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1.
Transplant Proc ; 51(6): 1838-1844, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31256870

RESUMEN

OBJECTIVE: The aim of this study was to evaluate the effects of using thromboembolic deterrent (TED) stockings and intermittent pneumatic compression (IPC) vs a muscle pump activator (MPA) device on limb edema and patient satisfaction after transplant. METHODS: In this single-center randomized controlled trial, 118 patients were randomly assigned to wear TED + IPC (n = 64) or the MPA device (n = 54) from postoperative days 1 to 6. We measured patients' weight and lower leg and thigh circumferences daily. Ultrasonography of the allograft and lower limbs was carried out on postoperative days 1 and 5 to assess resistive index in the transplanted kidney and flow in the femoral vein. We monitored urine output and serum creatinine level. RESULTS: We observed a significant increase in calf and thigh circumference from baseline in the TED + IPC group but not in the MPA group (2.3 [SD, 1] cm vs 0.25 [SD, 0.8] cm, respectively, P < .002). Ultrasonography showed higher femoral vein velocities in the MPA group than the TED + IPC group (0.5 [SD, 0.2] cm, P < .001). The mean total urine output in 6 days was higher in the MPA group than the TED + IPC group (P = .05), which corresponded to large change in TED + IPC weight of 6.2 kg vs 2.1 kg in the MPA group (P = .04). Patients were more satisfied with the use of the MPA device than TED + IPC. No major complications were encountered in either group. CONCLUSIONS: This is the first study to show that the use of an MPA device in the immediate postoperative period following kidney transplant leads to decreased lower limb edema and increased total urine output. Patients were more satisfied with the use of the MPA device than TED + IPC.


Asunto(s)
Circulación Asistida/instrumentación , Edema/terapia , Terapia por Estimulación Eléctrica/instrumentación , Trasplante de Riñón/efectos adversos , Complicaciones Posoperatorias/terapia , Adulto , Anciano , Circulación Asistida/métodos , Velocidad del Flujo Sanguíneo/fisiología , Edema/etiología , Edema/fisiopatología , Terapia por Estimulación Eléctrica/métodos , Femenino , Vena Femoral , Hemodinámica/fisiología , Humanos , Extremidad Inferior/irrigación sanguínea , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/fisiopatología , Periodo Posoperatorio , Medias de Compresión , Resultado del Tratamiento
2.
Int Wound J ; 16(1): 266-274, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30460740

RESUMEN

Chronic non-healing wounds are a burden in the Long-Term Care (LTC) sector, increasing costs, morbidity, and mortality and causing pain and suffering. The objective of this LTC Innovation pilot was to test the value of a promising new neuromuscular stimulation device in elevating the experience and satisfaction of the residents, engaging and empowering the nursing staff, and improving healing and/or reducing costs. Small, wireless, and worn at the knee, this muscle pump activator is self-contained, wearable, and battery-powered to increase lower-leg blood circulation (up to 60% of that achieved by walking). It has no wires, weighs just 10 g, and is easy to use. Nurses in four LTC homes identified residents with non-healing lower leg wounds. Consent was obtained, and on-site training was delivered. Eleven residents were recruited. Only seven met the inclusion criteria for venous/mixed or diabetic foot ulcers. Of the seven who met the criteria and were adherent with best practices and the muscle pump activator, four healed 100%, and one healed 90%. Two patients with other aetiologies, who were also adherent, healed. All adherent residents had an average weekly decrease in wound size of 9.75% and were extremely happy with the results. Three residents who were non-adherent had a 9.25% increase in wound size per week. One patient with diabetic foot ulcers developed skin changes at the end of life and passed away. Nursing staff and cognisant residents can easily adjust the pulse of muscle pump activator, and application and removal are simple. Most residents feel engaged with the therapy "because they feel it working". The LTC corporation feels that it is a great adjunctive solution for many types of lower-leg wounds (venous, mixed, diabetic, pressure) in addition to best practices in the LTC and Retirement home sectors.


Asunto(s)
Circulación Asistida/instrumentación , Velocidad del Flujo Sanguíneo/fisiología , Enfermedad Crónica/terapia , Pie Diabético/terapia , Terapia por Estimulación Eléctrica/instrumentación , Úlcera Varicosa/terapia , Cicatrización de Heridas/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Circulación Asistida/métodos , Terapia por Estimulación Eléctrica/métodos , Femenino , Hogares para Ancianos , Humanos , Cuidados a Largo Plazo/métodos , Masculino , Persona de Mediana Edad , Casas de Salud , Proyectos Piloto
3.
J Cardiopulm Rehabil Prev ; 34(4): 233-40, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24531204

RESUMEN

Because a limited number of patients receive heart transplantation, alternative therapies, such as left ventricular assist device (LVAD) therapy, have emerged. Published studies have shown that LVAD implantation, by itself, improves exercise tolerance to the point where it is comparable to those with mild heart failure. The improvement in exercise capacity is maximally achieved 12 weeks after LVAD therapy and can continue even after explantation of the device. This effect varies, depending on the type of LVAD and exercise training. The available data in the literature on safety and benefits of exercise training in patients after LVAD implantation are limited, but the data that are available suggest that training trends to be safe and have an impact on exercise capacity in LVAD patients. Although no studies were identified on the role of cardiac rehabilitation programs in the management of LVAD patients, it appears that cardiac rehabilitation programs offer an ideal setting for the provision of supervised exercise training in this patient group.


Asunto(s)
Circulación Asistida , Terapia por Ejercicio/métodos , Insuficiencia Cardíaca , Corazón Auxiliar , Circulación Asistida/instrumentación , Circulación Asistida/métodos , Prueba de Esfuerzo , Tolerancia al Ejercicio , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/rehabilitación , Insuficiencia Cardíaca/cirugía , Humanos , Evaluación de Necesidades , Medición de Riesgo
4.
Curr Hypertens Rep ; 12(2): 61-6, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20424959

RESUMEN

Electrical activation of the carotid baroreceptor system is an attractive therapy for the treatment of resistant hypertension. In the past, several attempts were made to directly activate the baroreceptor system in humans, but the method had to be restricted to a few selected patients. Adverse effects, the need for better electrical devices and better surgical techniques, and the lack of knowledge about long-term effects has greatly hampered developments in this area for many years. Recently, a new and promising device was evaluated in a multicenter feasibility trial, which showed a clinically and statistically significant reduction in office systolic blood pressure (>20 mm Hg). This reduction could be sustained for at least 2 years with an acceptable safety profile. In the future, this new device may stimulate further application of electrical activation of the carotid baroreflex in treatment-resistant hypertension.


Asunto(s)
Barorreflejo/fisiología , Presión Sanguínea/fisiología , Arterias Carótidas/inervación , Hipertensión/fisiopatología , Presorreceptores/metabolismo , Animales , Circulación Asistida/instrumentación , Circulación Asistida/métodos , Diástole , Terapia por Estimulación Eléctrica , Electrodos Implantados , Estudios de Factibilidad , Humanos , Hipertensión/terapia , Sístole
5.
J Cardiovasc Electrophysiol ; 18(1): 106-9, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17229307

RESUMEN

Ventricular tachycardia (VT) in the setting of structural heart disease is challenging to treat with percutaneous catheter ablation due to the presence of complex substrate, multiple morphologies, hemodynamic instability, and epicardial circuits. When substrate-based approaches fail, however, it may be impossible to map and ablate hemodynamically unstable arrhythmias. We describe a novel approach to endocardial and epicardial mapping and ablation of hypotensive VT using a percutaneous left ventricular assist device in the electrophysiology laboratory, permitting near-surgical access to cardiac structures.


Asunto(s)
Circulación Asistida/métodos , Ablación por Catéter/métodos , Técnicas Electrofisiológicas Cardíacas/métodos , Corazón Auxiliar , Hipotensión/complicaciones , Taquicardia Ventricular/cirugía , Frecuencia Cardíaca/fisiología , Humanos , Hipotensión/fisiopatología , Masculino , Persona de Mediana Edad , Taquicardia Ventricular/complicaciones , Taquicardia Ventricular/fisiopatología
6.
Perfusion ; 19(2): 113-7, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15162926

RESUMEN

The vacuum-assisted venous drainage (VAVD) technique has been introduced with the utilization of small-bore venous cannulae to facilitate minimally invasive cardiac surgery and it has found widespread use for traditional surgical approaches. Although this technique was devised to increase venous return, it may cause a reduction of blood flow through a negative pressure effect on the raceway tubing. In this study, the potential of this system to increase the venous drainage was evaluated in vitro together with the measurements of delivered blood flow. The VAVD has been tested in association with normal gravitational drainage or as a substitute for gravitational drainage. The flow was calculated by multiplying the pump rate by the stroke volume and it was simultaneously measured by a magnetic flowmeter. A steady state maximal flow was defined as the flow that could maintain a constant level of fluid in the graduated canister used to act as the patient. Based on our results, the VAVD can increase venous drainage by as much as 50% above baseline levels. However, delivered blood flow may be overestimated, particularly when negative pressure values > 60 mmHg are employed. A 100 mmHg negative pressure may produce an overestimate of blood flow as great as 54% of the measured flow.


Asunto(s)
Circulación Asistida/instrumentación , Circulación Asistida/métodos , Transfusión de Sangre Autóloga/métodos , Velocidad del Flujo Sanguíneo , Humanos , Presión , Flujo Pulsátil , Factores de Riesgo , Vacio , Presión Venosa
7.
Semin Thorac Cardiovasc Surg ; 12(3): 229-37, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11052190

RESUMEN

We describe our clinical experience with 205 implantable left ventricular assist devices at the Cleveland Clinic between December 1991 and January 2000, along with manufacturers' data submitted to the Food and Drug Administration. In patients with end-stage cardiac failure who are suitable candidates for transplantation, these devices serve as excellent bridges to transplantation. Recent modifications have increased pump reliability and reduced thromboembolic rates. The vented electric HeartMate (Thermocardiosystems Inc, Woburn, MA) and the Novacor (Baxter-Novacor, Oakland, CA) left ventricular assist systems allow patients to be discharged from the hospital while awaiting a donor heart. Experience with long-term support is providing insights into permanent implantation of these devices as destination therapy. Although infection remains a major impediment to long-term support, patient-pump interactions leading to changes in the coagulation and immune systems are being recognized, and these interactions may have important implications with respect to thromboembolism, infection, and sensitization to human leukocyte antigens (HLAs). Better understanding of these factors may eventually lead to the development of permanently implantable pumps as an alternative to transplantation.


Asunto(s)
Circulación Asistida/métodos , Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Disfunción Ventricular Izquierda/terapia , Circulación Asistida/efectos adversos , Circulación Asistida/instrumentación , Insuficiencia Cardíaca/cirugía , Trasplante de Corazón , Implantación de Prótesis de Válvulas Cardíacas , Corazón Auxiliar/efectos adversos , Humanos , Ohio , Falla de Prótesis , Infecciones Relacionadas con Prótesis/etiología , Calidad de Vida , Tromboembolia/etiología , Resultado del Tratamiento
8.
ASAIO J ; 42(5): M402-6, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8944916

RESUMEN

It is known that deoxygenated blood is paramagnetic. A ferrofluidic actuator for an implantable artificial heart has been studied. The magnetic fluid consists of ferromagnetic magnetite particles (10 nm). If artificial cells encapsulating ferromagnetic particles are mixed in blood, the circulation is maintained by applying a magnetic field to the blood. An array of two poles of ring solenoids with a gap of 10 mm was mounted near the glass tube (7.60 mm inner diameter). The flux density was 0.236 Tesla. Two experiments were conducted using models of artificial cells: 1) the magnetic fluid and 2) the magnetic fluid and an iron cylinder (6.67 mm in diameter and 28.7 mm in length). A flow of 38 to 8 ml/min was obtained against a pressure of 12.5 to 16.3 mmHg in experiment 1, and 80 to 24 ml/min against a pressure of 53 to 240 mmHg in experiment 2. Calculation showed that magnetic fluids could move against a pressure of 100 mmHg if they had a magnetization of 113 kA/m (B = 0.236 Tesla). The magnetic fluid has a magnetization of 35.6 kA/m, whereas the magnetite is 479 kA/m, and that of iron 1398 kA/m. Artificial circulation with ferromagnetic artificial cells could be feasible if artificial cells with a magnetization of 113 kA/m are developed.


Asunto(s)
Circulación Asistida/métodos , Compuestos Férricos , Circulación Asistida/instrumentación , Ingeniería Biomédica , Estudios de Evaluación como Asunto , Técnicas In Vitro , Magnetismo/uso terapéutico , Modelos Cardiovasculares , Presión
9.
Plast Reconstr Surg ; 94(3): 490-5, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8047601

RESUMEN

Dynamic cardiomyoplasty is a technique for ventricular assistance indicated for the correction of left ventricle aneurysm and for cardiomyopathies in which heart transplantation is contraindicated. In this article, our first four patients to undergo cardiomyoplasty (from February 1991 until April 1992) with a left latissimus dorsi island flap, rotated into the thorax after a 3-week training period, are reviewed. Therapeutic indications were cardiomyopathy with contraindication for heart transplant in patients 1 and 4 and associated to surgery for left ventricle aneurysm for patients 2 and 3. Patient 1 died 4 months after surgery because of a cerebral embolism when he was at functional class II. The other three patients remain at functional class I, carrying out normal activities. All the data were evaluated with the paired t test. Ejection fraction values (obtained through echocardiography and scintigraphy studies) and maximum minute flow rate of blood (measured with an echo-Doppler) have increased significantly (p < 0.001, p < 0.05, and p < 0.01, respectively) after heart surgery. Clinical improvement has been found after cardiomyoplasty, which correlates with an increase in ejection fraction and maximum minute flow rate of blood.


Asunto(s)
Circulación Asistida/métodos , Cardiomiopatía Dilatada/cirugía , Terapia por Estimulación Eléctrica , Aneurisma Cardíaco/cirugía , Músculos/cirugía , Colgajos Quirúrgicos/métodos , Adulto , Anciano , Cardiomiopatía Dilatada/fisiopatología , Aneurisma Cardíaco/fisiopatología , Humanos , Persona de Mediana Edad , Músculos/fisiología
10.
Ann Thorac Surg ; 58(1): 121-7, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8037509

RESUMEN

The aim of this study was to quantify the effects of three different configurations of cardiomyoplasty on coronary blood flow in an acute dog model. Thirteen dogs had both latissimus dorsi muscles harvested and transposed to the chest. Coronary blood flow was measured using Doppler cuff probes on the left anterior descending and circumflex coronary arteries during each of three cardiomyoplasty configurations: left posterior, right anterior, and double. Multiple beat measures were made of systolic and diastolic flow during a control protocol and a subsequent protocol with the muscle(s) paced. Significant flow reductions during pacing were observed in the left anterior descending coronary artery during left posterior (17%, p = 0.003), right anterior (29%, p < 0.0001), and double (35%, p = 0.0001) myoplasty. Similar reductions occurred in the circumflex artery (14%, p = 0.0009; 20%, p = 0.001; 27%, p = 0.0053). The net flow over an entire pacing cycle also was reduced significantly: left anterior descending artery (11%, p = 0.0035; 23%, p = 0.0001; 23%, p = 0.0047) and circumflex artery (10%, p = 0.0025; 17%, p = 0.0018; 21%, p = 0.0091). Thus, in the acute setting cardiomyoplasty depresses coronary blood flow. A chronic setting will be needed to determine the ultimate significance of these results.


Asunto(s)
Circulación Asistida/métodos , Circulación Coronaria/fisiología , Terapia por Estimulación Eléctrica , Músculos/trasplante , Isquemia Miocárdica/etiología , Colgajos Quirúrgicos , Animales , Circulación Asistida/efectos adversos , Perros , Contracción Miocárdica/fisiología
12.
J Thorac Cardiovasc Surg ; 107(3): 868-78, 1994 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8127116

RESUMEN

Past reports suggest that structural changes within the latissimus dorsi muscle occur with chronic electrical stimulation during cardiomyoplasty. However, the specific changes in the structure of the latissimus dorsi muscle and the relation to muscle contractile function with cardiomyoplasty are unknown. Accordingly, this study examined regional changes in latissimus dorsi muscle structure and function after cardiomyoplasty. The left latissimus dorsi muscle was mobilized and wrapped around the heart in pigs with the use of standardized techniques and the latissimus dorsi muscle chronically paced at ambient heart rates (90 beats/min; 20 Hz, 5 V amplitude, n = 6). After 6 weeks, the paced latissimus dorsi muscle and the contralateral control muscle were removed and divided into proximal (0 to 3 cm), middle (3 to 6 cm), and distal (6 to 12 cm) regions. By computer-assisted morphometry, muscle cell myofibril volume, cross-sectional area, and collagen percent area were determined. In the paced latissimus dorsi muscle, myofibril volumes increased by more than 50% in the proximal and middle regions compared with those in the contralateral control muscle. However, myofibril volumes were significantly lower in the distal region of the paced latissimus dorsi muscle compared with those in control muscles (33% +/- 5% versus 20% +/- 3%, p < 0.05). In the paced latissimus dorsi muscle, cross-sectional area was significantly reduced from that of control muscles in all regions. A further reduction in cross-sectional area was noted in the distal region of the paced latissimus dorsi muscle compared with that in both the contralateral control muscle and the proximal and middle regions of the paced latissimus dorsi muscle. Collagen content significantly increased in the paced latissimus dorsi muscle compared with that in control muscle with a more fibrotic pattern observed in the distal region. Latissimus dorsi muscle strips (less than 2 mm2 cross-sectional area) were harvested, and peak and velocity of tension development were examined after field electrical stimulation at 0.2 to 1.2 Hz. At 0.2 Hz, the velocity of tension development was unchanged in the paced latissimus dorsi muscle compared with that in control muscle. However, peak tension development degraded by only 28% in the paced latissimus dorsi muscles but fell by 51% in control muscles with increased stimulation frequencies. In summary, the contractile function of the chronically stimulated latissimus dorsi muscle was associated with fatigue resistance and increased contractile protein content. However, more distal regions of the paced latissimus dorsi muscle demonstrated atrophy and fibrosis.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Circulación Asistida/métodos , Terapia por Estimulación Eléctrica , Contracción Muscular/fisiología , Músculos/citología , Músculos/fisiología , Animales , Colágeno/análisis , Microscopía Electrónica , Proteínas Musculares/análisis , Músculos/trasplante , Colgajos Quirúrgicos , Porcinos , Factores de Tiempo
13.
Circulation ; 89(3): 1032-40, 1994 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8124788

RESUMEN

BACKGROUND: Skeletal muscle can be used for cardiac assistance after electrical stimulation over a period of several weeks. This will adapt it to do chronic work with no resulting fatigue. The result of this procedure, however, is a reduction of 80% in muscle power, > 60% in muscle mass, and approximately 85% in contractile speed. To minimize these disadvantages, the following study was done to develop and test a method to dynamically train skeletal muscle ventricles (SMVs). METHODS AND RESULTS: Barrel-shaped SMVs were tested in 15 Jersey calves. They were made from the latissimus dorsi muscle, which was wrapped around an elastic silicone training device. Six SMVs were used extrathoracically in a single layer and nine intrathoracically in a double layer. With dynamic training preserving contractile speed, the output increased to approximately 5 L/min, the systolic pressure increased to > 200 mm Hg, and power developed to approximately 10 W after 3 months of dynamic training. The contractile speed of dynamically trained SMVs was between 250 and 700 mm/s. The diameter of the latissimus dorsi muscle increased to three times that of the corresponding contralateral muscle. CONCLUSIONS: The combination of electrical conditioning with dynamic training of the SMVs resulted in a strong muscle pump that did not develop fatigue. Dynamic training for skeletal muscle represents a new and promising method for providing powerful autologous cardiac assist.


Asunto(s)
Circulación Asistida/métodos , Terapia por Estimulación Eléctrica , Contracción Muscular/fisiología , Músculos/fisiología , Colgajos Quirúrgicos/métodos , Animales , Bovinos , Diseño de Equipo , Modelos Cardiovasculares , Elastómeros de Silicona
15.
Eur J Cardiothorac Surg ; 8(4): 214-9, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-8031566

RESUMEN

In 12 sheep the left latissimus dorsi muscles (LD) were conditioned by chronic electrostimulation with a pulse generator (Itrel, Medtronic). Six animals (group B) received a weekly intramuscular injection of an anabolic steroid (Metenolon). After 14 weeks the contraction parameters of the left LDs (group A and B) and right LDs (control group) were investigated. The increase in weight of the conditioned LDs was 11.07% (+/- 1.06%) in group A and 79.97% (+/- 40.8; P < 0.05) in group B. The force capacity under stimulation patterns which were just tetanic was 1.15 kp in group A and 4.13 kp in group B (P < 0.05); under supramaximal stimulation patterns it was 4.23 kp (A) and 6.0 kp (B) (P = ns). The force time relation (dF/dt) was 6.7 kp/s for the left LDs in group A versus 16.4 kp/s for the right LDs (P < 0.01); in group B it was 5.13 kp/s for the left LDs versus 15.8 kp/s for the control muscles (P < 0.05). The maximal force (Fmax) per 100 g muscle weight did not differ significantly (A: 2.42 kp/100 g; B: 2.52 kp/100 g). In conclusion, the LD muscles which were subjected to both anabolic therapy and electrical stimulation showed a significant increase in their force capacity due to an enormous increase in mass. Fibre type transformation was complete only in group B. No fibre deterioration was observable in either group. No anabolic side effects were detected in the animals. With the use of anabolic steroids, therefore, a clearer direct increase in contractility on the left ventricle should be expected ("squeezing" theory), as well as a contribution to reduction in wall tension and myocardial oxygen consumption, respectively, according to Laplace's Law (via the considerable increase in thickness).


Asunto(s)
Anabolizantes/farmacología , Circulación Asistida/métodos , Terapia por Estimulación Eléctrica , Metenolona/farmacología , Contracción Muscular/efectos de los fármacos , Músculos/efectos de los fármacos , Animales , Femenino , Ventrículos Cardíacos , Contracción Muscular/fisiología , Músculos/fisiología , Ovinos , Colgajos Quirúrgicos
16.
Nihon Kyobu Geka Gakkai Zasshi ; 41(12): 2301-10, 1993 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-8288918

RESUMEN

This study was undertaken to examine the effect of cardiac assist and left ventricular function after dynamic cardiomyoplasty (DCMP). In the first group (GI) of 10 mongrel dogs DCMP was drived immediately after wrapping both ventricles by latissmus dorsi muscle flap (LDMF). In the second group (GII) of 10 mongrel dogs DCMP was derived over 6 weeks after production of DCMP for achievement of complete adhesion between LDMF and myocardium. In the both groups, aortic pressure, cardiac output, left ventricular systolic pressure, and ejection fraction of the left ventricle were significantly increased by DCMP driving (p < 0.001). But left ventricular systolic pressure was remarkably increased in GII compared with that of GI (21.2 +/- 10.2% versus 14.0 +/- 9.6%, p < 0.001), and end diastolic pressure of the left ventricle was apparently decreased in GII (61.6 +/- 42.3% p < 0.05). Thus, satisfactory results were recognized that cardiac assist for left ventricular function was enhanced after completion of adhesion between myocardium and LDMF. Echocardiography in GII demonstrated that left ventricular systolic dimention was significantly decreased from 33.8 +/- 1.0 mm to 27.6 +/- 1.2 mm (p < 0.001). Thus, left ventricular fractional shortening was significantly increased from 24.0 +/- 2.4% to 38.0 +/- 2.6% (p < 0.001). However, left ventricle end-diastolic dimention was not changed even during DCMP driving. So disturbance in left ventricular function during diastole could not be recognized. In conclusion, especially after adhesion of both muscles of LDMF and myocardium, effect of cardiac assist was remarkably enhanced, and disturbance of diastolic function of the left ventricle could not be observed.


Asunto(s)
Circulación Asistida/métodos , Hemodinámica/fisiología , Músculos/trasplante , Colgajos Quirúrgicos/métodos , Función Ventricular Izquierda/fisiología , Animales , Perros , Terapia por Estimulación Eléctrica , Femenino , Insuficiencia Cardíaca/cirugía , Ventrículos Cardíacos/cirugía , Masculino
17.
Circulation ; 88(5 Pt 2): II298-303, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8222169

RESUMEN

BACKGROUND: We hypothesized that left ventricular function could be improved with cardiomyoplasty using the right latissimus dorsi. METHODS AND RESULTS: Five dogs underwent cardiomyoplasty using the right latissimus dorsi. Left ventricular volume and pressure were measured using sonomicrometry and a micromanometer catheter, respectively. Pressure volume loops were recorded with the muscle stimulated at 1:2 and with transient caval occlusion. During stimulated beats, there were significant increases in stroke work (13.90 +/- 4.49 vs 9.78 +/- 3.81 g/m, P < .01), preload recruitable stroke work (0.766 +/- 0.110 vs 0.594 +/- 0.207 g.m-1 x m-3, P < .05), and stroke volume (15 +/- 4 vs 10 +/- 3 mL, P < .05) when compared with unstimulated beats. There were no changes in diastolic filling. This operation was done in 11 patients, with no operative deaths. Six weeks after surgery, resting left ventricular ejection fraction (LVEF) increased from 25 +/- 1.6% to 35 +/- 3% (P < .05), and left ventricular end-diastolic volume (LVEDV) decreased from 365 +/- 18 to 307 +/- 24 mL, (P < .05). Nine patients were alive at 6 months. Preoperative and 6-month LVEF and LVEDV for those 9 patients were 26 +/- 2% and 29 +/- 2% (P = NS) and 316 +/- 23 and 261 +/- 22 mL (P < .05), respectively. CONCLUSIONS: Long-term studies are needed to determine if these changes will improve patient survival.


Asunto(s)
Terapia por Estimulación Eléctrica , Insuficiencia Cardíaca/cirugía , Músculos/cirugía , Colgajos Quirúrgicos/métodos , Función Ventricular Izquierda/fisiología , Animales , Circulación Asistida/métodos , Cateterismo Cardíaco , Perros , Electrocardiografía , Humanos , Masculino , Contracción Muscular/fisiología , Contracción Miocárdica/fisiología , Volumen Sistólico/fisiología
18.
Circulation ; 88(5 Pt 2): II304-8, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8222171

RESUMEN

BACKGROUND: Dynamic cardiomyoplasty is a relatively new surgical procedure proposed for treatment of severe myocardial failure. Limited clinical experience suggests that this procedure reverses congestive heart failure, improving the long-term survival. METHODS AND RESULTS: In this investigation, the late effects (16.5 +/- 4.8 months after surgery) of cardiomyoplasty on left ventricular mechanics and diastolic filling were studied in eight male patients (mean age, 45 +/- 7 years). The investigation was performed with the myostimulator on and off (24 +/- 1 hours off) using a microtip catheter to obtain the left ventricular pressures simultaneously with Doppler (inflow velocities) and M-mode and two-dimensional echocardiographic recordings. Statistical comparisons were made with Student's t test for paired data. Dynamic cardiomyoplasty increased the maximal elastance (17 +/- 1 versus 21 +/- 1 mm Hg/cm, P = .006) and decreased the systolic wall stress (253 +/- 17 versus 190 +/- 12 g/cm2, P = .029). Left ventricular end-diastolic pressure decreased (27.1 +/- 2.8 versus 17.6 +/- 1.7 mm Hg, P = .019), as did end-diastolic circumferential wall stress (69 +/- 8 versus 37 +/- 5 g/cm2, P = .002). The chamber and muscle stiffnesses decreased (120 +/- 31 versus 52 +/- 11 mm Hg/cm, P = .017; 994 +/- 185 versus 426 +/- 76 g/cm2, P = .002, respectively). The pattern of left ventricular diastolic filling changed, with a decrease of early peak flow (231 +/- 20 versus 217 +/- 21 mL/s, P = .022), of deceleration time (163 +/- 28 versus 116 +/- 26 seconds, P = .001), and of flow area during rapid filling (105 +/- 15 versus 75 +/- 12 mL, P = .004) and an increase of flow area during atrial contraction (39 +/- 4 versus 88 +/- 9 mL, P = .001). CONCLUSIONS: Our detailed evaluation of left ventricular mechanics demonstrates that cardiomyoplasty has significant multiple beneficial effects on dilated myopathic heart.


Asunto(s)
Cardiomiopatía Dilatada/cirugía , Terapia por Estimulación Eléctrica , Músculos/cirugía , Colgajos Quirúrgicos/métodos , Función Ventricular Izquierda/fisiología , Circulación Asistida/métodos , Cateterismo Cardíaco , Cardiomiopatía Dilatada/epidemiología , Cardiomiopatía Dilatada/fisiopatología , Ecocardiografía Doppler , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Contracción Muscular/fisiología , Contracción Miocárdica/fisiología , Volumen Sistólico/fisiología , Factores de Tiempo
19.
Pacing Clin Electrophysiol ; 16(10): 2012-21, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7694248

RESUMEN

When treating severe cardiac failure with dynamic cardiomyoplasty, knowledge about the optimal way of stimulating the latissimus dorsi (LD) muscle is of obvious importance. We evaluated a new stimulation protocol in four goats using in situ electrical stimulation of the left LD muscle. Stimulation was started using a burst of two pulses with an interpulse interval of 100 msec for 50 bursts/min. The number of pulses was increased every 2 weeks concomitant with a decrease in interpulse interval. This resulted after 12 weeks in 60 bursts/min using bursts of six pulses with an interpulse interval of 20 msec after 12 weeks. Force measurements, which were done every 2 weeks, showed an early decrease in contraction and relaxation speed as reflected in the ripple (= interstimulus amplitude/peak force amplitude measured at 10 Hz). Fatigue resistance increased significantly within 4 weeks of conditioning as indicated by preservation of force, positive dF/dt, and negative dF/dt. Full preservation of these variables was seen even during a 1-hour fatigue test at the end of the conditioning period. Skeletal muscle enzyme activity as an indicator of muscle damage showed a significant rise in creatine kinase enzyme activity only on the first day following the start of LD stimulation. LD muscle biopsies revealed almost complete transformation to type I muscle fibers with a significant increase in capillary/fiber ratio when compared to the nonstimulated LD muscle. However, some biopsies, in particular near the electrodes, did show some signs of skeletal muscle damage. Contraction characteristics of the fully transformed LD muscles were tested by increasing the number of bursts of six pulses from 50/min to 100/min. Interpulse intervals of 20 and 33 msec were used. These tests revealed that maximal force, positive dF/dt, and negative dF/dt was reached with 50 bursts/min using a six pulse burst with interpulse intervals of 20 msec.


Asunto(s)
Circulación Asistida/métodos , Terapia por Estimulación Eléctrica , Músculos/trasplante , Colgajos Quirúrgicos , Animales , Cabras
20.
Ann Thorac Surg ; 56(3): 418-24; discussion 424-5, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8379711

RESUMEN

Transplantation is effective therapy for congestive heart failure (CHF), but few donors are available and many patients are not candidates. We have therefore developed a surgical approach to CHF that offers several options. Patients with no medical or psychosocial contraindications are listed for heart transplantation (HT). Patients with ischemia on thallium scan and operable vessels have coronary artery bypass grafting (CABG). Patients who are not candidates for either of these options are evaluated for cardiomyoplasty (CMP). One hundred nineteen patients have now had operation for CHF: 61 had HT, 27 had CABG, and 31 had CMP. The mean ages of the three groups were 51 +/- 1 years, 59 +/- 3 years, and 56 +/- 2 years, respectively. Preoperative pulmonary capillary wedge pressure was 22 +/- 1.1 mm Hg in the HT group, 20 +/- 2.9 mm Hg in the CABG group, and 19 +/- 1.9 mm Hg in the CMP group. Left ventricular ejection fraction improved in operative survivors in each group: 0.23 +/- 0.01 to 0.69 +/- 0.01 for the HT group, 0.31 +/- 0.01 to 0.39 +/- 0.02 for the CABG group, and 0.26 +/- 0.01 to 0.33 +/- 0.03 for the CMP group (p < 0.01). The operative mortality rate was 7% for the HT patients, 4% for the CABG patients, and 16% for the CMP patients, and 1-year survival rates for those discharged were 94%, 91%, and 65%, respectively. Long-term survivors of CMP and CABG are functionally improved but still require medical therapy for CHF. Survivors of HT do not have CHF but suffer the consequences of immunosuppression.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Circulación Asistida/métodos , Puente de Arteria Coronaria , Insuficiencia Cardíaca/cirugía , Trasplante de Corazón , Terapia por Estimulación Eléctrica , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Músculos/trasplante , Colgajos Quirúrgicos , Tasa de Supervivencia , Factores de Tiempo , Función Ventricular Izquierda/fisiología
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