Japanese heart journal最新文献

This study was designed to evaluate the possible in vivo induction of DNA damage by exposure to radiation in cardiologists. The alkaline comet assay (single cell gel electrophoresis, SCGE), which appears to be a promising tool with which to estimate DNA damage at the single cell level, has been used. The assay was carried out on 30 cardiologists currently employed in a busy cardiac service and 30 healthy unexposed controls. Venous blood samples were obtained from the exposed and control subjects and SCGE was examined in 100 cells graded as undamaged, intermediate, and tailed nuclei. The number of undamaged nuclei was almost the same in control and exposed subjects. The extent of DNA migration (SCGE assay) did not distinguish between the samples in either the nonsmoker exposed or nonsmoker control subjects, which leads one to wonder whether a difference in DNA damage really exists. Previous studies reported increased DNA damage in blood lymphocytes of smokers. In our study, the percentage of damaged cells increased either with the frequency of smoking or exposure to radiation. A statistically significant difference was observed both in smokers and exposed subjects. In conclusion, the elevated grade of DNA damage in cardiologists exposed to radiation indicates a possible genotoxic hazard, therefore, careful measures and full cooperation between cardiologists and radiologists should be undertaken to reduce the exposure to radiation.

The aim of the present study was to investigate the adverse effects of hypertension on the cardiovascular system in daily activities and the effect of acute blood pressure reduction on oxygen (O(2)) uptake kinetics. Twenty hypertensive patients were included in the study group. Patients performed treadmill exercise tests (2.5 km/hour and 5 inclines) twice, before and after blood pressure reduction with sublingual captopril. In the control group, ten hypertensive patients underwent two tests one hour apart without blood pressure reduction brought about by drug therapy. The changes in O(2) kinetic values (O(2) deficit and mean response time [MRT]) between the two tests were investigated. In the study group, the O(2) deficit and MRT values measured during the first exercise testing were found to be 547 +/- 183 mL and 40 +/- 9 seconds, while those in the second exercise testing were 401 +/- 127 mL and 34 +/- 7 seconds, respectively. In the control group, the O(2) deficit and MRT values measured during the first exercise test were 491 +/- 217 mL and 42 +/- 16 seconds and 515 +/- 159 mL and 41 +/- 13 seconds in the second exercise test. The differences in O(2) deficit and MRT in the study group were considered to be statistically significant (P = 0.008 and P = 0.004, respectively). Based on our findings, there was a significant improvement in O(2) kinetic values with an acute reduction in blood pressure in hypertensive patients, most likely as a result of an improved response in cardiac output.

The identification of risk factors for the initiation of left ventricle hypertrophy (LVH), which is an independent risk factor for cardiovascular mortality and morbidity in hypertensive patients, is very important. The objective of the present study was to identify the relationship of aldosterone with LVH and different geometrical patterns of left ventricle that develop in patients with essential hypertension. A total of 83 patients with essential hypertension (44 females, mean age, 51 +/- 8 years, 39 males, mean age, 57 +/- 10 years) were included in this study. Thirty-two had LVH. When evaluated according to the geometrical patterns of LVH, 18 patients had concentric LVH, 14 had eccentric LVH, and 17 had concentric remodeling. Thirty-four patients had normal left ventricle geometry. Two weeks after the cessation of antihypertensive medications, sodium, potassium, and proteinuria in 24-hour urine samples and plasma aldosterone levels and plasma renin activity were measured. Plasma aldosterone levels of the patients with LVH were found to be significantly higher (9.92 +/- 6.34 ng/dL versus 5.83 +/- 3.5 ng/dL, P < 0.01). The difference between plasma renin activities was not statistically significant. Linear regression analysis revealed that plasma aldosterone level and age were independent parameters increasing left ventricle mass index. The plasma aldosterone levels of patients with concentric hypertrophy of the left ventricle were significantly higher than those of patients with normal geometry and concentric remodeling. There was no significant difference between plasma renin activities. Twenty-four hour urine protein concentrations of the patients with LVH were found to be significantly higher and sodium to be significantly lower. Plasma aldosterone levels seem to be correlated with LVH especially with concentric hypertrophy of the left ventricle in patients with essential hypertension.

Systemic thromboembolism is a major complication of mitral stenosis (MS), especially in those patients having atrial fibrillation (AF). Recent evidence has suggested that regional left atrial coagulation activity may be increased in MS and may contribute to the pathophysiology of left atrial thrombus. However, the relation of left atrial coagulation activity to factors that predispose to left atrial thrombus formation is unknown. Also, the relations between left atrial and systemic coagulation activity, fibrinolysis, and platelet activation remain unresolved. Left atrial and peripheral venous levels of fibrinogen, antithrombin III, factor VII and factor VIII for coagulation, D-dimer, tPA and PAI-I, plasmin and antiplasmin for fibrinolysis, and platelet factor 4 and vWF for platelet activation, and endothelial dysfunction were measured in 46 patients with MS and normal clotting times who were undergoing percutaneous mitral valvuloplasty. Left atrial tPA, plasmin, PAI-I, antiplasmin, PF4, and vWF levels exceeded the corresponding peripheral venous levels (P < 0.05) in patients with MS, being more significant in the AF subgroup. There were no significant differences between left atrial and peripheral venous levels of fibrinogen, D-dimer, factor VII, and factor VIII within the patient group (P > 0.05). The results suggest that there are significant variations in the indices of coagulation, fibrinolytic system and platelet activation, and endothelial dysfunction between left atrial and peripheral venous blood samples of patients with MS that may be due to limited spillover from the left atrium to the systemic circulation.

We conducted a questionnaire survey regarding quality of life (QOL) to evaluate the effects of exercise training on the QOL in patients with valvular heart disease after surgery. This study included 64 consecutive patients who underwent heart surgery. They were divided into two groups: exercise training could (EX(+) group, n = 31) and could not be performed (EX(-) group, n = 33) until 6 months after surgery. To evaluate the QOL and exercise tolerance, we employed "a questionnaire regarding disease and quality of life" developed for Japanese people and cardiopulmonary exercise testing. In our questionnaire survey, the improvement rating (Delta subjective/social index), which was calculated from the difference between the pre-and postoperative values, was greater in the EX(+) group than that in the EX(-) group (4.9 +/- 3.1 versus 1.1 +/- 4.0, P < 0.05). In the changes in exercise tolerance, Delta anaerobic threshold was greater in the EX(+) group (0.79 +/- 0.17 versus -0.02 +/- 0.28, P < 0.01). Moreover, there was a positive correlation between Delta subjective/social index and Delta peak VO(2) (r = 0.62, P < 0.05). We concluded that exercise training for patients after cardiac surgery improves the QOL and exercise tolerance. It is suggested that changes in subjective and social parameters contribute to an exercise training-related improvement in the QOL.

We conducted this study to verify the efficacy of ventricular unipolar potential (V-uni) for ablation of idiopathic non-reentrant ventricular tachycardia (idio-VT). The morphology of V-uni at the successful and unsuccessful sites was analyzed in 27 patients with idio-VT [20 with right ventricular outflow tachycardia (RVOVT) and 7 with left ventricular outflow tachycardia (LVOVT)]. The usefulness of V-uni was compared with a pacemapping method and the V-QRS interval. The incidence of QS-pattern V-uni at the successful and best unsuccessful sites were 100 versus 25% (P = 0.000005) in RVOVT and 86 versus 29% (P = 0.10) in LVOVT. The pacemapping scores at the successful and best unsuccessful sites were 11.5/12 versus 11.2/12; NS in RVOVT, and 11.2/12 versus 11.1/12; NS in LVOVT. The mean V-QRS interval at the successful and the best unsuccessful sites were 22.5 +/- 3.8 versus 21.6 +/- 3.4 msec; NS in RVOVT, 15.1 +/- 3.2 versus 12.5 +/- 3.3 msec; NS in LVOVT. The sensitivity (sen) and specificity (spe) of QS-pattern V-uni to determine the optimum target sites were 1.0 and 0.89 in RVOVT and 0.86 and 0.83 in LVOVT, respectively. In the ablation of idio-VT, QS-pattern V-uni is simply and visually identifiable, is very useful, and should be given a high priority when determining the optimum target site.

In this report, we describe three patients with acute myocardial infarction due to coronary embolism who were successfully treated using a thrombus aspiration device. Thrombus aspiration is shown to be a feasible and effective strategy for the treatment of acute coronary embolism.

Myocardial stunning with hyperthyroidism is rare. A 79-year old woman with hyperthyroidism was admitted to our hospital complaining of palpitations due to paroxysmal atrial fibrillation. An echocardiogram showed akinesis of the apical wall which was not observed 2 weeks before admission. Cardiac catheterization performed in the acute phase showed normal coronary arteries and no evidence of provocative spasms. The wall motion abnormality disappeared entirely after 1 week in hospital. We report a case of transient left ventricular dysfunction, so called "takotsubo" cardiomyopathy, associated with hyperthyroidism.

We previously demonstrated that the severity of arrhythmias is reflected by circulating brain natriuretic peptide (BNP) concentrations in patients without signs of congestive heart failure. In the present study, we evaluated the relationships between the severity of the arrhythmia, BNP concentration, and echocardiographic findings. The subjects consisted of 52 patients with ventricular premature contractions (VPC) but no manifestations of heart failure and no digoxin or beta-blocker therapy. Patients underwent Holter monitoring, plasma sampling for BNP measurement, and transthoracic echocardiography (TTE). We scored the motion of 16 left ventricular segments, deriving a wall-motion score index (WMSI) by totaling the scores and dividing by the number of segments scored. Twenty-three patients with Lown grade I to II arrhythmias constituted group A while group B consisted of 29 Lown III to IV patients. Group B had BNP concentrations triple those in group A (57.2 versus 18.1 pg/mL, P < 0.01). Left ventricular ejection fraction (LVEF) was similar in groups A and B (65.2% versus 62.1%, NS). Although left ventricular end-diastolic dimension (LVEDD) was normal in both groups, group B exhibited a larger LVEDD than group A (50 versus 46 mm, P < 0.005). The correlation (r) between BNP and interventricular septum thickness (IVST) was 0.27 (P = 0.013) in group A and 0.37 (P < 0.0001) in group B. Between BNP and posterior wall thickness (PWT), the correlation was 0.23 (P = 0.014) in group A versus 0.33 (P < 0.0001) in group B. The WMSI in group B was higher than in group A (1.34 versus 1.11, P < 0.05). We believe that besides the changes in echocardiographic parameters, the BNP elevation in group B could be a response to abnormal wall stress from the severe ventricular arrhythmias.

Carverdilol has a variable outcome in treating patients with chronic heart failure. This prospective single-center study evaluated the predictors of clinical variables in determining favorable outcomes in treating chronic heart failure patients with carvedilol. The relation between clinical variables and maintenance doses of carvedilol was also determined. Seventy chronic heart failure patients (mean age, 62.2 years, 50 males and 20 females) with a left ventricular ejection fraction < 35% and functional class II-III were enrolled in the study. The patients were clinically followed-up for at least 24 months. Patients were considered to have a favorable outcome if they had no decreases in functional class or quality-of-life score, an increase in left ventricular ejection fraction>5%, were not admitted to hospital due to worsening heart failure, and free of cardiac mortality. Patients with favorable outcomes had a younger age (P = 0.021), higher baseline systolic blood pressure (P = 0.080), better baseline functional class (P = 0.001), and a higher tolerated dose of carvedilol (P = 0.026) than those in the unfavorable group. In this primarily Chinese cohort of chronic heart failure patients, those with favorable outcomes were likely to be young, have a high baseline systolic blood pressure, and good baseline functional class.