Correlation between systolic transvalvular flow and proximal aortic wall changes in bicuspid aortic valve stenosis.

OBJECTIVES: The purpose of this study was to analyse the correlation between preoperative systolic transvalvular flow patterns and proximal aortic wall lesions in patients undergoing surgery for bicuspid aortic valve (BAV) stenosis. METHODS: A total of 48 consecutive patients with BAV stenosis (mean age 58 ± 9 years, 65% male) underwent aortic valve replacement (AVR) ± proximal aortic surgery from January 2012 through February 2013. Preoperative cardiac phase-contrast cine magnetic resonance imaging (MRI) assessment was performed in all patients in order to detect the area of maximal flow-induced stress in the proximal aorta. Based on these MRI data, two aortic wall samples (i.e. area of the maximal stress (jet sample) and the opposite aortic wall (control sample)) were collected during AVR surgery. Aortic wall changes were graded based on a summation of seven histological criteria (each scored from 0 to 3). Histological sum score (0-21) was separately calculated and compared between the two aortic samples (i.e. jet sample vs control sample). RESULTS: An eccentric transvalvular flow jet hitting the proximal aortic wall could be identified in all 48 (100%) patients. The mean histological sum score was significantly higher in the jet sample vs control sample areas of the aorta (i.e. 4.1 ± 1.8 vs 2.2 ± 1.5, respectively) (P = 0.02). None of the patients had a higher sum score value in the control sample. CONCLUSIONS: Our study demonstrates a strong correlation between the systolic pattern of the transvalvular flow jet and asymmetric proximal aortic wall changes in patients undergoing AVR for BAV stenosis.

Cryptogenic transient ischemic attack after nose blowing: association of huge atrial septal aneurysm with patent foramen ovale as potential cause.

Association of atrial septal aneurysm (ASA) with patent foramen ovale (PFO) is considered an important risk factor for cardioembolism frequently forwarding paradoxical embolism in patients with cryptogenic or unexplained cerebral ischemic events. We herein describe the case of a 69-year-old male patient reporting uncontrolled movements of the right arm due to a muscle weakness, slurred speech, and paresthesia in the oral region some seconds after he had blown his nose. These neurological symptoms had improved dramatically within a few minutes and were completely regressive at admission to our hospital about two hours later. On transesophageal echocardiography (TEE) a huge ASA associated with PFO was detected. Diagnosis of the large-sized ASA was also confirmed by cardiac magnetic resonance imaging. Due to the early complete recovery from his neurological symptoms, the patient was diagnosed with a transient ischemic attack (TIA). After nine days he was discharged in a good clinical condition under the treatment with oral anticoagulation. It is concluded that in cryptogenic or unexplained stroke or TIA TEE should always be performed to rule out ASA and PFO as potential sources for paradoxical embolism in those inconclusive clinical situations.

Determination of renal porphyrin handling in rats suffering from different kinds of chronic renal failure (CRF): uranyl nitrate (UN) induced fibrosis or 5/6-nephrectomy (5/6NX).

The renal handling of porphyrins is reported to be a sensitive marker for chronic renal failure (CRF) for two reasons: heme is synthesised in proximal tubules and porphyrins are reabsorbed in the renal proximal tubule by apical peptide transporter PEPT 2. Two different models of CRF in female Wistar rats have been used for investigation of renal porphyrin handling: (1) single administration of uranyl nitrate (UN; 0.5 mg/100 g b.wt.) and (2) 5/6 nephrectomy (5/6NX). Renal clearance experiments were performed at weeks 2 and 10 after the onset of CRF. The concentrations of porphyrin intermediates (uroporphyrin I and III, coproporphyrin I and II, heptaporphyrin, and pentaporphyrin) were measured by HPLC with fluorescence detection. Both after UN and 5/6NX a significant reduction of body weight occurred. The kidney weight was enhanced 2 weeks after UN compared to controls (+31%). After 5/6NX, the weight of the remnant kidney was 44% (2nd week) and 140% (10th week) higher compared to one control kidney. Urine volumes and GFR were significantly reduced at week 2 and 10 after 5/6NX, but at week 10 after UN values were comparable to controls. Two weeks after UN and 5/6NX the concentrations of heptaporphyrin was moderately decreased in renal tissue whereas after 10 weeks the concentrations of most porphyrins were increased in the kidney. The plasma levels of free porphyrins were only slightly enhanced (week 2). The renal excretion of porphyrins was initially slightly reduced in both models, whereas it increases 10 weeks after UN, but it remained reduced 10 weeks after 5/6NX. UN induces tubulointerstitial fibrosis including atrophic glomeruli, whereas 5/6NX was characterized by distinct proteinuria, dilated tubules containing hyaline casts. A modulation of porphyrin metabolism in the kidney seems first of all to be responsible for UN effect on renal porphyrin handling. Summing up the 5/6NX results, both reduction in intact renal tissue mass and a modification of enzymes involved in heme biosynthesis by uraemic toxins are responsible for accumulation of porphyrins in renal tissue. After 5/6NX reduced excretion of porphyrins into urine and enhanced porphyrin concentrations in the kidney indicate more a damage of renal porphyrin biosynthesis than changes in their reabsorption.