1,721,004 research outputs found
New hopes for dynamic cardiomyoplasty from use of Doppler flow wire in evaluation of demand stimulation
No full textJ Cardiovasc Surg (Torino). 2002 Feb;43(1):67-70.
New hopes for dynamic cardiomyoplasty from use of Doppler flow wire in evaluation of demand stimulation.
Rigatelli GL, Carraro U, Barbiero M, Zanchetta M, Rigatelli G.
Source
Division of Cardiology, Interventional Cardiology LAB and Cardiomyoplasty Project Unit, Legnago General Hospital, Verona, Italy. [email protected]
Abstract
BACKGROUND:
There are no data regarding real cardiac assistance in demand dynamic cardiomyoplasty (DDCMP). A test of the use of Doppler flow wire is presented to demonstrate cardiac assistance in DDCMP.
METHODS:
Comparative study in hospitalized care. A peripheral Flex Doppler flow wire of 0.018 inch was advanced through a 4F introducer femoral arterial in seven DDCMP patients (age=57.1+/-6.2 years; NYHA= 1.4+/-0.5). A short period of 10 sec with stimulator off and a following period of 15 sec with clinical stimulation were recorded. We measured the maximum peak aortic flow velocity (MPAV) in all beats. Latissimus dorsi (LD) mechanogram was simultaneously recorded.
RESULTS:
Statistical analysis showed an increase not only in MPAV in assisted period versus rest, but also in assisted beats versus unassisted (8.42+/-6.98% and 7.55+/-3.07%).
CONCLUSIONS:
Intravascular Doppler proved real systolic assistance in DDCMP; in DDCMP systolic assistance is correlated to the LD wrap speed of contraction, suggesting that demand stimulation could be the most effective protocol in dynamic cardiomyoplasty.
PMID:
11803332
[PubMed - indexed for MEDLINE
Demand dynamic bio-girdling in heart failure: improved efficacy of dynamic cardiomyoplasty by LD contraction during aortic out-flow
No full textInt J Artif Organs. 2003 Mar;26(3):217-24.
Demand dynamic bio-girdling in heart failure: improved efficacy of dynamic cardiomyoplasty by LD contraction during aortic out-flow.
Carraro U, Rigatelli G, Rossini K, Barbiero M, Rigatelli G.
Source
Italian C.N.R. Institute of Neuroscience, Unit for Neuromuscular Biology and Physiopathology, Laboratory of Applied Myology, Department of Biomedical Sciences, Padua Medical School, University of Padova, Padova, Italy. [email protected]
Abstract
PURPOSE:
The value of dynamic cardiomyoplasty has been brought into question by the disappointing results produced by slow contraction-relaxation cycle and possibly degeneration of the latissimus dorsi muscle (LD) secondary to temporary tenotomy and chronic daily electrical stimulation. Objective of our study is to determine whether daily periods of rest introduced by demand stimulation in the continuous contraction protocol produce systolic assistance and improve clinical results.
METHODS:
Twelve dynamic cardiomyoplasty patients (mean age 58.2 +/- 5.8 years, M/F=11/1, sinus rhythm/atrial fibrillation=11/1) with dilated myocardiopathy were enrolled in an unrandomized trial of Demand Dynamic Heart Bio-Girdling in a public regional teaching hospital. Periods of LD inactivity, each lasting several hours, were introduced daily on a heart rate-based demand regime. To avoid full transformation of LD, fewer impulses per day were delivered, daily providing the LD with long periods of rest (Demand light stimulation). The contractile properties were measured by transcutaneous non-invasive LD tensiomyogram interrogation (LD tensiomyogram). Bio-Girdle activation was synchronized to heart beat by combining tensiomyogram and echocardiography. Clinical, echocardiographic and hemodynamic records, as well as aortic flow measurements by Doppler aortic flow wire were taken during the follow-up.
MAIN FINDINGS:
Mean duration of the demand stimulation follow-up was 40.2+13.8 months. At five years, "Demand stimulation" shows: 1) no operative death; 2) 83% actuarial survival; 3) highly significant 47.4% decrease of the NYHA class (from 3.17 +/- 0.38 to 1.67 +/- 0.77, p=0.0001); 4) 41.6% improvement of LVEF (from 22.6 +/- 4.38 to 32.0 +/- 7.0, p=0.001); 5) 7.5 +/- 3.0% increase in aortic flow velocity peak in assisted vs. unassisted beats, and 6) preservation of LD from slowness (TFF value 33 +/- 7.86 at follow-up versus 15.8 +/- 11.1 Hz just before switching from continuous to demand stimulation, p=0.0001) and muscle degenerative atrophy.
CONCLUSIONS:
In dynamic cardiomyoplasty the demand light stimulation maintains LD contraction properties over time, produces effective systolic assistance, and improves clinical results. Demand dynamic bio-girdling is a safe and effective treatment for end-stage heart failure in selected patients.
PMID:
12703888
[PubMed - indexed for MEDLINE
A review of the concept of circulatory bioassist focused on the "new" demand dynamic cardiomyoplasty: the renewal of dynamic cardiomyoplasty?
No full textAngiology. 2003 May-Jun;54(3):301-6.
A review of the concept of circulatory bioassist focused on the "new" demand dynamic cardiomyoplasty: the renewal of dynamic cardiomyoplasty?
Rigatelli G, Carraro U, Barbiero M, Riccardi R, Cobelli F, Gemelli M, Rigatelli G.
Source
Cardiomyoplasty Project Unit, Legnago General Hospital, Verona, Italy. [email protected]
Abstract
After the initial enthusiasm, the dynamic cardiomyoplasty lost its reputation owing to the poor long-term results, caused by the muscular degeneration subsequent to chronic continuous electrical stimulation of the latissimus dorsi. An activity-rest stimulation protocol that avoids full transformation of the skeletal muscle, maintaining muscular properties over time, has been successfully tried. This "demand" stimulation protocol showed in humans good results improving NYHA class, ejection fraction value, and survival. The discussion about the capability of this and a unique kind of cardiocirculatory bioassist is due to be reopened. In fact, heart transplant, percutaneous circulatory-supporting device, multisites stimulation therapy, and total artificial heart have some drawbacks, one of which is the economic cost. In developing countries the more economic demand dynamic cardiomyoplasty may still play a role.
PMID:
12785022
[PubMed - indexed for MEDLINE
Cardiocirculatory bio-assist: is it time to reconsider demand dynamic cardiomyoplasty? Review and future perspectives
No full textASAIO J. 2003 Jan-Feb;49(1):24-9.
Cardiocirculatory bio-assist: is it time to reconsider demand dynamic cardiomyoplasty? Review and future perspectives.
Rigatelli G, Barbiero M, Rigatelli G, Cotocni A, Riccardi R, Cobelli F, Carraro U.
Source
Cardiomyopathy Project Unit, Legnago General Hospital, Verona, Italy.
Abstract
In the last 15 years, dynamic cardiomyoplasty has remained an experimental procedure even after the enthusiastic short- and mid-term results, mainly because of the disappointing long-term outcome caused by muscular degeneration secondary to chronic continuous electrical stimulation of the latissimus dorsi. In Italy, a group of muscular pathologists, cardiologists, and cardiac surgeons conducted an experiment of an activity-rest stimulation protocol in humans that should avoid complete transformation of the skeletal muscle, maintaining its properties overtime. This "demand" stimulation protocol gave good results, improving New York Heart Association class, ejection fraction value, and survival. Even though dynamic cardiomyoplasty was excluded from the recent international guidelines for the management of heart failure, the discussion on the ability of this unique kind of cardiocirculatory bio-assistance is due to be reopened, thanks to the results of the new stimulation protocol. Heart transplantation, circulatory supporting devices, multisite stimulation therapy, and the total artificial heart are not always and in all countries the best solutions: the great economic cost, the numerous contraindications, the need for immunosuppression and antithrombotic therapy, and the troublesome follow up constitute important drawbacks. For patients in whom transplant surgery cannot be performed, as well as in developing countries, the nonprohibitively expensive demand dynamic cardiomyoplasty may still play a role.
PMID:
12558303
[PubMed - indexed for MEDLINE
Activity-rest stimulation protocol improves cardiac assistance in dynamic cardiomyoplasty
No full textEur J Cardiothorac Surg. 2002 Mar;21(3):478-82.
Activity-rest stimulation protocol improves cardiac assistance in dynamic cardiomyoplasty.
Rigatelli G, Carraro U, Barbiero M, Zanchetta M, Dimopoulos K, Cobelli F, Riccardi R, Rigatelli G.
Source
Department of Cardiology, Interventional Cardiology Lab and Cardiomyoplasty Project Unit, Legnago General Hospital, Verona, Italy. [email protected]
Abstract
OBJECTIVE:
No data have ever been published regarding cardiac assistance in demand dynamic cardiomyoplasty (DDCMP). We tested the efficacy of the Doppler flow wire in measuring beat-to-beat aortic flow velocity and evaluating cardiac assistance in demand cardiomyoplasty patients.
METHODS:
The technique was tested in seven patients (M/F=6/1; age=57.1+/-6.2 years; atrial fibrillation/sinus rhythm=1/6; NYHA=1.4+/-0.5). Measurements were done using a 0.018inch peripheral Doppler flow wire advanced through a 5F arterial femoral sheath. Three 1-min periods with the stimulator off and three 1-min periods with clinical stimulation were recorded. We measured peak aortic flow velocity in all beats. Latissimus dorsi (LD) mechanogram was simultaneously recorded.
RESULTS:
Comparison between pre-operative and follow-up data showed significantly higher values of tetanic fusion frequency (TFF) and ejection fraction at follow-up, whereas mean NYHA class was significantly lower. Statistical analysis showed an increase in aortic flow velocity not only in assisted versus rest period, but also in assisted versus unassisted beats (8.42+/-6.98% and 7.55+/-3.07%). A linear correlation was found between the increase in flow velocity and LD wrap TFF (r(2)=0.53).
CONCLUSIONS:
In DDCMP, systolic assistance is significant and correlated to LD speed of contraction; demand stimulation protocol maintains muscle properties and increases muscle performance.
PMID:
11888767
[PubMed - indexed for MEDLINE
Maintained benefits and improved survival of dynamic cardiomyoplasty by activity-rest stimulation: 5-year results of the Italian trial on "demand" dynamic cardiomyoplasty
No full textEur J Cardiothorac Surg. 2003 Jan;23(1):81-5.
Maintained benefits and improved survival of dynamic cardiomyoplasty by activity-rest stimulation: 5-year results of the Italian trial on "demand" dynamic cardiomyoplasty.
Rigatelli G, Barbiero M, Rigatelli G, Riccardi R, Cobelli F, Cotogni A, Bandello A, Carraro U.
Source
Cardiomyoplasty Project Unit, Legnago General Hospital, Via T. Speri 18, 37040 Legnago, Verona, Italy. [email protected]
Abstract
OBJECTIVE:
Latissimus dorsi (LD) muscular degeneration caused by continuous electrical stimulation has been the main cause of the poor results of dynamic cardiomyoplasty (DCMP) and its exclusion from the recent international guidelines on heart failure. To avoid full transformation of the LD and to improve results, a new stimulation protocol was developed; fewer impulses per day are delivered, providing the LD wrap with daily periods of rest ("demand" stimulation), based on a heart rate cut-off. The aim of this work is to report the results at 5 years of follow-up of the Italian Trial of Demand Dynamic Cardiomyoplasty and to discuss their impact on the destiny of this type of cardiac assistance.
METHODS:
Twelve patients with dilated myocardiopathy (M/F=11/1, mean age 58.2+/-5.8 years, sinus rhythm/atrial fibrillation=11/1) were submitted during the period 1993-1996 to DCMP and at different intervals to demand protocol. Clinical, echocardiographic, mechanographic and cardiac invasive assessments were scheduled before initiating the demand protocol and during the follow-up at 0, 6 and every 12 months.
RESULTS:
The mean duration of follow-up was 40.2+/-13.8 months (range 18-64). There were no perioperative deaths. The demand stimulation protocol showed a decrease in 5 years in New York Health Association (NYHA) class (3.17+/-0.38-1.67+/-0.77, P=0.0001), an improvement of left ventricular ejection fraction (22.6+/-4.38-32.0+/-7.0, P<0.001), a 5-year actuarial survival of 83.3% (one patient was switched to heart transplantation programme due to clinical worsening and another one died of massive pulmonary embolism).
CONCLUSIONS:
Demand DCMP maintains over time LD muscular properties, enhances clinical benefits and improves survival of DCMP, thus reopening the debate whether this type of treatment should be considered in patients with end-stage heart failure.
PMID:
12493509
[PubMed - indexed for MEDLINE
Demand Dynamic Cardiomyoplasty: Mechanograms prove incomplete transformation of the rested LD
No full textAnn Thorac Surg. 2000 Jul;70(1):67-73.
Demand dynamic cardiomyoplasty: mechanograms prove incomplete transformation of the rested latissimus dorsi.
Carraro U, Barbiero M, Docali G, Cotogni A, Rigatelli G, Casarotto D, Muneretto C.
Source
Department of Biomedical Sciences, and Institute of Cardiovascular Surgery, University of Padua, Italy. [email protected]
Abstract
BACKGROUND:
In dynamic cardiomyoplasty, standard stimulation produces high fatigue resistance but also undesirable dynamic characteristics of the latissimus dorsi (LD). Based on results of intermittent stimulation in animals we introduced demand stimulation, a lighter regimen of LD activity-rest stimulation, and the mechanogram, a noninvasive method to determine the contractile characteristics of LD wrap.
METHODS:
Surgery and standard stimulation was according to the technique of Carpentier and Chachques, demand stimulation and LD wrap mechanogram were as we previously described. The LD contraction is synchronized to heart systole by mechanogram and echocardiography, and extent of transformation by tetanic fusion frequency analysis. A total of 22 patients were studied to date. Data for the 8 subjects who attained 6-month follow-up are reported. Four of them were lightly stimulated from the conditioning period, whereas 4 others were converted to light and then demand stimulation after years of standard stimulation. Patients were followed up with respect to survival, functional class, hospital admission rate, medication used, cardiopulmonary exercise testing, and LD wrap mechanography.
RESULTS:
Latissimus dorsi wrap slowness reverses by the activity-rest regimen, even after years of standard stimulation (Tetanic fusion frequency of 11 +/- 2 Hz after standard stimulation vs 30 +/- 3 Hz after demand regimen, p < 0.0001). After demand dynamic cardiomyoplasty there are no deaths. Quality of life is substantially improved with significant reduction of heart failure symptoms (New York Heart Association class: preoperative 3.0 +/- 0.0, post-demand dynamic cardiomyoplasty 1.5 +/- 0.2, p < 0.0001). In the subgroup of patients lightly stimulated from LD conditioning, exercise capacity tends to increase over preoperative values more than 2 years after operation (VO2 max: preoperative 12.3 +/- 0.7 vs 16.6 +/- 1.7 post-demand dynamic cardiomyoplasty, p = 0.05).
CONCLUSIONS:
Demand stimulation and mechanography of the LD wrap are safe procedures that could offer long-term benefits of dynamic cardiomyoplasty to patients with pharmacologically intractable heart failure.
PMID:
10921684
[PubMed - indexed for MEDLINE
LQR Temperature Control in smart building via real-time weather forecasting
Full text linkIn this work we consider the problem of climate control within a smart building instrumented with multiple temperature sensors and controllable HVACs. The main contri-bution is to use real-time weather forecasting readily available via internet connection to obtain real-time information about external temperature and solar insulation to reject external disturbances and anticipate temperature changes. The control system is based on MIMO LQR control with a reduced order observer and integral control applied to a model of the building dynamics obtained from construction data. The proposed architecture shows substantial improvements in numerical simu-lations as compared to PID-based standard controllers in terms of improved comfort, while being computationally simpler than more advanced solutions such as MPC or AI-based control
New advances in dynamic cardiomyoplasty: Doppler flow wire shows improved cardiac assistance in demand protocol
No full textASAIO J. 2002 Jan-Feb;48(1):119-23.
New advances in dynamic cardiomyoplasty: Doppler flow wire shows improved cardiac assistance in demand protocol.
Rigatelli G, Carraro U, Barbiero M, Zanchetta M, Pedon L, Dimopoulos K, Rigatelli G, Maiolino P, Cobelli F, Riccardi R, Volta SD.
Source
Department of Cardiology, Legnago General Hospital, Verona, Italy.
Abstract
No data have been published on real cardiac assistance with demand dynamic cardiomyoplasty. We tested the utility of a Doppler flow wire in measuring beat by beat aortic flow velocity and evaluating cardiac assistance in demand cardiomyoplasty patients. The technique was tested in seven patients (M/W = 6/1; age, 57.1+/-6.2 years; atrial fibrillation/ sinus rhythm = 1/6; New York Heart Association [NYHA] classification = 1.4+/-0.5). Measurements were done using a 0.018 inch peripheral Doppler flow wire advanced through a 5 French arterial femoral sheath. Three 1 minute periods with the stimulator off, and three 1 minute periods with clinical stimulation were recorded. We measured peak aortic flow velocity in all beats. Latissimus dorsi mechanogram was simultaneously recorded. Comparison between preoperative and follow-up data showed significantly higher values of tetanic fusion frequency and ejection fraction at follow-up, whereas mean NYHA class was significantly lower. Statistical analysis showed an increase in aortic flow velocity not only in the assisted versus rest period, but also in assisted versus unassisted beats (8.42+/-6.98% and 7.55+/-3.07%). A linear correlation was found between increase in flow velocity and latissimus dorsi wrap tetanic fusion frequency (r2 = 0.53). In demand dynamic cardiomyoplasty, systolic assistance is significant and correlated to the latissimus dorsi speed of contraction; a demand stimulation protocol maintains muscle properties and increases muscle performance.
PMID:
11814090
[PubMed - indexed for MEDLINE
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