The changes in endothelium-derived vascular regulatory factors during dobutamine (DOB)-induced myocardial ischemia (MI) were investigated in 21 patients with Kawasaki disease aged from 11 months to 18 years. They were classified into an ischemia group (8 patients) and a non-ischemia group (13 patients) based on the results of ^99mTc myocardial scintigraphy and DOB stress ^99mTc myocardial scintigraphy. In the ischemia group, MI was relatively mild, because there were ischemic changes on the electrocardiogram and no significant symptoms during DOB stress. Catheters were positioned near the orifice of the coronary artery (Ao) and at the coronary sinus (CS). Hemodynamics and the blood concentrations of lactic acid and endothelin-1, as well as NO₃^-, 6-keto-prostaglandin F_{1 α}, and thromboxane B₂, (which are inactive metabolites of nitric oxide, prostaglandin I2 and thromboxane A₂, respectively), were measured at rest and after DOB stress (maximum dose: 30μg·kg^-1 ·min^-1). The CS/Ao ratio was determined for all parameters. The rate-pressure product, an index of work load, and the cardiac index were significantly increased by DOB stress in both groups. Coronary angiography showed no vasospasm of the epicardial coronary arteries before or after DOB stress in either group. The plasma concentrations of endothelin-1 and 6-keto-prostaglandin F_1α were significantly increased after DOB stress in the ischemia group, but the serum concentration of NO did not increase. The lack of an increase in NO production during DOB stress may have contributed to the worsening of MI in patients with Kawasaki disease. (Jpn Circ J 1999; 63: 503 - 508)

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Multivessel spasm in variant angina is believed to be a major prognostic factor. Three patterns of multivessel spasm have been detected: (1) spasm at different sites on different occasions (migratory spasm); (2) spasm sequentially affecting 2 different sites (sequential spasm); and (3) simultaneous spasm at more than 1 site (simultaneous spasm). The present study investigated the prognosis based on this factor for variant angina without fixed coronary stenosis and examined the influence of multivessel spasm on cardiac events. Twenty-six patients were diagnosed as having variant angina without fixed coronary stenosis using 12-lead 24-h ECG recording system and coronary cineangiography. These patients were followed up prospectively for 57.1±7.6 months. Of the 26 patients 13 had single-vessel spasm, 6 had migratory multivessel spasm angina, and 7 showed sequential and/or simultaneous multivessel spasm angina. The survival free of serious cardiac events and of all cardiac events was significantly lower for patients with sequential and/or simultaneous multivessel spasm than for those with migratory multivessel spasm (p<0.05, p<0.05), whereas for patients with migratory multivessel spasm the difference comparison with single-vessel spasm did not attain statistical significance (p=ns, p=ns). The results of this study suggest that there seems to be a high-risk subgroup (ie, sequential and/or simultaneous multivessel spasm) among patients with variant angina. (Jpn Circ J 1999; 63: 509 - 513)

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The aim of this study was to clarify the acute performance of steroid-eluting screw-in leads in comparison with that of nonsteroid screw-in leads for atrial free wall pacing. In 114 cases (68 males, 46 females, average age 70 years) with atrial free wall pacing by screw-in leads, pacing thresholds and P-wave amplitudes were compared at the time of implantation and 1 week later between 68 cases of nonsteroid and 46 cases of steroid-eluting screw-in leads. No significant differences were seen between the 2 groups at implantation in either voltage or current thresholds measured at pulse widths of 0.1, 0.3, 0.6, 1.0, 2.0 ms, or P-wave amplitudes. Pulse width thresholds at outputs of 2.5 V and 5.0 V were significantly lower for steroid leads 1 week after implantation (2.5 V: 0.34±0.27 ms nonsteroid vs 0.12±0.08 ms steroid, p<0.001; 5.0 V: 0.12±0.08 ms nonsteroid vs 0.06±0.02 ms steroid, p<0.01). P-wave amplitudes after 1 week were significantly higher for steroid leads (2.6±0.7 mV nonsteroid vs 3.0±1.2 mV steroid, p<0.001). Threshold rise, including pacing failure, was observed in 15 (22%) of the nonsteroid leads, but in only 1 (2%) of the steroid leads. In conclusion, steroid-eluting screw-in leads suppress the acute rise of pacing thresholds in the right atrial free wall and their acute performance is better than that of nonsteroid leads. These results suggest that appropriate low-output atrial pacing is feasible immediately after implantation. (Jpn Circ J 1999; 63: 514 - 516)

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The poor sensitivity and the poor predictive value of ST-segment depression have limited the usefulness of the exercise electrocardiogram (ECG) in the diagnosis and evaluation of coronary artery disease (CAD). The QT dispersion (QTD), recorded as the difference between maximal and minimal QT intervals on a 12-lead exercise ECG, is sensitive to myocardial ischemia and may improve the accuracy of exercise testing in patients with CAD who do not show an ST-segment depression. Exercise ECGs were analyzed in 50 subjects who had undergone coronary angiography for clinical indications. None of them showed an ST-segment depression during or after exercise: There were 25 patients with significant coronary artery stenosis and 25 without significant stenosis. The QTD measured before, immediately after, and 1 min after exercise was similar in the 2 groups. The QTD at 3 and 5 min after exercise was significantly greater in patients with CAD than in the controls, and the most marked difference in QTD was observed at 3 min after exercise. A QTD at 3 min after exercise of >60 ms had a sensitivity of 80% and specificity of 88% regarding the diagnosis of CAD. When a ΔQTD (post-exercise QTD minus QTD at rest) at 3 min after exercise of >0 ms was added to a QTD of >60 ms as a condition for positivity, the specificity increased to 96%. QTD measured at 3 min after exercise increases the accuracy of exercise testing in patients with CAD who do not show an ST-segment depression. (Jpn Circ J 1999; 63: 517 - 521)

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The morphology of atherosclerosis between the carotid and coronary artery systems was studied in 63 patients with ischemic heart disease to determine if there was a correlation with coronary heart disease. The sclerotic lesions of the carotid and coronary artery systems were imaged with ultrasonography and coronary arteriography, respectively, and divided into 4 types. Hemodynamic variables, serum lipid levels, and serum uric acid concentration were not different among the groups, but the serum C-reactive protein (CRP) concentration in patients without significant atheroma in the carotid artery system was lower than the mean concentration of the other 3 groups with carotid atheroma. The morphological stability of carotid arterial plaques correlated well to coronary artery stenosis. Morphologically unstable plaques of the carotid artery predicted unstable forms of coronary obstruction with a sensitivity of 68%, specificity of 85%, predictive power of 72% and a likelihood ratio of 4.5. These results suggest that ultrasonic examination of the carotid artery is useful for predicting the presence or absence of unstable lesions in coronary arteries. (Jpn Circ J 1999; 63: 522 -526)

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The purpose of this study was to establish the safest way to bathe patients with myocardial infarction (MI) through measuring the hemodynamics during and after bathing. Seventy patients with MI were bathed supine in a Hubbard tank filled with 42°C tap water for 5 min. The subjects were divided into 2 groups depending on their hemodynamic values 10 min after bathing: pulmonary capillary wedge pressure unchanged even after bathing (group A), and decreased pressure after bathing (group B). The left ventricular ejection fraction of group B was significantly higher than that of group A: 53.6% vs 39.7%, respectively (p<0.01). The physical work capacity of group B was significantly higher at 5.6 METs, than that of group A with 4.5 METs (p<0.05). During the average of their 37-month follow-up period, there were 3 cardiac events in group B and 6 in group A. There were 2 cardiac events during bathing, both of which occurred in group A. When patients with MI take a bath, it is essential to closely monitor them, especially to those patients with lower cardiac function, because they have a higher possibility of a cardiac event. (Jpn Circ J 1999; 63: 527 - 532)

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There are cases in which it is thought advisable to avoid the use of the left internal thoracic artery (LITA) in coronary artery bypass grafting (CABG) due to its low free flow (FF). However, even though the LITA flow is very low, anastomosis without any further maneuvers intraluminally is recommended. The present study investigated the clinical results of CABG, using a LITA with low FF. The 60 cases of CABG were divided into 2 groups: (i) Group L (n=23), in which LITA FF was less than 20 ml/min; and (ii) Group H (n=37), in which it was more than 20 ml/min. A comparative study on the basis of coronary angiography and pulsed Doppler echocardiography was performed. In both groups, no LITA graft occlusion was identified, and the `string sign' was also absent. In the LITA blood waveform, all cases exhibited a biphasic pattern with a higher mid-diastolic and a lower end-systolic component. There were no significant differences in the LITA flow diastolic peak velocity, velocity time integrals and the diastolic/systolic peak velocity ratios. These results suggest that the LITA can be used for CABG even when the free flow is less than 20 ml/min. (Jpn Circ J 1999; 63: 533 - 536)

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In vitro experimental models of branch orifices jailed by various stents were created to estimate the safety and the efficacy of rotational atherectomy when rotational burrs were advanced through the struts of stents. The scaffolding structures of the stents were destroyed due to loss and deflection of the struts, and the size of ablated stent-particles differed: the maximal size was 1.7 mm in slotted stents, and 17.6 mm in coiled stents. Thus, there is a definite potential for ablating stents when rotational atherectomy of restenotic lesions of side-branch orifices jailed by stents is performed. (Jpn Circ J 1999; 63: 537 - 541)

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5-Amino-4-imidazole carboxamide (AICA) riboside increases adenosine release in ischemic myocardium, suggesting that AICA riboside improves contractile dysfunction. In 49 open-chest dogs, contractile function assessed by fractional shortening (FS) was observed 3 h after the onset of reperfusion following 15 min of occlusion of the left anterior descending coronary artery. During reperfusion, the treatment with AICA riboside increased adenosine concentration in the coronary venous blood (536±44 vs 281±21 pmol/ml at 3 min of reperfusion, p<0.001) and peak coronary hyperemic flow (367±13 vs 300±21 ml/100 g per min, p<0.001) when compared with the untreated group. FS at 3 h of reperfusion increased in the AICA riboside group (21.1 ±2.3 vs 12.8±0.6% in the untreated group, p<0.001). AICA riboside increased myocardial ecto-5'-nucleotidase activity. Administration of adenosine also augmented coronary hyperemic flow and increased FS to the levels of the AICA riboside group. Either 8-phenyltheophylline (an antagonist of adenosine receptors) or α,β-methyleneadenosine 5'-diphosphate (an inhibitor of ecto-5'-nucleotidase) completely abolished the increased coronary hyperemic flow and improvements of myocardial contractile function due to AICA riboside. Thus it was concluded that AICA riboside improves the contractile dysfunction that follows a brief period of ischemia via adenosine-dependent mechanisms. (Jpn Circ J 1999; 63: 542 - 553)

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Vasospastic angina as a result of alcohol ingestion has been reported, but the mechanism of alcohol-induced coronary artery spasm is presently unknown. This report presents 2 cases of alcohol-induced variant angina (VA) with elevated levels of plasma endothelin-1 after alcohol ingestion. In case 1, the plasma endothelin-1 concentration was 3.15 pg/ml before drinking (normal <2.30 pg/ml) and increased to 4.09 pg/ml when measured 5 h after alcohol ingestion. After 2 months of abstinence, the plasma endothelin-1 concentration was 2.88 pg/ml and 6 months after abstinence, it decreased to 2.03 pg/ml (normal range). In case 2, the plasma endothelin-1 concentration was 2.44 pg/ml before drinking and increased to 4.36 pg/ml when measured 5 h after alcohol ingestion. After 2 months of abstinence, the plasma endothelin-1 concentration was 3.04 pg/ml and 6 months after abstinence, it decreased to 2.09 pg/ml (normal range). These 2 cases suggest that a relationship may exist between alcohol-induced VA and elevation in the plasma endothelin-1 concentration after alcohol ingestion. (Jpn Circ J 1999; 63: 554 - 558)

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A 56-year-old man presented with an inferior myocardial infarction and a huge pseudoaneurysm below the inferior surface of the left ventricle, which had progressed from a small subepicardial aneurysm over a 6-month period. Transthoracic echocardiography, Doppler color flow images, radionuclide angiocardiography, magnetic resonance imaging and contrast ventriculography all revealed an abrupt disruption of the myocardium at the neck of the pseudoaneurysm, where the diameter of the orifice was smaller than the aneurysm itself, and abnormal blood flows from the left ventricle to the cavity through the orifice with an expansion of the cavity in systole and from the cavity to the left ventricle with the deflation of the cavity in diastole. Coronary angiography revealed 99% stenosis at the atrioventricular nodal branch of the right coronary artery. At surgery the pericardium was adherent to the aneurysmal wall and a 1.5-cm orifice between the aneurysm and the left ventricle was seen. Pathological examination revealed no myocardial elements in the aneurysmal wall. The orifice was closed and the postoperative course was uneventful. Over-intense physical activity as a construction worker was considered to be the cause of the large pseudoaneurysm developing from the subepicardial aneurysm. These findings indicate that a subepicardial aneurysm may progress to a larger pseudoaneurysm, which has a propensity to rupture, however, it can be surgically repaired. (Jpn Circ J 1999; 63: 559 - 563)

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Aortocaval fistula (ACF) is a rare complication of spontaneous abdominal aortic aneurysm (AAA) rupture, with an incidence of 2-4%. A unique case of ruptured AAA complicated by multiple aortovenous fistulas involving the inferior vena cava and left internal iliac vein is presented, and is the first published report of a patient with Ehlers-Danlos syndrome undergoing surgical treatment for an ACF. (Jpn Circ J 1999; 63: 564 -566)

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A 76-year-old male was admitted to hospital complaining of severe abdominal pain, constipation, nausea and vomiting. The patient had undergone stent graft placement of an abdominal aortic aneurysm (AAA) at another hospital 13 months prior to admission. An X-ray, computed tomography scan and barium-enema examination revealed partial obstruction of the duodenum. Stent graft placement has been reported to be a useful procedure for AAA. However, as mass effects associated with AAA cannot be excluded, several symptoms may remain postoperatively. (Jpn Circ J 1999; 63: 567 - 568)

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A patient with severe long-standing Takayasu's arteritis underwent successful replacement of the aortic root and ascending aorta with a cryopreserved aortic homograft. Her postoperative course was uneventful and echocardiography demonstrated evidence of neither aortic regurgitation nor graft detachment more than 2 years after the operation. Magnetic resonance image demonstrated no signs of graft enlargement. (Jpn Circ J 1999; 63: 569 - 571)

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A 23-year-old woman with heterozygous Fabry's disease who had acroparesthesia was admitted to hospital for precise examination of the disease before childbearing. She had no cardiac-related symptoms and no abnormality on physical examination. The α-galactosidase A activity in her leukocytes was present, but lower than normal. However, the endomyocardial biopsy showed specific changes for Fabry's disease. As Fabry's disease is a rare X-linked recessive inborn error of glycosphingolipid metabolism, heterozygous females are usually asymptomatic, but rarely can be affected as severely as hemizygous males. This is an isolated case of heterozygous Fabry's disease in a female in whom cardiac involvement was detected by endomyocardial biopsy, although she had no cardiac abnormality on physiological examinations. In conclusion, endomyocardial biopsy is useful for evaluation of the cardiac involvement of Fabry's disease even in an asymptomatic case. (Jpn Circ J 1999; 63: 572 - 575)

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