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Luca S De Santo

Publications and source records attributed to Luca S De Santo.

At least 19 recordsLinked to original sources
PubMed2006

Echocardiographic anatomy of ascending aorta dilatation: correlations with aortic valve morphology and function.

BACKGROUND: Different anatomical forms of proximal aortic dilations associated with aortic valve disease can be distinguished by echocardiography. Differences in the anatomy could reflect different pathogeneses and need for different therapeutic approaches. The present study assessed the clinical features associated to each anatomical form, particularly focusing on the relations with valve morphology and function. METHODS: Trans-thoracic and trans-esophageal echocardiography reports of 552 adult patients (mean age 60.4+/-12.8 years; 379 male) with mild to severe proximal aorta dilation were reviewed. The relationships between the anatomy of aorta dilatation (distinguished into "root type" dilatation, with maximal enlargement at the sinuses, and "mid-ascending type", with maximal diameter at the mid-ascending tract) and aortic valve morphology (tricuspid/bicuspid) and function (normal/stenosis/regurgitation) were assessed. The relations with other clinico-echocardiographic variables were also tested in univariate and multivariate analysis. RESULTS: A "root type" dilatation was found in 4.9% tricuspid patients with stenosis, 32.3% with regurgitation, 22.5% with normal valve function (p=0.018). Dilatation prevailed at the mid-ascending tract in patients with bicuspid aortic valve, irrespective of valve function (stenotic: 92.9%, regurgitant: 87.9%, normal: 94.3%; p=0.23). Predominant root involvement was significantly more prevalent in male patients (24.8% versus 5.2% in females; p<0.001). In multivariate analysis, predominant aortic valve regurgitation (OR=1.83; p=0.028) independently predicted root site, while predominant aortic valve stenosis (OR=3.70; p=0.001), bicuspidity (OR=2.90; p=0.005) and female sex (OR=6.10; p<0.001) predicted mid-ascending site. CONCLUSIONS: Pathogenetical considerations arise from the evidence of preferential mid-ascending localization of bicuspid-associated aortic dilatations. This finding is consistent with previous studies on bicuspid valve models revealing a wall stress overload beyond the sino-tubular ridge.

Aorta↗
PubMed2006

Aortic arch surgery: thoracoabdominal perfusion during antegrade cerebral perfusion may reduce postoperative morbidity.

BACKGROUND: This study aimed to assess the results of the introduction of thoracoabdominal perfusion (TAP) in the surgical strategy for aortic arch replacement with cerebral protection. METHODS: Two hundred two arch procedures performed with moderate hypothermia (22 degrees to 26 degrees C) and antegrade cerebral perfusion (ACP) were the objects of retrospective investigation. Acute type A dissection was the indication in 164 patients, aortic aneurysm in 38. In 80 patients, during ACP, the thoracoabdominal aorta was perfused either in an antegrade fashion through proximal descending aorta endoluminal cannulation (in 62 dissections), or retrograde through femoral artery cannulation with proximal descending aorta endoluminal occlusion (in 18 aneurysms). Hospital mortality and morbidity rates were compared between the two treatments (group A: ACP only, 122 patients; group B: ACP plus TAP, 80 patients) and the underlying aortic disease (dissection/aneurysm) was stratified. RESULTS: Cerebral perfusion (p = 0.008) and cardiopulmonary bypass times (p = 0.035) were significantly longer in group B. No complication related to the TAP technique was observed in group B. Overall hospital mortality was 12.9%, without significant difference between groups. No differences were found in terms of permanent neurological dysfunction between groups A (9.3%) and B (9.1%; p = 0.58). Group B patients showed lower rates of respiratory failure (18.2% versus 30.5% in group A; p = 0.038), shorter mechanical ventilation times (18.1 +/- 26 hours versus 57.9 +/- 70.1; p < 0.001) and lower incidence of acute renal failure (6.5% versus 18.6%; p = 0.012). Shorter intensive care and hospital stays were observed in group B (p = 0.02). CONCLUSIONS: The adjunction of TAP to ACP was associated with lower rates of end-organ complications, even in more extensive and time-consuming procedures.

Aortic Dissection↗
PubMed2006

Spatial patterns of matrix protein expression in dilated ascending aorta with aortic regurgitation: congenital bicuspid valve versus Marfan's syndrome.

BACKGROUND AND AIM OF THE STUDY: Aortic wall stress has been shown to increase locally at the convex aspect of the ascending tract when axial root motion is increased, as occurs in aortic valve regurgitation. The study aim was to assess the expression of extracellular matrix (ECM) proteins involved in stress-induced vascular remodeling in the convexity and the concavity of dilated ascending aortas with aortic valve regurgitation. METHODS: Aortic wall specimens, harvested at the convexity and concavity of eight dilated ascending aortas with severe aortic valve regurgitation underwent morphometry, Western blot, RT-PCR and confocal immunohistochemistry. Five patients (group A) had congenital bicuspid aortic valve (BAV), and three (group B) had Marfan's syndrome. Specimens from the aorta of three multi-organ donors served as controls. RESULTS: At morphometry, medial degeneration was more severe in the convexity than in the concavity, especially in group A. Western blot, RT-PCR and immunohistochemistry disclosed an asymmetric pattern in the expression of some ECM proteins (laminin, tenascin, fibronectin). Fibronectin was increased in the convexity of both groups compared to controls at Western blot. Immunohistochemistry confirmed this pattern only in BAV. Higher levels of tenascin were found in the convexity in group A. The laminin content was greater in the concavity than in the convexity of both groups, but in group B the type of laminin was different, with the beta2 chain particularly expressed, and almost absent in non-Marfan patients. Type I and type III collagens were more markedly reduced in the convexity than in the concavity in BAV. In group B, type I collagen was decreased and type III increased, but without any significant difference between the two aspects of the aorta. CONCLUSION: A tissue remodeling response to valve disease-related wall stress may underlie aortic dilatation with BAV regurgitation. Although morphometry showed similar changes in Marfan aortas, molecular investigations differentiated this condition, qualitatively, from BAV.

Adult↗
PubMed2005

Treatment of extensive ischemic cardiomyopathy: quality of life following two different surgical strategies.

OBJECTIVE: To review outcomes and quality of life following two surgical strategies for severe left ventricular dysfunction due to ischemic dilated cardiomyopathy. METHODS: Hospital and follow-up records of 111 patients with extensive ischemic cardiomyopathy (mean age 57.3+/-8.4) referring to our institution between January 1996 and December 2003 were reviewed. Group A included 42 patients (mean age 62.4+/-7.9) with morphological and functional cardiac parameters allowing for ventricular restoration (including endoventricular circular patch plasty, coronary artery by-pass grafting, and, when needed, mitral surgery). Group B included 69 patients (mean age 54.3+/-7.2), undergoing cardiac transplantation. Hospital mortality, treatment-related late mortality, incidence of cardiac events, freedom from cardiac failure, freedom from hospital re-admission, functional recovery at follow-up (3075.2pts/months; 100% complete) and quality of life (WHOQOL test) were assessed. RESULTS: Hospital mortality was 19% in group A and 8.7% in group B (P=0.143). No treatment-related late deaths were observed in group A, while six deaths (9.5%) occurred in group B (P=0.063). Incidence of cardiac events was comparable. At 60 months, freedom from cardiac failure was 93.5+/-0.04 and 86.2+/-0.05%, respectively (P=0.23), freedom from hospital re-admission was 93.5+/-0.04 and 61.3+/-0.07% (P=0.002). Exertion dyspnea was present in 40% patients in group A versus 13% in group B (P=0.006). WHOQOL test showed a satisfying quality of life in both groups, although patients undergoing restoration reached higher scores in the psychological and social domains. CONCLUSIONS: Selected patients with ischemic cardiomyopathy, potentially eligible for transplantation, can be managed by ventricular restoration. In those patients post-operative quality of life is satisfactory, with comparable survival and low risk of re-hospitalization.

Adult↗
PubMed2005

Left ventricular mass regression after aortic valve replacement with 17-mm St Jude Medical mechanical prostheses in isolated aortic stenosis.

OBJECTIVE: The present study investigated the outcomes of aortic valve replacement with 17-mm mechanical prostheses in patients with isolated aortic stenosis. METHODS: Between January 1997 and January 2003, 35 patients (mean age, 63.4 +/- 17 years; median age, 70 years; age range, 16-84 years) underwent isolated aortic valve replacement with a 17-mm St Jude Medical Hemodynamic Plus (16 [45.7%] patients) or a St Jude Medical Regent prosthesis (19 [54.3%] patients). The paired Student t test or the paired Wilcoxon rank sum test were used to compare preoperative with follow-up echocardiographic measurements. RESULTS: Thirty-two (91.4%) patients were female, mean height was 154.4 +/- 8.3 cm, mean weight was 62.2 +/- 9.2 kg, and mean body surface area was 1.59 +/- 0.13 m 2 . The preoperative average New York Heart Association class was 2.8 +/- 0.8. The mean preoperative left ventricular mass index was 135.2 +/- 31 g/m 2 . Preoperative echocardiography showed an average gradient of 65.7 +/- 19.2 mm Hg (mean) and 103.6 +/- 30.7 mm Hg (peak) and a mean indexed effective orifice area of 0.40 +/- 0.1 cm 2 /m 2 . Echocardiographic follow-up time averaged 28.2 +/- 22.7 months (range, 13-72 months). Follow-up was 100% complete (1131.7 patient-months). Hospital mortality was 8.6% (3 patients). Actuarial 5-year survival was 94.7%. The mean postoperative New York Heart Association class was 1.13 +/- 0.34 ( P < .001), with 27 (87.1%) patients in class I and 4 patients in class II. A significant regression of the indexed left ventricular mass was found (postoperative mean value, 107.8 +/- 22.8 g/m 2 ; P < .0001), despite a mean indexed effective orifice area of 0.67 +/- 0.14 cm 2 /m 2 (median, 0.66 cm 2 /m 2 ). CONCLUSIONS: Selected patients with aortic stenosis can experience satisfactory clinical improvement and significant indexed left ventricular mass regression after aortic valve replacement with modern small-diameter bileaflet prostheses.

Adolescent↗
PubMed2005

Different patterns of extracellular matrix protein expression in the convexity and the concavity of the dilated aorta with bicuspid aortic valve: preliminary results.

OBJECTIVE: This study aimed to assess extracellular matrix protein expression patterns at the convexity (right anterolateral wall) and the concavity of the dilated ascending aorta in patients with bicuspid aortic valve disease. METHODS: Aortic wall specimens were retrieved from the convexity and the concavity in 27 bicuspid aortic valve patients (12 with stenosis and 15 with regurgitation) and 6 heart donors (controls). Morphometry, immunohistochemistry, Western blot, and polymerase chain reaction were performed, focusing on matrix proteins involved in vascular remodeling. RESULTS: Type I and III collagens were significantly decreased in bicuspid-associated dilated aortas versus controls (P < .001), particularly at the convexity (P < .05 vs concavity). Expression of messenger RNA for collagens was lower than normal only in the regurgitant subgroup. At immunohistochemistry, proteins whose overproduction has been demonstrated in response to abnormal wall stress, such as tenascin and fibronectin, were more expressed in the convexity than in the concavity, especially in the stenosis subgroup. Tenascin, which is produced by smooth muscle cells in the synthetic phenotype, was nearly undetectable in controls. Fewer smooth muscle cells (stenosis, P = .017; regurgitation, P = .008) and more severe elastic fiber fragmentation (P = .029 and P < .001) were observed in the convexity versus the concavity. CONCLUSIONS: In bicuspid-associated aortic dilations, an asymmetric pattern of matrix protein expression was found that was consistent with the asymmetry in wall-stress distribution reported previously. Differences exist between patients with stenosis and those with regurgitation in terms of protein expression and content in the aortic wall. Further studies could clarify the relations between these findings and the pathogenesis of aortic dilatation in bicuspid aortic valve patients.

Aged↗
PubMed2005

Temporary dialysis treatments for heart failure in chronic kidney disease.

Patients with cardiac disease and chronic kidney disease are admitted to our emergency unit with signs and symptoms of severe heart failure more and more frequently. Resistance to high-dose loop diuretics imposes the use of renal replacement therapy. We treated a group of these patients with personalized bicarbonate dialysis, deciding the number and frequency of treatment sessions according to the patient's clinical conditions. Heart failure can be classified as mainly diastolic or systolic. Results show that bicarbonate dialysis is effective and well tolerated, primarily in the treatment of patients with prevalently diastolic heart failure. Patients with prevalently systolic heart failure have a worse prognosis.

Age Factors↗
PubMed2005

Creatinine clearance and hemoglobin concentration before and after heart transplantation.

Clinical studies indicate that indices of glomerular filtration rate (GFR) as serum creatinine or creatinine clearance can predict the risk of death in congestive heart failure (CHF) and in heart transplantation. The study reports data on creatinine clearance before and after heart transplantation in 160 patients followed-up for 5 years at our Unit. Pre-transplant creatinine clearance averaged 83.5+/-32 mL/min x 1.73 m(2) and was not significantly associated with 5-year mortality. Creatinine clearance significantly decreased after heart transplantation with a linear trend up to 3 years for patients with complete follow-up. Data suggest that the relation between kidney function and mortality after heart transplantation is affected by several confounders with inclusion of cause of heart disease, co-morbidity, anemia, and post-transplant decrease in kidney function.

Adult↗
PubMed2004

Native versus primary prosthetic valve endocarditis: comparison of clinical features and long-term outcome in 353 patients.

BACKGROUND AND AIM OF THE STUDY: The study aim was to compare preoperative and intraoperative features, and long-term outcome of patients operated on for native (NVE) and primary prosthetic valve endocarditis (PVE). METHODS: Between January 1978 and December 2002, 258 patients (mean age 47.5 +/- 16 years) were referred for NVE, and 95 for PVE. Demographics, clinical preoperative conditions, indications to surgery, microbiological data, surgical pathology, early postoperative course and long-term outcome were compared via hospital chart review and outpatient clinic follow up. RESULTS: Female sex prevailed in the PVE group (49.5%) versus NVE (27.1%; p < 0.0001). Mitral valve involvement was more common in PVE (46.3% versus 24.8%, p = 0.0001), and multivalvular in 16.3% of NVE patients versus 4.2% of PVE (p = 0.001). Active endocarditis (80.6% versus 58.9%, p = 0.00004) and preoperative embolism (29.5% versus 11.6%, p = 0.0002) were significantly prevalent in the NVE group. Emergency operation (21.1% versus 10.5%, p = 0.009) and preoperative NYHA class IV or V (40% versus 19.8%, p < 0.0001) were significantly more frequent in PVE. Overall hospital mortality was 11.3% (n = 40), with 6.6% among NVE patients and 24.2% among PVE (p < 0.0001). Mean follow up (94% complete) was 5.8 +/- 5.3 years (6.0 +/- 5.5 years for NVE versus 5.1 +/- 4.6 years for PVE, p = 0.191), and total follow up was 1,707.85 patient-years. Actuarial survival at 1, 5, 10 and 15 years was respectively 91, 82, 67.5 and 48.8% in NVE, and 79.7, 64.2, 33.5 and 33.5% in PVE (p = 0.0016). A significantly lower survival in PVE versus NVE was found for the mitral site subgroup (p = 0.018), but not for the aortic site (p = 0.14). Actuarial freedom from reoperation for recurrent endocarditis at 1, 5, 10 and 15 years was 97.5, 91.4, 80.5 and 49.4% in NVE versus 90.8, 84.9, 59.4 and 43.9% in PVE (p = 0.015). CONCLUSION: PVE patients were older, presented with more compromised clinical conditions, and had worse early and long-term outcomes than NVE patients. PVE had a higher incidence of recurrence and worse prognosis, especially if the mitral valve was involved.

Adult↗
PubMed2003

Improvement in accuracy of diagnosis of carotid artery stenosis with duplex ultrasound scanning with combined use of linear array 7.5 MHz and convex array 3.5 MHz probes: validation versus 489 arteriographic procedures.

OBJECTIVE: Validity of a method to improve the accuracy of carotid artery duplex scanning was tested in comparison with arteriography. STUDY DESIGN: In 489 patients who had not previously undergone arteriography, 978 carotid arteries were examined with duplex ultrasound scanning. In method A, a linear array 7.5 MHz transducer with pulsed-wave 4.7 MHz Doppler scanning was used. For the diagnosis and grading of carotid stenosis, peak systolic and end-diastolic velocity of the Doppler waves were recorded. Method B consisted of complete ultrasound imaging and color-flow mapping with a convex array 3.5 MHz transducer with pulsed-wave 2.8 MHz Doppler scanning in all patients who had previously undergone method A. Further velocity measurements were performed at the sites of stenosis. The results of methods A and B were compared with data from neurologic assessment and arteriographic studies. RESULTS: Method B showed significantly higher diagnostic agreement with arteriography than did method A (K 95% confidence interval [CI], 0.87-0.93 vs 0.79-0.85; P <.05), and the number of mistakes in grading stenosis was significantly lower (primarily because of decreased overestimation) in patients with internal carotid kinking (>60 degrees of angulation) (P <.05), distal stenosis (>20 mm from bifurcation) (P <.01), or wide acoustic shadowing (>1 cm) (P <.01) and in those without these conditions (P <.05). Compared with arteriography, diagnostic accuracy with the new method proved higher for carotid stenoses 50% or greater, 60% or greater, 70% or greater, and 80% or greater; no statistically significant difference was found for carotid stenosis 96% or greater or for carotid occlusion. Compared with data from neurologic assessment and arteriography, method B proved more accurate than method A in designating patients for carotid endarterectomy (P =.014). CONCLUSIONS: The new method significantly improved diagnostic reliability of duplex ultrasound scanning, especially in carotid arteries with kinking, distal stenosis, or wide acoustic shadowing (32.2% of all arteries studied). In clinical practice, we suggest additional use of a lower frequency transducer in cases in which these three conditions are found or suspected at first scanning.

Adult↗
PubMed2003

Asymmetric medial degeneration of the ascending aorta in aortic valve disease: a pilot study of surgical management.

BACKGROUND AND AIM OF THE STUDY: In structural aortic valve disease, medial degeneration is often associated with ascending aorta dilatation. This pathology is often asymmetric, with more severe involvement of the convex aspect of the ascending aorta. The condition can be managed with surgical excision of the diseased portion of the aortic wall and remodeling reconstruction at the time of aortic valve replacement (AVR). METHODS: Sixty-one patients underwent AVR and 'waistcoat aortoplasty'. Sinus dilatation was repaired by plicating the subcoronary redundant aortic wall using anchoring sutures of the valve prosthesis. The diseased aortic wall was removed via a triangular resection, and the aorta reconstructed with a double-layer technique, to achieve autologous reinforcement of the convex right posterolateral wall and stress reduction on the aortotomy suture line. Echocardiography was performed preoperatively, immediately postoperatively, and every six months thereafter. The significance of diameter variations was evaluated. RESULTS: There was no hospital mortality, and only low postoperative morbidity. Post-reduction diameters at the sinuses, sinotubular junction and ascending aorta were significantly less than preoperative values (p < 0.0001). During a mean follow up of 33.8 +/- 10.2 months (range: 13-50 months), no significant increase in root (p = 0.32), sinotubular (p = 0.15), or ascending diameter (p = 0.11) was observed. CONCLUSION: The 'waistcoat aortoplasty' should be considered when dealing with asymmetric ascending dilation secondary to aortic valve disease-related medial degeneration. However, additional studies with a longer follow up are needed to confirm these findings.

Adult↗
PubMed2003

Aortic valve dysfunction and dilated ascending aorta. A complex and controversial association.

Several pathogenetic mechanisms account for the association of the ascending aorta dilation with aortic valve dysfunction. Functional aortic insufficiency can derive from medial degeneration of the aortic wall and annuloaortic ectasia; leaflet structural disease can determine root dilation by increasing aortic wall stress in case of both regurgitation and stenosis; aortic valve disease and aortic aneurysm can however coexist due to two different intrinsic etiologies. In the attempt to best tailor the surgical correction of such conditions to the underlying causative mechanism, several technical options have already been developed including composite or separate aortic valve and root replacement, valve-sparing operations, and aortoplasty techniques. The criteria for surgical indication cannot leave the underlying pathogenesis out of consideration as well. The newly acquired knowledge in the basic research on this topic is expected to affect the approach to the individual patient in the future.

Aorta↗
PubMed2003

Surgical experience with "waistcoat aortoplasty": an update.

BACKGROUND: Some patients with primary aortic valve disease can present with an associated asymmetrical dilation of the aortic root and/or ascending aorta without diffuse congenital aortic wall defects. In such cases "waistcoat aortoplasty" has been performed: the present study updates the report of the results of 73 procedures. METHODS: Seventy-three patients underwent aortic valve replacement and waistcoat aortoplasty. Sinus dilation was repaired by plicating the subcoronary redundant aortic wall using the anchoring sutures of the valve prosthesis. Through a triangular resection the most diseased segment of the aortic wall was removed and the aorta was reconstructed with a double layer technique. Thus autologous reinforcement of the convex right postero-lateral wall and stress reduction on the aortotomy suture line were both achieved. Echocardiography was performed preoperatively, postoperatively and then every 6 months. The paired Student's t-test was employed to evaluate the significance of the diameter variations. RESULTS: The procedure was performed with no hospital mortality and a low postoperative morbidity. The post-reduction diameters at the sinuses, sinotubular junction and ascending aorta were significantly smaller than the preoperative ones (p < 0.001). During an echocardiographic follow-up of 39.2 +/- 12.5 months (range 14-58 months), no significant increase in the root (p = 0.18), sinotubular junction (p = 0.22), and ascending diameter (p = 0.34) was observed. CONCLUSIONS: Although further studies are needed to confirm these results in the longer term, waistcoat aortoplasty should be taken into consideration in case of asymmetric ascending dilation secondary to aortic valve disease-related medial degeneration.

Adult↗
PubMed2002

Risk of warfarin during pregnancy with mechanical valve prostheses.

OBJECTIVE: To assess the determinants of pregnancy outcome in patients with mechanical valve prostheses anticoagulated with warfarin. METHODS: Between January 1987 and January 2000, 52 patients with mechanical valve prostheses who had 71 pregnancies were anticoagulated with warfarin for the entire duration of pregnancy. Warfarin was withdrawn 48 hours before and 24 hours after a scheduled cesarean delivery carried out by the end of the 37th gestational week. The targeted international normalized ratio ranged between 2.25 and 4.0, depending on the prosthetic model. Exact univariate and multivariable analyses were performed to assess which among the following variables predicted poor pregnancy outcome: patient age, prosthetic model, site of implantation, average international normalized ratio, and average daily dose of warfarin. RESULTS: Pregnancy loss occurred in 23 of 71 of pregnancies, stillbirth in five of 71, embryopathy in four of 71 (two aborted fetuses and two full-term infants). There were no maternal deaths or thromboembolic or hemorrhagic complications. Warfarin daily dosage over 5 mg per day was a significant predictor of poor pregnancy outcome (P <.001). CONCLUSION: The risk for pregnancy complications in patients treated with sodium warfarin is higher when the mean daily dose exceeds 5 mg.

Abortion, Spontaneous↗
PubMedDate not supplied

Pierre-Joseph Desault (1738-1795)--a forerunner of modern medical teaching.

Pierre-Joseph Desault (1738-1795) was the first French professor of clinical surgery. He was chief surgeon at La Charité and Hôtel-Dieu in Paris, where he developed a new method for teaching anatomy and modified the teaching of surgery. His fame was due to his dedication and to the number and quality of fellows, who included Bichat, Louis, Corvisart, Dupuytren, Percy, Richerand, Petit, Chopart, and Gavard. He taught while performing surgery, and his school included up to six hundred fellows at a time, practicing in the 1200-bed Hôtel-Dieu. He "imprinted" his pupils with his professional teaching, his surgical procedures and his personal charm.

Anatomy↗
PubMedDate not supplied

The effect of oral protein loading on renal acidification in patients with heart failure.

BACKGROUND: The purpose of this study was to explore the renal acid-base response to acute protein load in patients with heart failure (HF). It was prompted by the fact that there are no data available regarding the role of renal tubules in maintaining acid-base balance following protein loading in HF patients. METHODS AND RESULTS: Nine male patients with HF and 12 healthy subjects (controls) were enrolled in this study. In the HF patients, average blood pH was 7.42 (0.03), average pCO2 was 36.6 mmHg (6.3) and average bicarbonate was 24.2 mmol/L (4.3). The acid-base status of patients was unaffected by meat ingestion. The values at peak glomerular filtration rate (GFR) did not differ significantly from baseline levels. An oral protein load did not influence the urinary pH, titratable acidity (TA) and ammonium excretion in the patients with HF, contrary to the findings in the controls. On the other hand, ammonium excretion in patients with HF reduced significantly compared with values from controls at baseline and following oral protein loading. Filtered and reabsorbed bicarbonate increased significantly in HF patients following meat ingestion, whereas there was no change in absolute and fractional bicarbonate excretion and fractional bicarbonate reabsorbed. CONCLUSIONS: This study demonstrated that in patients with HF, bicarbonate reabsorption increases following an oral protein load without a significant enhancement in bicarbonate excretion. The difference can be explained by the presence of respiratory alkalosis leading to bicarbonate conservation.

Absorption↗