Two dimensional echocardiographic diagnosis of aortic dissection

The usefulness of two dimensional echocardiography in establishing the diagnosis of aortic dissection was evaluated. Forty-two patients were referred for study; 15 had a dissection and 27 did not. Two dimensional echocardiography detected the intimal flap in 12 of 15 patients with a dissection, the three false negative studies were in patients with a localized dissection. There was one false positive study in the 27 patients who did not have a dissection.

Spasm of a saphenous vein bypass graft. A possible mechanism for occlusion of the venous graft

The phenomenon of spasm in a venous graft was documented by angiographic study of the graft. This phenomenon has not been reported previously, and, therefore, its frequency of occurrence is unknown. Spasm of a venous graft may prove to play a significant role in the early development of myocardial infarction, closure of the graft, or recurrence of angina after initially successful surgery for aortocoronary bypass when venous grafts remain patent.

Echocardiographic and phonocardiographic assessment of the St. Jude cardiac valve prosthesis

Forty-three consecutive patients with a St. Jude mitral, aortic, or combined prosthesis were studied by simultaneous phonocardiography and echocardiography. Twenty-eight patients had a mitral prosthesis, 20 an aortic prosthesis, and five had both. No opening click was recorded in any patient; however, a loud aortic or mitral closing click was recorded in all 43 patients. In patients with St. Jude mitral valve prosthesis, an echo-free space separated the two leaflets during diastole; seven of these also had a mid-diastolic closing and late diastolic reopening motion; two of the seven had an associated closing mid-diastolic click. A mid-diastolic rumble was recorded in six of 28 patients with St. Jude mitral valve prosthesis. In patients with a St. Jude aortic valve prosthesis, left atrium leaflet motion was recorded in 17 of 20 patients and was indistinguishable in appearance from echocardiograms obtained with various eccentric monocusp valves. In addition, we report one case of malfunction of a St. Jude mitral valve and one case of a paravalvular leak diagnosed by echophonocardiography. We concluded that the St. Jude cardiac prosthesis has variable normal phonocardiographic-echocardiographic patterns. Knowledge of these variable patterns is important in assessing patients with suspected malfunction of a St. Jude cardiac prosthesis.

Value of exercise thallium-201 imaging in patients with diagnostic and nondiagnostic exercise electrocardiograms

The role of exercise imaging with thallium-201 in the evaluation of patients suspected of having coronary artery disease was studied in 194 patients undergoing diagnostic coronary arteriography. Ninety-eight patients had 70 percent or more narrowing of one or more coronary vessels and 96 patients had either no or insignificant coronary artery disease. One hundren twenty-three of the 194 patients had conclusive treadmill exercise electrocardiograms (either positive or negative), and 71 had inconclusive exercise electrocardiograms. Fifty-four of the 98 patients with coronary artery disease were receiving propranolol at the time of testing. Forty-five (83 percent) of the 54 patients receiving propranolol and 33 (75 percent) of the 44 patients not receiving propranolol had abnormal exercise thallium images (difference not significant). In patients with conclusive exercise electrocardiograms the sensitivity of exercise imaging was not significantly different from that of exercise electrocardiograms (80 versus 74 percent), but the sensitivity of both tests combined (92 percent) was higher than that of either test alone (p less than 0.01). The specificity of exercise imaging (97 percent) electrocardiograms the sensitivity of exercise imaging was not significantly different from that of exercise electrocardiograms (80 versus 74 percent), but the sensitivity of both tests combined (92 percent) was higher than that of either test alone (p less than 0.01). The specificity of exercise imaging (97 percent) electrocardiograms the sensitivity of exercise imaging was not significantly different from that of exercise electrocardiograms (80 versus 74 percent), but the sensitivity of both tests combined (92 percent) was higher than that of either test alone (p less than 0.01). The specificity of exercise imaging (97 percent) was higher than that of exercise electrocardiograms (86 percent, p less than 0.02). The specificity of both tests combined was not significantly different from that of exercise electrocardiograms alone. The sensitivity (79 percent) and specificity (95 percent) of exercise imaging were not significantly different in patients with inconclusive exercise electrocardiograms when compared with those in patients whose exercise electrocardiograms were conclusive. These data indicate that exercise imaging is sensitive and specific in diagnosing coronary artery disease in the presence of diagnostic as well as nondiagnostic exercise electrocardiograms and that propranolol therapy does not affect the results.

Quantitative radionuclide angiography in assessment of hemodynamic changes during upright exercise: observations in normal subjects, patient with coronary artery disease and patients with aortic regurgitation

Quantitative radionuclide angiography (with the first pass technique and a computerized multicrystal camera) was used to evaluate hemodynamic changes in three subject groups during symptom-limited upright exercise. The 12 normal subjects had significant increases in heart rate, stroke volume, left ventricular ejection fraction and cardiac output during exercise; changes in end-diastolic and end-systolic volumes were not significant. In the 24 patients with coronary artery disease there were significant increases in heart rate and cardiac output during exercise, but insignificant changes in end-diastolic, end-systolic and stroke volumes and ejection fraction. The change in diastolic volume in these patients was determined by the extent of coronary artery disease, propranolol therapy, end point of exercise and presence of collateral vessels. Furthermore, patients with previous myocardial infarction had a lower ejection fraction and higher end-diastolic and end-systolic volumes during exercise than those without myocardial infarction. In the 12 patients with chronic aortic regurgitation of moderate to severe degree, there was a decrease in the end-diastolic volume during exercise. This response was distinctly different from that of the normal subjects or the patients with coronary artery disease. All three groups had a significant decrease in pulmonary transit time during exercise. It is concluded that changes in cardiac output in normal subjects during upright exercise are related to augmentation of stroke volume and tachycardia, whereas in patients with coronary artery disease they are related mainly to tachycardia. Left ventricular dilatation during exercise occurred in some normal subjects and in patients with coronary artery disease but was not a consistent finding. However, a decrease in left ventricular end-diastolic volume is common in patients with aortic regurgitation. Such a decrease may be explained by a reduction in the regurgitant volume per beat caused by shortening of the diastolic filling period or a decrease in systemic vascular resistance, or both.

Exercise thallium 201 scintigraphy in evaluating aortocoronary bypass surgery

Thirty patients with recurrent symptoms after aortocoronary bypass graft surgery underwent angiography as well as exercise thallium 201 imaging. Exercise imaging has been shown to be highly specific (100 percent in our study) in evaluating patients after bypass surgery. Patients with complete revascularization have normal thallium 201 images. Similarly, exercise-induced defects are seen only in the presence of incomplete revascularization. There are patients, however, with incomplete revascularization with normal exercise images, but these generally limited to the right coronary artery or the diagonal vessels or their grafts.

Two-dimensional echocardiographic identification of surgically correctable complications of acute myocardial infarction

The appearance of a new, loud systolic murmur in a patient with congestive heart failure after an acute myocardial infarction suggests a surgically correctable cause of the heart failure. Using two-dimensional echocardiography, we studied 14 patients who presented in this manner. Four patients had rupture of a papillary muscle with a flail mitral valve. All four had surgery; three survived. Five patients had fibrosis of the posteromedial papillary muscle. All five had surgery; three survived. Five patients had a ventricular septal defect. Three of the five had surgery; one survived. Two-dimensional echocardiography is useful in studying patients with a new systolic murmur and congestive heart failure after acute myocardial infarction to detect surgically correctable structural defects.

Use of exercise thallium scintigraphy to assess extent of ischaemic myocardium in patients with left anterior descending artery disease

Images

A simplified valve formula for the calculation of stenotic cardiac valve areas

We have simplified the Gorlin formula and have compared our measurements of the aortic or mitral valve area, using the original Gorlin formula and the simplified valve formula in 100 consecutive patients. The valve area was measured by the simplified formula as cardiac output (l/min) divided by the square root of pressure differences across the valve. In patients with aortic stenosis of varying severity there were excellent correlation between the original Gorlin formula and the simplified formula (r = 0.96, y = 0.99x + 0.01, SEE = +/- 0.10, p less than 0.001). The correlation was unchanged when the peak gradient was used instead of the mean gradient in the simplified formula. Excellent correlation was also seen in patients with mitral stenosis of varying severity (r = 0.94, y = 0.97x - 0.02, SEE = +/- 0.19; p less than 0.001). The simplicity of the formula makes it easy to memorize and use.

Coronary artery disease confined to secondary branches of the left coronary system

Among 3,000 patients studied by coronary arteriography during a 4-year period, 31 patients (1%) had coronary artery disease limited to a diagonal branch of the left anterior descending (15 patients), marginal branch of the left circumflex (10 patients), or to both branches (6 patients). Ten patients had 50-69% and twenty-one had greater than or equal to 70% diameter narrowing. The suitability for grafting was noted in 20 patients as judged by the caliber and distribution of the diseased branches. Collaterals were noted in seven patients. Disease was present in 28 men and 3 women (age range 38-70 years). At least one major coronary risk factor was present in 27 patients. Angina was noted in 27 patients; prior myocardial infarction was noted in 5 patients by history and in 4 by ECG. The left ventriculogram was normal in 22 patients and showed mild segmental asynergy in 9; ejection fraction was normal in all. Exercise ECGs were positive in 12 of 25 patients; exercise 201thallium scans were positive in 13. All patients responded to medical therapy. In conclusion, among the population of patients who undergo catheterization, coronary branch disease is rare. The clinical findings are indistinguishable from patients with major coronary disease. Prognosis remains benign and patients respond to medical therapy.

Exercise thallium 201 imaging. Clinical implications of normal exercise images

To determine whether normal exercise images can reduce the need for coronary arteriography, we analyzed our data on 102 patients with normal thallium 201 exercise images who underwent coronary arteriographic studies. Eight-two patients had normal or insignificant coronary artery disease; 20 patients had significant coronary artery disease. Eight patients had disease limited to one of the secondary branches of the left system; seven patients had disease limited to one of the major coronary arteries; two patients had disease involving the right coronary artery and a secondary branch; two patients had disease involving two secondary branches; and one patient had disease involving the three major vessels. Seven of the 20 patients had abnormal exercise ECGs, and the remaining 13 patients had normal or inconclusive exercise ECGs. Our findings indicate that significant coronary artery disease is rare in patients with normal exercise images, especially if patients with abnormal exercise ECGs are excluded. Thus, normal exercise images could possibly reduce the need for coronary arteriography, since in these patients coronary artery disease rarely requires bypass surgery.

Left ventricular end-diastolic pressure in evaluating left ventricular function

There are several factors that could affect the left ventricular end-diastolic pressure. These include heart rate, preload, afterload, pericardial or pleural pressure, diastolic properties of the ventricle, and the left ventricular inotropic state. Recognition of these factors appears important when considering the left ventricular end-diastolic pressure as an index of left ventricular function.

Assessment of left ventricular function in patients with isolated severe disease of the left anterior descending artery: clinical, electrocardiographic, hemodynamic, and angiographic correlations

The purpose of this study was to define the spectrum of left ventriculographic (LV) abnormalities in 60 patients with isolated Greater Than or Equal To 90% diameter narrowing of the left anterior descending artery (LAD). The patients were divided into three groups: Group I (26 patients) had normal left ventricular (LV) function with ejection fraction (EF) of Greater Than 60% and no akinetic-dyskinetic segment representing abnormal contracting segments (ACS) of the left ventricular wall; Group II (15 patients) had mild to moderate LV dysfunction with EF of 40-60% and an akinetic-dyskinetic segment of Less Than 30% of the end diastolic perimeter (0-30%; mean, 11.6%) and Group III (19 patients) had severe LV dysfunction with EF Less Than 40%, or an akinetic-dyskinetic segment of Greater Than or Equal To 30% (30-81%; mean, 41.5%) or both. The data obtained from the history, physical examination, electrocardiogram (ECG), chest x-ray studies, hemodynamic studies, left ventriculography, and coronary arteriography were entered and filed on a memory disc in an IBM 370-168 computer. Analysis of the results showed: 1) more severe LV dysfunction is associated with increased incidence of large hearts, gallops, decreased cardiac output, and occlusion of the LAD. 2) ECG evidence of infarction is also associated with higher incidence of the abnormalities of the indices of LV dysfunction. 3) LAD occlusion (versus stenosis) has a higher incidence of severe LV dysfunction and prior infarction. 4) The site of LAD disease did not predict the extent of left ventricular dysfunction. 5) Collaterals did not protect against severe LV dysfunction.

Asymptomatic myocardial ischemia

In the vast majority of patients, angina pectoris is the cornerstone on which the diagnosis and treatment of coronary heart disease are formulated. There is evidence to suggest that transient myocardial ischemia may occur without angina pectoris; such episodes are generally detected during ECG or hemodynamic monitoring. The exact incidence, pathophysiologic nature, and importance of asymptomatic myocardial ischemia is not well known and needs further study.

M mode and two dimensional echocardiography in mitral and aortic regurgitation: pre- and postoperative evaluation of volume overload of the left ventricle

Both M mode and two dimensional echocardiography are useful in determining the origin of mitral regurgitation. Two dimensional echocardiography appears to be superior to M mode echocardiography in the diagnosis of a flail leaflet, papillary muscle dysfunction and cleft mitral valve. It is possible to differentiate valvular causes from myocardial causes of regurgitation. Unfortunately, the severity of mitral regurgitation is difficult to quantify with either the M mode or the two dimensional technique. Echocardiography does allow differentiation of acute forms of mitral and aortic regurgitation from chronic volume overload of the left ventricle. Rupture of chordae tendineae is the most common cause of acute mitral regurgitation, and two dimensional echocardiography is 96 percent sensitive in its detection. Bacterial endocarditis, flail aortic valve and dissecting aneurysm as causes of acute aortic regurgitation can be detected with two dimensional echocardiography. Systolic left ventricular cavity dimension, percent fractional shortening and ejection fraction are important variables in predicting optimal time for surgery in patients with chronic aortic and mitral regurgitation. The noninvasive technique of echocardiography may be especially useful in decision making in the asymptomatic patient.

Two dimensional echocardiography in congenital heart disease

Two dimensional echocardiography has enhanced the ability of the clinician to define accurately intracardiac anatomy and great vessel relations. By visualizing relations of the great arteries and determining ventricular situs in the parasternal short axis planes and by assessing the relation of the great arteries to ventricles atrioventricular (A-V) valves and the interventricular septum in the parasternal and apical long axis view, complex congenital heart disorders can readily be differentiated. The subcostal approach allows accurate identification and localization of interatrial and interventricular septal defects. Utilizing the apical parasternal four chambered or subcostal four chambered view, complex malformations of the A-V valves such as complete endocardial cushion defect and Ebstein's anomaly can readily be appreciated. The suprasternal approach has allowed direct visualization of a coarcted aortic segment. The differentiation of left and right ventricular outflow obstruction is also possible. In some patients, it is possible to achieve an accurate diagnosis with two dimensional echocardiography alone. In others, two dimensional echocardiography provides accurate and detailed information with regard to spatial anatomy and valve morphology so that invasive studies can be performed more expeditiously, with less contrast agent and hence with greater safety. With regard to future developments, better resolution capability with newer instrumentation and combined two dimensional echocardiography with Doppler blood flowmeter studies may provide even greater diagnostic accuracy in the evaluation of patients with congenital heart disorders.

Two dimensional echocardiographic recognition of the descending thoracic aorta: value in differentiating pericardial from pleural effusions

The course of the descending thoracic aorta has recently been visualized with two dimensional echocardiography and its presence confirmed with contrast studies. In the parasternal short axis view, we used the location of the descending thoracic aorta to differentiate pericardial from pleural effusions in 40 patients. Sixteen patients, each with an isolated pericardial effusion, had an echo-free space between the descending thoracic aorta and left ventricular posterior wall. Nine patients, each with an isolated pleural effusion, had an echo-free space posterior to the descending aorta. Fifteen patients, each with both a pericardial and pleural effusion, had echo-free spaces both between the descending thoracic aorta and left ventricular posterior wall and also posterior to the descending thoracic aorta. With one exception, all patients had anatomic confirmation of these findings. Forty-one patients undergoing cardiac surgery served as controls and none had a posterior echo-free space in relation to the descending thoracic aorta. At operation, no pericardial or pleural effusion was evident. The location of the descending thoracic aorta on two dimensional echocardiography serves as a valuable landmark in localizing the pericardial-pleural interface, thereby differentiating pericardial from pleural effusions.

Merits of stress thallium-201 myocardial perfusion imaging in patients with inconclusive exercise electrocardiograms: correlation with coronary arteriograms

Stress thallium-201 myocardial perfusion images were obtained in 65 patients with an inconclusive exercise electrocardiogram. All 65 patients underwent coronary angiograpic studies. The exercise electrocardiogram was judged inconclusive in 35 patients (54 percent) because submaximal exercise had been performed and in 30 patients (46 percent) who manifested ST-T segment abnormalities at rest. Exercise thallium-201 myocardial perfusion images were abnormal in 20 patients and normal in 45. Nineteen (95 percent) of the 20 patients with abnormal exercise images had severe disease of one or more major coronary arteries. Thirty-seven (82 percent) of the 45 patients with normal exercise images had no significant coronary artery disease; the remaining 8 patients had coronary artery disease. Therefore, 19 of 27 patients with coronary artery disease had abnormal exercise images (sensitivity 70 percent), and 37 of 38 patients without coronary artery disease had normal exercise images (specificity 97 percent). Thallium-201 imaging predicted the correct diagnosis in 56 patients (86 percent). Thus, exercise myocardial imaging with thallium-201 appears to be a useful diagnostic aid in patients with an inconclusive exercise electrocardiogram.

Two-dimensional echocardiographic recognition of left ventricular pseudoaneurysm

Five consecutive patients with proved left ventricular pseudoaneurysm (PA) and 22 patients with true aneurysm (TA) were studied by two-dimensional echocardiography (2DE). In four of the five patients with PA, 2DE successfully displayed the PA. The unique 2DE characteristics of PA include: (1) a sharp discontinuity of the endocardial image at the site of the PA communication with the left ventricular cavity; (2) a saccular or globular contour of the PA chamber; and (3) the presence of a relatively narrow orifice in comparison with the diameter of the PA fundus. In addition, 2DE detected the presence of thrombotic material within the extraventricular chamber in three of four cases. By deriving the ratios of the end-systolic orifice to diameter measurements for the patients with PA (0.37 +/- 0.07) compared with TA (1.00 +/- 0.08), we found that 2DE reliably differentiated PA from TA (p < 0.001). We conclude that 2DE is a useful noninvasive method for revealing left ventricular PAs and for distinguishing PA from TA. Considering the high risk of spontaneous rupture associated with pseudoaneurysms, this noninvasive capability is of paramount clinical importance.

Unstable angina pectoris: therapeutic choices

Unstable angina by definition involves a progressive process that has the potential for becoming acutely emergent. The authors offer criteria for monitoring the severity of the process, for designing medical therapy, and for making critical decisions with respect to turning from medical management to surgical intervention, either on an elective or an emergency basis.