Atrial and brain natriuretic peptides derived from the heart regulate the circulatory system in healthy humans and in patients with heart failure by virtue of their potent renal excretory, vasodilatory, and anti-reninaldosterone properties. The value of enhancing these biologically active properties for the treatment of heart failure has been demonstrated by clinical trials. Measurement of plasma levels of these natriuretic peptides is an important tool in the prediction of long-term survival in patients with heart failure. Nitric oxide derived from the endothelium exerts vasodilatory effects and inhibits vascular smooth muscle cell proliferation and platelet aggregation. Reduced production of nitric oxide may limit the dilation of small arteries supplying nutritive blood flow to muscle during exercise, and may therefore be an important factor in predisposition towards and progression of coronary heart disease. Excessive myocardial nitric oxide production provoked by cytokine-induced nitric oxide synthase may reduce heart muscle contractility and induce cardiac cell damage. It may thus be pathophysiologically related to cardiac systolic dysfunction and ventricular remodeling in some forms of heart failure. Endothelin receptor inhibition in patients with heart failure has been shown to increase cardiac output while reducing the systemic and pulmonary vascular resistance. This suggests that inhibition of the biological effects of the peptide may offer a new strategy for the management of cardiovascular disease. Adrenomedullin is a newly discovered potent vasodilatory peptide with mild diuretic and positive inotropic properties, enhancement of which may potentially be useful for treating hypertension and heart failure. These biological active agents produced from the cardiovascular system are now regarded as important autocrine, paracrine, and circulating factors in the regulation of cardiovascular functions and structural change. It follows that measurement and modulation of their properties may provide new strategies for the treatment and diagnosis of cardiovascular disease.

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We examined the clinical limitations of reperfusion therapy (RT) for acute myocardial infarction (AMI). The 1135 consecutive patients admitted to our institution from 1983 to 1993 were divided into two groups (Group RT, n=552 and Group C (Conservative Therapy), n=583). Each group was classified into older (or elderly) patients (aged≥75 years) and younger patients (aged <75 years). The patients in Group RT had significantly lower in-hospital mortality than Ggroup C (19.7% vs 11.4%, p<0.01), however there was no significant difference in the incidence of in-hospital death in the elderly between Group RT and C (23.1% vs 29.4%). Patients with complicattions from cardiogenic shock in Group RT had significantly lower mortality than in Group C (51.6% vs 82.0%, p<0.01), but it was still high (58.6%) in the elderly. There were no significant differences in causes and the age distribution of in-hospital deaths in Groups RT and C. Of the 63 patients who died during hospitalization in Group RT, 37 patients (59%) experienced pump failure caused by cardiogenic shock and 32 patients (51%) were more than 75 years old.
These data showed the clinical limitations of RT for elderly patients and patients with cardiogenic shock in AMI.

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The arterial ketone body ratio (AKBR: arterial acetoacetate/β-hydroxybutyrate ratio) reflects the hepatic mitochondrial redox potential. It is frequently measured to evaluate hepatic dysfunction and multiple systems organ failure. We compared AKBR to the hepatic venous ketone body ratio (HKBR) to carify the doubt which exist as to whether AKBR really represents the ketone body ratio in hepatic venous blood.
This study was approved by our institutional review board and informed consents was obtained from thirteen consecutive patients undergoing hepatic resection surgery. After anesthetic induction, a radial arterial cannula was placed and 7.5-Fr fiberoptic catheters (OpticathModel P7110-EH, Oximetrix) were inserted into the pulmonary artery and the hepatic vein. Anesthesia was maintained with nitrous oxide and oxygen with isoflurane. We measured acetoacetate and β-hydroxybutyrate in each patient at one hour intervals while hepatic venous hemoglobin oxygen saturation was stable for a total of 80 sampling points. The results were evaluated with linear regression analysis and a p value of 0.05 or less was considered significant.
AKBR was significantly correlated to HKBR (r=0.880 (p<0.01), where AKBR=0.596×HKBR+0.119). On the linear regression line, HKBR was smaller than AKBR when AKBR was below 0.29, HKBR was larger than AKBR when AKBR was above 0.29. These results show that, the differences between HKBR and AKBR largely depend on the value of HKBR. The differences may be related to the ratio in which hepatic venous blood mixes with inferior vena cava blood. It is also possible that the differences were related to the clearance of ketone bodies which may vary depending on the value of HKBR.
These results were obtained during liver resection surgery, but may be applicable in general for the clinical evaluation of liver dysfunction associated with multiple systems organ failure.

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A 36 year-old male came in complaining of severe back painand then went into shock. ECG revealed poor anterior R progression without any ST-T changes. The left ventricular wall was hypokinetic on echocardiography. The chest X-ray showed pulmonary edema and the thoraco-abdominal CT revealed a right adrenal tumor. A tentative diagnosis of acute myocarditis was made.
The patient was markedly unstable hemodynamically showing severe hypotension which responded poorly to increased doses of catecholamines. This was followed by normal blood pressure requiring no pressor agents. Intraaortic balloon pumping (IABP) was started when systolic blood pressure remained at 70mmHg. The state of shock persisted and systolic blood pressure fell to 60mmHg. We put the patient on extra-corporeal lung and heart assist (ECLHA). The patient's hemodynamic state stabilized on ECLHA but started to show periodic hypertensive attacks (>200mmHg). Catecholamine concentration was found to be abnormally high.
A diagnosis of pheochromocytoma of the right adrenal gland was made. The tumor was resected surgically without complications, but an ECG two weeks later showed q-waves and negative t-waves. The possibility of micro-myocardial damage cannot be ruled out.
We believe ECLHA may be an effective option to support the cardiovascular system during catecholamine crisis in patients with pheochromocytoma. ECLHA may make it possible to save patient in severe shock and to prevent catecholamine-induced myocardial damage by reducing catecholamine dosage during ECLHA.

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