Journal of cardiography最新文献

Two-dimensional echocardiography (2DE) was performed in nine dogs with three hour proximal occlusion of the left anterior descending coronary artery and seven day reperfusion for sequentially mapping systolic functions (Seg-FAC%: percent segmental fractional area change) and diastolic functions (Seg-VLAC: mean velocity of segmental luminal area change) of eight segments in a mid-papillary left ventricular short-axis cross-section. The corresponding segment functions on 2DE to the most profoundly affected segment were evaluated by triphenyl-tetrazolium-chloride staining seven days post reperfusion, and categorized in two groups in terms percent mural necrosis (N%): N% greater than or equal to 40% in group A and N% less than 40% in group B, respectively. Seg-FAC% showed a significant difference between the two groups seven days post reperfusion (13.4 +/- 9.4% in group A, 53.3 +/- 7.7% in group B), while Seg-VLAC showed significant differences in the groups at three hours post occlusion (-1.6 +/- 2.1 cm2/sec in group A and 3.2 +/- 2.6 cm2/sec in group B) and seven days post reperfusion (0.48 +/- 4.7 cm2/sec in group A and 7.5 +/- 2.4 cm2/sec in group B). At seven days post reperfusion, Seg-VLAC correlated negatively with N% (r = -0.94), while Seg-FAC% did not with N% (r = -0.58). It was concluded that Seg-VLAC, after three hours' occlusion, predicts the recovery of the regional left ventricular function seven days after reperfusion; and Seg-VLAC, seven days after reperfusion can estimate the regional transmurality of necrosis thereafter.

The relationship between mitral inflow velocity patterns and left ventricular end-diastolic pressure (LVEDP) was evaluated using pulsed Doppler echocardiography in 34 cases of heart disease, without significant valvular regurgitation. Flow patterns in 19 of the 34 cases were also examined before and after the elevation of LVEDP by methoxamine infusion, 0.01 mg/kg/min. The ratio of the peak velocities in the atrial contraction phase to that in the rapid filling phase (A/R) and the ratio of mean acceleration rates to peak velocities in the rapid filling phase (ACR/R) were determined from the mitral flow patterns obtained by the apical approach. 1. ACR/R correlated significantly with LVEDP (r = 0.49), but A/R did not. LVEDP in six cases with normal A/R (0.5 to 1.0) was 8.3 +/- 2.9 mmHg (mean +/- SD). Among 19 cases with A/R of 1.0 or more and ACR/R less than 13 sec-1, LVEDP showed 10.2 +/- 3.8 mmHg. In eight cases with A/R of 1.0 or more and ACR/R of 13 sec-1 or more, LVEDP was 17.9 +/- 6.2 mmHg. The average value of LVEDP in two cases with A/R less than 0.5 was 18.5 mmHg. 2. When the LVEDP was elevated after methoxamine infusion, A/R within normal range increased in five of six cases and decreased in the remaining case. A/R more than 1.0 decreased in 10 of 11 cases and ACR/R tended to increase with increasing LVEDP.(ABSTRACT TRUNCATED AT 250 WORDS)

Two-dimensional echocardiographic examinations were performed for 86 patients with the hypoplastic right heart syndrome (55 cases of tricuspid atresia, 9 of pure pulmonary stenosis and 22 of pure pulmonary atresia). Prolapse of the anterior mitral leaflet was detected in 14 patients (16.3%). Four of these 14 patients had mitral regurgitation. Among the patients with mitral valve prolapse, ruptured chordae tendineae of the mitral valve were detected in two, and elongation of the chordae in one. There were no significant relationships between the incidence of mitral valve prolapse and sex, age, type of tricuspid atresia, previous palliative surgery, or PaO2. However, one patient with pure pulmonary stenosis, who had had mitral valve prolapse without mitral regurgitation, developed mitral regurgitation several months after undergoing a Blalock-Taussig shunt operation. The mechanism responsible for mitral valve prolapse in the hypoplastic right heart syndrome is not clear. Multiple factors, such as long-standing left ventricular volume overload, hypoxic myocardial damage, and anatomical chordal abnormalities may cause mitral valve prolapse. The presence of a mitral valve abnormality has an important bearing on the natural history as well as the surgical procedure of choice. The need for careful echocardiographic examinations to detect mitral valve abnormalities in the hypoplastic right heart syndrome is thus underscored.

An interesting case of right and left coronary arteries-right atrial fistulas diagnosed by Doppler echocardiography was presented. A 59-year-old woman was referred for evaluation of her continuous murmur. A thrill was palpable at the left sternal border in the third intercostal space. The proximal portions of the dilated right and left coronary arteries and distal portions of the tortuous and converging fistulas of both coronary arteries were imaged by two-dimensional echocardiography. Bidirectional continuous turbulent Doppler signals were detected in the proximal portions of the dilated right and left coronary arteries, in the distal portions of the fistulas around the crux and in the right atrium. These findings facilitated our diagnosis of right and left coronary arteries-right atrial fistulas. The flow velocity at the ostium of the right coronary artery was highest and nearly the same as the flow velocity (about 2 m/s) obtained by continuous wave Doppler from the maximum point of the thrill. The maximum pressure difference was considered located at this portion. Selective coronary angiography confirmed the right coronary artery and left main trunk-left circumflex coronary artery to be large, elongated and tortuous. These fistulas were communicating with the right atrium. This case demonstrates the usefulness of Doppler echocardiography in the noninvasive diagnosis of coronary arteriovenous fistula.

As a new method for regional wall motion analysis, the tomographic functional images, including "coronal", "sagittal" and "four-chamber" sections, were produced by applying the fundamental Fourier analysis using gated cardiac pool emission computed tomography (POOL-SPECT). Segmental wall motion was qualitatively assessed from the functional images in 10 normal subjects and in 48 patients with myocardial infarction. The results were compared with those assessed by gated blood pool planar images (modified LAO 45), two-dimensional echocardiography (2DE) or contrast left ventriculography (LVG). The following results were obtained. 1. POOL-SPECT imaging could separate the ventricle in three dimensions from the neighboring cardiovascular system by avoiding the overlapping blood pool to make accurate recognition of regional wall motion. 2. The functional tomograms had greater clinical efficacy in the diagnosis of infarcted segments than did the conventional equilibrium method, with high sensitivity (93/99, 93.9%), specificity (128/141, 90.8%) and accuracy (221/240, 92.1%), especially in the apical and inferoposterior portions. 3. Tomographic functional imaging facilitated estimating segmental cardiac performance from spatial and temporal aspects. The amplitude image which expresses regional stroke volume was readily available to detect hypokinesis and akinesis. The phase image of the initial cardiac movement was very useful for diagnosing dyskinesis. 4. In comparing the qualitative analysis with 2DE or LVG, complete agreement was observed in 80% (128/160) and 85.1% (149/175) of segments, though POOL-SPECT imaging showed underestimations in 11% of the segments. In conclusion, POOL-SPECT can be performed repeatedly without potential risks and the tomographic functional images derived from application of Fourier analysis to POOL-SPECT images are very useful for qualitative and three-dimensional analysis of regional wall motion. Thus, this technique may be a promising procedure in clinical investigations, obviating the disadvantages of conventional methods.

The two-dimensional and pulsed Doppler echocardiographic features of a case of isolated quadricuspid aortic valve with aortic regurgitation are described. A 62-year-old woman was hospitalized for exertional palpitation and dyspnea. Her physical examination showed the typical findings of aortic regurgitation. Two-dimensional echocardiograms revealed the aortic valve to have four cusps of nearly equal size. The accessory cusp was situated between the right and left coronary cusps. By pulsed Doppler echocardiography, holodiastolic turbulent flow signals were observed in the left ventricle, and the aortic flow pattern showed holodiastolic reverse flow, indicating severe aortic regurgitation. These findings were confirmed by aortography and by surgery. The coronary arteries and pulmonary valve were normal. We attempted a classification of the anatomical variations of the previously reported 34 cases of isolated quadricuspid aortic valves, including our own. They were classified as one smaller (67%), four equal (18%), three smaller (6%), four unequal (6%) and two smaller (3%) types. Twenty of the 34 patients had aortic regurgitation. Bacterial endocarditis and congestive heart failure were the main causes of death.

To develop ultrasonic cardiac tissue characterization, serial changes in intensity of backscattered ultrasound from the normal and infarcted myocardium were studied in vitro, with frequency-domain analysis. As an index of backscattered signal intensity, quantitative integrated backscatter [(10 X log-S2/S1)] (dB), S1 and S2 = areas of power spectra of digitized (sample rate = 100 MHz, 8 bits) ultrasonic signals from a perfect reflector and good specimens) were calculated for 60 regions of the myocardium (N = 20, MI = 40) excised from 10 dogs 3 days, 1, 2, and 4 weeks after coronary artery ligation in 2, 3, 3, and 2 dogs, respectively. The myocardial specimens and a stainless steel reflector were mounted at the focal distance of a newly-developed wide-band transducer having a center frequency of 4.0 MHz, in a water bath filled with degassed physiological saline. Tissue concentrations of hydroxyproline (HP) were also established using a HPLC (Hitachi amino acid analyzer model 835). The results obtained were as follows: 1. No significant changes in the integrated backscatter of the normal myocardium were observed throughout the experimental period (3 days = -52.5 +/- 0.7, one week = -53.6 +/- 1.8, two weeks = -51.6 +/- 0.8, four weeks = -52.8 +/- 1.4 (dB) (mean +/- SE). 2. Integrated backscatter of the infarcted myocardium [3 days = -47.3 +/- 0.6, one week = -49.2 +/- 1.3, two weeks = -40.7 +/- 1.3, four weeks = -39.6 +/- 2.0 (dB)] was significantly increased compared with the integrated backscatter of the normal myocardium in the early stage of myocardial infarction, before tissue concentrations of hydroxyproline increased, as well as in the chronic stage of myocardial infarction. 3. Results of histological examinations suggest that minute changes in structure, such as interstitial edema or neovascular proliferations, may be the cause of an early increase in integrated backscatter. The results suggest that quantitative integrated backscatter is a sensitive parameter for detecting both early and old myocardial infarction by cardiac tissue characterization.

The detection of regional myocardial dysfunction due to acute ischemic event has been limited almost entirely to experimental animal models. In human subjects, it has been limited to the observations during spontaneously-occurring or exercise-induced ischemic events. Recently, percutaneous transluminal coronary angioplasty (PTCA) provides an opportunity to study such dysfunction as the result of repeated interruptions of coronary blood flow. Echocardiograms and electrocardiograms were simultaneously recorded immediately before, during, and after 21 episodes of complete interruptions of coronary blood flow by PTCA in 11 patients. No patient had asynergy of the left ventricle either by two-dimensional echocardiography (2DE) or angiography. All patients had isolated single coronary artery stenosis including the left anterior descending artery in nine, left circumflex artery in one and right coronary artery in one. Recordings of M-mode and 2DE were successfully obtained in 10 patients. After balloon inflation, regional asynergy in the distribution of the instrumented coronary artery appeared in all 10 patients. Hypokinesis developed 9 +/- 3 (means +/- SD) sec after balloon inflation and progressed rapidly to akinesis or dyskinesis. At the same time, decreased systolic thickening of the left ventricular wall appeared in some patients in relation to the development of regional asynergy. However, systolic thinning of the left ventricular wall was not noted in all. The regional asynergy preceded ischemic electrocardiographic changes and had no relation to chest pain. Left ventricular wall motion began to normalize 12 +/- 3 sec after balloon deflation. Thereafter, transient hyperkinesis of the left ventricle developed. The first ischemic electrocardiographic change was a negative U wave which appeared 13 +/- 7 sec after coronary occlusion and remained 3 to 4 sec. Tall T waves were recorded at 28 +/- 12 sec and significant ST elevations developed 31 +/- 11 sec, after balloon inflation. These electrocardiographic changes invariably occurred only after the onset of wall motion abnormalities. Normalization of T waves was recognized at 17 +/- 16 sec and ST segment deviation were no longer present at 18 +/- 10 sec, after reperfusion. These electrocardiographic changes also preceded normalization of regional myocardial dysfunction. In conclusion, left ventricular wall motion abnormalities after coronary occlusion invariably precede the electrocardiographic changes, and begin to normalize after reperfusion prior to the electrocardiographic recovery.

For noninvasive evaluation of coronary blood flow, 22 patients were examined with transesophageal Doppler color flow mapping within six hours after cardiovascular surgery. The anatomical structure of the left main coronary trunk (LMT) was observed by conventional two-dimensional echocardiography (2-DE) in 20 patients (91%), and color flow of the LMT was visualized in 18 of 21 patients (86%) (one patient had total occlusion). The blood flow in the LMT began in mid-systole, but the flow was observed mainly in diastole. The peak of the flow was observed mainly in late diastole and the range of the peak velocity was 35 to 163 cm/sec (average = 76.9 +/- 31.4 cm/sec). The proximal portion of the right coronary artery (RCA) was observed in 13 patients (59%), and its color flow was visualized in only two patients (9%). In two patients intra-aortic balloon pumping (IABP) assist was performed postoperatively, and the direct effect of the assist on the coronary blood flow was clearly observed by transesophageal Doppler color flow mapping. The peak blood flow velocity of the LMT increased by 32% during the assist. In conclusion, human coronary blood flow can be visualized and evaluated noninvasively using transesophageal Doppler color flow mapping. This technique can be used for future investigation of coronary circulation.

The stress-redistribution thallium-201 scintigraphy and thallium-201 washout method have limitations in their ability to detect individual coronary lesions in patients with multivessel coronary artery disease. The purpose of this study is to investigate the value of the quantitative planar method using the dynamics of thallium-201 redistribution after exercise. We observed the patterns of thallium clearance in the late stages (at 2 and 4 hrs) which are characteristic of decreased myocardial blood supply by the obstructed coronary arteries. In 20 subjects, quantitative thallium scintigrams (planar image and circumferential count profile) and blood samples for thallium concentration were obtained immediately, and 2 and 4 hrs after maximal treadmill exercise. Coronary angiography was performed in all subjects, and 16 patients had coronary artery disease (CAD) and four were normal. The rate of thallium clearance from the blood (TCB) was compared with the rate of thallium clearance from each segmental lesion of the myocardium (TCM) between the 2- and 4-hr images. The system adopted for assignment of myocardial regions to individual coronary arteries has been used as an approach to localization of anatomic disease. In the four patients with normal coronary arteries, TCM exceeded TCB in all regions of all images (specificity 100%). Fourteen of the 16 CAD patients had at least one region where TCM was less than TCB (sensitivity 88%). Ten of the 14 patients with multivessel CAD had multiple regions where TCM was less than TCB (sensitivity 71%). All of the six patients without multivessel CAD (four with normal coronary arteries and two with one vessel disease) did not have multiple regions where TCM was less than TCB (specificity 100%). Quantitative thallium scintigraphy showed sensitivities of 86%, 56% and 91% in the left anterior descending artery, the circumflex coronary artery and right coronary artery, respectively. These results showed that decreased TCM in the late stage is characteristic of myocardial regions where blood is supplied by the diseased coronary arteries. This finding may improve diagnostic sensitivity under the condition of multivessel coronary artery disease.