Myocardial tissue pH and temperatures (MT) were continuously measured in dogs on total cardio-pulmonary bypass (CPB) after acute distal coronary artery occlusion. Measurements were performed in a collateralized area with myocardial blood flow (MBF) ranging from 20 to 80 ml/100 g-min (microspheres). Immediately after coronary artery occlusion the aorta was clamped and the heart perfused with a cardioplegic solution (Bretschneider HP, 41 ml/kg, 4 degrees C). Prolonged regional fibrillation was observed and MT fell to 20 degrees C in 10 min in the low perfusion area (LPA) and in 2 min in the control area (CA). Whereas MTs were practically identical 15 min after termination of cardioplegic perfusion the magnitude of H+ accumulation continued to be greater in the LPA. During blood reperfusion with the coronary snare released MBF was significantly lower in the LPA as opposed to the CA indicating a microcirculatory derangement. Accordingly the bipolar ECG revealed signs of regional ischemia even after 30 min of reperfusion. We conclude that myocardial protection may be inadequate in areas located distal to coronary occlusion. This is true not only in cases of acute severe ischemia but also when collateral resistance is sufficiently high to impede the flow of cold viscous cardioplegic solutions. Results derived from intermittent MT measurements may be erroneous because intramyocardial heat equilibration may mask the inhomogeneous cardioplegic perfusion.

Abstract. Successful maintenance therapy with mycophenolate mofetil (MMF) 2 g/d and low-dose oral corticosteroids (OCS) over a period of 15 mo was given to patients with Wegener's granulomatosis (WG) (n = 9) and microscopic polyangiitis (MPA) (n = 2). All patients had severe generalized disease with pauci-immune necrotizing glomerulonephritis and received standard induction therapy with oral cyclophosphamide and OCS for a mean of 14 wk until remission was achieved. Of 11 patients, only one WG patient relapsed in the 14th month of maintenance therapy. Maintenance therapy with MMF was able to further reduce grumbling disease activity as measured by the Birmingham vasculitis activity score (BVAS2) and proteinuria that were still present by the end of induction therapy. OCS could be reduced to a median daily dose of 5 mg and discontinued in three patients. Possible drug-related adverse effects were transient and included abdominal pain, respiratory infection, diarrhea, leukopenia, and a cytomegalovirus-colitis in one patient that was successfully treated with ganciclovir. It is concluded that MMF in combination with low-dose OCS is well tolerated and effective for maintenance therapy of WG and MPA. Long-term treatment with MMF in these diseases is attractive because of its low toxicity. MMF will have to be studied further and compared with cyclophosphamide or azathioprine maintenance therapy in randomized trials.

Hypertension is common in hemodialyzed patients and constitutes an important cardiovascular risk factor. Fluid retention, inappropriate stimulation of the renin-angiotensin system, sympathetic overactivity and changes of vessel wall structure have been shown to be important factors in its pathogenesis. It has been claimed that hemofiltration permits a better control of hypertension in the interdialytic interval, although the evidence is not perfectly convincing; blood pressure tends to be lower with continuous ambulatory peritoneal dialysis. While fluid withdrawal and – within certain limits – adjustment of dialysate sodium concentration constitutes a primary line of therapy, antihypertensive medication is necessary in approximately 20% of patients. Specific problems with dialysis patients are cumulation of drugs (some cardioselective beta-blockers, alpha-methyldopa, captopril), altered dose-response relationship (diuretics) and particularly interaction with cardiovascular stability during fluid withdrawal.

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