A new portable noninvasive recorder (4×6.5×14cm in size, 390g in weight) was developed for monitoring 24-hour blood pressure and its clinical applicability was investigated. Employing an ordinary-size cuff, this is the lightest and the most compact apparatus of its kind ever developed. It is powered by a rechargeable battery. The cuff is pressurized by a miniature, low-noise, rotary micropump. To eliminate noises resulting from body motion, two microphones are used to distinguish Korotkoff sounds. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) are measured automatically at intervals of 1 to 60 min throughout 24 hours. These data can be stored as many as 600 times in the recorder's semiconductor memory. After measurement, mean values; standard deviations (SD); and trendograms of SBP, DBP, and HR are printed out by means of an appurtenant, miniature analyzer measuring 5×7.5×15cm.
A comparison of values obtained with this new instrument and the values obtained with a conventional auscultatory method showed average errors of -1.2±4.7 (SD)mmHg for SBP and -2.7±5.0mmHg for DBP. The correlation coefficient (r) of values obtained by two methods was r=0.99 for SBP and r=0.96 for DBP (n=185). In 38 male and 31 female normotensive subjects (average casual BP: male 126±11/76±7mmHg; female 116±13/69±10mmHg), average 24-hour BP values recorded by the new recorder were 115±7.5 (SBP)/70±6 (DBP)mmHg for the males and 106±6/63±5mmHg for the females. The new recorder seems to be convenient, easy to operate, and clinically useful in ambulatory monitoring.

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In order to investigate the abnormalities in intracellular sodium concentration ([Na]i) in essential hypertension, [Na]i in lymphocytes and erythrocytes was determined in 37 outpatients with essential hypertension and 35 normotensive controls matched for sex and age. [Na]i in lymphocytes was higher in hypertensive patients than in normotensive controls, while no difference was observed in [Na]i in erythrocytes between the 2 groups. There was no significant correlation between [Na]i in lymphocytes and erythrocytes in either group. In hypertensive patients, plasma renin activity had a negative correlation with [Na]i in lymphocytes, but not with [Na]i in erythrocytes. These results suggest that the increase in [Na]i may be associated with essential hypertension with suppressed plasma renin activity and that lymphocytes are more suitable than erythrocytes for the analysis of [Na]i.

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To clarify the mechanism of stress-induced ST segment elevation in patients with previous anterior myocardial infarction, we examined myocardial lactate metabolism during atrial pacing in 32 patients with previous anterior myocardial infarction (MI group) and 11 control subjects (control group). In the MI group, atrial pacing resulted in new or additional ST segment elevation in leads with Q waves in 15 patients (ST elevation group), ST segment depression in 7 (ST depression group), but induced no appreciable ST segment changes in the remaining 10 patients (ST unchanged group). In all patients, the ST segment changes were identical to the results of exercise stress testing which was carried out prior to the atrial pacing. Lactate extraction ratio increased moderately during the atrial pacing in the control group (p<0.01). Although marked reduction of the myocardial lactate extraction ratio was noted in the ST depression group (p<0.05), no significant change in the ratio was evoked in the ST elevation group or the ST unchanged group during atrial pacing. Left ventricular end-diastolic pressure (LVEDP) increased markedly in the ST depression group during atrial pacing, but the elevation was less evident in the other groups. The ST elevation group demonstrated the lowest left ventricular ejection fraction and the severest degree of left ventricular asynergy. Thus, the present study indicates that aggravated left ventricular asynergy in the infarcted area and associated left ventricular dysfunction, rather than peri-infarction zone ischemia is a possible mechanism of stress-induced ST segment elevation in leads with Q waves following previous anterior myocardial infarction.

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Sequential electrocardiographic changes in 31 patients with Duchenne's muscular dystrophy (DMD) during a long-term follow-up study (over 7 years) were investigated.
The patients were classified into 2 groups according to sequential changes in amplitude of the R wave in lead V1 (RV1): group I, in which RV1 decreased with age, and group II, in which it showed no consistent change with age. Group I consisted of 14 patients who died earlier (19±1 years) than those in group II (22±3 years). The highest RV1 values were similar in the 2 groups, but high RV1 values appeared at an earlier age in group I (10±3 years) than in group II (16±4 years). The amplitude of the R wave in lead V5 (RV5) decreased with age in both groups, and then increased at the age of 21 to 24 years in group II.
The R/S ratio and depth of the Q wave did not show a consistent change during the follow-up period in most DMD patients.
These results indicate that sequential changes in RV1 and RV5 are useful indicators of the severity of heart injury in DMD.

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The purpose of this study was to define the clinical features of acute myocardial infarction in a group of elderly Chinese. The presenting symptoms, complications and mortality of acute myocardial infarction were compared in 631 patients (430 men and 201 women) aged 60 and over and 389 patients (333 men and 56 women) whose ages were under 60 years. The incidence of painless myocardial infarction was 17.6% in the elderly versus 5.9% in the younger group. Typical chest pain was present in 63.1% of the elderly and 84.3% of the younger Chinese. However, the incidence of other nonspecific presenting symptoms was higher in the elderly group. Likewise, the major complications in the elderly group were more severe than those in the younger group. For example, the incidences of cardiogenic shock, heart failure, arrhythmia, pulmonary infection and cardiac rupture in the older group were 19.8, 24.2, 77.2, 22.0 and 4.4%, versus 15.1, 19.5, 48.1, 9.5 and 1.1% in the younger group, respectively. The immediate (4 week) mortality rate of the older group was 21.9% (over 80 years 51.5%), but was only 11.0% in the younger group. Although the incidences of hypertension and pulmonary disease were significantly greater in the elderly group, these diseases alone did not account for the higher mortality rate in the elderly.

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The purpose of this study was to investigate the efficacy, effective dose, administration frequency and antianginal effect of a new antianginal agent, nipradilol, in 12 patients with stable effort angina. A single blind design was employed; the test consisted of an observation period (1 week) and a treatment period (1-2 weeks). Twenty four hour Holter monitoring was performed on the penultimate day of each period. Nipradilol was administered twice a day at a daily dose of 3-12mg (mean 7.9±3.3mg). The mean frequency of ST-segment depression was 7.1±6.7 times per day at baseline and 3.1±2.7 after drug administration, showing a significant reduction (p<0.05). The suppression of ST-segment depression and decrease in heart rate due to this drug persisted for 12 hours following administration. The plasma drug concentration at a daily dose of 12mg peaked at 9.5±2.4ng/ml 1 hour after administration and the 12 hour value was 2.3±1.2ng/ml. No side effects were observed. Therefore, it seems that, when administered twice a day (total daily dose 6mg) this drug is effective in effort angina and that the antianginal effect is mainly attributable to β-adrenoceptor blockade.

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The electrophysiological effects of intravenous propranolol (0.15mg/kg) were studied in 26 patients with sinus node dysfunction (SND group) and 9 patients with normal sinus node function (control group). Spontaneous cycle length and AH interval were significantly increased in the control and SND groups after propranolol. PA and HV intervals, calculated sinoatrial conduction time and refractory periods of the atrium, AV node and ventricle were not significantly changed in either group. Maximum corrected sinus node recovery time (max CSRT) was not changed in the control group, but it was significantly prolonged in the SND group. These results of the overdrive suppression test were in disagreement with those of previous studies. Propranolol lengthened spontaneous cycle length (by more than 200 msec) and/or max CSRT (by more than 1000 msec) in 8 of 26 patients with SND. Thus, it is suggested that propranolol should be used with caution in patients with SND.

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The clinical effects of diltiazem in 15 patients with congestive cardiomyopathy were observed. Symptoms were controlled in 66% and cardiac enlargement improved in 73.3%. There was a decrease in cardiac silhouette on X-ray in 18.82±3.2% (p<0.01), with an increase of EF(%), CO, CI and a decrease of TPR on two-dimensional (2-D) echocardiogram (p<0.01). Prior to treatment, the cardiac status of 8 cases was grade III and 7 cases grade IV; after treatment 1 case was grade I, 8 grade II, 5 grade III and 1 grade IV. This improvement might be due to the blockade of calcium channels and the fact that diltiazem has the least negative inotropic effect among the calcium antagonists. The dosage, route of administration, and prevention of side effects are discussed.

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Ventricular pressure-volume area (PVA) is a specific area in the pressure-volume diagram, which represents the total mechanical energy generated by each contraction, consisting of stroke work and mechanical potential energy at end-systole. Animal experiments have shown that PVA is correlated linearly with the ventricular oxygen consumption (Vo₂) per beat under a variety of loading conditions in a stable contractile state. The slope of the Vo₂-PVA line has been shown to remain constant in different contractile states, implying a constant stoichiometry between Vo₂ and PVA. As a first step to understand the nature of this Vo₂-PVA relation, we devised a new crossbridge (CB) model to theoretically relate PVA with the total enthalpy change associated with the ATP hydrolysis for all CB cycles. One of the most important assumptions on which this model analysis depended was that the time-varying elasticity model could simulate the instantaneous pressure-volume relation. The result of this analysis implied that the empirical linear Vo₂-PVA relation could be attributed to the energy balance between energy input and output of the chemomechanical transduction associated with CB cycles during a ventricular contraction.

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Nitroglycerin is considered to decrease both preload and afterload. To elucidate the actions of nitroglycerin on afterload, venous return was kept constant in this experiment. Three different doses of nitroglycerin, 0.3μg/kg/min, 1.0μg/kg/min, 3.0μg/kg/min were administered into the ascending aorta of 6 mongrel dogs weighing over 20kg. These doses of nitroglycerin were randomized in each of six procedures. The plasma concentration of nitroglycerin increased during 10 min of infusion, then it decreased exponentially. Heart rate, cardiac output and left atrial pressure did not change significantly at any dose of nitroglycerin. Systolic blood pressure and systemic vascular resistance (as indices of afterload) decreased significantly during nitroglycerin infusion, especially with the 3μg/kg/min dose. These data suggest that nitroglycerin decreases the afterload. The effects appeared rapidly with administration and disappeared rapidly after cessation of the infusion.

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The relationship between the amount of myocardium rendered ischemic, the risk zone, and the percentage of that zone which ultimately infarcts (%I/R) was examined in the closed chest canine model. Twentythree dogs were anesthetized with pentobarbital. A special cannula was inserted through a carotid artery into the left coronary ostium. A teflon bead was infused through the cannula, thus, embolizing a distal coronary branch. Two to 8 minutes after the coronary embolization, 20 million radiomicrospheres labeled with ¹⁴¹Ce (15μ in diameter) were injected into the left ventricle. This allowed the collateral blood flow in the risk zone to be measured and defined the ischemic zone. The dogs were sacrificed either 24 or 48 hours after coronary occlusion and the hearts were excised and sectioned into 5mm thick slices. The risk zones were visualized by microsphere autoradiography while the infarcts were visualized by triphenyl tetrazolium staining. The volumes of both zones were determined by planimetry. Experiments were retrospectively divided into either a small risk zone group (risk zones smaller than 18% of the ventricle, n=13) or a large risk zone group (risk zones larger than 18% of the ventricle, n=10). There was a very close correlation between the %I/R and collateral blood flow in both the small and the large risk zone groups (Y=90.85-1.07X, r=-0.88 vs Y=88.84-0.91X, r=-0.93). That correlation was not statistically different between the 2 groups. These findings indicate that risk zone size itself does not influence the percentage of the risk zone which is infarcted in this model.

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An infant with a supracardiac type of total anomalous pulmonary venous return associated with pulmonary artery sling is reported. Twodimensional echocardiography can provide an accurate diagnosis of these two rare types of congenital cardiac lesion prior to esophagography and cardiac catheterization.

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A 30 year old man with DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) syndrome associated with myocardial disease is reported. Echocardiographic study revealed a marked symmetric left ventricular hypertrophy. Histology of the endomyocardial biopsy specimen from the right ventricle showed severe glycogen deposition in the myocytes. This case may indicate that DIDMOAD syndrome is a hereditary systemic disease affecting multiple organs, including the myocardium.

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A case of Marfan's syndrome associated with Wolff-Parkinson-White (WPW) syndrome is described and a discussion follows on the possible relationship of the two conditions. Isolated cases of such an association have been previously reported.^{1), 2)} It is possible that the association is more common than was previously recognized and the two conditions may share a common pathological basis. Moreover, WPW syndrome may contribute to the cardiac morbidity of Marfan's syndrome.

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In this paper we report the first adult case of an "idiopathic" ventricular bidirectional tachycardia (BT), in a 57 year old woman. The tachycardia, at the time of our observation, was incessant in type and had a slightly irregular frequency of about 140 bpm. BT initiated and terminated abruptly, without any temporal relationship to the preceding RR interval, or the QRS morphology. The interval between the two alternating QRS patterns often varied over a wide range of values. The BT could be interrupted only by overdrive atrial and ventricular stimulation, but promptly reappeared as pacing was discontinued. Therapy with quinidine associated with propranolol was effective on a long term trial. The vectorcardiographic analysis and the electrophysiologic investigation demonstrated a ventricular origin of the BT, localizing its site of origin to common myocardial tissue, probably near the two left hemifascicles. Our data could not elucidate the electrogenetic mechanism of this ventricular arrhythmia, because of its chaotic behavior.

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The case of a 69 year old man with a right adrenal pheochromocytoma who manifested cyclic fluctuations of blood pressure with a cycle length of 9 to 13 min is reported. We collected and reviewed 14 similar cases previously reported in the literature. In these cases, right adrenal pheochromocytoma was most common, while 1 case involved the left adrenal and 2 cases were of extra-adrenal origin. The incidence in males was twice that in females and the median age was 45.3 years. Although a good correlation between the blood pressure and plasma norepinephrine concentrations was observed in our patient, the exact mechanism for the cyclic fluctuations of blood pressure is not known. In our patient, both YM-09538 and bunazosin were effective in controlling severe hypertension preoperatively. YM-09538 induced significant increases in urinary norepinephrine concentrations (1327±238μg/day), while bunazosin induced a significant decrement in urinary norepinephrine concentrations (475±188μg/day) compared with pretreatment levels (900±42μg/day) (p<0.01). These observations indicated that bunazosin as a postsynaptic α-adrenergic receptor blocker interfered with release of norepinephrine from the tumor and thus might be beneficial in the management of elevated blood pressure in patients with pheochromocytoma.

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