Relationship between aortic valve stenosis and the hemodynamic pattern in the renal circulation, and restoration of the flow wave profile after correction of the valvular defect.

OBJECTIVE: The index of maximal systolic acceleration ([AImax]: maximal systolic acceleration of the Doppler waveform divided by peak systolic velocity) shows diagnostic accuracy in screening of renal artery stenosis. This study aimed to determine whether an upstream factor of resistance, such as aortic valve stenosis (AVS), can affect Doppler parameters detected in the peripheral arteries. METHODS: In this prospective study, we measured the AImax in non-stenotic renal interlobar arteries of 62 patients with AVS. Patients were divided into three groups on the basis of severity of valvulopathy as follows: mild-to-moderate AVS (M-AVS; n = 24), intermediate AVS (I-AVS; n = 15), and severe AVS (S-AVS; n = 23) based on Nishimura's criteria. RESULTS: The AImax in the renal parenchymal arteries was significantly lower in the S-AVS group (8.9 ± 3.6 s-1) than in the M-AVS (15.3 ± 3.8 s-1) and I-AVS groups (16.7 ± 5.2 s-1). The AImax was positively correlated with the aortic valve area and inversely correlated with the tranvalvular aortic pressure gradient. After aortic valve replacement, the AImax significantly increased from 10.7 ± 4.0 s-1 at baseline to 19.3 ± 4.4 s-1. CONCLUSIONS: Proximal resistance can lead to diagnostic bias of Doppler parameters that are applied in the diagnosis of peripheral vasculopathies, particularly in renal artery stenosis.

Valvular and/or Non-valvular Aortic Pathology Can Bias the Ultrasonographic Diagnosis of Renal Artery Stenosis.

Renal artery stenosis (RAS) has been shown to cause a reduction in the index of maximal systolic acceleration (AImax: the maximal acceleration of flow waveform in early systole divided by the peak systolic velocity) of blood in the renal interlobar arteries, caused by local dampening of the pulse wave. In previous studies, AImax demonstrated diagnostic accuracy in terms of negative predictive value, which is useful for screening, but had a relatively low specificity. We hypothesized that an upstream focal resistance, such as an aortic stenosis or aneurysm, could act in the same way as RAS, thus generating false positives in non-stenotic kidneys. We studied 226 patients who underwent a complete protocol for RAS screening. AImax was 6.2 ± 2.9 s-1 and 13.4 ± 3.5 s-1 (mean ± standard deviation) in stenotic and non-stenotic kidneys, respectively. Diagnostic accuracy of ultrasonography with respect to the benchmark of renal computed tomography or magnetic resonance angiography (significant RAS cutoff ≥50%) resulted in 97% sensitivity, 94% specificity and a negative and positive predictive value of 99% and 55%, respectively. Using logistic regression for unexpectedly low AImax in non-stenotic kidneys (AImax cutoff ≤ 9.0 s-1), aortic pathology, such as aortic valve stenosis or aortic arch dilation (as assessed by echocardiography), was found to be the only significant predictor (Χ2 = 33.8, p < 0.0001) of false positive cases compared with clinical and hemodynamic variables. We concluded that the aortic valvular and non-valvular pathology can act as a proximal resistance that can attenuate the Doppler flowmetric parameters, which explore the flow waveform in the renal parenchymal arterial circulation, thus mimicking the presence of a focal resistance in the peripheral vascular region explored.

A case report of hyponatremia after surgery for Conn's adenoma.

Primary aldosteronism (PA), also known as Conn's syndrome, is a frequent cause of secondary hypertension. If PA is due to a documented unilateral adrenal adenoma, adrenalectomy is the treatment of choice. Endocrine Society guidelines suggest monitoring potassium after adrenalectomy, while there is no mention of sodium disorders after surgery. Here we report the case of a patient with Conn's syndrome who developed hyponatremia after surgery. This was an unexpected event in the course of the treatment, which sheds light on the fact that low levels of aldosterone strongly influence sodium concentration, and advises clinicians to monitor sodium after adrenalectomy.

Gait and apathy as relevant symptoms of subcortical vascular dementia.

BACKGROUND: Subcortical vascular dementia relates to small-vessel disease and hypoperfusion, resulting in focal and diffuse ischemic white matter lesions. The main target of the disease are the frontal subcortical neural networks. There is no clinical standard definition of the pathology, on the contrary, everyday clinical practice suggests dominant behavioral alterations and dysexecutive syndrome. METHODS: The aim of this study was to investigate gait disorders, behavioral alteration, and drug intake of a subcortical population with dementia (n = 1155). A complete neuropsychological examination was conducted at baseline and every 6 months, and the results were compared. RESULTS: Our data suggest that there is a significant increment in apathy levels and a dramatic decrease in gait and equilibrium control in the patients examined during follow-up. CONCLUSION: Subcortical vascular dementia may be associated with gait and balance alteration and apathy per se; we suggest to implement clinical data with these major aspects.