Use Of M-mode Echocardiography Research Articles

The Early Days of Two-Dimensional Echocardiography in Korea (1977-1981)

Today, echocardiography is an essential non-invasive diagnostic imaging tool used in clinics worldwide. However, the application of ultrasound to the heart began only about 70 years ago. In the early 1950s, Hertz and Edler described the use of ultrasound for myocardial walls and mitral valve diseases. Feigenbaum (1960s) expanded the clinical use of M-mode echocardiography. The advent of two-dimensional (2D) echocardiography (1970s), spectral Doppler (1970s), and color Doppler (1980s) established them for routine assessment of cardiac anatomy and hemodynamics. In Korea, the history of 2D echocardiography spans only 46 years, within living memory, and some early contributions are often overlooked. The initial 2D imaging using mechanical sector scanning was very different from the current electronic phased-array scanners. This review explores the historical status and actual images of the initial 2D echocardiography in Korea in 1977-1981.

What is Multimodality Cardiovascular Imaging and How Can It Be Delivered?

### Learning objectives Imaging plays an essential role in the diagnosis and management of multiple cardiovascular diseases. The origin of non-invasive cardiovascular imaging dates back to 1953, when Inge Edler...

The role of echocardiographic deformation imaging in hypertrophic myopathies

Echocardiography has a leading role in the routine assessment and diagnosis of hypertrophic ventricles. However, the use of M-mode echocardiography and measurement of global left ventricular function may be misleading. Traditionally, systolic function was thought to be preserved in patients with hypertrophic myopathies until the late stages of the disease, and hypertrophic myopathies were thought to affect the myocardium more diffusely than ischemic heart disease. Ultrasound deformation imaging, either by Doppler myocardial imaging or speckle tracking, provides more-sensitive detection of regional myocardial motion and deformation than standard echocardiography. Basic and clinical studies that apply these techniques have revealed early, often subclinical impairment in systolic function. This information allows the detection and treatment of myocardial dysfunction at an early stage, which is of high clinical importance. Physiological hypertrophic remodeling seen in athletes differs from pathological myocardial hypertrophy, which can be caused by compensatory reactive hypertrophy owing to pressure overload in patients with aortic stenosis or hypertension, as well as amyloidosis, Fabry disease or Friedreich ataxia. Each of the etiologies associated with hypertrophy demonstrate distinct regional changes in myocardial deformation, which allows identification of the underlying processes, and will improve the assessment and follow-up of patients with hypertrophic myopathies.

Abnormal aortic elastic properties in adults with congenital valvular aortic stenosis

Background Abnormalities of the aortic root are common in patients with a bicuspid aortic valve. Our aim was to investigate the elastic properties of the aortic root in patients with congenital aortic valvular stenosis (AS) in comparison with age- and gender-matched controls, and to investigate the influence of stenosis severity and aortic size on aortic root elasticity. Methods Thirty-two adults (mean age 30.4 ± 7.5 years, 22 men) with congenital AS without previous cardiovascular surgery were prospectively studied. Aortic root elasticity indices such as aortic stiffness index (ASI), aortic root distensibility (ARD), and aortic strain were calculated with the use of M-mode echocardiography. Results ASI was significantly higher in patients compared to controls, 8.5 ± 8.4 versus 4.0 ± 1.4, respectively ( P < 0.01). Other indices of aortic root elasticity were similar between patients and controls: ARD was 4.2 ± 3.6 versus 4.3 ± 1.9 × 10 − 6 cm 2/dynes, respectively, and aortic strain was 12.4 ± 9.6 versus 13.5 ± 5.0%, respectively ( P = NS for all). Correlations were found between aortic size and indices of aortic elasticity (i.e., aortic strain and ARD), denoting that an increased aortic dimension is associated with a stiffer aorta. Interestingly, no correlations were found between indices of severity of AS and aortic elasticity, suggesting that an abnormal aortic elasticity is independent of stenosis severity. Conclusions Congenital AS results in abnormal aortic elastic properties, independent of stenosis severity. Furthermore, there seems to be a relationship between aortic dimensions and aortic stiffness.

History of echocardiography and its future applications in medicine

This review concisely presents the chronology of events that shaped the development of echocardiography. The concept of "seeing" structures using "sound" dates back to the 1920s, when ultrasound produced by piezoelectric crystals was used to detect flaws in metals. In the early 1950s, Hertz and Edler described the use of ultrasound for assessing mitral-valve disease. Subsequently, Harvey Feigenbaum in the 1960s standardized the clinical use of M-mode echocardiography for quantitative assessment of left-ventricular dimensions. The advent of 2-dimensional echocardiography (1970s), pulsed Doppler (1970s), and color Doppler (1980s) introduced new methods for routine assessment of cardiac anatomy and hemodynamics at bedside. Flexible scopes and superior transducers further paved the way to the application of transesophageal echocardiography. Tissue Doppler and contrast echocardiography recently have emerged as important tools for evaluation of regional myocardial function and blood flow. Miniaturization and the ability to pack thousands of crystals in an electronic array have transformed the application of 3-dimensional echocardiography into a bedside tomographic tool. At the current pace of development, echocardiography will be able to provide complete assessment of the heart in terms of its anatomy, coronary flow, and physiology. Training people and making it available at every bedside may be the only remaining challenges.

Changes in aortic root function after valve replacement in patients with aortic stenosis

Background Aortic elastic properties are compromised in various states that induce functional and histological changes in the aortic wall. Aortic stenosis is frequent and often requires replacement of the stenotic valve. The purpose of this study was to examine the effect of aortic valve replacement on the aortic root function. Methods 31 patients, mean ± SD age 67.2 ± 9.1 years with severe aortic stenosis, who underwent aortic valve replacement with a bileaflet mechanical prosthesis, were studied. Aortic root function indices such as aortic cross-sectional compliance (CSC), aortic root distensibility (ARD), and aortic stiffness index (ASI) were calculated with the use of M-mode echocardiography in three sessions: one preoperatively (pre-op), one on day 7 postoperatively (early post-op), and one 6 months postoperatively (late post-op). Results Aortic root function deteriorated early post-op ( p < 0.001 for all) and returned towards pre-op levels late post-op ( p = NS for all). CSC changed from 2.84 ± 1.98 to 1.37 ± 0.92, and 2.30 ± 1.11 cm 2/mmHg, ARD from 2.21 ± 5.60 to 1.01 ± 0.67, and 1.79 ± 0.96 cm 2/dyne, and ASI from 9.72 ± 5.60 to 24.65 ± 19.10, and 11.51 ± 7.85, respectively. Correlations were found between early changes in some aortic root indices and the degree of aortic stenosis, denoting that aortic function deteriorated less in more severe cases of aortic stenosis. None of the late changes were related to aortic valve or left ventricular indices. Conclusions Aortic valve replacement with a mechanical valve results in a significant but transient impairment of aortic distensibility.

The use of M-mode echocardiography to identify the true lumen in aortic dissection

Aortic dissection is a tear in the intimal lining of the aorta, with subsequent flow of blood into a false lumen. Determining which lumen is the true lumen is often clinically important, particularly if involvement of the coronary arteries is suggested. The use of M-mode imaging on echocardiography is often underused in the diagnosis of aortic dissection 1 and determining the true lumen in aortic dissection. 2 In the vast majority of cases, the pressure and velocity in the true lumen is greater than that in the false lumen in early systole. 3 In early systole, the pressure in the true lumen increases, expanding the true lumen while compressing the false lumen. This is described as pulsating oscillations or fluttering of the intimal flap. 4 On M-mode this is easily seen as expansion of the true lumen immediately after the QRS

M-mode echocardiographic evaluation of fetal and infant hearts: Longitudinal follow-up study from intrauterine life to year one

OBJECTIVE: Our purpose was to evaluate cardiac variables, including right and left end-diastolic and end-systolic dimensions by use of M-mode echocardiography during fetal, neonatal (transitional), and infancy periods to understand hemodynamic adaptation during these periods. STUDY DESIGN: Fifty-three fetuses were enrolled in this study. Echocardiography evaluations were started as early as the sixteenth week of gestation and were repeated every 4 to 6 weeks until term, on postnatal days 1 and 2, and at 6 weeks, 6 months, and 12 months of age. End-diastolic and end-systolic measurements were made according to published standards. Mean and SEM for each of the end-diastolic and end-systolic measurements were calculated for each of 11 study periods. Data were analyzed by one-way analysis of variance, corrected for repeated measures, and in the case of right and left ventricular differences paired t tests were used for significance. RESULTS: Left ventricular end-diastolic and end-systolic correlated positively with advancing age (R2 = 0.93, p < 0.0001), right ventricular end-diastolic also correlated with advancing age (R2 = 0.361, p < 0.05), and right ventricular end-diastolic was significantly larger than left ventricular end-diastolic in utero (p < 0.01), whereas the opposite was true after birth (p < 0.0001). Heart rate significantly decreased with advancing age (p < 0.001), whereas ejection fraction for either the right or the left ventricle did not change significantly with advancing age. CONCLUSION: This suggests that under basal conditions the ventricles can meet the increased demands in cardiac output by increasing ventricular dimensions without having to increase contractility reserve. (Am J Obstet Gynecol 1996;175:922-8.)

Measuring left ventricular function after heart transplantation via digitization of M-mode echocardiograms.

The aim of the study was to assess the usefulness of M-mode echocardiography for noninvasive diagnosis of cardiac rejection. For this purpose, 292 M-mode images of 26 heart transplant recipients were analyzed. The echocardiographic images were digitized into an image analysis system. The curves of left ventricular diameter changes were obtained and its first differential calculated. A total of 23 parameters were measured. The most important parameters were: peak velocity of systolic diameter change, peak velocity of diastolic diameter change, time to peak velocity of systolic diameter change, time to peak velocity of diastolic diameter change (TPEAK-D), isovolumetric relaxation time (IVRT), rapid filling time (RFT), shortening fraction (SF), and mean velocity of circumferential fiber shortening (MVCF). The echocardiographic parameters were compared to biopsy results. In 18 patients, 23 biopsy-proven moderate rejections occurred. When rejection occurred, IVRT decreased 23% +/- 6% (P < 0.05), SF decreased 13% +/- 14% (P<0.05), MVCF decreased 18% +/- 18% (P<0.05), and TPEAK-D increased 27% +/- 27% (P<0.05). We concluded that the analysis of digitized M-mode images can identify heart transplant rejection.

Usefulness of M-Mode Echocardiography in the Diagnosis of Heart Failure

The utility of M-mode echocardiography in the diagnosis of heart failure (HF) was evaluated in a study of 70 patients with suspected HF (26 men and 44 women) and 63 control persons (26 men and 37 women), all aged 45-74 years. The patients were classified according to the certainty of HF diagnosis using the Boston criteria: 27 patients were defined as 'unlikely' to have HF, 19 as having 'possible' HF, and 24 as having 'definite' HF. In calculations of the sensitivities and specificities for echocardiographic variables in detecting 'definite' HF, the 95% confidence limits in the control group were used as cut-off point values. Sensitivities thus attained were 91% for mitral valve E point-septal separation (EPSS), 73% for left ventricular (LV) fractional shortening (FS), and 64% for peak rate of increase of LV diameter (PLR), respectively, and the specificities were 73, 88, and 78%, respectively. When EPSS, FS and PLR were all normal, the likelihood of 'definite' HF was as low as 7%. We conclude that M-mode echocardiography is actually a useful method in the diagnostic evaluation of patients with suspected HF, and it is more reliable in excluding than confirming the presence of HF.

Cardiovascular Changes in Early Phase of Pregnancy

To assess the magnitude and timing of cardiovascular changes in pregnancy, eight subjects were serially studied before conception and at 8, 16, and 24 weeks' gestation. With the use of M-mode echocardiography, cardiac output, ejection fraction, stroke volume, and end-diastolic volume were calculated from left ventricular dimensions with subjects in the left lateral position. Systemic vascular resistance was calculated with the use of cardiac output and simultaneously obtained measurements of arterial pressure. Cardiac output increased 1 L/min at 8 weeks' gestation, which represented >50% of the total change seen. Cardiac output increased primarily because of stroke volume rather than heart rate. By 8 weeks' gestation, systemic vascular resistance had fallen to 70% of its preconceptional value. Thus when subjects are studied before conception and during the early phase of pregnancy, the majority of the pregnancy-induced changes in these parameters occur during the embryonic period.

Cardiovascular changes in early phase of pregnancy

To assess the magnitude and timing of cardiovascular changes in pregnancy, eight subjects were serially studied before conception and at 8, 16, and 24 weeks' gestation. With the use of M-mode echocardiography, cardiac output, ejection fraction, stroke volume, and end-diastolic volume were calculated from left ventricular dimensions with subjects in the left lateral position. Systemic vascular resistance was calculated with the use of cardiac output and simultaneously obtained measurements of arterial pressure. Cardiac output increased 1 L/min at 8 weeks' gestation, which represented >50% of the total change seen. Cardiac output increased primarily because of stroke volume rather than heart rate. By 8 weeks' gestation, systemic vascular resistance had fallen to 70% of its preconceptional value. Thus when subjects are studied before conception and during the early phase of pregnancy, the majority of the pregnancy-induced changes in these parameters occur during the embryonic period.

Optimal choice of prognostic variables with an application to cardiac monitoring using M‐mode echocardiography

This paper provides a methodology for the optimal choice of a subset from a large number of interrelated diagnostic variables. We use predetermined abnormal ranges for each measurement and code subjects as abnormal or normal on this basis. We present a procedure to determine the smallest subset of measurements that identifies any subject abnormal on at least one measurement. We formulate and solve the problem using integer programming. We then apply this methodology to study the use of M-mode echocardiography to determine potentially cardiotoxic side effects of chemotherapy and compare its performance to several multivariate methods. Extensions and modifications are discussed.

Cardiovascular changes in early phase of pregnancy

To assess the magnitude and timing of cardiovascular changes in pregnancy, eight subjects were serially studied before conception and at 8, 16, and 24 weeks' gestation. With the use of M-mode echocardiography, cardiac output, ejection fraction, stroke volume, and end-diastolic volume were calculated from left ventricular dimensions with subjects in the left lateral position. Systemic vascular resistance was calculated with the use of cardiac output and simultaneously obtained measurements of arterial pressure. Cardiac output increased 1 L/min at 8 weeks' gestation, which represented greater than 50% of the total change seen. Cardiac output increased primarily because of stroke volume rather than heart rate. By 8 weeks' gestation, systemic vascular resistance had fallen to 70% of its preconceptional value. Thus when subjects are studied before conception and during the early phase of pregnancy, the majority of the pregnancy-induced changes in these parameters occur during the embryonic period.

Echocardiographic decision-making for replacement surgery in mitral valve prolapse.

The clinical usefulness of M-mode echocardiography for predicting severe mitral regurgitation (MR) requiring valve replacement was assessed in 16 men and 10 women with mitral valve prolapse (MVP) as sole primary cardiac disorder. From left ventricular (LV) angiography, MR was classified as none to moderate (8 cases, group A) or severe (18 cases, group B). At echocardiography, increased LV end-diastolic and end-systolic and left atrial (LA) dimensions, corrected for body-surface area, distinguished group B from group A, with the best validities for LA and LV end-diastolic values. The mean echocardiographic LV fractional shortening and ejection fraction (EF) and the angiographic EF were similar in both groups. Echocardiographic and angiocardiographic LV EF correlated poorly, the former usually overestimating the latter. LV end-diastolic and mean pulmonary capillary wedge pressures were highest in group B, and the latter correlated with echocardiographic LA size. Mitral valve replacement was subsequently performed on 15 of the 18 group B patients. M-mode echocardiography is a valuable adjuvant to clinical assessment of MVP for predicting MR severity and for time-planning of cardiac catheterization or mitral valve surgery.

Early and late global and regional left ventricular function after experimental transmural myocardial infarction: Relationships of regional wall motion, wall thickening, and global performance

Experimental myocardial infarction of the posterolateral wall of the left ventricle was produced in dogs by injecting 80 μm microspheres into the left circumflex coronary artery (1) to determine changes in regional myocardial function after infarction, (2) to examine how the changes in regional myocardial function relate to the changes in global left ventricular function, and (3) to examine the relationship between regional wall motion and wall thickening after myocardial infarction. Serial measurements of global ventricular and regional myocardial function were made in six dogs before and during 20 days after infarction, with the use of M-mode echocardiography and chronic Swan-Ganz catheter impiantation. One hour after infarction, stroke volume index had decreased 49% from baseline, percent fractional shortening had decreased 52%, lateral wall motion had decreased 80%, and lateral wall thickening had decreased 100%. By 6 days after infarction, stroke volume index had increased 41% from its low point, percent fractional shortening had increased 34%, and lateral wall motion had increased 100% toward but not to baseline. Lateral wall thickening did not return following infarction. Peak and end-systolic circumferential wall stresses and systemic arterial blood pressure remained stable. End-systolic diameter increased acutely (36%) after infarction and did not change during the 20-day time period, while end-diastolic diameter gradually increased, resulting in the increase in percent fractional shortening. In conclusion, after posterolateral wall infarction, wall motion can return without an improvement in regional myocardial function, presumably because the infarcted region stiffens, allowing it to be pulled inward. Global left ventricular performance improves because of left ventricular dilation and improved wall motion. Wall thickening appears to be a more specific measurement for assessing chronic changes in regional contractile function than wall motion.

Echographic application of the Gorlin formula for assessment of aortic stenosis: Correlation with cardiac catheterization in pediatric patients

We have investigated the use of M-mode echocardiography for the diagnosis of aortic valve stenosis by application of the Gorlin formula. The hemodynamic parameters which enter this formula are shown to derive wholly from noninvasive measurements. The predicted valve areas correspond with those derived by classical catheterization studies at a level of r = 0.89, SE = 0.11 cm 2 n = 10. These results suggest that the Gorlin formula for aortic stenosis may have application in a noninvasive context.

Echocardiographic aortic valve area formula for the estimation of obstruction in stenosis.

We have investigated the use of M-mode echocardiography for the quantification of aortic valve stenosis through the application of a hydraulic orifice equation using only noninvasively determined hemodynamic variables. The new equation is A = (2/5)SV/(t3/2 dP1/4HR), where A is the effective aortic valve area in cm2, SV is the stroke volume in ml, t is the systolic ejection period in seconds, dP is the echographically estimated aortic valve gradient and HR is the heart rate. The predicted valve areas correspond with those derived by conventional cardiac catheterization studies at a level of r = 0.84, SE = 0.14 cm2, N = 10. The results suggest that M-mode echocardiography may have application to the quantitative diagnosis of aortic stenosis.

The valve of the foramen ovale in interatrial right-to-left shunt: Echocardiographic cineangiocardiographic and hemodynamic observations

In postpartum persistent right-to-left shunt at the atrial level, the valve of the foramen ovale fails to close. As a thin valve-flap the septum primum is pushed to the left during the phases of right atrial pressure predominance and closes to the septum secundum, when left atrial pressure exceeds right atrial pressure. Thus, it performs a marked movement during the cardiac cycle, reflecting the interatrial pressure-flow dynamics. With use of M-mode echocardiography, this movement pattern was studied in 24 patients: 13 with cyanotic heart disease (age 2 days to 21 years) and 11 newborns with persistent transatrial right-to-left shunt due to noncardiac disease. Cardiac defects were confirmed by cardiac catheterization and cineangiocardiography. Interatrial right-to-left shunts were proved by M-mode and 2-dimensional contrast echocardiography. The comparison of the M-mode echocardiographic findings in our patient groups with normal atrial septal movement studied in 20 healthy infants and children revealed considerable differences. The characteristic movement of the valve of the foramen ovale also was compared with results obtained by cineangiography and 2-dimensional echocardiography. Analysis of interatrial blood pressure difference provided a pathophysiologic explanation of the septum primum movement in transatrial right-to-left shunt.

Diagnosis of ischemic right ventricular dysfunction by M-mode echocardiography.

The importance of right ventricular infarction depends upon the presence and severity of the resultant ischemic right ventricular dysfunction. The usefulness of M-mode echocardiography for the diagnosis of ischemic right ventricular dysfunction was investigated in 63 patients with acute myocardial infarction. Group A included 35 patients with ischemic right ventricular dysfunction, and Group B 28 patients without ischemic right ventricular dysfunction. The diagnosis of ischemic right ventricular dysfunction was made when the right atrial pressure was higher than 10 mm Hg and greater than, equal to or not more than 5 mm Hg less than pulmonary capillary pressure. Right ventricular diastolic dimension was greater in Group A than in Group B ( P <0.01). The upper 95% confidence limit of this parameter was found to be 18 mm/m2 in Group B. The right ventricular/left ventricular diastolic dimension ratio was greater in Group A than in Group B ( P <0.01). The upper limit of this ratio in Group B was 0.63. When either of these two criteria was present (right ventricular diastolic dimension ≥ 18 mm/m2 or right ventricular/left ventricular diastolic dimension≥0.63), the diagnosis of ischemic right ventricular dysfunction could be made in 19 of 35 patients (sensitivity 54.2%), with no false positives (specificity 100%). The interventricular septum was rapidly displaced upwards at the beginning of systole and downwards during diastole in eight patients from Group A, and in no patient from Group B. M-mode echocardiographic indices of right ventricular dilatation may be of value in the diagnosis of ischemic right ventricular dysfunction, but their sensitivity is low. The discrepancy between hemodynamic and M-mode echocardiographic parameters of ischemic right ventricular dysfunction may be attributed to impairment of right ventricular compliance, with a right ventricular diastole dimension/right atrial pressure ratio greater in Group B than in Group A ( P < 0.01).