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Biomedical subjects

G Habib

Publications and source records attributed to G Habib.

At least 73 records · Page 4Linked to original sources
PubMed1999

Value and limitations of the Duke criteria for the diagnosis of infective endocarditis.

OBJECTIVES: The purpose of this study was to assess the value and limitations of Duke criteria for the diagnosis of infective endocarditis (IE). BACKGROUND: Duke criteria have been shown to be more sensitive in diagnosing IE than the von Reyn criteria, but the diagnosis of IE remains difficult in some patients. METHODS: Both classifications were applied in 93 consecutive patients with pathologically proven IE. Blood cultures, and transthoracic and transesophageal echocardiography were performed in all patients. RESULTS: Sensitivities for the diagnosis of IE were 56% and 76% for von Reyn and Duke criteria, respectively. Fifty-two patients were correctly classified as "probable IE" by von Reyn and "definite IE" by Duke criteria (group 1). However, discrepancies were observed in 41 patients. Eleven patients (group 2) were misclassified as "rejected" by von Reyn, but were "definite IE" by Duke criteria; this difference could be explained by negative blood cultures and positive echocardiogram in all patients. In eight patients (group 3), the diagnosis of IE was "possible" by von Reyn but "definite" by Duke criteria. This difference was essentially explained by the failure of the von Reyn classification to consider echocardiographic abnormalities as major criteria. Twenty-two patients (group 4) were misclassified as possible IE using Duke criteria, being false negative of this classification. Echocardiographic major criteria were present in 19 patients, but blood cultures were negative in 21 patients. The cause of negative blood cultures was prior antibiotic therapy in 11 patients and Q-fever endocarditis diagnosed by positive serology in three cases. CONCLUSIONS: Twenty-four percent of patients with proved IE remain misclassified as "possible IE" despite the use of Duke criteria, especially in cases of culture-negative and Q-fever IE. Increasing the diagnostic value of echographic criteria in patients with prior antibiotic therapy and typical echocardiographic findings and considering the serologic diagnosis of Q fever as a major criterion would further improve the clinical diagnosis of IE.

Bacteria↗
PubMed1999

Effects of folate supplementation in hyperhomocysteinemic pigs.

OBJECTIVES: The aim of this study was to evaluate the therapeutic effects of folic acid in the pig model of hyperhomocysteinemia. BACKGROUND: We have previously shown that pigs fed a methionine-rich diet develop hyperhomocysteinemia, arterial lesions and thrombotic events. Elevated homocysteine level is an independent risk factor for atherosclerosis that can be markedly lowered with daily folic acid administration. However, it is not known whether this treatment can prevent arterial lesions. METHODS: Three groups of pigs were studied: 8 control subjects received a standard diet; 8 received a methionine-rich diet for four months; 8 received a methionine-rich diet for 1 month and then the methionine-rich diet + 5 mg/day folic acid for 3 months. At month 4 after hemodynamic investigation, all the pigs were sacrificed. RESULTS: Control animals developed few usual vascular streaks. All the pigs fed a methionine-rich diet without folic acid treatment developed hyperhomocysteinemia (10.3+/-1.3 micromol/liter at basal state, 18.2+/-2.5 micromol/liter at one month and 14.6+/-3.8 micromol/liter at four months), hemodynamic abnormalities and diffuse arterial lesions with smooth muscle cell hyperplasia, endothelial alterations and elastic lamina dislocation. In this group, one pig died of venous thromboembolism and one of myocardial infarction. The pigs fed a methionine-rich diet + folic acid displayed similar arterial lesions and two had thrombotic events (one myocardial infarction and one pulmonary embolism), despite normalization of homocysteine levels (10.9+/-1.3 micromol/liter at basal state, 19.5+/-2.5 micromol/liter at one month and 11.4+/-3.8 micromol/liter at four months). CONCLUSIONS: In the pig model of hyperhomocysteinemia, 5 mg/day folic acid did not prevent arterial lesions or thrombotic events.

Animals↗
PubMed1999

The effect of cimetidine on the pharmacodynamics of theophylline-induced seizures and ethanol hypnotic activity.

Due to its availability as an over-the-counter drug, the use of cimetidine is increasing, thus adverse interactions with other commonly used agents may also increase. The aim of this study was to investigate whether acute administration of cimetidine could alter the pharmacodynamics of theophylline neurotoxicity and the hypnotic action of ethanol. To examine these questions, rats received a dose of 77 mg/kg cimetidine followed by a constant infusion of either theophylline (1.2 mg/min.) or ethanol (16.3 mg/min.) until the onset of the pharmacological end point, maximal seizure or loss of righting reflex, where samples of blood and brain were obtained and assayed for either theophylline or ethanol. We report that cimetidine in doses that may cause pharmacokinetic interactions did not affect the concentration-effect relationship of either the stimulating action of theophylline or the depressant activity of ethanol. These outcomes emphasize the relative safety which patients using cimetidine in self-medication rely on.

Animals↗
PubMed1999

Silent myocardial ischemia in patients with diabetes: who to screen.

OBJECTIVE: Silent myocardial ischemia (SMI) is more common in diabetic patients than in the general population. However, the exact prevalence of SMI is not known, and routine screening is costly. The purpose of this 1-year study was to estimate the prevalence of SMI and define a high-risk diabetic population by systematically testing patients with no symptoms of coronary artery disease (CAD). RESEARCH DESIGN AND METHODS: The criteria for inclusion in this study were age (between 25 and 75 years), duration of diabetes (>15 years for type 1 diabetes, 10 years for type 2 diabetes with no cardiovascular risk factors, and 5 years for type 2 diabetes with at least one cardiovascular risk factor), and absence of clinical or electrocardiogram (ECG) symptoms of CAD. For 1 year, 203 patients were screened, including 28 women and 45 men with type 1 diabetes (aged 41.5+/-10.9 years, mean duration of diabetes 20.9+/-7.7 years [mean +/- SD]) and 61 women and 69 men with type 2 diabetes (aged 60.7+/-8.7 years, duration of diabetes 16.5+/-7.1 years). Exercise ECG was the first choice for screening method. If exercise ECG was not possible or inconclusive, thallium myocardial scintigraphy (TMS) with exercise testing and/or dipyridamole injection was performed. If any one of these tests was positive, coronary angiography was carried out and was considered to be positive with a stenosis of > or =50%. RESULTS: Positive screening results were obtained in 32 patients (15.7%). Coronary angiography demonstrated significant lesions in 19 patients (9.3%) and nonsignificant lesions in 7 patients (1 false-positive result for exercise ECG and 6 false-positive results for TMS). Coronary angiography was not performed in six patients. All but 3 of the 19 patients (15 men and 4 women) in whom silent coronary lesions were detected presented with type 2 diabetes. The main differences between the 16 type 2 diabetic patients presenting with coronary lesions and the type 2 diabetic patients without SMI were a higher prevalence of peripheral macroangiopathy (56.2 vs. 15.1%, respectively, P < 0.01) and a higher prevalence of retinopathy (P < 0.05). No correlation was found between SMI and duration of diabetes, HbA1c level, renal status, or cardiovascular risk factors except for family history of CAD. CONCLUSIONS: The results of this study allowed us to determine a high-risk group for SMI in the diabetic population. SMI with significant lesions occurs in 20.9% of type 2 diabetic male patients who are totally asymptomatic for CAD. Based on these findings, we recommend routine screening for male patients in whom the duration of type 2 diabetes is >10 years or even less when more than one cardiovascular risk factor is present.

Adult↗
PubMed1999

[Homocysteine and coronary events in coronary disease patients].

The objective of this study was to determine the prognostic value of serum homocysteine levels in patients with coronary heart disease. Homocysteine was assayed in 76 coronary patients with a mean age of 59.2 years hospitalized for myocardial ischaemia or myocardial infarction. Percutaneous transluminal angioplasty was performed in 47 (70%) of these patients during this hospitalization. The mean follow-up for these patients was 22 months (range: 11 to 67 months). In these patients, serum homocysteine levels were not correlated with the usual risk factors of coronary heart disease (age, sex, treated hypercholesterolaemia, smoking, diabetes) except for hypertension. It was strongly correlated with serum creatinine (R = 0.61; p = 0.0001). Eleven patients presented a major event during follow-up (8 deaths, 1 nonfatal myocardial infarction, 1 cardiac transplantation) and 16 underwent a revascularization procedure. The blood homocysteine level does not have any prognostic value for any coronary events. However, it is higher in patients who develop a major event than in those which do not (15.8 +/- 4 mumol/l versus 11.5 +/- 6.6 mumol/l, p = 0.05). Using multivariate analysis, taking into account age, serum creatinine and serum homocysteine, only serum homocysteine was predictive of major event-free survival (p = 0.02).

Adult↗
PubMed1998

[Six cases of acute rheumatic fever in one year].

During 1995, 6 cases of acute rheumatic fever were diagnosed here. Taking into account differences in total admissions, this appears to represent an increase over 1994. Most of the cases were males, with average age at diagnosis 19.5 years. All were of low socioeconomic status. 50% had cardiac involvement, and 1 needed treatment with corticosteroids. Most had pharyngeal symptoms prior to the acute attack, and 1 patient had 2 prior episodes of rheumatic fever. A thorough epidemiological study should be done in the Nazareth area to assess the real incidence of acute rheumatic fever, and to determine whether there is a true increase in incidence.

Acute Disease↗
PubMed1998

Additional antianginal and anti-ischemic efficacy of mibefradil in patients concomitantly treated with long-acting nitrates for chronic stable angina pectoris.

BACKGROUND: Mibefradil, a newly approved antihypertensive and antianginal drug, is the first member of a new class of calcium antagonists (CAs), the tetralol derivatives, that selectively blocks T-type Ca2+ channels in contrast to classical CAs which, at therapeutic concentrations, block only L-type Ca2+ channels. Since patients with chronic stable angina pectoris typically may be treated with the combination of a long-acting nitrate and a CA, the additive efficacy and safety of mibefradil in combination with nitrate therapy needs to be determined. HYPOTHESIS: This study was designed to assess the efficacy, tolerability, and safety of mibefradil when added to long-acting nitrate therapy in patients with chronic stable angina pectoris. METHODS: Following a 1-week placebo run-in period, patients were randomized to receive either mibefradil 50 mg (n = 96) or placebo (n = 93) once daily in addition to their nitrate therapy. After 2 weeks of active treatment, patients receiving the mibefradil were force titrated to 150 mg once daily for an additional 2 weeks. Exercise tolerance tests (ETTs) were performed at the end of Weeks 2 and 4; patients also maintained an anginal diary during the 4-week treatment period. RESULTS: After 2 weeks of treatment with 50 mg mibefradil (within the current recommended dose range), a statistically significant but modest increase in total exercise duration was observed (treatment effect 16.4 s, p = 0.04). Similarly, there was a significant increase in time to onset of ischemia (treatment effect 26 s, p = 0.008). The adverse event profile of the 50 mg dose was indistinguishable from placebo, indicating that this dose was extremely well tolerated. At Week 4, the mibefradil-treated patients were taking 150 mg, which is above the current recommended dose range. The increase in total exercise duration was larger for the mibefradil 150 mg group than for the placebo group. For the intent-to-treat population, this difference did not reach statistical significance, whereas in the standard population it did (treatment effect 21 s, p = 0.05). The other two ETT variables, time to onset of angina and time to onset of 1 mm ST-segment depression, demonstrated significantly greater effect with mibefradil 150 mg (treatment effects 40 s, p = 0.002, and 55 s, p < 0.001, respectively, for the intent-to-treat population). Mibefradil 150 mg was associated with more adverse events than placebo, specifically, dizziness, leg edema, and postural hypotension. CONCLUSIONS: This study demonstrates that mibefradil 50 mg once daily in the setting of the background long-acting nitrate therapy produces additive antianginal and anti-ischemic effects and is extremely well tolerated.

Adolescent↗
PubMed1998

Association of mild hyperhomocysteinemia with cardiac graft vascular disease.

In non-transplant patients mild hyperhomocysteinemia is an independent risk factor for vascular disease. The aim of this study was to determine whether hyperhomocysteinemia is associated with graft vascular disease. Fasting total plasma homocysteine was assessed in 18 patients with graft vasculopathy and 18 transplanted patients without graft vasculopathy matched for age, sex and the time since transplant. All were on cyclosporin. Graft vasculopathy was defined at coronary angiography as stenoses > or = 25%, or aneurysms. We found that hyperhomocysteinemia ( > or = 15 micromol/l) is common among transplanted heart recipients and significantly more frequent in the patients with graft vasculopathy (17/18 versus 11/18). Accordingly, the mean homocysteinemia was significantly higher in the group with graft vasculopathy (23.6+/-7.8 versus 16.9+/-7.1 micromol/l, P=0.01). The elevation of homocysteine plasma levels in the heart transplant recipients has probably multiple causes. The main cause seems to be renal failure. Additional causes could be azathioprine treatment or genetic polymorphisms. These results suggest that besides the immunological factors, homocysteine can play an additional role in the pathogenesis of graft vascular disease.

Adult↗
PubMed1998

Decompression induced venous gas emboli in sport diving: detection with 2D echocardiography and pulsed Doppler.

The aim of this study was to determine the utility of pulsed Doppler and 2D echocardiography for the detection and the quantification of circulating bubbles after decompression. Twenty-three sport divers performed 60 SCUBA dives (mean 32 msw). An evaluation of circulating bubbles was performed using 2D images one hour after diving. Circulating bubbles were also detected with pulsed Doppler. The sample volume was placed in the outflow area of the right ventricle 1-2 cm below the pulmonary valve. 2D echocardiography showed circulating bubbles in right cavities of the heart in 32 cases. Short axis parasternal view and right cavities long axis view were the best incidences. Pulsed Doppler confirmed the results in these 32 cases and detected circulating bubbles in seven other cases. Isometric contraction of muscle limb must be performed to increase the sensitivity of detection. The count of the bubbles may be evaluated when using a combination of Spencer's and Powell's grading. We conclude that 2D echocardiography is less accurate than pulsed Doppler in the detection of circulating bubbles after decompression. Further studies are needed to compare pulsed Doppler guided by 2D echocardiography to continuous Doppler for the detection of circulating bubbles.

Adult↗
PubMed1998

[ECG anomalies and axis deviations in heart transplant recipients: MRI studies].

The electrocardiogram is often abnormal after orthotopic cardiac transplantation. This study was conducted in order to evaluate the frequency of these abnormalities in a population of 29 patients transplanted according to the conventional mode or the total mode. We also investigated the correlation between these abnormalities and the presence of left ventricular hypertrophy or deviation of the left ventricular long axis. The left ventricular mass was measured by TM echocardiography. The position of the left ventricular long axis was determined by MR on a ultrarapid sequence. The ECG was normal in 5 patients. The abnormalities revealed in the other 24 patients were: an rSr' or rsr' appearance in V1 with a QRS complex less than 0.12 sec in 11 patients, complete right block in 1 patients, repolarization abnormalities (apart from those associated with branch blocks) in 8 patients, left axis deviation of the QRS in 5 patients, a biphasic P wave in V1 with a Morris index greater than 4 mV.sec in 5 patients, and double atrial activity in 3 patients. These abnormalities were observed regardless of the type of transplantation, with the exception of double atrial activity which was only observed in the group of patients undergoing conventional transplantation. On average, the long axis of the left ventricle was more horizontal and deviated to the left compared to age- and sex-matched controls. All patients with left axis deviation of the QRS had left ventricular hypertrophy versus 13 of the 24 patients without QRS axis deviation and abnormalities of position of the anatomical left ventricular long axis. Our results therefore suggest that the frequent presence of right branch block in heart transplant recipients is due to factors other than the position of the heart in the thorax, for example right ventricular hypertrophy.

Adult↗
PubMed1998

[Infectious endocarditis, did it change?].

Although the incidence and prognosis of infectious endocarditis have remained relatively stable for many years, this disease has recently undergone major modifications of its aetiological and bacteriological profiles, and has benefited from progress in echocardiographic techniques. New diagnostic criteria have been proposed and considerable therapeutic progress has been accomplished, in both medical (antibiotic therapy) and surgical (conservative surgery, homografts) modalities.

Echocardiography↗
PubMed1997

Reappraisal of the importance of heart rate as a risk factor for cardiovascular morbidity and mortality.

Heart rate is a key determinant of myocardial oxygen consumption. Several lines of evidence support a consistent association between heart rate and cardiovascular mortality. Increments in heart rate are positively related to cardiovascular and sudden death in patients with hypertension or previous myocardial infarction and in the elderly with heart disease. This relationship is important because a number of commonly used cardiovascular agents, such as beta-blockers and calcium antagonists (CAs), can affect heart rate. Beta-blockers decrease heart rate and reduce morbidity and mortality in post-myocardial infarction patients. The CAs are a structurally diverse group of agents with different physiologic effects. The dihydropyridine CAs are not associated with a reduction in heart rate. In fact, often they can cause reflex tachycardia as a result of potent systemic vasodilator action, which may provoke angina, especially in patients with ischemic heart disease. The nondihydropyridine CAs verapamil and diltiazem reduce heart rate but are associated with negative inotropy. Mibefradil, the first member of a new class of CAs, reduces heart rate and is not associated with negative inotropic effects. This unique pharmacologic profile may be of great value in treating hypertensive patients, particularly those with coexisting ischemic heart disease, and also patients with angina pectoris alone. However, the clinical benefit of pharmacologically reducing heart rate with mibefradil needs to be demonstrated in controlled trials.

Adrenergic beta-Antagonists↗
PubMed1997

[Edema caused by retroperitoneal and tricuspid fibrosis with sclerodermatous cutaneous involvement disclosing carcinoid tumor. Apropos of a case and review of the literature].

A 65-year-old female was admitted with leg edema by retroperitoneal fibrosis and tricuspid valve incompetence by fibrosis, cutaneous fibrosis, moderate flushing over the upper body without diarrhea. It revealed an ileal carcinoid tumor with hepatic metastases. Octreotide (Sandostatine), tumor excision and interferon alpha 2b treatment led to a regression of flushing and edema, a reduction of fibrosis and a stabilization of the metastatic carcinoid, with normal serotonin levels.

Aged↗
PubMed1997

Aortic valve or root replacement with cryopreserved homograft for active infectious endocarditis.

Active aortic endocarditis is a serious condition that carries a high mortality and morbidity. The aim of this study was to analyse results obtained from 24 patients who underwent aortic valve or root replacement with cryopreserved homograft for aortic endocarditis. Eleven patients had native valve endocarditis, and 13 had prosthetic valve endocarditis. The mean age was 47.7 years: there were seven women and 17 men. Causative organisms were staphylococci (12), streptococci (four), serratia (one), candida (one), pneumococci (one), while no organisms were isolated in the remaining five patients. Complete reconstruction of the aortic annulus with homograft conduits was necessary in 20 patients (six total root and 14 mini-root). Infracoronary homograft aortic valve replacement was performed in the remaining patients. One patient died 1 day after the operation from ventricular failure, and two others died after 4 and 6 months as a result of arrhythmia. One patient died of recurrent endocarditis 1 year after surgery. The actuarial survival rate at 3 years was 83.4%. All survivors are symptom-free, with no evidence of recurrent endocarditis. Doppler echocardiography showed minimal aortic regurgitation in four patients.

Adult↗
PubMed1997

[Use of aortic valve homografts in adults].

Although the first implantations of homologous aortic valve grafts were performed many years ago, there has been a recent renewed interest in these valve replacements particularly as a result of progress in cryopreservation techniques and the development of homograft banks. Homografts have many advantages: low incidence of thromboembolic complications, no need for anticoagulant treatment, excellent haemodynamic performance and resistance to infection which make them the valve replacement of choice in the case of endocarditis, particularly in the presence of an abscess of the aortic cuff. However, their disadvantages concern their limited availability, a more difficult operative technique, a risk of postoperative aortic incompetence and the possibility of long-term degeneration. However, the most recent studies show that homografts have a longer life-span than bioprostheses, particularly in young subjects in whom 70% of cryopreserved homografts remain free of degeneration after 15 years. If these encouraging results are confirmed, implantation of a homograft could be considered to be an alternative to valve replacement by mechanical prosthesis in this age group. Other studies, especially comparative studies versus mechanical prostheses, are required in order to extend the indications of homograft aortic valves.

Adult↗
PubMed1997

[A comparative study of standard and total orthotopic cardiac transplantation].

The classical orthotopic heart transplant modifies size and geometry of the atria, may affect mitral and tricuspid function, and ventricular filling. A technical modification with subtotal excision of the recipient's heart, with anastomosis of a cuff of left atrium and of venae cavae has been used and compared with 2 consecutive series of transplantations : 70 classical (group I) 1986-1991, and 50 modified (group II) 1992-1994. The patients were similar for age, pretransplant characteristics, postoperative treatment. The aortic cross-clamping in the recipient (duration of cardiac excision and graft implantation) has been longer in group II (87 +/- 19 mm vs 65 +/- 15: p < 0.001). No surgical complication due to the technique was observed. Mortality was similar in the 2 groups (14% group I, 18% group II; NS). Five patients of group I has a systemic embolism (1 month to 5 years after transplant), none in group II. Two comparable groups of 30 patients were studied at least 6 months after transplantation with: surface EKG, Holter, transthoracic and esophageal echodoppler. A larger number of EKG anomalies, a significant increase in the size of atria, a significantly larger number of mitral and tricuspid insufficiencies, an increase in the variability of E/A ratio (left ventricular filling parameter) were noted after classical transplantation. Spontaneous contrast echo and thrombus in the left atrium were also noted after classical transplant. We conclude that these technical modifications result in a geometry and anatomy closer to normal. Less anomalies of the cardiac function were found. Due to the absence of left atrial thrombus and of systemic embolism we think that there is a definite advantage in this technically rather simple approach.

Actuarial Analysis↗
PubMed1997

[Quantification of mitral regurgitation by cine-MRI. Comparison with transesophageal echocardiography in 45 patients].

Cine-MRI demonstrates the presence of mitral regurgitation by a signal void. This study was undertaken to assess the value of this method for quantification of mitral regurgitation in a population not excluding either patients with mitral valve prostheses or those with atrial fibrillation. The subjects included had a mean age of 59 years and were referred for transoesophageal echocardiography, either for assessment of valvular heart disease (38 patients), or for detection of atrial thrombosis before external electrical cardioversion (7 patients). Eight patients had mitral valve prostheses and 19 were in atrial fibrillation. Cine-MRI was performed within 12 days of the transoesophageal echocardiography study with a 1.5 tesla magnet, using a sequence of gradient echo in 3 parallel planes in the 4 chamber view. The regurgitation was quantified by MRI from the extension of the signal void in the left atrium. The transoesophageal Doppler echocardiographic criteria were the width of the regurgitant jet at its origin, the intensity of the regurgitation signal recorded by continuous wave Doppler and the extension of the jet within the left atrium. The quantification by degrees 1 to 4 did not differ by more than 1 degree between the 2 techniques in 43 of the 45 patients. Out of 4 left atrial thrombus detected by transoesophageal echocardiography, only 1 was visible by MRI. The authors concluded that quantification of mitral regurgitation by cine-MRI provides similar results to those obtained by transoesophageal echocardiography and that the correlation remains valid in cases of atrial fibrillation. However, Doppler echocardiography provides further valuable information for the clinician.

Aged↗