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Biomedical subjects

G La Canna

Publications and source records attributed to G La Canna.

At least 19 recordsLinked to original sources
PubMed2002

Revascularization of hibernating myocardium: rate of metabolic and functional recovery and occurrence of oxidative stress.

BACKGROUND: Left ventricular (LV) dysfunction due to coronary artery disease (CAD) may improve after revascularization in patients with hibernating myocardium (HM). METHODS AND RESULTS: We compared the rate of metabolic (arterial-great cardiac vein differences of lactate, glucose and pyruvate) and functional (intra-operative transesophageal and epicardial echocardiography) recovery and occurrence of oxidative stress (myocardial release of oxidized glutathione (GSSG)) early after surgical revascularization, in patients with CAD, LV dysfunction and HM (n=16) vs those with preserved LV function (n=15). By comparing the two groups, we observed that, after de-clamping, in patients with HM (a) the kinetic of lactate production was converted to extraction (P<0.01 at 1, 5, 10 and 20 min after revascularization), (b) myocardial extraction of pyruvate increased (P<0.01 during the first 5 min after revascularization), (c) GSSG release was less and of shorter duration (P<0.01 at all times), (d) segmental wall motion score improved from 2.4+/-0.3 to 1.7+/-0.5 (P<0.01) as did the thickening of the akinetic territories corresponding to the antero-distal septum and to the distal anterior wall regions (to 36+/-23%, and to 36+/-13%, respectively). There was a correlation between the rate of recovery of metabolic and functional indices. CONCLUSIONS: The contractile and metabolic recovery of HM is more rapid than that of non-HM, and it is not accompanied by oxidative stress.

Blood Glucose↗
PubMed2001

Long-term results of coronary artery bypass grafting procedure in the presence of left ventricular dysfunction and hibernating myocardium.

OBJECTIVE: Long-term left ventricular (LV) performance and patient outcome after coronary artery bypass grafting (CABG) procedure in the presence of depressed LV function and hibernating myocardium (HM) have been poorly determined. Therefore, we prospectively evaluated patients undergoing CABG with severe LV dysfunction and HM to elucidate postoperative prognosis. METHODS: We enrolled 120 consecutive patients undergoing CABG with severe LV dysfunction and HM as assessed by dobutamine echocardiography and by rest-redistribution radionuclide (Thallium-201) study. Mean patient age was 60+/-9 years (range 31-77 years). Mean preoperative LVEF was 28%+/-9 (range 10-40%). All patients underwent echocardiographic study to assess LV recovery of function intraoperatively, prior to hospital discharge, at 3 months, at 1 year, and yearly during the follow-up. Univariate and multivariate analysis were performed to to evaluate predictors of postoperative survival. RESULTS: There were 2 hospital (1.6%) and 15 late (12.5%) deaths, mainly for heart failure, leading to an actuarial survival of 80+/-6% and 60+/-9% at 5 and 8 years, respectively. LVEF significantly improved perioperatively (from 28+/-9% to 40+/-2%, P<0.01). Increase in LVEF, however, was gradually offset over the time (EF of 33+/-9%, 32+/-8%, and 30+/-9% at 3 months, and 12 months, and 8 years after surgery, respectively). Furthermore, patients who experienced limited LV functional recovery perioperatively had a more remarkable decline of LVEF thereafter, and suffered from recurrence of heart failure symptoms (freedom from heart failure 82+/-5% and 60+/-8% at 4 and 8 years respectively). Advanced preoperative NYHA Class, and age were independent risks factors for reduced postoperative survival. Preoperative angina and use of arterial conduits apparently did not influence patient morbidity and mortality at long term. CONCLUSION: CABG procedure in the presence of HM enhances LV recovery of function and has a favourable prognosis. Functional benefit of the left ventricle, however, appears to be time-limited, despite remarkable improvement in patient functional capacity. Advanced preoperative heart failure, minimal perioperative improvement of LVEF, and age account for a poor long-term prognosis.

Adult↗
PubMed2001

The double-orifice technique in mitral valve repair: a simple solution for complex problems.

OBJECTIVE: The aim of this study is to report our results with the central double-orifice technique used for the treatment of complex mitral valve lesions. METHODS: The central double-orifice repair has been used in 260 patients (mean age, 56 +/- 14.3 years) over a period of 7 years. The mechanism responsible for mitral regurgitation was prolapse of both leaflets in 148 patients, prolapse of the anterior leaflet in 68, prolapse of the posterior leaflet with annular calcification or other unfavorable features in 31, and lack of leaflet coaptation for restricted motion or erosion of the free edge in 13. Degenerative disease was the cause of mitral regurgitation in 80.8% of the patients, rheumatic disease was the cause in 9.6%, endocarditis was the cause in 6.1%, and ischemic disease was the cause in 2.3%. RESULTS: Hospital mortality was 0.7%, and the overall survival at 5 years was 94.4% +/- 2.59%. Thirteen patients required a reoperation (2 early postoperatively and 11 late during the follow-up), for an overall freedom from reoperation of 90.0% +/- 3.37% at 5 years. Freedom from reoperation was lower in patients with rheumatic valve disease and in patients who did not undergo an annuloplasty procedure. CONCLUSIONS: The effectiveness and durability of the central double-orifice technique were assessed in this study. This type of repair can be a useful addition to the surgical armamentarium in mitral valve reconstruction.

Adolescent↗
PubMed2001

Gated blood pool tomography for the evaluation of global and regional left ventricular function in comparison to planar techniques and echocardiography.

BACKGROUND: Multigated radionuclide ventriculography (MUGA) is a simple and reliable tool for the assessment of global systolic and diastolic function and in several studies it is still considered a standard for the assessment of left ventricular ejection fraction. However the evaluation of regional wall motion by MUGA is critical due to two-dimensional imaging and its clinical use is progressively declining in favor of echocardiography. Tomographic MUGA (T-MUGA) is not widely adopted in clinical practice. The aim of this study was to compare T-MUGA to planar MUGA (P-MUGA) for the assessment of global ejection fraction and to transthoracic echocardiography for the evaluation of regional wall motion. METHODS: A 16-segment model was adopted for the comparison with echo regional wall motion. For each one of the 16 segments the normal range of T-MUGA ejection fraction was quantified and a normal data file was defined; the average value -2.5 SD was used as the lower threshold to identify abnormal segments. In addition, amplitude images from Fourier analysis were quantified and considered abnormal according to three different thresholds (25, 50 and 75% of the maximum). RESULTS: In a study group of 33 consecutive patients the ejection fraction values of T-MUGA highly correlated with those of P-MUGA (r = 0.93). The regional ejection fraction (according to the normal database) and the amplitude analysis (50% threshold) allowed for the correct identification of 203/226 and 167/226 asynergic segments by echocardiography, and of 269/302 and 244/302 normal segments, respectively. Therefore sensitivity, specificity and overall accuracy to detect regional wall motion abnormalities were 90, 89, 89% and 74, 81, 79% for regional ejection fraction and amplitude analysis, respectively. CONCLUSIONS: T-MUGA is a reliable tool for regional wall motion evaluation, well correlated with echocardiography, less subjective and able to provide quantitative data.

Echocardiography↗
PubMed2000

Sensitivity, specificity, and predictive accuracies of non-invasive tests, singly and in combination, for diagnosis of hibernating myocardium.

OBJECTIVE: To determine the best test(s) for predicting functional recovery of hibernating myocardium after reperfusion. METHODS: A prospective study to compare echocardiographic left ventricular diastolic wall thickness (> or =5 mm), low-dose dobutamine echocardiography and rest-redistribution thallium-201 scintigraphy, alone and in combination, for predicting recovery of left ventricular akinesis after surgical revascularization. RESULTS: Twenty-eight consecutive patients aged 58+/-9 years were studied. Of the 448 left ventricular segments, 263 were akinetic at rest; 230/263 (87%) had wall thickness > or =5 mm, 135 (51%) had a positive response and 175 (66.5%) were graded viable on thallium. Of akinetic segments 61% improved after surgery. Left ventricular score decreased from 2.3+/-0.4 to 1.8+/-0.4 (P<0.01) and ejection fraction increased from 27+/-10 to 37+/-14% (P<0.01). For predicting results at 1 year, diastolic wall thickness had a sensitivity and a predictive accuracy of a negative test of 100% but a specificity of 28% and predictive accuracy of a positive test of 61%. The addition of dobutamine echocardiography or thallium-201 improved the predictive accuracy of a positive test to 76% and 69%, respectively; the addition of both tests was not of greater benefit than that of a single test. CONCLUSIONS: Diastolic wall thickness <5 mm on echocardiography was the best simple and single predictor of non-recovery of left ventricular dysfunction. The addition of dobutamine echocardiography or thallium-201, but not both, was the best solution for predicting recovery of left ventricular dysfunction. In times of limited resources, these findings are important from a clinical point of view.

Adult↗
PubMed2000

[Evaluation of hibernating myocardium in patients with heart insufficiency].

Myocardial dysfunction due to chronic hypoperfusion (so-called hibernating myocardium) is potentially reversible if the normal coronary flow is restored. Stress echocardiography (dobutamine, post-extrasystolic potentiation) may elicit contractile reserve of the hibernating myocardium and predict accurately its functional recovery after coronary revascularization. Thus, the identification of dysfunctioning but viable myocardium may be crucial to select patients with ischemic congestive heart failure who might benefit from coronary revascularization.

Cardiotonic Agents↗
PubMed1999

Mitral valve repair for isolated prolapse of the anterior leaflet: an 11-year follow-up.

OBJECTIVE: Mitral valve insufficiency (MVI) because of involvement of the anterior mitral leaflet may pose additional risks for late outcome after mitral valve repair, because of more complex techniques. We retrospectively reviewed our experience in patients operated on for isolated anterior mitral leaflet prolapse approached by various techniques. METHODS: Between 1986 and 1997, 616 patients underwent mitral valve repair at our Institution. Isolated pathology of the anterior mitral leaflet was the cause of MVI in 84 patients (13.6%). Age ranged from 23 to 74 years (mean 50 +/- 14). Etiology of MVI was predominantly degenerative (57 patients, 67.8%), and the mechanism of the regurgitation was mainly due to a chordal rupture (58 patients, 69%). Annular dilatation was present in 75 patients (89.5%). A variety of surgical techniques were applied including chordal shortening (five patients, 5.9%), chordal transposition (three patients, 3.5%), artificial chordae (11 patients, 13%). Since 1992, however, the majority of procedures was performed using the 'edge to edge' technique (52 patients, 51.9%). Annular dilatation was treated mainly by means of a prosthetic ring (46 patients, 61.3%) whereas 18 patients (24%) underwent posterior annuloplasty using gluteraldehyde-treated native pericardium. RESULTS: Follow-up ranged from 3 to 122 months (mean 46 +/- 24 months). There were three hospital deaths (3.5%) and five late deaths (5.9%) for a Kaplan-Meier estimated survival of 87.6% at 8 years. Three patients underwent early reoperation within 30 days (3.5%), and six patients underwent late reoperation (7.1%), for a cumulative freedom from reoperation of 85.4% at 8 years. Seventy-four percent of the survivors (50 patients) are still in New York Heart Association Class I, and 92% of survivors (62 patients) have no or trivial (1+) residual mitral regurgitation at echocardiographic follow-up. CONCLUSION: In spite of the greater complexity, conservative surgery to correct anterior mitral valve prolapse pertains high success rate of long term. Recent technical modifications ('edge-to-edge' technique) may allow more expeditious and reproducible procedures with expected favorable influence of mitral valve repair applicability.

Cardiac Surgical Procedures↗
PubMed1998

Different outcomes of the reperfused myocardium: insights into the comments of stunning and hibernation.

There are several potential outcomes of myocardial ischaemia. When ischaemia is severe and prolonged, irreversible damage occurs and there is no recovery of contractile function. Interventions aimed at reducing mechanical activity and oxygen demand either before ischaemia or during reperfusion have been shown to delay the onset of ischaemic damage and to improve recovery during reperfusion. When myocardial ischaemia is less severe but still prolonged, myocytes may remain viable but exhibit depressed contractile function. Under these conditions, reperfusion restores complete contractile performance. This type of ischaemia leading to a reversible, chronic left ventricular dysfunction has been termed 'hibernating myocardium'. It is important clinically recognize hibernation as reperfusion of hibernating myocardium by angioplasty or heart surgery restores contraction and this correlates with long term survival. A third possible outcome after a short period of myocardial ischaemia is a transient post-ischaemic ventricular dysfunction, a situation termed 'stunned myocardium'.

Chronic Disease↗
PubMed1998

The edge-to-edge technique: a simplified method to correct mitral insufficiency.

OBJECTIVE: Repair of mitral regurgitation (MR) is more demanding in case of prolapse of the anterior leaflet, posterior leaflet with calcified annulus, or prolapse of both leaflets. We evaluated a repair which consists of anchoring the free edge of the prolapsing leaflet to the corresponding free edge of the facing leaflet: the 'edge-to-edge' (E-to-E) technique. The correction results in a double orifice valve when the prolapse is in the middle portion of the leaflet and in a smaller valve orifice when the prolapse is close to a commissure. METHODS: Out of 432 patients with MR submitted to valve repair between January 1991 and September 1997, 121 (mean age 56 +/- 15.8 years) underwent E-to-E correction. The most prevalent etiology was degenerative disease (82 patients, 68%). The mechanism of MR was anterior leaflet prolapse (61 patients), posterior leaflet prolapse (24 patients), prolapse of both leaflets (28 patients) and other complex mechanisms (8 patients). In 72 patients, a double orifice was created, the paracommissural repair was done in 49 patients. RESULTS: Hospital mortality was 1.6%. Overall survival was 92 +/- 3.1% at 6 years with 95 +/- 4.8% freedom from reoperation. Mortality was unrelated to the type of repair. Mitral stenosis was never observed after the correction. At the follow-up (mean 2.2 +/- 1.5 years), all patients but 15 are class I or II. Symptoms at the follow-up are not related to residual MR. CONCLUSIONS: Midterm results of this alternative repair technique are promising, considering the high prevalence of complex anatomical lesions. The technique is simple, easily reproducible and rapidly feasible also when mitral exposure is suboptimal.

Adolescent↗
PubMed1998

"Double-orifice" technique to repair extensive mitral valve excision following acute endocarditis.

The use of conservative surgical techniques to treat mitral valve regurgitation secondary to acute endocarditis is controversial. Reconstruction of the anterior leaflet may represent an additional challenge in such a setting. We report a case of mitral valve repair where extensive excision of the anterior leaflet and related chordae tendinea was necessary because of large vegetation secondary to acute endocarditis. The "double-orifice" technique was performed and allowed the salvage of the native valve. There was no recurrent infection at 6 months from surgery, with optimal hemodynamic results.

Acute Disease↗
PubMed1998

Evaluation of mean right atrial pressure by two-dimensional and Doppler echocardiography in patients with cardiac disease.

BACKGROUND: Several approaches have been used for noninvasive estimation of right atrial pressure (RAP), but, no currently available method has gained any definite validation. The purpose of this study was to evaluate the accuracy of two-dimensional and Doppler echocardiography in estimating mean RAP in patients with cardiac disease. METHODS: We examined the relation of mean RAP to right atrial size and function, size and respiratory changes of inferior vena cava and Doppler parameters of tricuspid and hepatic vein flow in 114 consecutive patients (77 men, 37 women; mean age 57 +/- 12 years) with various cardiac diseases undergoing cardiac catheterization. Echocardiographic studies were performed within 24 hours before catheterization (mean interval 6 +/- 3 hours). Patients were assigned to 3 groups according to the values of mean RAP (group 1, < or = 8 mmHg; group 2, between 9 and 12 mmHg; group 3, > 12 mmHg). RESULTS: Mean RAP ranged from 3 to 20 mmHg (mean 9.1 +/- 4.3 mmHg). It correlated most strongly with the collapsibility index of inferior vena cava (IVCCI) (r = -0.76), minimal inspiratory diameter of inferior vena cava (r = 0.72) and deceleration time of early tricuspid flow (DT) (r = -0.61). Discriminant analysis demonstrated that IVCCI and DT were major determinants of mean RAP with 81.6% of cases correctly assigned to study groups: 96% of patients of group 1 and 87% of patients of group 3 were identified, whereas the accuracy in identifying the patients of group 2 was lower (46%). An IVCCI > 45% was the best cutoff point in predicting a mean RAP < or = 8 mmHg; an IVCCI < 35% and a DT < 150 msec were the best cutoff points in predicting a mean RAP > or = 15 mmHg. The best multivariate equation predicting mean RAP was: mean RAP = 23.3 - 0.2 IVCCI -0.026 DT (r = 0.80, R2 = 0.64). This equation was 81% sensitive and 84% specific in detecting a mean RAP < or = 8 mmHg and 74% sensitive and 97% specific in detecting a mean RAP > 12 mmHg. CONCLUSIONS: Mean RAP can be estimated noninvasively by two-dimensional and Doppler echocardiography. The combined analysis of IVCCI and DT provides an accurate prediction on mean RAP < or = 8 mmHg and > 12 mmHg, whereas the prediction of intermediate values is less accurate.

Adult↗
PubMed1997

[Repair in rheumatic mitral valve insufficiency].

OBJECTIVES: Emerging evidence indicates that etiology plays an essential role in the results of mitral valve repair. In this study, we examined the long-term performance of this procedure in 61 consecutive patients with pure rheumatic mitral insufficiency. PATIENTS: Patient ages ranged from 4 to 74 years (mean: 51.7 +/- 16). Preoperatively, 94% of the patients were in NYHA class II or III. RESULTS: There was no hospital mortality. According to actuarial methods 94.1% of the patients were alive 7 years postoperatively and 83.3% were reoperation free. Freedom from reoperation was significantly higher in patients who received a prosthetic ring than in those who had other types of annuloplasty (96.7% vs 59.3%; p = 0.001). As opposed to the literature, in our series there was no relationship between valve failure and age at the time of reoperation. There were only two cases of thromboembolism and one of infective endocarditis. CONCLUSIONS: This study confirms that mitral valve reconstruction in rheumatic valve insufficiency can yield satisfactory long-term clinical results, although they are less than optimum compared with those obtained in patients with degenerative disease. Favourable results depend on routine use of a prosthetic ring as well as adequate patient selection. Attention should be focused on improved detection and suppression of rheumatic activity at the time of operation.

Actuarial Analysis↗
PubMed1996

Valve repair for traumatic tricuspid regurgitation.

OBJECTIVE: The review of six cases of valve repair for traumatic tricuspid regurgitation in our institution and 74 in the literature in order to assess effective methods of treating this lesion. METHODS: Tricuspid valve regurgitation is a rare complication of blunt chest trauma. Optimal treatment for this condition is still controversial ranging from long-term medical therapy to early surgical correction. We followed the cases of six consecutive patients with post-traumatic tricuspid incompetence who were successfully treated with reparative techniques. All patients were male and their ages ranged from 18 years to 42 years. Valve regurgitation was always secondary to blunt chest trauma due to motor vehicle accident. The mechanism of valve insufficiency was invariably anterior leaflet prolapse due to chordal or papillary muscle rupture associated with annular dilatation. Surgical procedures included Carpentier ring implant (5 patients), Bex posterior annuloplasty (1 patient), implant of artificial chordae (4 patients), papillary muscle reinsertion (2 patients), commissuroplasty (1 patient) and "artificial double orifice" technique (1 patient). RESULTS: Tricuspid insufficiency improved in all patients after the correction. No complications were recorded and all patients were asymptomatic at the follow-up. CONCLUSIONS: Since post-traumatic tricuspid regurgitation is effectively correctable with reparative techniques, early operation is recommended to relieve symptoms and to prevent right ventricular dysfunction.

Adolescent↗
PubMed1996

Left ventricular dysfunction due to the new ischemic outcomes: stunning and hibernation.

Several potential manifestations and outcomes are associated with myocardial ischemia and reperfusion. When ischemia is severe and prolonged, irreversible damage occurs and there is no recovery of contractile function. When ischemia is less severe or shorter in duration, recovery of contraction may occur instantaneously or more commonly, after considerable delay, which is the condition recognized as "stunned myocardium." Stunning is defined as a transient left ventricular dysfunction that persists after reperfusion despite the absence of irreversible damage and restoration of normal or near-normal coronary flow. Oxidative stress and alteration of calcium homeostasis during reperfusion are the probable causes of stunning. Clinically, stunning may occur after acute infarction, successful thrombolysis, unstable angina, angioplasty, resolution of coronary spasm, open-heart surgery, or transplantation. It can be treated with interventions aimed at prevention or reversal. When ischemia is prolonged but less severe, myocytes may remain viable but exhibit depressed contraction. Under these conditions, reperfusion restores normal contractile performance. This type of ischemia, leading to a reversible, chronic left ventricular dysfunction, has been termed "hibernating myocardium." The intrinsic mechanisms of this condition are unknown. Clinically, it is very important to diagnose hibernation because reperfusion of the hibernating myocardium by angioplasty or heart surgery restores contraction, and this correlates with long-term survival. A number of methods are available to access the hibernating myocardium. These include cardiac imaging techniques that evaluate myocardial viability, such as positron emission tomography and thallium myocardial imaging, or methods that evaluate contractile reserve, such as low-dose dobutamine echocardiography. Interestingly, reperfusion of patients with end-stage ischemic cardiomyopathy and hibernating myocardium can be considered an alternative to transplantation.

Cardiomyopathies↗
PubMed1995

Surgical management of left ventricular free wall rupture after acute myocardial infarction.

Left ventricular rupture after acute myocardial infarction occurs more often than suspected and diagnosis is rarely made before death. Left ventricular rupture has been reported to contribute to the overall in-hospital mortality after acute myocardial infarction in up to 24% of cases and to be present in 40% of patients dying within the first week after infarction. Only prompt diagnosis and aggressive surgical treatment can be lifesaving under these circumstances. Between February 1991 and August 1993 five patients underwent emergency operation for left ventricular rupture after acute myocardial infarction using exclusively transoesophageal echocardiography as a diagnostic tool. All patients had evidence of cardiac tamponade and electrocardiography showed signs of anterolateral acute myocardial infarction in one, inferolateral acute myocardial infarction in three and lateral acute myocardial infarction in one. In two cases the infarcted area was debrided and an interrupted pledgetted 2/0 polypropylene suture was placed from inside of the ventricle outward to the epicardial surface and then through the pericardial patch. In the other three cases an original technique was used: an autologous glutaraldehyde-stiffened pericardial patch was sealed over the infarcted area using fibrin glue and fixed with running suture on the surrounding healthy myocardium. One patient died in the operating room because of low cardiac output syndrome which was possibly the result of an excessively extended area of infarction. Left ventricular rupture is a catastrophic complication of acute myocardial infarction and prompt diagnosis with transoesophageal echocardiography followed by emergency operation can be lifesaving.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Reparative surgery of the mitral valve in bacterial endocarditis].

INTRODUCTION: Short and long-term results of valve repair for pure mitral insufficiency resulting from native valve endocarditis are reported in 28 consecutive patients with a mean age of 55 years (range 18-74). METHODS: Six patients had acute endocarditis, with positive blood cultures in three of them. The mean time between onset of endocarditis symptoms and operation was 23 days in patients with acute endocarditis and 4.6 years in patients with healed endocarditis. Preoperatively, 87% of the patients were in NYHA class III. Indications for operation were heart failure (24 patients) and uncontrolled sepsis (4 patients). Mitral valvuloplasty was combined with other procedures in 4 patients. There was previous underlying valve pathology in 75%. RESULTS: Mitral repair was performed according to the techniques proposed by Carpentier; in 2 cases we used an original technique consisting of a double-orifice repair. Only one patient died in the hospital (operative mortality: 3.5%). By actuarial methods 96% of the patients were alive 6 years postoperatively. During the follow-up period there was no recurrence of endocarditis and no reoperation for valvular insufficiency. Ninety-three per cent of the patients were in NYHA class I or II. CONCLUSIONS: We conclude that mitral valve repair for insufficiency resulting from bacterial endocarditis is possible in acute and healed disease, has a low operative mortality and has resulted in patients free of recurrent infection. Mitral valve repair is an attractive alternate to valve replacement in bacterial endocarditis.

Acute Disease↗