In order to estimate the pulmonary blood volume between the pulmonary artery trunk and the left atrium (PBV_PAT-LA), simultaneously with the pulmonary extravascular water volume (PEWV) in the chronically stable cardiac patients, we employed the double indicator dilution method using heat as a diffusible indicator and indocyanine green as a non-diffusible indicator. The PEWV was obtained as the extravascular lung thermal volume estimated in the aortic root (LTV_Ao). In the group of hemodynamically normal patients, in spite of ischemic heart disease (G-N, n=22), the mean pulmonary artery wedge (PAW) pressure was 9.3±3.9 mmHg (mean ± SD), PBV_PAT-LA was 89.5±1.71 ml/kg, LTV_Ao was 5.71±1.37 ml/kg and PBV_PAT-LA /LTV_Ao ratio was 1.64±0.44. In the group of hemodynamically slightly compromised patients with mitral stenosis (G-MS, n=13), the mean PAW pressure was 14.2±2.6 mmHg, PBV_PAT-LA was 11.12±2.86 ml/kg, LTV_Ao was 5.68±1.41 ml/kg and PBV_PAT-LA/LTV_Ao ratio was 2.020.58. Between the two groups, LTV_Ao was not statistically significant, whereas the mean PAW pressure, PBV_PAT-LA and PBV_PAT-LA/LTV_Ao> ratio were all significantly increased in G-MS (p<0.05). Neither PBV_PAT-LA nor LTV_Ao correlated with the mean PAW pressure in both groups. From PBV_PAT-LA/LTV_Ao ratio, fluid volume in the intravascular space was greater than that in the extravascular space in both groups. From LTV_Ao, PEWV in G-MS was identical with that in G-N, in spite of the elevated mean PAW pressure. Therefore, even in the patients with mitral stenosis, the interstitium in the lung is kept dry under conditions of the mean PAW pressure below 20 mmHg. The safety factors that prevent pulmonary edema, as evidenced in animal studies, seem to operate effectively in man.

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The effects of fiber direction on the conduction of excitation and the characteristics of both extracellular and intracellular action potentials were examined in isolated dog ventricular muscle preparations. Conduction velocity and amplitude of extracellular potentials during propagation in the direction parallel to the long axis of fibers (longitudinal propagation) were significantly greater than those during propagation in the direction perpendicular to it (transverse propagation). However, the maximum rate of rise and amplitude of intracellular action potential were significantly greater during transverse propagation than during longitudinal propagation. Compared with the transverse propagation, the longitudinal propagation was more susceptible to conduction failure under high extracellular K⁺ concentration, suggesting a lower safety factor of the latter mode of propagation in depolarized cardiac tissue. In contrast, high frequency stimulation caused a greater decrease in the conduction velocity during transverse than longitudinal propagation resulting in augmentation of anisotropic conduction properties. These results suggest that the anisotropic conduction properties of cardiac tissue may play important roles in conduction disturbances leading to arrhythmias under various pathological conditions.

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The effects of respiratory acidosis on ventricular shunt flow and hemodynamics were studied in 20 anesthetized dogs with a ventricular septal defect and a normal pulmonary vascular bed. The interventricular shunt flow was measured directly by using a specially designed electromagnetic flow probe. Respiratory acidosis was produced by hypoventilation and tachypnea with constant minute volume. Hypoxemia was also induced by hypoventilation, but not by tachypea with constant minute volume. Systemic vascular resistance was increased in severe hypoventilation at 100 and 50 ml of tidal volume, and tachypnea at 100 ml of tidal volume. However the increase of pulmonary vascular resistance was observed in only severe hypoventilation: arterial pH 6.9, PaO₂ 24 mmHg, and PaCO₂ 88 mmHg. Left to right ventricular shunt flow and pulmonary blood flow were increased significantly with no change of systemic blood flow in both conditions of respiratory acidosis. The diastolic fraction of shunt flow was increased significantly. These findings indicate that the increase of left to right shunt flow in respiratory acidosis might be one of the risk factors of congestive heart failure for the patients with ventricular septal defect.

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Molsidomine was administered intraduodenally to anesthetized dogs which were instrumented for measurements of aortic and left ventricular (LV) pressures, coronary perfusion pressure, intramyocardial pressure in the subendocardium, and subendocardial and subepicardial myocardial blood flow in the ischemic and non-ischemic regions. The dogs were divided into two groups: group M (n=9) was administered molsidomine (0.2 mg/kg), group S (n=10), saline only. Maximum LV systolic pressure decline was 20% in group M and 3% in group S (p<0.05). Maximum LV end-diastolic pressure decline was 63% and 35% in groups M and S, respectively (p<0.05). There was no difference between mean aortic pressure and coronary perfusion pressure between the two groups. The subepicardial blood flow in the ischemic region was decreased (-23% in group M vs 5% in group S; p<0.05), but subendocardial blood flow in the ischemic region increased only slightly in group M. The ratio of subendocardial to subepicardial blood flow increased at 15 and 30 min after administration of molsidomine in the ischemic area (67% in group M vs -10% in group S; p<0.050. but did not show any change in the non-ischemic region. Intramyocardial pressure at systole did not show any change but it decreased at end-diastole, (-32% in group M vs -7% in group S; p<0.05). Thus molsidomine redistributed the myocardial blood flow from the subepicardium to the subendocardium and from the non-ischemic to the ischemic region. This redistribution was associated with a reduction in both LV end-diastolic pressure and intramyocardial pressure at end-diastole.

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An analysis was made of 91 cases of infective endocarditis (IE) with regard to causative organisms and their sensitivities to various antibiotics, the clinical features of the disease, the laboratory test results and other items were important in establishing a diagnosis of IE. The number of cases of IE has shown a tendency to increase in recent years, particularly in the number of elderly patients, and the ratio of total cases consisting of prosthetic valve endocarditis (PVE) has shown a sharp increase. The most common causative organism is still Streptococcus viridans, but there has been an increase in the incidence of IE due to benzyl-penicillin-resistant strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis and other fastidious organisms. The percentage of underlying diseases represented by combined valvular diseases has been increasing, while the primary known cause of the infection of IE was dental treatments. A positive value for CRP, an accelerated value for ESR, leukocytosis, anemia, a decrease in serum Fe, a positive value for RA-T, were all parameters which showed a high correlation with IE, and these should be useful in establishing the diagnosis of IE. The use of cardioechography to detect cardiac vegetation is important in relation to establishing the diagnosis and prognosis of IE, and the evaluation of the therapeutic results.

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Out of the 10 patients with infective endocarditis (IE) at Kawasaki Municipal Hospital, 8 had IE due to streptococcus viridans. Out of 8 patients with streptococcus IE, 6 were successfully treated with benzyl penicillin alone or in combination with kanamycin. One patient was cured with cephaloridine. Two hundred and thirty IE patients admitted to hospitals at Kantou District were also studied. Ninety nine of 116 patients with streptococcus viridans IE were successfully treated with potentially active in vitro against streptococcus viridans. Out of 16 staphylococcus IE patients, 11 patients died. Eight patients died within 8 days from the beginning of the antibiotic administration. Out of 7 enterococcal IE patients, 5 were successfully treated with ampicillin alone or in combination with aminoglycosides. Forty three patients were diagnosed as IE despite negative blood culture. The echo cardiogram showed 23 patients had vegetation. Benzyl penicillin was given to 28 patients and 23 were cured. Out of 9 patients with culture negative IE treated with ampicillin, 8 were cured. Four patients were successfully treated with cephems.

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Problems and limitations of medical management for infective endocarditis were studied and surgical indications were discussed based on the retrospective analysis of 55 episodes. Since perioperative complications still occur during highly active infection, antibiotic treatment was suggested as the primary management. Intractable or progressing heart failure appeared to be a definite indication for emergency surgery, but medical therapy was recommended for mild to moderate heart failure. For uncontrolled infection of more than one month duration despite the best available antibiotics, surgical debridement of the infected tissue was indicated. Occurrence of peripheral or fatal emboli was difficult to predict from clinical features and echocardiogram and therefore presented a therapeutic dilemana. Since major or fatal emboli frequently occurred during highly active infection, early initiation of effective antibiotic therapy was considered to be of primary importance. Demonstration of vegetation by echocardiography alone did not seem to justify urgent surgery. In addition, disseminated intravascular coagulation appeared to be a serious complication and thus sedimentation rate should be followed carefully. In the healed stage, prophylactic surgery seemed unnecessary for prevention of recurrent infection or embolization, as they were relatively rare.

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The clinical manifestations, infective microorganisms, underlying diseases, complications and prognosis of infective endocarditis (IE) were studied in 17 current patients. Data were compared with 101 previous cases reported in Japan. Most patients with IE (110/118=93.2%) had underlying heart diseases. IE was noted most often in patients with ventricular septal defect (VSD) and tetralogy of Fallot. The incidence of post operative endocarditis was high (29.4% in the present series and 9.0% in the overall series), too. Streptococcus viridans, Staphylococcus aureus and GNB were the most common etiologic agents with incidences of 28.8% (34/118), 25.4% (30/118) and 9.3% (11/118), respectively. Almost half of the deaths from IE were caused by s. aureus. The mortality was 11.9% (14/118) in both series. The death rate from candida albicans were 100% from s. aureus 33.3% (10/30) and from str. viridans 5.9% (2/34) in both series. Culture negative patients accounted for 11.9% (14/118) in both series. Complications which did not involve the valves were noted in one patient with cerebral emboli and in two patients with pulmonary infarction in the present series. Cerebral emboli phenomena were seen 8 cases of the overall series, 4 of whom died.

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Persistent fever during active-phase IE is an indication for surgical treatment in the light of the causative organism and the underlying disease. To counter worsening hemodynamics, surgery may be the only feasible way. surgery is performed when the patient does not respond to vasodilators and he shows an FS of less than 25%. The introduction of translocation provides a solution for the treatment of active IE. Lesions, vegetations more than 5 mm in diameter, periannular abscess, and mycotic aneurysm that could never be overlooked by two-dimensional echocardiography may hasten the early-stage decision of ways to treat IE.

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