Hiroshi Yamanari

Early Afterdepolarization Abolished by Potassium Channel Opener in a Patient with Idiopathic Long QT Syndrome

Abolished Early Afterdepolarization by Nicorandil. We describe a 17‐year‐old boy with idiopathic long QT syndrome and repeated syncopal episodes. Early afterdepolarization (EAD) in the monophasic action potential (MAP) was demonstrated in the posterior septum of the left ventricle. Injection of the potassium channel opener nicorandil decreased KAD and shortened MAP duration. The syncopal episodes due to ventricular fibrillation disappeared after administration of the potassium channel opener.

Dispersion of regional wall motion abnormality in patients with long QT syndrome

Objective To examine the left ventricular regional wall motion abnormality and to evaluate dispersion of this abnormality in patients with long QT syndrome. Design Left ventricular short axis images at basal and middle levels were recorded on videotape and digitised to reconstruct digitised M mode echocardiograms, from which left ventricular wall thickness curves were obtained. The wall thickening time (ThT) was defined as the period in which the instantaneous wall thickness exceeded 90% of the maximum wall thickness. ThT was measured at three segments in each of the septal and free wall sides of the left ventricle, a total of 12 segments. To examine the mechanical dispersion of the left ventricle, the difference between the maximum and minimum ThT of 12 segments in each subject was obtained. Patients Eight patients with congenital long QT syndrome (averaged QTc interval (SD) 509 (27) ms1/2) and 10 control subjects (QTc interval 397 (26) ms1/2) were examined. Results The averaged ThT values of the 12 segments pooled from all subjects were correlated with the QT intervals (r = 0.72, p < 0.005). Thus the averaged ThT in the long QT syndrome patients was longer than in the control subjects (p < 0.005). The segmental variation of ThT in the patients was greater than in the control subjects (p < 0.001). The dispersion of ThT in the patients was therefore larger than in control subjects (p < 0.005). However, the pattern of ThT variation in the patients varied according to the individual subject. Conclusions There is not only electrical but also mechanical dispersion in the left ventricle of long QT syndrome patients. Regional assessment of ventricular wall motion may allow quantification of the spatial variation of wall motion abnormality.

Effects of oral theophylline on sick sinus syndrome

OBJECTIVES We sought to determine the effect of theophylline on cardiac pauses in sick sinus syndrome. BACKGROUND Sick sinus syndrome, a relatively benign condition, is usually treated with pacemaker implantation without any proved effectiveness. Thus, an appropriate pharmacologic therapy would be useful. METHODS Theophylline (200 to 400 mg/day for 1 month) was initially administered orally to 17 patients with sick sinus syndrome, which is manifested by sinus pauses of > 2.5 s. Eleven of the 17 patients subsequently received theophylline for an additional 8 to 37 months. Twenty-four-hour Holter recordings were obtained before treatment, at the end of 1 month of treatment and then at 6-month intervals. RESULTS Theophylline decreased the frequency of sinus pauses from 256 +/- 230 to 23 +/- 62 pauses per 24 h and decreased the duration of the longest pauses from 4.7 +/- 1.8 to 2.2 +/- 0.97 s after 1 month of treatment. Subjective symptoms associated with cardiac pauses disappeared in 16 of 17 patients. Ventricular premature beats increased in frequency but did not last longer than two beats. Three patients experienced adverse effects. Nine of the 11 patients receiving long-term treatment had a good outcome, but 2 patients required a pacemaker because of the reappearance of long sinus pauses. CONCLUSIONS The results suggest that oral theophylline may be beneficial for the treatment of patients with sick sinus syndrome.

Papillary fibroelastoma in the left ventricular outflow tract.

SummaryWe report a case of a papillary fibroelastoma originating from the left ventricular endocardium in the outflow tract which was discovered by echocardiography in an asymptomatic patient. Two echocardiographic features were observed: (1) the tumor surface was smooth, and characteristic papillary formation was not detected; and (2) the outline of the mass was clearly defined as a dense echo, with the central, radiolucent, portion surrounded by a highly refractive linear echo at the level of the maximum diameter of the mass. The excised tumor was covered with a gelatinous substance that masked multiple papillae on the surface, but its echolucent center could not be explained by the pathology of the tumor which was solid centrally. Our case indicates that a papillary fibroelastoma may sometimes show echocardiographic findings similar to those of a myxoma, although other investigators have not noted the smooth surface and the echolucent center makes it indistinguishable from a myxoma. Thus, in some cases, it is difficult to distinguish papillary fibroelastoma from myxoma by echocardiography.

Effects of cardiac sympathetic innervation on regional wall motion abnormality in patients with long QT syndrome

AIM To assess the spatial relation between regional cardiac sympathetic innervation and regional ventricular repolarisation indicated by ventricular wall motion abnormality in patients with congenital long QT syndrome. DESIGN Regional percentage uptake and washout rate of123I metaiodobenzylguanidine (MIBG) were measured to assess cardiac sympathetic innervation in septum, anterior wall, lateral wall, and posterior wall. Left ventricular short axis images on echocardiography were digitised to reconstruct digitised M mode echocardiograms, from which left ventricular wall thickness curves were obtained. The wall thickening time (ThT) was defined as the period in which the instantaneous wall thickness exceeded 90% of the maximum wall thickness. The ThT was measured from the ventricular wall thickness curve at the same segments where regional percentage uptake and washout rate of 123I MIBG were measured. PATIENTS Seven patients with long QT syndrome. RESULTS The regional washout rate (mean (SD)) of123I MIBG in patients with long QT syndrome was greater in the segments with decreased percentage uptake of 123I MIBG than in those without (17.4 (10.6)% v 9.7 (16.5)%, p < 0.03). ThT in segments both with and without decreased percentage uptake of 123I MIBG was longer than in control subjects (p < 0.0001). ThT was longer in the segments with decreased percentage uptake of 123I MIBG than in those without (199 (70) ms v 150 (66) ms, p = 0.0018). CONCLUSIONS Activation of regional cardiac sympathetic terminals is likely to participate in additional regional prolongation of ventricular repolarisation in patients with long QT syndrome.

Effect of regional myocardial perfusion abnormalities on regional myocardial early diastolic function in patients with hypertrophic cardiomyopathy

SummaryNonuniform hypertrophy of the left ventricle is an important factor in regional diastolic dysfunction in patients with hypertrophic cardiomyopathy (HCM). However, the effect of myocardial perfusion abnormalities on regional diastolic dysfunction has not been established in patients with HCM. We investigated the relationship between regional myocardial perfusion abnormalities and regional early diastolic function in 31 patients with HCM and 8 control patients. Short-axis images of the left ventricle recorded by cine magnetic resonance imaging were divided into ten blocks. The time-to-peak-wall-thickness-thinning rate (TPWR) and the wall thickness were measured in each block. Of the 310 blocks from the patients with HCM, 242 (78%) showed normal thallium-201 uptake (group 1), 40 (13%) showed slightly decreased uptake (group 2), and 28 (9%) showed markedly decreased uptake (group 3). There was no difference in the regional wall thickness among the three groups. The TPWR was longer in patients with HCM than in control patients. It was significantly longer in group 3 (190±45ms) than in group 1 (167±36ms) and group 2 (160±31ms). (P<0.01). The linear regression slope of the relationship between the TPWR and the regional wall thickness was significantly steeper in group 3 than in groups 1 and 2 (P<0.05). In conclusion, abnormalities in regional myocardial perfusion, in addition to regional hypertrophy, contributed to the regional early diastolic dysfunction in patients with HCM.

Spironolactone and Chlorthalidone in Uncontrolled Elderly Hypertensive Patients Treated with Calcium Antagonists and Angiotensin II Receptor-Blocker: Effects on Endothelial Function, Inflammation, and Oxidative Stress

The side effects of thiazide-type diuretics include metabolic abnormality and increased oxidative stress, which might cause endothelial dysfunction despite blood pressure reduction. In hypertensive patients with heart failure, treatment with an aldosterone antagonist resulted in improvements in endothelial function and significant blood pressure reduction. The purpose of the present study was to evaluate the differences between spironolactione and chlorthalidone in hypertensive elderly patients treated with calcium antagonists and angiotensin II receptor blockers. Fourteen uncontrolled hypertensive patients treated with amlodipine and candesartan were included in this study. The study was an open-label randomized crossover comparison of 16 weeks treatment with spironolactone against chlorthalidone added to amlodipine and candesartan. blood pressure significantly decreased in patients treated with both spironolactone and chlorthalidone. Chlortalidone reduced flowmediated dilation significantly compared to the baseline condition and spironolactone. serum highsensitively C-reactive protein and uric acid increased significantly in chlorthalidone-treated patients compared to spironolactonetreated patients. We conclude that spironolactone may be a more useful add-on therapy than chlorthalidone in hypertensive patients inadequately controlled on candesartan and amlodipine, because spironolactone preserves endothelial function and reduces inflammation compared to chlorthalidone.

Regional left ventricular contractile dynamics in hypertrophic cardiomyopathy evaluated by magnetic resonance imaging

SummaryTo assess regional myocardial function in hypertrophic cardiomyopathy (HCM), we examined systolic wall thickening (%WT) and percent change of segmental wall area (%AR) by cine magnetic resonance imaging. We studied 23 normal volunteers without evidence of heart disease (group 1) and 40 patients with HCM (group 2). Short-axis images of the left ventricle were recorded at the base and the apex, and were divided into five segments. There were no significant differences in %WT and %AR among the segments in group 1, while %WT and %AR at the apex were higher than values for corresponding segments at the base. The patients with HCM (group 2) were classified into three groups according to end-diastolic wall thickness: group 2a, less than 12mm; group 2b, 12–15 mm and group 2c, greater than 15 mm. Both the %WT and %AR at the base were significantly higher in group 2a than in the other groups, but were significantly lower in group 2c than in group 1 or group 2a (%WT and %AR in groups 1, 2a, 2b, and 2c, respectively: 51 ± 29 and 19 ± 17; 83 ± 40 and 34 ± 18; 47 ± 38 and 16 ± 14; and 32 ± 21 and 9 ± 8). Both %WT (40 ± 24) and %AR (14 ± 12) at the apex were significantly lower in group 2c than in the other groups (87 ± 45 and 38 ± 31 in group 1; 89 ± 41 and 39 ± 31 in group 2a; and 61 ± 27 and 24 ± 15 in group 2b). Myocardial shortening in the normal volunteers was greater at the apex than at the base. In patients with HCM, regional myocardial function was decreased in association with the degree of hypertrophy, with the wall function of the normal segments appearing to be increased in a possible compensatory mechanism.

Ventricular tachycardia in a patient with cardiac lipoma.

These images demonstrate ventricular tachycardia (VT) associated with cardiac lipoma in the left ventricle. A 22-year-old man suffered from an attack t)f palpitations and faintness, for which he was admitted to our hospital. He was found to have regular tachycardia at a rate of 230/min. The tachycardia was terminated by lidocaine. Echocardiography and cardiac catheterization revealed a large mass in the left ventricle beneath the mitral valve.

Apical hypertrophy associated with rapid T wave inversion on the electrocardiogram

SummaryA 53-year-old man who had no chest pain and no family history of heart disease demonstrated a rapid T wave change on an electrocardiogram, from a positive T wave to a giant negative T wave, within 1 year. Echocardiography showed no left ventricular hypertrophy before or after the T wave change. Cine-magnetic resonance imaging revealed focal apical hypertrophy after the appearance of the giant negative T wave. Although T wave inversions sometimes develop within a short period in patients with hypertrophic cardiomyopathy, they are rare in a patient without hypertension or chest pain.