Biomedical subjects

G Melina

Publications and source records attributed to G Melina.

14 recordsLinked to original sources

PubMed2001

Emergency operation for acute type A aortic dissection: neurologic complications and early mortality.

BACKGROUND: Acute type A aortic dissection is a surgical emergency still associated with high postoperative complications. The aim of this study was to investigate factors for hospital mortality and neurologic deficit in patients undergoing emergency operation for acute type A aortic dissection. METHODS: Eighty-five consecutive patients (age range, 20 to 82 years) operated on for acute type A aortic dissection over a 6-year period were evaluated. Univariate and stepwise multiple logistic regression analyses were conducted among 32 perioperative variables. RESULTS: All patients underwent surgical procedures under deep hypothermic circulatory arrest. Antegrade or retrograde cerebral perfusion was used in 23 patients (27.1%) and 18 patients (21.2%), respectively. Forty-three patients underwent arch/hemiarch replacement and the ascending aorta was replaced in 42 patients. Overall mortality rate was 25.9% (22 of 85 patients). Multiple logistic regression analysis showed that lack of cerebral perfusion (p = 0.021) and postoperative renal failure (p = 0.006) were the best predictors for hospital death. Twenty-one patients (24.7%) experienced neurologic accidents. The risk factor for postoperative neurologic complication was lack of cerebral perfusion (p = 0.013). Hospital mortality was 13% (3 of 23 patients) and 16.7% (3 of 18 patients) in the antegrade and retrograde cerebral perfusion groups (p > 0.05) and neurologic deficit was 13% (3 of 23 patients) and 11.1% (2 of 18 patients), respectively (p > 0.05). CONCLUSIONS: Hospital mortality and neurologic complications in patients undergoing emergent operation for acute type A aortic dissection were reduced when cerebral perfusion was used with deep hypothermic circulatory arrest.

Adult↗

PubMed2001

Electron beam tomography for cusp calcification in homograft versus Freestyle xenografts.

BACKGROUND: We have previously shown, by means of electron beam tomography, the pattern of calcification of the aortic root wall of homografts and porcine xenografts after aortic root replacement. However, application of similar methods for cusp calcification raises specific problems that have not been addressed before. METHODS: A new method for localizing and quantifying calcification of the aortic valve cusps has been evolved. Intravenous contrast-enhanced electron beam tomography was introduced to visualize the aortic cusps. This technique was applied to quantify cusp calcification in 37 patients after aortic root replacement with a homograft (group H) or a Medtronic Freestyle valve (group F) at set intervals between 6 months and 2 years. A calcification score in Hounsfield units (HU) and a calcified volume score in cubic millimeters were calculated. RESULTS: The aortic leaflets were clearly visualized in all patients. The mean calcium score in the cusps was 28.8+/-64.4 HU in group F and 62.4+/-66.9 HU in group H (p = not significant). The mean calcified volume score was 327.0+/-425.9 mm3 in group F and 642.0+/-443.0 mm3 in group H (p = not significant). CONCLUSIONS: Contrast enhancement electron beam tomography is a useful tool for quantification of calcium in the aortic valve leaflets. Our preliminary results show a tendency toward more calcification in the homografts. This needs to be studied further in a bigger cohort of patients followed up for longer periods.

Adult↗

PubMed2001

A novel technique for giant left atrium reduction.

We herein describe a safe and reproducible technique for left atrial volume reduction in patients with a giant left atrium. In a 56-year-old patient undergoing redo mitral valve replacement, the left atrium measured 18 x 20 x 17 cm occupying the middle-lower segment of the right hemithorax with compression of the adjacent organs. The left atrial volume was reduced by triangular resections of the atrial wall and the mitral valve was replaced using a mechanical prosthesis. The postoperative course was uneventful and the left atrial diameter was 11.2 cm at the latest control.

Cardiac Surgical Procedures↗

PubMed2000

A quantitative study of calcium deposition in the aortic wall following Medtronic Freestyle compared with homograft aortic root replacement. A prospective randomized trial.

BACKGROUND AND AIM OF THE STUDY: Unstented aortic valve substitutes offer many of the theoretical advantages of homografts such as superior hemodynamic performance and enhanced durability, particularly when inserted as a root. Many of these depend on the maintained flexibility of the valve components. Calcification of the aortic wall may adversely affect these phenomena. Electron beam computed tomography has been used to evaluate aortic wall calcification in patients undergoing aortic root replacement in a prospective randomized trial designed to compare the Medtronic Freestyle valve with the homograft valve replacement. METHODS: Patients were followed with electron beam computed tomography scans of the aortic root at six-monthly intervals after surgery. A calcification score (Hounsfield units) and a calcified volume score (mm3) were obtained from each scan using a new modified technique. Results were related to hemodynamic data from echocardiography. The prevalence of calcification was also related to the homograft donor age. RESULTS: Seventy-six patients (age range: 40-79 years) were randomized to root replacement with either homograft (n = 31) or Freestyle (n = 45) valves. Fifty-three scans of the aortic root were performed postoperatively in 37 patients. No statistical difference between the two groups was found at six and 12 months after surgery. However, after 18 months the calcified volume score was 5903.8+/-2356.8 mm3 in the homograft versus 2725.6+/-1500.5 mm3 in the Freestyle group (p = 0.017). There was a correlation between calcification score, calcified volume score and left ventricular mass (r = 0.323, p = 0.093 and r = 0.350, p = 0.068, respectively) on the one hand, and calcification score, calcified volume score and valve size on the other hand (r = 0.178, p = 0.466 and r = 0.068, p = 0.780, respectively). CONCLUSIONS: Electron beam computed tomography provides a powerful tool for the detection of calcium in the aortic wall of valve grafts. There is a low rate of calcification during the first 18 months in the Medtronic Freestyle valve, and this appears to be lower than that observed in homografts. Longer-term follow up of the aortic root in these patients is required. This is an ongoing study.

Adult↗

PubMed1997

Left ventricular aneurysmectomy; comparison between two techniques; early and late results.

OBJECTIVE: The aim of the present study was to evaluate early and late results of two different surgical techniques for left ventricular aneurysms repair. The conventional aneurysmectomy and direct closure of the ventricular wall and the endoventricular patch plasty. METHODS: We retrospectively reviewed 118 patients operated on for postinfarction left ventricular aneurysm from 1981 to 1994. Eighty-seven patients (Group A) were operated upon between 1981 and 1991 with the conventional technique and 31 patients (Group B) between 1992 and 1994 with the endoventricular patch plasty technique. Preoperative clinical, hemodynamic and echocardiographic evaluation with operative procedures and early postoperative results of all patients are reported. We also analyzed results of late clinical and echocardiographic controls of 34 patients of Group A and all patients of Group B after a mean follow-up of 42 and 28 months, respectively. RESULTS: Mean number of by-pass grafts was 1.9 in Group A and 2.6 in Group B (P = 0.01). The left anterior descending coronary artery was revascularized in 27 patients of Group A (34.6%) and 26 of Group B (89.7%) (P < 0.001); the left internal mammary artery was used in seven patients of Group A (8.9%) and 24 of Group B (82.8%) (P < 0.001). Hospital mortality in Group A was 10.3% (9/87), in Group B there was no hospital mortality (P > 0.05). Thirty-two patients of Group A (36.8%) and 3 of Group B (9.7%) suffered of low cardiac output syndrome (P = 0.01). At late control, improvements observed in NYHA and CCS classes, left ventricular ejection fraction (all P < 0.001 in both groups versus preoperative values) and left ventricular end-diastolic diameter (P > 0.05 in Group A and P < 0.001 in Group B) proved to be statistically higher in patients of Group B. CONCLUSIONS: Endoventricular patch plasty associated with a complete myocardial revascularization, in particular of the anterior descending coronary, and a larger use of the internal mammary artery, permits, by means of reconstruction of the left ventricular geometry, a better outcome for patients undergoing left ventricular aneurysmectomy.

Adult↗

PubMed1996

Ambulatory blood pressure and cardiac rhythm disturbances in elderly hypertensives: relation to left ventricular mass and filling pattern.

In order to define cardiac hypertensive involvement a group of 25 consecutive elderly male hypertensive outpatients and 25 age-matched male normotensive controls underwent full non-invasive assessment of cardiac status by resting 12-lead electrocardiography, Doppler-echocardiographic examination and simultaneous ambulatory blood pressure and electrocardiographic monitorings. Elderly hypertensives showed a higher prevalence of electrocardiographic left ventricular hypertrophy, an increased echocardiographic left ventricular mass, an impaired left ventricular filling pattern and more frequent ventricular arrhythmias when compared with normotensive controls. In elderly patients, left ventricular mass was found to be correlated with 24-hour ambulatory blood pressure (r = 0.47, p < 0.01) and 24-hour ambulatory blood pressure variability (r = 0.52, p < 0.01), while ventricular arrhythmias were correlated with left ventricular mass (r = 0.52, p < 0.01), the Doppler synthetic index of diastolic function E/A ratio (r = -0.56, p < 0.01) and both 24-hour systolic (r = 0.54, p < 0.01) and diastolic (r = 0.59, p < 0.01) ambulatory blood-pressure variabilities. These data suggest that hypertension induces in elderly patients an impairment of cardiac structure and function comparable with that already shown in younger hypertensives. Therefore, the assessment of hypertensive target-organ damage currently employed in younger subjects should be also considered in elderly hypertensives, at least when no other relevant medical disease is present.

Aged↗

PubMed1995

Blood pressure variations, hemorheological determinants, and platelet aggregation in hypertensive patients with unstable angina.

Plasma viscosity, fibrinogen, haematocrit and beta-thromboglobulin were assessed on venous blood samples taken within 24 hours of admission from 20 consecutive male hypertensive patients with unstable angina and 20 male hypertensive patients with stable angina, matched for clinical variables. Besides, all patients underwent automated indirect blood pressure monitoring for 24 hours, starting just after hospitalization. Despite similar average 24-hour, day-time and night-time systolic and diastolic blood pressure, hypertensive patients with unstable angina showed an increased variability of 24-hour (p <0.01) and day-time (p < 0.05) systolic and disatolic blood pressure, together with higher values of all haemorhelogical parameters (plasma viscosity, fibrinogen and haematocrit) (p < 0.01) and beta-thrombogobulin (p< 0.05), when compared with hypertensive patients with stable angina. Moreover, significant correlations between plasma viscosity and 24-hour systolic (r = 0.42, p < 0.01) and diastolic (r = 0.39, p < 0.05) blood pressure variability were shown in hypertensive patients with unstable angina. Besides, in the same patients, the haematocrit was positively correlated with 24-hour systolic blood pressure variability (r = 0.37, P < 0.05). Our data further support the relevance of rheological determinants, platelet activation and haemodynamic factors in the genesis of the high risk condition of unstable angina.

Aged↗

PubMed1995

Use of [123I]MIBG to assess cardiac adrenergic innervation: experience in hypertensive cardiopathy and left ventricular aneurysms.

[123I]MIBG has been proposed as a suitable tracer of the adrenergic system of the heart. The aims of this study was to investigate the adrenergic functional status of the heart in hypertensive patients with left ventricular hypertrophy (LVH), and to evaluate the distribution of neuroadrenergic terminals in patients with left ventricular aneurysms (LVA) presenting complex arrhythmias. We studied 21 patients (4 normals, 11 with LVH and hypertension, and 6 with previous myocardial infarction, LVA and complex arrhythmias) who underwent series of [123I]MIBG planar scans (from 0.5 to 24 hours p.i.) and SPECT scans using both [123I]MIBG and 201Tl. Data quantification was performed by calculating the heart/mediastinum ratio (planar scan) and the percent uptake in 5 myocardial regions (SPECT scan). No significant differences between normals and hypertensive patients were found either in the heart/mediastinum ratio or in the regional distribution of [123I]MIBG and 201Tl. In hypertensive patients the uptake of [123I]MIBG was significantly higher than that of 201Tl in the septal wall while in the lateral and inferior walls it was significantly lower. In patients with anteroapical myocardial infarction (MI), the size of the [123I]MIBG defect was slightly smaller than the 201Tl defect; moreover a constant, severe [123I]MIBG defect was observed in the inferior walls whereas 201Tl uptake was normal. We conclude that while in hypertensive patients adrenergic innervation seems to be slightly impaired as compared to myocardial perfusion, in patients with MI a large area of functional or anatomical denervation may be detected despite the preserved perfusion and viability; this mismatch may be the trigger of complex arrhythmias.

3-Iodobenzylguanidine↗

PubMed1993

Prevalence of silent ST segment depression during long-term ambulatory electrocardiographic monitoring in asymptomatic diabetic patients with essential hypertension.

Thirty-five asymptomatic diabetic patients with non insulin-dependent diabetes and mild moderate essential hypertension (18 males and 17 females, mean age 60 +/- 6 years) underwent echocardiographic examination, followed by simultaneous ambulatory blood pressure and electrocardiographic monitorings. Three hundred and sixteen significant episodes of asymptomatic ST segment depression (at least 1 mm 80 msec after the J point, lasting more than 1 min) were recorded in 21 patients (60%) with a total duration of 5637 minutes. Patients with asymptomatic episodes of ST segment depression had significantly higher values of total cholesterol (p < 0.05), LDL cholesterol (p < 0.05), Glycosylated hemoglobin (p < 0.001), left ventricular mass index (p < 0.02), mean 24-hour systolic and diastolic ambulatory blood pressure (p < 0.001), systolic (p < 0.02) and diastolic (p < 0.01) ambulatory blood pressure variability and hypertensive peaks (p < 0.05), with respect to the rest of the study population. The number of ST segment depression episodes was significantly related to total cholesterol levels (r = 0.40, p < 0.05), LDL cholesterol levels (r = 0.36, p < 0.05) glycosylated hemoglobin levels (r = 0.50, p < 0.01), left ventricular mass index (r = 0.48, p < 0.01), ambulatory systolic (r = 0.43, p < 0.01) and diastolic (r = 0.51, p < 0.01) blood pressure variability and hypertensive peaks (r = 0.50, p < 0.01). Our data suggest that haemodynamic and metabolic factors could have a relevant role in high prevalence of SMI in asymptomatic diabetic patients with EH. The evidence of SMI in these patients warrants further diagnostic work-up and prognostic assessment.

Aged↗

PubMed1992

Prevalence of left ventricular hypertrophy and cardiac arrhythmias in borderline hypertension.

Seventy-eight men with borderline hypertension according to the World Health Organization criteria underwent echocardiographic examination, followed by simultaneous ambulatory blood pressure and electrocardiographic monitorings for 24 h. The prevalence of echocardiographic left ventricular hypertrophy was 16.6% (13/78). Borderline hypertensives with left ventricular hypertrophy had more supraventricular (P less than .001) and ventricular ectopic beats (P less than .001) than normotensive controls and borderline hypertensives without cardiac involvement. Furthermore, ventricular ectopic activity was significantly related to left ventricular mass (r = 0.58, P less than .05) in borderline hypertensives showing echocardiographic evidence of left ventricular hypertrophy. Our findings suggest that noninvasive assessment of target organ status, including echocardiography, should be employed to optimize risk stratification in borderline hypertension.

Adult↗

PubMed1992

Target organ status and cardiovascular risk in borderline hypertension.

In order to assess the prevalence of target organ damage 78 men with borderline hypertension, according to the World Health Organization criteria, and 67 normotensive controls underwent echocardiographic, electrocardiographic and fundoscopic examination, followed by ambulatory blood pressure monitoring for 24 hours. Echocardiographic left ventricular hypertrophy was found in 13 borderline hypertensive subjects (16.6%), while no electrocardiographic or fundoscopic abnormalities could be detected. Our data suggest that noninvasive assessment of cardiovascular status, including echocardiography, allows recognition of a subset of borderline subjects with an increased risk for subsequent cardiac morbid events, thereby improving prognostic stratification.

Adult↗

PubMed1992

[The efficacy and tolerance of heparin-calcium at low doses in postinfarct ischemic cardiopathy].

The above study was undertaken in order to evaluate the efficacy and tolerability of low dose calcium heparin for postinfarct ischemic heart disease (CIPI). In particular, the incidence was checked of: cardiovascular death, reinfarction, angina pectoris, TIA or RIND, stroke, arterial thromboembolism, venous thromboses, heart failure, complex ventricular arrhythmias, silent myocardial ischemia. Eighty patients with CIPI were divided into two groups similar for age, sex, physical features, cardiovascular risk factors, site of infarction, length of hospitalization, complications during hospitalization, clinical and instrumental findings at discharge, concomitant pathology. Upon discharge, patients were randomized into group 1 for traditional treatment and group 2 which in addition received 12,000 U calcium heparin s.c. every 24 h. After 12 months, during which patients were submitted to periodical laboratory and instrumental (standard and dynamic ECG, echoG) evaluation, group 2 had significantly fewer cardiovascular events than group 1 both as to overall number of events and as to number of events per individual patient. Especially, silent myocardial ischemia and ventricular arrhythmias were less frequent in group 2 patients and these two events, especially if coincident, are known to have severe prognostic implications. The efficacy of low-dose calcium heparin must be attributed to the enhancement of physiological antithrombotic mechanisms with compensation of blood clotting disorders that are fairly frequent in CIPI patients. Long-term s.c. administration was well tolerated.

Aged↗

PubMedDate not supplied

[Effects of slow-release nicardipine on blood pressure, renal function and the renin-angiotensin-aldosterone system in patients with mild-to-moderate essential arterial hypertension].

The above study was intended to assess the efficacy of nicardipine in mild to moderate essential arterial hypertension and to check whether there are medium term changes in kidney function and urinary excretion of electrolytes in the course of nicardipine treatment. Twenty patients with mild to moderate essential arterial hypertension were treated daily with 40-80 mg doses of slow-release nicardipine after a wash-out period. Systolic and diastolic blood pressure was measured with traditional sphygmomanometer on entry and after 4, 8, and 12 weeks' treatment. Also, on entry and at conclusion of the study, the following parameters were measured: plasma renin activity, creatinine clearance, 24-hour urinary excretion of Na, K, Ca, and aldosterone. Nicardipine treatment was well tolerated and no significant changes of heart rate, creatinine clearance and urinary excretion of Na, K, Ca and aldosterone were observed after 12 weeks' treatment. The efficacy of nicardipine for the management of mild to moderate hypertension was thus confirmed. The absence of a natriuretic effect after 12 weeks' treatment goes to show that any diuretic action of the drug is irrelevant to its therapeutic effect which appears to be due mainly to its vasodilatory action.

Adult↗

PubMedDate not supplied

Left ventricular hypertrophy and diastolic dysfunction in alcohol-associated hypertension.

In order to assess left ventricular structure and diastolic function, 50 hypertensive male subjects, 25 with and 25 without a history of alcohol abuse, and 20 normotensive male controls underwent Doppler echocardiographic examination followed by ambulatory blood pressure monitoring for 24 hours. Left ventricular mass was significantly higher in alcoholic hypertensives in relation to non-alcoholic hypertensives (p < 0.05) and normotensive controls (p < 0.001). Moreover, Doppler parameters expressing left ventricular filling pattern were significantly worse in alcoholic than in non-alcoholic hypertensives (p < 0.01). Clinic and ambulatory blood pressure were similar in alcoholic and non-alcoholic hypertensives, while mean day-time heart rate was significantly higher in alcoholics (p < 0.01). Collected data suggest that non-hemodynamic factors are probably involved in the development of cardiovascular abnormalities in hypertensive alcoholics, and that echocardiography should be employed for risk-profile definition in alcohol-associated hypertension.

Alcoholism↗