The left ventricular (LV) wall motion was assessed in 66 patients with ischemic heart disease and other diseases by means of real-time, phased-array, cross-sectional echocardiography (ECHO). The LV wall was divided into 7 anatomic segments, according to the AHA Committee Report, and the motion of each segment (a total of 462 segments) was compared with that in the cineangiographic observation (ANGIO). Two tomographic planes, corresponding to the LAO and RAO views of ANGIO, were employed in ECHO. The LV chamber volume and ejection fraction (EF) were calculated from the RAO plane by an arealength method.
The following results were obtained; (1) The motions of 414 segments (89.6%) were visualized by ECHO. The apical area showed the poorest visualization. (2) Three hundred and ninety segments (94.2%) showed a concordant finding between ECHO and ANGIO. Twentyfour slight discrepancies were noted. (3) Calculated LV volume and EF were well correlated with the results from ANGIO (r=0.84 and 0.88, respectively), even in the presence of LV asynergy.
It was concluded that ECHO was an useful method for detecting the LV asynergy and the determination of the LV functional parameters. Discrepancies between ECHO and ANGIO in the assessment of the LV asynergy might well be attributed to some factors including the difference between the methods, that is, non-invasive and invasive.

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The change in the left atrial dimension during diastole was examined in patients with mitral stenosis using echocardiography. The left atrial emptying fraction (LAEF), defined as the ratio of enddiastolic dimension to endsystolic dimension of the left atrium, was 0.65±0.03 (mean±SE) for normal subjects, 0.86±0.01 for low grade mitral stenosis, and 0.92 ±0.01 for high grade stenosis. The LAEF correlated well with mitral valve area index (r=-0.70), but the correlation between E-F slope of the anterior mitral leaflet and mitral valve area index was less significant (r=0.48). In patients who received mitral valve replacement the LAEF and the left atrial dimension significantly improved.
The left atrial emptying fraction is an easily obtainable and reliable index to estimate the severity of mitral stenosis, even in patients who have undergone mitral valvular surgery.

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Electrophysiological studies were performed to see the effects of lidocaine on the conduction system, particularly sinus node and atrium in 40 patients of SSS, using HBE recordings, rapid atrial pacing and atrial extrastimulus technique. Sinus cycle length, PA (P'A), AH, HV intervals, calculated SACT, and refractory periods of atrium, AV node and His-Purkinje system did not change after lidocaine. Only maximum CSRT was significantly increased with lidocaine. These results were not affected by pretreatment of atropine.
In conclusion, the combining rapid atrial pacing with lidocaine may be useful to manifest the masked sinus node abnormalities. It was suggested that lidocaine directly depressed sinus node automaticity in SSS patients, without affecting perinodal tissue. Therefore, lidocaine should be used with caution in patients with known or suspected SSS.

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Influence of vasodilator therapy on prognosis of acute myocardial infarction complicated by left heart failure (in Killip classes II and III) was studied in 22 aged patients (mean age; 75.7 years). The patients were retrospectively divided into 2 groups: Group I; 12 patients were treated with isosorbide dinitrate and/or chlorpromazine and Group II; 10 patients were treated with other conventional medical measures. Initial hemodynamic changes on admission were not significantly different between 2 groups.
With these treatments mortality rate within 2 weeks of treatment was lower in Group I than in Group II (p<0.01), however, cumulative cardiac mortality rate within 18 months did not differ significantly. The present study demonstrated beneficial influence of vasodilator therapy on early prognosis in aged patients, but failed to show prolonged influence on later mortality.

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The efficacy on congestive heart failure of metildigoxin (β-methyldigoxin, MD), a derivative of digoxin (DX), which had a good absorption rate from digestive tract, was examined in a double blind study using a group comparison method. After achieving digitalization with oral MD or intravenous deslanoside in the non-blind manner, maintenance treatment was initiated and the effects of orally administered MD and DX were compared. MD was administered in 44 cases, DX in 42. The usefulness of the drug was evaluated after 2 weeks, taking into account the condition of the patient and the ease of administration. No significant difference was observed between the usefulness of MD and that of DX.
The use of digitalis differs according to the preparation involved. In the double blind study on MD and DX, the way in which digitalis was used may have inclined towards the way in which DX, which is more familiar to us, is used. Therefore, even if MD were superior to DX in usefulness, it would be difficult to obtain a result which proved this. Taking these points into consideration, it is concluded that MD is practically useful in clinical medicine.

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The fluctuations of base line of the electrocardiogram (ECG) in man with chronic atrial fibrillation (f waves) were considered as random signals. Simultaneously recorded ECGs from several points on the chest wall, in the esophagus and the right intracardiac cavities were regarded as multiple statistical time series. A spectral matrix was computed from them, and the number and location of the f wave generators and the direction of the circulating excitation wave were estimated or determined by principal component analysis of the spectral matrix, and further multiple and partial coherences between the f waves of simultaneous ECGs were computed. Then, the following conclusions were obtained: 1. The number of generators for the f waves was one and this generator was apparently located somewhere in the right atrium. Stimuli from here generated a circulating excitation wave which descended in the right atrium and ascended in the left. Further, the number of generators was one, which was clearly interpreted from the values of multiple coherences. Therefore, it was evidently demonstrated that f waves were produced by neither ectopic impulse formation nor microre-entry but by macrore-entry (circus movement) in addition to the presence of one generator (focus), as supported also by mere inspection of simultaneously recorded ECGs. 2. In reference to the results of computer simulation conducted hitherto by several authors, it was postulated that atrial fibrillation was initiated by an appropriate premature beat and the perpetuation of this arrhythmia was maintained by a circulating excitation wave, but from the present investigation and the theory recently advanced by Cranefield, one focus persistently sending out impulses at a certain frequency in one direction only could be thought necessary for the initiation and possibly for the perpetuation of atrial fibrillation.

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The F waves in the electrocardiogram (ECG) of a patient with common type of atrial flutter were considered as random signals. Simultaneously recorded ECGs from several points on the chest wall were regarded as multiple time series. The number and location of the F wave generators and the direction of circus movement were estimated or determined by applying principal component analysis of the spectral matrix. Further, the multiple and partial coherences between the F waves of simultaneous ECGs were calculated and the following conclusions were obtained: 1. The number of generators for the F waves was one and this generator was assumed to be located somewhere in the right atrium. The differences in the shapes of the F waves recorded on the body surface were due merely to the differences of recording locations. On the other hand, the F waves could be satisfactorily explained by the optimum linear combination of the other leads as indicated from the values of the multiple coherences, which led also to the conclusion of the existence of one generator. 2. The F wave generator propagates a unidirectional circulating excitation wave which progresses in the left atrium in a caudo-cranial direction and in the right in a cranio-caudal direction, but does not send out impulses radially in all directions as suggested by conventional ectopic focus hypothesis. Therefore, atrial flutter in man could be assumed to be initiated and possibly maintained by one ectopic focus (generator for the F waves) but perpetuation of this arrhythmia by circus movement could not be decisively demonstrated in the present context. 3. Mathematical treatment on the multiple time series which have various phase differences depending upon the recording locations and are often encountered in biology and medicine was succinctly explained. 4. The present study is a sort of inverse problem in electrocardiography as performed by time series analysis and principal component analysis in the frequency domain.

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We examined the effects of new long acting coronary vasodilators (dilazep and SG 75) on cyclic nucleotides in the coronary artery and the myocardium at the maximum coronary blood flow. The cyclic AMP concentrations in the anterior descending coronary artery after the injection of saline (control), SG 75 (0.2mg/Kg), and dilazep (0.1mg/Kg) were 229±20pmole/Gm, 249±21pmole/Gm, and 320±21 pmol/Gm, respectively. A significant increase above control values was found in the dilazep treated group (p<0.02). The cyclic GMP concentrations in the coronary artery after the injection of saline, SG 75, and dilazep were 35.6±4.4pmole/Gm, 40.4±3.3pmole/Gm, 35.3±3.2pmole/Gm, respectively. There were no significant differences between them. The cyclic AMP and cyclic GMP concentrations in the left ventricular muscle did not significantly increase after the administration of dilazep and SG 75. Our findings showed that the mechanism of coronary vasodilating action of dilazep might be associated with an increased cyclic AMP in the coronary artery.

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The effects of angiotensin converting enzyme inhibitor (CEI) upon blood pressure and plasma aldosterone (PA) were studied in rabbits with a simultaneous infusion of angiotensin I (ANG I) or with hemorrhagic hypotension.
Pretreatment with CEI (SQ 20881), 1.0mg/Kg, inhibited the effects of infused ANG I, 30ng/Kg/min, upon PA and blood pressure at 30min of the infusion, but the inhibition on PA was not significant at 60min of the infusion. The same dose of CEI was ineffective in blocking the effect of 100ng/Kg/min of ANG I on PA and blood pressure even at 30min of the infusion.
In rabbits with hemorrhagic hypotension, injection of CEI resulted in the decrement in blood pressure, whereas no decrement in blood pressure was observed in normal control rabbits.

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In order to reveal the mechanism of renin inhibition by beta adrenergic blocking agents, the effects of dl-, d-, l-propranolol and pindolol on renin release were studied. This was done by injecting them intraperitoneally or by using an in vitro system of rat kindey slices.
In the in vivo study, dl-, d-, and l-propranolol inhibited plasma renin activity and renal renin content significantly in normal rats. Furthermore, in the in vitro study, the basal levels of renin in the media and that in the kidney were significantly inhibited by these agents. Pindolol also inhibited renin release, but its effects were significantly less than those of other agents. The finding that d-propranolol which has little beta adrenergic blocking action inhibited renin release, and that the effects of pindolol which displays strong beta adrenergic blocking action but little membrane stabilizing action, were less than those of other agents, may suggest that the inhibitory effects of beta adrenergic blocking agents on renin release are dependent mainly on the membrane stabilizing action rather than the beta adrenergic blocking action.

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The etiology of congenital heart lesions is varied and multifactorial hypothesis has gained wide acceptance. Regardless of the etiologic agent, the offending factor must act through a common pathway by either changing the growth rate, the resorptive process or the molding mechanical effect of the circulating blood. In search of a model for producing congenital heart disease in a reproducible fashion we used 8-azaguanine (a purine analogue) to study the effects of growth inhibition on developing chick embryo hearts. One half ml of 8-azaguanine (25mg% solution) was injected into the yolk sac of fertile white Leghorn eggs at 23rd stage. Eggs injected with 1/2ml of normal saline served as control. Eight-azaguanine-treated eggs delivered less normal embryos (29/188) than the saline-injected eggs (119/158, p<0.001) and more dead embryos (106/188 vs 0/158 respectively, p<0.001). Serial sections of the hearts extracted at 35th stage in the 8-azaguanine-treated (64 specimens) and control group (96 specimens) revealed no congenital heart defect in the latter group, whereas the development of the hearts were halted either in the tubular stage (12/64, p<0.01) or in the primitive stages of development (28/64, p<0.001). The thickness of the ventricular myocardium was also greatly reduced.
It is concluded that: 1) Certain types of congenital heart defects such as endocardial cushion defect, and common ventricle could be reproducibly produced by growth inhibiting agent 8-azaguanine in the chick embryo. 2) Experimental models for production of congenital heart defects through acceleration of the growth or changing the rate of tissue resorption must be sought.

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Effects of bradykinin on SA node pacemaker activity and atrial contractility were studied, using isolated, blood-perfused dog atrium preparations. Bradykinin (0.1-100μg) caused a slightly but consistently positive chronotropic action, although it did not produce a consistent inotropic action. When successive doses of bradykinin were given in a short period, these preparations displayed tachyphylaxis. Bradykinininduced action was not suppressed by a potent β-adrenoceptor blocking agent, carteolol. In addition, kallikrein (0.1-3 units), was administered into the sinus node artery to investigate the effect of endogenous kinins. Kallikrein had no effect on SA node pacemaker activity nor atrial contractility at any examined doses. On the other hand, a kallikrein inhibitor, aprotinin, induced dose-relatedly a negative inotropic and chronotropic effect at a dose range from 100 to 3, 000 units. These negative actions of aprotinin were not blocked by an adequate dose of atropine.
From these results, it is concluded that bradykinin has a slight direct positive chronotropic effect, and that aprotinin has direct negative inotropic and chronotropic effects in the isolated, blood-perfused canine atrium in a wide dose range.

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The variant form of angina pectoris (VA) is a rather common disease in Japan, and the author himself is suffering from it. Among 100 successive cases of various types of angina seen in our Department, excluding myocardial infarction and post-infarctional angina, 23 cases were VA. The brief duration, cyclic occurrence and frequent incidence of the attacks at night are considered to be the clinical characteristics. The pathogenesis of VA is ascribed to coronary spasm on the basis of findings made in cinecoronary arteriography. ST elevation was observed more frequently on exercise test in VA than in ordinary exertional angina pectoris, indicating that patients with VA are in a markedly spasmophilic state. Although the prognosis is not generally so serious, 33 out of 50 cases of VA had arrhythmias during attacks, including such serious ones as advanced AV block and ventricular fibrillation. Nifedipine was dramatically effective in suppressing repeatedly occurring ventricular fibrillation. A survey of the effects of calcium antagonists in 243 cases of VA in 11 cardiology institutes throughout Japan revealed that these drugs were effective in more than 90% of the cases. Of particular note is the fact that the attacks were completely eliminated in more than 80% of the cases.

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This report describes a case with flail right and noncoronary cusps due to bacterial endocarditis, diagnosed with real-time two-dimensional echocardiography. Real-time two-dimensional phased array sector scanner demonstrated 2 cugdel-shaped lesions in the region of the left ventricular outflow tract through the aortic root, pendulating upward and downward floating along the blood stream. This study shows that the real-time two-dimensional echocardiography is a very useful noninvasive tool in the early diagnosis of flail aortic valve.

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