PubMed Health⌕ Search

Biomedical subjects

P Cartier

Publications and source records attributed to P Cartier.

At least 19 recordsLinked to original sources
PubMed2001

A single center experience with the freestyle bioprosthesis: midterm results at the Québec Heart Institute.

Stentless bioprostheses show excellent early hemodynamic performance. However, longevity still remains unknown. This study reports midterm follow-up in 419 patients in which a Freestyle bioprosthesis (Medtronic Heart Valves, Minneapolis, MN) was inserted between January 1993 and January 2000 at the Quebec Heart Institute (Ste-Foy, Québec, Canada). Mean age at implantation was 68.0 +/- 8.2 years. Implantation was subcoronary in 81.9% of the patients, as a root replacement in 16.5%, and as a root inclusion in 1.7%. Mortality at 30 days was 6.2% for the whole cohort (2.8% for isolated subcoronary aortic valve replacement). Female gender, root implantation, valve sizes 19 to 21 mm, previous surgery, a history of stroke and diabetes were identified as predictors of 30-day mortality. Actuarial freedom from all death causes was 81.5% at 7 years; freedom from valve-related deaths 97.0%, and freedom from cardiac deaths 92.7%. Freedom from thromboembolic events was 86.1% at 7 years (55.1% of events were < 30 days). Freedom from endocarditis and hemorrhagic complications were respectively 98.5% and 95.6% at 7 years. Six patients required reoperations for valve explantation: 2 for endocarditis, 2 for structural dysfunction, and 2 for nonstructural dysfunction. Incidence of moderate or severe valve insufficiency at annual echocardiographic follow-up was: discharge: 0.6%; year 1: 0.7%; year 2: 1.3%; year 3: 3.3%; year 4: 3.7%; year 5: 2.6%; year 6: 0%. At 6 years after implantation, mean transvalvular gradient and effective valve orifice area were comparable to the year 1 values. This single center experience with the Medtronic Freestyle prosthesis shows preserved hemodynamic performance and low valve-related complications at midterm.

Actuarial Analysis↗
PubMed2000

Midterm echocardiographic follow-up after Ross operation.

BACKGROUND: The pulmonary autograft (Ross) operation is an attractive treatment for aortic valve disease, but hemodynamic follow-up is not well defined. METHODS AND RESULTS: One hundred thirty-two consecutive patients (62% male, mean age 40+/-11 years) were followed up to 5 years after the Ross operation. Echocardiography was performed early (within 30 days), 3 to 6 months, and yearly after surgery. The valve effective orifice area (EOA) and mean transvalvular gradient of both aortic and pulmonary valves were measured, and transvalvular regurgitation was assessed by using color Doppler echocardiography. EOA was indexed for body surface area. The hemodynamic performance was excellent for both the aortic and pulmonary valves early after surgery (gradient, 3+/-4 and 3+/-4 mm Hg, respectively). It remained stable thereafter for the aortic valve, whereas there was a significant deterioration of the EOA (-0. 74+/-0.82 cm(2)) and gradient (+6+/-8 mm Hg) for the pulmonary valve, which occurred mostly during the first 6 months after surgery. This hemodynamic deterioration resulted in suboptimal (defined as an EOA index <0.85 cm(2)/m(2)) hemodynamics in 19.3% of the patients, to the extent that 3 (2%) of the 132 patients eventually had to be subjected to further surgery for severe pulmonary valve stenosis. CONCLUSIONS: The pulmonary autograft provides continued excellent hemodynamics in the aortic position, whereas moderately high gradients can be found across the pulmonary homograft in some patients. Further studies are necessary to identify the factors responsible for the deterioration of the hemodynamic performance of the homograft in the pulmonary position and to determine its impact on right ventricular function and clinical status.

Adult↗
PubMed2000

Hemodynamic performance during maximum exercise in adult patients with the ross operation and comparison with normal controls and patients with aortic bioprostheses.

This study examines the resting and exercise hemodynamic performance of the pulmonary autografts in the aortic position as well as of the homografts used for right ventricular outflow reconstruction in patients undergoing the Ross operation. Previous studies have reported excellent resting hemodynamics in patients who underwent aortic valve replacement with a pulmonary autograft. However, there are very few studies of their hemodynamic performance during exercise. Twenty adult subjects who underwent the Ross operation and 12 normal control subjects were submitted to maximum romp bicycle exercise. The valve effective orifice areas and transvalvular gradients of both aortic (autograft) and pulmonary (homograft) valves were measured at rest and at peak of maximum exercise using Doppler echocardiography. Valve areas were indexed for body surface area. The hemodynamics of the aortic valve were very similar in Ross subjects and in control subjects at rest and during exercise. However, the indexed valve area of the pulmonary valve at rest was significantly (p < 0.001) lower in the Ross subjects (1.10 +/- 0.46 cm2/ m2) than in the control subjects (1.95 +/- 0.41 cm2/m2), resulting in higher (p = 0.004) mean gradients at rest (Ross: 9 +/- 7 mm Hg vs control: 2 +/- 1 mm Hg) and at peak exercise (Ross: 21 +/- 14 mm Hg vs control: 7 +/- 2 mm Hg). The pulmonary autograft provided excellent hemodynamics in the aortic position either at rest or during maximum exercise, whereas moderately high gradients were found during exercise across the homograft implanted in the pulmonary valve position. Future improvement of the Ross procedure should be oriented toward the search of new methods to prevent the deterioration of the homografts.

Adult↗
PubMed2000

Effect of hemoglobin levels in hemodialysis patients with asymptomatic cardiomyopathy.

BACKGROUND: Hemoglobin levels below 10 g/dL lead to left ventricular (LV) hypertrophy, LV dilation, a lower quality of life, higher cardiac morbidity, and a higher mortality rate in end-stage renal disease. The benefits and risks of normalizing hemoglobin levels in hemodialysis patients without symptomatic cardiac disease are unknown. METHODS: One hundred forty-six hemodialysis patients with either concentric LV hypertrophy or LV dilation were randomly assigned to receive doses of epoetin alpha designed to achieve hemoglobin levels of 10 or 13.5 g/dL. The study duration was 48 weeks. The primary outcomes were the change in LV mass index in those with concentric LV hypertrophy and the change in cavity volume index in those with LV dilation. RESULTS: In patients with concentric LV hypertrophy, the changes in LV mass index were similar in the normal and low target hemoglobin groups. The changes in cavity volume index were similar in both targets in the LV dilation group. Treatment-received analysis of the concentric LV hypertrophy group showed no correlation between the change in mass index and a correlation between the change in LV volume index and mean hemoglobin level achieved (8 mL/m2 per 1 g/dL hemoglobin decrement, P = 0.009). Mean hemoglobin levels and the changes in LV mass and cavity volume index were not correlated in patients with LV dilation. Normalization of hemoglobin led to improvements in fatigue (P = 0.009), depression (P = 0.02), and relationships (P = 0.004). CONCLUSIONS: Normalization of hemoglobin does not lead to regression of established concentric LV hypertrophy or LV dilation. It may, however, prevent the development of LV dilation, and it leads to improved quality of life.

Adult↗
PubMed2000

Outpatient CAPD catheter salvage for persistent exit-site/tunnel infection.

BACKGROUND: Partial replantation (i.e. replacement of the extraperitoneal portion of the catheter with creation of a new subcutaneous tunnel) has been suggested to avoid catheter removal in patients with persistent exit-site/tunnel infection (ESTI). However, published experience with this technique is limited. METHODS: Partial replantation was performed on an outpatient basis under local anesthesia for seven patients with persistent ESTI of >3 months duration. All patients resumed CAPD immediately following surgery. RESULTS: One patient had dialysate leakage less than 1 week after surgery that required catheter removal. The other patients had no complications and mean catheter survival following surgery was 7. 7 months (range 3.5-13 months). There was no recurrence of ESTI after surgery, although two patients presented with exit-site infection unrelated to the initial episode (i.e. different organism, long latency). Three other patients presented with episodes of peritonitis unrelated to surgery (i.e. delay >1 month) or ESTI (i.e. different organism). CONCLUSIONS: Partial replantation allows significant prolongation of catheter survival without major complications or interruption of CAPD. This novel procedure appears to be an appropriate alternative to catheter removal for the management of persistent ESTI. However, further studies are needed to prospectively compare partial replantation with catheter removal.

Aged↗
PubMed1999

Hemodynamic and physical performance during maximal exercise in patients with an aortic bioprosthetic valve: comparison of stentless versus stented bioprostheses.

OBJECTIVES: The objective of this study was to compare stentless bioprostheses with stented bioprostheses with regard to their hemodynamic behavior during exercise. BACKGROUND: Stentless aortic bioprostheses have better hemodynamic performances at rest than stented bioprostheses, but very few comparisons were performed during exercise. METHODS: Thirty-eight patients with normally functioning stentless (n = 19) or stented (n = 19) bioprostheses were submitted to a maximal ramp upright bicycle exercise test. Valve effective orifice area and mean transvalvular pressure gradient at rest and during peak exercise were successfully measured using Doppler echocardiography in 30 of the 38 patients. RESULTS: At peak exercise, the mean gradient increased significantly less in stentless than in stented bioprostheses (+5 +/- 3 vs. +12 +/- 8 mm Hg; p = 0.002) despite similar increases in mean flow rates (+137 +/- 58 vs. +125 +/- 65 ml/s; p = 0.58); valve area also increased but with no significant difference between groups. Despite this hemodynamic difference, exercise capacity was not significantly different, but left ventricular (LV) mass and function were closer to normal in stentless bioprostheses. Overall, there was a strong inverse relation between the mean gradient during peak exercise and the indexed valve area at rest (r = 0.90). CONCLUSIONS: Hemodynamics during exercise are better in stentless than stented bioprostheses due to the larger resting indexed valve area of stentless bioprostheses. This is associated with beneficial effects with regard to LV mass and function. The relation found between the resting indexed valve area and the gradient during exercise can be used to project the hemodynamic behavior of these bioprostheses at the time of operation. It should thus be useful to select the optimal prosthesis given the patient's body surface area and level of physical activity.

Bioprosthesis↗
PubMed1999

Thoracoscopic cervicodorsal sympathectomy with diathermy.

This study reports our experience of using thoracoscopic cervicodorsal sympathectomy with diathermy. From December 1994 to September 1998, we performed 53 thoracoscopic sympathectomies in 35 patients. There were 15 men and 20 women, ages 18 to 61 years. Ten surgeries were performed on the right side, 7 were the left, and 18 were bilateral. Indications for surgery were causalgia/reflex sympathetic dystrophy in 8 patients, Raynaud's/vasculitis in 6, intractable Raynaud's disease in 4, and hyperhydrosis in 17 (bilateral procedure). Operating time ranged from 10 to 50 min for unilateral procedures and from 45 to 80 min for bilateral procedures. Patients stayed in the hospital 1 to 4 days. From favorable immediate and follow-up results we conclude that thoracoscopic cervicodorsal sympathectomy using diathermy is feasible, safe, and effective.

Adolescent↗
PubMed1999

Changes in left ventricular mass and function after aortic valve replacement: a comparison between stentless and stented bioprosthetic valves.

The objective of this study was to compare stentless bioprostheses with stented bioprostheses with regard to the postoperative changes in left ventricular (LV) mass and function. Forty patients with aortic stenosis undergoing valve replacement with a stentless (20 patients) or a stented (20 patients) bioprosthesis were evaluated early (baseline), 1 year, and 2 years after operation. Left ventricular mass index was calculated with the corrected American Society of Echocardiography formula. The relative changes between end-diastole and end-systole in LV mid-wall radius, length, and volume (ejection fraction) were determined with a previously validated model for dynamic geometry of the left ventricle. Overall, a significant decrease was found in LV mass index (from 155 +/- 30 to 112 +/- 23 g/m(2); P <.001) and a significant increase in longitudinal shortening (from 0.12 +/- 0.11 to 0.22 +/- 0.08; P <. 001), and ejection fractions (from 0.67 +/- 0.11 to 0.71 +/- 0.10; P =.017). No significant change was found in the mid-wall radius shortening fraction. Two years after surgery, the extent of LV mass regression was greater in stentless bioprostheses (-51 +/- 18 vs -35 +/- 17 g/m(2); P =.01), though the average mass index was similar in both groups (114 +/- 26 vs 110 +/- 20 g/m(2)). Also at 2 years, the longitudinal shortening fraction was greater in patients with a stentless bioprosthesis (0.25 +/- 0.07 vs 0.18 +/- 0.08; P =.03). In conclusion, this study suggests that the superior hemodynamic performance of stentless bioprostheses may have some benefits with regard to LV mass regression and function after aortic valve replacement. The significance of these benefits in terms of prognosis remains to be determined.

Aged↗
PubMed1999

Metabolic and antihypertensive effects of nebivolol and atenolol in normometabolic patients with mild-to-moderate hypertension.

This was a double-blind, randomized, two-center, active-controlled, prospective, parallel study designed to evaluate the effects of nebivolol at daily doses of 5 mg on lipid and carbohydrate metabolism and on blood pressure in comparison with atenolol at daily doses of 50 mg. Normometabolic subjects with mild-to-moderate essential hypertension were recruited for this study, which included a 4-week, single-blind placebo washout phase and a 12-week double-blind treatment phase. After 12 weeks of treatment, both drugs demonstrated a significant decrease from baseline in high-density lipoprotein (HDL) apolipoprotein A-I (HDL-apoA-I) (nebivolol, P <.02; atenolol, P <.05). A significant reduction in HDL cholesterol (HDL-C) from baseline was also observed with nebivolol (P <.05). There were no significant differences between the drugs for these parameters, and the ratio low-density lipoprotein cholesterol (LDL-C)-to-HDL-C did not change significantly after 12 weeks of active treatment with nebivolol or atenolol. There were no significant changes in total cholesterol, HDL (2) -C, HDL (3) -C, LDL-C, very-low-density lipoprotein cholesterol (VLDL-C), total triglycerides, HDL-triglycerides (TG), LDL-TG, VLDL-TG, total apoB, LDL-B, VLDL-B (including the ratio LDL-C-to-LDL-apoB), or Lp(a) during treatment with both drugs. No significant differences in plasma apoA-I and apoC-III as well as in apoA-I-, C-III-containing lipoprotein particles (including the apoC-III ratio) were observed between the drugs, neither before nor after each active treatment. There were no significant differences between the drugs or within each treatment group in plasma glucose, insulin, or C-peptide concentrations after a 2-hour oral glucose tolerance test. Mean clinic trough sitting systolic blood pressure (SBP)/diastolic blood pressure (DBP) significantly decreased from 150/98 mm Hg at baseline to 141/90 mm Hg at termination for nebivolol and from 160/99 mm Hg at baseline to 145/88 mm Hg at termination for atenolol. No significant between-treatment differences were observed for the mean clinic trough sitting SBP/DBP. Both drugs significantly increased the atrial natriuretic factor (ANF) N-terminal plasma levels, whereas no changes were observed in ANF C-terminal plasma concentrations. A significant decrease (P <. 05) in the plasma adrenocorticotropic hormone levels was observed after administration of both drugs. A significant decrease (P <.05) in plasma cortisol levels was observed only after atenolol treatment. The incidence of adverse events reported during nebivolol treatment was comparable to that observed during atenolol treatment. Heart rate was significantly reduced by both drugs. There were no significant changes in hematology, biochemistry, or urinalysis studies. Neither nebivolol nor atenolol adversely affected lipid or carbohydrate metabolism in normometabolic hypertensive patients. Both treatments demonstrated adequate and similar antihypertensive effects and were well tolerated.

Adrenocorticotropic Hormone↗
PubMed1999

The effect of prosthetic valve type on survival after aortic valve surgery.

A number of recent reports have suggested that valve design has an influence on long-term survival after aortic valve replacement (AVR). The present study examines the clinical results of two large multicenter trials of the Hancock II stented and Medtronic Freestyle stentless bioprosthetic valves. In all cases a subcoronary implant technique was used. All patients were operated on between 1991 and 1994, and all patients were monitored for 5 years. The 5-year actuarial survival rate was 86% for Freestyle and 77% for Hancock patients (P<.05). Late mortality occurred in 40 Freestyle patients (8.8%) compared with 36 Hancock II patients (16.1%, P = .0074). Cox's proportional hazard models were used to identify independent predictors of 5-year survival for the two groups. Hazard ratio (HR) and P value are presented in parentheses. The final analysis included the interactive variable valve*age. The resultant model indicates that the interaction of age and valve type has a significant effect on outcome. In patients < or =60 years of age at the time of operation, AVR with a Hancock II valves was associated with nearly a fivefold risk of death compared with patients of the same age who received a Freestyle valve (HR = 4.97, P = .0004). However, this survival advantage decreased by 50% with each decade thereafter (valve*age interaction HR = 0.50, P = .0027). Our data indicate that AVR with a stentless valve confers a survival advantage to the patient. The probability of dying within 5 years of surgery is 50% greater in patients who received a Hancock II versus a Freestyle valve (HR = 1.50, P = .0442). However, this survival advantage is most prominent in younger patients (<60 years of age) where the probability of death is fivefold greater with Hancock than Freestyle valves. With advancing age the benefits of stentless valves are diminished.

Actuarial Analysis↗
PubMed1999

Aortic valve replacement with Medtronic Freestyle bioprosthesis: 5-year results.

The Medtronic Freestyle aortic root bioprosthesis has been implanted in patients since August 1992. This study reviews clinical and echocardiographic results at midterm (5 years) after implantation. The Freestyle bioprosthesis was implanted in 1,100 patients in a 21-center Food and Drug Administration clinical trial from August 1992 to October 1998. The device was implanted (1) as a subcoronary valve replacement, (2) as a complete aortic root replacement (full-root), or (3) as a root inclusion. Patients were followed annually by clinical examination and echocardiography. There were 47 deaths early after operation (7.1%). There were 2,478 patient-years of follow-up during which there were 99 deaths or 4.0/pt.-yr. Before implantation, 73% of patients were in New York Heart Association functional class III or IV. After operation, 95% were in class I or II. Transvalvular gradient 4 years after operation was low (7.5+/-5.3 mm Hg) for all valve sizes (subcoronary implant). Small valves (19 and 21 mm) had mean gradients (10.2+/-3.0, 9.1+/-4.4 mm Hg). There was no or mild valve insufficiency in 98% of patients. Actuarial analysis at 5 years showed the rate for freedom from thromboembolism of 86% in subcoronary implant and 93% in full root replacement. Freedom from endocarditis was 98%. Freedom from reoperation for explant of the valve highest in patients having full root replacement (98%) and lower with root inclusion (94%). There were 20 bioprostheses explanted; 10 for endocarditis, 8 for technical reasons, and 2 for structural deterioration. The Medtronic Freestyle bioprosthesis (1) has excellent hemodynamic performance, (2) techniques for insertion that result in a competent valve, (3) low rates of thromboembolism and endocarditis, and (4) a rare rate of structural deterioration at 5 years.

Aged↗
PubMed1999

Factors affecting left ventricular mass regression after aortic valve replacement with stentless valves.

The hemodynamic benefits of using stentless valves for replacement of the human aortic valve have become more well known. These devices are associated with significant decrease in left ventricular (LV) mass and LV remodeling in the early postoperative period. However, no large study has examined patient-related and valve-related factors that may contribute to this phenomenon. This study examined 1,103 patients who underwent aortic valve replacement (AVR) with a stentless porcine valve (Freestyle = 840, SPV = 263). In all cases, a subcoronary implant technique was used. Valve performance was assessed by serial echocardiograms. At 3 years' post-AVR, mean gradient was 6.3+/-5.0 mm Hg, and effective orifice area (EOA) was 2.0+/-0.7 cm2. Indexed EOA was 1.2+/-0.4 cm2/m2. There was an association between indexed EOA and the extent of LV mass regression. At 3 years after surgery, LV mass index (LVMI) was reduced to 76.3% to 78.7% of baseline in patients whose indexed EOA was >0.8 cm2/m2. In contrast, for patients with an indexed EOA that was <0.8 cm2/m2, LVMI at 3 years was 95.5% of baseline (P = .0001). Multiple linear regression models were used to identify parameters that predicted the 3-year LVMI. Baseline LVMI (P<.0001), prior myocardial infarction (P = .0009), male gender (P = .0036), and carotid stenosis (P = .022) were independent predictors of LV mass regression. Valve type, valve size, preoperative New York Heart Association class symptoms, coronary disease, prior bypass surgery, chronic obstructive pulmonary disease, or underlying valve pathology had no effect on LV mass regression. Data indicate that baseline LVMI and patient-prosthetic mismatch have major effects on the extent of LV mass regression post-AVR. Long-term hemodynamic benefits of AVR can be optimized by proper selection of the prosthesis so as to avoid mismatch. Furthermore, because the baseline LVMI affects the extent of regression post-AVR, early intervention may result in more complete resolution of LV mass postoperatively, which may have important prognostic implications.

Aged↗
PubMed1998

Impact of prosthesis-patient mismatch on hemodynamic and symptomatic status, morbidity and mortality after aortic valve replacement with a bioprosthetic heart valve.

BACKGROUND AND AIMS OF THE STUDY: Previous studies have shown that the effective orifice area of an aortic prosthetic valve may be too small in relation to the patient's body surface area, resulting in abnormally high gradients. The consequences of this condition, termed prosthesis-patient mismatch, have not been fully studied. The study objective was to determine if the condition has a detrimental effect on symptomatic and hemodynamic status, morbidity and mortality of patients undergoing aortic valve replacement. METHODS: A cohort of 392 patients was prospectively followed for up to seven years after implantation of a Medtronic Intact bioprosthesis. Doppler echocardiography was performed annually in 72 patients. Based on previous studies, presence of mismatch was defined as an indexed valve area < or = 0.85 cm2/m2. RESULTS: Mismatch was associated with less postoperative improvement of NYHA functional class (p < 0.009) independently of other predictors, such as age and preoperative functional class, but had no significant impact on patient survival (mismatch: 75 +/- 4%, no mismatch: 79 +/- 3%; p = 0.59) and valve-related morbidity up to seven years. Cardiac index was similar in patients with and without mismatch up to three years after operation but decreased significantly thereafter only in patients with mismatch (-0.54 +/- 0.32 versus -0.17 +/- 0.49 l/min/m2; p = 0.04). Likewise, the mean transprosthetic gradient, which was higher at one year after operation in patients with mismatch (22 +/- 8 versus 15 +/- 7 mmHg), increased significantly (+6 +/- 6 versus +1 +/- 1 mmHg; p = 0.008) only in this group during follow up. CONCLUSIONS: Patients with mismatch have less symptomatic improvement and worse hemodynamics that continue to deteriorate with time. However, medium-term prognosis (up to seven years) is relatively good. Further studies are necessary to determine the longer-term effects of mismatch on morbidity and mortality.

Aged↗
PubMed1998

Different effects of nifedipine and amlodipine on circulating catecholamine levels in essential hypertensive patients.

OBJECTIVE: To compare the acute and chronic effects of nifedipine retard (NPA), nifedipine gastrointestinal therapeutic system (NGITS) and amlodipine at trough and peak plasma concentrations of drug on blood pressure and heart rate, and on plasma norepinephrine and epinephrine levels in patients with mild-to-moderate hypertension (diastolic blood pressure 95-115 mmHg). DESIGN AND METHODS: After 3-4 weeks' placebo treatment, patients of both sexes were randomly allocated to be administered 10 or 20 mg NPA twice a day, 30 or 60 mg NGITS once a day, and 5 or 10 mg amlodipine once a day for 6 weeks. Initially, for the first 2 weeks, the lowest dose of each drug was used, but higher doses were administered after 2 weeks if sitting diastolic blood pressure was > 90 mmHg. Patients were evaluated after administration of the first dose and after 6 weeks' therapy in a hospital setting. Blood samples were taken for high-performance liquid chromatography measurement of catecholamine and drug levels at various intervals for a period covering trough to peak drug level ranges. RESULTS: Administration of all three drugs reduced clinic blood pressure to the same level after 6 weeks' therapy, but heart rate was increased slightly only with amlodipine (P < 0.05). Administration of NPA reduced blood pressure more abruptly whereas administrations of NGITS and amlodipine induced smoother falls after acute and chronic treatments: a significant increase in heart rate was observed with amlodipine after chronic treatment. Both acute and chronic treatments with NPA (n = 19) increased norepinephrine levels (P < 0.01) transiently (2-4 h). In contrast, administration of NGITS (n = 22) did not increase norepinephrine levels and even induced a slight but significant decrease in norepinephrine levels 5-6 h after chronic treatments. Although administration of amlodipine (n = 22) did not increase norepinephrine levels transiently either after acute or after chronic administration, it did induce a sustained rise in basal norepinephrine levels by more than 50% after chronic therapy (P < 0.01). Plasma epinephrine levels were not increased by any of the treatments and even a slight decrease was observed 4 h after administration of a dose following chronic treatments with NGITS and amlodipine (P < 0.05). CONCLUSIONS: The transient increase in norepinephrine levels observed with NPA and the sustained increases in norepinephrine levels observed after chronic treatment with amlodipine suggest that sympathetic activation occurs with those two drugs. The lack of increase in norepinephrine levels after administration of NGITS suggests that this formulation does not activate the sympathetic system. The lowering of epinephrine levels after administrations of NGITS and amlodipine suggests that inhibition of release of epinephrine by the adrenal medulla occurs with longer-acting dihydropyridine formulations.

Adult↗
PubMed1998

Different effects of nifedipine and amlodipine on circulating catecholamine levels in essential hypertensive patients.

OBJECTIVE: To compare the acute and chronic effects of nifedipine retard (NPA), nifedipine gastrointestinal therapeutic system (NGITS) and amlodipine at trough and peak plasma concentrations of drug on blood pressure and heart rate, and on plasma norepinephrine and epinephrine levels in patients with mild-to-moderate hypertension (diastolic blood pressure 95-115 mmHg). DESIGN AND METHODS: After 3-4 weeks' placebo treatment, patients of both sexes were randomly allocated to be administered 10 or 20 mg NPA twice a day, 30 or 60 mg NGITS once a day, and 5 or 10 mg amlodipine once a day for 6 weeks. Initially, for the first 2 weeks, the lowest dose of each drug was used, but higher doses were administered after 2 weeks if sitting diastolic blood pressure was > 90 mmHg. Patients were evaluated after administration of the first dose and after 6 weeks' therapy in a hospital setting. Blood samples were taken for high-performance liquid chromatography measurement of catecholamine and drug levels at various intervals for a period covering trough to peak drug level ranges. RESULTS: Administration of all three drugs reduced clinic blood pressure to the same level after 6 weeks' therapy, but heart rate was increased slightly only with amlodipine (P < 0.05). Administration of NPA reduced blood pressure more abruptly whereas administrations of NGITS and amlodipine induced smoother falls after acute and chronic treatments: a significant increase in heart rate was observed with amlodipine after chronic treatment. Both acute and chronic treatments with NPA (n = 19) increased norepinephrine levels (P < 0.01) transiently (2-4 h). In contrast, administration of NGITS (n = 22) did not increase norepinephrine levels and even induced a slight but significant decrease in norepinephrine levels 5-6 h after chronic treatments. Although administration of amlodipine (n = 22) did not increase norepinephrine levels transiently either after acute or after chronic administration, it did induce a sustained rise in basal norepinephrine levels by more than 50% after chronic therapy (P < 0.01). Plasma epinephrine levels were not increased by any of the treatments and even a slight decrease was observed 4 h after administration of a dose following chronic treatments with NGITS and amlodipine (P < 0.05). CONCLUSIONS: The transient increase in norepinephrine levels observed with NPA and the sustained increases in norepinephrine levels observed after chronic treatment with amlodipine suggest that sympathetic activation occurs with those two drugs. The lack of increase in norepinephrine levels after administration of NGITS suggests that this formulation does not activate the sympathetic system. The lowering of epinephrine levels after administrations of NGITS and amlodipine suggests that inhibition of release of epinephrine by the adrenal medulla occurs with longer-acting dihydropyridine formulations.

Adult↗
PubMed1998

Rapidly evolving constrictive tuberculous pericarditis: case presentation and review of the literature.

A 69-year-old male presented with a diagnosis of idiopathic pericarditis, first treated with prednisone for a few weeks with resolution of the symptoms. A few days after stopping the medication, he presented with malaise, cough and signs of pericardial constriction confirmed by echocardiography. He was diagnosed with pulmonary tuberculosis with pericardial involvement and treated accordingly. Pericardiectomy was performed after a few days of treatment because the symptoms related to constriction progressed. The procedure was successful, and the patient was completely asymptomatic after 10 months. The removed pericardium stained positive for acid-fast bacilli.

Aged↗