PubMed Health⌕ Search

Biomedical subjects

J C Potier

Publications and source records attributed to J C Potier.

At least 19 recordsLinked to original sources
PubMed2000

Improvement of cardiac neuronal function after carvedilol treatment in dilated cardiomyopathy: a 123I-MIBG scintigraphic study.

UNLABELLED: Carvedilol can induce important clinical and hemodynamic improvements in patients with chronic heart failure resulting from severe left ventricular (LV) dysfunction. This study examines the impact of carvedilol on cardiac neuronal function using 123I-metaiodobenzylguanidine (MIBG) scintigraphy in dilated cardiomyopathy. METHODS: Twenty-two patients with chronic heart failure (19 men, 3 women; mean age, 54 y; age range, 34-64 y) assessed as New York Hospital Association (NYHA) class II or III and with initial resting radionuclide LV ejection fractions (LVEF) < 0.40 were enrolled in the study. Patients had long histories of symptomatic LV dysfunction despite optimal diuretics and angiotensin-converting enzyme inhibitor treatment. Over a 6-mo period, 50 mg/day carvedilol was administered to these patients. Planar 123I-MIBG scintigraphy provided measurements of cardiac neuronal uptake (as heart-to-mediastinum count activity ratio [HMR]), 4h after intravenous injection of 185 MBq MIBG. Hemodynamic, clinical, radionuclide LVEF and HMR data measured at the outset and after 6 mo of carvedilol were compared. RESULTS: Resting heart rate decreased from 81 +/- 13 to 71 +/- 9 bpm (P = 0.003). After carvedilol therapy NYHA functional classification for these patients improved from 2.6 +/- 0.5 to 2.3 +/-0.5 (P = 0.04), LVEF improved from 22% +/- 9% to 30% +/- 13% (P = 0.005), and HMR improved from 145% +/- 23% to 170% +/- 25% (P = 0.0001). CONCLUSION: Carvedilol induces improvements of clinical symptoms and cardiac neuronal and systolic functions in patients with dilated cardiomyopathy and chronic optimal treatment.

3-Iodobenzylguanidine↗
PubMed1999

Direct coronary stenting without balloon predilation in acute coronary syndromes.

BACKGROUND: This prospective, observational study was designed to evaluate the feasibility and the safety of a new strategy for stenting in acute coronary syndromes: direct stent implantation without predilation of the culprit lesion. This strategy might reduce both the cost of the procedure and the rate of no-reflow, a phenomenon that is more frequently observed during dilation of unstable plaques. METHODS AND RESULTS: Between September 1997 and March 1998, 122 carefully selected patients with unstable angina or acute myocardial infarction were included in this study. Highly calcified lesions and vessels with excessive proximal tortuosity were excluded. The procedure was successful in 96% of cases. In 5 cases the stent failed to pass through the stenosis and was successfully retrieved in the guiding catheter in 3 cases. In 2 cases the stent was lost in the peripheral circulation. Transient no-reflow occurred in only 3 cases and was rapidly reversed by rescue use of an intracoronary bolus injection of a glycoprotein IIb/IIIa receptor inhibitor in 2 cases. A patient treated by primary angioplasty with cardiogenic shock on admission died 48 hours after the initial procedure because of irreversible cardiac failure. One-month clinical follow-up was obtained by telephone for all patients; no major coronary events occurred during this period. CONCLUSIONS: Direct coronary stenting without balloon predilation can be safely performed in acute coronary syndrome-related lesions in selected patients. A randomized, controlled study is warranted to confirm the promising results of this pilot study, especially regarding the low rate of the no-reflow phenomenon.

Aged↗
PubMed1999

Detection of cardiac myxoma by F-18 FDG PET.

Intracardiac tumors occur infrequently and are difficult to diagnose with CT and MRI. The authors describe the successful imaging of a right atrial myxoma with F-18 FDG PET.

Fluorine Radioisotopes↗
PubMed1999

The reversibility of cardiac neuronal function after removal of a pheochromocytoma: an I-123 MIBG Scintigraphic Study.

PURPOSE: Twelve patients with proved pheochromocytoma evaluated in our institution between 1991 and 1997 are described. METHODS: The patients' urinary excretion rates and their metabolites (vanylmandelic acid and metanephrines) were significantly greater than normal before surgery. Echocardiography showed normal left ventricular ejection fractions (72% +/- 8%). All of the patients underwent planar I-123 metaiodobenzylguanidine (MIBG) scintigraphy to assess cardiac neuronal uptake 4 hours after and locate a pheochromocytoma 24 hours after intravenous injection of 185 MBq (3 mCi) I-231 MIBG. Ten patients with pheochromocytoma had positive tumoral findings with I-123 MIBG scintigraphy. Twelve patients had significant impairment of cardiac neuronal uptake of MIBG, with a heart:mediastinum ratio averaging 142% +/- 18% (normal value, 230% +/- 30%, P < 0.05). Postoperative cardiac MIBG imaging was performed in all patients (at 6 +/- 3 months). RESULTS: After surgical removal of the pheochromocytoma, cardiac MIBG uptake and the heart:mediastinum uptake ratios improved significantly (197% +/- 20%, P < 0.05) in all the patients. Urinary excretion rates and metabolites returned to the normal range. However, no significant correlation was found between cardiac MIBG uptake and urinary excretion rates and metabolites after the tumors were removed. CONCLUSION: Removing a pheochromocytoma reversed cardiac neuronal function as assessed by MIBG scintigraphy.

3-Iodobenzylguanidine↗
PubMed1999

[Treatment of refractory cardiac insufficiency by peritoneal ultrafiltration. Literature review].

The management of heart failure that has become refractory to conventional drug treatment is an increasingly frequent problem for clinicians. Peritoneal dialysis, by ultrafiltration, is an effective method to treat refractory oedema, thereby improving the functional symptoms of these patients. The objective of this article is to review the data, of the literature and to define the results and indications of this treatment, which still remains and exceptional modality.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Impact of exercise rehabilitation on cardiac neuronal function in heart failure: an iodine-123 metaiodobenzylguanidine scintigraphy study.

Exercise training can induce important haemodynamic and metabolic adaptations in patients with chronic heart failure due to severe left ventricular dysfunction. This study examined the impact of exercise rehabilitation on cardiac neuronal function using iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy, Fourteen patients (11 men, 3 women; mean age 48 years; range: 36-66 years) with stable chronic heart failure of NYHA class II-III and an initial resting radionuclide left ventricular ejection fraction (LVEF) < 50% were enrolled in the study. Patients underwent progressive, supervised endurance training (treadmill test, Bruce protocol) during a 6-month period (60 sessions, 3 sessions per week) at a cardiac rehabilitation referral centre in order to measure exercise parameters. Planar 123I-MIBG scintigraphy provided measurements of cardiac neuronal uptake (heart-mediastinum ratio activity, 4 h after intravenous injection of 185 MBq of MIBG). Radionuclide LVEF was also assessed at the outset and after 6 months of exercise training. Workload (801 +/- 428 vs 1229 +/- 245 kpm.min-1, P = 0.001), exercise duration (504 +/- 190 vs 649 +/- 125 s, P = 0.02), and myocardial MIBG uptake (135% +/- 19% vs 156% +/- 25%, P = 0.02) increased significantly after rehabilitation. However, LVEF did not change significantly (23% +/- 9% vs 21% +/- 10%, p = NS). It is concluded that exercise rehabilitation induces improvement of cardiac neuronal function without having negative effects on cardiac contractility in patients with stable chronic heart failure.

3-Iodobenzylguanidine↗
PubMed1998

Proarrhythmic and antiarrhythmic effects of bupivacaine in an in vitro model of myocardial ischemia and reperfusion.

BACKGROUND: Bupivacaine may have toxic cardiovascular effects when accidentally administered by intravascular injection. However, its electrophysiologic effects in the presence of myocardial ischemia remain unknown. The authors evaluated the electrophysiologic and anti- and proarrhythmic effects of bupivacaine in an in vitro model of the ischemic and reperfused myocardium. METHODS: In a double-chamber bath, a guinea pig right ventricular muscle strip was subjected partly to normal conditions and partly to simulated ischemia followed by reperfusion. The electrophysiologic effects of bupivacaine were studied at 1, 5, and 10 microM concentrations. RESULTS: Bupivacaine (5 and 10 microM) decreased the maximal upstroke velocity of the action potential (Vmax) in normoxic conditions and further decreased (10 microM) the Vmax decrease induced by ischemic conditions. Bupivacaine reduced the mean occurrence time to the onset of myocardial conduction blocks (9 +/- 3 min; mean +/- SD; P < 0.005 with 5 and 10 microM, compared with 17 +/- 6 min during simulated ischemia with no drug or control), and it increased the number of preparations that became inexcitable to pacing (55% of preparations, with 1 microM and 100% with 5 and 10 microM, compared with 17% for the control group). The incidence of spontaneous arrhythmias was reduced by 5 and 10 microM bupivacaine during ischemia and reperfusion and was enhanced by 1 microM bupivacaine during the ischemic phase. CONCLUSIONS: In guinea pig myocardium under ischemic conditions, bupivacaine induced a loss of excitability at concentrations of 5 and 10 microM. Proarrhythmic effects observed at 1 microM were considered as lower than the cardiotoxic range in normoxic conditions. The incidence of reperfusion arrhythmias was decreased at all concentrations.

Action Potentials↗
PubMed1998

Pharmacological approaches to the prevention of restenosis after coronary angioplasty.

Restenosis in the months following a successful percutaneous transluminal coronary angioplasty (PTCA) remains the main limitation to this technique for myocardial revascularisation. Despite intensive investigation in this area, no pharmacological therapy has yet been found to be useful in preventing restenosis after conventional balloon angioplasty. The occurrence of restenosis, which is now known to be caused by both vessel remodelling and neointimal hyperplasia, might be reduced in the future by a combined mechanical and pharmacological approach. Although systemic administration of 'antirestenosis' drugs has not yet been tested to prevent restenosis after coronary stenting, it is very likely that pharmacological inhibition of neointimal hyperplasia within coronary stents will take advantage of local delivery techniques. In addition to local drug delivery catheters that are available, the stent itself may be coated with polymers and serve as a platform for drug delivery. The continued attractiveness of PTCA, as an alternative to medical treatment or bypass surgery for patients with coronary artery disease, will depend upon our ability to control the restenotic process.

Angioplasty, Balloon, Coronary↗
PubMed1998

Iodine-123-metaiodobenzylguanidine SPECT of regional cardiac adrenergic denervation in Brugada syndrome.

We present the case of 44-yr-old man who presented syncope with ventricular tachycardia in the setting of Brugada syndrome. In addition to the electrocardiographic evidence of the syndrome and the absence of apparent structural heart disease, clear defects of myocardial neuronal metaiodobenzylguanidine (MIBG) uptake on MIBG SPECT imaging also were found in inferior, apical and septal walls. Thallium-201 SPECT distribution was homogeneous along the left ventricle. Thus, cardiac MIBG scintigraphy provides information about left ventricular dysinnervation in a patient with Brugada syndrome, enhancing the clinical utility of myocardial MIBG SPECT imaging in life-threatening ventricular arrhythmias.

3-Iodobenzylguanidine↗
PubMed1998

[Ehlers-Danlos disease revealed during pregnancy through the diagnosis of aortic dissection].

Dissection of the aorta is a serious condition but rare in young women, and occurring during the 3rd trimester of pregnancy. The main risk factors are hypertension and diseases of the connective tissue or of collagen (Marfan's syndrome and Ehlers-Danlos disease). The authors report a case of dissection of the aorta managed in a pluridisciplinary manner by the anaesthetists, cardiologists, obstetricians and cardiothoracic surgeons, which resulted in a favourable outcome for both mother and baby. The diagnosis of Ehlers-Danlos disease was made from the onset and, over a period of 10 years with CT scan and annual echocardiographic follow-up, total replacement of the supra-coronary aorta was performed in several stages.

Adult↗
PubMed1998

[Current status of post-infarction cardiogenic shock and revascularization].

Despite improved management of myocardial infarction, the incidence of cardiogenic shock remains constant at about 7.5% of cases. Patients who develop cardiogenic shock are older and much more often women. The site of infarction is usually anterior, transmural with greater left ventricular systolic dysfunction and a higher increase in cardiac enzymes. Diastolic intra-aortic balloon pumping is the usual treatment but survival only seems to be increased in patients undergoing revascularisation. Surgical revascularisation and circulatory assist devices have been proposed but patient selection in these studies was biased and optimised the results. The effect of thrombolysis was analysed in a subgroup of patients in the GISSI study. The 30 day mortality was 69.9% in 146 patients treated by streptokinase and 70.1% in patients given placebo. Thrombolysis only benefitted patients with an anterior myocardial infarction aged less than 65 and treated within 6 hours of the onset of pain. Although there are no randomised studies of the value of angioplasty in patients in cardiogenic shock. Several uncontrolled series suggest that this type of procedure reduces short and long-term mortality. However, the prognosis is not as good when unselected consecutive groups of patients are studied in whom infarction is complicated by cardiogenic shock immediately and who undergo "aggressive" revascularisation: 72% of patients die in hospital and there are few long-term survivors. The prognosis appears to be particularly poor in patients over 70 years of age with a previous history of myocardial infarction or who undergo prolonged pre-hospital cardiopulmonary resuscitation. However, the implantation of coronary stents associated with circulatory assist devices seems to improve the prognosis of infarction complicated by cardiogenic shock by ensuring adequate coronary flow and reducing the risk of reocclusion.

Adult↗
PubMed1998

Impairment of cardiac neuronal function in acute myocarditis: iodine-123-MIBG scintigraphy study.

UNLABELLED: Abnormalities of norepinephrine uptake have been found to reflect impairment in adrenergic nerve function that has influenced the cardiac outcome of patients with heart failure. The aim of this study was to explore the cardiac neuronal function by using 123I-metaiodobenzylguanidine (MIBG) scintigraphy in patients with acute myocarditis. METHODS: We studied 15 patients (age range 42 +/- 10 yr) with clinical, biological, electrocardiographic and radionuclide left ventricular ejection fraction (LVEF) (41% +/- 7%) data indicating myocarditis and 10 normal subjects (age range 36 +/- 7 yr, mean radionuclide LVEF 69% +/- 8%, p < 0.05). Fourteen patients had positive histologic findings of myocarditis and 1 had nonspecific histological data. All patients underwent planar cardiac imaging after intravenous injection of 185 MBq 123I-MIBG and right ventricular biopsy within 7 days. A chest anterior view was acquired 4 hr later. Heart-to-mediastinum ratio activity was measured, as previously described in our laboratory. RESULTS: Significant impairment of cardiac neuronal uptake of MIBG was observed and based on a reduction of heart-to-mediastinum ratio (148% +/- 16% versus 234% +/- 36%, p < 0.05). A significant correlation was observed between LVEF and MIBG uptake in patients (y = 1.58x +/- 83.7, r = 0.72, p < 0.01). CONCLUSION: Acute myocarditis is associated with an injury of the cardiac adrenergic neuronal function. In addition to the inflammatory injury of the myocytes, the impairment of adrenergic function may be involved in the cardiac pump failure induced by myocarditis.

3-Iodobenzylguanidine↗
PubMed1997

Peritoneal ultrafiltration and refractory congestive heart failure.

This prospective nonrandomized study enrolled 16 patients with congestive heart failure [NYHA (New York Heart Association) III and IV] refractory to a maximal well-tolerated drug therapy. The aims were to evaluate if peritoneal ultrafiltration (PUF) could improve clinical conditions and to determine morbidity secondary to resistant congestive heart failure (RCHF) and PUF. There were 16 patients (12 male, 4 female) with a mean age of 65.4 years (56-81 years) and follow-up of 15.6 months (4-33 months). Thirteen patients had RCHF without end-stage renal disease. Patients were classified as NYHA class IV (n = 11) or class III (n = 5). One anuric patient had been on previous hemodialysis and switched to APD. PUF was obtained with a 2-L hypertonic dialysis solution, once a day (n = 7) or every 2 days (n = 4). Clinical improvement was obtained for all the patients. Weight decreased from 72.2 to 66.7 kg with a weekly ultrafiltration of 3.74 L (2.2-6.5 L). Sodium removal was 79 mmol/day (urinary 43%, peritoneal transport 57%). During the follow-up period, 2 patients received a cardiac transplant since 7 died due to cardiac reasons. Mean hospitalization time was 4.4 and 1.20 per patient per day before and after PUF, respectively. Hospitalization was in keeping with either RCHF (36%), dialysis complications (16%), or miscellaneous causes (48%). Our experience showed that a functional improvement and a better quality of life were achieved for all these patients with a low rate of hospitalization.

Aged↗
PubMed1996

[Cardiac transplantation. Evaluation of a consecutive series of 75 grafts].

OBJECTIVES: The global results of various series of heart transplantation (HT) are essential to assess the life expectancy provided by this technique. Due to the increasing graft shortage, it appears essential to very strictly candidates for HT. METHODS: From March 8, 1989 to December 7, 1994, 75 orthotopic Hts were performed in 62 men and 12 women (1 case of retransplantation). The mean age was 47.46 +/- 15.02 years (range: 2.5-66 years). Four patients were younger than 10 years and 22 were older than 60 years. Our series included more cases of ischaemic heart disease (36) than dilated cardiomyopathies (33), with a history of cardiac surgery in almost one quarter (20) of patients with ischaemic heart disease. RESULTS: The immediate postoperative survival rate was 94.7% with 3 deaths attributable to refractory pulmonary hypertension associated with graft failure and one death related to postoperative tamponade. Five other patients died during the following 3 months, increasing the mean global survival to 88%. After a mean follow-up of 2.1 years (maximum 5.8 years), the actuarial 5-year survival rate was 56.8%. Eleven patients died between 4 and 38 months (mean: 18.2 months). Two deaths were due to cancers, 4 were due to septicaemia, another 4 were due to rejection and finally 1 was due to meningeal haemorrhage. The frequency (19) of reoperations for clot removal was due to the large number of patients with a history of previous heart surgery (20). CONCLUSION: Strict recipient selection, possibly based on 123I-MIBG scintigraphy, the use of pulsatile circulatory assistance systems, improved CMV, morphometry and donor-recipient age matching, should optimize the results of a technique, whose efficacy is confirmed in this series.

Adolescent↗
PubMed1996

[Effects of temporary dual-chamber cardiac pacing in refractory cardiac failure].

The authors studied 18 patients (15 men, 3 women) with an average age of 67 +/- 8 years with refractory cardiac failure. In order to determine the potential of pacing to raise cardiac output in severe cardiac failure. The average ejection fraction was 26 +/- 6.5%. All patients were in sinus rhythm:resting cardiac output was 3.35 l/min. Two temporary pacing catheters were positioned in the right atrium and at the apex of the right ventricle for dual-chamber mode pacing triggered by the spontaneous P waves. Changes in cardiac output were measured by Doppler echocardiography at different values of atrioventricular delay. Patients were considered to be responders if their cardiac outputs rose by 15%. In 7 patients meeting this criterion, the average increase in cardiac output was 27% (2.99 +/- 0.7 to 3.81 +/- 0.86 l/mn; p < 0.01); all had dilated cardiomyopathies with left bundle branch block and the optimal AV delay was 103 +/- 21 ms (80-140 ms); the duration of diastolic filling increased from 212 +/- 98 to 292 +/- 116 ms (p = 0.02). In the non-responding group (11 patients with an increase of cardiac output of only 3.6 +/- 0.09 to 3.9 +/- 0.92 l/mn; p < 0.01), the underlying disease process was mainly ischaemic. Two predictive factors of efficacy of dual-chamber pacing were identified: a short ventricular filling period (29 +/- 8% of the RR interval in the responders vs 44 +/- 9% in the non-responders; p < 0.01) and the presence of 1st degree atrioventricular block. Dual-chamber pacing could be a valuable method of increasing resting cardiac outputs in a selected group of patients with severe, refractory, cardiac failure.

Aged↗