high intra- and inter-observer variability for left ventricular ejection fraction (LV-EF) echocardiography is clinically still the most used modality to assess LV-EF. We studied whether adding a second-generation microbubble contrast agent could decrease this variability.
Forty-eight patients underwent transthoracic echocardiography in second-harmonic mode (SHI) with and without contrast within 5 days after an acute myocardial infarction. LV-EF was determined using the Simpson's biplane method. With contrast intra-observer variability decreased from 12.5 ± 11.5% to 7.0 ± 7.0% (P < 0.001) and inter-observer variability decreased from 16.9 ± 9.9% to 7.0 ± 6.2% (P < 0.001). Bland–Altman analysis confirmed these findings by demonstrating smaller 95% limits of agreement for both the intra- and inter-observer variability when contrast was used. This improvement in intra- and inter-observer variability was seen to a comparable extent in patients with moderate-to-poor and good quality SHI echocardiograms.
Echo contrast significantly improves intra- and inter-observer variability for LV-EF, both in patients with moderate-to-poor and good quality SHI echocardiograms.
To evaluate the accuracy of real-time three-dimensional echocardiography (RT3DE) using a biplane and multiplane method in determining left ventricular (LV) mass compared to cardiac magnetic resonance imaging (CMR).
LV mass was measured in 18 adult patients with congenital aortic stenosis using CMR and echocardiography (M-mode, two-dimensional echocardiography (2DE), and RT3DE). RT3DE data were analysed using a biplane and multiplane method. No geometric assumptions were necessary using the multiplane RT3DE method.
With regard to biplane or multiplane RT3DE, no tendency of over- or underestimation of LV mass was observed. Pearson's correlation coefficients for RT3DE versus CMR were 0.84 and 0.90 for the biplane and multiplane method, respectively. In addition, the accuracy of both RT3DE methods were comparable (Fisher's R-to-Z transformation: Z = 0.69, P = NS). Finally, off-line analysis using biplane RT3DE was significantly faster than multiplane RT3DE (3.8 ± 1.2 vs. 7.8 ± 1.7 minutes, P < 0.001).
Biplane RT3DE provided an accurate estimate of LV mass in patients with concentric left ventricular hypertrophy, which was not improved by multiplane RT3DE. The accuracy and speed of analysis renders biplane RT3DE an attractive tool in daily clinical practice for assessing the degree of LV hypertrophy.
In professional cyclists, typical changes include reversible dilatation of atria and left ventricle (LV), LV hypertrophy but normal diastolic function. Data on long-term outcome are limited.
Of all 134 former Swiss professional cyclists (PC) participating ≥1x in the professional bicycle race Tour de Suisse from 1955 to 1975, 62 (42%) were recruited for a prospective case control study. The PC and a control group of 62 golfers (matched for age, gender, hypertension, present physical activity) were screened [clinical examination, history, echocardiography, measurement of proBNP (normal <227 pg/mL)].
The interval since the last bicycle race as PC was 38 (15–49) years. Average age at exam was equal in controls and PC (66±6 vs 66±7 years; P = 0.73). Percentage of participants undergoing >4 h of endurance training per week was identical (P = 0.72). Total kilometers (km) on the bicycle were higher in PCs with 311,000 (60,000–975,000) than in controls (2500 [0–120,000]; P < 0.0001). PC had larger atrial volume indices (P = 0.002) and tended to have higher LV muscle mass indices (P = 0.07). Multiple regression analysis identified the total number of bicycle km as an independent factor for LV muscle mass. For left atrial size, heart rate at rest, age, years since the last bicycle race and the current hours of endurance training were identified as independent predictors. Long axis function of both ventricles (systolic velocities of mitral and tricuspid annulus) was decreased in PC (P ≤ 0.04). There were signs of diastolic dysfunction with lower annular E' and A' velocities. ProBNP levels were comparable in both groups (P = 0.21).
Among former PC, there seems to be incomplete cardiac remodelling with differences in systolic and diastolic function between former PCs and controls in the long time follow-up. Former high level endurance training may have a persisting impact on cardiac size and function.
Since colour tissue Doppler (CTD) has been shown to underestimate myocardial velocity, we sought to compare CTD with spectral tissue Doppler (STD) and establish agreement and corresponding thresholds for clinical applications.
We included 52 consecutive patients with sinus rhythm referred for echocardiographic assessment. Analysis involved a commercially available echosonographer (Vivid 7, GE-Vingmed) and the Echopac system for offline assessment. Myocardial velocities were recorded by STD and CTD in a 4-chamber apical view.
CTD values were lower than those measured by STD: 6.0 ± 2.5 versus 8.2 ± 2.8 for Ea; 5.5 ± 2.3 versus 7.9 ± 2.9 for Aa, and 5.4 ± 2.0 versus 7.7 ± 2.4 for Sa (P < 0.001 for all). CTD overestimated the E/Ea: 14.7 ± 7.6 versus 10.1 ± 4.1, P < 0.001. Reliability between the two methods was low to moderate: kappa values ranged from 0.33 ± 0.10 to 0.57 ± 0.12. CTD thresholds corresponding to usual STD thresholds were calculated, but reliability was not significantly increased, except for the E/Ea ratio. By using continuous values, the ability of the Ea, Sa and E/Ea to predict the presence of heart failure in this sample was similar whatever the method.
CTD consistently underestimates myocardial velocity values and overestimates E/Ea. A shift of thresholds between the two methods is not sufficient to obtain good agreement, except when measuring the E/Ea ratio.
The left internal mammary artery (LIMA) is the conduit of choice for revascularization of coronary arteries and its popularity further increases in the era of mini-invasive coronary surgery. The aim of this study was first, to assess the accuracy of CDUS in predicting the LIMA graft dysfunction as compared to angiography, and secondly, to correlate the postoperative status of the LIMA graft with preoperative coronary artery stenosis severity of the bridged lesion.
We examined 111 patients (pts) by colour-duplex ultrasound after myocardial revascularization by LIMA bypass (3.8 ± 3.2 years after revascularization). LIMA was detected from the left supraclavicular approach at rest using the 7.5 MHz linear transducer. The ultrasound results were compared to contemporaneous angiography. The LIMA bypass patency was correlated with the preoperative coronary artery stenosis severity.
The LIMA was detected by ultrasound in 92.8% (103) pts. At angiography, LIMA was patent and functional in 85 pts (76.6%, group A); in 25 subjects LIMA was stenosed or dysfunctional (22.5%, group B). In one patient the coronary subclavian steal syndrome was detected (0.9%). Haemodynamically moderate stenosis (50–60% by preoperative quantitative coronary angiography) was grafted in 5 pts of group A (6%), but in 10 pts of group B (40%) (P < 0.0001 vs group A). A peak systolic to peak diastolic velocity ratio (SDVR) of <2.0 yielded optimal accuracy to detect the absence of LIMA bypass dysfunction with a negative predictive value of 95%.
1. Revascularization of angiographically moderate coronary lesions is associated with a higher risk of postoperative graft dysfunction. 2. Colour-duplex ultrasound is a useful non-invasive tool for the postoperative follow-up of pts with a LIMA graft.
Diastolic tissue Doppler (TD) parameters allow prediction of patients with hypertrophic cardiomyopathy (HC) at risk of sudden death, ventricular tachycardia, or cardiac arrest. The aim of this study was to assess the value of TD imaging in predicting the clinical course of patients with HC.
Eighty-six HC patients were prospectively included in the study and followed-up for clinical endpoints (cardiovascular death or hospitalization due to worsening of heart failure symptoms). Patients with clinical endpoints (n = 25) had larger left atrium diameters, thicker left ventricle (LV) walls, more often LV outflow obstruction and lower TD velocities of LV. LV outflow tract obstruction (r=0.54, R²=0.29, P<0.03) and LV lateral mitral annular systolic tissue Doppler velocity (LMSa) (r=0.50, R²=0.25, P<0.0001) were found to be independent predictors for clinical endpoints in forward stepwise regression. The best value of LMSa with the highest sensitivity (75%) and specificity (88%) was 4 cm/s for predicting clinical endpoints. Patients with LMSa velocities > 4 cm/s were significantly free of clinical endpoints.
In conclusion, LMSa seems to be a reliable parameter that can be used in predicting the HC patients at risk for clinical deterioration or death at long-term follow-up.
Benzocaine induced methemoglobinemia is an uncommon, potentially fatal condition.
A 44-year-old woman with a history of hepatitis C and intravenous drug use was referred for transesophageal echocardiography for bacteremia evaluation. During induction of topical anesthesia with benzocaine spray she became cyanotic. Pulse oximetry revealed marked desaturation (75%) but was discordant from arterial blood O2 saturation (99%). Due to clinical suspicion, methemoglobin level was measured and noted to be 69%. The patient was treated with 2 mg/kg of methylene blue intravenously with resolution of her symptoms.
Physicians using topical anesthesia in endoscopic suites should be aware of this rare, potentially life-threatening treatable condition. High clinical suspicion and availability of methylene blue in endoscopy suites will facilitate prompt diagnosis and treatment.