Left ventricular volumes and ejection fraction by single plane two-dimensional apex echocardiography

Three-Dimensional Echocardiographic Evaluation of the Heart Chambers: Size, Function, and Mass

The major advantage of three-dimensional (3D) ultrasound imaging of the heart is the improvement in the accuracy of the echocardiographic evaluation of cardiac chamber volumes, which is achieved by eliminating the need for geometric modeling and the errors caused by foreshortened 2D views. In this article, we review the literature that has provided the scientific basis for the clinical use of 3D ultrasound imaging of the heart in the assessment of cardiac chamber size, function, and mass, and discuss its potential future applications.

Atherosclerosis of the descending aorta predicts cardiovascular events: a transesophageal echocardiography study

Purpose

Previous studies have shown that atherosclerosis of the descending aorta detected by transesophageal echocardiography (TEE) is a good marker of coexisting coronary artery disease. The aim of our study was to evaluate whether the presence of atherosclerosis on the descending aorta during TEE has any prognostic impact in predicting cardiovascular events.

Material and Methods

The study group consisted of 238 consecutive in-hospital patients referred for TEE testing (135 males, 103 females, mean age 58 +/- 11 years) with a follow up of 24 months. The atherosclerotic lesions of the descending aorta were scored from 0 (no atherosclerosis) to 3 (plaque >5 mm and/or "complex" plaque with ulcerated or mobile parts).

Results

Atherosclerosis was observed in 102 patients, (grade 3 in 16, and grade 2 in 86 patients) whereas 136 patients only had an intimal thickening or normal intimal surface. There were 57 cardiovascular events in the follow-up period. The number of events was higher in the 102 patients with (n = 34) than in the 136 patients without atherosclerosis (n = 23, p < 0.01). The frequency of events was in close correlation with the severity of the atherosclerosis of the descending aorta. Fifty percent of the patients with grade 3 experienced cardiovascular events. Excluding patients with subsequent revascularization, the multivariate analysis only left ventricular function with EF < 40% (HR 3.0, CI 1.3–7.1) and TEE atherosclerotic plaque >=2 (HR 2.4, CI 1.0–5.5) predicted hard cardiovascular events.

Conclusion

Atherosclerosis of the descending aorta observed during transesophageal echocardiography is a useful predictor of cardiovascular events.

Role of the central endogenous opiate system in patients with syndrome X

BACKGROUND

To evaluate the role of the endogenous opioid system (EOS) in abnormal pain perception in patients with syndrome X, we used a neuroendocrine approach, evaluating plasmatic luteinizing hormone (LH) changes after naloxone, a competitive antagonist of opioid receptors able to unblock tonic EOS inhibition on gonadotropin release. Thus LH response to naloxone test indicates the central EOS activity on hypothalamic luteinizing hormone-releasing hormone (LH-RH) inhibitory opioid receptors.

METHODS

Ten patients with syndrome X, 10 age-matched male patients with coronary artery disease (CAD), and 10 normal subjects were analyzed. Naloxone tests were performed between 8 and 9 am. Basal beta-endorphin and LH levels were determined on 4 blood samples at 20-minute intervals; after naloxone (0.1 mg/kg intravenously in 4 minutes), LH was measured on 8 samples at 15-minute intervals. In all patients the test was also performed after LH-RH administration. Anginal pain on exercise testing was subjectively scored on a 1 to 10 analogic scale and wall motion abnormalities were quantified by a wall motion score index.

RESULTS

Significant differences were found in LH release after naloxone (CAD 260.3 +/- 42.6 vs syndrome X 151.6 +/- 48.5 mIU/mL, P <.05), angina score (CAD 5.5 +/- 1.3 vs syndrome X 7.2 +/- 1.7, P <.05), and wall motion abnormalities (CAD 3.6 +/- 1. 2 vs syndrome X 2.8 +/- 1.9, P <.05).

CONCLUSIONS

The reduced LH release after naloxone in syndrome X, with a normal LH-RH response, suggests a lower central EOS activity, which may be related to the higher anginal pain perception.

Long-term effects of angiotensin-converting enzyme inhibitors and calcium antagonists on the right and left ventricles in essential hypertension

To compare the effects of chronic antihypertensive treatment on left and right ventricular structure and function, 24 patients with mild to moderate, never-treated hypertension were randomized to receive fosinopril (20 mg daily) or amlodipine (10 mg daily) for 12 months. At baseline and subsequently at the end of third, sixth, and twelfth months, each patient underwent an integrated echocardiographic study and noninvasive ambulatory blood pressure monitoring. Both drugs significantly reduced blood pressure, casual or monitored (p < 0.01), and left ventricular mass index (from 125 +/- 32 to 100 +/- 12 gm/m2 [p < 0.02] with amlodipine and from 106 +/- 18 to 89 +/- 10 gm/m2 [p < 0.02] with fosinopril). The decrease in left ventricular mass was essentially caused by a reduction of ventricular thickness. Free right ventricular wall thickness was also lowered in both groups, more consistently with amlodipine (from 8.0 +/- 2.1 to 6.4 +/- 0.8 mm; p < 0.01), without an increase in plasma natriuretic peptide and insulin concentrations or heart rate. With both treatments, the decrease in ventricular mass was not associated with impairment of systolic function, whereas a trend toward an improvement of Doppler echocardiographic indexes of biventricular diastolic function was observed. In conclusion, both amlodipine and fosinopril induced similar qualitative effects on anatomy and function of both ventricles. The clinical meaning of these observations must be defined further by means of adequately sized prospective trials.

Prognostic evaluation of patients after myocardial infarction: incremental value of sestamibi single-photon emission computed tomography and echocardiography

BACKGROUND

This study compares the prognostic value of 99mTc-labeled methoxyisobutyl isonitrile (MIBI) single-photon emission computed tomographic (SPECT) imaging, echocardiography, and other clinical and laboratory prognostic factors in the long-term risk stratification of patients with stable uncomplicated infarcts.

METHODS AND RESULTS

Ninety-one consecutive patients affected by a first myocardial infarction without serious complications were enrolled. After at least 3 months from the infarction, they were submitted to stress-rest MIBI SPECT and rest echocardiography. Eighty-six patients completed a follow-up of at least 4 years (range 48 to 72 months; mean 55 months). By univariate (log-rank test) and multivariate analysis (Cox proportional hazards model), the main clinical, electrocardiographic, scintigraphic, and echocardiographic findings were evaluated and correlated statistically with the incidence of ensuing cardiac events. Twenty-five patients had cardiac events during the follow-up (four cardiac deaths, four myocardial infarctions, and 17 cases of unstable angina). At the multivariate analysis, the presence of reversible defects on MIBI SPECT (p = 0.008 and relative risk [RR] = 7.09), the wall motion score index, and the ejection fraction at echocardiography (respectively, p = 0.010, RR = 3.67, p = 0.036, and RR = 3.12), and stress angina (p = 0.007 and RR = 3.40) were significant and independent prognostic factors.

CONCLUSIONS

In our long-term follow-up, MIBI SPECT and echocardiography appeared to be significant and independent prognostic tools in the risk stratification of patients with stable, uncomplicated infarcts, furnishing complementary information. The reversibility of MIBI defects appeared the best indicator for a bad prognosis.

Quantification of left ventricular function with an automated border detection system and comparison with radionuclide ventriculography

Quantification of 2-dimensional echocardiograms with a recently developed automated border detection (ABD) system provides on-line estimation of left ventricular (LV) function. Previous studies showed that short-axis cavity area measurements with the ABD system approximate manually traced cavity areas obtained with conventional 2-dimensional echocardiography. Further clinical validation needs a comparison of LV function between the ABD system and established methods. Fractional area change and ejection fraction measured by the ABD system were compared with ejection fraction measured by radionuclide ventriculography. Echocardiographic measurements were obtained from LV short-axis views at the level of the papillary muscles. Calculation of ejection fraction by the ABD system was based on an algorithm using a modified ellipsoid model. Forty-six patients underwent echocardiography on the same day as radionuclide ventriculography. Patients were included in the study if > or = 75% of the endocardium was visualized with conventional 2-dimensional echocardiography. Twenty-seven of 46 patients (59%) had a technically adequate, conventional echocardiogram. Fractional area change with the ABD system was highly correlated with ejection fraction from radionuclide ventriculography (r = 0.92; SEE 8.4%). Ejection fraction determined by the ABD system and radionuclide ventriculography also showed a strong linear relation in the 23 patients without severe wall motion abnormality (r = 0.90; SEE 9.5%). It is concluded that LV function measurements by the ABD system and radionuclide ventriculography have a strong linear relation.

Myocardial contractility and performance capacity after magnesium infusions in young healthy persons: a double-blind, placebo-controlled, cross-over study

To evaluate the effect of intravenous magnesium (Mg) treatment on the inotropic state of the heart and maximal work capacity, 9 healthy volunteers were entered in a double-blind, placebo-controlled, cross-over study. Separated by an interval of three weeks, the volunteers were tested twice, each time randomly allocated to receive either an intravenous injection of 10 mmol magnesium chloride dissolved in 100 ml isotonic sodium chloride or placebo of isotonic sodium chloride only. Before and after each infusion myocardial inotropism was evaluated by echocardiography. Mitral-septal distance (MSA) was used as a measure for ejection fraction. On each test day an ergometer bicycle exercise test was performed, and maximal work capacity was calculated. Magnesium treatment reduced the MSA (from 4.2 to 2.9 mm, p = 0.07), while no difference was found after placebo treatment. Likewise, a tendency toward increasing fractional shortening after magnesium treatment was detected, although this difference was not statistically significant (p = 0.1). No difference in maximal work capacity between the magnesium and placebo periods was found. Serum magnesium concentrations and placebo periods was found. Serum magnesium concentrations rose significantly after the infusions (from 0.82 to 1.38 mmol/l, p less than 0.001). It is concluded that intravenous magnesium does not exert a negative inotropic effect on the myocardium as previously stated. On the contrary, we found a tendency toward a positive inotropic effect. However, the observed differences are of borderline statistical significance and a more extended study, employing invasive measurements of cardiac inotropism appears to be necessary.

Measurement of left ventricular volume using single-photon emission computed tomography

A count-based method for measuring left ventricular (LV) volume using technetium-99m-labeled red cells and ungated single-photon emission computed tomography is described. The tomographic slices were used to determine the counts per milliliter in the center of the left ventricle and total LV counts, which were used to derive mean LV volume. End-diastolic and end-systolic volumes were calculated from the mean volume using the LV time-activity curve from planar gated blood pool images. Phantom evaluation with simulated LV volumes (50 to 400 ml) in air, in a phantom filled with water, with 10% background, and with a simulated right ventricle, showed excellent accuracy. For clinical validation, 30 patients underwent electrocardiographically gated planar and nongated tomographic acquisition of the cardiac blood pool followed by single-plane cineangiography. For end-diastolic and end-systolic volumes combined, the correlation with cineangiography showed a standard error of the estimate (SEE) of 24 ml and 14 ml, respectively. Mean intra- and interobserver deviation was 12 ml and 14 ml (SEE 13 ml and 16 ml), respectively. It is concluded that this noninvasive count-based technique, requiring no assumptions regarding LV geometry, is an accurate and reproducible way to measure LV volume.

Measurement of left ventricular ejection fraction after acute myocardial infarction. A serial cross sectional echocardiographic study

Left ventricular ejection fraction was assessed by biplane cross sectional echocardiography in 65 patients with a first acute myocardial infarction on the first day. In 30 patients (group 1) measurements were repeated on the third day and in another 35 patients (group 2) at three months. Changes in ejection fraction of 0.05 or less were arbitrarily called insignificant. In group 1 only two patients showed a decrease of more than 0.1 between days 1 and 3, and both had an enzymatically confirmed infarct extension. The remaining patients had no complications. In group two 11 patients had decreases of more than 0.1 between day 1 and three months: three of them had an enzymatically confirmed reinfarction (perioperative in one) and four a possible reinfarction, and in two an angiographically confirmed left ventricular aneurysm developed. In two no complications occurred. The other complications that occurred were an enzymatically confirmed but small reinfarction, an angiographically confirmed but circumscript aneurysm, and an uncomplicated bypass operation in one patient each. These three patients had a small increase (between 0.05 and 0.1) in ejection fraction. Reproducibility of the method of measuring the ejection fraction was assessed concurrently in 20 outpatients with a previous myocardial infarction who were studied twice on the same day (with a 30 minute interval) by two different observers. The mean absolute difference in ejection fraction between the paired observations was 0.036 +/- 0.023 with a range of 0 to 0.07. Thus only changes in ejection fraction of more than 0.1 correlate with clinically recognised complications. Changes between 0.05 and 0.1 may be due to spontaneous variability or to the limited reproducibility of the method.

Effects of heart rate changes on left ventricular volume and ejection fraction: a 2-dimensional echocardiographic study

The influence of heart rate on left ventricular (LV) volumes and ejection fraction (EF) using 2-dimensional (2-D) echocardiography during atrial pacing was analyzed. The study was performed in 13 normal control subjects, 23 patients with coronary heart disease and 8 patients with dilated cardiomyopathy. An electronic sector scanner (2.25 MHz, 84 degrees) was used. Under constant scanning of the left ventricle, heart rate was increased, in steps of 20 beats/min, from 80 to 140 beats/min. The 2-D echocardiograms were stored on videotape and analyzed off-line. The end-diastolic and end-systolic volumes (EDV and ESV) were determined using a disc method. Stroke volume (SV) and EF were calculated. Constant LV scanning was possible during atrial stimulation, as shown by the analysis of simultaneously recorded 2-D echocardiograms and cineventriculograms at different heart rates, revealing a constant position of the echocardiographic transducer. Simultaneous recordings of cineventriculography and 2-D echocardiography at 80 and 120 beats/min showed that despite differences in absolute values, percent changes of LV volumes and EF determined with both methods were similar. Thus, changes of LV function can be analyzed by 2-D echocardiography. In normal control subjects, an increase in heart rate of 10 beats/min reduced EDV by 4 ml, ESV by 2 ml, SV by 2 ml and EF by 1%, corresponding to percent reductions of 4, 2, 5 and -2%, respectively. In contrast, the absolute decreases in the patients were 6 ml, 1 ml, 5 ml and 2% and the percent changes 2%, 1%, 8% and 5%.(ABSTRACT TRUNCATED AT 250 WORDS)

Echoventriculography -- a simultaneous analysis of two-dimensional echocardiography and cineventriculography

Two-dimensional echocardiography underestimates left ventricular volume compared with cineventriculography. To exclude the influence of difference in heart rate, blood pressure, respiration phases and any effect of the contrast material on left ventricular function, simultaneous studies of two-dimensional echocardiography and cineventriculography-echoventriculography were performed in 46 patients. Apical two-dimensional echocardiograms in the right anterior oblique (RAO) equivalent view were recorded before and during cineventriculography in the 30 degrees RAO projection. End-diastolic and end-systolic volumes (EDV and ESV) were calculated using a disc method with a semiautomatic computer system. The echo transducer position relative to the left ventricular apex and long axis was analyzed. For EDV determined by two-dimensional echocardiography and cineventriculography, the linear regression equation was y = 0.659x + 0.8, SEE = +/- 26.2 ml, r = 0.907. For ESV, the regression equation was y = 0.571x + 17.8, r = 0.938, SEE = +/- 18.6 ml, and for ejection fraction (EF) it was y = 0.606x + 13.0, r = 0.803, SEE = +/- 9.1%. Injection of contrast material resulted in only a small increase of stroke volume, caused by an increase of EDV as analyzed by echoventriculography. In all but two patients, the transducer position was found to be anterior and superior to the left ventricular anatomic apex, as evaluated by filming the echo transducer position during cineventriculography in 46 patients in the 30 degrees RAO projection and in 15 patients consecutively in the 60 degrees left anterior oblique and 30-40 degrees cranial projections. Thus, tangential cuts of the ventricle resulted in underestimation of diameters, long axis and ventricular volumes. These methodologic problems are exacerbated by slice-thickness artifacts. Furthermore, different outlining of left ventricular contour -- outer border of ventricular trabeculae for cine ventriculography and inner border for two-dimensional echocardiography -- seemed to result in underestimation of volume by echocardiography.

Contrast echocardiography

Contrast echocardiography is the technique of injecting an echo-producing, biologically compatible solution into the bloodstream and using M-mode and/or two-dimensional echocardiography to observe intracardiac bloodflow patterns revealed by the resulting cloud of echoes. This information was previously available only from angiocardiography. Contrast echocardiography has become a well-established adjunct to M-mode and two-dimensional echocardiographic examination and is valuable in the identification and validation of normal and abnormal cardiac structures, for the demonstration (and exclusion) of intracardiac as well as extracardiac shunts, and in the diagnosis of valvular regurgitation. In addition many clinical applications are being developed. Future research directions include development of videodensitometric techniques for contrast quantitation, finding contrast agents capable of passing the lung capillary bed and measurement of right heart pressures using microbubble resonance techniques.