Relationship between insulin resistance and accumulation of coronary risk factors.

We examined correlations between the frequency of insulin resistance and the accumulation of coronary risk factors in residents of rural comities in Japanese, using simple criteria for determination of insulin resistance based on evaluation by the euglycaemic-hyperinsulinaemic glucose clamp (GC) method. The subjects were 376 men and 589 women living in two rural communities in Japan. We measured body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), triglyceride (TG), HDL cholesterol (HDL), and homeostasis model assessment (HOMA-R). Correlations between HOMA-R and those parameters were examined. To assess the existence of insulin resistance in these subjects, we used a practical index based on the GC method. The subjects with value of HOMA-R >or= 1.73 have insulin resistance. In addition, the HOMA-R was divided into five quantiles based on the frequency distribution (0.60 or below, from 0.61 to 0.82, from 0.83 to 1.18, from 1.19 to 1.69, and 1.70 or higher), to examine the concentration of risk factors in each group. In total, 74 (19.6%) of the men and 119 (20.3%) of the women had insulin resistance (HOMA-R >or= 1.73). It was found that the higher the HOMA-R, the higher was the number of coronary risk factors, such as hypertension, obesity, hypertriglyceridaemia and hypo HDL cholesterolaemia. The number of coronary risk factors was particular high in subjects with HOMA-R >or= 1.70. HOMA-R in the case of no glucose loading is a useful and practical index for evaluation of insulin resistance and coronary risk factors in the epidemiological study.

Cardiac imaging in a patient with anomalous origin of the left coronary artery from the pulmonary artery--a case report.

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is an uncommon congenital heart disease and has a high mortality rate in infancy. However, myocardial ischemia does not develop until adolescence or adulthood in about 10% of patients. Moreover, the diagnosis of ALCAPA is often difficult in cases without heart murmur or cardiac symptoms. The authors report the case of a 31-year-old man with ALCAPA. He was admitted to the hospital for evaluation of mild shortness of breath at exercise, but he had no typical chest symptoms due to myocardial ischemia or heart failure until age 31 and he had no heart murmur. Moreover, electrocardiogram did not show an old myocardial infarction or myocardial ischemia. Therefore, the authors did not suspect ALCAPA until they performed transthoracic echocardiography and exercise-stress single photon emission computed tomography (SPECT) with Tc-99m-tetrofosmin. The final diagnosis was established from the results of coronary arteriography. In the present case, a transthoracic echocardiogram showed abnormal coronary circulation, and exercise-stress SPECT revealed reversible myocardial ischemia. Transthoracic echocardiography and myocardial SPECT imaging could be a useful noninvasive tools for diagnosing the ALCAPA.

[A report of successful surgical management of right coronary artery to right atrium fistula forming giant aneurysms at the posterior wall of the right atrium].

A 52-year-old woman was diagnosed by echocardiography to have a fistula of the right coronary artery (RCA) and the right atrium (RA). Aortography demonstrated a remarkably dilated and undulating fistulous tract originating from the region corresponding to the orifice of the normal RCA. The fistulous tract detoured to the posterior wall of the RA, and forming 2 aneurysms there, opened to the RA. A RCA of normal size originating midway of the fistulous tract was also observed. The patient was operated on under cardio-pulmonary bypass. Aortocoronary saphenous vein graft to the RCA having normal diameter was performed, and the RCA was ligated in the proximal side of the anastomosis. The orifice of the fistulous tract from the aorta was closed with a patch and the entrances into the RA were also closed by pledgetted mattress sutures. The post operative course was uneventful and the patient is now doing well without any complaints.

[A case of beriberi heart--with special reference to the rapid effect of fursultiamine on hemodynamics].

A 33-year-old man was admitted to Kushiro City General Hospital on February 27, 1989, because of palpitation, shortness of breath and anasarca. Eight months previously he had noted the onset of pretibial edema, which had progressed to anasarca. He had had a meal only once a day for nine months. Physical examination revealed a blood pressure of 114/46 mmHg and pulse rate of 80/min. The 3rd sound was audible. No rales in the chest and no hepatosplenomegaly were noted. Ascites, pretibial edema and anasarca were present. Vibration sensation was diminished, and the deep tendon reflexes were absent in the legs. The blood thiamine level on the 4th day of hospitalization decreased to 2.9 micrograms/dl. The red cell transketolase activity and TPP effect on the 10th hospital day were 0.76 IU/gHb and 11%, respectively. A chest roentogenogram showed pulmonary congestion and cardiomegaly (CTR 61.3%). The electrocardiogram showed non-specific T wave changes. On the echocardiogram, remarkable pericardial effusion and diffuse hypertrophy of the left ventricular wall were observed. In addition, the left ventricular wall motion showed a hyperkinetic state. On the basis of these findings, the diagnosis of beriberi heart was made. The hemodynamic study performed on the 10th hospital day showed a remarkable high cardiac output (CO) of 10.7 l/min and an extremely reduced total peripheral resistance (TPR) of 352 dynes.sec.cm-5. 15 min after intravenous administration of Fursultiamine 100 mg, CO decreased to 7.24 l/min and TPR increased to 848 dynes.sec.cm-5. Following the administration of Fursultiamine 75 mg, po/day, his symptoms and abnormal findings of clinical examination data rapidly improved.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of hypertrophic cardiomyopathy with right ventricular outflow obstruction manifested during three-year follow-up study].

A case is reported of a 55-year-old female with idiopathic hypertrophic cardiomyopathy, which was accompanied with outflow obstruction in the right ventricle developed during the previous 3 years without lesion of the left ventricle. In 1984, she was admitted to our hospital to be examined for cardiac murmurs and abnormal electrocardiogram including ST depression and inverted T. The findings of echocardiography and cardiac catheterization revealed non-obstructive hypertrophic cardiomyopathy. She had been treated with sympathetic beta-blockade and calcium antagonist for 3 years until she complained of dyspnea on exertion, and she was readmitted to our hospital in 1987. Echocardiographic findings showed protrusion of the ventricular septum toward the right ventricle and systolic turbulent flow along the right ventricular outflow tract (by pulsed Doppler technique). A pressure gradient of 20 mmHg across the protrusion was detected by the examination of the cardiac catheter. However, neither protrusion nor pressure gradient was observed in the left ventricular outflow tract as well as that in 1984. Idiopathic hypertrophic cardiomyopathy has been described as involving both ventricles, and outflow obstruction is the usual hemodynamic finding in the left ventricle. However, right ventricular outflow obstruction is the usual hemodynamic finding in the left ventricle. However, right ventricular outflow obstruction with the left ventricular outflow tract intact has been very rare. In addition, in this case, the change of hemodynamic characteristics from non-obstructive to obstructive hypertrophic cardiomyopathy, and the development of these changes only in the right ventricle were observed during the last 3 years.

A case of normotensive primary aldosteronism--comparison with 13 previously experienced cases with hypertension.

A 47-year-old woman with normotensive primary aldosteronism is reported. In this case, hypopotassemia was found, but the patient's blood pressure was within the normal range. Her condition was diagnosed as primary aldosteronism without hypertension, which is very rare, based on an increased level of plasma aldosterone concentration, low plasma renin activity, and a typical finding of aldosterone-producing adenoma by adrenal scintigraphy. In the present case, similar values for urinary volume, renal function, plasma aldosterone concentration, plasma renin activity, plasma volume, total exchangeable sodium, urinary kallikrein excretion and a similar weight of the resected adenoma, but a shorter duration between the onset of symptom and hospital admission were observed as compared with those in 13 previously experienced cases of primary aldosteronism with hypertension. Thus, a shorter duration of primary aldosteronism appears to be an important factor in explaining the mechanism of normotension. However, we were unable to reach a definite conclusion and this is only a hypothesis. Further investigation will be required to clarify the mechanism of normotension in primary aldosteronism.

The role of L-carnitine in the pathogenesis of cardiomegaly in patients with chronic hemodialysis.

Many reports have suggested that cardiac dysfunction with cardiomegaly is more often observed in patients with chronic hemodialysis. Moreover, cardiac dysfunction has been thought as one of the most important factors affecting the prognosis of these patients. In this study, in order to clarify the role of l-carnitine in the pathogenesis of cardiomegaly, 33 patients with chronic hemodialysis were studied using the multivariate analysis method. Among the factors which may affect cardiac function, the following 10 variables were examined. 1) age, 2) duration of dialysis, 3) plasma carnitine, 4) serum total cholesterol, 5) serum HDL-cholesterol, 6) triglyceride, 7) systolic blood pressure, 8) diastolic blood pressure, 9) left ventricular voltage on a electrocardiogram at rest and 10) hematocrit. The plasma carnitine levels in these patients were markedly reduced and inversely correlated with the cardiothoracic ratio (CTR) on the chest X-ray films (r = 0.38, p less than 0.05). In principal component analysis, the CTR was closely related to hematocrit and plasma carnitine levels. By multiregression analysis, both hypo-carnitinemia and anemia were independently shown to be important causes of cardiomegaly. Thus, it is suggested that the cardiomegaly in patients with chronic hemodialysis may be improved by supplemental therapy with l-carnitine, even in cases with severe anemia.