Echocardiographic evaluation and clinical management of ductal shunting in hemodynamically unstable preterm neonates without congenital heart disease in the pediatric intensive care unit.

Although significant steps have been taken to monitor complex hemodynamics in neonatal and pediatric intensive care units, cardiovascular function in neonates is still evaluated by measuring blood pressure, heart rate, diuresis, central venous pressure (if a central venous catheter was placed), capillary refill time and oxygen saturation measurement in the upper and lower extremities. The use of other non-invasive or invasive technologies (for example, continuous impedance cardiography, transesophageal Doppler and continuous pulse contour methods) is, in fact, quite problematic in neonates in whom relevant hemodynamic changes are common during the transition to postnatal life. For these reasons, use of transthoracic echocardiography, performed by skilled pediatric intensivists, is increasing in several dedicated centers to guide treatment choices in hemodynamically unstable neonates.

Opening and closing characteristics of the aortic valve after valve-sparing procedures using a new aortic root conduit.

BACKGROUND: The durability of aortic valve-sparing procedures is negatively affected by increased leaflet stress in the absence of normally shaped sinuses of Valsalva. We compared valve motion after remodeling procedures using a standard conduit and a specifically designed aortic root conduit. METHODS: Echocardiographic studies of the aortic valve dynamics were performed in 14 patients after remodeling of the aortic root (7 standard conduits, group A; 7 new conduits, group B) and in 7 controls (group C). Opening and closing leaflet velocities and percent of slow closing leaflet displacement were measured. Root distensibility and the pressure strain of the elastic modulus were measured at all root levels. RESULTS: Root distensibility and the pressure strain of the elastic modulus were different in group A and B only at the sinuses (p < 0.001). Opening and closing leaflet velocities were not different among groups. Slow closing leaflet displacement was markedly more evident in group B patients (24.2%+/-1.9% versus 2.5%+/-1.9% in group A, p < 0.001) and similar to controls (22.1%+/-7.9%). CONCLUSIONS: The new conduit guarantees dynamic features of the aortic valve leaflets superior to those obtained with standard conduits and more similar to normal subjects.

Mid-term follow-up of aortic root remodelling compared to Bentall operation.

OBJECTIVES: Aortic valve sparing with root remodelling has proven useful in cases of aortic regurgitation secondary to ascending aorta disease. An excessive rate of re-operation for recurrent aortic regurgitation after this conservative approach might compensate the prosthesis-related risk of the Bentall operation. METHODS: From January 1995 to September 2000, 69 consecutive patients with aortic expansive aneurysm and concomitant aortic valve disease, were submitted to the Bentall operation (group A, n=37) in the presence of an abnormal valve, or to root remodelling (group B, n=32) in cases of secondary aortic incompetence. One patient in group A and four in group B had Marfan syndrome. The follow-up was 1021 patient-months (range, 1-68 months) in group A and 926 in group B (1-64 months). The event-free survival was calculated using the Kaplan-Meier method, and the difference between curves was evaluated using the Mantel-Cox log-rank test. RESULTS: The operative mortality was 5% in group A and 0% in group B. One patient died at follow-up in group A and none in group B. Four patients (three Marfan) in group B were re-operated on because of recurrent aortic regurgitation. The 5-year event-free survival was 88+/-7% in group A and 82+/-8% in group B (P=0.58). Early residual aortic regurgitation remained stable over time only in patients with good early results. CONCLUSIONS: Mid-term follow-up failed to reveal statistically significant differences in the clinical outcome between remodelling and the Bentall operation. Our results support the widespread use of root remodelling, provided that an indication to this conservative approach is achieved after careful, case-by-case evaluation. A good early operative result is likely to remain stable over time.

Bentall procedure with a stentless valve and a new aortic root prosthesis.

We describe a technique to replace the aortic root by means of a stentless valve and a new aortic root Dacron graft (Gelweave Valsalva, Sulzer Vascutek, Renfrewshire, Scotland) that allows an anatomical reconstruction of the sinuses of Valsalva.

[Atrial septal aneurysm with cerebral ischemia: potential pathogenetic role of associated cerebral vascular malformation]. / Aneurisma del setto interatriale ed eventi ischemici cerebrali: il possibile ruolo patogenetico di una malformazione vascolare cerebrale associata.

Atrial septal aneurysm can be associated with other cardiovascular diseases such as atrial septal defect, patent ductus arteriosus, pulmonary hypertension and cerebrovascular events (transient ischemic attack or stroke). The introduction of transthoracic and more recently transesophageal echocardiography allowed for a more frequent observation of this pathology and also suggested that atrial septal aneurysm is a risk factor for cerebral ischemia. However, the pathophysiological pathway is still unclear. In January 1997 a 33-year-old man was admitted to our hospital because of atrial septal aneurysm and a previous cerebrovascular event. Magnetic resonance imaging revealed a cerebrovascular malformation and transesophageal echocardiography confirmed the presence of atrial septal aneurysm. We hypothesize that a common etiopathogenetic pathway may cause both the cardiac and cerebrovascular anomaly and that the latter may be responsible alone for cerebral ischemic events; thus in the presence of an atrial septal aneurysm associated with a cerebrovascular malformation, a conservative medical approach may be the treatment of choice.

A new aortic Dacron conduit for surgical treatment of aortic root pathology.

BACKGROUND: This article describes a new aortic Dacron conduit that has been designed for use in all types of surgery of the aortic root. Its use is aimed at facilitating the surgical procedure and obtaining a natural anatomical configuration of the aortic root. METHODS: The modified Dacron conduit is obtained by adding a smaller piece of Dacron tube that is resilient in the horizontal plane to one end of a standard Dacron conduit. Upon implantation, this small piece of Dacron conduit will stretch in the horizontal plane creating pseudosinuses and a new sinotubular junction. This modified conduit has been used in 4 cases for a Bentall operation in association with a mechanical or a biological valve, in 4 cases in a Yacoub type of valve sparing procedure and in 1 case in a David type I of valve sparing procedure. All patients had aortic root aneurysm with severe aortic regurgitation. There were 6 males and 3 females with a mean age of 61 +/- 16 years. In most cases a 28 mm Dacron conduit was used. RESULTS: All surgery was carried out without mortality or morbidity. The creation of pseudosinuses was confirmed intraoperatively by visual inspection. Transesophageal echocardiography in patients who had undergone the Bentall operation showed a normally functioning valve prosthesis with a suitably shaped aortic root. In patients who had undergone the valve sparing procedures it showed a competent aortic valve, the creation of pseudosinuses of normal shape and depth, and the presence of a well defined sinotubular junction. Angiography confirmed that the prosthetic aortic root perfectly resembled the normal root anatomy. CONCLUSIONS: This modified new aortic root conduit appears to perfectly reproduce a normal root anatomy without the need of modifying the original techniques.

Regional distribution and timing of wall motion abnormalities during echo-dipyridamole stress test in patients with stable angina: the elusive link between coronary stenoses and myocardial ischemia.

BACKGROUND: Classic experimental studies have shown that in the presence of a flow-limiting coronary artery stenosis, myocardial ischemia during metabolic or pharmacological arteriolar vasodilation causes wall motion abnormalities, which precede electrocardiographic (ECG) changes in the myocardial regions supplied by the stenotic branch. The aim of this study was to establish whether in patients with chronic stable angina the regional distribution of wall motion changes and sequence of ischemic events are similar to that observed in experimental models, as currently believed. METHODS: The study population consisted of 20 men and 4 women (mean age 59 +/- 10 years) who were recruited on the basis of the following criteria: 1) a history of chronic stable angina without clinical and instrumental evidence of previous myocardial infarction; 2) reproducible positive exercise tests for ECG myocardial ischemia and anginal pain; 3) angiographically normal left ventricular function; 4) isolated stenosis of the left anterior descending coronary artery (LAD). Patients underwent continuous 12-lead ECG and echocardiographic monitoring during dipyridamole infusion. RESULTS: During dipyridamole infusion 3 patients (13%) did not develop echocardiographic changes, ECG changes or angina, 14 (58%) exhibited ECG changes, 18 (75%) lamented angina and 16 (67%) developed echocardiographic changes. In 5 of these 16 patients (31.5%) echocardiographic changes occurred in LAD-dependent territories only, in 5 they occurred in non-LAD-dependent territories only (31.5%) and in 6 (37%) they occurred in both LAD- and non-LAD-dependent territories. A total of 14 patients exhibited both echocardiographic and ECG changes and/or angina. In 6 of these 14 patients (43%) echocardiographic changes were the first ischemic events; in the remaining 8 patients (57%) ECG changes and/or angina were the first ischemic events. CONCLUSION: In the majority of patients during dipyridamole infusion regional wall motion changes occur in territories supplied by non-stenotic coronary artery branches; they are probably caused, therefore, by distal vessel dysfunction. Furthermore, the sequence of ischemic events is different in individual patients. These findings indicate that in stable angina the mechanisms of ischemia are multiple and that the link between coronary stenoses and myocardial ischemia is very elusive.

[Bentall-DeBono intervention: 8 years of clinical experience]. / Intervento di Bentall-DeBono: otto anni di esperienza clinica.

BACKGROUND: Annulo-aortic ectasia is a dilation of the aortic root with the involvement of the Valsalva sinuses. In 1968 Bentall and DeBono proposed to replace the aortic valve, the Valsalva sinuses and the ascending aorta with a composite tube graft containing aortic valve prosthesis. Consequently coronary ostia had to be reimplanted on the prosthetic tube. Recently the use of new materials has resulted in a more acceptable operative risk, and postoperative bleeding and late mortality have been reduced. METHODS: From January 1991 to December 1998, 44 out of 241 patients were operated on with the Bentall-DeBono procedure, affected by dissecting or expansive aneurysm of the ascending aorta. Of the 44 patients (35 males, 9 females, mean age 53.7 years), 3 presented with acute aortic dissection, 5 were asymptomatic, 10 were in NYHA functional class II, 14 in class III, 9 in class IV, and 2 in CCS class 4; 1 patient had dysphonia; 37 patients presented with isolated aortic regurgitation, and 7 associated aortic valvular stenosis. The diagnosis of acute dissection was made by transesophageal echocardiography and that of expansive aneurysm by thorax helical computed tomographic scanning and/or magnetic resonance imaging and cardiac catheterization. Follow-up was obtained in 100% of the patients for an average of 23 +/- 20.9 months (range 4-79 months). RESULTS: Four patients (9%) died; in 4 patients (9%) postoperative bleeding needed reoperation, in 5 (11.4%) a permanent pacemaker for atrioventricular block was implanted, and 1 patient (2.3%) had transient hemiparesis. At univariate analysis predictive factors for operative risk were NYHA functional class IV (p < 0.005) and atherosclerotic etiology (p < 0.05). At follow-up 7 late deaths occurred for an actuarial survival at 24 months of 75 +/- 9%. Causes were sudden death in 3 patients, cardiac failure in 3 and stroke in 1 patient; 31 surviving patients (94%) were in NYHA functional class I and 2 patients in class II (6%). CONCLUSIONS: The Bentall-DeBono procedure involves moderate risk with good results; clinical presentation and associated valvular pathology influence early and mid-term results.

Residual aortic valve regurgitation after aortic root remodeling without a direct annuloplasty.

BACKGROUND: Aortic insufficiency secondary to degenerative aneurysms of the ascending aorta can be surgically treated with replacement of the valve or with remodeling of the aortic root. METHODS: In 15 patients who underwent aortic root remodeling from January 1994 to December 1996, we evaluated the postoperative aortic regurgitation and correlated it with several anatomic and functional variables. Operative success was defined as a residual aortic regurgitation less than or equal to 1 on a scale of 0 to 4. RESULTS: Root dimensions and aortic incompetence decreased significantly after the operation (p < 0.0001). The difference between preoperative and postoperative root diameters (p = 0.0006) and the presence of Marfan's syndrome (p < 0.0001) were independently predictive of persisting significant aortic insufficiency. Operative success was obtained in patients with a difference between preoperative and postoperative root diameters smaller than 30 mm. CONCLUSIONS: Aortic root remodeling is effective in reducing aortic regurgitation. Severe aortic root dilatation may result in excessive geometric alteration, leading to suboptimal results. The choice of a larger graft contributes to avoiding excessive geometric constraint of a profoundly diseased aortic root. Indication to undergo root remodeling should be evaluated cautiously in patients with Marfan's syndrome.

Regression of left ventricular hypertrophy after aortic valve replacement for aortic stenosis with different valve substitutes.

OBJECTIVE: Stentless biologic aortic valves are less obstructive than stented biologic or mechanical valves. Their superior hemodynamic performances are expected to reflect in better regression of left ventricular hypertrophy. We compared the regression of left ventricular hypertrophy in 3 groups of patients undergoing aortic valve replacement for severe aortic stenosis. Group I (10 patients) received stentless biologic aortic valves, group II (10 patients) received stented biologic aortic valves, and group III (10 patients) received bileaflet mechanical aortic valves. METHODS: Echocardiographic evaluations were performed before the operation and after 1 year, and the results were compared with those of a control group. Left ventricular diameters and function, left ventricular wall thickness, and left ventricular mass were assessed by echocardiography. RESULTS: Group I patients had a significantly lower maximum and mean transprosthetic gradient than the other valve groups (P = .001). One year after operation there was a significant reduction in left ventricular mass for all patient groups (P < .01), but mass did not reach normal values (P = .05). Although the rate of regression in the interventricular septum and posterior wall thickness differed slightly among groups, their values at follow-up were comparable and still higher than control values (P = .002). The ratio between interventricular septum and posterior wall and the ratio between wall thickness and chamber radius did not change significantly at follow-up. CONCLUSIONS: Because the number of patients was relatively small, we could not use left ventricular mass regression after I year to distinguish among patients undergoing aortic valve replacement for aortic stenosis by means of valve prostheses with different hemodynamic performances.

Extent and pattern of regression of left ventricular hypertrophy in patients with small size CarboMedics aortic valves.

OBJECTIVE: To assess the extent and pattern of regression of left ventricular hypertrophy after valve replacement for aortic stenosis, we studied 26 patients receiving either 19 or 21 mm CarboMedics valves (group I, 13 patients) or either 23 or 25 mm CarboMedics valves (group II, 13 patients). The studies were done before the operation and after 3 years, and results were compared with those of 10 control patients. METHODS: Left ventricular end-diastolic and end-systolic diameters and volumes, ejection fraction and fractional shortening, and interventricular septum and posterior wall thickness were measured. The ratio between interventricular septum and posterior wall thickness, the ratio between left ventricular wall thickness and left ventricular chamber radius, and the left ventricular mass were then calculated. RESULTS: At follow-up there was a significant reduction in the left ventricular mass, interventricular septum, and posterior wall thickness for both patient groups (p < 0.01). However, only the posterior wall thickness reached normal values; the interventricular septum and the left ventricular mass indices were still significantly greater than in the control group (p < 0.01). Because of the incomplete regression of interventricular septal hypertrophy, the ratio between interventricular septum and posterior wall thickness was similar between both patient groups but it was significantly higher than in control subjects (p < 0.01). The ratio between wall thickness and chamber radius did not decrease significantly in group II patients, in whom it remained above the control values. CONCLUSION: Having a bileaflet aortic prosthesis of one size larger did not seem to significantly influence the pattern and the extent of regression of left ventricular hypertrophy after an intermediate period of follow-up.

Hemodynamic performances of small diameter carbomedics and St. Jude valves.

BACKGROUND AND AIMS OF THE STUDY: Optimal hemodynamic performances are of paramount importance when implanting a mechanical valve in patients with a small aortic annulus. A Doppler echocardiographic study was performed to compare the hemodynamic performances of small CarboMedics and St. Jude valves. MATERIALS AND METHODS: Twenty-nine patients receiving either a 19 mm (n = 10) or a 21 mm (n = 10) CarboMedics valve or a 19 mm (n = 9) St. Jude Med HP valve were evaluated. A Doppler echocardiographic study was performed at rest and two minutes after treadmill exercise with the Bruce protocol. Peak and mean gradients across the valve were estimated; effective orifice area, performance index and discharge coefficient were calculated. Heart rate, blood pressure and cardiac output were all significantly increased with exercise. RESULTS: Peak and mean gradients at rest were significantly higher (p < 0.05) in the 19 mm CarboMedics valve (40.2 +/- 15 mmHg and 22.6 +/- 9 mmHg, respectively) when compared either with 21 mm CarboMedics valve (27.6 +/- 6.8 mmHg and 14.2 +/- 3.4 mmHg, respectively) or with the 19 mm St. Jude HP valve (23.6 +/- 10.4 mmHg and 13.6 +/- 5 mmHg, respectively). Peak and mean gradients were not modified with exercise for the 19 mm CarboMedics valve and significantly increased for the 21 mm CarboMedics and the 19 mm St. Jude HP valves. Although these values were still higher in the 19 mm CarboMedics valve, they did not reach the level of statistical significance when compared with the other two valve groups. CONCLUSIONS: The 19 mm St. Jude HP valve shows hemodynamic performances at rest that are similar to those of the 21 mm CarboMedics valve and superior to those of the 19 mm CarboMedics valve. With exercise both sizes of the CarboMedics valve show an in vivo discharge coefficient close to one, testifying to a full utilization of the internal orifice area.

[Early indicators of diabetic nephropathy. Changes in selective proteinuria]. / Indicatori precoci della nefropatia diabetica. Alterazioni della proteinuria selettiva.

Increased morbidity and mortality occur in diabetics with kidney disease. The decrease in fixed anionic charges is considered an early abnormality occurring well before any clinical sign of disease. It has been attached importance to the study of protein charge-selectivity decreased in diabetes in order to find the parameters which highlight the initial preclinical stage of diabetic nephropathy. To investigate the role of protein charge in early diabetic proteinuria, the clearance of protein differing in charge and/or size (anionic and cationic IgG, albumin) was evaluated in type 1 diabetic patients: 18% of them showed increased values of albuminuria. Anionic and total IgG clearances significantly increased in 30% and 12% of the patients and were correlated with the duration of the disease. The anionic/cationic IgG clearance ratio tended to increase in parallel with albumin clearance, but once above macroalbumonuric levels, it tended to fall again, indicating the concomitant presence of size-selectivity loss. In addition to albumin excretion, the anionic IgG clearance and the anionic/cationic IgG ratio, may be valuable in assessing early kidney protein charge-selectivity impairment and in better characterizing normoalbuminuric patients and those in the preclinical stage of diabetic nephropathy.