Normal Left Ventricular Wall Motion Research Articles

The spectrum of left main coronary artery disease: Variables affecting patient selection, management, and death

A total of 178 patients having a diagnosis of left main coronary artery stenosis were divided into three groups as follows: surgical, Group I (n = 135 patients); operable medically treated, Group II (n = 21 patients); and inoperable, Group III (n = 22 patients). Groups 1 and 2 were comparable with regard to clinical profile, extent of anatomic coronary disease, and left ventricular function. Inoperable patients had a much higher incidence of prior myocardial infarction (especially anterior), more severe distal coronary disease, and markedly depressed left ventricular function. The hospital mortality rate for surgical patients was 4% (6/135). The late mortality rate, (median follow-up = 23.4 months) was 7% (9/135). For operable patients, the late mortality rate was 43% (9/21) at 28 months. In the inoperable group, the late death rate at 20 months was 59% (13/22). Actuarial survival at 24 months for the three groups was: 88%, 66%, and 42%, respectively. Of the nine patients who died in the operable group, two had less than 75% obstruction of the left main coronary artery and two had normal left ventricular wall motion. Although patients with higher grades of left main coronary artery stenosis and reduced left ventricular function are at greater risk, patients with less obstruction and good left ventricular function are also at risk and should have myocardial revascularization with some sense of urgency. The population of left main coronary artery stenosis is a heterogeneous one, and comparison of surgical versus medical therapy should exclude inoperable patients. The operative mortality rate has been greatly reduced in recent years (2% in the last 100 cases); this is attributed to careful monitoring in the critical prebypass period, aggressive pharmacologic treatment of increased preload, tachycardia, and hypertension, and improved aurgical technique, with emphasis on careful myocardial preservation. Adherence to these principles makes frequent use of the intra-aortic balloon either before or after revascularization unnecessary.

Quantitative left ventricular wall motion analysis: a comparison of area, chord and radial methods.

We were interested in divising a relatively simple quantitative technique that could be used on a routine clinical basis for wall motion analysis. Three quantitative methods of left ventricular (LV) regional analysis were compared in the 30 degrees right anterior oblique and 60 degrees left anterior oblique projection. The control group consisted of 17 patients with qualitatively normal LV wall motion; the abnormal group comprised 17 patients with at least one region of severe, qualitative wall motion abnormality. Normal regional values were determined for area, chord and radial methods by applying the techniques to the ventriculograms of the control group. Each technique was then applied to the abnormal group's ventriculograms to determine the percentage of qualitatively abnormal regions not detected by each method. The area method had the lowest failure rate (p less than 0.001) and the best separation of measured normal and abnormal regions' ejection changes (p less than 0.001), and best reflected symmetric uniform motion of the ventricular silhouette. We conclude that the area method, of the techniques examined, was best for the quantitative analysis of LV wall motion abnormalities.

Transient defects of resting thallium scans in patients with coronary artery disease.

Defects on resting thallium-201 (/sup 201/Tl) scans in patients who do not have evidence of acute myocardial ischemia have been thought to represent myocardial scar. Our study of 20 patients with stable but severe coronary artery disease (CAD) was undertaken to reexamine the significance of such defects. Images in each of two projections were divided into three zones, for a total of 120 zones in 20 patients. An initial defect was present in 43 zones in 15 patients, while five patients demonstrated totally normal studies. On later scans, 18 defects persisted while 25 filled in. Twelve of 18 persistent defects were associated with ECG evidence of infarction, compared with only six of 25 transient defects. Six of 12 persistent defects, compared with only one of 18 transient defects, were associated with akinesia/dyskinesia. In addition, 17 of 18 transient defects were associated with either normal left ventricular wall motion (12 defects) or hypokinesia (five defects). Finally, 23 of 25 transient defects, compared with only 41 of 77 normal zones, were associated with severe CAD. Thus, in resting patients with stable CAD: (1) serial imaging reveals that many initial defects fill in over time; (2) initial resting defects on Tl scans maymore » not indicate myocardial scar; and (3) transient defects are usually associated with severe CAD, but normal or only mildly abnormal left ventricular wall motion.« less

Quantitative left ventricular cineangiography in patients with chronic obstructive pulmonary disease

Using quantitative measurements from cineangiograms, left ventricular function was evaluated in 19 patients with disabling COPD, 10 without and nine with previous right-sided heart failure. None had clinical evidence of diseases known to affect left ventricular function. Severity of airway obstruction was similar in patients without and with prior right-sided heart failure, but hypoxemia and pulmonary hypertension were significantly more severe in the latter. Mean resting cardiac index, left ventricular filling pressure and end-diastolic volume were normal in both groups. In 16 patients (10 without and six with prior right-sided heart failure), left ventricular function was clearly normal, as indicated by normal left ventricular wall motion, ejection fraction and mean velocity of circumferential fiber shortening (V CF). The remaining three patients had abnormal left ventricular wall motion, ejection fraction and V CF; these abnormalities could probably be attributed to coronary artery disease in two of the three patients but could not be explained in the third. Abnormal left ventricular function could not be correlated with the severity of COPD, hypoxemia or pulmonary hypertension. Left ventricular wall thickness and mass were normal in all, except for minimal increases in one patient without and one with prior rightsided heart failure. There are no previous reports of quantitative left ventricular cineangiography in patients with COPD, but our results are similar to those reported recently by investigators who measured ejection indices by other methods. It is concluded that a majority of patients with COPD, with or without right-sided heart failure, have normal left ventricular function in the absence of other heart disease.

Cardiokymography: Quantitative analysis of regional ischemic left ventricular dysfunction

Regional anterior left ventricular function was analyzed with cardiokymography in 24 patients undergoing diagnostic cardiac catheterization for suspected coronary artery disease. The noninvaslve kymographic tracing was recorded simultaneously with left ventricular pressure and normalized for differences in amplification. In 10 patients with normal anterior wall motion on ventriculography, the cardiokymogram revealed uniform inward motion during ejection, comprising 88 ± 4 percent (mean ± standard error of the mean) of total amplitude. Little change in amplitude was observed during isovolumic relaxation (−3 ± 7 percent). The remaining 14 patients all had significant coronary artery disease affecting the anterior wall of the left ventricle. In seven patients, with anterior dyssynchrony or hypokinesia, or both, the cardiokymogram revealed a significant decrease in systolic inward motion to 57 ± 9 percent of total amplitude ( P < 0.002) and a significant increase in isovolumic relaxation amplitude to 35 ± 18 percent ( P < 0.02). In the other seven patients, with anterior aklnesla or dyskinesia, or both, the cardiokymogram exhibited outward rather than Inward motion during ejection (−40 ± 11 percent). These observations in man are similar to those made with directly Implanted length gauges or ultrasonic crystals in animals subjected to acute myocardial ischemia. The data suggest that cardiokymography is capable of providing a clinical nonlnvaslve analog tracing that corresponds to normal and ischemic left ventricular wall motion. The technique therefore appears applicable to the noninvasive detection and serial evaluation of regional Ischemic contraction abnormalities in man.

Serial measurements of left ventricular ejection fraction by radionuclide angiography early and late after myocardial infarction

The left ventricular ejection fraction was determined serially with radioisotope angiography in 63 patients with acute myocardial infarction. After the peripheral injection of a bolus of technetium-99m, precordial radioactivity was recorded with a gamma scintillation camera and the ejection fraction calculated from the high frequency left ventricular time-activity curve. Since this technique requires no assumptions with respect to left ventricular geometry, it is particularly useful in patients with segmental left ventricular dysfunction. Serial measurements during the first 5 days after hospital admission were made in 50 patients, 30 of whom were studied during the subsequent 2 to 39 months (mean 19.9 months). Late follow-up serial studies were also performed in an additional 13 patients who had only one measurement of the left ventricular ejection fraction during the early postinfarction period. Early after infarction, the left ventricular ejection fraction was normal (more than 0.52) in only 15 of the 63 patients, and averaged 0.52 ± 0.05 (standard deviation) in the 27 patients with an uncomplicated infarct. The ejection fraction was reduced in 24 patients with mild to moderate left ventricular failure (0.40 ± 0.05, P < 0.0001) and in the 12 patients with overt pulmonary edema (0.33 ± 0.07, P < 0.0001). In 35 patients the ejection fraction correlated with the mean pulmonary arterial wedge pressure ( r = 0.72). In 15 patients with normal left ventricular wall motion by heart motion videotracking, the ejection fraction was significantly higher (0.53 ± 0.08) than in the 26 patients with regional left ventricular dysfunction (0.41 ± 0.10, P < 0.0001). During the early postinfarction period, the left ventricular ejection fraction improved in 55 percent of patients and remained unchanged or decreased in 45 percent. A further increase in the ejection fraction was noted in 61 percent of patients during the late follow-up period. Patients with an initially low or decreasing ejection fraction had a significantly greater incidence of early mortality and left ventricular dysfunction ( P < 0.02) than those whose ejection fraction was normal or improved to normal early after infarction. These data indicate that the ejection fraction is a sensitive indicator of left ventricular function after acute myocardial infarction and that serial measurements are helpful in predicting early mortality and morbidity.

Technetium 99m stannous pyrophosphate myocardial imaging in patients with and without left ventricular aneurysm.

To further explore the usefulness of technetium 99m pyrophosphate (99mTc-PYP) myocardial imaging and test its validity in the diagnosis of acute myocardial infarction, 99mTc-PYP myocardial scintigrams were performed in 50 patients. Out of 28 patients with acute myocardial infarction, myocardial scintigrams demonstrated localized activity in the 15 patients with transmural, and diffuse activity in the 13 patients with subendocardial myocardial infarction. Twenty-two patients with significant coronary artery disease documented by coronary angiography but without acute myocardial infarction were also studied. Nine of ten patients with clinical evidence of left ventricular aneurysm from previous myocardial infarction and definite left ventricular dyskinesis had positive scintigrams with activity localized to the site of the wall motion abnormality. Two of five patients without definite aneurysm but with left ventricular akinesis also had localized uptake in the involved area of the left ventricle. Seven patients with normal left ventricular wall motion had negative scintigrams. These findings suggest caution in interpreting positive 99mTc-PYP scintigrams as being indicative of acute myocardial infarction when evidence of a left ventricular aneurysm is also present.

Left ventricular performance assessed by radionuclide angiocardiography and echocardiography in patients with previous myocardial infarction.

In 61 patients (77 studies) who had a transmural myocardial infarction, we compared the left ventricular ejection fraction by echocardiography with the ejection fraction determined by a computerized radioisotope technique that makes no assumptions regarding left ventricular geometry. In 31 studies of 26 patients with normal left ventricular wall motion by videotracking and normal left heart size, ejection fraction averaged 0.57 +/- 0.09 (SD) by ultrasound and 0.62 +/- 0.10 by the isotope method. Measurements of ejection fraction by both techniques correlated well (r = 0.86) and there was complete separation between patients with normal and reduced ejection fraction. In 46 studies of 35 patients in whom left ventricular wall motion abnormalities were recorded by videotracking, ejection fraction by the isotope method averaged 0.46 +/- 0.08, while average echo ejection fraction was 0.62 +/- 0.12. The correlation between the ultrasound and isotope methods in these 46 studies was poor (r = 0.33) and in 28 studies measurement of the ejection fraction by the two techniques was discordant. In 26 of the 27 studies where there was a reduced ejection fraction by the isotope method and a normal ejection fraction by echo, the dyssynergy involved the anterolateral left ventricular wall. These data indicate that echocardiographic measurements frequently overestimate left ventricular performance in patients with previous myocardial infarction associated with anterolateral wall motion disorders.

Effects of nitroglycerin on left ventricular wall motion in coronary artery disease.

The effects of sublingual nitroglycerin (GTN) on left ventricular wall motion (LVWM) were examined by angiographic assessment in eight patients with anginal chest pain. Five of seven patients having occlusive coronary artery disease showed segmental abnormalities in LVWM characterized by regional hypokinesis or akinesis at rest. These abnormalities were accentuated by tachycardia induced by atrial pacing and were associated with the development of anginal chest pain. Two patients with one vessel coronary artery disease had normal LVWM at rest, but developed abnormalities during the stress of tachypacing. Administration of GTN reversed the LVWM abnormalities in all patients despite continued tachypacing. One patient with atypical chest pain but normal coronary arteries had normal LVWM at rest, following tachypacing, and after GTN. It is concluded that angiographic evaluation of LVWM provides a useful measure of segmental myocardial ischemia in patients with suspected coronary artery disease, and permits objective assessment of effects of antianginal drugs in reversing myocardial ischemia.

The standard 12-lead scalar electrocardiogram, an assessment of left ventricular performance

The results of standard 12 lead scalar electrocardiograms were correlated with left ventricular performance as reflected in the determinations of left ventricular end diastolic pressure at rest, ejection fraction and in the qualitative evaluation of left ventricular systolic wall motion. The study group included 55 patients who had at least 50% obstruction of one or more of the three major coronary arteries. The cardiothoracic ratio and a coronary artery index, expressing the residual patency of the three major coronary arteries, were also determined for each patient. The results indicate that normal left ventricular systolic wall motion can only be expected when the electrocardiogram is normal or reveals only minor repolarization abnormalities. Such an electrocardiogram favors but does not guarantee normal wall motion. Corresponding areas of abnormal left ventricular wall motion were observed in all cases with electrocardiographic evidence of a transmural anterior wall infarction and in the great majority of cases with an inferior wall infarction. Electrocardiographic evidence of a single transmural myocardial infarction was associated with a mean ejection fraction of 52% which was 10% less than that observed with a normal electrocardiogram and with only repolarization abnormalities. The reduction in ejection fraction was most marked in those with transmural anterior wall infarctions and in those with multiple transmural infarctions. The left ventricular end diastolic pressure was similar in those patients with and without electrocardiographic evidence of a transmural myocardial infarction. However, the mean left ventricular end diastolic pressure was significantly lower in those with inferior wall infarctions (13 mmHg) than in those with anterior wall infarctions (18mm Hg.). The total coronary artery index was not significantly different in patients with and without electrocardiographic evidence of a transmural myocardial infarction.