Mechanisms and management of diuretic resistance in congestive heart failure.

Diuretic drugs are used almost universally in patients with congestive heart failure, most frequently the potent loop diuretics. Despite their unproven effect on survival, their indisputable efficacy in relieving congestive symptoms makes them first line therapy for most patients. In the treatment of more advanced stages of heart failure diuretics may fail to control salt and water retention despite the use of appropriate doses. Diuretic resistance may be caused by decreased renal function and reduced and delayed peak concentrations of loop diuretics in the tubular fluid, but it can also be observed in the absence of these pharmacokinetic abnormalities. When the effect of a short acting diuretic has worn off, postdiuretic salt retention will occur during the rest of the day. Chronic treatment with a loop diuretic results in compensatory hypertrophy of epithelial cells downstream from the thick ascending limb and consequently its diuretic effect will be blunted. Strategies to overcome diuretic resistance include restriction of sodium intake, changes in dose, changes in timing, and combination diuretic therapy.

Giant cell (temporal) arteritis diagnosed following upper limb claudication.

Giant cell arteritis or temporal arteritis occurs almost exclusively in people over 50 years of age. It classically presents with new onset temporal headache, scalp tenderness and jaw claudication. Proximal muscle pain and stiffness is often present because of frequent association with polymyalgia rheumatica. In most cases, the erythrocyte sedimentation rate is markedly elevated. Uncommon presentations include systemic symptoms and symptoms related to large artery involvement. We report a case of giant cell arteritis without symptoms related to the temporal artery, diagnosed angiographically following upper limb claudication and confirmed by temporal artery biopsy.

Small and large artery elasticity indices in peripheral arterial occlusive disease (PAOD).

In peripheral arterial occlusive disease (PAOD), arterial compliance of the central arteries has been reported to be reduced. It is, however, not clear whether, in PAOD, decreased arterial compliance is also accompanied by similar changes in the peripheral arteries. Therefore the aim of the study was to determine the large (C1) and small (C2) artery elasticity indices in PAOD and their relations to its well-accepted characteristics (ankle-brachial index, ABI; pulse pressure, PP; absolute claudication distance, ACD). A total of 43 patients with PAOD (mean age 68 +/- 9 years; ABI of the limiting leg 0.65 +/- 0.14; SBP (systolic blood pressure) 149 +/- 20 mmHg, and ACD 488 +/- 187 m) were enrolled as well as 16 control subjects of comparable age (69 +/- 4 years) and blood pressure (SBP 147 +/- 27 mmHg). All subjects underwent non-invasive pulse wave analysis in order to determine arterial compliance of the aorta and major side branches (C1) and of the distal circulation (C2), using a modified Windkessel model. In PAOD, both C1 (1.41 +/- 0.56 ml/mmHg) and C2 (0.023 +/- 0.012 ml/mmHg) were comparable to values in an age and blood pressure-matched control group (C1, 1.25 +/- 0.66 ml/mmHg; C2, 0.027 +/- 0.008 ml/mmHg). C1 was significantly correlated with ACD (r = 0.36, p = 0.02), PP (r = -0.33, p < 0.02) and only borderline with ABI (r = 0.28, p = 0.07). C2 was correlated with PP (r = -0.38, p < 0.01), ABI (r = 0.36, p < 0.02) but not with ACD. Large (C1) and small (C2) artery elasticity indices in PAOD were decreased but comparable to values in an elderly group with isolated systolic hypertension. Moreover, C1 and C2 correlated with markers (ABI and PP) of severity of vascular disease.