Comparison of echocardiographic and necropsy measurements of left ventricular wall thickness in patients with coronary artery disease

The necropsy and echocardiographic (echo) measurements of left ventricular (LV) wall thickness differ from each other. To investigate the reasons for this disparity, the diastolic and systolic LV thicknesses were correlated by echo and necropsy measurements in 41 patients. The diastolic LV wall thickness (12.7 ± 2.8 mm) was significantly less than the systolic LV wall thickness by echo (16.7 ±3.1 mm; p < 0.001) and the necropsy LV wall thickness (15.9 ± 3.5 mm; p < 0.001). The systolic measurements of the LV wall thickness by echo correlated well and did not differ from the necropsy measurements of the LV wall thickness (difference not significant). Thus, disparities exist between the echo diastolic LV wall thickness and the necropsy LV wall thickness, as the hearts are in the systolic phase of the cardiac cycle. The echo systolic LV wall thickness measurements do not differ from the necropsy LV wall thickness measurements and the former are predictive of necropsy LV wall thickness.     

Enhanced detection of proximal right coronary artery stenosis with the additional analysis of right ventricular thallium-201 uptake in stress scintigrams

The value of right ventricular thallium-201 analysis in detecting proximal right coronary artery stenosis in exercise myocardial scintigraphy was analyzed in 52 patients, 27 with and 25 without proximal right coronary artery stenosis. For the detection of proximal right coronary artery stenosis, the sensitivity and specificity of thallium scintigraphic analysis were 59 and 88% for a right ventricular abnormality, 67 and 68% for a left ventricular inferior wall abnormality, and 93 and 56% for an abnormality of either. When both right and left ventricular thallium images were abnormal, all 9 patients had proximal right coronary artery stenoses, and when both were normal, 26 of 28 patients had a normal proximal right coronary artery. The sensitivity and specificity of blood pool scintigraphic variables during exercise (right ventricular ejection fraction and left ventricular inferior wall motion) were not significantly different for detection of proximal right coronary artery stenosis.Thus, the additional analysis of the right ventricle on thallium-201 stress scintigrams can improve the detection of proximal right coronary artery stenosis. When both right ventricular and left ventricular thallium scintigrams are abnormal (or normal), the ability to predict the presence (or absence) of proximal right coronary artery stenosis is very high.     

Two-dimensional echocardiographic assessment of right ventricular volume in children with congenital heart disease

The ability of 2-dimensional echocardiography to measure right ventricular (RV) volume and ejection fraction was assessed in 22 children with congenital heart disease. From the apical 4 chamber 2-dimensional echocardiographic image, the long-axis length of the right ventricle was measured and the area planimetered. On the anteroposterior and lateral cineangiocardiographic planes, the right ventricle was separated into 2 parts: RV sinus and outflow tract. The longest length, inflow tract length, and area of the sinus were measured from biplane cineangiographic views. The echographic long-axis length correlated well with the longest length of the RV sinus measured from both anteroposterior and lateral cineangiographic views at both end-systole and end-diastole. Moreover, the echographic area correlated well with the sinus area obtained from both cineangiographic views. From these regression analyses, the echographic long axis length and area were corrected to the angiographie longest length and area of the sinus. The new corrected echographic longest length and area were applied to 3 formulas (2 biplane and 1 uniplane) to calculate the sinus volume of the right ventricle. Total RV volume was then derived from the sinus volume. RV volumes and ejection fraction determined by 2-dimensional echocardiography were compared with those obtained from biplane cineangiography using Simpson's rule method. All formulas tested predicted RV volumes and ejection fraction with equal accuracy. Thus, 2-dimensional echocardiography can assess RV volume and ejection fraction in children with congenital heart disease.     

Derangements of myocardial metabolism preceding onset of ventricular fibrillation after coronary occlusion

To determine alterations in myocardial metabolism and and hemodynamics that occur within the first 30 minutes after coronary arterial occlusion, before the onset of ventricular fibrillation, measurements were compared in two series of dogs. Series A, 90 dogs that did not manifest ventricular fibrillation after coronary occlusion, were considered a control group. Series B consisted of 28 dogs that had ventricular fibrillation within 30 minutes after occlusion. All had similar comprehensive measurements completed preceding the onset of ventricular fibrillation. The animals in series B (subseuqnt fibrillation) had significantly higher heart rates before and after coronary occlusion. In this series cardiac metabolism of the occluded segment judged by transmyocardial lactate extraction, potassium balance, sodium/potassium ratio and blood pH because grossly more abnormal after coronary occlusion than in series A. In 5 animals whose measurements were obtained within 5 minutes of the onset of ventricular fibrillation, a sudden massive lactate production, potassium loss and increased acidosis of the occluded portion supervened minutes before the onset of the fatal arrhythmia. Animals with ventricular fibrillation had higher intracoronary S-T segment elevation that persisted until the onset of ventricular fibrillation. Measurements of abnormal hemodynamic function (left ventricular end-diastolic pressure, peak systolic pressure and first derivative of left ventricular pressure [DP/dt]) were not associated with an increased incidence of ventricular fibrillation. The study indicates that animals that manifest ventricular fibrillation within 30 minutes after coronary occlusion have higher preocclusion heart rates, a more severe metabolic disorder of the coronary occluded segment and more persistent intracoronary S-T segment elevation compared with animals that do not manifest ventricular fibrillation.     

Two dimensional echocardiographic characteristics of double outlet right ventricle.

The reliability was evaluated of two dimensional echocardiography in distinguishing double outlet right ventricle from other anomalies of the great arteries. Accordingly, a combined retrospective and prospective study was conducted in 13 children with double outlet right ventricle, 12 with tetralogy of Fallot, 13 with complete d-transposition of the great arteries, 5 with congenitally corrected I-transposition and 2 with truncus arteriosus. Echographic findings using a standard long axis view in all subjects with double outlet right ventricle included (1) inability to identify a great artery arising from the left ventricle, and (2) lack of continuity between the anterior mitral leaflet and any semilunar valve. In the short axis view constant findings were (1) simultaneous imaging of both great arteries in an anterior location with the ventricular septum identified posteriorly on sweeping into the left ventricle, and (2) lack of a clockwise wraparound of the aorta by the right ventricular outflow tract. Imaging revealed that the great arteries were side by side in seven patients d-malposed in three and l-malposed in two. A modified left precordial tomographic view demonstrated both great arteries arising from the right ventricle in four of nine patients not treated surgically. In four patients with surgically repaired double outlet right ventricle, the left ventricular outflow tract had a tunnel-like configuration in the long axis view. These findings were diagnostic of double outlet right ventricle in all patients and accurately differentiated the malformation from other anomalies of the great arteries.     

Comparative echocardiographic study of recovery of diastolic versus systolic function after brief periods of coronary occlusion: differential effects of intravenous nifedipine administered before and during occlusion

The effect of intravenous nifedipine (5 micrograms/kg) on the recovery of myocardial function after occlusion of the left anterior descending coronary artery was studied in 18 closed chest dogs. Using computer-aided analysis of two-dimensional echocardiograms, systolic and diastolic function of ischemic segments in low papillary left ventricular cross sections were characterized, respectively, as holosystolic fractional area change and early diastolic velocity of luminal area change. The time required for systolic function to return to preocclusion values after a 1 minute untreated control occlusion (n = 12) was 5 to 10 minutes, and after a 2 minute occlusion (n = 6) it was 20 to 30 minutes. When nifedipine was administered during the occlusion, recovery after a 2 minute occlusion was accelerated slightly to 10 to 15 minutes. Recovery times of early diastolic function were substantially longer, and nifedipine effects were more pronounced. After a 1 or 2 minute control coronary occlusion, 60 to 75 minutes or 90 to 105 minutes were needed to return early diastolic function to normal levels. Nifedipine administered during a 1 or 2 minute coronary occlusion improved these recovery times to 10 to 15 minutes. When the dogs were treated with intravenous nifedipine before coronary occlusion, recovery after 1 or 2 minutes of acute ischemia was apparent as early as 2 minutes after reperfusion. Thus, intravenous nifedipine accelerates the recovery of myocardial function after brief periods of ischemia, and when administered before coronary occlusion, it assures very prompt recovery of function.     

Increased right ventricular wall thickness on echocardiography in amyloid infiltrative cardiomyopathy

In six patients with clinically significant amyloid infiltrative cardiomyopathy, echocardiographic right ventricular anterior wall thickness was significantly increased (mean 7.5 ± 2.3 mm; range 5 to 10 mm). This finding in conjunction with the previously described abnormalities of the left ventricle (symmetric increase in wall thickness, diffuse hypokinesia, and small to normal left ventricular diastolic dimension) is consistent with the findings of a diffuse myocardial infiltrative process and should minimize confusion with constrictive pericarditis.     

Comparison of hemodynamic responses to nifedipine and nitroprusside in severe chronic congestive heart failure

The hemodynamic effects of 20 to 40 mg of oral nifedipine were compared with those of intravenous nitroprusside in 11 patients with severe chronic congestive heart failure (CHF). In each patient, both drugs were administered to produce similar reduction of systemic vascular resistance (SVR) (29 ± 13% with nifedipine and 29 ± 12% with nitroprusside, difference not significant [NS]). At this comparable decrease in systemic vascular resistance, significant differences in hemodynamic responses to both drugs were noted: Nifedipine caused a smaller increase in cardiac index (20 ± 20% vs 40 ± 24%, p < 0.02) and a larger decrease in mean blood pressure than nitroprusside (16 ± 9% vs 8 ± 10%, p < 0.05). In addition, nifedipine produced a smaller decrease in mean pulmonary artery wedge pressure (13 ± 24% vs 36 ± 21%, p < 0.001) and pulmonary vascular resistance than nitroprusside (6 ± 42% vs 26 ± 46%, NS. Mean right atrial pressure decreased with nitroprusside, from 10 ± 7 to 5 ± 3 mm Hg (p < 0.05), but not with nifedipine (10 ± 7 mm Hg before and after nifedipine administration, NS). Left ventricular stroke work index increased with nitroprusside (20 ± 8 to 27 ± 9 g-m/m², p < 0.05), but did not change with nifedipine (21 ± 9 vs 21 ± 10 g-m/m², NS). These data show that nifedipine has an arteriolar dilatatory action in patients with CHF. However, compared with nitroprusside, nifedipine had a significantly larger hypotensive effect and had a lesser effect on right and left ventricular filling pressure, cardiac output and left ventricular function.     

Echocardiographic diagnosis of a mobile, pedunculated tumor in the left ventricular cavity

A mobile left ventricular tumor was detected by echocardiography. The tracing showed a cluster of echoes in the left ventricular cavity corresponding to the location of the tumor as seen in angiograms. At surgery the tumor was attached to the interventricular septum by a thin fibrous stalk.     

Characterization of left ventricular mechanical function during arrhythmias with two dimensional echocardiography: I. premature ventricular contractions

Two dimensional echocardiography was applied experimentally in the closed chest dog to quantitate left ventricular function during and immediately after single premature ventricular contractions induced through threshold stimulation at the apex. Coupling intervals were varied over a range from 35 to 85 percent of the R-R interval during normal sinus rhythm (920 to 980 ms). The quality of tomographic echocardiographic images during premature as well as postextrasystolic beats was found to be satisfactory for quantitating short axis section areas at end-diastole and end-systole. A systolic fractional area change was computed from two dimensional echocardiographic measurements to characterize mid ventricular cardiac function, which correlated significantly with peak left ventricular pressure and maximal first derivative of left ventricular pressure (dP/dt). Marked shortening of coupling intervals reduced fractional shortening during premature systole and enhanced the degree of potentiation during the postextrasystolic beat. By contrast, premature beats with relatively long coupling intervals caused less reduction in contraction and only minor postextrasystolic potentiation.Systolic shortening of left ventricular length as well as transverse diameters were studied in a two dimensional echocardiographic long axis cross section. During long coupling intervals contraction was normal except for distinct regional systolic outward “bulging” in the apical region. In contrast, short coupling intervals were associated with a more significant generalized derangement of ventricular wall motion during systole. It is concluded that the two dimensional echocardiographic method can be used to portray and quantitate global as well as regional left ventricular function during disturbances of cardiac rhythm.     

Idiopathic paroxysmal ventricular tachycardia with a QRS pattern of right bundle branch block and left axis deviation: A unique clinical entity with specific properties

Eiectrophysiologic evaluation before and after the serial administration of verapamil, lidocaine, propranolol, and procainamide was undertaken in 4 young, asymptomatic patients with recurrent, sustained ventricular tachycardia (VT). No patient had obvious organic heart disease. The electrocardiogram during sinus rhythm showed S-T depression and T-wave inversion over the inferior and lateral precordial leads in 3 patients. QRS morphologic characteristics during episodes of VT showed a pattern of right bundle branch block and left axis deviation. In all 4 patients, VT could be both induced and terminated with electrical stimulation. Verapamil terminated VT and prevented the induction of sustained VT in 3 patients, and markedly slowed the rate of VT in 1 patient. Procainamide effectively prevented the induction of sustained VT in 2 patients, and although ineffective in preventing induction in 2 patients, it slowed the rate of tachycardia in both. Lidocaine and propranolol did not prevent the induction of VT in any patient. These findings suggest that slow-response tissues may be involved in the genesis of VT in these patients, and that VT in these patients may represent a unique clinical entity with distinct electrocardiographic, electrophysiologic, and electropharmacologic properties.     

ST elevations in leads V1 to V5 may be caused by right coronary artery occlusion and acute right ventricular infarction

In 5 of 69 patients (7%) undergoing intracoronary or intravenous streptokinase treatment, the ST-segment elevations in leads V₁ to V₅ were caused by occlusion of the right rather than the left anterior descending coronary artery and by myocardial infarction (MI) of the right ventricular (RV) wall rather than the anterior left ventricular (LV) wall or the ventricular septum. RV involvement was documented by technetium pyrophosphate uptake, hypokinesia, dilatation and depressed RV ejection fraction. The left anterior descending artery was patent and the anterior LV wall had normal thallium-201 uptake, no technetium uptake and normal wall motion. ST-segment elevation was highest in lead V₁ or V₂ and decreased toward lead V₅; in patients with anterior LV MI, the ST-segment elevations are usually lowest in lead V₁ and increase toward the V₅ lead. In contrast to anterior LV infarcts, the R waves in leads V₁ to V₅ did not decrease and Q waves did not evolve with progression of the MI.The ST-segment elevations in leads V₁ to V₅ in our patients were associated with small or absent ST-segment elevations in leads, II, III and aVF, suggesting that in other cases of RV infarction, the appearance of ST-segment elevations in leads V₁ to V₅ is blocked by the dominant electrical forces of the LV inferior MI. This suggestion was confirmed in a canine model. Recognition of the presence of RV infarction may be therapeutically important.     

Noninvasive measurement of the rest and exercise peak systolic pressure/end-systolic volume ratio: a sensitive two-dimensional echocardiographic indicator of left ventricular function

Thirty-five patients with previous myocardial infarction and 25 normal subjects underwent subcostal view two-dimensional echocardiography at rest and at peak up-right bicycle exercise. The purpose was to assess changes in left ventricular volume with maximal upright bicycle exercise and to compare the utility of the peak systolic pressure/end-systolic volume index ratio and ejection fraction as indicators of left ventricular function. With exercise, normal subjects had a decrease in end-systolic volume index (22 +/- 8 to 11 +/- 3 ml/m2) (p less than 0.001); the normal ejection fraction (59 +/- 9 to 72 +/- 8%, p less than 0.001) and the pressure/volume ratio (6 +/- 3 to 18 +/- 6, p less than 0.001) increased. In patients with prior myocardial infarction there was no change in end-systolic volume index, ejection fraction or pressure/volume ratio with exercise. Although at peak exercise significant differences between normal subjects and patients with prior infarction were demonstrated in end-systolic volume index (p less than 0.001), ejection fraction (p less than 0.001) and pressure/volume ratio (p less than 0.001), the pressure/volume ratio provided sharper delineation between the two groups than did ejection fraction. The exponential relation of the pressure/volume ratio and ejection fraction at peak exercise demonstrates that the pressure/volume ratio is more sensitive as an indicator of normal or borderline left ventricular function and that ejection fraction is more sensitive in quantifying the degree of left ventricular dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of left ventricular mechanical function during arrhythmias by two-dimensional echocardiography. II. Location of the site of onset of premature ventricular systoles

Two-dimensional echocardiography was applied experimentally in a closed chest dog model with intact pericardium to determine the location, magnitude and extent of contractile response during pacing from discrete ventricular sites. Midventricular short-axis tomographic images obtained during regular sinus rhythm and subsequent premature ventricular beats provided comparative measurements of global and segmental systolic changes of cross-sectional luminal areas and myocardial wall thickness. Computer-assisted standardized analysis of segmental systolic fractional area change and wall thickening was used to map left ventricular contraction during normal rhythm and premature beats of 70% coupling interval, induced alternately from anterior and lateral aspects of the mid-left ventricular short-axis cross-sectional plane. A characteristic pattern consisting of early systolic contraction and wall thickening was followed by paradoxical motion and wall thinning in late systole in segments corresponding to the region of direct electrical stimulation. Statistical analysis of segment by segment function indicated a maximal amount of premature beat contractile derangement at the site of the stimuli. Pacing from a right ventricular wall site in the midventricular plane caused a similar premature beat response at the anterior aspect of the interventricular septum. It is concluded that two-dimensional echographic analysis of segmental ventricular function can identify the location of electrical stimuli, and thus might noninvasively characterize regional patterns of contraction associated with ectopic foci during arrhythmias.     

Development and regression of increased ventricular mass

This report deals with increased cardiac mass in the light of the following variables: normal ventricular growth (embryo, fetus, neonate and child), the response to work loads (hemodynamic stress) and hypoxia, the cell responses of hyperplasia (increase in cell number), hypertrophy (increase in cell size) and the type of cell (muscle or connective tissue), the age or maturity of the myocardium at the time the hemodynamic or hypoxic stress is imposed, and the biochemistry, ultrastructure and functional morphology (modeling) of the ventricles in response to volume or pressure overload. The desirable physiologic adaptations to work loads are characterized, and the transition from physiologic to pathologic states is examined, comparing and contrasting increased ventricular mass in patients and in trained athletes. Regression of increased ventricular mass is then discussed, first at the cell level (hypertrophy/hyperplasia; muscle cell/connective tissue cell), then at the organ level. The requirements for maintaining or establishing normal ventricular function after removal of overload are reviewed, together with such variables as the type and duration of preoperative hemodynamic stress, the right versus the left ventricle and the relative rates of contractile protein synthesis and degradation.     

M mode and cross-sectional echocardiographic features of flail posterior mitral leaflets

Seventeen patients with accepted M mode echocardiographic criteria for flail mitral leaflet were studied. M mode echocardiograms revealed characteristic disordered mitral valve motion: (1) 16 (94 percent) had chaotic diastolic mitral motion; (2) 14 (82 percent) had systolic mitral flutter; (3) 14 (82 percent) had systolic left atrial echoes; and (4) 12 (71 percent) had systolic mitral valve prolapse. In 8 patients (47 percent) all four findings were present, with three findings present in 16 (35 percent) and two findings present in 13 (18 percent); none had fewer than two findings. Cross-sectional echocardiographic studies in 10 patients revealed a systolic whipping motion of the posterior mitral leaflet into the left atrium in all, abnormal systolic mitral coaptation in all and an abnormal mass of systolic left atrial echoes in 4. None of the first three M mode criteria were observed in 230 patients with uncomplicated “mid systolic click-late systolic murmur” syndrome; cross-sectional echocardiography in 30 of 230 patients revealed normal systolic mitral coaptation and no systolic whipping of the tip of the posterior mitral leaflet into the left atrium.     

Obstruction within the right ventricular body: two-dimensional echocardiographic features

Real-time 2-dimensional (2-D) echocardiograms were performed in 4 patients, all with considerable obstruction within the right ventricular (RV) body, in 3 patients due to muscle bundles and in 1 due to hypertrophic cardiomyopathy (HC). None had obstruction at the pulmonic valve level or immediately below. Echocardiographically, obstruction presented in 3 patients as localized bulging of the RV free wall in the subinfundibular region such that the RV cavity presented a typical "hourglass" appearance. Associated ventricular septal defect (VSD) was detected in 2 patients by echocardiography. In the fourth case, a patient with HC, RV obstruction was associated with a prominent bulge of the ventricular septum into the right ventricle. In 3 patients, the obstruction was convincingly demonstrated only in the subcostal RV inflow-apex-outflow plane, rather than in the standard echocardiographic planes. Pulse Doppler studies in 2 patients demonstrated disturbed RV flow. Obstruction within the RV body is a potentially serious condition which has been overlooked both at cardiac catheterization and at surgery. Demonstration of this lesion by 2-D echocardiography appears feasible and would greatly improve diagnostic accuracy.