Radiofrequency catheter ablation (RFCA) targeting the cavotricuspid isthmus is usually an effective treatment for common atrial flutter (AFL), except in a small subset of patients and the reason for this has yet to be elucidated. The present study investigated the relationship between the outcome of RFCA for common AFL and the anatomy of the right atrium as seen on angiography. Twenty consecutive patients who underwent RFCA for common AFL were divided into 2 groups according to the results of RFCA. Group A comprised 13 patients whose AFL was abolished, fulfilling the criteria of success by the conventional catheter approach, and group B comprised 7 patients whose AFL could not be abolished according to the criteria for success (n=4) or was abolished following an additional superior vena cava approach (n=3). On angiography, the cavotricuspid isthmus was longer (3.5±0.5 vs 2.2±0.6cm) and deeper (0.94±0.35 vs 0.49±0.19cm) in group B than in group A (both p<0.01). The height of the eustachian valve was also greater in group B than in group A (1.4±1.1 vs 0.48±0.48cm, p<0.02). These results suggest that the anatomical structure of the cavotricuspid isthmus affects the outcome of RFCA for common AFL.

View full abstract

The present study investigated the relationship between aortic atherosclerosis and carotid atherosclerosis, and studied the effects of coronary risk factors for these arteries. The subjects consisted of 78 patients with coronary artery disease (CAD) and 69 patients without CAD. All subjects underwent enhanced computed tomography and B-mode ultrasonography within a short time period to determine the extent of aorta and carotid atherosclerosis. Significant correlations between maximal aortic wall thickness (MAWT) and aortic wall volume (AWV) with carotid intima-media thickness (IMT) were demonstrated. MAWT, AWV and IMT were significantly higher in patients with CAD compared with controls (p=0.009, p=0.024, p=0.001, respectively). Furthermore, there were significant differences in MAWT, AWV and IMT among groups classified by the number of coronary artery stenoses, and no significant differences among groups classified by risk factors, but it was shown that MAWT. AWV and IMT increased gradually as the risk factors increased in number. MAWT, AWV and IMT had positive correlations with age, systolic blood pressure and triglyceride, and a negative correlation with high density lipoprotein-cholesterol. This study demonstrated that both aortic atherosclerosis and carotid atherosclerosis are closely correlated with coronary atherosclerosis, and that the atherosclerosis indices are independently associated with age and hyperlipidemia.

View full abstract

A single oral dose of pilsicainide, a class 1c antiarrhythmic drug, is effective in terminating acute-onset atrial fibrillation (AF), but its effect on pacing thresholds in pacemaker patients is unknown. The present study measured atrial and ventricular pacing thresholds after a single oral dose of pilsicainide in patients with and without AF. Twelve patients with dual-chamber pacemakers were evaluated. Pacing thresholds as well as plasma pilsicainide concentration were measured prior to and then at 30, 60, 90, 120 and 180 min and 24h following a single oral dose of pilsicainide (150mg). Six patients had paroxysmal AF and the remaining 6 did not. Pacing thresholds increased significantly (134±8%) in the atrium (p<0.05) and in the ventricle (155±11%; p<0.001) following pilsicainide administration in all 12 patients. Plasma concentrations of pilsicainide showed a positive liner correlation with pacing thresholds (R=0.62, p<0.0001 in the atrium; R=0.74, p<0.0001 in the ventricle). Atrial pacing thresholds in the patients with AF showed a significant increase at 90, 120 and 180 min compared with the patients without AF (p<0.05). There was no significant difference in either the ventricular pacing threshold or the plasma pilsicainide concentration in the patients with and without AF. It was concluded that a single oral dose of pilsicainide increases the pacing thresholds in both the atrium and ventricle in a selected group of pacemaker-implanted patients; that is, those who are aged and with AF. Thus, careful attention should be paid to pacemaker-dependent patients, particularly those with paroxysmal AF, when administering pilsicainide.

View full abstract

Cardiac involvement is the major determinant of morbidity and mortality in patients with sarcoidosis, but clinical evaluation of the disease activity is occasionally difficult in cardiac sarcoidosis. The present study examined whether serum levels of interleukin-10 (IL-10) could reflect the disease activity of patients with cardiac sarcoidosis. Serum IL-10 levels were measured using an enzyme-linked immunosorbent assay, and compared with clinical manifestation, levels of angiotensin-converting enzyme (ACE), levels of lysozyme and accumulation of gallium-67 citrate. Sera were collected from 8 patients with cardiac sarcoidosis (CS group), 22 patients with miscellaneous heart diseases except for sarcoidosis (MHD group), and 8 healthy control subjects (HC group). Serum IL-10 levels of the CS group were significantly higher than those of the 2 control groups. Before steroid therapy, the levels of IL-10 in the CS group showed a significantly positive correlation with levels of ACE (r=0.868, p<0.05) and lysozyme (r=0.890, p<0.05). In 5 patients who were analyzed before and after steroid therapy, the levels of IL-10 tended to correlate with a decrease of an abnormal accumulation in gallium-67 citrate. Serum IL-10 levels may play a role in evaluation of the disease activity in patients with cardiac sarcoidosis.

View full abstract

In 21 patients with chronic aortic dissections and proven patent false lumens, the flow volume and flow patterns in the patent false lumens was evaluated using velocity-encoded cine magnetic resonance imaging (VENC-MRI) and the relationship between the flow characteristics and aortic enlargement was retrospectively examined. Flow patterns in the false lumen were divided into 3 groups: pattern A with primarily antegrade flow (n=6), pattern R with primarily retrograde flow (n=3), and pattern B with bidirectional flow (n=12). In group A, the rate of flow volume in the false lumen compared to the total flow volume in true and false lumens (%TFV) and the average rate of enlargement of the maximum diameter of the dissected aorta per year (ΔD) were significantly greater than in groups R and B (%TFV: 74.1±0.07 vs 15.2±0.03 vs 11.8±0.04, p<0.01; ΔD: 3.62±0.82 vs 0 vs 0.58±0.15 mm/year, p<0.05, respectively). There was a significant correlation between %TFV and ΔD (r=0.79, p<0.0001). Evaluation of flow volume and flow patterns in the patent false lumen using VENC-MRI may be useful for predicting enlargement of the dissected aorta.

View full abstract

To determine changes in plasma brain natriuretic peptide (BNP) after direct current cardioversion (DC) and to evaluate the relationship between plasma atrial natriuretic peptide (ANP) and BNP and the recurrence of atrial fibrillation (AF) after DC in patients with mild congestive heart failure (CHF), plasma ANP and BNP were measured before and after DC in 71 patients with mild CHF and then followed. In 65 patients with successful DC, both ANP and BNP decreased 15 min after DC. Cox stepwise multivariate analysis among 14 variables such as age, history of AF, echocardiographic parameters, medication and ANP and BNP revealed that only low ANP (p=0.005) and high BNP before DC (p=0.0002) were independent predictors of recurrent AF. A ratio of ANP to BNP less than 0.44 was a significant risk factor for AF recurrence by Kaplan-Meier analysis (p=0.02). BNP began to decrease immediately after successful DC. High BNP and relatively low ANP compared with BNP were independent risk factors of AF recurrence in patients with mild CHF.

View full abstract

The effect of a novel cardioprotective agent, JTV-519 on myocardial metabolism and contraction during ischemia and reperfusion was investigated by means of phosphorus 31-nuclear magnetic resonance (³¹P-NMR) in Langendorff rabbit hearts. Normothermic, 20-min, global ischemia was followed by 30min of postischemic reperfusion and JTV-519 was administered from 40min prior to the global ischemia. Adenosine triphosphate (ATP), creatine phosphate (PCr), inorganic phosphate (Pi), intracellular pH (pHi), left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP) and coronary flow were measured. Fourteen hearts were divided into 2 experimental groups of 7: Group I were controls and Group II were perfused with JTV-519 (10^-6mol/L). During ischemia, Group II showed a significant (p<0.01) inhibition of the increase in Pi and LVEDP and the decrease in ATP and pHi, compared with Group I. After postischemic reperfusion, Group II also showed a significant (p<0.01) improvement in ATP and pHi as compared with Group I. There were no differences in LVDP or coronary flow during ischemia and reperfusion between the 2 groups. In conclusion, JTV-519 had a significant beneficial effect on myocardial energy metabolism and relaxation during both myocardial ischemia and reperfusion.

View full abstract

The cardiovascular profile of verapamil was assessed in the halothane-anesthetized canine model and compared with that of propranolol. Verapamil was infused at the rates of 1, 3 and 10μg·kg^-1·min^-1 (n=6), whereas propranolol was administered at a fixed rate of 10μg·kg^-1·min^-1 (n=6). Each infusion was performed over 30min, and the parameters were assessed for 20-30min after the start of each infusion. Verapamil in a dose of 10μg·kg^-1·min^-1 significantly suppressed atrio-ventricular (AV) node conduction and slightly decreased the mean blood pressure, but no significant change was detected in the left ventricular end-diastolic pressure, maximum upstroke velocity of the left ventricular pressure, sinus automaticity, double product, cardiac output, intraventricular conduction, and ventricular repolarization phase and refractoriness. Propranolol suppressed AV node conduction to an extent similar to that of verapamil, but it also inhibited intraventricular conduction, sinus automaticity and ventricular contraction, increased the ventricular refractoriness, and decreased the double product and cardiac output, without any significant change in the other variables measured. These results suggest that verapamil can selectively affect the AV node, and that the greater part of the suppressive action of propranolol on the multiple cardiovascular performance is through a β-blocking action and direct membrane effect, although the halothane inhalation itself might have modified each of the drug’s effects. The abbreviation of the relative refractory period of the ventricle by propranolol may show its potential utility for re-entry type ventricular tachycardia.

View full abstract

A 57-year-old man with dyspnea and dry cough exhibited pulmonary embolism. Pulmonary arteriography demonstrated absent perfusion of the left main and the right upper and middle lobe pulmonary arteries. A diagnosis of chronic pulmonary thromboembolism was assumed and surgical thromboendarterectomy was attempted under standard cardiopulmonary bypass. At operation, a tumor had invaded far into both the right and left pulmonary arteries and radical resection was impossible. The final pathological diagnosis was primary leiomyosarcoma of the pulmonary artery. The patient refused any adjuvant therapy and died 63 days after the surgery. The clinical presentation of this case was similar to that of pulmonary thromboembolism and its diagnosis and treatment were very difficult.

View full abstract

A 52-year-old man with pheochromocytoma had cardiogenic shock and was rescued using a percutaneous cardiopulmonary supporting system. After recovery, diagnostic tests including metaiodobenzylguanidine scintigraphy and computed tomography, revealed the pheochromocytoma which was confirmed by histology. It was postulated that the acute episode was induced by intra-joint dexamethasone, which increased the production of epinephrine and augmented the sensitivity of cardiomyocytes for catecholamine, thereby inducing the cardiomyopathy.

View full abstract

Acute reversible left ventricular wall motion abnormalities mimicking myocardial stunning have been reported with noncardiac disease and their coronary angiograms did not demonstrate organic stenosis or vasospasm in the epicardial coronary arteries. Thus, this mechanism has not yet been fully clarified. Two patients are reported as demonstrating acute reversible wall motion abnormalities after noncardiac disease. The electrocardiographic and echocardiographic findings mimicked myocardial stunning and confirmed the previous reports. The coronary angiograms did not show any corresponding coronary stenosis or vasospasm, but did show a reduced coronary flow reserve. Cardiac metaiodobenzylguanidine scintigraphy demonstrated regional defects involving the apex, a decreased heart/mediastinum ratio and an enhanced washout rate, which partially returned to normal after 3 months. Microvascular dysfunction and sympathetic nervous abnormalities might be responsible for the reversible contractile impairment.

View full abstract

A curious retrograde conduction in connection with the coronary sinus (CS) musculature was observed in 2 patients. After the failed ablation procedure, the atrial electrogram during ventricular pacing presented double potentials, the first component of which was sharp and with an activation sequence that was the same before ablation (CS distal to proximal). The second component of the double potentials was dull and had a decremental property; its activation sequence was in reverse (proximal to distal). In both cases, the first component disappeared after successful ablation. These findings suggest that the first component was the CS electrogram conducted over the accessory pathway and the second component was the left atrial electrogram conducted through the inter-atrial septum. The separation of each electrogram is probably the result of a block between the accessory pathway connected to the CS musculature and the left atrium. These are unusual cases of an accessory pathway connected to the CS musculature, which separates the left atrial myocardium at the distal portion from the ostium.

View full abstract

A patient with a thrombosed mechanical valve underwent valve re-replacement during which a tumor of the left ventricular outflow tract with the typical macroscopic and microscopic characteristics of a papillary fibroelastoma was successfully removed surgically. The 60-year-old woman had undergone isolated mitral valve replacement with a St Jude Medical 29-mm valve for mitral regurgitation 15 years ago. The present admission was for investigation of dyspnea on exertion. Two-dimensional transthoracic echocardiography demonstrated a posteroseptal, pedunculated mass, measuring 1.3×1.0cm, in the outflow tract of the left ventricle, mild mitral regurgitation and slight aortic stenosis.

View full abstract

A very short coronary stenosis is somewhat difficult to correctly evaluate by conventional coronary angiography. The demonstration of positive and negative contrast jets observed just distal to the lesion is helpful in identifying the severity of the disease causing this disorder. In the present case, intravascular ultrasound confirmed the presence of a very short stenosis and membranous disease at the site of the lesion. The presence of intracoronary contrast jets reflects the morphology and severity of disease of the membranous type, although the reason for the appearance of contrast jets with this type of lesion should be sought.

View full abstract

Septal perforator arteries play an important role in the blood supply of the anterior interventricular septum. Their intramyocardial course makes them inaccessible for coronary bypass revascularization. Although modern catheter-based techniques might be superior to coronary bypass grafting in offering the most complete revascularization in selected patient populations, a systematic review of the literature revealed a paucity of data regarding the outcome of these patients. The present report describes coronary stent implantation in a dominant septal perforator artery and the analysis of the anatomic relationship between the stent and the intraventricular septum using a new imaging technique, catheter-based intracardiac ultrasound.

View full abstract

A new enzyme-linked immunosorbent assay can detect 10pg/ml of human hepatocyte growth factor (HGF). Circulating HGF was significantly higher in patients with unstable angina (296±184pg/ml, mean±SD, n=36) than in healthy volunteers (201±64pg/ml, n=250, p<0.0001). Individual concentrations exceeded the mean control value +2 SD (329pg/ml) in 12 of the 36 (33%) patients with unstable angina. The present study indicates that this new, sensitive HGF assay can successfully detect thrombosis in patients with unstable angina.

View full abstract