Hypertension is not solely a phenomenon of elevation of systemic blood pressure. It frequently occurs in association with a great deal of metabolic derangement's and should never be regarded as coincidental only. Furthermore, a knowledge of these metabolic derangements may provide a clue to unveil the underlying mechanisms how essential hypertension and its associated complications arise. Therefore we devoted our attention to platelet dysfunction and dyslipidemia which are closely associated with atherosclerosis-the commonest complication of hypertension. We found there exists enhanced platelet aggregation in essential hypertension and a variety of its associated atherosclerotic diseases. Such an aberration in platelet function may be modified after administration of antihypertensive medications such as angiotensin converting enzyme (ACE) inhibitors, calcium channel blockades, β blockades and dietary manipulation. We also demonstrated the close association between hypertension and its associated atherosclerotic complications and abnormal lipids profile. Hyper-triglyceridemia which was initially regarded unimportant in the pathogenesis of atherosclerosis is found to be closely related to hypertension. In an intensive review, we found that people in Taiwan has experienced a huge increase in dietary calories and total fat consumption. In order to solve this emerging problem, a national guideline for diagnosis and management of lipid disorders in Taiwan was developed and announced. Through these efforts, we hope we can reduce the cardiovascular morbidity and mortality in Taiwan and even extend our experience to other countries. (Jpn Circ J 1996; 60: 075 - 084)

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The single-field conductance (SF) method for continuous measurement of left ventricular (LV) volume has achieved widespread use. However, it has been shown theoretically that the ratio between the measured conductance and the actual volume varies between the different interelectrode segments of the catheter due to the convex shape of the equipotential planes at the apex and base. The dual-field conductance (DF) method has recently been introduced and reportedly provides a flatter equipotential plane within the LV. In 11 patients, we compared LV volume measured by biplane cineangiography with conductance volume by the SF and DF methods. Strong correlations were found for both the SF method (r=0.98) and the DF method (r=0.99). However, in comparison with the SF method, the DF method gave a regression line with a slope factor, α, that was closer to unity, and the intercept of the regression line was small (p<0.01). The DF method gave a significantly greater segmental stroke volume (SV) in the apex and base than the SF method. The ratio. of the DF segmental SV to the SF segmental SV in the apex increased in proportion to the end-diastolic volume (p<0.05). In conclusion, the DF method may facilitate the accurate measurement of LV volume in the human heart. (Jpn Circ J 1996; 60: 85 - 95)

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The reversibility of right ventricular function in patients with mitral stenosis associated with secondary tricuspid regurgitation (TR) is as yet undetermined. We assessed the right ventricular systolic performance by cardiac catheterization before and 19 months after surgery in 18 patients who underwent DeVega's tricuspid annuloplasty plus mitral valve replacement (MS plus TR group) and in 9 with mitral valve replacement for isolated mitral stenosis (MS group). After surgery, the right ventricular systolic pressure decreased significantly in both groups (both p<0.01). In the MS plus TR group, the postoperative right ventricular end-diastolic and end-systolic volume indices (RVEDVI and RVESVI, respectively) were significantly decreased compared with the respective preoperative values (both p<0.001). No significant difference was noted between the groups with regard to the right ventricular peak-systolic pressure/end-systolic volume index ratio (RVPSP/ESVI) either before or after surgery. Various left ventricular indices were comparable between the groups both before and after surgery. Linear regression analysis revealed significant correlations between RVEDVI and the RVPSP/ESVI, and between RVPSP and the RVPSP/ESVI both before and after surgery. These results indicate that right ventricular systolic performance in patients with MS plus secondary TR became comparable to those that in patients with isolated MS after surgery, and that this was probably due to nearly equivalent right ventricular contractility before surgery. (Jpn Circ J 1996; 60: 96 - 101)

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The effects of stretch and immediate recoil after balloon angioplasty were evaluated in 21 patients with coarctation of the aorta who underwent balloon coarctation angioplasty. A total of 28 procedures were performed in these patients, who ranged in age from 1 month to 17 years with a mean of 4.3 years. The systolic pressure gradient and coarcted diameter changed significantly from 42 ±22 to 14±9 mmHg (P<0.0001) and from 4.0±1.7 to 6.1±2.0 mm (P<0.001), respectively. Immediate recoil was responsible for the loss of 33% of the potentially achievable coarcted dimension. Recoil was determined mainly by the degree of arterial stretch. Gain increased exponentially with an increase in stretch. There was a narrow range of % stretch (60-80%) within which an effective diameter gain could be obtained. Both gain and stretch were the best predictors for late restenosis: patients with a larger immediate gain and stretch developed more restenosis. These results suggest that the stretch-recoil-gain relationship may be clinically important for evaluating the best predictor of late restenosis after balloon coarctation angioplasty. (Jpn Circ J 1996; 60: 102 - 107)

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Background: The healing process, which affects ventricular remodeling, is an important factor in the prognosis of myocardial infarction. We hypothesized that laminin and type IV collagen contribute to extracellular matrix assembly in healing after myocardial infarction. We examined sequential changes in these two components after experimental myocardial infarction in rats. Materials and Methods: Hearts were excised from 1 day to 10 weeks after permanent left coronary ligation in rats. Immunohistochemical staining with a polyclonal antibody to laminin and type IV collagen was performed by the avidin-biotin-peroxidase method. Results: Laminin: On day 3, laminin initially appeared in a wavy fashion in the granulation tissue of the infarct peripheral zone and was not restricted to the cell membrane; the staining distribution in the peripheral zone then gradually increased, reaching a maximum on days 7-11. The distribution progressed from the peripheral zone to the outer lesion of the central zone of the infarct for 1-2 days, and reached the center point after 2 weeks. The extent of the staining distribution gradually decreased after reaching this maximum, but the staining did not completely disappear. Type IV Collagen: Changes in type IV collagen were essentially the same as those in laminin. A wavy staining pattern of type IV collagen appeared in the infarct peripheral zone from day 3, reached its maximum extent on days 7-11, and decreased gradually thereafter. The distribution progressed from the peripheral zone to the outer lesion of the central zone for 1-2 days, reaching the center point after 2 weeks. Conclusion: Laminin and type IV collagen contribute to extracellular matrix formation in the infarct zone relatively early after myocardial infarction. (Jpn Circ J 1996; 60: 108-114)

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Pulmonary venous flow velocity (PVFVe), pulmonary venous dimension (PVD) and transmitral flow (TMF) velocity were examined under various loading conditions in 15 anesthetized closed-chest dogs by transesophageal Doppler echocardiography (TEE). We also compared PVFVe with pulmonary venous flow volume (PVFVo) simultaneously in open-chest dogs using an ultrasonic flow probe. PVFVo decreased by more than 50% and PVD also decreased significantly during preload reduction, while there was no change in PVFVe. This discrepancy between PVFVo and PVFVe was apparently due to the collapse of pulmonary veins. TMF consisted of both rapid-filling flow velocity and atrial flow velocity components (R and A), while PVF consisted of systolic and diastolic forward flow velocity components (S and D). The peak values of R, A, S and D and the time-velocity integrals of each wave (RI, AI, SI and DI, respectively) were measured. There was a significant correlation between the changes in RI and SI/DI during preload reduction (r=0.82, p<0.001) and during after-load increase (r=-0.59, p<0.05). These results suggest that changes in RI with different loading conditions might be attributable to changes in atrial reservoir volume and conduit volume. (Jpn Circ J 1996; 60: 115 - 123)

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Vasospastic angina was demonstrated clinically and angiographically in a 54-year-old patient with systemic triglyceride storage disease and cardiomyopathy. He and his younger sister had been diagnosed in 1985 as having systemic triglyceride storage with Jordans' anomaly. In 1993, he began complaining of rest and effort chest pain in the morning, which was accompanied by ST depression by ECG. Sublingual nitroglycerine was effective for treating this pain. Intracoronary injection of acetylcholine induced severe coronary vasoconstriction in the left anterior descending artery. Left ventricular contraction was diffusely impaired. Deposits of numerous triglyceride droplets and a decrease in the density of myofibrils in cardiocytes were found in the specimens obtained by endo-myocardial biopsy. The impaired left ventricular contraction may have been due to the changes in myocardial cells. His sister complained of a similar chest pain that was completely controlled by calcium channel antagonist. Thus, our cases demonstrated vasospastic angina associated with cardiomyopathy secondary to systemic triglyceride storage disease with Jordans' anomaly, though the causal relationship between these conditions remains unclear. (Jpn Circ J 1996; 60: 124 - 129)

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We experienced a case of a recurrent left atrial myxoma in a pregnant woman with twin fetuses. Normal healthy twins weighing 1430 and 1190 gm were delivered by cesarean section performed under epidural anesthesia at 32 weeks gestation. Neither cardiac failure nor embolisms were observed during pregnancy or delivery. The left atrial myxoma was removed surgically one week after delivery. The infants and mother remain in good health. According to previous reports and our present observations, the decision for cardiac surgery during pregnancy should be based on the maternal and fetal status. (Jpn Circ J 1996; 60: 130 - 132)

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Idiopathic ventricular tachycardia is widely believed to carry a favorable prognosis, although there have also been reports of sudden cardiac deaths. We present a case of sudden death in a patient with apparent idiopathic right ventricular tachycardia. This patient had long-standing and exercise-related symptoms, an essentially negative non-invasive cardiac evaluation, and spontaneous and inducible ventricular tachycardia of left bundle branch block and inferior axis morphology, that was treated with propranolol. After an uneventful 5-year course, the patient died suddenly. Postmortem examination revealed a severely dilated right ventricle and significant replacement of the right ventricular wall with adipose tissue. Interstitial fibrosis was also seen, but only to a very slight degree. (Jpn Circ J 1996; 60: 133 - 136)

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