In 52 patients with reentrant monomorphic sustained ventricular tachycardia (VT), the site of VT origin was determined by endocardial mapping and the interval from stimulus artifact to the onset of QRS complex (StQRS) was measured during pace-mapping. Eleven patients had remote myocardial infarction (group 1), 25 patients had other underlying heart diseases (group 2), and 16 had idiopathic VT (group 3). A St-QRS interval of 40msec or longer was defined as abnormal. (1) Long St-QRS interval: Thirteen sites with long St-QRS intervals were detected in 13 (25.0%) of 52 patients: 5 patients in group 1 (45.5%), 7 (28.0%) patients in group 2 and one (6.3%) in group 3. (2) Local electrogram: The local electrogram at sites with a long StQRS interval was wide and 113±38msec in duration during sinus rhythm which increased to 159±64msec during VT (p<0.05). In sinus rhythm, an abnormally prolonged local electrogram was observed in 11 of 13 sites with a long St-QRS interval, and mid-diastolic potential or continuous activity was observed in 3 sites during VT. (3) Relation to VT origin: At sites with a long StQRS interval, concealed entrainment was observed in 3 patients, and the earliest activated local electrogram during VT in 5 patients. Conclusion: Sites with a long ST-QRS interval were observed in 25% of the patients with VT, and their incidence tended to be higher in patients with ischemic heart disease. Such sites were associated with abnormal local electrograms and some of the sites were considered to be the active limb of the reentry circuit.

抄録全体を表示

Patients with chronic heart failure symptoms tend to avoid voluntary effort and are thus subject to physical deconditioning. The presence of symptoms in daily life is thought to predispose to physical deconditioning and subsequent skeletal muscle loss. This study was designed to describe the relation among daily physical activities, skeletal muscle loss and exercise capacity in patients with chronic heart failure. We studied 14 patients with severe cardiac dysfunction (left ventricular ejection fraction<40%) and 7 age-matched normal subjects. We measured total leg muscle mass by dual energy X-ray absorptiometry. The patients were divided into 7 asymptomatic and 7 symptomatic individuals using questionnaires for specific physical activities. Peak oxygen uptake and anaerobic threshold were significantly reduced in cardiac patients as compared with normal subjects. The reduction in exercise capacity was greater in the symptomatic patients than in asymptomatic patients. Leg muscle mass was significantly reduced (-17%) in the symptomatic patients, while it remained normal in the asymptomatic patients. Oxygen uptake in unit muscle mass at the level of anaerobic threshold and at peak exercise was decreased in both the asymptomatic (-21% and -21%, respectively) and symptomatic patients (-27% and -30%, respectively) but the difference between these two groups was not significant. In the asymptomatic patients, the reduced exercise capacity was accounted for primarily by muscle mass-independent factors such as an impaired nutritive blood flow to exercising muscles or metabolic abnormalities within the muscle cell. In the symptomatic patients, the marked reduction in exercise tolerance was attributable to a decrease in leg muscle mass and to hemodynamic or metabolic abnormalities. We conclude that the loss of leg muscle mass plays an important role in exercise intolerance in patients who are prone to physical deconditioning as a result of symptomatic heart failure.

抄録全体を表示

The density of cardiac β-adrenoceptors (Bmax) was measured in eighteen patients [2 with atrial septal defect (ostium secundum), 4 with aortic valve disease, 3 with mitral valve disease, 1 with aortic and mitral valve disease, 5 with a history of myocardial infarction, and 3 with angina pectoris] following mild to moderate cardiac failure. Measures were obtained by cardiac catheterization prior to cardiac surgery and also during the surgical procedures. On the basis of symptoms immediately preceding surgery, the severity of the condition in each patient was categorized as either Class I (n=5) or Class II (n=13) following the New York Heart Association (NYHA) functional classification system. The Bmax was measured using right atrial appendage tissue obtained during cardiac surgery. [¹²⁵I]-iodocyanopindolol was used for the assay. The Bmax of atrial cell membranes in patients with NYHA class II was significantly lower than that of class 1 (34.1±2.5 vs 55.4±9.3 fmol/mg protein, M±SE, p<0.05). Correlation coefficients between the Bmax and hemodynamic parameters measured just prior to cardiac surgery were examined, but only that between Bmax and the minimum value of the time derivative of left ventricular pressure (max negative dp/dt) was significant (r=-0.552, p<0.05). Further study is needed to understand and clarify the relationship between Bmax and dp/dt min.

抄録全体を表示

To evaluate postprandial hemodynamic changes, Doppler measurements of stroke volume before and after lunch were carried out in 10 healthy volunteers (all men) with a mean age of 28 years. The stroke volume was calculated as the product of echocardiographically determined aortic valve area and the ejection flow velocity integral obtained by continuous wave Doppler. The stroke volume before lunch was 61±7ml, which was increased to 72±8ml 1 hour after lunch and remained constant for the next 4 hours. Five hours later the stroke volume was then decreased to the baseline. M-mode echocardiography revealed an increase in left ventricular end-diastolic dimension and ejection fraction after lunch.
Another 9 healthy subjects (6 women and 3 men) with a mean age of 52 years received a 75g oral glucose tolerance test (OGTT) instead of a common lunch; stroke volumes were not altered in association with the elevation of plasma glucose level.
In conclusion, ingestion of food had a positive inotropic effect and caused circulating blood volume expansion with an increment of heart rate. Therefore, Doppler studies that are not standardized for patients' mealtimes may affect the validity of data in serial studies of left ventricular function.

抄録全体を表示

Partial anomalous pulmonary venous return (PAPVR) is a congenital anomaly in which one or more, but not all, of the pulmonary veins are connected to a systemic vein or to the right atrium directly. Its incidence is higher in autopsy series than in clinical series.
We report 51 cases of PAPVR diagnosed by cardiac catheterization and evaluated from the aspects of age, sex, type and associated anomalies and diseases.

抄録全体を表示

The aim of this study was to investigate the pharmacokinetics of propranolol in patients with hyperthyroidism, and its effect on heart rate (HR) using 24 hour-ECG monitoring. Subjects included 9 patients with hyperthyroidism (group H) and 9 euthyroid patients with hypertension selected as the control group (group C). All patients took propranolol at a dosage of 10mg, 3 times a day for 7 days. Plasma propranolol concentrations were measured on the 7th day of its administration by the HPLC method. Twenty-four hour-ECG monitoring was recorded twice before and after treatment with propranolol. The mean reduction in the minimum HR was 10.7±3.6 (11.9±3.6%) in group H and 5.0±1.6 (9.5±3.0%)bpm in group C. That in the average HR was 12.2±3.7 (11.3±3.1%) in group H and 9.2±2.2bpm (13.7±3.2%) in group C. That in the maximum HR was 16.9±5.2 (10.9±3.1%) in group H and 24.4±2.4bpm (21.9±2.1%) in group C. The peak concentration of propranolol in plasma was 10.8±2.4ng/ml in group H and 55.3±14.3ng/ml in group C (p<0.01). There was a linear correlation between the reduction in the hourly maximum heart rate and the peak plasma propranolol concentration in group H. Cardiovascular manifestations in hyperthyroid patients were related to sympathetic hypersensitivity and their improvement was not fully obtained by small doses of propranolol.

抄録全体を表示

Vesnarinone is a new, non vasodilating cardiotonic agent. This study compared the effects of vesnarinone and amrinone, a phosphodiesterase (PDE) inhibitors with vasodilating actions, on cultured smooth muscle cells from the porcine coronary artery. Application of vesnarinone (10^-4M) or amrinone (10^-4M) to the bath solution in cell-attached patches activated the K_Ca channel having a conductance of 133 pS (bath 2.7mM K, pipette 140mM K). Application of vesnarinone to the cytosolic side had no direct effect on KCa channel activities in inside-out patches. Activation of the KCa channel was suppressed when the intracellular production of cAMP was suppressed by preincubation with carbachol (10^-6M). Amrinone, but not vesnarinone, lowered [Ca²⁺]i in the K⁺-depolarized smooth muscle cells (K⁺=70mM). These results suggest that vesnarinone exerts an additional effect on [Ca²⁺]i that is independent of PDE inhibition. The difference in the effects on [Ca2+]i in vascular smooth muscle cells may explain in part the differing actions of these agents on vascular relaxation.

抄録全体を表示

The objective of this study was to determine the pumping capability of dynamic cardiomyoplasty during induced ventricular fibrillation. In this acute study of 6 dogs, the pumping capability of the unconditioned left latissimus dorsi (LD) muscle (141 to 292gm), wrapped around both ventricles, was investigated during induced ventricular fibrillation. Left-ventricular and femoral artery pressure, the ECG and aortic root flow velocity were monitored. Prior to inducing ventricular fibrillation, the ability of the unconditioned LD muscle to augment stroke volume (SV), was quantified as the area under the aortic flowvelocity record. The ventricles were then fibrillated and, after 10sec, rhythmic 250msec trains (1/sec) of stimuli (40/sec) were delivered to the thoracodorsal nerve to contract the LD muscle tetanically. In no case could dynamic cardiomyoplasty produce the same SV as when the ventricles were beating normally. In one animal, the SV attained two percent of the normal SV by 5 contractions; in another, the SV reached one percent by 25 contractions. In the remaining animals, the SV varied around 20% of the prefibrillation SV. By 90 contractions, the stroke volume was 10% of the prefibrillation value. The progressive decrease in SV was likely a consequence of LD muscle ischemia and fatigue, since the latissimus dorsi muscle provided low blood flow during the period of fibrillation.

抄録全体を表示

We observed a case of acute myocardial infarction induced by second diagonal branch occlusion. Electrocardiogram (ECG) on admission showed ST elevation in leads I, aV_L and V_2-6. Since emergency coronary angiography disclosed complete occlusion of the second diagonal branch, intra-coronary thrombolysis (ICT) was performed, superselectively. Transient coronary reperfusion was obtained, however, reocclusion occurred after several minutes. Rescue percutaneous transluminal coronary angioplasty (PTCA) was then performed immediately and blood flow was improved to TIMI grade 2. During these processes, the ST-segment on the ECG changed in leads I, aV_L and V_2-6 always corresponding to the blood flow of the second diagonal branch.
We have not seen a report hitherto in which occlusion of only the second diagonal branch could be a cause of extensive anterior infarction-like ECG changes. Although the mechanism of ECG changes in this patient cannot be clearly explained by conventional concepts, we report this case because it is considered to be very rare.

抄録全体を表示

A 53-year-old female presented with symptoms of severe chest and back pain associated with oliguria. The patient had a history of exertional dyspnea since the age of 20, and easy fatigability since the age of 27. At the age of 41, she noted marked exacerbation of these symptoms after suffering from a cold and was ultimately diagnosed as having Bland-White-Garland (BWG) syndrome with mitral valve regurgitation. The patient then underwent re-implantation of an anomalous left coronary artery from the pulmonary artery to the posterolateral wall of the aorta. Eleven years later, she re-presented with symptoms of angina and congestive heart failure. Coronary angiography was subsequently performed and a total occlusion of the right coronary artery with probable thrombus was revealed. The right coronary artery was filled via collaterals from the implanted left coronary artery. Mitral regurgitation was noted during angiography. The patient underwent aorto-coronary artery bypass grafting of the right coronary artery and concomitant mitral valve replacement. Her postoperative condition remained excellent.

抄録全体を表示

Myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM) may play an important role in the function and/or dimensions of the left ventricle. We present an autopsied case of HCM followed for 10 years. A 68-year-woman with HCM underwent trans-aortic myectomy of the interventricular septum in 1979. A significant amount of round cell infiltration, myocardial fibrosis and disarray were observed in the resected specimen. She experienced repeated admissions due to diabetes mellitus and congestive heart failure, and died of renal failure in 1989. An autopsy revealed extensive myocardial fibrosis and significant cell infiltration in the ventricular myocardium. The infiltrating cells were almost all lymphocytes, and the ratio of CD4 to CD8 was 3.8. This ratio was different from that of typical viral myocarditis. This case suggests that there may be an undefined inflammatory process causing fibrosis in HCM, in addition to the ischemia due to intramural small coronary artery stenosis.

抄録全体を表示

We describe a patient with an infected right atrial thrombus and pulmonary embolism who died suddenly. Jejunal diverticulitis, which was found at autopsy, was suspected to be the source of the bacterial thrombus. The 41-yearold female patient was admitted because of dyspnea and syncopal attacks. Physical examination on admission revealed an obese woman with a body temperature of 36.5°C, systolic heart murmur and abnormal diastolic heart sound. Two-dimensional echocardiography revealed a strand-shaped mass in the right atrium. Lung blood perfusion scintigraphy revealed multiple perfusion defects in both lung fields. She suddenly developed severe dyspnea leading to death on the 6th hospital day. At autopsy, a strand-shaped organized thrombus was found in the right cardiac chambers. Microscopically, the thrombus was found to be infiltrated with numerous gram-positive cocci, leukocytes and a small number of gram-negative cocci. Most of the major pulmonary arterial branches were occluded by bacterial thromboemboli, and multiple pulmonary infarctions were found in both lungs. A perforating diverticulum with microabscess was found in the jejunal mucosa which was assumed to be the source of the bacterial thromboembolism.

抄録全体を表示

We report a case of malignant lymphoma whose initial symptoms were heart failure. An echocardiogram showed a large tumor in the right ventricle, and a definitive diagnosis was obtained at autopsy. Of particular interest in our case, the lymphoma was confined to the heart and a mediastinal lymph node, with its greatest bulk being intracardiac. This case is a rare manifestation of malignant lymphoma.

抄録全体を表示

A case of intrapericardial pheochromocytoma which secreted predominantly norepinephrine is reported. A tumor at the posterior wall of the left atrium was demonstrated by computed tomographic and magnetic resonance imaging scan. Tumor blush arising from the left circumflex branch was visualized by coronary angiography. The tumor (4×3.5×2cm) was resected with adherent atrial wall and the defect reconstructed with the patients own pericardium under general anesthesia with artificial cardiopulmonary bypass. His subsequent postoperative recovery was uneventful. At the time of discharge, 8 weeks after operation, his blood pressure and plasma norepinephrine remained normal. The value of magnetic resonance imaging scan for the topographic diagnosis of cardiac pheochromocytoma is emphasized.

抄録全体を表示