Yukisono Suzuki

Detection and evaluation of tricuspid regurgitation using a real-time, two-dimensional, color-coded, Doppler flow imaging system: Comparison with contrast two-dimensional echocardiography and right ventriculography

To detect and evaluate regurgitant flow in tricuspid regurgitation (TR) with a newly developed, realtime, 2-dimensional (2-D), color-coded, Doppler flow imaging system (Doppler 2-D echo), 27 patients (18 with suspected TR and 9 normal subjects) were examined and the findings were compared with those obtained using contrast 2-D echocardiography (contrast 2-D echo) and right ventriculography. In 16 of 18 patients with suspected TR, Doppler 2-D echo easily visualized the color-coded regurgitant flow in the right atrium and estimated the severity of TR from the distance of the visible TR jet. On the basis of the QRS synchronized appearance of contrast in the inferior vena cava by the subxiphoid approach or of the negative contrast effect above the tricuspid valve just after the contrast entered the right ventricle with its subsequent back-and-forth movements across the tricuspid valve, Doppler 2-D echo was more sensitive and specific in detecting TR (100% and 100%) than contrast 2-D echo (75% and 82% in the subxiphoid view, 56% and 100% in the 4-chamber view) when the fast Fourier transformation frequency analysis was used as the standard of TR, and it was more sensitive in detecting TR (85%) than contrast 2-D echo (69% in the subxiphoid approach, 46% in the 4-chamber view) when right ventriculography was used as the standard of TR. Additionally, the severity of TR as shown by Doppler 2-D echo correlated fairly well with that shown by right ventriculography. Thus, Doppler 2-D echo is clinically useful for detecting and evaluating TR.

Stress scintigraphy using single-photon emission computed tomography in the evaluation of coronary artery disease

Twenty-seven patients with angina pectoris, 24 with postmyocardial infarction angina and 7 with normal coronary arteries were examined by exercise thallium-201 emission computed tomography (SPECT) and planar scintigraphy. Exercise SPECT was compared with the reperfusion imaging obtained approximately 2 to 3 hours after exercise. The sensitivity and specificity of demonstrating involved coronary arteries by identifying the locations of myocardial perfusion defects were 96 and 87% for right coronary artery, 88 and 89% for left anterior descending artery (LAD) and 78 and 100% for left circumflex artery (LC). These figures are higher than those for planar scintigraphy (85 and 87% for right coronary artery, 73 and 89% for LAD and 39 and 100% for LC arteries). In patients with 3-vessel disease, sensitivity of SPECT (100, 88 and 75% for right coronary artery, LAD and LC, respectively) was higher than planar imaging (88, 63 and 31%, respectively), with a significant difference for LC (p less than 0.05). In 1, 2 and 0-vessel disease the sensitivity and specificity of the 2 techniques were comparable. Multivessel disease was more easily identified as multiple coronary involvement than planar imaging with a significant difference in 3-vessel disease (p less than 0.05). In conclusion, stress SPECT provides useful information for the identification of LC lesions in coronary heart disease, including 3-vessel involvement.

Effects of coronary artery reperfusion on relation between creatine kinase-MB release and infarct size estimated by myocardial emission tomography with thallium-201 in man.

The quantitative relations between serum creatine kinase-MB isoenzyme (CK-MB) release and the final infarct size estimated by myocardial emission computed tomography with thallium-201 was assessed in 37 patients with a first acute transmural myocardial infarction who underwent intracoronary thrombolysis using urokinase 4.6 +/- 1.9 hours after the onset of symptoms. Serial CK-MB determinations were used to calculate the accumulated release of CK-MB (sigma CK-MB). Myocardial emission tomography with thallium-201 was performed 4 weeks after the onset, and infarct volume was measured from reconstructed tomographic images by computerized planimetry. The results are presented for two groups of patients: 11 patients with unsuccessful thrombolysis (group A) and 26 patients with successful thrombolysis (group B). An excellent linear relation was found for group A (sigma CK-MB = 6.4 X infarct volume + 47.7, r = 0.91), whereas a different linear relation was observed for group B (sigma CK-MB = 10.5 X infarct volume + 89.1, r = 0.80). Moreover, serum CK-MB activity reached a peak at 21.1 +/- 2.2 hours after the onset in group A and reached an earlier peak at 12.5 +/- 2.9 hours in group B (p less than 0.001). These data suggest that acute coronary recanalization alters the kinetics of CK-MB release, resulting in greater CK-MB release into the serum for equivalent infarct volume estimated by myocardial emission tomography with thallium-201. Thus, serum CK-MB time-activity curves after acute myocardial infarction may be influenced considerably by acute reperfusion, which is an important factor that should be incorporated in the interpretation of enzymatic estimates of infarct size in human patients.

Detection of intracardiac shunt flow in atrial septal defect using a real-time two-dimensional color-coded doppler flow imaging system and comparison with contrast two-dimensional echocardiography

To evaluate the noninvasive detection of shunt flow using a newly developed real-time 2-dimensional color-coded Doppler flow imaging system (D-2DE), 20 patients were examined, including 10 with secundum atrial septal defect (ASD) and 10 control subjects. These results were compared with contrast 2-dimensional echocardiography (C-2DE). Doppler 2DE displayed the blood flow toward the transducer as red and the blood flow away from the transducer as blue in 8 shades, each shade adding green according to the degree of variance in Doppler frequency. In the patients with ASD, D-2DE clearly visualized left-to-right shunt flow in 7 of 10 patients. In 5 of these 7 patients, C-2DE showed a negative contrast effect in the same area of the right atrium. Thus, D-2DE increased the sensitivity over C-2DE for detecting left-to-right shunt flow (from 50% to 70%). However, the specificity was slightly less in D-2DE (90%) than C-2DE (100%). Doppler 2DE could not visualize right-to-left shunt flow in all patients with ASD, though C-2DE showed a positive contrast effect in the left-sided heart in 9 of 10 patients with ASD. Thus, D-2DE is clinically useful for detecting left-to-right shunt flow in patients with ASD.

Recognition of regional hypertrophy in hypertrophic cardiomyopathy using thallium-201 emission-computed tomography: Comparison with two-dimensional echocardiography☆

The configuration of the hypertrophied myocardium was evaluated by thallium-201 emission-computed tomography and 2-dimensional (2-D) sector scan in 10 patients with obstructive hypertrophic cardiomyopathy (HC), 10 with nonobstructive HC with giant negative T waves and 10 with concentric left ventricular (LV) hypertrophy. Thallium-201 myocardial imaging was reconstructed into multiple 12-mm-thick slices in 3 planes. The thickness ratio of the ventricular septum and the LV posterior wall in the short-axis plane and the ratio of the ventricular septum and the apical wall in the long-axis plane were analyzed. In the patients with obstructive HC the ventricular septal wall thickness index was increased, and the ratio of septal to posterior wall thickness index (1.45 +/- 0.23) was greater than that in the patients with nonobstructive HC with giant negative T waves or in those with concentric LV hypertrophy (1.03 +/- 0.20 and 0.98 +/- 0.11, respectively; p less than 0.01 for each). In the patients with nonobstructive HC with giant negative T waves, increased apical wall thickness with apical cavity obliteration was characteristic, and the ratio of ventricular septal to apical wall thickness index (0.66 +/- 0.14) was less than that in the patients with obstructive HC or in those with concentric LV hypertrophy (1.46 +/- 0.38 and 1.04 +/- 0.09, respectively; p less than 0.001 for each). In contrast, technically satisfactory 2-D sector scanning (83%) demonstrated various configurations of the hypertrophied ventricularseptum, but could not detect apical hypertrophy in 4 of the 10 patients with nonobstructive HC with giant negative T waves whose LV cineangiograms demonstrated apical hypertrophy. Thus, thallium-201 emission-computed tomography is useful in evaluating the characteristics of LV hypertrophy and assists 2-D sector scan, especially in patients with apical hypertrophy in HC.

Septal Q wave in exercise testing: Evaluation by single-photon emission computed tomography

Changes of septal Q waves in lead V5 by exercise were evaluated with single-photon emission computed tomography. Coronary artery disease was present in 66 patients, 48 of whom had left anterior descending coronary artery (LAD) involvement. Forty-one subjects had normal coronary arteries. All patients under investigation were classified into 3 groups: group A (18 patients)--regression of Q amplitude during exercise; group B (48 patients)--progression or no change of Q wave or a new Q wave during exercise; and group C (41 patients)--no Q waves at rest and during exercise. Perfusion defects of the septum were calculated 3-dimensionally and expressed as a percent of the total septum. Seventeen patients (94%) in group A showed septal perfusion defects by exercise and all of them had LAD stenosis. Forty-three patients (90%) in group B showed no septal perfusion defects, but the others with perfusion defects had LAD stenosis. In group C, 23 of 41 patients (56%) had an LAD lesion, of whom 91% showed septal perfusion defects; none of the remaining 18 patients without LAD stenosis showed perfusion defects. The area of septal perfusion defects during exercise was larger in group A (62 +/- 19%) and in group C (52 +/- 19%) than in group B (23 +/- 9%) (groups A vs B, p less than 0.001; groups C vs B, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of anomalous origin of left coronary artery from pulmonary artery by real-time Doppler color flow mapping in a 53-year-old asymptomatic female

The anomalous origin of the left coronary artery from the pulmonary artery in a 53-year-old asymptomatic female was diagnosed by the color Doppler technique. Doppler color flow mapping on a modified high parasternal short axis view clearly demonstrated the blood flow from the anomalous left coronary artery into the pulmonary trunk. Aortography confirmed this finding. The anatomical factors of marked right coronary artery preponderance and a hypoplastic circumflex artery were considered to contribute to the long survival of this patient. In asymptomatic adult patients with this anomaly, Doppler color flow mapping is a sensitive diagnostic method, and should be used first in adult patients suspected of having this anomaly.

Asynchronous filling in ischemic heart disease and hypertrophic cardiomyopathy

A multigated blood-pool study was performed to assess regional and global emptying and filling in 16 patients with hypertrophic cardiomyopathy (HCM), 43 patients with ischemic heart disease (IHD), and 14 controls. The regional volume curve was fitted using second-order harmonics in the Fourier series, while the global left-ventricular volume curve was fitted using third-order harmonics. As asynchronous indices, the standard deviations (SD) in distribution histograms of time to end-systole (TES), time to peak ejection (TPE), and time to peak filling (TPF) were obtained in the left ventricle. In patients with IHD, the TPF-SD was higher (14.4±11.3°) than the TES-SD (7.8±5.1°) and TPE-SD (8.1±5.9°), suggesting the presence of asynchronous filling. In patients with HCM, the TPF-SD was also higher (11.6±11.1°) than the TES-SD (3.5±2.4°) and TPE-SD (6.2±4.4°). The phase delay was localized in the anteroseptal or apical region in all 5 HCM patients with abnormal wall motion, while it corresponded with the region of abnormal wall motion in the patients with IHD. The TPF-SD was inversely correlated with the left-ventricular ejection fraction (r=-0.46), peak filling rate (r=-0.50), and the ratio of peak filling rate to peak ejection rate (r=-0.52), suggesting that asynchronous filling is related to global diastolic disturbance. We conclude that asynchronous filling is often present in patients with IHD and HCM, and that our technique can be used to obtain a quantitative assessment of regional asynchronous emptying and filling in these diseases.

Interventricular septal motion in acute myocardial infarction with proximal and distal left anterior descending coronary lesions

To evaluate the ability of echocardiography to detect and localize lesions of the proximal and distal left anterior descending (LAD) coronary arteries, the systolic excursion of the left side of the septum and the ratio of septal to posterior wall excursion (IVS/PW) were measured in 26 patients with acute myocardial infarction (AMI) and nine normal control subjects. The patients with proximal LAD lesions had septal wall excursions of less than 3 mm, whereas in those with distal LAD lesions septal wall excursions were more than 3 mm. All patients with proximal LAD lesions showed an IVS/PW ratio of less than 0.4, but in those with distal LAD lesions the ratio was 0.4 or greater. We conclude that reduced or absent interventricular septal motion in anterior AMI suggests an LAD lesion, and a septal excursion of less than 3 mm suggests involvement of the proximal LAD artery, whereas septal excursion of 3 mm or more indicates involvement of the distal LAD artery.