Biomedical subjects

M Akahoshi

Publications and source records attributed to M Akahoshi.

At least 19 recordsLinked to original sources

PubMed2006

Association between ADAM33 polymorphisms and adult asthma in the Japanese population.

BACKGROUND: ADAM33, a member of the ADAM (a disintegrin and metalloprotease) family, is a putative asthma susceptibility gene recently identified by positional cloning. It is important to know whether the association exists in ethnically diverse populations. OBJECTIVE: To assess whether genetic functional variants of ADAM33 relate to the susceptibility or some phenotypes in adult patients with bronchial asthma in a Japanese population. METHODS: We searched for single nucleotide polymorphisms (SNPs) in ADAM33 by PCR-directed sequencing and identified 48 SNPs. Fourteen SNPs were selected with regard to the LD pattern, and genotyped by Taq-Man and PCR-RFLP methods. We conducted an association study of ADAM33 with 504 adult asthmatic patients and 651 controls, and haplotype analyses of related variants were performed. RESULTS: Significant associations with asthma were found for the SNPs T1 (Met764Thr), T2 (Pro774Ser), S2 and V-3 (with the lowest P-value for T1, P = 0.0015; OR 0.63). We analysed the haplotype using these four polymorphisms, and found a positive association with haplotype CCTG (P = 0.0024). CONCLUSION: Our results replicate associations reported recently in other ethnic populations, and suggest that the ADAM33 gene is involved in the development of asthma through genetic polymorphisms.

ADAM Proteins↗

PubMed2004

Anti-monocyte chemoattractant protein-1 gene therapy attenuates nephritis in MRL/lpr mice.

OBJECTIVE: Monocyte chemoattractant protein-1 (MCP-1) is up-regulated and recruits and activates inflammatory cells in human diffuse proliferative lupus nephritis (DPLN) and in nephritis of lupus model MRL/lpr mice. The aim of this study was to examine whether anti-MCP-1 gene therapy inhibits the progression of nephritis in MRL/lpr mice. METHOD: An NH(2)-terminal deletion mutant of the MCP-1 gene, 7ND, was injected into skeletal muscles of MRL/lpr mice with advanced stage nephritis to blockade MCP-1 and its receptor (CCR2) signalling pathway. RESULT: Histological findings of kidneys in treated mice, which received more than four injections of 7ND, showed that protection against renal injury resulted from reduced infiltration of leucocytes. Therefore, this therapy has been shown to prolong the life span of MRL/lpr mice. CONCLUSION: Anti-MCP-1 gene therapy is specifically effective in the localized inflammatory region. The data presented here indicate that this anti-MCP-1 gene therapy may be effective adjunct in the management of DPLN.

Animals↗

PubMed2004

Cataract in atomic bomb survivors.

PURPOSE: Ophthalmologic examinations were conducted on atomic bomb (A-bomb) survivors 55 years after exposure. MATERIALS AND METHODS: A-bomb survivors who had been exposed before 13 years of age at the time of the bombings in 1945 or who had been examined in a previous study between 1978 and 1980. The examinations, conducted between June 2000 and September 2002, included slit-lamp examination, digital photography and a cataract grading system for three parts of the lens (nucleus, cortex and posterior subcapsule) as an outcome variable. Proportional odds logistic regression analysis was conducted using the lowest grading class as a reference and included explanatory variables such as age, sex, city, dose and various cataract-related risk factors. When the grades in an individual differed, the worst grade was used. RESULTS: Results indicate that odds ratios (ORs) at 1 Sv were 1.07 (95% confidence intervals [CI] 0.90, 1.27) in nuclear colour, 1.12 (95% CI 0.94, 1.30) in nuclear cataract, 1.29 (95% CI 1.12, 1.49) in cortical cataract and 1.41 (95% CI 1.21, 1.64) in posterior subcapsular cataract. The same was true after excluding 13 people whose posterior subcapsular cataracts had been previously detected. CONCLUSION: Significant radiation effects were observed in two types of cataracts in A-bomb survivors.

Adolescent↗

PubMed2004

Polymorphisms in ADAM33 are associated with allergic rhinitis due to Japanese cedar pollen.

BACKGROUND: A recent report provided evidence that a disintegrin and metalloprotease domain 33 (ADAM33), a member of the ADAM family, is a novel susceptibility gene in asthma linked to bronchial hyper-responsiveness. However, there has been no investigation of the genetic role of ADAM33 variants in nasal allergy. OBJECTIVE: The purpose of this study was to test the association between ADAM33 polymorphisms and Japanese cedar pollinosis (JCPsis), a most common seasonal allergic rhinitis in Japan. METHODS: We conducted a case-control association study among a Japanese population, involving 95 adult individuals with JCPsis and 95 normal healthy controls. A total of 22 single-nucleotide polymorphisms (SNPs) in ADAM33 were genotyped using PCR-based molecular methods. RESULTS: Six SNPs of ADAM33 gene, three in introns (7575G/A, 9073G/A and 12540C/T) and three in the coding region (10918G/C, 12433T/C and 12462C/T), were strongly associated with JCPsis (P = 0.0002-0.022 for absolute allele frequencies) and most of the SNPs were in linkage disequilibrium with each other. A higher frequency of the common alleles of these SNPs was noted for the subjects with JCPsis in comparison with healthy controls. We also identified a haplotype associated with the disease susceptibility. In addition, associations were found between ADAM33 polymorphisms and various cedar pollinosis phenotypes including clinical severity, eosinophil counts in nasal secretion and allergen-specific IgE levels in sera, but not total serum IgE levels. CONCLUSION: These results indicate that polymorphisms in the ADAM33 gene are associated with susceptibility to allergic rhinitis due to Japanese cedar pollen, but the functional relationship still needs clarification.

ADAM Proteins↗

PubMed2004

Absence of association between the MCP-1 gene polymorphism and histological phenotype of lupus nephritis.

Lupus nephritis presents two polar histological patterns, diffuse proliferative glomerulonephritis (DPGN) and membranous glomerulonephritis (MGN). In the kidney tissue of DPGN, numerous mononuclear cells were seen in the interstitium and glomeruli; on the other hand in MGN, infiltrating cells were less frequent. Monocyte chemoattractant protein-1 (MCP-1) is a potent chemoattractant for monocytes, T-cells, and natural killer cells. In this study we assessed the significance of the MCP-1 gene in determination of the histological phenotype in lupus nephritis. There was no association between the risk of DPGN and the MCP-1 gene genotype.

Adolescent↗

PubMed2003

Strong polarization toward Th1 immune response in ANCA-associated glomerulonephritis.

AIM: Human immune response can be classified into 2 different subsets of T helper cells (Th1 and Th2) based on the pattern of cytokine production. In modern immunology, Th1/Th2 paradigm helps to explain the different inflammatory effector pathways and outcomes in human diseases. The present study was designed to determine the type of immunological response that influences anti-neutrophil cytoplasmic antibody-(ANCA) associated glomerulonephritis (GN) using cytokine analysis of peripheral T cells and diseased kidney tissues. PATIENTS AND METHODS: We analyzed peripheral blood Th1/Th2 ratio in 91 patients with primary GN, including 10 cases of ANCA-associated GN. Tissues were immunostained with markers of T cells and macrophages and osteopontin (OPN). Intrarenal expression of IFN-gamma and IL-4 mRNAs was evaluated by reverse transcriptase (RT)-PCR. RESULTS: Peripheral Th1/Th2 ratio was significantly higher in ANCA-associated GN (19.4 +/- 9.4, mean +/- SD, n = 10), than those in healthy controls (7.6 +/- 4.1, n = 27), IgA nephropathy (9.6 +/- 5.6, n = 45), membranous nephropathy (7.1 +/- 4.4, n = 13), minimal-change nephrotic syndrome (8.2 +/- 4.5, n = 13) and focal segmental glomerulosclerosis (8.3 +/- 3.9, n = 10) (p < 0.01, each). In 7 of 10 cases of ANCA-associated GN, Th1/Th2 ratio decreased significantly after treatment with corticosteroid from 21.0 +/- 12.0 to 9.0 +/- 6.6 (p < 0.05). Immunohistochemical staining showed numerous infiltrating T cells, macrophages and OPN-positive cells in both glomerular tuft and cellular crescent; OPN-positive cell distribution was similar to that of macrophages. Intrarenal expression of IFN-gamma mRNA was strongly enhanced whereas a weak expression of IL-4 mRNA was observed especially in advanced cases showing tubulointerstitial injury. CONCLUSION: Both peripheral and renal immune responses are strongly polarized toward Th1 type immune response in ANCA-associated GN. Peripheral Th1/Th2 ratio may reflect the immune responses in renal injury of ANCA-associated GN.

Adult↗

PubMed2002

Association between IL-4 genotype and IL-4 production in the Japanese population.

We have identified that there are only two IL-4 gene haplotypes (I and II) in the Japanese population. There are significant differences among three genotypes (I/I, I/II and II/II) in the IL-4 producing proportion of peripheral Th cells using intracellular cytokine detection assay. These results make it likely that IL-4 genotype could influence the type of immune response.

Cells, Cultured↗

PubMed2002

The effects of body mass index on age at menopause.

OBJECTIVE: We examined which of body mass index (BMI, kg/m(2)), serum cholesterol (mg/dl), or systolic blood pressure (SBP, mm Hg) affected age at natural menopause. DESIGN: A population-based follow-up program. METHODS: We determined the age at natural menopause in 1136 women followed biennially since their first examination in 1958-1959 through the 16th examination in 1988-1989. Four-hundred and ninety-three naturally menopausal women were classified into three groups by BMI, serum cholesterol and SBP measurement levels at age 40 or 41 y: the upper 25%, middle 50%, and lower 25%. We then studied whether there was a difference in age at menopause among the three groups thus classified. The 1136 natural menopausal women were also classified as early (n=454; 45-49 y at menopause (48.3+/-1.2 y)) or late (n=682; >or=50 y at menopause (52.3+/-1.6 y)) menopausal and compared for premenopausal trends in BMI, serum cholesterol and SBP in the early and late menopausal women by means of a longitudinal data analysis model. RESULTS: When women were classified into the three groups based on a BMI that was measured at 40 or 41 y, age at menopause in the upper 25% (50.4+/-2.8 y) was significantly higher (P<0.05) than that in the lower 25% (49.7+/-2.8 y). The entire premenopausal trend in BMI in late menopausal women shifted upward compared to that in early menopausal women. On the other hand, the premenopausal trend more than 4 y before menopause in serum cholesterol and the entire premenopausal trend in SBP in late menopausal women were identical to those in early menopausal women. CONCLUSION: Among the variables studied, only BMI is related to age at menopause, and the greater the BMI, the later the age at menopause.

Adult↗

PubMed2002

Ventricular activation and recovery measured in electrocardiographic limb leads correlate with measurements from specific areas in body surface mapping.

AIMS: Dispersion of ventricular depolarization-repolarization in 12-lead electrocardiograms (ECGs) has been reported to provide noninvasive information on arrhythmogenicity. However, there are two methods to calculate the dispersion from ECGs including and excluding limb leads. The aim of this study was to examine whether temporal parameters from limb leads represent activation and repolarization of a particular part of the body surface. METHODS AND RESULTS: We compared the temporal parameters of activation time (AT), activation-recovery interval (ARI), and recovery time (RT) from limb leads of ECGs with those from an 87-lead body surface maps. The study population consisted of 50 normal subjects (25 men and 25 women, 19.4 +/- 1.6 years). The temporal parameters in leads I, II, and III were highly (r > 0.9) correlated with those in unipolar leads over the left lateral, left lower, and right lower chest, respectively. The temporal parameters in leads aVR, aVL, and aVF showed a significant correlation (r > 0.8) with those in unipolar leads over the right upper, left upper, and lower anterior chest, respectively. The mean AT, ARI, and RT from each limb lead of ECG were almost the same as those of unipolar leads over the corresponding areas of the body surface. CONCLUSIONS: These findings suggest that ATs, ARIs, and RTs from limb leads may represent those from unipolar leads of particular areas over the body surface in normal subjects. The temporal parameters from limb leads of ECGs may provide information on activation and repolarization as well as the precordial leads of ECGs.

Adolescent↗

PubMed2002

Genetically determined interferon-gamma production influences the histological phenotype of lupus nephritis.

OBJECTIVE: To clarify whether the interferon-gamma (IFN-gamma) gene (IFNG) is associated with the histological phenotype of lupus nephritis. METHOD: We analysed microsatellite polymorphisms located within the first intron of the IFNG gene to determine the genotypes of patients with lupus nephritis WHO class IV (n=24), patients with WHO class V (n=12) and healthy controls (n=61). We used flow cytometric detection of intracellular cytokines to identify CD4(+) T cells producing IFN-gamma. Production of IFN-gamma by peripheral blood mononuclear cells after stimulation with phytohaemagglutinin was evaluated with an enzyme-linked immunosorbent assay. RESULT: The frequency of the IFNG allele 114 was significantly greater in WHO class V patients than in WHO class IV patients. Furthermore, the IFNG 114 +/+ genotype was more frequent in WHO class V than in WHO class IV patients. The level of IFN-gamma and the percentage of IFN-gamma-producing CD4(+) T cells were lower in individuals with genotype 114 +/+ than in individuals with genotype 114 -/-. CONCLUSION: The IFN-gamma gene is associated with the histological phenotype in lupus nephritis.

Adult↗

PubMed2001

Contribution of central amiloride-sensitive transport systems to the development of hypertension in spontaneously hypertensive rats.

This study was conducted to examine if central amiloride-sensitive transport systems are involved in the development and/or maintenance of hypertension in spontaneously hypertensive rats (SHR). Either amiloride (75 microg/60 microl/day) or artificial cerebrospinal fluid (aCSF, 60 microl/day) was infused centrally (i.c.v.) for 4 weeks to development (4-5-weeks-old) and maintenance (10-12-weeks-old) phases of hypertension in SHR. In development phase, amiloride i.c.v. (n=14) blunted the elevation of blood pressure (BP) compared to aCSF i.c.v. (n=9) (amiloride vs. aCSF; after 3 weeks of i.c.v., 146+/-3 vs. 166+/-5 mmHg, P<0.001). The difference of BP at 3 weeks of i.c.v. was canceled after ganglionic block with hexamethonium (115+/-4 vs. 117+/-5 mmHg). Further, pressor responsiveness to norepinephrine was augmented in amiloride i.c.v. rats (amiloride, n=11 vs. aCSF, n=6; %Delta BP at 800 ng/kg/min.: 16.9+/-1.3 vs. 10.8+/-1.4 mmHg, P<0.05) and this augmentation disappeared after ganglionic block. Pressor responsiveness to angiotensin II and cumulative sodium balance did not differ in the two groups. Intravenous administration of amiloride at the same dose did not attenuate the development of hypertension. On the other hand, in maintenance phase, amiloride i.c.v. by the same protocol as in development phase had no effect on BP in SHR. Also, amiloride i.c.v. did not affect BP in normotensive Wistar-Kyoto rats. These results suggest that central amiloride-sensitive transport systems are involved in the development, but not in the maintenance, of hypertension in SHR through the modulation of autonomic neural mechanisms.

Amiloride↗

PubMed2001

Predominance of Th1 immune response in diffuse proliferative lupus nephritis.

OBJECTIVE: Lupus nephritis, which shows various histologic patterns, is a serious complication of systemic lupus erythematosus (SLE). We previously demonstrated the importance of Thl cell-mediated immune response in patients with diffuse proliferative lupus nephritis (DPLN). The aim of this study was to examine the relationship between the peripheral blood Th1/Th2 balance and the intrarenal immune response. METHODS: The Th1:Th2 ratio in peripheral blood was measured by intracellular staining for cytokines with flow cytometry. Immunohistochemical analysis of renal biopsy specimens was performed to clarify the characterization of local infiltrating cells in 3 groups of subjects: SLE patients with World Health Organization (WHO) class IV nephritis (DPLN) (group I; n = 13), SLE patients with WHO class V nephritis (group II; n = 9), and patients with minor glomerular lesions (group III; n = 7). In addition, the histologic activity index and chronicity index were evaluated and correlated with the Th1:Th2 ratio. RESULTS: Immunohistochemical studies showed higher numbers of CD68+ macrophages, CD3 + T cells, and interferon-gamma-positive cells in group I than in groups II or III. Renal tissues from patients in group I also showed up-regulation of expression of osteopontin and CD40, with a small number of infiltrating T cells expressing interleukin-4. Overall, the Thl:Th2 ratio in group I patients (SLE with DPLN) was high and correlated significantly with the histologic activity index, but not with the chronicity index. CONCLUSION: We have identified a predominance of Thl-type response in both peripheral and renal tissues of patients with DPLN, suggesting that the peripheral blood Thl:Th2 ratio directly reflects the local histopathologic findings. In patients with lupus nephritis, the peripheral blood Th1:Th2 ratio could be useful as a parameter that reflects the renal histologic activity or the strength of the local Thl response.

Adult↗

PubMed2001

Effects of age at menopause on serum cholesterol, body mass index, and blood pressure.

Pre- and postmenopausal cholesterol (mg/dl), body mass index (BMI; kg/m(2)), and systolic blood pressure (SBP; mmHg) levels were compared in three age-at-time-of-menopause (ATM) groups to examine the relationship between the three risk factors and age ATM. Cholesterol, BMI, and SBP levels recorded 4 years prior to and 8 years after menopause were examined and increases in these risk factors between the two measurements were noted. The three age groups were: group A (n=49; age ATM [44+/-1]<45), group B (n=395; 45< or =age ATM [48+/-1]<50), and group C (n=578; age ATM [52+/-2]> or =50). Cholesterol levels in premenopausal groups A (169+/-31 mg/dl, 40 years) and B (174+/-31, 44 years) were lower than those in group C (179+/-30, 48 years) (0.05< or =P<0.1 and P<0.05). Because, the increases in cholesterol were greater in group A (41+/-28 mg/dl) than in groups B (32+/-28) and C (29+/-28) (0.05< or =P<0.1 and P<0.05), cholesterol levels were identical among groups despite age differences upon reaching the postmenopause phase: group A (210+/-34, 51 years), group B (206+/-35, 56 years) and group C (208+/-35, 60 years). BMI and SBP increases were not different in groups A, B, and C. Differences in BMI and SBP levels among groups in order of premenopausal age were still observed after menopause. These data suggest that the greater increase in cholesterol associated with early menopause may be related to a higher prevalence of ischemic heart disease (IHD) in younger menopausal women.

Aging↗

PubMed2001

The prevalence, incidence and prognostic value of the Brugada-type electrocardiogram: a population-based study of four decades.

OBJECTIVES: We sought to demonstrate the prevalence, incidence and prognostic value of the Brugada-type electrocardiogram (ECG) in a general population. BACKGROUND: The Brugada syndrome is characterized by evidence of right bundle branch block and ST segment elevation in the right precordial leads, as well as sudden death caused by ventricular fibrillation. However, the natural history of the Brugada-type ECG remains unclear. METHODS: We investigated 4,788 subjects (1,956 men and 2,832 women) who were <50 years old in 1958 and had undergone biennial health examinations, including electrocardiography, through 1999. The Brugada-type ECG was defined as a terminal r' wave in lead V(1) and ST segment elevation > or =0.1 mV in leads V(1) and V(2). Unexpected death was defined as sudden death or unexplained accidental death. RESULTS: There were a total of 32 Brugada-type ECG cases; the prevalence and incidence were 146.2 in 100,000 persons and 14.2 persons per 100,000 person-years, respectively. The incidence was nine times higher among men than women, and the average age at presentation was 45 +/- 10.5 years. The Brugada-type ECG appeared intermittently in most cases and was found in 26% of subjects who died unexpectedly. Cox survival analysis revealed that mortality from unexpected death was significantly higher in subjects with a Brugada-type ECG than in control subjects (p < 0.01). Unexpected deaths were more frequent among subjects with the Brugada-type ECG who had a history of syncope (p < 0.05). CONCLUSIONS: The Brugada-type ECG is not a very rare condition in the adult Japanese population. Subjects with a Brugada-type ECG have an increased risk of unexpected death.

Adult↗

PubMed2001

Prolongation of activation-recovery interval over a preexcited region before and after catheter ablation in patients with Wolff-Parkinson-White syndrome.

INTRODUCTION: Preexisting changes in repolarization properties play an important role in T wave abnormalities (cardiac memory) after ablation in patients with Wolff-Parkinson-White (WPW) syndrome. However, no report has provided direct evidence for prolongation of action potential duration (APD) over a preexcited region before and after ablation. METHODS AND RESULTS: We studied 10 patients with ventricular preexcitation due to a left-sided accessory pathway (AP) (group M) and 12 patients with concealed left-sided AP (group C) to clarify prolongation of APD using activation-recovery intervals (ARIs) from epicardial and endocardial unipolar electrograms in patients with WPW syndrome. ARI was calculated from unipolar electrograms at the His bundle and the coronary sinus adjacent to the AP during atrial pacing (100 beats/min) before and 30 minutes after ablation. Before ablation, ARIs at the AP site were significantly longer in group M than in group C (255+/-21 msec vs 211+/-24 msec; P < 0.01), whereas ARIs at the His bundle did not differ between the two groups (255+/-20 msec vs 245+/-27 msec; P = NS). After ablation, group M showed no significant changes in ARIs at the AP and His bundle (256+/-19 msec and 253+/-15 msec) compared with before ablation. CONCLUSION: We found by direct analysis of ARIs from the epicardium that APD prolongation over the preexcited region was present before catheter ablation and persisted after catheter ablation. The gradual changes in repolarization properties, including APD prolongation after discontinuation of AP, may be one mechanism of cardiac memory after catheter ablation in patients with WPW syndrome.

Action Potentials↗

PubMed2001

Activation-recovery intervals of 12-lead electrocardiograms before and after catheter ablation in patients with Wolff-Parkinson-White syndrome.

Preexcitation in Wolff-Parkinson-White syndrome (WPW) has been reported to induce long-lasting changes in ventricular recovery properties. However, there has not been a report concerning changes in the activation-recovery interval (ARI) in 12-lead ECGs before and after catheter ablation (CA) in patients with WPW syndrome. The present study compared changes in ARIs from 12-lead ECGs with those from body surface unipolar leads before and after CA to examine whether ARIs from limb leads of 12-lead ECGs provide useful information on changes in recovery properties in addition to the ARIs from precordial leads. The study population consisted of 27 manifest WPW patients with a left- (n=18, group A) or right-sided accessory pathway (n=9, group B). ARIs in leads I, II, and III were strongly correlated with those in unipolar leads over the left lateral, left lower, and right lower chest, respectively. ARIs in leads aVR, aVL, and aVF showed a significant correlation with those in unipolar leads over the right upper, left upper, and lower anterior chest, respectively. These correlations were maintained before and after CA. Furthermore, in group A, ARIs in lead V1 tended to increase on day 7 post CA compared with before CA and on day 1. In group B, ARIs in lead III significantly decreased on day 7 compared with before CA and on day 1. These findings suggest that ARIs from the limb leads of 12-lead ECGs may represent those from unipolar leads of a particular area over the body surface, and that ARIs from 12-lead ECGs may provide useful quantitative information on changes in recovery properties before and after CA in patients with manifest WPW syndrome.

Adolescent↗

PubMed2001

Correlation between fatty liver and coronary risk factors: a population study of elderly men and women in Nagasaki, Japan.

The relation between fatty liver, detected by ultrasonography as a marker of visceral fat accumulation, and coronary risk factors was studied in 810 elderly men and 1,273 elderly women in Nagasaki, Japan from 1990 to 1992. The prevalence of fatty liver was 3.3% in the male and 3.8% in the female non-obese participants (BMI, body mass index < 26.0 kg/m2) and 21.6% in the male and 18.8% in the female obese participants (26.0 kg/m2 < or = BMI). Fatty liver was significantly (p < 0.01) related to hypercholesterolemia and hypertriglyceridemia in the men and to hypertension, hypercholesterolemia, low-HDL cholesterol, hypertriglyceridemia and diabetes mellitus or impaired glucose tolerance (DM+IGT) in the women independent of age, obesity, smoking and drinking. Non-obesity with fatty liver, rather than obesity with or without fatty liver, had the highest odds ratio for hypertension and low-HDL cholesterol in the men and for hypercholesterolemia, low-HDL cholesterol, hypertriglyceridemia and DM+IGT in the women. The prevalence of fatty liver is the same in elderly men and women, and fatty liver is an independent correlate of coronary risk factors in the elderly.

Aged↗

PubMed2000

Antiarrhythmic efficacy of dipyridamole in treatment of reperfusion arrhythmias : evidence for cAMP-mediated triggered activity as a mechanism responsible for reperfusion arrhythmias.

BACKGROUND: Intracellular calcium overload is believed to play an important role in development of reperfusion arrhythmias. Dipyridamole, an inhibitor of cellular uptake of adenosine, may prevent or terminate reperfusion arrhythmias by reducing intracellular calcium overload. METHODS AND RESULTS: First, we tested for a preventive effect of dipyridamole. Sixty-one patients who underwent primary PTCA for treatment of acute anterior wall myocardial infarction were enrolled in this prospective study. Patients were divided into dipyridamole (DP) and nondipyridamole (non-DP) groups. The 2 groups had similar baseline characteristics. In the DP group, dipyridamole 0.5 mg/kg was infused intravenously for 3 minutes immediately before reperfusion during primary PTCA. Arrhythmias after reperfusion were analyzed from continuous ECG recordings. None of the patients in the DP group (n=23) had accelerated idioventricular rhythms (AIVR) or ventricular tachycardia (VT). In contrast, 7 (18.4%) had AIVR and 3 (7.9%) had VT in the non-DP group (n=38; P<0.01). Second, we tested for a termination effect of dipyridamole. Dipyridamole 0.5 mg/kg was infused intravenously while continuous ECG recordings were obtained in 9 patients who had either sustained AIVR (n=7) or sustained VT (n=2) after reperfusion of occluded coronary artery. Arrhythmias were terminated in all patients. CONCLUSIONS: These results indicate that administration of dipyridamole can prevent and terminate reperfusion arrhythmias such as AIVR and VT. cAMP-mediated triggered activity may, at least in part, be responsible for reperfusion-induced AIVR and VT.

Adenosine↗