The interatrial septum (IAS) has not been readily appreciated by M-mode echocardiography, but cross-sectional echocardiography has the capability of recording the shape and location of the IAS.
Thirty-five patients with secundum atrial septal defect (ASD) were studied with cross-sectional echocardiography for detection of the ASD defect and demonstration of the IAS features following ASD closure.
The ASD was shown as an echo dropout at the mid-portion of the septum in those patients examined in the present study in the horizontal cross-sections at the fourth intercostal space. The edges of the remaining IAS sharply demarcated and the defect was constantly demonstrated. In the postoperative patients, the IAS was recognized as a smooth series of echoes and the defect was no longer recognized. A notch echo was demonstrated in patients who underwent direct suture of the defect, and two notch echoes were recorded in patients who had a patch closure from a cardiac operation.
The size of the defect at cardiac operation ranged from 1.5 to 5.0cm with an average of 3.3±0.2cm. The defect was slightly smaller on cross-sectional echocardiograms than at the time of operation. As the defect grew larger, the right ventricular dimension and the Qp/Qs became larger as well. Postoperatively, the right ventricular dimension was remarkably decreased, and the paradoxical movement of the interventricular septum (IVS) was normalized in the majority of the patients.
Cross-sectional echocardiography is useful to diagnose ASD, to measure the size of the IAS defect, and to follow the clinical course.

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The usefulness of automaticity recovery time (ART) and automaticity recovery phase (ARP; the time requiring P-P cycles to return to the original P-P cycles following the termination of tachyarrhythmias) for evaluating the sinus node function was studied in 24 patients with tachyarrhythmias by recordings of 24-hour continuous electrocardiograms. Automaticity recovery time was not so valuable in evaluating sinus node function because the overlap of ART was observed between patients of normal sinus node function and patients with sick sinus syndrome. The pattern of ARP was classified into 4 types (I-IV). Type I showed quick return to the original P-P after overdrive suppression, type II was characterized by first suppression and secondary acceleration, type III was the pattern characterized by repeated suppression after tachycardic overdrive, and type IV was characterized by repetitive appearance of tachyarrhythmia and bradycardia. The period of each ARP was measured and the period of type II (42.2±16.6sec) or III ARP (48.4±21.4 sec) was significantly longer than type I (22.1±11.1sec). Type III ARP was considered to suggest sinus node dysfunction.
In conclusion, it was suggested that not only the observation of ART but also ARP were valuable for evaluating more precise sinus node function. The observation of ARP is easily obtained from 24-hour continuous recordings of electrocardiograms.

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The superior and inferior vena cava flow velocities (SVC and IVC flow velocities) of 3 patients with anomalous pulmonary vein connection were recorded with the Doppler flowmeter catheter. The cases consisted of a patient with partial anomalous pulmonary vein connection to the SVC (Case 1), one with total anomalous pulmonary venous connection to the SVC (Case 2), and one with partial anomalous pulmonary vein connection to the IVC (Case 3).The SVC and IVC recordings of these patients were compared with those of 10 normal subjects, 20 patients with atrial septal defect and 150 patients with other heart diseases.
The SVC and IVC flow velocities in the latter group of 180 patients showed a biphasic pattern, having systolic (S) and diastolic (D) waves, the peak S wave occurring around midsystole. In Cases 1 and 2, the SVC flow velocity showed a markedly delayed peak S wave, similar to the pattern of the pulmonary vein flow velocity; this pattern was also seen in the IVC flow velocity in Case 3. This abnormal pattern could be useful in diagnosing anomalous pulmonary vein connection.

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We attempted to clarify the pathogenesis of asymmetric ventricular hypertrophy in hypertensive patients, especially regarding sympathetic nervous system and renin-angiotensin system. Subjects were divided in 3 groups by echocardiographic findings; 1) 15 patients with non-hypertrophy (NH), 2) 14 patients with symmetric hypertrophy (SH), and 3) 10 patients with asymmetric hypertrophy (ASH).
Subjects with ASH showed following features. Age (53.7±1.6yr) was older than NH (43.7±1.4yr) but not different from SH (49.7±2.3yr). Mean arterial pressure (119.0±3.9mmHg) was higher than NH (107.5±1.4mmHg) but not different from SH (122.4±2.8mmHg). End-diastolic and end-systolic dimensions were smaller and ejection fraction was larger than those of NH and SH. Cardiac index (3.90±0.37L/min/M²) was largest among 3 groups. U_NE (19.5±3.5μg/day) was lower than SH (31.2±2.5μg/day). PRA (0.44±0.16ng/ml/h) was lower than SH (1.53±0.20ng/ml/h) and NH (1.62±0.28ng/ml/h). Ejection fraction was correlated with U_NE (r=0.835) and PRA (r=0.736).
We suggest that the heart of hypertensives with ASH is in hyperdynamic state due to the hyperresponsiveness to sympathetic stimuli, although they have a decrease of sympathetic nervous activity, and the renin-volume axis may have no important role on the pathogenesis of ASH.

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An angiotensin converting enzyme inhibitor, captopril (or SQ 14225), was administered orally to 23 hypertensive patients under a constant sodium and potassium diet. It resulted in reduction of plasma aldosterone concentration which was related significantly to the increase of serum potassium level (r=-0.533), but only weakly to the reduction of plasma angiotensin II level (r=0.474). Aldosterone level remained suppressed in the face of increased serum potassium. The effects on aldosterone level and potassium were greater in patients with high plasma renin activity than in those with low and normal plasma renin activities. They also paralleled the reduction in blood pressure. It is suggested that reduction in aldosterone level and potassium retention were caused by blockade of angiotensin II formation by captopril, but the potassium retention was additionally influenced by renal impairment.

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Elevated plasma renin activity was found in 6 out of 7 essential hypotensive patients. This was taken to reflect some abnormality in sodium handling, and they were treated with synthetic calcium glycyrrhetinyl-glycinate (G. G.), a water soluble derivative of glycyrrhetinic acid which was derived from licorice. G. G. was administrated in doses of 300mg to 1200mg daily for 3 to 9 weeks. Both the systolic (25.8±10.0mmHg) and diastolic (19.2±9.8mmHg) blood pressure successfully elevated and improvement or resolution of clinical symptoms was noted in 6 patients. Marked supression in plasma renin activity (2.7±1.2ng/ml/hr) and plasma aldosterone concentration (8.1±3.1ng/100ml) with mild reduction in serum potassium concentration (1.0±0.4mEq/L) were concomitantly observed. One patient did not respond at all to G. G. Adverse reactions were mild in all but one who had frank edema.

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This study was designed to simultaneously evaluate the effects of alterations in aortic pressure (AoP) on regional myocardial function and regional myocardial blood flow (MBF) in anesthetized dogs with partial coronary occlusion. Regional myocardial function was assessed by both segment-length and tension gauges. The left circumflex coronary artery flow was reduced to 50 to 70% by a constrictor. When systolic aortic pressure (AoPS) fell from 103.6±7.4 to 72.5±4.9mmHg following nitroprusside infusion, systolic shortening (SS) markedly depressed from 0.63±0.17 to 0.09±0.20mm (p<0.01), developed tension (DT) decreased by 30% (p<0.01), and MBF assessed with tracer microspheres decreased from 0.61±0.13 to 0.36±0.11ml/min/Gm (p<0.01) in ischemic regions. In non-ischemic regions SS was enhanced from 0.78±0.16 to 0.89±0.15mm (p<0.05), but DT and MBF showed no changes. An elevation of AoPS from 106.4±5.6 to 143.3±6.9mmHg following methoxamine infusion brought about enhanced SS from 0.42±0.15 to 0.48±0.09mm (p<0.05), a 50%-increase in DT (p<0.01), and was associated with an increase in MBF from 0.66±0.03 to 1.19±0.07ml/min/Gm (p<0.01) in ischemic regions.
These results indicate that, in partial coronary occlusion, a fall of AoP induces redistribution of blood flow away from ischemic regions and aggravates the function of the ischemic myocardium, while an elevation of AoP may produce beneficial effects upon the ischemic myocardium.

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Effects of 4-aminopyridine (4-AP) and tetraethylammonium (TEA) on vasodilator actions of 2-nicotinamidoethyl nitrate (SG-75) were investigated using isolated dog coronary arteries. SG-75 10^-8-10^-4Gm/ml produced concentration-dependent relaxations of coronary arterial strips which were contracted with potassium 30mM or prostaglandin (PG) F_2α 10^-6Gm/ml. Both 4-AP 5×10^-4Gm/ml and TEA 1.6×10^-3Gm/ml produced further contractions of the strips under potassium- or PGF_2α-contracture. The potency to constrict the strips was greater in 4-AP than in TEA. 4-AP 5×10^-4Gm/ml and TEA 1.6×10^-3Gm/ml did not affect the SG-75-induced relaxations of the strips under potassium-contracture, but significantly depressed them under PGF_2α-contracture. In the strips under a resting state, 4-AP 5×10^-4Gm/ml increased tension and produced oscillations in their contractions, but TEA 1.6×10^-3Gm/ml did not. Results suggest that SG-75 may display its relaxant effect on isolated dog coronary arteries in part through an increase in potassium conductance.

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The effects of aminophylline and pentoxifylline were investigated on the blood pressure and heart rate in the intact dog and on the atrial rate and contractile force in isolated atrial muscle which was perfused with arterial blood of the donor dog. Firstly, each drug was intravenously administered to the donor dog. Both compounds produced a dose-dependent hypotension. Aminophylline frequently caused bradycardia in intact dogs and positive chrono- and inotropic effects in isolated atria. However, pentoxifylline usually produced only tachycardia in the donor dog and positive chrono- and inotropic effects on the isolated atrium. When the compounds were administered into the sinus node artery, positive chrono- and inotropic effects were induced, with aminophylline being approximately 3-10 times more potent than pentoxifylline.
Larger doses of aminophylline or pentoxifylline when administered intravenously might cause a release of catecholamine, because increased sinus rate and developed tension in isolated atria which was perfused with donor's blood were partially, but significantly, suppressed by propranolol treatment.
In the isolated atrium, aminophylline, but not pentoxifylline, significantly inhibited the negative chronotropic and inotropic effects of adenosine.

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This paper deals with a patient with recurrent ventricular tachycardia which was completely controlled with drugs following surgical resection of the arrhythmia focus. Details of epicardial and endocardial mappings are described.

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Hypertrophic cardiomyopathy, which is sometimes familial and genetically transmitted as an autosomal dominant trait, is generally regarded as a disease of young or middle aged and relatively few cases have been reported in elderly patients. The present communication describes the oldest known siblings with clinically diagnosed hypertrophic cardiomyopathy, 80 and 78 years of age.

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A case of cardiac sarcoidosis survived 12 years after development of overt heart failure, which was the longest record hitherto reported. The survival after major cardiac involvement was probably much longer, since he had an attack of syncope 7 years before heart failure. He died of ventricular fibrillation at age 59. Progression of myocardial sarcoid involvement may be slower in some patients than has previously been believed.

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A male newborn expired 5 days after birth, because of multiple congenital cardiac anomalies. The postmortem examination demonstrated tricuspid stenosis, pulmonary atresia, hypoplastic right ventricle, persistent venous valve, and so on. In addition, he had coronary arterio-ventricular fistulous connection, associated with absence of the proximal connection of the coronary artery to the aorta or the pulmonary artery. As the result, the coronary blood was totally supplied via the right ventricular-coronary channels. Histologic examination revealed that these arterio-luminal channels were characterized by sinusoidal mural structure.

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