Journal of cardiography最新文献

The sensitivity and specificity of the two-dimensional (2D) echocardiographic criteria for diagnosing ruptured mitral chordae tendineae (RCT) were assessed in 52 cases with non-rheumatic mitral regurgitation undergoing mitral valve prostheses. At surgery, chordal rupture was confirmed in 38 cases (RCT group), but not in 14 cases (non-RCT group). Four presumptive and three definite findings for diagnosing mitral chordal rupture using 2D echo were evaluated. Mitral valve prolapse with incomplete coaptation of the mitral leaflets in the long-axis view was observed in 32 cases in the RCT group and in four cases in the non-RCT group (sensitivity 84%, specificity 80%). In the short-axis view at the level of the mitral orifice, delayed closure of the involved mitral leaflet was observed in four cases in the RCT group but in none of the non-RCT group (sensitivity 11%, specificity 100%), delayed protodiastolic opening of the involved leaflet in 15 cases of the RCT group and in one of the non-RCT group (sensitivity 39%, specificity 92%), and finally, increased excursion of the involved valve in 27 cases of the RCT group and in three cases of the non-RCT group (sensitivity 71%, specificity 79%). The following three echocardiographic findings were regarded as direct evidence of mitral chordal rupture: Fine echoes with abnormally rapid transverse and/or oblique motion around the mitral orifice in the short-axis view were observed in 13 cases of the RCT group (sensitivity 34%, specificity 100%); echoes with abnormal whip-like motion in the long-axis view in 10 cases (sensitivity 26%, specificity 100%).(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular diastolic function and systolic function were evaluated using a recently-developed computerized cardiac nuclear probe (CNP). We measured left ventricular ejection fraction (LVEF) and ejection rate (ER) as the systolic function, and peak filling rate (PFR) and time to peak filling rate (TPFR) as the diastolic function in 95 patients including 34 ischemics, 38 hypertensives, and 23 anthracyclin-treated after the intravenous injection of 5 to 20 mCi Tc99m-albumin. The reproducibility of the measurements was studied, and the measurements were correlated with conventional gamma-camera cardiac blood scintigraphic and echocardiographic measurements. Reproducibility of the measurements using the cardiac nuclear probe were excellent for each measurement, and the correlation coefficients were 0.96 for LVEF, 0.88 for ER, 0.91 for PFR, and 0.80 for TPFR, respectively. LVEF by CNP correlated well with that by the gamma-camera (r=0.82, p less than 0.001) and echocardiography (r=0.76, p less than 0.001). LVEF, ER and PFR in ischemic heart disease were all significantly less (p less than 0.05), and TPFR was significantly greater (p less than 0.05) than those in the other study groups. These results emphasized the high resolution temporal imaging capacity of CNP and suggested that left ventricular filling abnormalities evaluated by CNP would be useful for the identification of incipient cardiac dysfunction.

The clinical validity and some problems concerning pulsed Doppler echocardiography (PD) in non-invasive estimates of pressure difference (delta P) across a ventricular septal defect were studied. The maximum velocity (max V) of the left to right shunt flow in the right ventricle was converted to delta P using the simplified Bernoulli equation: delta P = 4V2. We also used the equation: delta P = 4(V2(2) - V1(2)) to estimate the delta P in cases who had left to right shunt flows of high velocity in the left ventricle. Simulatenous recordings of both left and right ventricular pressures and PD were obtained during cardiac catheterization of 11 cases. Accurate Doppler estimates of delta P only from the maximum velocity of the left to right shunt flow in the right ventricle were impossible in nine cases whose actual delta P's were large (more than 41 mmHg) and also in eight cases whose right ventricular systolic pressure was high (either equal to or higher than left ventricular systolic pressure). Besides these 17 cases, delta P estimated by PD using the simplified Bernoulli equation in 39 cases, with pansystolic left to right shunt flows in the right ventricle, correlated well with the actually measured delta P (Y = 0.99X + 2.77, r = 0.91, p less than 0.01). The difference in the maximal instantaneous pressure gradient and Doppler delta P was considered insignificant (between 0 and 7 mmHg, mean 4 mmHg). In nine cases, the left to right shunt flows of relatively high speed (0.63 approximately 2.00 m/sec, mean 1.31 m/sec) were observed also in the left ventricle, and calculated delta P using the simplified Bernoulli equation overestimated the actually measured delta P by 2 to 16 mmHg (Y = 1.52X + 4.88, r = 0.95, p less than 0.01). However, if the delta P is estimated by using the equation, delta P = 4(V2(2) - V1(2)), without ignoring the maximum speed in the left ventricle (V1), it correlates well with the actually measured delta P (Y = 1.07X + 0.76, r = 0.98, p less than 0.01). Thus, in cases with left to right shunt flows with high speeds in the left ventricle, the equation: delta P = 4(V2(2) - V1(2)) was more accurate in estimating the delta P by pulsed Doppler echocardiography.

Digital subtraction angiography with selective coronary injections of contrast media has enabled us to obtain clear images, not only of the artery, but of the capillary and venous phases of the myocardial perfusion. In the present study, densitometry was used to estimate regional myocardial perfusion dynamics in 10 control cases and 11 anterior myocardial infarction cases. The time density curve showed that contrast material increased rapidly in the arterial phase and appeared to be washed out monoexponentially in the venous phase. The time from the onset of contrast medium injection to the maximal density of the contrast medium (Tp), and the time constant obtained from the washout curve (Tc) were analyzed. In the control group, Tp in the apical region was slightly prolonged as compared with Tp in the anterobasal region, but the difference was not significant (5.2 +/- 0.5 vs 4.2 +/- 0.4 sec: mean +/- SEM). Tc did not definitely change in any portion of the myocardium (anterobasal 5.1 +/- 0.5, anterior 4.8 +/- 0.5, apex 4.6 +/- 0.5 sec, respectively). In anterior myocardial infarction, Tp in the marginal region was significantly prolonged compared to Tp in the control region (6.0 +/- 0.3 vs 4.7 +/- 0.3 sec, p less than 0.01). Tp was prolonged for more than 10 sec in the infarcted region. Tc in the marginal region was markedly prolonged compared to Tc in the control region (7.4 +/- 0.9 vs 4.4 +/- 0.5 sec, p less than 0.025). Tc could not be determined in the infarcted regions because data acquisition time of our apparatus was inadequate.(ABSTRACT TRUNCATED AT 250 WORDS)

To evaluate the usefulness in diagnosing coronary artery disease (CAD), dipyridamole-loading 201T1 myocardial scintigraphy was performed for 52 elderly patients (65-92 years, mean: 72 years), and the results were compared with data from the treadmill exercise tests. Thirty-five patients could not tolerate adequate exercise tests. Seven of them had reversible defects; six, fixed (irreversible) ones. Dipyridamole scintigraphy is therefore applicable in detecting CAD among patients with suspected CAD who are unable to perform adequate exercise tests. Four of 16 patients with positive exercise tests had no reversible defects; the exercise results in three were regarded as false positives. Seventeen patients experienced chest pain; 12 had ST depression during dipyridamole loading. There were no serious complications, but seven patients required aminophylline. We demonstrated previously that the sensitivity and specificity of dipyridamole scintigraphy in detecting CAD were 90% and 92%, respectively, in patients with chest pain undergoing coronary angiography. These results were superior to those of conventional exercise myocardial scintigraphy. Therefore, dipyridamole scintigraphy is regarded as a safe and useful method for detecting CAD, particularly in elderly patients who have ST and T wave abnormalities but cannot tolerate exercise test adequately.

Left ventricular relaxation property was evaluated by pulsed Doppler echocardiography. The indices obtained from Doppler signals within the left ventricle (LV) during the isovolumic relaxation period (IRF) were compared with the hemodynamic parameters obtained from cardiac catheterization studies. Subjects of this study were four patients with hypertrophic cardiomyopathy, four with hypertensive heart disease, three with angina pectoris, and seven normal subjects. All of them had no wall motion abnormalities and their ejection fractions were more than 0.60. The three indices of IRF were the time interval from the start of IRF to the time immediately before the rapid filling flow (isovolumic relaxation time; IRT), the time interval from the start to the peak (acceleration time; AcT), and the slope from the start to the peak (acceleration rate; AcR). The peak pressure (peak P) was measured at the same time. The positive and negative deflections of the first derivative of left ventricular (LV) pressure (+dp/dt and -dp/dt) and the time constant of LV pressure fall (time constant T) were calculated from LV pressure using a micromanometer-tipped angiocatheter. The end-diastolic volume index (EDVI), end-systolic volume index (ESVI), and ejection fraction (EF) were calculated from the LV angiogram. There were no significant correlations between the three IRF indices (IRT, AcT and AcR) and the hemodynamic parameters (peak P, EDVI, +dp/dt and -dp/dt). However, the time constant T, which is a good index of LV relaxation property and which is relatively free from afterload and preload, correlated well with IRT (r = 0.75, p less than 0.001), AcT (r = 0.60, p less than 0.01), and AcR (r = -0.66, p less than 0.01). It was concluded that the indices obtained from the blood flow patterns of the left ventricle during isovolumic relaxation were useful for estimating left ventricular relaxation property non-invasively and quantitatively.

To elucidate the physioanatomic roles of the pericardium, the alterations in gross anatomy and cardiac motion induced by posture were examined by two-dimensional echocardiography in seven patients with total absence of the left pericardium. Ten healthy subjects were served as controls. The heart was located deeper within the chest at end-diastole in patients with pericardial defect than in healthy subjects, especially in the left lateral decubitus position. With progression of systole, the cardiac apex swung anteriorly with the cardiac base as the fulcrum, and the heart approximated the normal position at end-systole. The deeper the position of the center of the cross-section of the left ventricular cavity at end-diastole, the more exaggerated the swinging motion in systole. The deep location of the heart in end-diastole is considered to result from release from pericardial support, and the systolic tonus of the cardiac muscle restores the apex to nearly normal position. The characteristic swinging motion of the heart and its alterations dependent of posture seemed the signs suggestive of total absence of the pericardium. The shape of the short-axis view of the left ventricular cavity was nearly circular throughout the cardiac cycle. Therefore, paradoxical motion of the ventricular septum observed on M-mode echocardiography in pericardial defect results from the anterior shift of the entire heart overcoming the proper motion of the interventricular septum. The left ventricular dimension become enlarged according to the postural change from the right to left lateral decubitus positions regardless of the presence or absence of the pericardium. The right ventricular cavity became enlarged in the left lateral decubitus position in patients with pericardial defect. The elevation of hydrostatic pressure due to postural change was considered excessive due to the absence of the pericardium. In the left lateral decubitus position, systolic excursions of the mitral and tricuspid rings became more prominent in healthy subjects, whereas these excursions, particularly of the tricuspid ring, were reduced in patients with pericardial defect. Depressed tricuspid ring motion was also observed in the right lateral position in cases with pericardial defects. The reduced excursion of the tricuspid, ring and the right ventricular dilatation may affect systemic venous return to the right atrium.

A 67-year-old man with a sigmoid septum causing the left ventricular outflow obstruction by inotropic stimulation was reported. This patient was admitted to the Hospital of the University of Tsukuba because of chest pain. Phonocardiography revealed a systolic ejection murmur which was intensified by amyl nitrite inhalation. A carotid pulse tracing showed a mid-systolic dip and a secondary slow wave during amyl nitrite inhalation. M-mode echocardiography demonstrated neither systolic anterior motion of the mitral valve (SAM) nor mid-systolic closure of the aortic valve at rest. Two-dimensional echocardiography revealed a basal interventricular septum markedly protruding into the left ventricle (sigmoid septum). The remainder of the septum and the left ventricular free wall were not hypertrophied, and no enlargement of the left ventricular cavity was observed. During exercise tests, blood pressure dropped significantly. Cardiac catheterization showed a pressure gradient within the left ventricle with isoproterenol infusion and post-extrasystolic potentiation. These findings suggest that left ventricular outflow tract obstruction could occur in a patient with sigmoid septum by inotropic stimulation, producing a fall of blood pressure during exercise.

Acute myocardial infarction (AMI) is relatively rare in systemic lupus erythematosus (SLE), although other cardiac complications, such as pericarditis and myocarditis, occur frequently in this disease. A 20-year-old woman with documented SLE experienced a transmural anterior AMI due to thrombi in saccular aneurysms of the left main coronary artery and the proximal portion of the left anterior descending coronary artery. There were also saccular and fusiform aneurysms in the right coronary artery, but thrombi were not observed in them. Aorto-coronary bypass surgery was performed to salvage the viable myocardium and to prevent recurrent myocardial infarction and rupture or infection of these coronary aneurysms. Postoperative coronary angiography revealed a new small saccular aneurysm in the mid-portion of the right coronary artery. During this period, there was no immunological evidence of active SLE. It is important to ascertain whether such coronary aneurysms resulted from atherosclerosis or arteritis, because of the choice of the different therapeutic interventions. In this case, however, it was difficult to determine. It was speculated that these coronary aneurysms arose from an arteritic process, because the saccular aneurysm in the mid-portion of the right coronary artery was formed in less than three months, there were no coronary risk factors, and any microscopic evidence of atherosclerosis was not obtained in the aortic specimen during aortocoronary bypass surgery. Serial coronary angiographic studies are necessary for accurately diagnosing coronary artery disease. Anticoagulant therapy and antiinflammatory medication may be necessary to prevent myocardial infarction in patients with SLE, even if there is no immunological evidence of active SLE.

Evaluation of regional contractile reserve and the viability of an infarcted segment of the myocardium is very important in determining the indications for aorto-coronary bypass after myocardial infarction and in predicting the prognosis. Regional wall motion of the left ventricle after postextrasystolic potentiation (PESP) was studied in 18 patients with old myocardial infarction, and compared with indices of redistribution of thallium after exercise. Equilibrium radionuclide angiocardiography (RNA) using Tc99m HSA was performed at rest and after PESP produced by a programmable cardiac stimulator via a right ventricular catheter. Regional ejection fractions (REF) were determined, and wall motion was observed visually. The relative thallium activity (RTA) and washout rate (WOR) were obtained from exercise myocardial scintigraphy performed 10 minutes, and 3 hours after thallium-201 injections. Wall motion improved in 12 of 23 infarcted segments after PESP. Regional ejection fraction and relative thallium activity (in three hours, or the difference between the activities of the initial and three hours after exercise) in the improved segments were significantly higher (p less than 0.001) than in the unchanged segments. Washout rate was lower (p less than 0.02) in the improved segments. Significant correlation was observed between the change in regional ejection fraction and relative thallium activity (3 hours after exercise) (r = 0.654, p less than 0.05). Thus, the wall motion of some infarcted regions of the myocardium improved after PESP, and thallium was redistributed during three hours after exercise.(ABSTRACT TRUNCATED AT 250 WORDS)