Journal of cardiography最新文献

In 16 patients with angina pectoris who had no histories of myocardial infarction, myocardial segment shortening was studied during angina-free periods. Myocardial segment length in the anterior wall of the left ventricle was calculated by measuring the spatial length between two points identified as junctions of ramifying branches of the left coronary arteries using biplane coronary cineangiography. Segment shortening was classified according to the severity of coronary arterial stenosis. The patients were categorized according to the severity of coronary arterial stenosis: as 1) the 0% stenosis (normal); 2) the 50% stenosis group; and 3) the 75-90% stenosis group. Total segment shortening in the normal group was the same as that in the 50% stenosis group (10.4 +/- 2.5%). However, in the 75-90% stenosis group, segment shortening was reduced to 7.3 +/- 2.5%. Effective segment shortening during the ejection period was reduced (5.0 +/- 1.8%) in the 75-90% stenosis group, as compared with the normal group (8.4 +/- 2.4%) and the 50% stenosis group (7.2 +/- 3.6%). This study demonstrated that segment shortening was reduced at rest in patients with angina pectoris who had had no previous infarction. A possible mechanism of this reduced segment shortening during angina-free periods may be irreversible myocardial alteration from recurrent ischemic attacks.

Cardiac function is difficult to assess in patients with atrial fibrillation due to the widely fluctuating cycle lengths resulting in variable ventricular hemodynamics. With respect to ECG-gated blood pool scintigraphy, distortion of the time activity curve occurs due to a summation of irregular cycle lengths. Therefore, performing such a study has been regarded meaningless. To evaluate left ventricular function during atrial fibrillation using scintigraphic technique, a new processing algorithm was devised to make multiple gated images which are discriminated by the preceding R-R interval, and left ventricular filling and function curves were established. The left ventricular filling curve, obtained by plotting end-diastolic volume against the preceding R-R intervals demonstrated an impairment of blood filling in cases of mitral stenosis and constrictive pericarditis, which resolved after mitral commissurotomy in case of mitral stenosis. The left ventricular function curve, established by plotting stroke volume against end-diastolic volume, was analyzed according to indices such as "slope" and "position". Both of these indices were significantly reduced in relation to the severity of heart failure according to the NYHA's functional classification and cardiomegaly on chest radiography. On individual comparisons of underlying diseases, the indices decreased in the following order; lone atrial fibrillation, hyperthyroidism, aging, hypertension, mitral valve disease, ischemic heart disease, dilated cardiomyopathy and aortic regurgitation. The indices correlated closely with ejection fraction. In cases of mitral regurgitation, however, the function curves were situated to the right and above those of lone atrial fibrillation and decreased in slope despite the fairly well-maintained ejection fraction. After treatment with digitalis and/or diuretics, the function curves shifted to the left and upward. In conclusion, left ventricular filling and function curves based on a newly-devised algorithm of ECG-gated blood pool scintigraphy are of considerable clinical value in evaluating cardiac performance in patients with atrial fibrillation. They are widely applicable to the assessment of therapeutic and interventional effects.

The present study clarified the pathogenesis of disproportional hypertrophy in terms of disturbed coronary microcirculation. Twenty-eight patients with hypertrophic cardiomyopathy (HCM) who had normal coronary angiograms were categorized in four groups according to distributions of disproportional hypertrophy on left ventriculography and biventriculography: (1) Interventricular septal hypertrophy, (2) septal and apico-anterior wall hypertrophy, (3) apico-anterior hypertrophy, and (4) nonspecific hypertrophy of the entire wall. All 28 HCM patients and 10 normal volunteers were tested using exercise myocardial scintigraphy, and the circumferential profiles were processed by computer to relate the washout rate and disproportional hypertrophy. Comparison of the mean curves and mean segmental values of the circumferential profiles of the HCM groups with those of the control group showed that the mean initial uptake values of the HCM groups were to be relatively low in the apical segment and in the lower portion of the anteroseptal segment representing disproportional hypertrophy of these segments. The mean values were significantly elevated in the upper portion of the anteroseptal segment which was projected as the largest amount of the myocardium three-dimensionally. The mean washout rates in the HCM groups were significantly decreased in all segments, especially in those segments which reflected disproportional hypertrophy. This trend was also observed in the segments with increased initial uptakes. On comparing the segmental values of all groups, the segments with initial uptakes and/or washout rates with having the mean value minus 2SD of the control group were observed in the profiles of 12 of the 28 HCM patients. These all had decreased washout rates. In 25 of the total segments of the HCM patients, the initial uptakes and/or washout rates were below the normal limit; 21 of these segments had only decreased washout rates, and 16 of these 21 segments belonged to disproportionally hypertrophic wall. These results indicate that the decreased washout rate in the disproportionally hypertrophic wall is characteristic of HCM. It is suggested that the decreased washout rate with the decreased initial uptake is caused by disturbance of the coronary microcirculation. In addition, the decreased washout rate without a decreased initial uptake is caused not only by disturbance of coronary microcirculation, but by a metabolic disturbance of the myocardial cells as well. Furthermore, both disturbances are closely related to the pathogenesis of disproportional hypertrophy.

Forty mildly diabetic men, with a mean age of 49 +/- 9.7 years, and without clinical or exercise electrocardiographic evidence of ischemic cardiac disease, participated in a study consisting of exercise thallium-201 myocardial scintigraphy and exercise radionuclide ventriculography. 1. Among the 40 patients, 16 (40%) showed no filling defect (negative cases). Mild defects (mild cases) and moderate defects (moderate cases) were observed in 12 and 12 cases, respectively. 2. The percent washout ratio was decreased in none of the 16 negative cases, in three of the 12 mild cases, and in 11 of the 12 moderate cases. 3. There were no significant statistical differences in age, duration of diabetes, fasting blood sugar, HbA1c, serum cholesterol, smoking or blood pressure. Percent of ideal body weight was greater in moderate cases (121 +/- 15%) compared to negative or mild cases (103 +/- 9%, 108 +/- 9%) (p less than 0.01). 4. The percent fractional shortening was decreased in mild cases and in moderate cases (34.6 +/- 6.3%, 32.6 +/- 8.4%) compared to negative cases (41.7 +/- 4.9%) (p less than 0.01). Weissler's index (PEP/ET) was higher in moderate cases (0.42 +/- 0.09) compared to negative or mild cases (0.35 +/- 0.05, 0.36 +/- 0.06) (p less than 0.05). 5. Left ventricular wall motion was abnormal on echocardiography in none of the 16 negative cases, in three of the 12 mild cases and in seven of the moderate cases. The site of echocardiographically abnormal wall motion coincided with the defect area on myocardial scintigraphy in six cases, but not in four cases. 6. Radionuclide ventriculographic studies statistically showed no significant differences in ejection fraction (EF), 1/3EF, time to peak ejection (TPE), ejection time (ET), peak ejection rate (PER), 1/3 filling fraction (FF), 1/3 peak filling rate (PFR) and time to peak filling (TPF). The peak filling rate (PFR) at rest was significantly lower in mild cases (2.4 +/- 0.5 EDV/sec, p less than 0.025). Although the PFR at rest in moderate cases was lower than in negative cases (2.9 +/- 0.6 EDV/sec, 3.2 +/- 0.7 EDV/sec), no significant difference was shown between them. The rate of increase in cardiac output was significantly lower in moderate cases compared to mild cases and negative cases (59 +/- 28%, 96 +/- 49%, 97 +/- 31%, p less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)

Echocardiographically abnormal regional configuration of the left ventricle is one of the clues in detecting asynergy of the left ventricular wall. For the quantitative assessment, regional left ventricular configuration was expressed quantitatively using a new index, relative curvature. To obtain the end-systolic curvature, end-systolic echocardiograms were digitized and divided into eight segments. Then end-systolic curvature was determined as the reciprocal of the circumradius of a triangle determined by three consecutive dividing points. Relative curvature was defined as the product of end-systolic curvature multiplied by end-diastolic circumference. To assess the accuracy of quantitative analysis of regional left ventricular wall motion by relative curvature, short-axis images of the left ventricle at the level of the chordae tendineae were analyzed in 20 patients with myocardial infarction and 20 normal subjects by three different indices: segmental area change using a fixed reference system, segmental wall thickness change, and relative curvature. Groups of 10 patients with anteroseptal infarction, 10 patients with inferoposterior infarction, and 10 normal subjects could be differentiated from each other by these three indices. With the 95 per cent confidence intervals obtained from 10 other normal subjects, asynergic segments were detected objectively. By segmental area change, the sensitivity was 100 per cent and the specificity was 90 per cent on the anterior wall; the sensitivity was 90 per cent and the specificity was 95 per cent on the posterior wall. By segmental wall thickness change, the sensitivity was 70 per cent and the specificity was 75 per cent on the anterior wall; and those were 80 per cent and 90 per cent, respectively, on the posterior wall. By relative curvature, the sensitivity was 100 per cent and the specificity was 85 per cent on the anterior wall; and those were 90 per cent and 90 per cent, respectively, on the posterior wall. It was concluded that left ventricular regional contraction could be assessed quantitatively by relative curvature which quantitatively expresses regional left ventricular configuration. This index is independent of any reference systems, so it is expected to be used for quantitative analysis of regional wall motion, even though the cardiac motion within the thorax is not disregarded.

The pathophysiological significance of coronary collateral vessels remains controversial, despite previous intensive studies. We performed the multistage supine ergometer stress test for 26 patients with effort angina and collaterals. The changes in the collaterals were observed during each anginal attack by coronary angiography before and after intravenous nitroglycerin. The collaterals of 21 patients disappeared or diminished during exercise-induced angina before nitroglycerin administration, and were unchanged in the remaining five cases. However, the collaterals of all patients after nitroglycerin administration were unchanged or increased during exercise-induced angina. Considering there were no significant changes in pulmonary arterial end-diastolic pressures during angina before and after nitroglycerin administration, a pressure gradient between the donor and recipient coronary arteries was suggested as being related to the patency of the collaterals. These results suggested the following: 1. It is not appropriate to postulate that the collaterals visualized at rest may remain unchanged during exercise-induced angina. 2. It is not reasonable to conclude that exercise accelerates the development of collateral circulation. 3. One favorable effect of nitroglycerin administration is the prevention of exercise-induced ischemia via collateral circulation.

Seventy patients with bioprosthetic mitral valve were examined to study the applicability of the Doppler techniques including pulsed, continuous wave and color Doppler echocardiography in diagnosing and evaluating the severity of prosthetic valve dysfunction. The study population consisted of 70 patients who underwent mitral valve replacement (45 patients with Hancock valve, 13 with Angell-Shiley valve, 10 with Carpentier-Edwards valve). The dysfunctions were transvalvular regurgitation in 20 instances and paravalvular regurgitation in three, all of which were confirmed at surgery. A control group of 47 patients with the normally functioning porcine prosthetic mitral valve were also studied. Diastolic transmitral flow patterns were recorded from parasternal and apical approaches using color Doppler echocardiography, and the direction of the flow was definitely identified on the flow image. Transmitral flow signals spread from the mitral orifice to the mid-portion of the interventricular septum, and its direction was perpendicular toward the mitral ring in all cases. Flow velocity patterns in the left ventricle and atrium were recorded in the apical long-axis view of the left ventricle or apical four-chamber view using pulsed (high pulse repetition frequency) and continuous wave Doppler techniques. Two dynamic alterations in patients with the porcine mitral valve were evaluated from 1) the peak velocity and pressure half time (PHT) of transmitral flow in early diastole, and 2) the regurgitant jet in the left atrium indicating transvalvular or paravalvular regurgitation. The results were as follows: 1. Normally functioning porcine mitral valves were characterized by peak velocities (PV) less than or equal to 1.82 (mean +/- SD 1.44 +/- 0.27) m/sec and PHT less than or equal to 180 (mean +/- SD: 135 +/- 30) msec. In 23 patients with prosthetic valve dysfunction documented at surgery, peak velocity (mean +/- SD 2.23 +/- 0.19 m/sec) was significantly greater (p less than .001) than that of patients in the normally functioning prosthetic valves, and PHT ranged from 135 to 340 msec (mean +/- SD: 226 +/- 81 msec). 2. Among the 23 patients with porcine valve dysfunction, a harmonic striped pattern were recorded at the mitral valve levels in eight patients. All these patients had a musical murmur, and their peak velocity was more than 2.0 m/sec, but the PHT was less than 180 msec in seven patients. In these patients, valvular tears without calcification were confirmed at surgery.(ABSTRACT TRUNCATED AT 400 WORDS)

The occurrence of a systolic sound in hypertrophic obstructive cardiomyopathy (HOCM) has been well known for more than 20 years. This was phonoechocardiographically regarded as the sound coincident with the abrupt halt of the systolic anterior movement (SAM) of the mitral valve echo, and it has been termed the SAM sound. A 58-year-old man with HOCM was admitted with right hemiplegia. He was found to have a SAM sound which waxed and waned in intensity, and at times moved earlier into systole. He was studied by cardiac catheterization, M-mode and two-dimensional Doppler echocardiography (pulsed, continuous wave and color flow Doppler methods). Asymmetric septal hypertrophy (interventricular septal thickness = 25 mm, left ventricular posterior wall thickness = 14 mm), as well as SAM and midsystolic aortic valve closure were demonstrated. The presence and intensity of the sound was not related to rhythm (normal sinus rhythm vs atrial flutter), heart rate, respiration, position, or inhalation of amyl nitrite. Two-dimensional Doppler echocardiography revealed the following: 1. In the left ventricular outflow tract just below the aortic valve, a systolic turbulent flow was always present. 2. In the left ventricular chamber near the apex, a systolic laminar flow was interrupted in those cycles where the SAM sound was present. Otherwise, in cycles lacking the SAM sound, laminar flow in this locality continued throughout systole (even shorter duration than normal). 3. In the left ventricular inflow tract, diastolic flow was unaffected by the presence of the sound. 4. No mitral regurgitation was observed using color flow Doppler echocardiography. In summary, a SAM sound appeared to be associated with sudden deceleration of blood flow from the apex to the mid left ventricle.

Functional images of left ventricular myocardial perfusion were obtained using the washout time constant obtained from the analysis of digital subtraction angiograms (DSA). The results were compared with those of left ventriculography to evaluate its clinical validity. DSA examinations were performed in eight patients with old anterior myocardial infarction and in 10 control subjects. Washout time constant images of the left ventricular wall were nearly homogeneous in normal cases. On the contrary, regional heterogeneity on the washout time constant images was observed in cases of anterior infarction. The abnormal region in the washout time constant image corresponded well to the area of abnormal percent wall thickening, whereas the extent of the abnormal wall motion area tended to be broader than that of the abnormal washout time constant area or area of abnormal percent wall thickening. Thus, the washout time constant images obtained by DSA may comprise a reliable means of estimating the extent of ischemia in the myocardium.

Two-dimensional (2D) echocardiographic and clinical characteristics of patients with mitral regurgitation (MR) due to abnormal reinsertion of chordae tendineae (looping) in the middle scallop of the posterior leaflet were described and compared with those of patients with chordal rupture of the posterior leaflet. Twenty-five patients with posterior mitral valve prolapse who underwent mitral valve replacement were studied. They were categorized in three groups; 14 patients with MR due to ruptured chordae tendineae (RCT) of the posterior leaflet (RCT group); three patients with looping of the chordae tendineae in the middle scallop of the posterior leaflet (looping group); and eight patients with both RCT and looping (looping + RCT group). It was difficult to distinguish the looping group from the other two groups by their 2D echocardiographic findings, which were characteristic of those of RCT. However, the following findings were more frequently encountered in the patients with looping than in those without: 1) aberrant or absent systolic coaptation with salient arc of the posterior leaflet, observed in six of the RCT group (43%), two in the looping group (67%) and seven in the looping + RCT group (88%); 2) with thickened edges of the posterior leaflet, shown in three of the RCT group (21%), two of the looping group (67%) and five of the looping + RCT group (63%) in the long-axis view, and also noticed in four of the RCT group (29%), two of the looping group (67%) and six of the looping + RCT group (75%) in the short-axis view. In the clinical history, the onset of a heart murmur, congestive heart failure and surgical treatment occurred at significantly younger ages in the looping group than in the RCT group. As for hemodynamic parameters, pulmonary hypertension was significantly milder in the looping group than in the RCT group. In conclusion, although 2D echocardiographic findings of patients with looping were similar to those of patients with RCT, it seemed possible to differentiate the looping group from the RCT group by the 2D finding of a prolapsed posterior mitral valve with a salient arc and a thickened edge. It was also suggested that the looping of chordae tendineae in the middle scallop of the posterior leaflet was congenital in origin.