Pacing-induced palmar sweating evaluated by unique hygrometer: possible implications of sympathetic activation during tachycardia

Although reflex sympathetic activation is a major determinant of the haemodynamic tolerability of ventricular tachycardia (VT), the methods for evaluating this aspect during on-going VT remain invasive and complicated. Palmar sweating as an indirect but non-invasive measure of sympathetic activity was estimated by means of a unique hygrometer under right ventricular (RV) rapid pacing (up to 150 beats min-1) replicating VT, and concurrent monitoring of aortic blood pressure in five patients with various kinds of cardiac arrhythmias in our electrophysiological laboratory. The peak palmar sweating rate in arbitrary units was augmented as the RV pacing rate increased and was proportional to the pacing-induced fall in systolic blood pressure (SBP), with a correlation coefficient of more than 0.903 (P<0.006). The slope of linearity between the sweating rate and the fall in SBP varied among individual patients, with greater sweating amplitude in the younger patients even with the same extent of fall in SBP. This preliminary study suggests sympathetic acceleration caused by haemodynamic deterioration under simulated VT, and therefore this protocol may be able to predict the haemodynamic tolerability of sustained monomorphic VT.

Extracellular matrix regulation in the development of Syrian cardiomyopathic Bio 14.6 and Bio 53.58 hamsters

The myocardium contains a collagen matrix composed primarily of collagen and fibronectin, which are major determinants of the myocardial architecture, structural integrity and mechanical properties. The present study was undertaken to determine the age-related changes of the accumulation and degradation of the collagen matrix in Syrian myopathic hamsters, of the Bio 14.6 and Bio 53.58 strains. Those hamsters were used as models for hypertrophic and dilated cardiomyopathy, respectively. The heart to body weight ratio in the Bio 14.6 strains was higher (P<0.05) than that in the age-matched F1b strains. In the Bio 53.58 strains, the heart to body weight ratio was higher at 8 and 42 weeks of age than that in the F1b strains. The collagen content increased from 22 weeks of age in both Bio hamsters compared with age-matched F1b hamsters (P<0.05). In both cardiomyopathic hamsters, the mRNA expressions for type I and type III collagen and fibronectin all increased with aging; however, the fibronectin expression in the Bio 14.6 strains increased more at 22 weeks of age than at 42 weeks of age. The left ventricular MMP-1, MMP-2 and MMP-9 activities in Bio 53.58 strains increased with aging. However, in the Bio 14.6 strains, although MMP-1 activities increased with aging, MMP-2 and MMP-9 activities decreased at 42 weeks of age in comparison to those at 22 weeks of age. Thus, the MMP activation differed between two cardiomyopathic models at the stage of heart failure, although the collagen synthesis was elevated in both models. In conclusion, it would seem that the relative balance between the synthesis and the removal of collagen may contribute to the changes in the left ventricular geometry in two different types of cardiomyopathy.

Successful treatment of cytomegalovirus colitis with ganciclovir in a patient with adult T cell leukemia lymphoma: case report

An 84-year-old patient with adult T cell leukemia lymphoma (ATLL) developed diarrhea on day 5 of chemotherapy and was diagnosed with cytomegalovirus (CMV) colitis. Sigmoidoscopy revealed multiple superficial erosions surrounded by a flare. Computed tomography (CT) and ultrasonogram of the abdomen revealed marked thickening of the colonic mucosa. There were 186 CMV antigen-positive leukocytes per 31,000 white blood cells (WBC). A colonic biopsy specimen showed typical CMV nuclear inclusions. Immunohistological study of the specimen was positive for CMV antigen. Administration of ganciclovir (DHPG) 500 mg/day for 14 days improved the diarrhea and other symptoms. On day 30 of the chemotherapy, the patient developed diarrhea again but was diagnosed with pseudomembranous colitis instead of CMV colitis. At that time, CMV antigenemia and a histologic study for CMV were negative. The stool was positive for Clostridium difficile toxin antigen. ATLL patients are believed to be immunocompromised hosts and often develop opportunistic infections such as CMV infection. Most suffer from CMV pneumonia at the end of their course of therapy. Few gastrointestinal (GI) CMV infections are seen in ATLL patients and details of CMV colitis have never been reported. When an ATLL patient develops diarrhea that barely responds to conventional therapy, CMV colitis and pseudomembranous colitis should be listed in the differential diagnosis.

[Risk factors for sudden death during hospitalization]

To determine the risk factors for sudden deaths in hospitalized patients, 209 patients (103 men and 106 women, age 76.7 +/- 12.6 years old, mean +/- S.D.) who died in 1996 were divided into two groups and their records were analyzed. One group, the sudden death group (SD), consisted of 16 patients who had stayed in the hospital for 2 weeks or more before the onset of symptoms that led to death within 24 hours. Those who died more than 24 hours after symptoms began were placed into the non-sudden death group (NSD). Fourteen patients who died within 2 weeks of admission were not analyzed in this study. Comparing the data of the two groups led to the following findings. First, the major causes of death in the SD group were exacerbation of chronic cardiac failure (5 cases), acute cardiac failure (2 cases), exacerbation of chronic respiratory failure (2 cases) and acute respiratory failure (2 cases). Second, patients in the SD group were significantly older than those in the NSD group, and had significantly more prescriptions for digitalis. Third, patients in the SD group had higher levels of hemoglobin and hematocrit, lower levels of BUN and a higher cardiothoracic ratio. Fourth, patients in the SD group had a higher incidence of ST abnormalities and T wave abnormalities in their electrocardiograms. Brugada syndrome or long QT syndrome were not seen in either group. Taken together, these findings suggest that aged patients with cardiac failure and myocardial ischemia may be at higher risk of sudden death.

A patient with a hemoglobin variant (Hb JLome) unexpectedly detected by HPLC for glycated hemoglobin (Hb A1c)

A rare hemoglobin variant, Hb JLome, was identified by chance in a male patient with diabetes mellitus (DM). The patient had no evidence of anemia or hemolysis. However, when his glycated hemoglobin (Hb A1c) was examined by high-performance liquid chromatography (HPLC) to assess the state of his DM, an abnormal Hb was unexpectedly detected on the chromatogram. The morphology of the red blood cells was normal. A fast-moving band as well as a normally moving Hb band, of roughly equal intensities, were observed by cellulose acetate membrane electrophoresis. The oxygen equilibrium curve was essentially normal (P50 = 3.59 kPa). In other words, the ability of the patient's Hb to carry oxygen was nearly the same as that of typical Hb A. The stability of his Hb in isopropanol was normal, and all the functions of his Hb that were tested were essentially normal. The identity of the abnormal Hb was finally determined, by sequencing the globin gene, to be Hb JLome, which is produced by a point mutation changing AAG to AAC at the 59th codon in exon 2 of the Hb beta chain. As previously reported, replacing the beta 59 lysine with asparagine does not affect the function of Hb or the red blood cells. There have been only five documented cases of Hb JLome in Japan. Interestingly, all these cases are from Kyushu Island. When an abnormal chromatogram for Hb A1c is unexpectedly obtained, it is worthwhile searching for an abnormal Hb, even if there are no signs that suggest its existence, such as anemia, hemolysis, erythrocytosis, or cyanosis.

Effects of hepatic HDL-related mRNAs on plasma prebeta HDL in cholesterol-fed rabbits

This study was undertaken to determine; 1) the effect of cholesterol enriched diet on prebeta-migrating (prebeta) HDL levels, 2) the effect of the diet on plasma proteins and/or activities likely associated with prebeta HDL (cholesteryl transfer protein (CETP), lecithin-cholesterol acyltransferase (LCAT) and apolipoprotein (apo)A-I), 3) the effect of the diet on the corresponding hepatic mRNAs and 4) the correlation between the hepatic mRNAs and prebeta HDL. Rabbits were fed 0.1% (low) cholesterol (LC group, n = 6) or 0.5% (high) cholesterol diet (HC group, n = 6) for 6 weeks. Plasma CETP activities, plasma total apoA-I and prebeta apoA-I concentrations in the HC group were significantly increased (58.95 +/- 2.37%, 191.52 +/- 13.93 mg/dl, 44.21 +/- 1.14 mg/dl, respectively) compared with the LC group (39.36 +/- 3.62%, 152.85 +/- 8.61 mg/dl, 30.12 +/- 2.79 mg/dl, respectively)(p < 0.05). Plasma LCAT activities did not differ significantly (56.65 +/- 7.19 vs 57.41 +/- 8.21; HC vs LC). Hepatic CETP, LCAT and apoA-I mRNA levels were determined using reverse transcription polymerase chain reaction (RT-PCR). Hepatic CETP mRNA levels, compared to GAPDH mRNA levels as a control, were increased in the HC group (2.226 +/- 0.115) compared with the LC group (1.649 +/- 0.170) (p < 0.05), while hepatic LCAT and apoA-I mRNA levels were unchanged. Thus, plasma concentration of prebeta HDL, CETP activity and the amount of hepatic CETP mRNA were increased in response to the dietary intake of cholesterol. Multiple regression analyses showed that only hepatic CETP mRNA levels had a positive correlation with plasma prebeta HDL concentration (p = 0.04). These results indicate that individual variations in hepatic CETP mRNA levels in rabbits fed a cholesterol diet probably has a major influence on the determination of plasma prebeta HDL concentration.

[Use of hemostatic clips for endoscopic hemostasis and closure of an esophageal laceration caused by a fish bone]

An 82-year-old woman was admitted to our hospital because of hematemesis. She had had a feeling of a foreign substance in her throat for one week after having eaten fish. On admission she had a fever of 38 degrees C, Hb of 5.8 g/dl, CRP level of 8.8 mg/dl, and bilateral pleural effusions. Endoscopy revealed a deep longitudinal laceration with active bleeding in the esophagus that also caused mediastinitis. Endoscopic hemostasis and closure of the laceration was done with hemostatic clips. The esophageal injury seemed to have been caused by a fish bone. After the treatments described here were carried out, the patient's condition rapidly improved.

[An elderly case of post-bulbar Dieulafoy's ulcer]

The case is a 79-year-old man who came to our hospital with melena as chief complaint. Emergency endoscopy showed spurting bleeding from a small ulcer. We diagnosed as Post-Bulbar Dieulafoy's ulcer and performed hemostatic procedure with hemostatic clips. The forth endoscopy (7 days after admission) showed fresh clot and oozing bleeding after the third hemostatic clipping. Although we performed hemostatic procedure with the injection therapy of hypertonic saline epinephrine solution (HSE). The effective hemostatic procedure is discussed with reference to some related literature.

Effect of dietary omega-3 eicosapentaenoic acid supplements on cholesteryl ester transfer from HDL in cholesterol-fed rabbits

We investigated the reactivities of cholesteryl ester transfer protein (CETP) in Japanese white rabbits fed either a low-cholesterol diet containing 0.1% cholesterol (Control group) or a diet containing 0.1% cholesterol plus 17.5% omega-3 eicosapentaenoic acid (omega-3 20:5, EPA) of 4.5% (w/w) total lipid (EPA group) for 6 weeks. The plasma total and LDL cholesterol levels and aortic cholesterol content were all significantly higher in the EPA group than in the control group. The aortic cholesterol content significantly correlated with LDL cholesterol (r = 0.81). HDL cholesterol levels tended to be lower in the EPA group compared with control group, which was not statistically significant. The plasma VLDL cholesterol levels did not differ significantly between the groups. In addition, no significant differences were observed in the plasma CETP activity or lecithin:cholesterol acyltransferase (LCAT) activity between the groups. However, the cholesteryl ester (CE) mass transfer from fractionated HDL in the EPA group to excess VLDL and/or LDL as acceptors by purified CETP increased significantly compared with the control group, even if the acceptors were fractionated from either the EPA or the control group. Fatty acid analyses of CE showed that the omega-3 18:3, 20:4 or omega-3 20:5 fatty acid acyl groups in CE of HDL were significantly more transferred to apo B-containing lipoproteins compared with the 14:0,16:0, 18:0, 18:1 or 18:2 fatty acid acyl groups in CE of HDL during the incubation period. The amount of CE in HDL containing omega-3 18:3 and omega-3 20:5 fatty acid acyl groups was greater, while the amount of CE containing 18:2 fatty acid acyl groups was smaller in the EPA group than in the control group. These results show that although CETP itself did not change, the transfer of CE in HDL to apo B-containing lipoproteins by CETP increased in the rabbits fed a diet containing EPA as the HDL is modified by the diet, which may partly explain why atherogenicity was thus found to progress in the rabbits fed a cholesterol plus EPA diet.

The effects of renin-angiotensin system inhibition on aortic cholesterol content in cholesterol-fed rabbits

To investigate how the renin-angiotensin system (RAS) might be involved in cholesterol-induced atherosclerosis, we studied the effects of a nonsulhydryl angiotensin converting enzyme (ACE) inhibitor, enalapril, and an angiotensin II receptor antagonist, E-4177, in cholesterol fed rabbits. Japanese white rabbits were randomly divided into four groups with the following dietary regimens: group A (n = 8) received a standard diet; group B (n = 8) had a 0.5% cholesterol diet; group C (n = 8) had a 0.5% cholesterol diet plus enalapril (10 mg/kg/day, p.o.); group D (n = 8) received a 0.5% cholesterol diet plus E-4177 (20 mg/kg/day, p.o.) and were fed these diets for 5 weeks. Enalapril or E-4177 had no significant effect on either the total plasma or the high density lipoprotein (HDL) cholesterol concentrations. However, the aortic cholesterol content in groups C and D was equally significantly less than that in group B. The plasma and aortic ACE activities were significantly reduced only in group C compared with those in the other groups. The aortic ACE mRNA and AT1 mRNA levels were assessed by a reverse transcription polymerase chain reaction (RT-PCR). The aortic ACE mRNA level was only significantly less in group C than in any of the other groups. The aortic AT1 mRNA level increased significantly in group B compared with that in group A and was significantly and equally reduced in both groups C and D compared with that in group B. These data indicate that angiotensin II rather than ACE may therefore be related to aortic cholesterol content. It follows therefore that the inhibition of angiotensin II by either ACE inhibitor or angiotensin II (type 1) receptor antagonist may play a role in prevention of atherosclerosis.

[Surgical treatment of secondary chronic colonic pseudo-obstruction]

A 74-year-old woman was admitted to the hospital because of constipation and marked abdominal distension. She had become to be bedridden after cerebral infarction 10 years previously, and was tabescent due to vomiting. A left hemicolectomy and colostomy were performed because conservative therapy seemed to be ineffective. The postoperative course was good and her nutritional status improved.

Chronic low-dose treatment with enalapril induced cardiac regression of left ventricular hypertrophy

Numerous studies suggest that the renin angiotensin system (RAS) is involved in the development of cardiac hypertrophy. In the present study we produced cardiac hypertrophy in rats subjected to abdominal aortic banding and also induced cardiac regression by the administration of an angiotensin converting enzyme (ACE) inhibitor, enalapril, at 3, 10 and 30 mg/kg/day. Each drug was administered to the rats for 6 weeks from 6 weeks after aortic banding. The left ventricular weight significantly decreased at 10 and 30 mg/kg/day of enalapril as well as the systolic blood pressure. Using the reverse transcriptase polymerase chain reaction, the increased levels of ACE and AT1 mRNA were significantly inhibited in the aortic banding rats treated with the above concentrations of enalapril. The ACE activity in both the plasma and heart tissue preparations was significantly inhibited by enalapril. Similar observations were also seen after the administration of angiotensin type 1 receptor blockade, E-4177, into the aortic banding rats. The treatment with enalapril at 3 mg/kg/day did not reduce the left ventricular weight or the systolic blood pressure in the aortic banding rats. However, this low-dose treatment did significantly decrease the left ventricle to body weight ratio in the aortic banding rats without a reduction of the systolic blood pressure. Therefore, using the low-dose enalapril, the ACE activity in plasma was in part inhibited and the levels of ACE mRNA also decreased in the heart tissue of aortic banding rats, while the level of AT1 mRNA showed no such decrease. These results thus indicate that chronic ACE inhibitor at low doses has a beneficial effect on the regression in the pressure-induced cardiac hypertrophy. It is thus assumed that this effect may also contribute to the presence of an alternate pathway for the conversion of angiotensin I to angiotensin II which might also act as a possible mechanism for cardiac regression.

Regression of hypertrophy after myocardial infarction is produced by the chronic blockade of angiotensin type 1 receptor in rats

The efficacy of angiotensin converting enzyme (ACE) inhibitors is well known to prevent the formation of angiotensin II (Ang II) by these agents. The objective of the present study was to evaluate the hemodynamic, biochemical, and morphological responses to Ang II receptor blockade with E-4177, 3-[(2'-carboxybiphenyl-4-yl) methyl]-2-cyclopropyl-7-methyl 3H-imidazol[4,5-b] pyridine, in rats with a healing myocardial infarction that had been induced by the surgical occlusion of the left main coronary artery. The left ventricular weight increased 8 and 12 weeks after infarction in comparison to that in sham-operated rats. Among the rats with experimental infarction, treatment with E-4177 significantly decreased the left ventricular weight. Although the infarct size was not affected by E-4177, its administration ameliorated the elevated end-diastolic pressure and reduced the systolic pressure. The effects of this agent on the levels of Ang II type 1 (AT1) receptor mRNA and ACe mRNA were evaluated in the non-infarcted myocardium by reverse transcriptase polymerase chain reaction and binding assays. Treatment with E-4177 reduced both the elevated AT1 mRNA and the number of Ang II receptors, but not the ACE mRNA or ACE activity. While the receptor affinity remained unchanged with this agent, the collagen concentration was decreased. On the other hand, the depressed Na+/Ca2+ exchange activity was restored in the non-infarcted myocardium at 8 and 12 weeks after injury to the level seen in the sham-operated rats. These findings suggest that the AT1 receptor antagonist, E-4177, has a beneficial effect on the hemodynamics in spite of the lack of any improvement in the infarct size. These observations may be partly attributed to the prevention of angiotensin II formation during the period of post-infarction healing.

Effects of enalapril on the collagen matrix in cardiomyopathic Syrian hamsters (Bio 14.6 and 53.58)

The hereditary cardiomyopathic strain of Syrian hamster has been extensively studied as a model of cardiomyopathy of heart failure. We attempted to determine whether an angiotensin converting enzyme (ACE) inhibitor, enalapril, prevents the increase in extracellular collagen matrix which connects the myocytes in cardiomyopathy. Enalapril was administered at an average dosage of 10 mg/kg per day to 10- to 20-week-old hamsters with hypertrophic (Bio 14.6) and dilated (Bio 53.58) cardiomyopathy, as well as to control Syrian hamsters (F1 beta). Collagen concentration estimated by hydroxyproline concentration and the collagen type III:I ratio significantly increased in the hearts of the Bio 14.6 and Bio 53.58 strains at 20 and 40 weeks of age as, compared with those in age-matched F1 beta hamsters. When Bio 14.6 hamsters were given enalapril for 10 weeks from 10 to 20 weeks of age, the collagen concentration, the collagen type III:I ratio and type III collagen mRNA expression were significantly decreased, compared with those in untreated animals of the same strain. After the administration of enalapril, scanning electron microscopic examination also revealed a decrease in fibrillar collagen accumulation in the interstitium and the network surrounding the cardiac myocytes. These prophylactic effects were not observed in the Bio 53.58 strain. These results indicate that the administration of ACE inhibitor prevents type III collagen production in the Bio 14.6 strain but not in the Bio 53.58 strain of Syrian hamster.

Interleukin 1 alpha-induced expression of manganous superoxide dismutase reduces myocardial reperfusion injury in the rat

We investigated the effects of pretreatment with interleukin (IL)-1 alpha on the expression of manganous (Mn) superoxide dismutase (SOD) mRNA and reperfusion-induced arrhythmias and the size of myocardial infarct in rats. Male Wistar rats received 10 mg intraperitoneal injections of human recombinant IL-1 alpha. Their hearts were thereafter isolated at 6, 12, 24, 36 h. A Northern analysis showed that Mn-SOD mRNA was mainly expressed in the heart and slightly in kidney, but not in any other organs. The expression of Mn-SOD mRNA peaked at 6 h after the injection of IL-1 alpha. The Mn-SOD protein content was most increased 12 h after injection. In the isolated heart model, the rats were pretreated with IL-1 alpha 24 h earlier and their hearts were perfused by the Langendorff method. After 20 min of ischemia which was induced by a ligation of a coronary artery, reperfusion-induced arrhythmias were observed. There were no significant differences in the incidence of ventricular arrhythmias between the IL-1 alpha pretreated and the untreated hearts. IL-1 alpha pretreatment significantly reduced the mean duration of the ventricular arrhythmias and also delayed the onset of arrhythmias. The effect of IL-1 alpha pretreatment was also investigated in a 30-min model of ischemia followed by a 3-min reperfusion in anesthetized rats. The infarct size expressed as a percentage of the area at risk was significantly reduced in the IL-1 alpha pretreated hearts compared with the untreated hearts. The left ventricular systolic pressure increased significantly in rat hearts pretreated with IL-1 alpha. Our results therefore showed that the pretreatment with IL-1 alpha induced the overexpression of Mn-SOD mRNA in the rat hearts and also suggested that pretreatment with IL-1 alpha 24 h before ischemia reduced the risk of ischemia-reperfusion injury.

Modulation of adrenergic receptors during regression of cardiac hypertrophy

OBJECTIVE

To determine whether alpha 1- or beta-adrenergic receptors are altered during regression of cardiac hypertrophy produced by antihypertensive agents.

DESIGN AND METHODS

Cardiac hypertrophy was induced in rats by aortic banding. After 6 weeks banding the rats were treated with an angiotensin converting enzyme (ACE) inhibitor (enalapril), an alpha 1-adrenergic antagonist (bunazosin) or a beta-adrenergic antagonist (propranolol) for 6 weeks to induce regression. The numbers of alpha 1- and beta-adrenergic receptors, haemodynamics, tissue noradrenaline content and tissue ACE activity were measured.

RESULTS

Regression of cardiac hypertrophy occurred after treatment of aortic banded rats with a high dose of enalapril, bunazosin or propranolol, and was accompanied by a reduction in systolic blood pressure. The number of alpha 1- or beta-adrenergic receptors was unchanged by propranolol treatment, but the number of alpha 1-adrenergic receptors was increased in the hearts of rats treated with bunazosin. A low dose of enalapril (3 mg/kg body weight) caused regression of hypertrophy without a concomitant reduction in blood pressure, and decreased the number of alpha 1-adrenergic receptors. The dissociation constants for alpha 1- and beta-adrenergic receptors were not different among the experimental groups, and the positive derivatives of left ventricular pressure was unaltered in rats treated with a low dose of enalapril but was reduced by the other drugs.

CONCLUSION

Of the three drugs tested, only the low dose of enalapril affected adrenergic receptors during regression of cardiac hypertrophy, causing a decrease in alpha 1-adrenergic receptor number without a reduction in blood pressure. This effect may be explained by non-haemodynamic actions of the ACE inhibitor enalapril, probably by modulation of peripheral sympathetic activity.

Computer analysis of Holter electrocardiogram

Computer analysis is indispensable for the interpretation of Holter ECG, because it includes a large quantity of data. Computer analysis of Holter ECG is similar to that of conventional ECG, however, in computer analysis of Holter ECG, there are some difficulties such as many noise, limited analyzing time and voluminous data. The main topics in computer analysis of Holter ECG will be arrhythmias, ST-T changes, heart rate variability, QT interval, late potential and construction of database. Although many papers have been published on the computer analysis of Holter ECG, some of the papers was reviewed briefly in the present paper. We have studied on computer analysis of VPCs, ST-T changes, heart rate variability, QT interval and Cheyne-Stokes respiration during 24-hour ambulatory ECG monitoring. Further, we have studied on ambulatory palmar sweating for the evaluation of mental stress during a day. In future, the development of "the integrated Holter system", which enables the evaluation of ventricular vulnerability and modulating factor such as psychoneural hypersensitivity may be important.

Effect of metoprolol on the beta-adrenoceptor density of lymphocytes in patients with dilated cardiomyopathy

We investigated the effect of the beta 1-selective blocker metoprolol on the beta-adrenergic receptor density of circulating lymphocytes in patients with dilated cardiomyopathy. Nine men in New York Heart Association functional classes II (six patients) and III were given metoprolol for 6 months (mean dose 45.6 +/- 18.1 mg). Their cardiac function was assessed by echocardiography. Although there was no difference in the heart rate or pressure rate products, the end-systolic and end-diastolic dimensions significantly decreased in six patients after metoprolol treatment. The ejection fraction, fractional shortening, and mean left ventricular circumferential shortening were significantly increased after the treatment. beta-Adrenoceptor densities of lymphocytes, examined by iodine 125-labeled iodocyanopindolol, were reduced in patients at entry but recovered to normal levels after the metoprolol treatment. The dissociation constants did not differ at any stage of the disease. The relationship between beta-adrenoceptor densities in lymphocytes and echocardiographic parameters showed a positive correlation with the plasma norepinephrine concentration. This study thus provides evidence that long-term metoprolol therapy for dilated cardiomyopathy is associated with beta-receptor up-regulation, and the restoration of myocardial beta-receptor density may be associated with the improved cardiac function as determined by echocardiography.

Effects of amiloride on the mechanical, electrical and biochemical aspects of ischemia-reperfusion injury

Although many causal factors have been proposed for the ischemia-reperfusion injury, the exact mechanisms for interdependent derangements of mechanical, electrical and metabolic events remains unclear. For this purpose, the Langendorff-perfused rat hearts were subjected to regional brief ischemia followed by reperfusion to study the protective effects of amiloride, an inhibitor of Na(+)-H+ exchange. Amiloride (0.1 mM) attenuated the rise in tissue Na+ and Ca2+, both duration and incidence of arrhythmias (p < 0.05 vs. control), sarcolemmal injury (assessed by Na-K ATPase) and lipid peroxidation (assessed by malonedialdehyde formation) during reperfusion. Treatment of hearts with monensin, a sodium inophore, reversed the protective effects of amiloride. Reduction in transsarcolemmal Na+ and pH gradients during ischemia exhibited protective effects similar to those seen with amiloride. These results suggest that cardiac dysfunction, sarcolemmal injury and triggered arrhythmias during ischemia-reperfusion are due to the occurrence of intracellular Ca2+ overload caused by the activation of Na(+)-H+ exchange and Na(+)-Ca2+ exchange systems in the myocardium.

Effect of angiotensin converting enzyme inhibitor on regression in cardiac hypertrophy

Cardiac hypertrophy in rats was produced by aortic banding for 6 weeks and regression of hypertrophy in these experimental animals was induced by administration of angiotensin converting enzyme inhibitor, enalapril (10 mg/kg/day) for 6 weeks. The left ventricular muscle mass and systolic pressure were decrease upon treating the hypertrophied rats with enalapril. This drug also decreased the number of alpha 1-adrenoceptors in hypertrophied myocardium without any changes in beta-adrenoceptors. The regression of cardiac hypertrophy in spontaneously hypertensive rats by enalapril for 10 weeks was not associated with any alterations in alpha 1-adrenoceptors in hypertrophied myocardium, but was decreased in beta-adrenoceptors. Effects of enalapril on extracellular matrix in the myocardium was also observed in regression of hypertrophy in which the type III collagen mRNA expression and collagen contents were reduced in comparison with those of hypertrophied myocardium. These results indicate that regression of cardiac hypertrophy is not always associated with a decrease in the number of alpha 1-adrenergic receptors and that the beneficial effects of enalapril in the hypertrophied heart in aortic banding animals may be of some specific nature.

Clinical effects of nitrendipine on variant angina pectoris

The clinical effects of nitrendipine, a new calcium antagonist, were investigated in a single-blind test on 21 patients with variant angina pectoris. The efficacy of the drug was evaluated on the basis of frequency of anginal attacks and Holter electrocardiographic findings during different treatment periods at doses of 10 mg once a day (period I) and 20 mg once a day (period II). The number of anginal attacks decreased significantly from a pretreatment level of 2.1 +/- 0.3 per day to 0.7 +/- 0.2 per day in treatment period I and 0.3 +/- 0.1 per day in treatment period II (p less than 0.01, p less than 0.001, respectively). The consumption of sublingual nitroglycerin tablets decreased significantly in both treatment periods in comparison with the observation period before treatment (p less than 0.01, p less than 0.001, respectively). In 20 patients with continuous ECG monitoring, the frequency of ST-segment elevation was 4.5 +/- 1.0 per day during the pretreatment period; it decreased significantly to 0.9 +/- 0.6 per day in treatment period I and 0.5 +/- 0.3 per day in treatment period II (p less than 0.01, p less than 0.001, respectively). The duration and the maximum magnitude of ST-segment elevation also improved significantly in both treatment periods. These results demonstrate the efficacy of nitrendipine in the treatment of variant angina at a single daily dose of 10 mg.

Sarcolemmal Ca2+ transport activities in cardiac hypertrophy caused by pressure overload

To examine Ca2+ transport activities in sarcolemmal membrane in cardiac hypertrophy caused by pressure overload, rats were subjected to aortic banding for 28 days. Heart-to-body weight ratio was increased by 46% in aortic-banded animals in comparison with the sham-operated rats. Ouabain-sensitive Na+-K+-ATPase activity in sarcolemma (SL) from hypertrophied hearts was not different from that in the control preparation. The initial rate of Na+-dependent Ca2+ uptake in SL vesicles from the hypertrophied hearts was stimulated by 53% compared with the control vesicles. ATP-dependent Ca2+ uptake and Ca2+-stimulated adenosinetriphosphatase (ATPase) activities in SL from hypertrophied hearts were increased by 35%. The number of Ca2+ channels estimated by [5-methyl-3H]nitrendipine binding was decreased by 33% in SL from hypertrophied hearts. Total and individual phospholipid contents in the hypertrophied heart preparations were not different from those in the control, except that phosphatidylcholine and phosphatidylethanolamine contents were significantly increased. Sarcolemmal preparations from hypertrophied hearts from the 22-wk-old spontaneously hypertensive rats exhibited changes in Na+-Ca2+ exchange and Ca2+-pump activities (similar to those observed in banded hearts), whereas the Na+-K+-ATPase activity decreased, [3H]nitrendipine binding increased, and phospholipid contents were not different. Thus, although differences were defined between two types of hypertrophy, these results suggest alterations in the sarcolemmal Ca2+ transport activities that may serve as an adaptive mechanism for the removal of Ca2+ from the myocardial cells during the development of cardiac hypertrophy.

Frequency characteristics of the heart rate variability produced by Cheyne-Stokes respiration during 24-hr ambulatory electrocardiographic monitoring

Spectral analysis of heart rates during 24-hr ambulatory electrocardiographic monitoring has been carried out to characterize the heart rate spectral components of Cheyne-Stokes respiration (CSR) by using fast Fourier transformation (FFT). Eight patients with congestive heart failure were selected for the study. FFT analyses have been performed for 614.4 sec. Out of the power spectrum, five parameters were extracted to characterize the CSR. The low peak frequencies in eight subjects were between 0.0179 Hz (56 sec) and 0.0081 Hz (123 sec). The algorithms used to detect CSR are the followings: (i) if the LFPA/ULFA ratios were above the absolute value of 1.0, and (ii) the LFPP/MLFP ratios were above the absolute values of 4.0, then the power spectrum is suggestive of CSR. We conclude that the automatic detection of CSR by heart rate spectral analysis during ambulatory ECG monitoring may afford a tool for the evaluation of the patients with congestive heart failure.

[Analysis of EEG, respiration, and ECG by 24-hour polygraphic study in a case of aortitis syndrome associated with epilepsy]

The relationships between electroencephalographic changes and cardio-respiratory responses were analysed by using 24 hour ambulatory simultaneous monitoring of EEG, respiration, ECG in a patient with aortitis syndrome. Circadian changes of "absence" attacks, effects of anti-convulsive drugs on epileptic attacks, and respiratory arrest and abnormalities of the cardiorespiratory integration were clarified.

Modulation of Na+-Ca2+ exchange in cardiac sarcolemmal vesicles by Ca2+ antagonists

The purpose of this study was to examine the effect of three classes of Ca2+ antagonists, diltiazem, verapamil and nifedipine on Na+-Ca2+ exchange mechanism in the sarcolemmal vesicles isolated from canine heart. Na+-Ca2+ exchange and Ca2+ pump (ATP-dependent Ca2+ uptake) activities were assessed using the Millipore filtration technique. Sarcolemmal vesicles used in this study are estimated to consist of several subpopulations wherein 23% are inside-out and 55% are right side-out sealed vesicles in orientation. The affect of each Ca2+ antagonist on the Na+ dependent Ca2+ uptake was studied in the total population of sarcolemmal vesicles, in which none of the agents depressed the initial rate of Ca2+ uptake until concentrations of 10 microM were incubated in the incubation medium. However, when sarcolemmal vesicles were preloaded with Ca2+ via ATP-dependent Ca2+ uptake, cellular Ca2+ influx was depressed only by verapamil (28%) at 1 microM in the efflux medium with 8 mM Na+. Furthermore, inhibition of Ca2+ efflux by verapamil was more pronounced in the presence of 16 mM Na+ in the efflux medium. The order of inhibition was verapamil greater than diltiazem greater than nifedipine. These results indicate that same forms of Ca2+-antagonist drugs may affect the Na+-Ca2+ exchange mechanism in the cardiac sarcolemmal vesicles and therefore we suggest this site of action may contribute to their effects on the myocardium.

Effect of a new calcium antagonist, nilvadipine, on variant angina pectoris evaluated by 24-hour Holter electrocardiography

The clinical effect of nilvadipine, a new calcium antagonist, was investigated in a single blind trial in 19 patients with variant angina pectoris. The efficacy of the drug was evaluated on the basis of frequency of anginal attacks and Holter electrocardiographic findings during observation periods and during two treatment periods when the drug was given in doses of 4 mg twice a day or 4 mg 3 times a day. The frequency of anginal attacks and the consumption of sublingual nitroglycerin tablets decreased significantly in both treatment periods in comparison with those in the observation period before treatment, but in the observation period after treatment tended to increase in comparison with those during the second treatment period. The frequency and duration of ST-segment elevation and the maximum ST-segment elevation confirmed by Holter electrocardiography also improved significantly in both treatment periods, compared with those in the observation period before treatment. Our findings show that nilvadipine is effective for variant angina pectoris at doses of 4 mg twice a day.

Role of the suprachiasmatic nuclei of the hypothalamus on diurnal rhythm in cardiac arrhythmias

Ambulatory EGG and EEG recordings were recorded under a 14/10-h light-dark illumination schedule using rats. The rats consisted of two groups: a suprachiasmatic (Sch) lesioned group (n = 5) and a normal control group (n = 5). Bilateral Sch nuclei were lesioned electrically (DC, 2.5 mA, 30 s for each) using a pair of platinum electrodes 0.3 mm in diameter. After recovery from surgery, recordings of ECGs (leads I, II, and III) and EEGs from the cortex and the left dorsal hippocampus were continued for 6 days. Diurnal periodicity in bradyarrhythmia (sinoatrial block, atrioventricular block) and heart rate was analyzed by the least square fit of 24-h cosines. Significant diurnal rhythm was observed in control rats, whereas Sch-lesioned rats showed no significant diurnal rhythm. The integrity of the Sch nuclei, therefore, is necessary for the generation and/or the expression of diurnal periodicity in bradyarrhythmia in rats.

[Pituitary hormone responses to exercise at high altitudes]

The secretory responses of the anterior pituitary hormone to physiological stress were studied in healthy male volunteers. Measurements of blood LH, FSH, Prolactin, GH, ACTH, lactate, pyruvate and hematocrit were made from blood samples taken at rest, after 15 minutes at sea level, and at an altitude of 4000 m and 5500 m modulated in a climate-controlled room. The results are summarized as follows: Blood levels of Prolactin and ACTH were increased after exercise at a high altitude. Blood levels of LH and FSH after exercise at each altitude were not significantly different from those at rest. Blood GH level was increased after exercise at any altitude. Blood levels of lactate and pyruvate were increased after exercise at any altitude. These results suggest that the secretory response of the anterior pituitary hormone to physiological stress is prominent in Prolactin, GH and ACTH but not in FSH and LH.

Influence of glucocorticoids on brain serotonin metabolism in rats

It has been suggested brain serotonin (5HT) plays a role in regulation of the hypothalamic-pituitary-adrenal system, although none of the experimental approaches so far reported has produced unequivocal results, mainly on account of the static tissue 5HT level or the known effects of drugs being employed in interpretation of their data. The present study in rats of the possible feedback influence of glucocorticoids on the brain 5HT was designed to analyze the dynamic turnover of its metabolism. Intracisternal injection of corticosterone (COR) caused no significant changes in 5HT content but increased its turnover dose-dependently in the cortex-cerebellum and the rostral brain stem including the hypothalamus, and lowered the serum COR level at doses less than 5.0 micrograms/kg, reducing its effect with increasing doses. Intracisternal or intraperitoneal administration of miliary doses of dexamethasone (DEX) decreased 5HT turnover in the same brain portions. The effects of glucocorticoids on the brain 5HT metabolism were more potent when injected intracisternally, especially onto the rostral brain stem. Although COR and DEX played controversial roles, the present results suggest that adrenal glucocorticoids may directly act on brain 5HT metabolism and there may be a feed-back relation between adrenal glucocorticoid and brain 5HT.

Well-controlled comparative study of the clinical effectiveness of intravenous mexiletine and procainamide on ventricular premature contraction

In a well-controlled study the clinical efficacy of a single intravenous injection of mexiletine (3 mg/Kg) on ventricular premature contractions was compared with that of procainamide (10 mg/Kg) using continuous electrocardiographic recordings. Of the 56 subjects studied, 55 were analyzed. These consisted of 28 cases in the mexiletine group and 27 in the procainamide group. The backgrounds of both groups were considered to be equivalent. Effectiveness on VPC ("marked and moderate improvement", as judged by the subcommittee) was seen in 88% of the mexiletine group and 84.6% of the procainamide group. This difference was not significant. The duration of efficacy was almost the same in the 2 groups. Overall improvement was the same as improvement in VPC. No significant difference was observed in the incidence of side effects. Five patients in the mexiletine group and 3 in the procainamide group reported side effects. The main side effect was light-headedness in the mexiletine group and a decrease in blood pressure in the procainamide group. A decrease in blood pressure was observed in 1 case in the mexiletine group but this was restored by an intravenous infusion of noradrenaline. Mexiletine had little effect on blood pressure, while procainamide induced a drop in the systolic pressure. This difference was significant. Overall utility ("markedly and moderately useful", as judged by the subcommittee) was seen in 84.0% of the mexiletine group and 84.6% of the procainamide group. There was no significant difference between the 2 groups. From the above results, it is concluded that mexiletine (3 mg/Kg) is as efficacious as procainamide (10 mg/Kg) in the treatment of VPC but that, unlike procainamide, mexiletine has little effect on blood pressure.

Studies of arrhythmias by 24-hour polygraphic recordings: relationship between atrioventricular block and sleep states

The relationship between AV conduction disturbances and sleep states was investigated using continuous polygraphic recordings for one full night. The results were as follows: (1) In the case of first-degree AV block, the phasic shortening of the PQ interval was observed during rapid eye movement (REM) sleep. (2) In the case of second-degree AV block (Wenckebach type), the conduction ratio increased transiently during REM sleep and significant relationships were observed between the number of nonconducted P waves and the mean heart rate in each sleep stage. (3) In the case of advanced AV block, complete AV block was observed less frequently during REM sleep and the period of falling asleep. Since the reproducibility of these results from night to night has not yet been investigated, additional evaluation is required.

The usefulness of Holter monitoring in the evaluation of antiarrhythmic drug efficacy for tachycardia

Using Holter monitoring tachycardia was found in 145 out of 2058 patients suffering from various underlying diseases. Three thousand seven hundred and forty monitorings were performed. The mean age of patients was 54.5 years with a range of 19 to 83 years. The observed tachycardia was classified into three types: tachycardia with short duration, tachycardia with long duration and tachycardia with complex form. The attacks of tachycardia were more frequently observed during periods of physical activity than during sleeping periods. The relationship of the number of tachycardia with short duration between 24-hour Holter monitorings was examined in order to establish day to day variability of the attacks. The 95% confidence interval about the resultant regression line was calculated and the percent reduction required for the evaluation of drug efficacy to avoid the chances of interference of spontaneous variation was found to be about 44.0, 55.0 and 82% when the total number of attacks during a 24-hour period were 50, 100 and 1,000, respectively. Holter monitoring showed higher positive results as compared to exercise testing for detection of tachycardia. Higher correlation coefficients between numbers of premature ventricular contractions (PVCs) and the plasma concentrations of procainamide or N-acetylprocainamide were observed in 3 or more successive PVCs than in individually occurring PVCs. Using repeated 24-hour Holter monitorings a significant reduction in the number of tachycardia was observed when the therapeutic concentration was reached after the combined or single administration of the drug. These results suggest that repeated Holter monitorings, exercise testing and determination of plasma level of the drug may be useful for the evaluation of antiarrhythmic drug efficacy for tachycardia.

Sleep and night-type arrhythmias

The relationship between arrhythmias and sleep states was investigated in patients with night-type arrhythmias, which were detected by 24-hour electrocardiogram recordings using the Holter Avionics system. These patients were examined using all-night polygraphic recordings and sleep states were divided in to 5 groups according to the standard sleep stage scoring manual as stage I, II, III, IV, and REM sleep. Patients were divided into 5 groups: (1) grade 2 ventricular premature contractions (VPCs), (2) grade 4a VPCs, (3) grade 4b VPCs, (4) supraventricular premature contractions, and (5) paroxysmal tachyarrhythmias such as paroxysmal atrial fibrillation or paroxysmal supraventricular tachycardia. The paroxysmal tachyarrhythmia group showed a significant increase in arrhythmia incidence during REM sleep (p less than 0.05). However, the subjects with other arrhythmias showed no significant increase during REM sleep, but grade 2 VPCs showed a tendency to increase in sleep stage IV (0.05 less than p less than 0.1). These results suggest that there are 2 types of arrhythmias influenced by sleep. The first type is affected by a phasic increase in sympathetic nervous tone during REM sleep and the second type is related to an increase in vagal tone during the night.