Japan has experienced great socioeconomic development together with industrialization urbanization and motorization since 1945. This has resulted in dramatic changes in both the frequency of disease and the spectrum of diseases, as well as in a rapid increase in the elderly population. Changes in eating patterns during the past 40 to 50 years seem to be a major factor in this evolution. Departure from the traditional Japanese diet, which was very high in salt and low in fat and protein (currently the diet is 25% calories from fat, 60% from carbohydrate and 15% from protein and 12 gm salt/day), has been associated with a reduced incidence of stroke, but not with an increase in coronary heart disease mortality. Therefore, the current Japanese diet may be an optimal eating pattern for maintaining health. However, since the exposure to increased fat calories is recent, future trends must be carefully monitored.

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To determine the benefits of coronary artery bypass grafting (CABG) in elderly patients, we evaluated 37 patients more than 70 years old who underwent this surgical procedure and compared the results with those in 177 younger patients. Three-vessel lesions and left main lesion were seen in 78.4% and 48.6% of the elderly patients, respectively. Emergency or urgent surgery was performed on 19 patients and the number of distal anastomoses was 3.0±0.8 per patient. Left main lesion and emergency surgery were more common in elderly patients than in younger patients. Twelve patients received CABG with only a saphenous vein graft (SVG), while the remaining 25 patients had at least one arterial graft. The quality of the saphenous vein was poor to moderate in 50% of the elderly patients, while none of the arterial grafts showed significant sclerotic change. In 17 elderly patients, the ascending aorta showed sclerotic lesions and care was taken when completing proximal anastomoses of SVG to the aortic wall. After surgery, mechanical ventilation was required for an average of 29 h, which was longer than that in the younger patients. Postoperative low cardiac output, hypertension, and arrhythmia occurred in 6, 6 and 15 elderly patients, respectively. There were no early deaths, although there was one hospital death due to posttransfusion hepatitis. Thirty four elderly patients were classified as New York Heart Association functional class I or II during late follow-up maximum of 5 years) and only one had postoperative angina. The ascending aorta showed more sclerotic lesions, and the quality of the saphenous vein was worse, in the elderly patients. However, improvement after CABG was satisfactory for the elderly patients and pedicled arterial grafts appeared to decrease surgical risks even for the elderly.

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We evaluated the patterns of interruption of atrial flutter (AFl) induced by rapid atrial pacing in 10 patients using standard electrophysiologic techniques. We observed 3 patterns of interruption of AFl: 1) interruption resulting from block of an orthodromic wavefront within the reentry loop in 5 patients; 2) interruption when pacing impulses no longer captured all of the recording sites in the atrium during rapid atrial pacing in 2 patients, and 3) interruption with 1 echo wave after the cessation of pacing in 3 patients. These findings suggest that there are patterns of interruption of AFl other than that resulting from a simple block of an orthodromic wavefront within the reentry loop.

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One hundred patients with frequent (>1, 000 beats/day) ventricular premature contractions (VPCs) were followed for 4 years. All of the patients, except those with non-cardiac death (n = 8), were classified into 3 groups based on their outcome. Group A consisted of 29 patients with idiopathic VPCs who survived the study period. Group B consisted of 49 patients with underlying diseases who survived the study period. Group C consisted of 14 patients who suffered cardiac death. There was no significant difference in the daily number of VPCs. However, groups B and C had more patients with Lown grade 4a or 4b VPCs than group A. The mean coupling interval was significantly longer in group C than in group A, and the standard deviation of the coupling interval was significantly larger in group C than in group A. Forty patients underwent serial Holter monitorings to assess changes in the number of VPCs. VPCs spontaneously decreased in 13 patients, while the other 27 patients continued to have frequent VPCs. Most of these 13 patients were classified as Lown grade 2. The results suggest that in patients with frequent VPCs, longer and more varied coupling intervals may predict a poor prognosis, and Lown grade 2 may predict a spontaneous regression.

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In patients who received thrombolytic therapy for acute myocardial infarction (AMI), we observed 3 distinct patterns in gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA)-enhanced magnetic resonance (MR) imaging. To clarify the significance of these distribution patterns of Gd-DTPA, 20 consecutive patients underwent Gd-DTPA-enhanced MR imaging 7-10 days after AMI. All of the patients received intravenous recombinant tissue plasminogen activator (IVTPA) within 6 h of onset. Echocardiograms were obtained prior to and serially over 10 days, and interpreted for regional wall motion. Coronary angiograms were obtained the day before discharge. None of the 6 patients with a closed infarct-related artery, and 9 of the 14 patients with an open artery, demonstrated subendocardial enhancement (p<0.05). All of these latter 9 patients demonstrated a significant improvement in wall motion between days 1 and 10 after AMI. In contrast, only 1 of the 7 patients with transmural enhancement and none of the 4 patients with non-homogeneous enhancement demonstrated improvement of wall motion on day 10 (p<0.05). We concluded that subendocardial enhancement was a fair prognostic sign for restoration of regional cardiac function in patients who received IVTPA during AMI .

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To evaluate the diagnostic value of a transient dilatation of the left ventricle during dipyridamole-thallium imaging (DTI) for detecting significant coronary artery disease (CAD) in patients with negative DTI results, 81 consecutive patients were studied. Twenty one patients (26%) had CAD and 60 patients had normal coronary anatomy (NCA). The initial/delayed ratio of the left ventricular dimension, which was measured as the distance between the 2 peaks of a count profile curve on a 45° left anterior oblique planar image, was defined as the dilatation ratio (DR) of the left ventricle. Patients with CAD had a higher incidence of chest pain after dipyridamole infusion (35 vs 13% ; p<0.05), and ST depression during exercise testing (50 vs 25%; p<0.05) than those with NCA. DR was significantly greater in CAD patients than in NCA patients (1.08±0.10 vs 0.97±0.03; p<0.0001). DR was considered abnormal (>1.03) when it was greater than the mean +2 standard deviations of the DR in NCA patients. Seventy-six percent of CAD patients had an abnormal DR. A stepwise discriminant analysis revealed that an abnormal DR alone had the same ability to predict CAD (sensitivity 76%, specificity 98%, chi-square 80.9, p<0.0001) as the best combination of abnormal DR, chest pain during exercise testing, age and gender (sensitivity 76%, specificity 98%, chi-square 98.5, p<0.0001). When abnormal DR was excluded from this analysis, the best combination of the variables showed a reduced ability to predict CAD (sensitivity 81%, specificity 77%, Wilks' Lambda 0.71, chi-square 26.7, p<0.0001). In conclusion, an abnormal DR (>1.03) is a highly specific marker for detecting CAD, even in patients with negative dipyridamole-thallium imaging.

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The purpose of this study was to examine the effects of microwave catheter ablation of ventricular myocardium. Microwave energy with a frequency of 2450 MHz was delivered via a coaxial catheter with an electrode ball tip. Microwave energy was applied to canine isolated left ventricular endocardium in vitro and to 6 anesthetized dogs in vivo at 50 watts for 15-150 sec. Ventricular arrhythmia was not observed during ablation in any of the dogs when microwave energy was applied for less than 45 sec. When the duration of microwave ablation was greater than 45 sec, ventricular premature contractions were observed in all of the dogs. Nonsustained ventricular tachycardia developed when the duration of microwave delivery was greater than 90 sec. After the cessation of ablation, ventricular arrhythmias did not occur and ventricular programmed stimulation did not induce ventricular tachycardia in any of the dogs. Except for ventricular arrhythmia, no declines in the hemodynamic status were observed in any of the 6 dogs. The size of the ablated lesion was significantly greater as the duration of ablation was increased (p<0.05). When ablation lasted for more than 120 sec, the coagulation layer was extended to the epicardium in all 6 dogs. The results of this study suggest that microwave ablation is feasible for the treatment of tachyarrhythmias from deep focus of ventricular myocardium with relatively small proarrhythmic effects.

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We present a patient with metastatic cardiac leiomyosarcoma that was diagnosed antemortem by transesophageal echocardiography (TEE) and ECG-gated magnetic resonance imaging with gadolinium diethylene triaminepentaacetic acid (Gd-DTPA MRI). TEE and Gd-DTPA MRI clearly revealed the morphological characteristics of infundibular stenosis and cardiac tamponade. Our patient has survived about 30 months after cardiac surgery. Since sarcoma is usually associated with a very poor prognosis, surgical treatment should be performed as soon as possible. TEE with color Doppler imaging and Gd-DTPA MRI are very useful diagnostic methods for determining the precise anatomical characterization of cardiac tumor, and these procedures are prerequisite to precise therapy.

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