Comparative analysis of the therapeutic effects of long-acting and short-acting loop diuretics in the treatment of chronic heart failure using (123)I-metaiodobenzylguanidine scintigraphy.

AIMS: Loop diuretics are essential for the treatment of chronic heart failure (CHF) but short-acting diuretics are reported to induce sympathetic nervous system (SNS) activation. This study was performed to compare therapeutic effects of two loop diuretics, long-acting azosemide and short-acting furosemide, using (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy. METHODS AND RESULTS: Twenty-two patients with New York Heart Association class II-III heart failure and left ventricular dysfunction, who required treatment with a loop diuretic, were included. In this crossover study, 11 patients were randomized to azosemide treatment first and the remaining 11 patients to furosemide. Treatments were administered for 6 months and then patients were crossed over to the second treatment. (123)I-MIBG scintigraphy was performed before and 6 months after the start of treatment with each loop diuretic. Early and delayed images were obtained 20 min and 4 h after administration of (123)I-MIBG, respectively; and the heart/mediastinum (H/M) ratio and washout rate (WR) were measured. In addition, left ventricular ejection fraction (LVEF), levels of brain natriuretic peptide (BNP), and norepinephrine were measured before and 6 months after the start of treatment. No differences were observed between the two groups in terms of concomitant medication, cause of heart failure, H/M ratio, WR, BNP, norepinephrine, or LVEF. The azosemide group exhibited a significant increase in delayed image H/M ratio, and a significant decrease in WR and norepinephrine after the final administration compared with the furosemide group. CONCLUSION: This study indicates that azosemide suppresses SNS activation compared with furosemide in patients with CHF, suggesting that long-acting loop diuretics may have more beneficial effects on the prognosis of CHF.

Anatomical characteristics of myocardial bridge in patients with myocardial infarction by multi-detector computed tomography.

BACKGROUND: Recent development of multi-detector computed tomography (MDCT) has made the detection of myocardial bridge (MB) easier on the left anterior descending coronary artery (LAD). The LAD segment proximal to the MB is well known to be susceptible to atherosclerosis. Anatomical characteristics of MB on LAD in patients with myocardial infarction (MI) were examined by MDCT. METHODS AND RESULTS: Subjects were 43 MI patients who had MB in the LAD and comprised 2 groups: 14 with culprit lesions in the LAD proximal to MB (culprit group) and 29 without culprit lesions in the LAD (non-culprit group). MB length, MB thickness, and the distance from the orifice of left main trunk (LMT) to MB entrance were compared. Age and coronary risk factors showed no significant difference between the 2 groups. MB length (P=0.011), MB thickness (P=0.035), and index of the length multiplied by thickness of MB (P=0.031) were significantly greater in the culprit group. The distance from the orifice of the LMT to MB entrance was significantly shorter in the culprit group (P=0.006). CONCLUSIONS: Anatomical properties of MB, such as length and thickness of MB as well as MB location, are associated with the formation of culprit lesions of LAD proximal to MB in MI.

Correlation between left ventricular diastolic function and ejection fraction in dilated cardiomyopathy using magnetic resonance imaging with late gadolinium enhancement.

BACKGROUND: The distribution of left ventricular (LV) fibrosis and the percent fibrosis in patients with dilated cardiomyopathy (DCM) were evaluated using late gadolinium enhanced (LGE) MRI. Then the relation with the LV ejection fraction (EF) and deceleration time (DT), an index of diastolic function obtained using echocardiography, was investigated. METHODS AND RESULTS: LGEMRI at 20 min after intravenous injection of Gd-DTPA (0.15 +/-0.03 mmol/kg) was performed in 17 patients with DCM. The distribution of the LV enhanced area and LGE rate (%) were calculated. EF, as well as E/A ratio and DT were obtained using echocardiography. LGE was observed in 15 out of 17 patients (88%) and the enhanced region appeared to represent myocardial fibrosis. The LV fibrosis was often found in the intraventricular septum (IVS), but there were no differences in its distribution. The LGE rate (%) had a correlation between cardiac magnetic resonance ejection fraction (CMREF) (Y = 51.7 - 2.1X [R(2) = 0.23, P<0.001]) and DT (Y = 162.2 +12.0X [R(2) = 0.35, P<0.001]). CONCLUSIONS: The LV fibrosis is often found in the IVS with DCM. A correlation exists between LGE rate (%) to EF on CMR and DT on echocardiography in patients with DCM.

Evaluation of sympathetic activity by 123I-metaiodobenzylguanidine myocardial scintigraphy in dilated cardiomyopathy patients with sleep breathing disorder.

BACKGROUND: Because increased sympathetic nervous activity (SNA) in patients with dilated cardiomyopathy (DCM) associated with sleep breathing disorder (SBD) is known to deteriorate the prognosis of cardiac failure, (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was used as the investigative tool in the present study. METHODS AND RESULTS: The study group comprised 53 patients (47 men, 6 women; mean age 56+/-3 years) with chronic stable DCM. Patients were divided into SBD(+) or SBD(-) group according to 24-h pulse oximetry results. SBD(+) was defined when the 3% oxygen desaturation index was more than 15/h during sleep. In total, 32 patients were SBD(-) and 21 were SBD(+). In both groups, pulse oximetry were performed during sleep and awakening pulse rate, and measurement of the blood levels of catecholamines and B-type natriuretic peptide was performed. MIBG myocardial scintigraphy and echocardiography were performed at the same time. No significant difference was found between the 2 groups in catecholamine levels or left ventricular ejection fraction. However, MIBG had a significantly increased washout rate and a significantly decreased delayed heart to mediastinum ratio in the SBD(+) group compared with the SBD(-) group. CONCLUSIONS: SNA is increased in DCM patients when associated with SBD. MIBG myocardial scintigraphy may be a sensitive method of detecting increased SNA.

Scintigraphic studies on the etiology of Ampulla Cardiomyopathy.

BACKGROUND: Although there are many reports on Ampulla Cardiomyopathy, its etiologic mechanisms are not well known. AIM: Etiology of Ampulla Cardiomyopathy was investigated by myocardial scintigraphy with various nuclear tracers. SUBJECTS AND METHODS: In nine patients with Ampulla Cardiomyopathy, myocardial scintigraphy was performed at acute, subacute and chronic phases. Total defect score (TDS) of tallium-201 (Tl) or technetrium-99m sestamibi (MIBI) myocardial perfusion and iodine-123-beta-methyl-p-iodophenyl penta-decanoic acid (BMIPP) scintigraphies was calculated. Cardio-mediastinal ratio (H/M) and washout rate (WR) of early and delayed images of iodine-123-meta-iodobenzylguanidine (MIBG) scintigraphy were also calculated. The patients in whom TDS of myocardial perfusion scintigraphy at acute phase was 0, were classified into group N (n = 5) and those with TDS > or = 1 into group D (n = 4). RESULTS: TDS of BMIPP at acute, subacute and chronic phases was higher in D than in N; 28.8 +/- 10.3 vs. 7.2 4.7 (p = 0.0039), 15.5 +/- 2.1 vs. 1.0 +/- 0.8 (p < 0.0001) and 2.7 +/- 1.2 vs. 0 (p = 0.05), respectively. WR of MIBG at acute phase was also higher in D (50.3 +/- 5.7% vs. 36.6 +/- 10.5%, p = 0.05). H/M (dH/M) on the delayed images and WR at chronic phase were not different between the two groups. H/M (eH/M) on the early images was lower in D. Blood noradrenaLine (ng/ml) at acute phase was higher in D than in N (1.21 +/- 0.55 vs. 0.45 +/- 0.33, p < 0.05). Left ventricular ejection fraction (LVEF) was decreased in both at acute phase but it was lower in D than in N (48.1 +/- 3.7% vs. 69.9 +/- 9.7%, p < 0.05) at subacute phase. CONCLUSION: These findings suggest that the etiology of Ampulla Cardiomyopathy is neurologically stunned myocardium induced by coronary microcirculatory disorder. Due to the significant amount of time that was necessary for normalization of wall motion in the D group, myocardial scintigraphy is believed to be also useful in assessment of severity.

[Recurrent ampulla cardiomyopathy showing prolonged sympathetic nerve function disorder: a case report].

A 58-year-old woman with chronic renal failure had been undergoing maintenance hemodialysis. Ampulla cardiomyopathy recurred in association with prolonged sympathetic nerve function disorder. Periodical evaluation of the patient's condition using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was continued since the first attack at age 55 years. The initial washout rate was high at 58.3%, and was still high at 33.0% when she was discharged following improvement in wall motion, and remained high at 45.4% 1 year after discharge. Recurrence occurred at age 58 years, when a high washout rate of 48.6% was observed. High washout rate values of 49.5% and 40.1% were also observed 2 and 9 months after discharge, respectively, following improvement in wall motion abnormalities. 123I-MIBG can be used to assess the course of recurrent ampulla cardiomyopathy, and can objectively evaluate sympathetic nerve function disorders. This interesting case suggests that sympathetic nerve function disorder is closely related to the pathophysiology of this disorder.

[Left ventricular dysfunction without brain natriuretic peptide elevation: two case reports].

Brain natriuretic peptide (BNP) is an useful marker for the differential diagnosis of dyspnea and pleural effusion of unknown origin. BNP elevation indicates myocardial overload. Two patients were admitted to our hospital with abnormal electrocardiogram or dyspnea. Left ventricular ejection fractions were below 40% and BNP levels were below 2.0 pg/ml in both patients. The diagnoses were dilated cardiomyopathy (DCM) based on coronary angiography, and pathological examination and suspected secretion insufficiency of BNP. Immunohistochemistry for BNP showed no significant difference in BNP expression in the myocardium between patients with DCM and elevated BNP and the present patients. We recommend that patients with intractable dyspnea undergo echocardiography at least once even if their BNP level is low.

Carvedilol prevents myocardial fibrosis in hamsters.

The objective of the present study was to determine if carvedilol protects against myocardial degeneration and fibrotic change, and reduces mortality in TO2 hamsters. Carvedilol was administered intraperitoneally to 8 week-old TO2 hamsters for 21 weeks at a dose of 11 mg/kg/day. There were 15 TO2 hamsters in the carvedilol group (group C) and 10 in the untreated group (group N). The control group consisted of 11 Fb hamsters (group F). The mortality rate was determined from the number of surviving hamsters after 29 weeks. Myocardial fibrosis was evaluated by MRI and histopathological examination. EF and LVDd were determined by echocardiography at 8 and 29 weeks, while the MRI score was calculated at 29 weeks. Mortality, histopathological fibrosis, and MRI score were all lower in group C than in group N. Carvedilol had a protective effect against myocardial fibrosis and decreased the mortality rate in TO2 hamsters.

Primary idiopathic chylopericardium: report of two cases.

Primary chylopericardium is an extremely rare disease. This report presents two cases of this disease, in a 47-year-old man and 21 -year-old woman. Both cases were given diagnosis of primary chylopericardium by chylous pericardial fluid examination and lymphangio-scintigraphy which demonstrated abnormal communication between the left thoracic duct and the pericardial cavity.

Efficacy of contrast-enhanced MR imaging in cardiomyopathy: an experimental study using Bio14.6 hamsters.

RATIONALE AND OBJECTIVES: Myocardial fibrosis was evaluated with magnetic resonance (MR) imaging in Bio14.6 hamsters. MATERIALS AND METHODS: Gated gradient-echo T1-weighted images and spin-echo images with gadopentetate dimeglumine enhancement (0.2 mmol/kg) were obtained. RESULTS: Myocardial enhancement persisted for 13 minutes after administration of gadopentetate dimeglumine, and myocardial signal intensity peaked at 13 minutes on gradient-echo T1-weighted images. The enhanced areas were greater in Bio14.6 hamsters at 25-42 weeks than at 10 weeks. Pathologic data revealed enhancement with inflammation at 10 weeks and fibrosis with vessel proliferation at 25-42 weeks. Pathologic fibrotic change was greater at 32-42 weeks than at 10 weeks. The myocardium of 42-week-old Bio14.6 hamsters showed remarkable contrast enhancement, which continued for 13 minutes. There was no correlation between gadolinium enhancement and pathologic findings in the evaluation of myocardial degeneration and fibrosis. CONCLUSION: Gadolinium-enhanced MR imaging was useful for estimating myocardial fibrotic changes with vessel proliferation and myocardial damage.